VME Bus drivers and framework for Linux

From: Martyn Welch <[email protected]>

This framework aims to colelese, extend and improve the VME Linux drivers found at vmelinux.org, universe2.sourceforge.net and openfmi.net/frs/?group_id=144. The last 2 drivers appear to be forks of the original code found at vmelinux.org though have extended the codebase.

Signed-off-by Martyn Welch <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/staging/Kconfig          |    2 
 drivers/staging/Makefile         |    1 
 drivers/staging/vme/Kconfig      |   17 
 drivers/staging/vme/Makefile     |    7 
 drivers/staging/vme/vme.c        | 1371 +++++++++++++++++++++++++++++++++++++++
 drivers/staging/vme/vme.h        |  153 ++++
 drivers/staging/vme/vme_bridge.h |  249 +++++++
 7 files changed, 1800 insertions(+)

drivers/staging/Kconfig +2 -0

@@ -139,5 +139,7 @@ source "drivers/staging/udlfb/Kconfig"
 
 source "drivers/staging/hv/Kconfig"
 
+source "drivers/staging/vme/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile +1 -0

@@ -51,3 +51,4 @@ obj-$(CONFIG_FB_UDL)		+= udlfb/
 obj-$(CONFIG_MSM_ADSP)		+= dream/qdsp5/ dream/smd/
 obj-$(CONFIG_MSM_CAMERA)	+= dream/camera/
 obj-$(CONFIG_HYPERV)		+= hv/
+obj-$(CONFIG_VME)		+= vme/

drivers/staging/vme/Kconfig new file +17 -0

@@ -0,0 +1,17 @@
+#
+# VME configuration.
+#
+
+menuconfig VME
+	tristate "VME bridge support"
+	depends on PCI
+	---help---
+	  If you say Y here you get support for the VME bridge Framework.
+
+if VME
+
+#source "drivers/staging/vme/bridges/Kconfig"
+#
+#source "drivers/staging/vme/devices/Kconfig"
+
+endif # VME

drivers/staging/vme/Makefile new file +7 -0

@@ -0,0 +1,7 @@
+#
+# Makefile for the VME bridge device drivers.
+#
+obj-$(CONFIG_VME)		+= vme.o
+
+#obj-y				+= bridges/
+#obj-y				+= devices/

drivers/staging/vme/vme_bridge.h new file +249 -0

@@ -0,0 +1,249 @@
+#ifndef _VME_BRIDGE_H_
+#define _VME_BRIDGE_H_
+
+#define VME_CRCSR_BUF_SIZE (508*1024)
+#define VME_SLOTS_MAX 32
+/*
+ * Resource structures
+ */
+struct vme_master_resource {
+	struct list_head list;
+	struct vme_bridge *parent;
+	/*
+	 * We are likely to need to access the VME bus in interrupt context, so
+	 * protect master routines with a spinlock rather than a semaphore.
+	 */
+	spinlock_t lock;
+	int locked;
+	int number;
+	vme_address_t address_attr;
+	vme_cycle_t cycle_attr;
+	vme_width_t width_attr;
+	struct resource pci_resource;	/* XXX Rename to be bus agnostic */
+	void *kern_base;
+};
+
+struct vme_slave_resource {
+	struct list_head list;
+	struct vme_bridge *parent;
+	struct semaphore sem;
+	int locked;
+	int number;
+	vme_address_t address_attr;
+	vme_cycle_t cycle_attr;
+};
+
+struct vme_dma_pattern {
+	u32 pattern;
+	vme_pattern_t type;
+};
+
+struct vme_dma_pci {
+	dma_addr_t address;
+};
+
+struct vme_dma_vme {
+	unsigned long long address;
+	vme_address_t aspace;
+	vme_cycle_t cycle;
+	vme_width_t dwidth;
+};
+
+struct vme_dma_list {
+	struct list_head list;
+	struct vme_dma_resource *parent;
+	struct list_head entries;
+	struct semaphore sem;
+};
+
+struct vme_dma_resource {
+	struct list_head list;
+	struct vme_bridge *parent;
+	struct semaphore sem;
+	int locked;
+	int number;
+	struct list_head pending;
+	struct list_head running;
+};
+
+struct vme_bus_error {
+	struct list_head list;
+	unsigned long long address;
+	u32 attributes;
+};
+
+struct vme_callback {
+	void (*func)(int, int, void*);
+	void *priv_data;
+};
+
+struct vme_irq {
+	int count;
+	struct vme_callback callback[255];
+};
+
+/* Allow 16 characters for name (including null character) */
+#define VMENAMSIZ 16
+
+/* This structure stores all the information about one bridge
+ * The structure should be dynamically allocated by the driver and one instance
+ * of the structure should be present for each VME chip present in the system.
+ *
+ * Currently we assume that all chips are PCI-based
+ */
+struct vme_bridge {
+        char name[VMENAMSIZ];
+	int num;
+	struct list_head master_resources;
+	struct list_head slave_resources;
+	struct list_head dma_resources;
+
+	struct list_head vme_errors;	/* List for errors generated on VME */
+
+	/* Bridge Info - XXX Move to private structure? */
+	struct device *parent;	/* Generic device struct (pdev->dev for PCI) */
+	void * base;		/* Base Address of device registers */
+
+	struct device dev[VME_SLOTS_MAX];	/* Device registered with
+						 * device model on VME bus
+						 */
+
+	/* Interrupt callbacks */
+	struct vme_irq irq[7];
+
+	/* Slave Functions */
+	int (*slave_get) (struct vme_slave_resource *, int *,
+		unsigned long long *, unsigned long long *, dma_addr_t *,
+		vme_address_t *, vme_cycle_t *);
+	int (*slave_set) (struct vme_slave_resource *, int, unsigned long long,
+		unsigned long long, dma_addr_t, vme_address_t, vme_cycle_t);
+
+	/* Master Functions */
+	int (*master_get) (struct vme_master_resource *, int *,
+		unsigned long long *, unsigned long long *, vme_address_t *,
+		vme_cycle_t *, vme_width_t *);
+	int (*master_set) (struct vme_master_resource *, int,
+		unsigned long long, unsigned long long,  vme_address_t,
+		vme_cycle_t, vme_width_t);
+	ssize_t (*master_read) (struct vme_master_resource *, void *, size_t,
+		loff_t);
+	ssize_t (*master_write) (struct vme_master_resource *, void *, size_t,
+		loff_t);
+	unsigned int (*master_rmw) (struct vme_master_resource *, unsigned int,
+		unsigned int, unsigned int, loff_t);
+
+	/* DMA Functions */
+	int (*dma_list_add) (struct vme_dma_list *, struct vme_dma_attr *,
+		struct vme_dma_attr *, size_t);
+	int (*dma_list_exec) (struct vme_dma_list *);
+	int (*dma_list_empty) (struct vme_dma_list *);
+
+	/* Interrupt Functions */
+	int (*request_irq) (int, int, void (*cback)(int, int, void*), void *);
+	void (*free_irq) (int, int);
+	int (*generate_irq) (int, int);
+
+	/* Location monitor functions */
+	int (*lm_set) (unsigned long long, vme_address_t, vme_cycle_t);
+	int (*lm_get) (unsigned long long *, vme_address_t *, vme_cycle_t *);
+	int (*lm_attach) (int, void (*callback)(int));
+	int (*lm_detach) (int);
+
+	/* CR/CSR space functions */
+	int (*slot_get) (void);
+	/* Use standard master read and write functions to access CR/CSR */
+
+#if 0
+	int (*set_prefetch) (void);
+	int (*get_prefetch) (void);
+	int (*set_arbiter) (void);
+	int (*get_arbiter) (void);
+	int (*set_requestor) (void);
+	int (*get_requestor) (void);
+#endif
+};
+
+int vme_register_bridge (struct vme_bridge *);
+void vme_unregister_bridge (struct vme_bridge *);
+
+#endif /* _VME_BRIDGE_H_ */
+
+#if 0
+/*
+ *  VMEbus GET INFO Arg Structure
+ */
+struct vmeInfoCfg {
+	int vmeSlotNum;		/*  VME slot number of interest */
+	int boardResponded;	/* Board responded */
+	char sysConFlag;	/*  System controller flag */
+	int vmeControllerID;	/*  Vendor/device ID of VME bridge */
+	int vmeControllerRev;	/*  Revision of VME bridge */
+	char osName[8];		/*  Name of OS e.g. "Linux" */
+	int vmeSharedDataValid;	/*  Validity of data struct */
+	int vmeDriverRev;	/*  Revision of VME driver */
+	unsigned int vmeAddrHi[8];	/* Address on VME bus */
+	unsigned int vmeAddrLo[8];	/* Address on VME bus */
+	unsigned int vmeSize[8];	/* Size on VME bus */
+	unsigned int vmeAm[8];	/* Address modifier on VME bus */
+	int reserved;		/* For future use */
+};
+typedef struct vmeInfoCfg vmeInfoCfg_t;
+
+/*
+ *  VMEbus Requester Arg Structure
+ */
+struct vmeRequesterCfg {
+	int requestLevel;	/*  Requester Bus Request Level */
+	char fairMode;		/*  Requester Fairness Mode Indicator */
+	int releaseMode;	/*  Requester Bus Release Mode */
+	int timeonTimeoutTimer;	/*  Master Time-on Time-out Timer */
+	int timeoffTimeoutTimer;	/*  Master Time-off Time-out Timer */
+	int reserved;		/* For future use */
+};
+typedef struct vmeRequesterCfg vmeRequesterCfg_t;
+
+/*
+ *  VMEbus Arbiter Arg Structure
+ */
+struct vmeArbiterCfg {
+	vme_arbitration_t arbiterMode;	/*  Arbitration Scheduling Algorithm */
+	char arbiterTimeoutFlag;	/*  Arbiter Time-out Timer Indicator */
+	int globalTimeoutTimer;	/*  VMEbus Global Time-out Timer */
+	char noEarlyReleaseFlag;	/*  No Early Release on BBUSY */
+	int reserved;		/* For future use */
+};
+typedef struct vmeArbiterCfg vmeArbiterCfg_t;
+
+
+/*
+ *  VMEbus RMW Configuration Data
+ */
+struct vmeRmwCfg {
+	unsigned int targetAddrU;	/*  VME Address (Upper) to trigger RMW cycle */
+	unsigned int targetAddr;	/*  VME Address (Lower) to trigger RMW cycle */
+	vme_address_t addrSpace;	/*  VME Address Space */
+	int enableMask;		/*  Bit mask defining the bits of interest */
+	int compareData;	/*  Data to be compared with the data read */
+	int swapData;		/*  Data written to the VMEbus on success */
+	int maxAttempts;	/*  Maximum times to try */
+	int numAttempts;	/*  Number of attempts before success */
+	int reserved;		/* For future use */
+
+};
+typedef struct vmeRmwCfg vmeRmwCfg_t;
+
+/*
+ *  VMEbus Location Monitor Arg Structure
+ */
+struct vmeLmCfg {
+	unsigned int addrU;	/*  Location Monitor Address upper */
+	unsigned int addr;	/*  Location Monitor Address lower */
+	vme_address_t addrSpace;	/*  Address Space */
+	int userAccessType;	/*  User/Supervisor Access Type */
+	int dataAccessType;	/*  Data/Program Access Type */
+	int lmWait;		/* Time to wait for access */
+	int lmEvents;		/* Lm event mask */
+	int reserved;		/* For future use */
+};
+typedef struct vmeLmCfg vmeLmCfg_t;
+#endif

