wd719x: Introduce Western Digital WD7193/7197/7296 PCI SCSI card driver

Add read-only support for EEPROMs configured in 8-bit mode (ORG pin connected to GND).
This will be used by wd719x driver.

Signed-off-by Ondrej Zary <[email protected]>

Introduce wd719x, a driver for Western Digital WD7193, WD7197 and WD7296 PCI SCSI controllers based on WD33C296A chip.
Tested with WD7193 card.

Reviewed-by Christoph Hellwig <[email protected]>

Signed-off-by Ondrej Zary <[email protected]>

---
 drivers/scsi/Kconfig  |    8 +
 drivers/scsi/Makefile |    1 +
 drivers/scsi/wd719x.c | 1008 +++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/wd719x.h |  249 ++++++++++++
 4 files changed, 1266 insertions(+)
 create mode 100644 drivers/scsi/wd719x.c
 create mode 100644 drivers/scsi/wd719x.h

drivers/scsi/Kconfig +8 -0

index 3a820f6..fd81d14 100644
@@ -1451,6 +1451,14 @@ config SCSI_NSP32
 	  To compile this driver as a module, choose M here: the
 	  module will be called nsp32.
 
+config SCSI_WD719X
+	tristate "Western Digital WD7193/7197/7296 support"
+	depends on PCI && SCSI
+	select EEPROM_93CX6
+	---help---
+	  This is a driver for Western Digital WD7193, WD7197 and WD7296 PCI
+	  SCSI controllers (based on WD33C296A chip).
+
 config SCSI_DEBUG
 	tristate "SCSI debugging host simulator"
 	depends on SCSI

drivers/scsi/Makefile +1 -0

index 59f1ce6..d8bfca5 100644
@@ -143,6 +143,7 @@ obj-$(CONFIG_SCSI_VIRTIO)	+= virtio_scsi.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
 obj-$(CONFIG_XEN_SCSI_FRONTEND)	+= xen-scsifront.o
 obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
+obj-$(CONFIG_SCSI_WD719X)	+= wd719x.o
 
 obj-$(CONFIG_ARM)		+= arm/
 

drivers/scsi/wd719x.c new file +302 -0

new file mode 100644
index 0000000..ce6dafd
@@ -0,0 +1,1008 @@
+/*
+ * Driver for Western Digital WD7193, WD7197 and WD7296 SCSI cards
+ * Copyright 2013 Ondrej Zary
+ *
+ * Original driver by
+ * Aaron Dewell <[email protected]>
+ * Gaerti <[email protected]>
+ *
+ * HW documentation available in book:
+ *
+ * SPIDER Command Protocol
+ * by Chandru M. Sippy
+ * SCSI Storage Products (MCP)
+ * Western Digital Corporation
+ * 09-15-95
+ *
+ * http://web.archive.org/web/20070717175254/http://sun1.rrzn.uni-hannover.de/gaertner.juergen/wd719x/Linux/Docu/Spider/
+ */
+
+/*
+ * Driver workflow:
+ * 1. SCSI command is transformed to SCB (Spider Control Block) by the
+ *    queuecommand function.
+ * 2. The address of the SCB is stored in a list to be able to access it, if
+ *    something goes wrong.
+ * 3. The address of the SCB is written to the Controller, which loads the SCB
+ *    via BM-DMA and processes it.
+ * 4. After it has finished, it generates an interrupt, and sets registers.
+ *
+ * flaws:
+ *  - abort/reset functions
+ *
+ * ToDo:
+ *  - tagged queueing
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/firmware.h>
+#include <linux/eeprom_93cx6.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include "wd719x.h"
+
+/* low-level register access */
+static inline u8 wd719x_readb(struct wd719x *wd, u8 reg)
+{
+	return ioread8(wd->base + reg);
+}
+
+static inline u32 wd719x_readl(struct wd719x *wd, u8 reg)
+{
+	return ioread32(wd->base + reg);
+}
+
+static inline void wd719x_writeb(struct wd719x *wd, u8 reg, u8 val)
+{
+	iowrite8(val, wd->base + reg);
+}
+
+static inline void wd719x_writew(struct wd719x *wd, u8 reg, u16 val)
+{
+	iowrite16(val, wd->base + reg);
+}
+
+static inline void wd719x_writel(struct wd719x *wd, u8 reg, u32 val)
+{
+	iowrite32(val, wd->base + reg);
+}
+
+/* wait until the command register is ready */
+static inline int wd719x_wait_ready(struct wd719x *wd)
+{
+	int i = 0;
+
+	do {
+		if (wd719x_readb(wd, WD719X_AMR_COMMAND) == WD719X_CMD_READY)
+			return 0;
+		udelay(1);
+	} while (i++ < WD719X_WAIT_FOR_CMD_READY);
+
+	dev_err(&wd->pdev->dev, "command register is not ready: 0x%02x\n",
+		wd719x_readb(wd, WD719X_AMR_COMMAND));
+
+	return -ETIMEDOUT;
+}
+
+/* poll interrupt status register until command finishes */
+static inline int wd719x_wait_done(struct wd719x *wd, int timeout)
+{
+	u8 status;
+
+	while (timeout > 0) {
+		status = wd719x_readb(wd, WD719X_AMR_INT_STATUS);
+		if (status)
+			break;
+		timeout--;
+		udelay(1);
+	}
+
+	if (timeout <= 0) {
+		dev_err(&wd->pdev->dev, "direct command timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	if (status != WD719X_INT_NOERRORS) {
+		dev_err(&wd->pdev->dev, "direct command failed, status 0x%02x, SUE 0x%02x\n",
+			status, wd719x_readb(wd, WD719X_AMR_SCB_ERROR));
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int wd719x_direct_cmd(struct wd719x *wd, u8 opcode, u8 dev, u8 lun,
+			     u8 tag, dma_addr_t data, int timeout)
+{
+	int ret = 0;
+
+	/* clear interrupt status register (allow command register to clear) */
+	wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);
+
+	/* Wait for the Command register to become free */
+	if (wd719x_wait_ready(wd))
+		return -ETIMEDOUT;
+
+	/* make sure we get NO interrupts */
+	dev |= WD719X_DISABLE_INT;
+	wd719x_writeb(wd, WD719X_AMR