drivers/staging/vme/vme.c new file +1371 -0

@@ -0,0 +1,1371 @@
+/*
+ * VME Bridge Framework
+ *
+ * Author: Martyn Welch <[email protected]>
+ * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * Based on work by Tom Armistead and Ajit Prem
+ * Copyright 2004 Motorola Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/poll.h>
+#include <linux/highmem.h>
+#include <linux/interrupt.h>
+#include <linux/pagemap.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/syscalls.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+
+#include "vme.h"
+#include "vme_bridge.h"
+
+/* Bitmask and semaphore to keep track of bridge numbers */
+static unsigned int vme_bus_numbers;
+DECLARE_MUTEX(vme_bus_num_sem);
+
+static void __exit vme_exit (void);
+static int __init vme_init (void);
+
+
+/*
+ * Find the bridge resource associated with a specific device resource
+ */
+static struct vme_bridge *dev_to_bridge(struct device *dev)
+{
+	return dev->platform_data;
+}
+
+/*
+ * Find the bridge that the resource is associated with.
+ */
+static struct vme_bridge *find_bridge(struct vme_resource *resource)
+{
+	/* Get list to search */
+	switch (resource->type) {
+	case VME_MASTER:
+		return list_entry(resource->entry, struct vme_master_resource,
+			list)->parent;
+		break;
+	case VME_SLAVE:
+		return list_entry(resource->entry, struct vme_slave_resource,
+			list)->parent;
+		break;
+	case VME_DMA:
+		return list_entry(resource->entry, struct vme_dma_resource,
+			list)->parent;
+		break;
+	default:
+		printk(KERN_ERR "Unknown resource type\n");
+		return NULL;
+		break;
+	}
+}
+
+/*
+ * Allocate a contiguous block of memory for use by the driver. This is used to
+ * create the buffers for the slave windows.
+ *
+ * XXX VME bridges could be available on buses other than PCI. At the momment
+ *     this framework only supports PCI devices.
+ */
+void * vme_alloc_consistent(struct vme_resource *resource, size_t size,
+	dma_addr_t *dma)
+{
+	struct vme_bridge *bridge;
+	struct pci_dev *pdev;
+
+	if(resource == NULL) {
+		printk("No resource\n");
+		return NULL;
+	}
+
+	bridge = find_bridge(resource);
+	if(bridge == NULL) {
+		printk("Can't find bridge\n");
+		return NULL;
+	}
+
+	/* Find pci_dev container of dev */
+	if (bridge->parent == NULL) {
+		printk("Dev entry NULL\n");
+		return NULL;
+	}
+	pdev = container_of(bridge->parent, struct pci_dev, dev);
+
+	return pci_alloc_consistent(pdev, size, dma);
+}
+EXPORT_SYMBOL(vme_alloc_consistent);
+
+/*
+ * Free previously allocated contiguous block of memory.
+ *
+ * XXX VME bridges could be available on buses other than PCI. At the momment
+ *     this framework only supports PCI devices.
+ */
+void vme_free_consistent(struct vme_resource *resource, size_t size,
+	void *vaddr, dma_addr_t dma)
+{
+	struct vme_bridge *bridge;
+	struct pci_dev *pdev;
+
+	if(resource == NULL) {
+		printk("No resource\n");
+		return;
+	}
+
+	bridge = find_bridge(resource);
+	if(bridge == NULL) {
+		printk("Can't find bridge\n");
+		return;
+	}
+
+	/* Find pci_dev container of dev */
+	pdev = container_of(bridge->parent, struct pci_dev, dev);
+
+	pci_free_consistent(pdev, size, vaddr, dma);
+}
+EXPORT_SYMBOL(vme_free_consistent);
+
+size_t vme_get_size(struct vme_resource *resource)
+{
+	int enabled, retval;
+	unsigned long long base, size;
+	dma_addr_t buf_base;
+	vme_address_t aspace;
+	vme_cycle_t cycle;
+	vme_width_t dwidth;
+
+	switch (resource->type) {
+	case VME_MASTER:
+		retval = vme_master_get(resource, &enabled, &base, &size,
+			&aspace, &cycle, &dwidth);
+
+		return size;
+		break;
+	case VME_SLAVE:
+		retval = vme_slave_get(resource, &enabled, &base, &size,
+			&buf_base, &aspace, &cycle);
+
+		return size;
+		break;
+	case VME_DMA:
+		return 0;
+		break;
+	default:
+		printk(KERN_ERR "Unknown resource type\n");
+		return 0;
+		break;
+	}
+}
+EXPORT_SYMBOL(vme_get_size);
+
+static int vme_check_window(vme_address_t aspace, unsigned long long vme_base,
+	unsigned long long size)
+{
+	int retval = 0;
+
+	switch (aspace) {
+	case VME_A16:
+		if (((vme_base + size) > VME_A16_MAX) ||
+				(vme_base > VME_A16_MAX))
+			retval = -EFAULT;
+		break;
+	case VME_A24:
+		if (((vme_base + size) > VME_A24_MAX) ||
+				(vme_base > VME_A24_MAX))
+			retval = -EFAULT;
+		break;
+	case VME_A32:
+		if (((vme_base + size) > VME_A32_MAX) ||
+				(vme_base > VME_A32_MAX))
+			retval = -EFAULT;
+		break;
+	case VME_A64:
+		/*
+		 * Any value held in an unsigned long long can be used as the
+		 * base
+		 */
+		break;
+	case VME_CRCSR:
+		if (((vme_base + size) > VME_CRCSR_MAX) ||
+				(vme_base > VME_CRCSR_MAX))
+			retval = -EFAULT;
+		break;
+	case VME_USER1:
+	case VME_USER2:
+	case VME_USER3:
+	case VME_USER4:
+		/* User Defined */
+		break;
+	default:
+		printk("Invalid address space\n");
+		retval = -EINVAL;
+		break;
+	}
+
+	return retval;
+}
+
+/*
+ * Request a slave image with specific attributes, return some unique
+ * identifier.
+ */
+struct vme_resource * vme_slave_request(struct device *dev,
+	vme_address_t address, vme_cycle_t cycle)
+{
+	struct vme_bridge *bridge;
+	struct list_head *slave_pos = NULL;
+	struct vme_slave_resource *allocated_image = NULL;
+	struct vme_slave_resource *slave_image = NULL;
+	struct vme_resource *resource = NULL;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		goto err_bus;
+	}
+
+	/* Loop through slave resources */
+	list_for_each(slave_pos, &(bridge->slave_resources)) {
+		slave_image = list_entry(slave_pos,
+			struct vme_slave_resource, list);
+
+		if (slave_image == NULL) {
+			printk("Registered NULL Slave resource\n");
+			continue;
+		}
+
+		/* Find an unlocked and compatible image */
+		down(&(slave_image->sem));
+		if(((slave_image->address_attr & address) == address) &&
+			((slave_image->cycle_attr & cycle) == cycle) &&
+			(slave_image->locked == 0)) {
+
+			slave_image->locked = 1;
+			up(&(slave_image->sem));
+			allocated_image = slave_image;
+			break;
+		}
+		up(&(slave_image->sem));
+	}
+
+	/* No free image */
+	if (allocated_image == NULL)
+		goto err_image;
+
+	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
+	if (resource == NULL) {
+		printk(KERN_WARNING "Unable to allocate resource structure\n");
+		goto err_alloc;
+	}
+	resource->type = VME_SLAVE;
+	resource->entry = &(allocated_image->list);
+
+	return resource;
+
+err_alloc:
+	/* Unlock image */
+	down(&(slave_image->sem));
+	slave_image->locked = 0;
+	up(&(slave_image->sem));
+err_image:
+err_bus:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_slave_request);
+
+int vme_slave_set (struct vme_resource *resource, int enabled,
+	unsigned long long vme_base, unsigned long long size,
+	dma_addr_t buf_base, vme_address_t aspace, vme_cycle_t cycle)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_slave_resource *image;
+	int retval;
+
+	if (resource->type != VME_SLAVE) {
+		printk("Not a slave resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_slave_resource, list);
+
+	if (bridge->slave_set == NULL) {
+		printk("Function not supported\n");
+		return -ENOSYS;
+	}
+
+	if(!(((image->address_attr & aspace) == aspace) &&
+		((image->cycle_attr & cycle) == cycle))) {
+		printk("Invalid attributes\n");
+		return -EINVAL;
+	}
+
+	retval = vme_check_window(aspace, vme_base, size);
+	if(retval)
+		return retval;
+
+	return bridge->slave_set(image, enabled, vme_base, size, buf_base,
+		aspace, cycle);
+}
+EXPORT_SYMBOL(vme_slave_set);
+
+int vme_slave_get (struct vme_resource *resource, int *enabled,
+	unsigned long long *vme_base, unsigned long long *size,
+	dma_addr_t *buf_base, vme_address_t *aspace, vme_cycle_t *cycle)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_slave_resource *image;
+
+	if (resource->type != VME_SLAVE) {
+		printk("Not a slave resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_slave_resource, list);
+
+	if (bridge->slave_set == NULL) {
+		printk("vme_slave_get not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->slave_get(image, enabled, vme_base, size, buf_base,
+		aspace, cycle);
+}
+EXPORT_SYMBOL(vme_slave_get);
+
+void vme_slave_free(struct vme_resource *resource)
+{
+	struct vme_slave_resource *slave_image;
+
+	if (resource->type != VME_SLAVE) {
+		printk("Not a slave resource\n");
+		return;
+	}
+
+	slave_image = list_entry(resource->entry, struct vme_slave_resource,
+		list);
+	if (slave_image == NULL) {
+		printk("Can't find slave resource\n");
+		return;
+	}
+
+	/* Unlock image */
+	down(&(slave_image->sem));
+	if (slave_image->locked == 0)
+		printk(KERN_ERR "Image is already free\n");
+
+	slave_image->locked = 0;
+	up(&(slave_image->sem));
+
+	/* Free up resource memory */
+	kfree(resource);
+}
+EXPORT_SYMBOL(vme_slave_free);
+
+/*
+ * Request a master image with specific attributes, return some unique
+ * identifier.
+ */
+struct vme_resource * vme_master_request(struct device *dev,
+	vme_address_t address, vme_cycle_t cycle, vme_width_t dwidth)
+{
+	struct vme_bridge *bridge;
+	struct list_head *master_pos = NULL;
+	struct vme_master_resource *allocated_image = NULL;
+	struct vme_master_resource *master_image = NULL;
+	struct vme_resource *resource = NULL;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		goto err_bus;
+	}
+
+	/* Loop through master resources */
+	list_for_each(master_pos, &(bridge->master_resources)) {
+		master_image = list_entry(master_pos,
+			struct vme_master_resource, list);
+
+		if (master_image == NULL) {
+			printk(KERN_WARNING "Registered NULL master resource\n");
+			continue;
+		}
+
+		/* Find an unlocked and compatible image */
+		spin_lock(&(master_image->lock));
+		if(((master_image->address_attr & address) == address) &&
+			((master_image->cycle_attr & cycle) == cycle) &&
+			((master_image->width_attr & dwidth) == dwidth) &&
+			(master_image->locked == 0)) {
+
+			master_image->locked = 1;
+			spin_unlock(&(master_image->lock));
+			allocated_image = master_image;
+			break;
+		}
+		spin_unlock(&(master_image->lock));
+	}
+
+	/* Check to see if we found a resource */
+	if (allocated_image == NULL) {
+		printk(KERN_ERR "Can't find a suitable resource\n");
+		goto err_image;
+	}
+
+	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
+	if (resource == NULL) {
+		printk(KERN_ERR "Unable to allocate resource structure\n");
+		goto err_alloc;
+	}
+	resource->type = VME_MASTER;
+	resource->entry = &(allocated_image->list);
+
+	return resource;
+
+	kfree(resource);
+err_alloc:
+	/* Unlock image */
+	spin_lock(&(master_image->lock));
+	master_image->locked = 0;
+	spin_unlock(&(master_image->lock));
+err_image:
+err_bus:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_master_request);
+
+int vme_master_set (struct vme_resource *resource, int enabled,
+	unsigned long long vme_base, unsigned long long size,
+	vme_address_t aspace, vme_cycle_t cycle, vme_width_t dwidth)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_master_resource *image;
+	int retval;
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_master_resource, list);
+
+	if (bridge->master_set == NULL) {
+		printk("vme_master_set not supported\n");
+		return -EINVAL;
+	}
+
+	if(!(((image->address_attr & aspace) == aspace) &&
+		((image->cycle_attr & cycle) == cycle) &&
+		((image->width_attr & dwidth) == dwidth))) {
+		printk("Invalid attributes\n");
+		return -EINVAL;
+	}
+
+	retval = vme_check_window(aspace, vme_base, size);
+	if(retval)
+		return retval;
+
+	return bridge->master_set(image, enabled, vme_base, size, aspace,
+		cycle, dwidth);
+}
+EXPORT_SYMBOL(vme_master_set);
+
+int vme_master_get (struct vme_resource *resource, int *enabled,
+	unsigned long long *vme_base, unsigned long long *size,
+	vme_address_t *aspace, vme_cycle_t *cycle, vme_width_t *dwidth)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_master_resource *image;
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_master_resource, list);
+
+	if (bridge->master_set == NULL) {
+		printk("vme_master_set not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->master_get(image, enabled, vme_base, size, aspace,
+		cycle, dwidth);
+}
+EXPORT_SYMBOL(vme_master_get);
+
+/*
+ * Read data out of VME space into a buffer.
+ */
+ssize_t vme_master_read (struct vme_resource *resource, void *buf, size_t count,
+	loff_t offset)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_master_resource *image;
+	size_t length;
+
+	if (bridge->master_read == NULL) {
+		printk("Reading from resource not supported\n");
+		return -EINVAL;
+	}
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_master_resource, list);
+
+	length = vme_get_size(resource);
+
+	if (offset > length) {
+		printk("Invalid Offset\n");
+		return -EFAULT;
+	}
+
+	if ((offset + count) > length)
+		count = length - offset;
+
+	return bridge->master_read(image, buf, count, offset);
+
+}
+EXPORT_SYMBOL(vme_master_read);
+
+/*
+ * Write data out to VME space from a buffer.
+ */
+ssize_t vme_master_write (struct vme_resource *resource, void *buf,
+	size_t count, loff_t offset)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_master_resource *image;
+	size_t length;
+
+	if (bridge->master_write == NULL) {
+		printk("Writing to resource not supported\n");
+		return -EINVAL;
+	}
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_master_resource, list);
+
+	length = vme_get_size(resource);
+
+	if (offset > length) {
+		printk("Invalid Offset\n");
+		return -EFAULT;
+	}
+
+	if ((offset + count) > length)
+		count = length - offset;
+
+	return bridge->master_write(image, buf, count, offset);
+}
+EXPORT_SYMBOL(vme_master_write);
+
+/*
+ * Perform RMW cycle to provided location.
+ */
+unsigned int vme_master_rmw (struct vme_resource *resource, unsigned int mask,
+	unsigned int compare, unsigned int swap, loff_t offset)
+{
+	struct vme_bridge *bridge = find_bridge(resource);
+	struct vme_master_resource *image;
+
+	if (bridge->master_rmw == NULL) {
+		printk("Writing to resource not supported\n");
+		return -EINVAL;
+	}
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return -EINVAL;
+	}
+
+	image = list_entry(resource->entry, struct vme_master_resource, list);
+
+	return bridge->master_rmw(image, mask, compare, swap, offset);
+}
+EXPORT_SYMBOL(vme_master_rmw);
+
+void vme_master_free(struct vme_resource *resource)
+{
+	struct vme_master_resource *master_image;
+
+	if (resource->type != VME_MASTER) {
+		printk("Not a master resource\n");
+		return;
+	}
+
+	master_image = list_entry(resource->entry, struct vme_master_resource,
+		list);
+	if (master_image == NULL) {
+		printk("Can't find master resource\n");
+		return;
+	}
+
+	/* Unlock image */
+	spin_lock(&(master_image->lock));
+	if (master_image->locked == 0)
+		printk(KERN_ERR "Image is already free\n");
+
+	master_image->locked = 0;
+	spin_unlock(&(master_image->lock));
+
+	/* Free up resource memory */
+	kfree(resource);
+}
+EXPORT_SYMBOL(vme_master_free);
+
+/*
+ * Request a DMA controller with specific attributes, return some unique
+ * identifier.
+ */
+struct vme_resource *vme_request_dma(struct device *dev)
+{
+	struct vme_bridge *bridge;
+	struct list_head *dma_pos = NULL;
+	struct vme_dma_resource *allocated_ctrlr = NULL;
+	struct vme_dma_resource *dma_ctrlr = NULL;
+	struct vme_resource *resource = NULL;
+
+	/* XXX Not checking resource attributes */
+	printk(KERN_ERR "No VME resource Attribute tests done\n");
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		goto err_bus;
+	}
+
+	/* Loop through DMA resources */
+	list_for_each(dma_pos, &(bridge->dma_resources)) {
+		dma_ctrlr = list_entry(dma_pos,
+			struct vme_dma_resource, list);
+
+		if (dma_ctrlr == NULL) {
+			printk("Registered NULL DMA resource\n");
+			continue;
+		}
+
+		/* Find an unlocked controller */
+		down(&(dma_ctrlr->sem));
+		if(dma_ctrlr->locked == 0) {
+			dma_ctrlr->locked = 1;
+			up(&(dma_ctrlr->sem));
+			allocated_ctrlr = dma_ctrlr;
+			break;
+		}
+		up(&(dma_ctrlr->sem));
+	}
+
+	/* Check to see if we found a resource */
+	if (allocated_ctrlr == NULL)
+		goto err_ctrlr;
+
+	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
+	if (resource == NULL) {
+		printk(KERN_WARNING "Unable to allocate resource structure\n");
+		goto err_alloc;
+	}
+	resource->type = VME_DMA;
+	resource->entry = &(allocated_ctrlr->list);
+
+	return resource;
+
+err_alloc:
+	/* Unlock image */
+	down(&(dma_ctrlr->sem));
+	dma_ctrlr->locked = 0;
+	up(&(dma_ctrlr->sem));
+err_ctrlr:
+err_bus:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_request_dma);
+
+/*
+ * Start new list
+ */
+struct vme_dma_list *vme_new_dma_list(struct vme_resource *resource)
+{
+	struct vme_dma_resource *ctrlr;
+	struct vme_dma_list *dma_list;
+
+	if (resource->type != VME_DMA) {
+		printk("Not a DMA resource\n");
+		return NULL;
+	}
+
+	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);
+
+	dma_list = (struct vme_dma_list *)kmalloc(
+		sizeof(struct vme_dma_list), GFP_KERNEL);
+	if(dma_list == NULL) {
+		printk("Unable to allocate memory for new dma list\n");
+		return NULL;
+	}
+	INIT_LIST_HEAD(&(dma_list->entries));
+	dma_list->parent = ctrlr;
+	init_MUTEX(&(dma_list->sem));
+
+	return dma_list;
+}
+EXPORT_SYMBOL(vme_new_dma_list);
+
+/*
+ * Create "Pattern" type attributes
+ */
+struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern,
+	vme_pattern_t type)
+{
+	struct vme_dma_attr *attributes;
+	struct vme_dma_pattern *pattern_attr;
+
+	attributes = (struct vme_dma_attr *)kmalloc(
+		sizeof(struct vme_dma_attr), GFP_KERNEL);
+	if(attributes == NULL) {
+		printk("Unable to allocate memory for attributes structure\n");
+		goto err_attr;
+	}
+
+	pattern_attr = (struct vme_dma_pattern *)kmalloc(
+		sizeof(struct vme_dma_pattern), GFP_KERNEL);
+	if(pattern_attr == NULL) {
+		printk("Unable to allocate memory for pattern attributes\n");
+		goto err_pat;
+	}
+
+	attributes->type = VME_DMA_PATTERN;
+	attributes->private = (void *)pattern_attr;
+
+	pattern_attr->pattern = pattern;
+	pattern_attr->type = type;
+
+	return attributes;
+
+	kfree(pattern_attr);
+err_pat:
+	kfree(attributes);
+err_attr:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_dma_pattern_attribute);
+
+/*
+ * Create "PCI" type attributes
+ */
+struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t address)
+{
+	struct vme_dma_attr *attributes;
+	struct vme_dma_pci *pci_attr;
+
+	/* XXX Run some sanity checks here */
+
+	attributes = (struct vme_dma_attr *)kmalloc(
+		sizeof(struct vme_dma_attr), GFP_KERNEL);
+	if(attributes == NULL) {
+		printk("Unable to allocate memory for attributes structure\n");
+		goto err_attr;
+	}
+
+	pci_attr = (struct vme_dma_pci *)kmalloc(sizeof(struct vme_dma_pci),
+		GFP_KERNEL);
+	if(pci_attr == NULL) {
+		printk("Unable to allocate memory for pci attributes\n");
+		goto err_pci;
+	}
+
+
+
+	attributes->type = VME_DMA_PCI;
+	attributes->private = (void *)pci_attr;
+
+	pci_attr->address = address;
+
+	return attributes;
+
+	kfree(pci_attr);
+err_pci:
+	kfree(attributes);
+err_attr:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_dma_pci_attribute);
+
+/*
+ * Create "VME" type attributes
+ */
+struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long address,
+	vme_address_t aspace, vme_cycle_t cycle, vme_width_t dwidth)
+{
+	struct vme_dma_attr *attributes;
+	struct vme_dma_vme *vme_attr;
+
+	/* XXX Run some sanity checks here */
+
+	attributes = (struct vme_dma_attr *)kmalloc(
+		sizeof(struct vme_dma_attr), GFP_KERNEL);
+	if(attributes == NULL) {
+		printk("Unable to allocate memory for attributes structure\n");
+		goto err_attr;
+	}
+
+	vme_attr = (struct vme_dma_vme *)kmalloc(sizeof(struct vme_dma_vme),
+		GFP_KERNEL);
+	if(vme_attr == NULL) {
+		printk("Unable to allocate memory for vme attributes\n");
+		goto err_vme;
+	}
+
+	attributes->type = VME_DMA_VME;
+	attributes->private = (void *)vme_attr;
+
+	vme_attr->address = address;
+	vme_attr->aspace = aspace;
+	vme_attr->cycle = cycle;
+	vme_attr->dwidth = dwidth;
+
+	return attributes;
+
+	kfree(vme_attr);
+err_vme:
+	kfree(attributes);
+err_attr:
+	return NULL;
+}
+EXPORT_SYMBOL(vme_dma_vme_attribute);
+
+/*
+ * Free attribute
+ */
+void vme_dma_free_attribute(struct vme_dma_attr *attributes)
+{
+	kfree(attributes->private);
+	kfree(attributes);
+}
+EXPORT_SYMBOL(vme_dma_free_attribute);
+
+int vme_dma_list_add(struct vme_dma_list *list, struct vme_dma_attr *src,
+	struct vme_dma_attr *dest, size_t count)
+{
+	struct vme_bridge *bridge = list->parent->parent;
+	int retval;
+
+	if (bridge->dma_list_add == NULL) {
+		printk("Link List DMA generation not supported\n");
+		return -EINVAL;
+	}
+
+	if (down_trylock(&(list->sem))) {
+		printk("Link List already submitted\n");
+		return -EINVAL;
+	}
+
+	retval = bridge->dma_list_add(list, src, dest, count);
+
+	up(&(list->sem));
+
+	return retval;
+}
+EXPORT_SYMBOL(vme_dma_list_add);
+
+int vme_dma_list_exec(struct vme_dma_list *list)
+{
+	struct vme_bridge *bridge = list->parent->parent;
+	int retval;
+
+	if (bridge->dma_list_exec == NULL) {
+		printk("Link List DMA execution not supported\n");
+		return -EINVAL;
+	}
+
+	down(&(list->sem));
+
+	retval = bridge->dma_list_exec(list);
+
+	up(&(list->sem));
+
+	return retval;
+}
+EXPORT_SYMBOL(vme_dma_list_exec);
+
+int vme_dma_list_free(struct vme_dma_list *list)
+{
+	struct vme_bridge *bridge = list->parent->parent;
+	int retval;
+
+	if (bridge->dma_list_empty == NULL) {
+		printk("Emptying of Link Lists not supported\n");
+		return -EINVAL;
+	}
+
+	if (down_trylock(&(list->sem))) {
+		printk("Link List in use\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Empty out all of the entries from the dma list. We need to go to the
+	 * low level driver as dma entries are driver specific.
+	 */
+	retval = bridge->dma_list_empty(list);
+	if (retval) {
+		printk("Unable to empty link-list entries\n");
+		up(&(list->sem));
+		return retval;
+	}
+	up(&(list->sem));
+	kfree(list);
+
+	return retval;
+}
+EXPORT_SYMBOL(vme_dma_list_free);
+
+int vme_dma_free(struct vme_resource *resource)
+{
+	struct vme_dma_resource *ctrlr;
+
+	if (resource->type != VME_DMA) {
+		printk("Not a DMA resource\n");
+		return -EINVAL;
+	}
+
+	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);
+
+	if (down_trylock(&(ctrlr->sem))) {
+		printk("Resource busy, can't free\n");
+		return -EBUSY;
+	}
+
+	if (!(list_empty(&(ctrlr->pending)) && list_empty(&(ctrlr->running)))) {
+		printk("Resource still processing transfers\n");
+		up(&(ctrlr->sem));
+		return -EBUSY;
+	}
+
+	ctrlr->locked = 0;
+
+	up(&(ctrlr->sem));
+
+	return 0;
+}
+EXPORT_SYMBOL(vme_dma_free);
+
+int vme_request_irq(struct device *dev, int level, int statid,
+	void (*callback)(int level, int vector, void *priv_data),
+	void *priv_data)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if((level < 1) || (level > 7)) {
+		printk(KERN_WARNING "Invalid interrupt level\n");
+		return -EINVAL;
+	}
+
+	if (bridge->request_irq == NULL) {
+		printk("Registering interrupts not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->request_irq(level, statid, callback, priv_data);
+}
+EXPORT_SYMBOL(vme_request_irq);
+
+void vme_free_irq(struct device *dev, int level, int statid)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return;
+	}
+
+	if((level < 1) || (level > 7)) {
+		printk(KERN_WARNING "Invalid interrupt level\n");
+		return;
+	}
+
+	if (bridge->free_irq == NULL) {
+		printk("Freeing interrupts not supported\n");
+		return;
+	}
+
+	bridge->free_irq(level, statid);
+}
+EXPORT_SYMBOL(vme_free_irq);
+
+int vme_generate_irq(struct device *dev, int level, int statid)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if((level < 1) || (level > 7)) {
+		printk(KERN_WARNING "Invalid interrupt level\n");
+		return -EINVAL;
+	}
+
+	if (bridge->generate_irq == NULL) {
+		printk("Interrupt generation not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->generate_irq(level, statid);
+}
+EXPORT_SYMBOL(vme_generate_irq);
+
+int vme_lm_set(struct device *dev, unsigned long long lm_base, vme_address_t aspace,
+	vme_cycle_t cycle)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if (bridge->lm_set == NULL) {
+		printk("vme_lm_set not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->lm_set(lm_base, aspace, cycle);
+}
+EXPORT_SYMBOL(vme_lm_set);
+
+int vme_lm_get(struct device *dev, unsigned long long *lm_base, vme_address_t *aspace,
+	vme_cycle_t *cycle)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if (bridge->lm_get == NULL) {
+		printk("vme_lm_get not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->lm_get(lm_base, aspace, cycle);
+}
+EXPORT_SYMBOL(vme_lm_get);
+
+int vme_lm_attach(struct device *dev, int monitor, void (*callback)(int))
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if (bridge->lm_attach == NULL) {
+		printk("vme_lm_attach not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->lm_attach(monitor, callback);
+}
+EXPORT_SYMBOL(vme_lm_attach);
+
+int vme_lm_detach(struct device *dev, int monitor)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(dev);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if (bridge->lm_detach == NULL) {
+		printk("vme_lm_detach not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->lm_detach(monitor);
+}
+EXPORT_SYMBOL(vme_lm_detach);
+
+int vme_slot_get(struct device *bus)
+{
+	struct vme_bridge *bridge;
+
+	bridge = dev_to_bridge(bus);
+	if (bridge == NULL) {
+		printk(KERN_ERR "Can't find VME bus\n");
+		return -EINVAL;
+	}
+
+	if (bridge->slot_get == NULL) {
+		printk("vme_slot_get not supported\n");
+		return -EINVAL;
+	}
+
+	return bridge->slot_get();
+}
+EXPORT_SYMBOL(vme_slot_get);
+
+
+/* - Bridge Registration --------------------------------------------------- */
+
+static int vme_alloc_bus_num(void)
+{
+	int i;
+
+	down(&vme_bus_num_sem);
+	for (i = 0; i < sizeof(vme_bus_numbers) * 8; i++) {
+		if (((vme_bus_numbers >> i) & 0x1) == 0) {
+			vme_bus_numbers |= (0x1 << i);
+			break;
+		}
+	}
+	up(&vme_bus_num_sem);
+
+	return i;
+}
+
+static void vme_free_bus_num(int bus)
+{
+	down(&vme_bus_num_sem);
+	vme_bus_numbers |= ~(0x1 << bus);
+	up(&vme_bus_num_sem);
+}
+
+int vme_register_bridge (struct vme_bridge *bridge)
+{
+	struct device *dev;
+	int retval;
+	int i;
+
+	bridge->num = vme_alloc_bus_num();
+
+	/* This creates 32 vme "slot" devices. This equates to a slot for each
+	 * ID available in a system conforming to the ANSI/VITA 1-1994
+	 * specification.
+	 */
+	for (i = 0; i < VME_SLOTS_MAX; i++) {
+		dev = &(bridge->dev[i]);
+		memset(dev, 0, sizeof(struct device));
+
+		dev->parent = bridge->parent;
+		dev->bus = &(vme_bus_type);
+		/*
+		 * We save a pointer to the bridge in platform_data so that we
+		 * can get to it later. We keep driver_data for use by the
+		 * driver that binds against the slot
+		 */
+		dev->platform_data = bridge;
+		dev_set_name(dev, "vme-%x.%x", bridge->num, i + 1);
+
+		retval = device_register(dev);
+		if(retval)
+			goto err_reg;
+	}
+
+	return retval;
+
+	i = VME_SLOTS_MAX;
+err_reg:
+	while (i > -1) {
+		dev = &(bridge->dev[i]);
+		device_unregister(dev);
+	}
+	vme_free_bus_num(bridge->num);
+	return retval;
+}
+EXPORT_SYMBOL(vme_register_bridge);
+
+void vme_unregister_bridge (struct vme_bridge *bridge)
+{
+	int i;
+	struct device *dev;
+
+
+	for (i = 0; i < VME_SLOTS_MAX; i++) {
+		dev = &(bridge->dev[i]);
+		device_unregister(dev);
+	}
+	vme_free_bus_num(bridge->num);
+}
+EXPORT_SYMBOL(vme_unregister_bridge);
+
+
+/* - Driver Registration --------------------------------------------------- */
+
+int vme_register_driver (struct vme_driver *drv)
+{
+	drv->driver.name = drv->name;
+	drv->driver.bus = &vme_bus_type;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL(vme_register_driver);
+
+void vme_unregister_driver (struct vme_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL(vme_unregister_driver);
+
+/* - Bus Registration ------------------------------------------------------ */
+
+int vme_calc_slot(struct device *dev)
+{
+	struct vme_bridge *bridge;
+	int num;
+
+	bridge = dev_to_bridge(dev);
+
+	/* Determine slot number */
+	num = 0;
+	while(num < VME_SLOTS_MAX) {
+		if(&(bridge->dev[num]) == dev) {
+			break;
+		}
+		num++;
+	}
+	if (num == VME_SLOTS_MAX) {
+		dev_err(dev, "Failed to identify slot\n");
+		num = 0;
+		goto err_dev;
+	}
+	num++;
+
+err_dev:
+	return num;
+}
+
+static struct vme_driver *dev_to_vme_driver(struct device *dev)
+{
+	if(dev->driver == NULL)
+		printk("Bugger dev->driver is NULL\n");
+
+	return container_of(dev->driver, struct vme_driver, driver);
+}
+
+static int vme_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct vme_bridge *bridge;
+	struct vme_driver *driver;
+	int i, num;
+
+	bridge = dev_to_bridge(dev);
+	driver = container_of(drv, struct vme_driver, driver);
+
+	num = vme_calc_slot(dev);
+	if (!num)
+		goto err_dev;
+
+	if (driver->bind_table == NULL) {
+		dev_err(dev, "Bind table NULL\n");
+		goto err_table;
+	}
+
+	i = 0;
+	while((driver->bind_table[i].bus != 0) ||
+		(driver->bind_table[i].slot != 0)) {
+
+		if ((bridge->num == driver->bind_table[i].bus) &&
+			(num == driver->bind_table[i].slot))
+			return 1;
+		i++;
+	}
+
+err_dev:
+err_table:
+	return 0;
+}
+
+static int vme_bus_probe(struct device *dev)
+{
+	struct vme_bridge *bridge;
+	struct vme_driver *driver;
+	int retval = -ENODEV;
+
+	driver = dev_to_vme_driver(dev);
+	bridge = dev_to_bridge(dev);
+
+	if(driver->probe != NULL) {
+		retval = driver->probe(dev, bridge->num, vme_calc_slot(dev));
+	}
+
+	return retval;
+}
+
+static int vme_bus_remove(struct device *dev)
+{
+	struct vme_bridge *bridge;
+	struct vme_driver *driver;
+	int retval = -ENODEV;
+
+	driver = dev_to_vme_driver(dev);
+	bridge = dev_to_bridge(dev);
+
+	if(driver->remove != NULL) {
+		retval = driver->remove(dev, bridge->num, vme_calc_slot(dev));
+	}
+
+	return retval;
+}
+
+struct bus_type vme_bus_type = {
+	.name = "vme",
+	.match = vme_bus_match,
+	.probe = vme_bus_probe,
+	.remove = vme_bus_remove,
+};
+EXPORT_SYMBOL(vme_bus_type);
+
+static int __init vme_init (void)
+{
+	return bus_register(&vme_bus_type);
+}
+
+static void __exit vme_exit (void)
+{
+	bus_unregister(&vme_bus_type);
+}
+
+MODULE_DESCRIPTION("VME bridge driver framework");
+MODULE_AUTHOR("Martyn Welch <[email protected]");
+MODULE_LICENSE("GPL");
+
+module_init(vme_init);
+module_exit(vme_exit);

drivers/staging/vme/vme.h new file +153 -0

@@ -0,0 +1,153 @@
+#ifndef _VME_H_
+#define _VME_H_
+
+/* Resource Type */
+enum vme_resource_type {
+	VME_MASTER,
+	VME_SLAVE,
+	VME_DMA
+};
+
+/* VME Address Spaces */
+typedef u32 vme_address_t;
+#define VME_A16		0x1
+#define VME_A24		0x2
+#define	VME_A32		0x4
+#define VME_A64		0x8
+#define VME_CRCSR	0x10
+#define VME_USER1	0x20
+#define VME_USER2	0x40
+#define VME_USER3	0x80
+#define VME_USER4	0x100
+
+#define VME_A16_MAX	0x10000ULL
+#define VME_A24_MAX	0x1000000ULL
+#define VME_A32_MAX	0x100000000ULL
+#define VME_A64_MAX	0x10000000000000000ULL
+#define VME_CRCSR_MAX	0x1000000ULL
+
+
+/* VME Cycle Types */
+typedef u32 vme_cycle_t;
+#define VME_SCT		0x1
+#define VME_BLT		0x2
+#define VME_MBLT	0x4
+#define VME_2eVME	0x8
+#define VME_2eSST	0x10
+#define VME_2eSSTB	0x20
+
+#define VME_2eSST160	0x100
+#define VME_2eSST267	0x200
+#define VME_2eSST320	0x400
+
+#define	VME_SUPER	0x1000
+#define	VME_USER	0x2000
+#define	VME_PROG	0x4000
+#define	VME_DATA	0x8000
+
+/* VME Data Widths */
+typedef u32 vme_width_t;
+#define VME_D8		0x1
+#define VME_D16		0x2
+#define VME_D32		0x4
+#define VME_D64		0x8
+
+/* Arbitration Scheduling Modes */
+typedef u32 vme_arbitration_t;
+#define VME_R_ROBIN_MODE	0x1
+#define VME_PRIORITY_MODE	0x2
+
+typedef u32 vme_dma_t;
+#define VME_DMA_PATTERN			(1<<0)
+#define VME_DMA_PCI			(1<<1)
+#define VME_DMA_VME			(1<<2)
+
+typedef u32 vme_pattern_t;
+#define VME_DMA_PATTERN_BYTE		(1<<0)
+#define VME_DMA_PATTERN_WORD		(1<<1)
+#define VME_DMA_PATTERN_INCREMENT	(1<<2)
+
+struct vme_dma_attr {
+	vme_dma_t type;
+	void *private;
+};
+
+struct vme_resource {
+	enum vme_resource_type type;
+	struct list_head *entry;
+};
+
+extern struct bus_type vme_bus_type;
+
+struct vme_device_id {
+	int bus;
+	int slot;
+};
+
+struct vme_driver {
+	struct list_head node;
+	char *name;
+	const struct vme_device_id *bind_table;
+	int (*probe)  (struct device *, int, int);
+	int (*remove) (struct device *, int, int);
+	void (*shutdown) (void);
+	struct device_driver    driver;
+};
+
+void * vme_alloc_consistent(struct vme_resource *, size_t, dma_addr_t *);
+void vme_free_consistent(struct vme_resource *, size_t,  void *,
+	dma_addr_t);
+
+size_t vme_get_size(struct vme_resource *);
+
+struct vme_resource * vme_slave_request(struct device *, vme_address_t, vme_cycle_t);
+int vme_slave_set (struct vme_resource *, int, unsigned long long,
+	unsigned long long, dma_addr_t, vme_address_t, vme_cycle_t);
+int vme_slave_get (struct vme_resource *, int *, unsigned long long *,
+	unsigned long long *, dma_addr_t *, vme_address_t *, vme_cycle_t *);
+void vme_slave_free(struct vme_resource *);
+
+struct vme_resource * vme_master_request(struct device *, vme_address_t, vme_cycle_t,
+	vme_width_t);
+int vme_master_set (struct vme_resource *, int, unsigned long long,
+	unsigned long long, vme_address_t, vme_cycle_t, vme_width_t);
+int vme_master_get (struct vme_resource *, int *, unsigned long long *,
+	unsigned long long *, vme_address_t *, vme_cycle_t *, vme_width_t *);
+ssize_t vme_master_read(struct vme_resource *, void *, size_t, loff_t);
+ssize_t vme_master_write(struct vme_resource *, void *, size_t, loff_t);
+unsigned int vme_master_rmw (struct vme_resource *, unsigned int, unsigned int,
+	unsigned int, loff_t);
+void vme_master_free(struct vme_resource *);
+
+struct vme_resource *vme_request_dma(struct device *);
+struct vme_dma_list *vme_new_dma_list(struct vme_resource *);
+struct vme_dma_attr *vme_dma_pattern_attribute(u32, vme_pattern_t);
+struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t);
+struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long, vme_address_t,
+	vme_cycle_t, vme_width_t);
+void vme_dma_free_attribute(struct vme_dma_attr *);
+int vme_dma_list_add(struct vme_dma_list *, struct vme_dma_attr *,
+	struct vme_dma_attr *, size_t);
+int vme_dma_list_exec(struct vme_dma_list *);
+int vme_dma_list_free(struct vme_dma_list *);
+int vme_dma_free(struct vme_resource *);
+
+int vme_request_irq(struct device *, int, int,
+	void (*callback)(int, int, void *), void *);
+void vme_free_irq(struct device *, int, int);
+int vme_generate_irq(struct device *, int, int);
+
+int vme_lm_set(struct device *, unsigned long long, vme_address_t, vme_cycle_t);
+int vme_lm_get(struct device *, unsigned long long *, vme_address_t *,
+	vme_cycle_t *);
+int vme_lm_attach(struct device *, int, void (*callback)(int));
+int vme_lm_detach(struct device *, int);
+
+int vme_slot_get(struct device *);
+
+int vme_register_driver (struct vme_driver *);
+void vme_unregister_driver (struct vme_driver *);
+
+
+#endif /* _VME_H_ */
+

A few comments after a quick glance, will need to dig deeper though:
- semaphores? isn't it screaming for mutexes?

- some function signatures (get_whatever) pass too many pointers; it's rather ugly. Passing a pointer to an appropriate struct seems a better solution.

- vme_alloc_consistent looks pretty fishy; why don't you pass that responsibility to the specific master? There you obviously know if you're bridging over PCI or whatever. Or even better; why is this needed at all?

- Please explain me what all the DMA functions do; are they meant to be used by master or slaves?

Have a look at the interface for slaves we've got for our tsi148 driver, available at:
http://repo.or.cz/w/tsi148vmebridge.git

/* API for new drivers */
extern int vme_request_irq(unsigned int, int (*)(void *),

                           void *, const char *);

extern int vme_free_irq(unsigned int );
extern int vme_generate_interrupt(int, int, signed long); extern struct vme_mapping* find_vme_mapping_from_addr(unsigned); extern int vme_get_window_attr(struct vme_mapping *); extern int vme_create_window(struct vme_mapping *); extern int vme_destroy_window(int);
extern int vme_find_mapping(struct vme_mapping *, int); extern int vme_release_mapping(struct vme_mapping *, int); extern int vme_do_dma(struct vme_dma *);
extern int vme_bus_error_check(int);

That's pretty thin and it covers our slaves' needs. Do you see anything missing there?

For masters there's no interface there because it was the master's driver who directly provided these calls to slaves. I had it in my to-do list to split that from the tsi148, in the same fashion as you've done with this work.

- Note above the interrupt handler; simply needs the cookie. Also, shouldn't your vme_request_irq() just require the IRQ vector?

- I'd like to see the whole picture, or 'vertical slice', i.e. the bus interface + a master + a slave driver. How would the slave's driver get the addresses and sizes of the mappings, interrupt lines, etc. for each of the devices it controls? For the time being we quickly hacked an xml-based scheme to get this info upon installation, but it's clearly not suitable for mainline.

Will probably have more comments when I get some time for further inspection.

Quoted 1 line · Emilio G. Cota

- semaphores? isn't it screaming for mutexes?

The semaphores are initialized in mutex mode.

Quoted 4 lines

- some function signatures (get_whatever) pass too many pointers; it's rather ugly. Passing a pointer to an appropriate struct seems a better solution.

When implementing these functions it seemed like a simpler option to pass the parameters rather than defining yet another structure and using it for a single call. If the *_get functions are changed then the *_set functions should also be changed for consistency. I'm not overly bothered either way - if the consensus is that a structure would be better then we can go with a structure.

Quoted 5 lines

- vme_alloc_consistent looks pretty fishy; why don't you pass that responsibility to the specific master? There you obviously know if you're bridging over PCI or whatever. Or even better; why is this needed at all?

In the model I have chosen it is up to the VME device driver to create buffers rather than the VME bridge drivers. After all it is the device drivers for the specific hardware found on the VME bus that knows what it is going to do with these buffers. This method is provided as a helper. It ensures that a VME device driver (not to be confused with the VME bridge driver) is able to allocate a buffer suitable for utilizing the DMA engines found in the bridge or indeed to be mapped onto VME though a slave window without explicitly knowing which VME bridge is being used.

Master windows don't require a contiguous buffer, are you referring to something else when you say master?

Quoted 3 lines

- Please explain me what all the DMA functions do; are they meant to be used by master or slaves?

The TODO file (drivers/staging/vme/TODO) contains a description of the current API including the DMA functions, does that provide enough of a description?

Quoted 7 lines

Have a look at the interface for slaves we've got for our tsi148 driver, available at:
http://repo.or.cz/w/tsi148vmebridge.git

/* API for new drivers */
extern int vme_request_irq(unsigned int, int (*)(void *),

                           void *, const char *);

Quoted 5 lines

extern int vme_bus_error_check(int);

That's pretty thin and it covers our slaves' needs. Do you see anything missing there?

This interface, especially struct vme_mapping seems to have been written solely for the tsi-148 bridge. The API I have defined aims to provide a consistent API across multiple VME bridges. Whilst this API clearly works for you with the tsi-148 I am unsure how suitable it will be for other bridge chips.

The API I have proposed is designed to support more than just the tsi148 chipset. Have you thought about how the above API will be supported on other VME bridges?

Quoted 8 lines

For masters there's no interface there because it was the master's driver who directly provided these calls to slaves. I had it in my to-do list to split that from the tsi148, in the same fashion as you've done with this work.

- Note above the interrupt handler; simply needs the cookie. Also, shouldn't your vme_request_irq() just require the IRQ vector?

No. I believe that you are using the term IRQ vector where we would use the term status ID, the value which is returned from an IACK cycle. Your interrupt handling code assigns a single interrupt handler to all interrupt levels, purely using the interrupt vector/status ID to determine which interrupt handler will be used. This adds an artificial limitation and would not work in some instances that we have seen. Our framework provides the ability to attach an interrupt handler to each combination of IRQ level and Status ID/vector.

Quoted 8 lines

- I'd like to see the whole picture, or 'vertical slice', i.e. the bus interface + a master + a slave driver. How would the slave's driver get the addresses and sizes of the mappings, interrupt lines, etc. for each of the devices it controls? For the time being we quickly hacked an xml-based scheme to get this info upon installation, but it's clearly not suitable for mainline.

I have written a test driver for a very old slave card we had lying around. In that case we used module parameters to determine the location of the device on the bus (it used a fixed VME address space). In this instance the interrupt level and ID could be configured in the registers available in the VME address space, hence I added module parameters to allow these to be configured. In this respect configuration of VME devices is very similar to ISA devices - neither of the buses has supported discovery mechanism from the outset and thus old cards. I therefore implemented a mechanism similar to how I believe ISA approaches this.

The framework that I have proposed aims to provide a consistent API to manage allowing the resources provided by the VME bridges to be managed in as a consistent a manner as possible. I believe it is up to the device drivers for the devices found on the VME bus to determine the best way to configure this as it is not provided by the VME specifications.

For using the VME bus for communication between two SBCs, I think we could use the CRCSR space to provide some information about the resources used on each board for say, a virtual network driver like the rapidIO subsystem provides. Possibly using the "device tree" stuff used on PowerPC, Blackfin and Sparc archs (I believe) for passing device layout between the firmware and kernel at boot.

Sure, np,

Martyn

I've had a closer look; it seems to me that most of it is unnecessary; there's no show those lists to a driver. I'd just provide a single 'do_dma(attributes)' call that sleeps until it's done (or similar).

Quoted 4 lines · Emilio G. Cota

I've had a closer look; it seems to me that most of it is unnecessary; there's no show those lists to a driver. I'd just provide a single 'do_dma(attributes)' call that sleeps until it's done (or similar).

s/there's no show/there's no point in showing/

Basically the driver simply shouldn't care about these DMA lists. It just wants to get the work done, no matter how.

E.

If the driver writer wants a "single shot" effect, there's little overhead in creating a one item link-list and executing it. However, without support for this mode the author is stuck with single shot transfers. If the author wants to perform scatter gather type transfers, without this functionality in the API - which is supported by all the bridges I have seen - he won't be able to easily avail himself of this functionality and get "work done".

Quoted 2 lines · Martyn Welch

If the driver writer wants a "single shot" effect, there's little overhead in creating a one item link-list and executing it. However, without support for this mode the author is stuck with single shot transfers. If the author wants to perform scatter gather type transfers, without this functionality in the API - which is supported by all the bridges I have seen - he won't be able to easily avail himself of this functionality and get "work done".

Again, he (the driver writer) should know *nothing* about that.

As for the scatter-gather case, what should happen is:

User: hey, there's a buffer I want to transfer. here's
a pointer and size

VME layer: ok, passing it to the bridge
VME bridge: I know I'm over PCI, so I'll get the pages
from memory and map the sg list over PCI, and then will tell the bridge to perform from there.

That's just a particular example, but for the user (read driver writer) it's much simpler this way. Doesn't need to know about lists or whatever.

E.

Quoted 4 lines · Emilio G. Cota

Again, he (the driver writer) should know *nothing* about that.

As for the scatter-gather case, what should happen is:

Quoted 2 lines

User: hey, there's a buffer I want to transfer. here's
a pointer and size

Buffer where? On VME or PCI, where are you transferring it to? The API I have will allow scattered locations on VME to be copied to PCI and visa-versa, scattered locations on PCI to be copied to VME and visa-versa. Even scattered locations on VME to scattered locations on PCI with a bit of effort.

Quoted 6 lines · Martyn Welch

Quoted 2 lines · Emilio G. Cota

- semaphores? isn't it screaming for mutexes?

The semaphores are initialized in mutex mode.

I know, but then please use mutexes.

Quoted 7 lines

Quoted 5 lines

- some function signatures (get_whatever) pass too many pointers; it's rather ugly. Passing a pointer to an appropriate struct seems a better solution.

When implementing these functions it seemed like a simpler option to pass the parameters rather than defining yet another structure and using it for a single call. If the *_get functions are changed then the *_set functions should also be changed for consistency. I'm not overly bothered either way - if the consensus is that a structure would be better then we can go with a structure.

Yeh, In my opinion a structure there would be prettier. However let's put this off a bit, I'm currently re-working this a bit.

Quoted 8 lines

Quoted 6 lines

- vme_alloc_consistent looks pretty fishy; why don't you pass that responsibility to the specific master? There you obviously know if you're bridging over PCI or whatever. Or even better; why is this needed at all?

In the model I have chosen it is up to the VME device driver to create buffers rather than the VME bridge drivers. After all it is the device drivers for the specific hardware found on the VME bus that knows what it is going to do with these buffers. This method is provided as a helper. It ensures that a VME device driver (not to be confused with the VME bridge driver) is able to allocate a buffer suitable for utilizing the DMA engines found in the bridge or indeed to be mapped onto VME though a slave window without explicitly knowing which VME bridge is being used.

hmm I see. The way you provide coherent DMA mappings for VME is through providing coherent (consistent) mappings for PCI, and then mapping the VME space onto those. I haven't tested if this works, but sounds reasonable.

Quoted 2 lines

Master windows don't require a contiguous buffer, are you referring to something else when you say master?

I was thinking of the hypothetical case where you'd have a bridge not over PCI; but anyway since quite a few things seem tied to PCI this is fine.

Quoted 4 lines

Quoted 4 lines

- Please explain me what all the DMA functions do; are they meant to be used by master or slaves?

Quoted 2 lines

The TODO file (drivers/staging/vme/TODO) contains a description of the current API including the DMA functions, does that provide enough of a description?

I've had a closer look; it seems to me that most of it is unnecessary; there's no show those lists to a driver. I'd just provide a single 'do_dma(attributes)' call that sleeps until it's done (or similar).

Quoted 8 lines

Quoted 8 lines

Have a look at the interface for slaves we've got for our tsi148 driver, available at:
http://repo.or.cz/w/tsi148vmebridge.git

/* API for new drivers */
extern int vme_request_irq(unsigned int, int (*)(void *),

                           void *, const char *);

[snip]

Quoted 10 lines

Quoted 6 lines

extern int vme_bus_error_check(int);

That's pretty thin and it covers our slaves' needs. Do you see anything missing there?

This interface, especially struct vme_mapping seems to have been written solely for the tsi-148 bridge. The API I have defined aims to provide a consistent API across multiple VME bridges. Whilst this API clearly works for you with the tsi-148 I am unsure how suitable it will be for other bridge chips.

The API I have proposed is designed to support more than just the tsi148 chipset. Have you thought about how the above API will be supported on other VME bridges?

We only have access to tsi148 chips. Since apparently there aren't many bridges around, I think is saner to just provide an interface that works well with the devices we have access to (i.e. tsi148 and Tundra Universe in your case), and when new chips come along, we simply modify the interface as needed. Of course this doesn't mean we shouldn't try to make it generic, but within reason.

Quoted 11 lines

Quoted 9 lines

For masters there's no interface there because it was the master's driver who directly provided these calls to slaves. I had it in my to-do list to split that from the tsi148, in the same fashion as you've done with this work.

- Note above the interrupt handler; simply needs the cookie. Also, shouldn't your vme_request_irq() just require the IRQ vector?

No. I believe that you are using the term IRQ vector where we would use the term status ID, the value which is returned from an IACK cycle. Your interrupt handling code assigns a single interrupt handler to all interrupt levels, purely using the interrupt vector/status ID to determine which interrupt handler will be used. This adds an artificial limitation and would not work in some instances that we have seen. Our framework provides the ability to attach an interrupt handler to each combination of IRQ level and Status ID/vector.

Fair enough. For sanity we tend not to share IRQ vectors among different modules, but yes, the interface should know about this.

Quoted 9 lines

Quoted 9 lines

- I'd like to see the whole picture, or 'vertical slice', i.e. the bus interface + a master + a slave driver. How would the slave's driver get the addresses and sizes of the mappings, interrupt lines, etc. for each of the devices it controls? For the time being we quickly hacked an xml-based scheme to get this info upon installation, but it's clearly not suitable for mainline.

Quoted 4 lines

I have written a test driver for a very old slave card we had lying around. In that case we used module parameters to determine the location of the device on the bus (it used a fixed VME address space). In this instance the interrupt level and ID could be configured in the registers available in the VME address space, hence I added module parameters to allow these to be configured. In this respect configuration of VME devices is very similar to ISA devices - neither of the buses has supported discovery mechanism from the outset and thus old cards. I therefore implemented a mechanism similar to how I believe ISA approaches this.

The framework that I have proposed aims to provide a consistent API to manage allowing the resources provided by the VME bridges to be managed in as a consistent a manner as possible. I believe it is up to the device drivers for the devices found on the VME bus to determine the best way to configure this as it is not provided by the VME specifications.

The problem is how to manage several (say 10) devices that have to be controlled with the same driver; passing parameters upon loading the driver's module doesn't seem to scale beyond one device..

At the moment I see no clean way of doing this; right now we're doing it through an IOCTL, copying from user-space a tree that describes the devices to install, namely mappings and IRQs for each of them.

Greg, any ideas on how to deal with this?

Quoted 2 lines

For using the VME bus for communication between two SBCs, I think we could use the CRCSR space to provide some information about the resources used on each board for say, a virtual network driver like the rapidIO subsystem provides. Possibly using the "device tree" stuff used on PowerPC, Blackfin and Sparc archs (I believe) for passing device layout between the firmware and kernel at boot.

hmm I don't see how we could implement this common consistent view of the bus in a way that could work with every bridge. For the time being I'd defer this and simply pass that responsibility to user-space.

Quoted 4 lines

Sure, np,

Martyn

Thanks,
E.

Quoted 6 lines · Emilio G. Cota

Quoted 4 lines · Martyn Welch

Quoted 2 lines · Emilio G. Cota

- semaphores? isn't it screaming for mutexes?

Quoted 6 lines

Quoted 2 lines

The semaphores are initialized in mutex mode.

I know, but then please use mutexes.

I'm clearly missing something here - can you provide me with an example?

That's one reason for the helper function. If VME bridges are added which sit of on other buses then vme_alloc_consistent can be extended to support this without requiring VME device drivers to be altered to reflect the fact that pci_alloc_consistent might not work for all VME bridges.

The DMA controller in the tsi-148 can do PCI to PCI; PCI to VME; VME to PCI; VME to VME; Patterns to VME and Patterns to PCI transfers. How do you specify all those options without providing a structure where over 50% of the fields aren't used for any given transfer?

Every bridge I have seen is capable of link-list execution. The API provides the ability to do scatter-gather style DMA transfers, this could be used as part of a "zero-copy" type driver for high speed VME capture devices. How would you support the link-list execution with a single call?

I was also looking at the ability to queue DMA transfers if the controller was currently busy - if the consensus is that this is overkill I will happily remove this.

I implemented it using param array, I agree that the arguments might get quite long with 10 devices, especially if multiple parameters are required, but I don't see why it shouldn't work.

Quoted 2 lines · Martyn Welch

That's one reason for the helper function. If VME bridges are added which sit of on other buses then vme_alloc_consistent can be extended to support this without requiring VME device drivers to be altered to reflect the fact that pci_alloc_consistent might not work for all VME bridges.

But it corresponds to the bridge's code (not to the generic layer) to know whether the bridge sits on top of PCI or not; hence my comment.

Quoted 2 lines

The DMA controller in the tsi-148 can do PCI to PCI; PCI to VME; VME to PCI; VME to VME; Patterns to VME and Patterns to PCI transfers. How do you specify all those options without providing a structure where over 50% of the fields aren't used for any given transfer?

I think a struct where not _every_ field is *always* used is fine. However requiring your drivers to know about what your bridge looks like is a mistake; just give them something thin that doesn't assume anything about what's behind it, and if it's not supported, return an appropriate error message.

Quoted 2 lines

Every bridge I have seen is capable of link-list execution. The API provides the ability to do scatter-gather style DMA transfers, this could be used as part of a "zero-copy" type driver for high speed VME capture devices. How would you support the link-list execution with a single call?

Let me say it again: "Drivers should know *nothing* about the underlying bridge".
They should work with *any* bridge; or do we care about the PCI bridge we're plug our PCI device on when writing a driver for it?

Quoted 2 lines

I was also looking at the ability to queue DMA transfers if the controller was currently busy - if the consensus is that this is overkill I will happily remove this.

AFAICT the tsi148 has several DMA channels; in our driver we just try to find a free channel to proceed with the transfer; if there aren't any then we return EBUSY.

Drawing an analogy with current 'streaming DMA' transfers, we're told we should check whether they failed or not, so I think trying to be too clever here it's not worth it.

Quoted 4 lines

I implemented it using param array, I agree that the arguments might get quite long with 10 devices, especially if multiple parameters are required, but I don't see why it shouldn't work.

The fact that 'it works' doesn't make it less ugly or messy. When referring to code, these two words usually mean "there's a better way"; so let's just find it.

E.

Again: what part of the API I have defined forces the driver to know about the underlying bridge?

Quoted 2 lines · Martyn Welch

Again: what part of the API I have defined forces the driver to know about the underlying bridge?

Let me answer with another question, maybe we get to understand each other this way:

Could you please explain me what happens when 17 different drivers want to control 17 different devices, each on a different slot, same address modifier, only 1MB per device? Apply if necessary to the tsi148 bridge.

NB1. Any given driver knows nothing about the other devices on the crate; each driver only knows about the address, am and size of the mapping for the device it controls--user-space provide this info on a per-driver basis.

NB2. The mapping offsets configured through the cards' pins match the information passed from user space to each of the cards.

Cheers,
E.

Not the same question, but I'd agree - that would probably break the current model I have proposed. *However*, providing a resource management layer as you have proposed above the basic resource management my API provides would resolve that without added complexity in the bridge drivers themselves.

Yes. If I understand you correctly, your saying that management of the devices in the VME address space is a system configuration issue.

Quoted 2 lines · Martyn Welch

Not the same question, but I'd agree - that would probably break the current model I have proposed. *However*, providing a resource management layer as you have proposed above the basic resource management my API provides would resolve that without added complexity in the bridge drivers themselves.

It wouldn't break it, the model simply couldn't give you more than 8 windows-->8 devices.

I think it should be the bridge the one that manages its own resources, not someone else.

I'm coding a layer that works this way, we'll see how it looks.

Quoted 2 lines

Yes. If I understand you correctly, your saying that management of the devices in the VME address space is a system configuration issue.

It obviously is. We cannot impose the users where they should plug their devices or which pins on the boards they should tweak. They build their crates --> they tell the kernel about them.

Quoted 3 lines

It wouldn't break it, the model simply couldn't give you more than 8 windows-->8 devices.

Unless the devices we the same and the driver reused one window.

Quoted 6 lines · Martyn Welch

Quoted 4 lines

It wouldn't break it, the model simply couldn't give you more than 8 windows-->8 devices.

Unless the devices we the same and the driver reused one window.

No, we agreed on that devices should know *nothing* about windows.

E.

need for both approaches. It may be more efficient for a driver to use and move 1 window to position it's self over the registers of each of a number of compatible devices as required.

There is a further device situated between the two.

Quoted 2 lines

How do you now protect the registers of this device from

Quoted 1 line

accidental/malicous/buggy behaviour from your board, since

this region of the VME bus is now enabled for transfers in the PCI IO Mem space?

Quoted 9 lines · Martyn Welch

There is a further device situated between the two.

Quoted 4 lines

How do you now protect the registers of this device from

Quoted 2 lines

accidental/malicous/buggy behaviour from your board, since

this region of the VME bus is now enabled for transfers in the PCI IO Mem space?

The kernel is not designed to work with buggy hardware--that would be insane, we've got more than enough dealing with our own bugs. However when there's no other solution (e.g. hardware can't be fixed for whatever reason), fixes on a per-case basis may be applied.

E.

Apart from : not mapping regions of the VME bus that you are not using.

Quoted 2 lines · Martyn Welch

Apart from : not mapping regions of the VME bus that you are not using.

The tsi148 mappings have to be on 64k boundaries, so yes, it happens that sometimes you map a bit more than what you need. But there's no way to get around that; it's a hardware thing so we just accept it.

E.

For using the VME bus for communication between two SBCs, I think we could use the CRCSR space to provide some information about the resources used on each board for say, a virtual network driver like the rapidIO subsystem provides. Possibly using the "device tree" stuff used on PowerPC, Blackfin and Sparc archs (I believe) for passing device layout between the firmware and kernel at boot.

Quoted 7 lines · Martyn Welch

For using the VME bus for communication between two SBCs, I think we could use the CRCSR space to provide some information about the resources used on each board for say, a virtual network driver like the rapidIO subsystem provides. Possibly using the "device tree" stuff used on PowerPC, Blackfin and Sparc archs (I believe) for passing device layout between the firmware and kernel at boot.

Blackfin doesnt use device trees and there are no plans to do so -mike

A few comments after a quick glance, will need to dig deeper though:
- semaphores? isn't it screaming for mutexes?

It's checking the wrong functions; fix it.

Signed-off-by Emilio G. Cota <[email protected]>

---
 drivers/staging/vme/vme.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

drivers/staging/vme/vme.c +2 -2

index 8ee1192..ed2eeb0 100644
@@ -338,7 +338,7 @@ int vme_slave_get (struct vme_resource *resource, int *enabled,
 
 	image = list_entry(resource->entry, struct vme_slave_resource, list);
 
-	if (bridge->slave_set == NULL) {
+	if (bridge->slave_get == NULL) {
 		printk("vme_slave_get not supported\n");
 		return -EINVAL;
 	}

@@ -499,7 +499,7 @@ int vme_master_get (struct vme_resource *resource, int *enabled,
 
 	image = list_entry(resource->entry, struct vme_master_resource, list);
 
-	if (bridge->master_set == NULL) {
+	if (bridge->master_get == NULL) {
 		printk("vme_master_set not supported\n");
 		return -EINVAL;
 	}

From: Martyn Welch <[email protected]>

Adds a VME userspace access driver

Signed-off-by Martyn Welch <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/staging/vme/Kconfig            |    4 
 drivers/staging/vme/Makefile           |    2 
 drivers/staging/vme/devices/Kconfig    |    8 
 drivers/staging/vme/devices/Makefile   |    5 
 drivers/staging/vme/devices/vme_user.c |  771 +++++++++++++++++++++++++++++++++
 drivers/staging/vme/devices/vme_user.h |   43 +
 6 files changed, 830 insertions(+), 3 deletions(-)

drivers/staging/vme/devices/Kconfig new file +8 -0

@@ -0,0 +1,8 @@
+comment "VME Device Drivers"
+
+config VME_USER
+	tristate "VME user space access driver"
+	help
+	  If you say Y here you want to be able to access a limited number of
+	  VME windows in a manner at least semi-compatible with the interface
+	  provided with the original driver at http://vmelinux.org/.

drivers/staging/vme/devices/Makefile new file +5 -0

@@ -0,0 +1,5 @@
+#
+# Makefile for the VME device drivers.
+#
+
+obj-$(CONFIG_VME_USER)		+= vme_user.o

drivers/staging/vme/devices/vme_user.c new file +771 -0

@@ -0,0 +1,771 @@
+/*
+ * VMEbus User access driver
+ *
+ * Author: Martyn Welch <[email protected]>
+ * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * Based on work by:
+ *   Tom Armistead and Ajit Prem
+ *     Copyright 2004 Motorola Inc.
+ *
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/pci.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include "../vme.h"
+#include "vme_user.h"
+
+/* Currently Documentation/devices.txt defines the following for VME:
+ *
+ * 221 char	VME bus
+ * 		  0 = /dev/bus/vme/m0		First master image
+ * 		  1 = /dev/bus/vme/m1		Second master image
+ * 		  2 = /dev/bus/vme/m2		Third master image
+ * 		  3 = /dev/bus/vme/m3		Fourth master image
+ * 		  4 = /dev/bus/vme/s0		First slave image
+ * 		  5 = /dev/bus/vme/s1		Second slave image
+ * 		  6 = /dev/bus/vme/s2		Third slave image
+ * 		  7 = /dev/bus/vme/s3		Fourth slave image
+ * 		  8 = /dev/bus/vme/ctl		Control
+ *
+ * 		It is expected that all VME bus drivers will use the
+ * 		same interface.  For interface documentation see
+ * 		http://www.vmelinux.org/.
+ *
+ * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
+ * even support the tsi148 chipset (which has 8 master and 8 slave windows).
+ * We'll run with this or now as far as possible, however it probably makes
+ * sense to get rid of the old mappings and just do everything dynamically.
+ *
+ * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
+ * defined above and try to support at least some of the interface from
+ * http://www.vmelinux.org/ as an alternative drive can be written providing a
+ * saner interface later.
+ */
+#define VME_MAJOR	221	/* VME Major Device Number */
+#define VME_DEVS	9	/* Number of dev entries */
+
+#define MASTER_MINOR	0
+#define MASTER_MAX	3
+#define SLAVE_MINOR	4
+#define SLAVE_MAX	7
+#define CONTROL_MINOR	8
+
+#define PCI_BUF_SIZE  0x20000	/* Size of one slave image buffer */
+
+/*
+ * Structure to handle image related parameters.
+ */
+typedef struct {
+	void __iomem *kern_buf;	/* Buffer address in kernel space */
+	dma_addr_t pci_buf;	/* Buffer address in PCI address space */
+	unsigned long long size_buf;	/* Buffer size */
+	struct semaphore sem;	/* Semaphore for locking image */
+	struct device *device;	/* Sysfs device */
+	struct vme_resource *resource;	/* VME resource */
+	int users;		/* Number of current users */
+} image_desc_t;
+static image_desc_t image[VME_DEVS];
+
+typedef struct {
+	unsigned long reads;
+	unsigned long writes;
+	unsigned long ioctls;
+	unsigned long irqs;
+	unsigned long berrs;
+	unsigned long dmaErrors;
+	unsigned long timeouts;
+	unsigned long external;
+} driver_stats_t;
+static driver_stats_t statistics;
+
+struct cdev *vme_user_cdev;		/* Character device */
+struct class *vme_user_sysfs_class;	/* Sysfs class */
+struct device *vme_user_bridge;		/* Pointer to the bridge device */
+
+static char driver_name[] = "vme_user";
+
+static const int type[VME_DEVS] = {	MASTER_MINOR,	MASTER_MINOR,
+					MASTER_MINOR,	MASTER_MINOR,
+					SLAVE_MINOR,	SLAVE_MINOR,
+					SLAVE_MINOR,	SLAVE_MINOR,
+					CONTROL_MINOR
+				};
+
+
+static int vme_user_open(struct inode *, struct file *);
+static int vme_user_release(struct inode *, struct file *);
+static ssize_t vme_user_read(struct file *, char *, size_t, loff_t *);
+static ssize_t vme_user_write(struct file *, const char *, size_t, loff_t *);
+static loff_t vme_user_llseek(struct file *, loff_t, int);
+static int vme_user_ioctl(struct inode *, struct file *, unsigned int,
+	unsigned long);
+
+static int __init vme_user_probe(struct device *dev);
+
+static struct file_operations vme_user_fops = {
+        .open = vme_user_open,
+        .release = vme_user_release,
+        .read = vme_user_read,
+        .write = vme_user_write,
+        .llseek = vme_user_llseek,
+        .ioctl = vme_user_ioctl,
+};
+
+
+/*
+ * Reset all the statistic counters
+ */
+static void reset_counters(void)
+{
+        statistics.reads = 0;
+        statistics.writes = 0;
+        statistics.ioctls = 0;
+        statistics.irqs = 0;
+        statistics.berrs = 0;
+        statistics.dmaErrors = 0;
+        statistics.timeouts = 0;
+}
+
+void lmcall(int monitor)
+{
+	printk("Caught Location Monitor %d access\n", monitor);
+}
+
+static void tests(void)
+{
+	struct vme_resource *dma_res;
+	struct vme_dma_list *dma_list;
+	struct vme_dma_attr *pattern_attr, *vme_attr;
+
+	int retval;
+	unsigned int data;
+
+	printk("Running VME DMA test\n");
+	dma_res = vme_request_dma(vme_user_bridge);
+	dma_list = vme_new_dma_list(dma_res);
+	pattern_attr = vme_dma_pattern_attribute(0x0,
+		VME_DMA_PATTERN_WORD |
+			VME_DMA_PATTERN_INCREMENT);
+	vme_attr = vme_dma_vme_attribute(0x10000, VME_A32,
+		VME_SCT, VME_D32);
+	retval = vme_dma_list_add(dma_list, pattern_attr,
+		vme_attr, 0x10000);
+#if 0
+	vme_dma_free_attribute(vme_attr);
+	vme_attr = vme_dma_vme_attribute(0x20000, VME_A32,
+		VME_SCT, VME_D32);
+	retval = vme_dma_list_add(dma_list, pattern_attr,
+		vme_attr, 0x10000);
+#endif
+	retval = vme_dma_list_exec(dma_list);
+	vme_dma_free_attribute(pattern_attr);
+	vme_dma_free_attribute(vme_attr);
+	vme_dma_list_free(dma_list);
+#if 0
+	printk("Generating a VME interrupt\n");
+	vme_generate_irq(dma_res, 0x3, 0xaa);
+	printk("Interrupt returned\n");
+#endif
+	vme_dma_free(dma_res);
+
+	/* Attempt RMW */
+	data = vme_master_rmw(image[0].resource, 0x80000000, 0x00000000,
+		0x80000000, 0);
+	printk("RMW returned 0x%8.8x\n", data);
+
+
+	/* Location Monitor */
+	printk("vme_lm_set:%d\n", vme_lm_set(vme_user_bridge, 0x60000, VME_A32, VME_SCT | VME_USER | VME_DATA));
+	printk("vme_lm_attach:%d\n", vme_lm_attach(vme_user_bridge, 0, lmcall));
+
+	printk("Board in VME slot:%d\n", vme_slot_get(vme_user_bridge));
+}
+
+static int vme_user_open(struct inode *inode, struct file *file)
+{
+	int err;
+	unsigned int minor = MINOR(inode->i_rdev);
+
+	down(&image[minor].sem);
+	/* Only allow device to be opened if a resource is allocated */
+	if (image[minor].resource == NULL) {
+		printk(KERN_ERR "No resources allocated for device\n");
+		err = -EINVAL;
+		goto err_res;
+	}
+
+	/* Increment user count */
+	image[minor].users++;
+
+	up(&image[minor].sem);
+
+	return 0;
+
+err_res:
+	up(&image[minor].sem);
+
+	return err;
+}
+
+static int vme_user_release(struct inode *inode, struct file *file)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+
+	down(&image[minor].sem);
+
+	/* Decrement user count */
+	image[minor].users--;
+
+	up(&image[minor].sem);
+
+	return 0;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go VME -> buffer -> user space. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly into the user space buffers.
+ */
+static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
+	loff_t *ppos)
+{
+	ssize_t retval;
+	ssize_t copied = 0;
+
+	if (count <= image[minor].size_buf) {
+		/* We copy to kernel buffer */
+		copied = vme_master_read(image[minor].resource,
+			image[minor].kern_buf, count, *ppos);
+		if (copied < 0) {
+			return (int)copied;
+		}
+
+		retval = __copy_to_user(buf, image[minor].kern_buf,
+			(unsigned long)copied);
+		if (retval != 0) {
+			copied = (copied - retval);
+			printk("User copy failed\n");
+			return -EINVAL;
+		}
+
+	} else {
+		/* XXX Need to write this */
+		printk("Currently don't support large transfers\n");
+		/* Map in pages from userspace */
+
+		/* Call vme_master_read to do the transfer */
+		return -EINVAL;
+	}
+
+	return copied;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go user space -> buffer -> VME. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly from the user space buffers out to VME.
+ */
+static ssize_t resource_from_user(unsigned int minor, const char *buf,
+	size_t count, loff_t *ppos)
+{
+	ssize_t retval;
+	ssize_t copied = 0;
+
+	if (count <= image[minor].size_buf) {
+		retval = __copy_from_user(image[minor].kern_buf, buf,
+			(unsigned long)count);
+		if (retval != 0)
+			copied = (copied - retval);
+		else
+			copied = count;
+
+		copied = vme_master_write(image[minor].resource,
+			image[minor].kern_buf, copied, *ppos);
+	} else {
+		/* XXX Need to write this */
+		printk("Currently don't support large transfers\n");
+		/* Map in pages from userspace */
+
+		/* Call vme_master_write to do the transfer */
+		return -EINVAL;
+	}
+
+	return copied;
+}
+
+static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
+	size_t count, loff_t *ppos)
+{
+	void __iomem *image_ptr;
+	ssize_t retval;
+
+	image_ptr = image[minor].kern_buf + *ppos;
+
+	retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
+	if (retval != 0) {
+		retval = (count - retval);
+		printk(KERN_WARNING "Partial copy to userspace\n");
+	} else
+		retval = count;
+
+	/* Return number of bytes successfully read */
+	return retval;
+}
+
+static ssize_t buffer_from_user(unsigned int minor, const char *buf,
+	size_t count, loff_t *ppos)
+{
+	void __iomem *image_ptr;
+	size_t retval;
+
+	image_ptr = image[minor].kern_buf + *ppos;
+
+	retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
+	if (retval != 0) {
+		retval = (count - retval);
+		printk(KERN_WARNING "Partial copy to userspace\n");
+	} else
+		retval = count;
+
+	/* Return number of bytes successfully read */
+	return retval;
+}
+
+static ssize_t vme_user_read(struct file *file, char *buf, size_t count,
+			loff_t * ppos)
+{
+	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+	ssize_t retval;
+	size_t image_size;
+	size_t okcount;
+
+	down(&image[minor].sem);
+
+	/* XXX Do we *really* want this helper - we can use vme_*_get ? */
+	image_size = vme_get_size(image[minor].resource);
+
+	/* Ensure we are starting at a valid location */
+	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+		up(&image[minor].sem);
+		return 0;
+	}
+
+	/* Ensure not reading past end of the image */
+	if (*ppos + count > image_size)
+		okcount = image_size - *ppos;
+	else
+		okcount = count;
+
+	switch (type[minor]){
+	case MASTER_MINOR:
+		retval = resource_to_user(minor, buf, okcount, ppos);
+		break;
+	case SLAVE_MINOR:
+		retval = buffer_to_user(minor, buf, okcount, ppos);
+		break;
+	default:
+		retval = -EINVAL;
+	}
+
+	up(&image[minor].sem);
+
+	if (retval > 0)
+		*ppos += retval;
+
+	return retval;
+}
+
+static ssize_t vme_user_write(struct file *file, const char *buf, size_t count,
+			 loff_t *ppos)
+{
+	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+	ssize_t retval;
+	size_t image_size;
+	size_t okcount;
+
+	down(&image[minor].sem);
+
+	image_size = vme_get_size(image[minor].resource);
+
+	/* Ensure we are starting at a valid location */
+	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+		up(&image[minor].sem);
+		return 0;
+	}
+
+	/* Ensure not reading past end of the image */
+	if (*ppos + count > image_size)
+		okcount = image_size - *ppos;
+	else
+		okcount = count;
+
+	switch (type[minor]){
+	case MASTER_MINOR:
+		retval = resource_from_user(minor, buf, okcount, ppos);
+		break;
+	case SLAVE_MINOR:
+		retval = buffer_from_user(minor, buf, okcount, ppos);
+		break;
+	default:
+		retval = -EINVAL;
+	}
+
+	up(&image[minor].sem);
+
+	if (retval > 0)
+		*ppos += retval;
+
+	return retval;
+}
+
+static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
+{
+	printk(KERN_ERR "Llseek currently incomplete\n");
+	return -EINVAL;
+}
+
+static int vme_user_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+#if 0
+	int ret_val;
+#endif
+	unsigned long copyRet;
+	vme_slave_t slave;
+
+	statistics.ioctls++;
+	switch (type[minor]) {
+	case CONTROL_MINOR:
+		break;
+	case MASTER_MINOR:
+		break;
+	case SLAVE_MINOR:
+		switch (cmd) {
+		case VME_SET_SLAVE:
+
+			copyRet = copy_from_user(&slave, (char *)arg,
+				sizeof(slave));
+			if (copyRet != 0) {
+				printk(KERN_WARNING "Partial copy from "
+					"userspace\n");
+				return -EFAULT;
+			}
+
+			return vme_slave_set(image[minor].resource,
+				slave.enable, slave.vme_addr, slave.size,
+				image[minor].pci_buf, slave.aspace,
+				slave.cycle);
+
+			break;
+#if 0
+		case VME_GET_SLAVE:
+			vme_slave_t slave;
+
+			ret_val = vme_slave_get(minor, &iRegs);
+
+			copyRet = copy_to_user((char *)arg, &slave,
+				sizeof(slave));
+			if (copyRet != 0) {
+				printk(KERN_WARNING "Partial copy to "
+					"userspace\n");
+				return -EFAULT;
+			}
+
+			return ret_val;
+			break;
+#endif
+		}
+		break;
+	}
+
+	return -EINVAL;
+}
+
+
+/*
+ * Unallocate a previously allocated buffer
+ */
+static void buf_unalloc (int num)
+{
+	if (image[num].kern_buf) {
+#ifdef VME_DEBUG
+		printk(KERN_DEBUG "UniverseII:Releasing buffer at %p\n",
+			image[num].pci_buf);
+#endif
+
+		vme_free_consistent(image[num].resource, image[num].size_buf,
+			image[num].kern_buf, image[num].pci_buf);
+
+		image[num].kern_buf = NULL;
+		image[num].pci_buf = 0;
+		image[num].size_buf = 0;
+
+#ifdef VME_DEBUG
+	} else {
+		printk(KERN_DEBUG "UniverseII: Buffer not allocated\n");
+#endif
+	}
+}
+
+static struct vme_driver vme_user_driver = {
+        .name = driver_name,
+        .probe = vme_user_probe,
+};
+
+
+/*
+ * In this simple access driver, the old behaviour is being preserved as much
+ * as practical. We will therefore reserve the buffers and request the images
+ * here so that we don't have to do it later.
+ */
+static int __init vme_bridge_init(void)
+{
+	int retval;
+	printk(KERN_INFO "VME User Space Access Driver\n");
+	printk("vme_user_driver:%p\n", &vme_user_driver);
+	retval = vme_register_driver(&vme_user_driver);
+	printk("vme_register_driver returned %d\n", retval);
+	return retval;
+}
+
+/*
+ * This structure gets passed a device, this should be the device created at
+ * registration.
+ */
+static int __init vme_user_probe(struct device *dev)
+{
+	int i, err;
+	char name[8];
+
+	printk("Running vme_user_probe()\n");
+
+	/* Pointer to the bridge device */
+	vme_user_bridge = dev;
+
+	/* Initialise descriptors */
+	for (i = 0; i < VME_DEVS; i++) {
+		image[i].kern_buf = NULL;
+		image[i].pci_buf = 0;
+		init_MUTEX(&(image[i].sem));
+		image[i].device = NULL;
+		image[i].resource = NULL;
+		image[i].users = 0;
+	}
+
+	/* Initialise statistics counters */
+	reset_counters();
+
+	/* Assign major and minor numbers for the driver */
+	err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
+		driver_name);
+	if (err) {
+		printk(KERN_WARNING "%s: Error getting Major Number %d for "
+		"driver.\n", driver_name, VME_MAJOR);
+		goto err_region;
+	}
+
+	/* Register the driver as a char device */
+	vme_user_cdev = cdev_alloc();
+	vme_user_cdev->ops = &vme_user_fops;
+	vme_user_cdev->owner = THIS_MODULE;
+	err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
+	if (err) {
+		printk(KERN_WARNING "%s: cdev_all failed\n", driver_name);
+		goto err_char;
+	}
+
+	/* Request slave resources and allocate buffers (128kB wide) */
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		/* XXX Need to properly request attributes */
+		image[i].resource = vme_slave_request(vme_user_bridge,
+			VME_A16, VME_SCT);
+		if (image[i].resource == NULL) {
+			printk(KERN_WARNING "Unable to allocate slave "
+				"resource\n");
+			goto err_buf;
+		}
+		image[i].size_buf = PCI_BUF_SIZE;
+		image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+			image[i].size_buf, &(image[i].pci_buf));
+		if (image[i].kern_buf == NULL) {
+			printk(KERN_WARNING "Unable to allocate memory for "
+				"buffer\n");
+			image[i].pci_buf = 0;
+			vme_slave_free(image[i].resource);
+			err = -ENOMEM;
+			goto err_buf;
+		}
+	}
+
+	/*
+	 * Request master resources allocate page sized buffers for small
+	 * reads and writes
+	 */
+	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+		/* XXX Need to properly request attributes */
+		image[i].resource = vme_master_request(vme_user_bridge,
+			VME_A32, VME_SCT, VME_D32);
+		if (image[i].resource == NULL) {
+			printk(KERN_WARNING "Unable to allocate master "
+				"resource\n");
+			goto err_buf;
+		}
+		image[i].size_buf = PAGE_SIZE;
+		image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+			image[i].size_buf, &(image[i].pci_buf));
+		if (image[i].kern_buf == NULL) {
+			printk(KERN_WARNING "Unable to allocate memory for "
+				"buffer\n");
+			image[i].pci_buf = 0;
+			vme_master_free(image[i].resource);
+			err = -ENOMEM;
+			goto err_buf;
+		}
+	}
+
+	/* Setup some debug windows */
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		err = vme_slave_set(image[i].resource, 1, 0x4000*(i-4),
+			0x4000, image[i].pci_buf, VME_A16,
+			VME_SCT | VME_SUPER | VME_USER | VME_PROG | VME_DATA);
+		if (err != 0) {
+			printk(KERN_WARNING "Failed to configure window\n");
+			goto err_buf;
+		}
+	}
+	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+		err = vme_master_set(image[i].resource, 1,
+			(0x10000 + (0x10000*i)), 0x10000,
+			VME_A32, VME_SCT | VME_USER | VME_DATA, VME_D32);
+		if (err != 0) {
+			printk(KERN_WARNING "Failed to configure window\n");
+			goto err_buf;
+		}
+	}
+
+	/* Create sysfs entries - on udev systems this creates the dev files */
+	vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
+	if (IS_ERR(vme_user_sysfs_class)) {
+		printk(KERN_ERR "Error creating vme_user class.\n");
+		err = PTR_ERR(vme_user_sysfs_class);
+		goto err_class;
+	}
+
+	/* Add sysfs Entries */
+	for (i=0; i<VME_DEVS; i++) {
+		switch (type[i]) {
+		case MASTER_MINOR:
+			sprintf(name,"bus/vme/m%%d");
+			break;
+		case CONTROL_MINOR:
+			sprintf(name,"bus/vme/ctl");
+			break;
+		case SLAVE_MINOR:
+			sprintf(name,"bus/vme/s%%d");
+			break;
+		default:
+			err = -EINVAL;
+			goto err_sysfs;
+			break;
+		}
+
+		image[i].device =
+			device_create(vme_user_sysfs_class, NULL,
+				MKDEV(VME_MAJOR, i), NULL, name,
+				(type[i] == SLAVE_MINOR)? i - (MASTER_MAX + 1) : i);
+		if (IS_ERR(image[i].device)) {
+			printk("%s: Error creating sysfs device\n",
+				driver_name);
+			err = PTR_ERR(image[i].device);
+			goto err_sysfs;
+		}
+	}
+
+	/* XXX Run tests */
+	/*
+	tests();
+	*/
+
+	return 0;
+
+	/* Ensure counter set correcty to destroy all sysfs devices */
+	i = VME_DEVS;
+err_sysfs:
+	while (i > 0){
+		i--;
+		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+	}
+	class_destroy(vme_user_sysfs_class);
+
+	/* Ensure counter set correcty to unalloc all slave buffers */
+	i = SLAVE_MAX + 1;
+err_buf:
+	while (i > SLAVE_MINOR){
+		i--;
+		vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
+		vme_slave_free(image[i].resource);
+		buf_unalloc(i);
+	}
+err_class:
+	cdev_del(vme_user_cdev);
+err_char:
+	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+err_region:
+	return err;
+}
+
+static void __exit vme_bridge_exit(void)
+{
+	int i;
+
+	/* Remove sysfs Entries */
+	for(i=0; i<VME_DEVS; i++) {
+		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+	}
+	class_destroy(vme_user_sysfs_class);
+
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		buf_unalloc(i);
+	}
+
+	/* Unregister device driver */
+	cdev_del(vme_user_cdev);
+
+	/* Unregiser the major and minor device numbers */
+	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+}
+
+MODULE_DESCRIPTION("VME User Space Access Driver");
+MODULE_AUTHOR("Martyn Welch <[email protected]");
+MODULE_LICENSE("GPL");
+
+module_init(vme_bridge_init);
+module_exit(vme_bridge_exit);

drivers/staging/vme/devices/vme_user.h new file +43 -0

@@ -0,0 +1,43 @@
+
+/*
+ * VMEbus Master Window Configuration Structure
+ */
+typedef struct {
+	char enable;			/* State of Window */
+	unsigned long long vme_addr;	/* Starting Address on the VMEbus */
+	unsigned long long size;	/* Window Size */
+	vme_address_t aspace;		/* Address Space */
+	vme_cycle_t cycle;		/* Cycle properties */
+	vme_width_t dwidth;		/* Maximum Data Width */
+#if 0
+	char prefetchEnable;		/* Prefetch Read Enable State */
+	int prefetchSize;		/* Prefetch Read Size (Cache Lines) */
+	char wrPostEnable;		/* Write Post State */
+#endif
+} vme_master_t;
+
+
+/*
+ * IOCTL Commands and structures
+ */
+
+/* Magic number for use in ioctls */
+#define VME_IOC_MAGIC 0xAE
+
+
+/* VMEbus Slave Window Configuration Structure */
+typedef struct {
+	char enable;			/* State of Window */
+	unsigned long long vme_addr;	/* Starting Address on the VMEbus */
+	unsigned long long size;	/* Window Size */
+	vme_address_t aspace;		/* Address Space */
+	vme_cycle_t cycle;		/* Cycle properties */
+#if 0
+	char wrPostEnable;		/* Write Post State */
+	char rmwLock;			/* Lock PCI during RMW Cycles */
+	char data64BitCapable;		/* non-VMEbus capable of 64-bit Data */
+#endif
+} vme_slave_t;
+
+#define VME_SET_SLAVE _IOW(VME_IOC_MAGIC, 10, vme_slave_t)
+

drivers/staging/vme/Kconfig +2 -2

@@ -11,7 +11,7 @@ menuconfig VME
 if VME
 
 #source "drivers/staging/vme/bridges/Kconfig"
-#
-#source "drivers/staging/vme/devices/Kconfig"
+
+source "drivers/staging/vme/devices/Kconfig"
 
 endif # VME

drivers/staging/vme/Makefile +1 -1

@@ -4,4 +4,4 @@
 obj-$(CONFIG_VME)		+= vme.o
 
 #obj-y				+= bridges/
-#obj-y				+= devices/
+obj-y				+= devices/

I remember we had a look at the vmelinux interface, but it really was so limited that we decided to get rid of it altogether. Do you really think it's worth bringing it back to life? Since it's never been merged into the kernel, why don't we just get it right this time and forget about it?

Instead of using that we implemented a heretic IOCTL-based interface for user-space; at least with it you could create a driver (with no interrupt support) for a device in user-space. We actually don't use it, but well, just to get inspiration, here it goes:

/**
* \name Window management ioctl numbers
*/
/** Get a physical window attributes */
#define VME_IOCTL_GET_WINDOW_ATTR _IOWR('V', 0, struct
vme_mapping)
/** Create a physical window */
#define VME_IOCTL_CREATE_WINDOW _IOW( 'V', 1, struct
vme_mapping)
/** Destroy a physical window */
#define VME_IOCTL_DESTROY_WINDOW _IOW( 'V', 2, int)
/** Create a mapping over a physical window */
#define VME_IOCTL_FIND_MAPPING _IOWR('V', 3, struct
vme_mapping)
/** Remove a mapping */
#define VME_IOCTL_RELEASE_MAPPING _IOW( 'V', 4, struct
vme_mapping)
/** Get the create on find failed flag */
#define VME_IOCTL_GET_CREATE_ON_FIND_FAIL _IOR( 'V', 5, unsigned
int)
/** Set the create on find failed flag */
#define VME_IOCTL_SET_CREATE_ON_FIND_FAIL _IOW( 'V', 6, unsigned
int)
/** Get the destroy on remove flag */
#define VME_IOCTL_GET_DESTROY_ON_REMOVE _IOR( 'V', 7, unsigned int) /** Set the destroy on remove flag */
#define VME_IOCTL_SET_DESTROY_ON_REMOVE _IOW( 'V', 8, unsigned int) /** Get bus error status */
#define VME_IOCTL_GET_BUS_ERROR _IOR( 'V', 9, unsigned int)
/** Start a DMA transfer */
#define VME_IOCTL_START_DMA _IOWR('V', 10, struct vme_dma)

[ grab the code from here: http://repo.or.cz/w/tsi148vmebridge.git .
Please note there's some backwards-compatible crap for old user-space LynxOS code, called CES. Ignore it. ]

By the way, please try to be consistent with naming, e.g. I see window, then see "image", and I have to think hard to see whether they mean the same or not.. err, do they?

E.

(I'll leave this here because of added Cc)

Quoted 877 lines · Greg K-H

From: Martyn Welch <[email protected]>

Adds a VME userspace access driver

Signed-off-by Martyn Welch <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/staging/vme/Kconfig            |    4 
 drivers/staging/vme/Makefile           |    2 
 drivers/staging/vme/devices/Kconfig    |    8 
 drivers/staging/vme/devices/Makefile   |    5 
 drivers/staging/vme/devices/vme_user.c |  771 +++++++++++++++++++++++++++++++++
 drivers/staging/vme/devices/vme_user.h |   43 +
 6 files changed, 830 insertions(+), 3 deletions(-)

drivers/staging/vme/devices/Kconfig new file +8 -0

@@ -0,0 +1,8 @@
+comment "VME Device Drivers"
+
+config VME_USER
+	tristate "VME user space access driver"
+	help
+	  If you say Y here you want to be able to access a limited number of
+	  VME windows in a manner at least semi-compatible with the interface
+	  provided with the original driver at http://vmelinux.org/.

drivers/staging/vme/devices/Makefile new file +5 -0

@@ -0,0 +1,5 @@
+#
+# Makefile for the VME device drivers.
+#
+
+obj-$(CONFIG_VME_USER)		+= vme_user.o

drivers/staging/vme/devices/vme_user.c new file +771 -0

@@ -0,0 +1,771 @@
+/*
+ * VMEbus User access driver
+ *
+ * Author: Martyn Welch <[email protected]>
+ * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * Based on work by:
+ *   Tom Armistead and Ajit Prem
+ *     Copyright 2004 Motorola Inc.
+ *
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/pci.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include "../vme.h"
+#include "vme_user.h"
+
+/* Currently Documentation/devices.txt defines the following for VME:
+ *
+ * 221 char	VME bus
+ * 		  0 = /dev/bus/vme/m0		First master image
+ * 		  1 = /dev/bus/vme/m1		Second master image
+ * 		  2 = /dev/bus/vme/m2		Third master image
+ * 		  3 = /dev/bus/vme/m3		Fourth master image
+ * 		  4 = /dev/bus/vme/s0		First slave image
+ * 		  5 = /dev/bus/vme/s1		Second slave image
+ * 		  6 = /dev/bus/vme/s2		Third slave image
+ * 		  7 = /dev/bus/vme/s3		Fourth slave image
+ * 		  8 = /dev/bus/vme/ctl		Control
+ *
+ * 		It is expected that all VME bus drivers will use the
+ * 		same interface.  For interface documentation see
+ * 		http://www.vmelinux.org/.
+ *
+ * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
+ * even support the tsi148 chipset (which has 8 master and 8 slave windows).
+ * We'll run with this or now as far as possible, however it probably makes
+ * sense to get rid of the old mappings and just do everything dynamically.
+ *
+ * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
+ * defined above and try to support at least some of the interface from
+ * http://www.vmelinux.org/ as an alternative drive can be written providing a
+ * saner interface later.
+ */
+#define VME_MAJOR	221	/* VME Major Device Number */
+#define VME_DEVS	9	/* Number of dev entries */
+
+#define MASTER_MINOR	0
+#define MASTER_MAX	3
+#define SLAVE_MINOR	4
+#define SLAVE_MAX	7
+#define CONTROL_MINOR	8
+
+#define PCI_BUF_SIZE  0x20000	/* Size of one slave image buffer */
+
+/*
+ * Structure to handle image related parameters.
+ */
+typedef struct {
+	void __iomem *kern_buf;	/* Buffer address in kernel space */
+	dma_addr_t pci_buf;	/* Buffer address in PCI address space */
+	unsigned long long size_buf;	/* Buffer size */
+	struct semaphore sem;	/* Semaphore for locking image */
+	struct device *device;	/* Sysfs device */
+	struct vme_resource *resource;	/* VME resource */
+	int users;		/* Number of current users */
+} image_desc_t;
+static image_desc_t image[VME_DEVS];
+
+typedef struct {
+	unsigned long reads;
+	unsigned long writes;
+	unsigned long ioctls;
+	unsigned long irqs;
+	unsigned long berrs;
+	unsigned long dmaErrors;
+	unsigned long timeouts;
+	unsigned long external;
+} driver_stats_t;
+static driver_stats_t statistics;
+
+struct cdev *vme_user_cdev;		/* Character device */
+struct class *vme_user_sysfs_class;	/* Sysfs class */
+struct device *vme_user_bridge;		/* Pointer to the bridge device */
+
+static char driver_name[] = "vme_user";
+
+static const int type[VME_DEVS] = {	MASTER_MINOR,	MASTER_MINOR,
+					MASTER_MINOR,	MASTER_MINOR,
+					SLAVE_MINOR,	SLAVE_MINOR,
+					SLAVE_MINOR,	SLAVE_MINOR,
+					CONTROL_MINOR
+				};
+
+
+static int vme_user_open(struct inode *, struct file *);
+static int vme_user_release(struct inode *, struct file *);
+static ssize_t vme_user_read(struct file *, char *, size_t, loff_t *);
+static ssize_t vme_user_write(struct file *, const char *, size_t, loff_t *);
+static loff_t vme_user_llseek(struct file *, loff_t, int);
+static int vme_user_ioctl(struct inode *, struct file *, unsigned int,
+	unsigned long);
+
+static int __init vme_user_probe(struct device *dev);
+
+static struct file_operations vme_user_fops = {
+        .open = vme_user_open,
+        .release = vme_user_release,
+        .read = vme_user_read,
+        .write = vme_user_write,
+        .llseek = vme_user_llseek,
+        .ioctl = vme_user_ioctl,
+};
+
+
+/*
+ * Reset all the statistic counters
+ */
+static void reset_counters(void)
+{
+        statistics.reads = 0;
+        statistics.writes = 0;
+        statistics.ioctls = 0;
+        statistics.irqs = 0;
+        statistics.berrs = 0;
+        statistics.dmaErrors = 0;
+        statistics.timeouts = 0;
+}
+
+void lmcall(int monitor)
+{
+	printk("Caught Location Monitor %d access\n", monitor);
+}
+
+static void tests(void)
+{
+	struct vme_resource *dma_res;
+	struct vme_dma_list *dma_list;
+	struct vme_dma_attr *pattern_attr, *vme_attr;
+
+	int retval;
+	unsigned int data;
+
+	printk("Running VME DMA test\n");
+	dma_res = vme_request_dma(vme_user_bridge);
+	dma_list = vme_new_dma_list(dma_res);
+	pattern_attr = vme_dma_pattern_attribute(0x0,
+		VME_DMA_PATTERN_WORD |
+			VME_DMA_PATTERN_INCREMENT);
+	vme_attr = vme_dma_vme_attribute(0x10000, VME_A32,
+		VME_SCT, VME_D32);
+	retval = vme_dma_list_add(dma_list, pattern_attr,
+		vme_attr, 0x10000);
+#if 0
+	vme_dma_free_attribute(vme_attr);
+	vme_attr = vme_dma_vme_attribute(0x20000, VME_A32,
+		VME_SCT, VME_D32);
+	retval = vme_dma_list_add(dma_list, pattern_attr,
+		vme_attr, 0x10000);
+#endif
+	retval = vme_dma_list_exec(dma_list);
+	vme_dma_free_attribute(pattern_attr);
+	vme_dma_free_attribute(vme_attr);
+	vme_dma_list_free(dma_list);
+#if 0
+	printk("Generating a VME interrupt\n");
+	vme_generate_irq(dma_res, 0x3, 0xaa);
+	printk("Interrupt returned\n");
+#endif
+	vme_dma_free(dma_res);
+
+	/* Attempt RMW */
+	data = vme_master_rmw(image[0].resource, 0x80000000, 0x00000000,
+		0x80000000, 0);
+	printk("RMW returned 0x%8.8x\n", data);
+
+
+	/* Location Monitor */
+	printk("vme_lm_set:%d\n", vme_lm_set(vme_user_bridge, 0x60000, VME_A32, VME_SCT | VME_USER | VME_DATA));
+	printk("vme_lm_attach:%d\n", vme_lm_attach(vme_user_bridge, 0, lmcall));
+
+	printk("Board in VME slot:%d\n", vme_slot_get(vme_user_bridge));
+}
+
+static int vme_user_open(struct inode *inode, struct file *file)
+{
+	int err;
+	unsigned int minor = MINOR(inode->i_rdev);
+
+	down(&image[minor].sem);
+	/* Only allow device to be opened if a resource is allocated */
+	if (image[minor].resource == NULL) {
+		printk(KERN_ERR "No resources allocated for device\n");
+		err = -EINVAL;
+		goto err_res;
+	}
+
+	/* Increment user count */
+	image[minor].users++;
+
+	up(&image[minor].sem);
+
+	return 0;
+
+err_res:
+	up(&image[minor].sem);
+
+	return err;
+}
+
+static int vme_user_release(struct inode *inode, struct file *file)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+
+	down(&image[minor].sem);
+
+	/* Decrement user count */
+	image[minor].users--;
+
+	up(&image[minor].sem);
+
+	return 0;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go VME -> buffer -> user space. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly into the user space buffers.
+ */
+static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
+	loff_t *ppos)
+{
+	ssize_t retval;
+	ssize_t copied = 0;
+
+	if (count <= image[minor].size_buf) {
+		/* We copy to kernel buffer */
+		copied = vme_master_read(image[minor].resource,
+			image[minor].kern_buf, count, *ppos);
+		if (copied < 0) {
+			return (int)copied;
+		}
+
+		retval = __copy_to_user(buf, image[minor].kern_buf,
+			(unsigned long)copied);
+		if (retval != 0) {
+			copied = (copied - retval);
+			printk("User copy failed\n");
+			return -EINVAL;
+		}
+
+	} else {
+		/* XXX Need to write this */
+		printk("Currently don't support large transfers\n");
+		/* Map in pages from userspace */
+
+		/* Call vme_master_read to do the transfer */
+		return -EINVAL;
+	}
+
+	return copied;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go user space -> buffer -> VME. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly from the user space buffers out to VME.
+ */
+static ssize_t resource_from_user(unsigned int minor, const char *buf,
+	size_t count, loff_t *ppos)
+{
+	ssize_t retval;
+	ssize_t copied = 0;
+
+	if (count <= image[minor].size_buf) {
+		retval = __copy_from_user(image[minor].kern_buf, buf,
+			(unsigned long)count);
+		if (retval != 0)
+			copied = (copied - retval);
+		else
+			copied = count;
+
+		copied = vme_master_write(image[minor].resource,
+			image[minor].kern_buf, copied, *ppos);
+	} else {
+		/* XXX Need to write this */
+		printk("Currently don't support large transfers\n");
+		/* Map in pages from userspace */
+
+		/* Call vme_master_write to do the transfer */
+		return -EINVAL;
+	}
+
+	return copied;
+}
+
+static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
+	size_t count, loff_t *ppos)
+{
+	void __iomem *image_ptr;
+	ssize_t retval;
+
+	image_ptr = image[minor].kern_buf + *ppos;
+
+	retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
+	if (retval != 0) {
+		retval = (count - retval);
+		printk(KERN_WARNING "Partial copy to userspace\n");
+	} else
+		retval = count;
+
+	/* Return number of bytes successfully read */
+	return retval;
+}
+
+static ssize_t buffer_from_user(unsigned int minor, const char *buf,
+	size_t count, loff_t *ppos)
+{
+	void __iomem *image_ptr;
+	size_t retval;
+
+	image_ptr = image[minor].kern_buf + *ppos;
+
+	retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
+	if (retval != 0) {
+		retval = (count - retval);
+		printk(KERN_WARNING "Partial copy to userspace\n");
+	} else
+		retval = count;
+
+	/* Return number of bytes successfully read */
+	return retval;
+}
+
+static ssize_t vme_user_read(struct file *file, char *buf, size_t count,
+			loff_t * ppos)
+{
+	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+	ssize_t retval;
+	size_t image_size;
+	size_t okcount;
+
+	down(&image[minor].sem);
+
+	/* XXX Do we *really* want this helper - we can use vme_*_get ? */
+	image_size = vme_get_size(image[minor].resource);
+
+	/* Ensure we are starting at a valid location */
+	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+		up(&image[minor].sem);
+		return 0;
+	}
+
+	/* Ensure not reading past end of the image */
+	if (*ppos + count > image_size)
+		okcount = image_size - *ppos;
+	else
+		okcount = count;
+
+	switch (type[minor]){
+	case MASTER_MINOR:
+		retval = resource_to_user(minor, buf, okcount, ppos);
+		break;
+	case SLAVE_MINOR:
+		retval = buffer_to_user(minor, buf, okcount, ppos);
+		break;
+	default:
+		retval = -EINVAL;
+	}
+
+	up(&image[minor].sem);
+
+	if (retval > 0)
+		*ppos += retval;
+
+	return retval;
+}
+
+static ssize_t vme_user_write(struct file *file, const char *buf, size_t count,
+			 loff_t *ppos)
+{
+	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+	ssize_t retval;
+	size_t image_size;
+	size_t okcount;
+
+	down(&image[minor].sem);
+
+	image_size = vme_get_size(image[minor].resource);
+
+	/* Ensure we are starting at a valid location */
+	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+		up(&image[minor].sem);
+		return 0;
+	}
+
+	/* Ensure not reading past end of the image */
+	if (*ppos + count > image_size)
+		okcount = image_size - *ppos;
+	else
+		okcount = count;
+
+	switch (type[minor]){
+	case MASTER_MINOR:
+		retval = resource_from_user(minor, buf, okcount, ppos);
+		break;
+	case SLAVE_MINOR:
+		retval = buffer_from_user(minor, buf, okcount, ppos);
+		break;
+	default:
+		retval = -EINVAL;
+	}
+
+	up(&image[minor].sem);
+
+	if (retval > 0)
+		*ppos += retval;
+
+	return retval;
+}
+
+static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
+{
+	printk(KERN_ERR "Llseek currently incomplete\n");
+	return -EINVAL;
+}
+
+static int vme_user_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+#if 0
+	int ret_val;
+#endif
+	unsigned long copyRet;
+	vme_slave_t slave;
+
+	statistics.ioctls++;
+	switch (type[minor]) {
+	case CONTROL_MINOR:
+		break;
+	case MASTER_MINOR:
+		break;
+	case SLAVE_MINOR:
+		switch (cmd) {
+		case VME_SET_SLAVE:
+
+			copyRet = copy_from_user(&slave, (char *)arg,
+				sizeof(slave));
+			if (copyRet != 0) {
+				printk(KERN_WARNING "Partial copy from "
+					"userspace\n");
+				return -EFAULT;
+			}
+
+			return vme_slave_set(image[minor].resource,
+				slave.enable, slave.vme_addr, slave.size,
+				image[minor].pci_buf, slave.aspace,
+				slave.cycle);
+
+			break;
+#if 0
+		case VME_GET_SLAVE:
+			vme_slave_t slave;
+
+			ret_val = vme_slave_get(minor, &iRegs);
+
+			copyRet = copy_to_user((char *)arg, &slave,
+				sizeof(slave));
+			if (copyRet != 0) {
+				printk(KERN_WARNING "Partial copy to "
+					"userspace\n");
+				return -EFAULT;
+			}
+
+			return ret_val;
+			break;
+#endif
+		}
+		break;
+	}
+
+	return -EINVAL;
+}
+
+
+/*
+ * Unallocate a previously allocated buffer
+ */
+static void buf_unalloc (int num)
+{
+	if (image[num].kern_buf) {
+#ifdef VME_DEBUG
+		printk(KERN_DEBUG "UniverseII:Releasing buffer at %p\n",
+			image[num].pci_buf);
+#endif
+
+		vme_free_consistent(image[num].resource, image[num].size_buf,
+			image[num].kern_buf, image[num].pci_buf);
+
+		image[num].kern_buf = NULL;
+		image[num].pci_buf = 0;
+		image[num].size_buf = 0;
+
+#ifdef VME_DEBUG
+	} else {
+		printk(KERN_DEBUG "UniverseII: Buffer not allocated\n");
+#endif
+	}
+}
+
+static struct vme_driver vme_user_driver = {
+        .name = driver_name,
+        .probe = vme_user_probe,
+};
+
+
+/*
+ * In this simple access driver, the old behaviour is being preserved as much
+ * as practical. We will therefore reserve the buffers and request the images
+ * here so that we don't have to do it later.
+ */
+static int __init vme_bridge_init(void)
+{
+	int retval;
+	printk(KERN_INFO "VME User Space Access Driver\n");
+	printk("vme_user_driver:%p\n", &vme_user_driver);
+	retval = vme_register_driver(&vme_user_driver);
+	printk("vme_register_driver returned %d\n", retval);
+	return retval;
+}
+
+/*
+ * This structure gets passed a device, this should be the device created at
+ * registration.
+ */
+static int __init vme_user_probe(struct device *dev)
+{
+	int i, err;
+	char name[8];
+
+	printk("Running vme_user_probe()\n");
+
+	/* Pointer to the bridge device */
+	vme_user_bridge = dev;
+
+	/* Initialise descriptors */
+	for (i = 0; i < VME_DEVS; i++) {
+		image[i].kern_buf = NULL;
+		image[i].pci_buf = 0;
+		init_MUTEX(&(image[i].sem));
+		image[i].device = NULL;
+		image[i].resource = NULL;
+		image[i].users = 0;
+	}
+
+	/* Initialise statistics counters */
+	reset_counters();
+
+	/* Assign major and minor numbers for the driver */
+	err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
+		driver_name);
+	if (err) {
+		printk(KERN_WARNING "%s: Error getting Major Number %d for "
+		"driver.\n", driver_name, VME_MAJOR);
+		goto err_region;
+	}
+
+	/* Register the driver as a char device */
+	vme_user_cdev = cdev_alloc();
+	vme_user_cdev->ops = &vme_user_fops;
+	vme_user_cdev->owner = THIS_MODULE;
+	err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
+	if (err) {
+		printk(KERN_WARNING "%s: cdev_all failed\n", driver_name);
+		goto err_char;
+	}
+
+	/* Request slave resources and allocate buffers (128kB wide) */
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		/* XXX Need to properly request attributes */
+		image[i].resource = vme_slave_request(vme_user_bridge,
+			VME_A16, VME_SCT);
+		if (image[i].resource == NULL) {
+			printk(KERN_WARNING "Unable to allocate slave "
+				"resource\n");
+			goto err_buf;
+		}
+		image[i].size_buf = PCI_BUF_SIZE;
+		image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+			image[i].size_buf, &(image[i].pci_buf));
+		if (image[i].kern_buf == NULL) {
+			printk(KERN_WARNING "Unable to allocate memory for "
+				"buffer\n");
+			image[i].pci_buf = 0;
+			vme_slave_free(image[i].resource);
+			err = -ENOMEM;
+			goto err_buf;
+		}
+	}
+
+	/*
+	 * Request master resources allocate page sized buffers for small
+	 * reads and writes
+	 */
+	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+		/* XXX Need to properly request attributes */
+		image[i].resource = vme_master_request(vme_user_bridge,
+			VME_A32, VME_SCT, VME_D32);
+		if (image[i].resource == NULL) {
+			printk(KERN_WARNING "Unable to allocate master "
+				"resource\n");
+			goto err_buf;
+		}
+		image[i].size_buf = PAGE_SIZE;
+		image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+			image[i].size_buf, &(image[i].pci_buf));
+		if (image[i].kern_buf == NULL) {
+			printk(KERN_WARNING "Unable to allocate memory for "
+				"buffer\n");
+			image[i].pci_buf = 0;
+			vme_master_free(image[i].resource);
+			err = -ENOMEM;
+			goto err_buf;
+		}
+	}
+
+	/* Setup some debug windows */
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		err = vme_slave_set(image[i].resource, 1, 0x4000*(i-4),
+			0x4000, image[i].pci_buf, VME_A16,
+			VME_SCT | VME_SUPER | VME_USER | VME_PROG | VME_DATA);
+		if (err != 0) {
+			printk(KERN_WARNING "Failed to configure window\n");
+			goto err_buf;
+		}
+	}
+	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+		err = vme_master_set(image[i].resource, 1,
+			(0x10000 + (0x10000*i)), 0x10000,
+			VME_A32, VME_SCT | VME_USER | VME_DATA, VME_D32);
+		if (err != 0) {
+			printk(KERN_WARNING "Failed to configure window\n");
+			goto err_buf;
+		}
+	}
+
+	/* Create sysfs entries - on udev systems this creates the dev files */
+	vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
+	if (IS_ERR(vme_user_sysfs_class)) {
+		printk(KERN_ERR "Error creating vme_user class.\n");
+		err = PTR_ERR(vme_user_sysfs_class);
+		goto err_class;
+	}
+
+	/* Add sysfs Entries */
+	for (i=0; i<VME_DEVS; i++) {
+		switch (type[i]) {
+		case MASTER_MINOR:
+			sprintf(name,"bus/vme/m%%d");
+			break;
+		case CONTROL_MINOR:
+			sprintf(name,"bus/vme/ctl");
+			break;
+		case SLAVE_MINOR:
+			sprintf(name,"bus/vme/s%%d");
+			break;
+		default:
+			err = -EINVAL;
+			goto err_sysfs;
+			break;
+		}
+
+		image[i].device =
+			device_create(vme_user_sysfs_class, NULL,
+				MKDEV(VME_MAJOR, i), NULL, name,
+				(type[i] == SLAVE_MINOR)? i - (MASTER_MAX + 1) : i);
+		if (IS_ERR(image[i].device)) {
+			printk("%s: Error creating sysfs device\n",
+				driver_name);
+			err = PTR_ERR(image[i].device);
+			goto err_sysfs;
+		}
+	}
+
+	/* XXX Run tests */
+	/*
+	tests();
+	*/
+
+	return 0;
+
+	/* Ensure counter set correcty to destroy all sysfs devices */
+	i = VME_DEVS;
+err_sysfs:
+	while (i > 0){
+		i--;
+		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+	}
+	class_destroy(vme_user_sysfs_class);
+
+	/* Ensure counter set correcty to unalloc all slave buffers */
+	i = SLAVE_MAX + 1;
+err_buf:
+	while (i > SLAVE_MINOR){
+		i--;
+		vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
+		vme_slave_free(image[i].resource);
+		buf_unalloc(i);
+	}
+err_class:
+	cdev_del(vme_user_cdev);
+err_char:
+	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+err_region:
+	return err;
+}
+
+static void __exit vme_bridge_exit(void)
+{
+	int i;
+
+	/* Remove sysfs Entries */
+	for(i=0; i<VME_DEVS; i++) {
+		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+	}
+	class_destroy(vme_user_sysfs_class);
+
+	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+		buf_unalloc(i);
+	}
+
+	/* Unregister device driver */
+	cdev_del(vme_user_cdev);
+
+	/* Unregiser the major and minor device numbers */
+	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+}
+
+MODULE_DESCRIPTION("VME User Space Access Driver");
+MODULE_AUTHOR("Martyn Welch <[email protected]");
+MODULE_LICENSE("GPL");
+
+module_init(vme_bridge_init);
+module_exit(vme_bridge_exit);

drivers/staging/vme/devices/vme_user.h new file +43 -0

@@ -0,0 +1,43 @@
+
+/*
+ * VMEbus Master Window Configuration Structure
+ */
+typedef struct {
+	char enable;			/* State of Window */
+	unsigned long long vme_addr;	/* Starting Address on the VMEbus */
+	unsigned long long size;	/* Window Size */
+	vme_address_t aspace;		/* Address Space */
+	vme_cycle_t cycle;		/* Cycle properties */
+	vme_width_t dwidth;		/* Maximum Data Width */
+#if 0
+	char prefetchEnable;		/* Prefetch Read Enable State */
+	int prefetchSize;		/* Prefetch Read Size (Cache Lines) */
+	char wrPostEnable;		/* Write Post State */
+#endif
+} vme_master_t;
+
+
+/*
+ * IOCTL Commands and structures
+ */
+
+/* Magic number for use in ioctls */
+#define VME_IOC_MAGIC 0xAE
+
+
+/* VMEbus Slave Window Configuration Structure */
+typedef struct {
+	char enable;			/* State of Window */
+	unsigned long long vme_addr;	/* Starting Address on the VMEbus */
+	unsigned long long size;	/* Window Size */
+	vme_address_t aspace;		/* Address Space */
+	vme_cycle_t cycle;		/* Cycle properties */
+#if 0
+	char wrPostEnable;		/* Write Post State */
+	char rmwLock;			/* Lock PCI during RMW Cycles */
+	char data64BitCapable;		/* non-VMEbus capable of 64-bit Data */
+#endif
+} vme_slave_t;
+
+#define VME_SET_SLAVE _IOW(VME_IOC_MAGIC, 10, vme_slave_t)
+

drivers/staging/vme/Kconfig +2 -2

@@ -11,7 +11,7 @@ menuconfig VME
 if VME
 
 #source "drivers/staging/vme/bridges/Kconfig"
-#
-#source "drivers/staging/vme/devices/Kconfig"
+
+source "drivers/staging/vme/devices/Kconfig"
 
 endif # VME

drivers/staging/vme/Makefile +1 -1

@@ -4,4 +4,4 @@
 obj-$(CONFIG_VME)		+= vme.o
 
 #obj-y				+= bridges/
-#obj-y				+= devices/
+obj-y				+= devices/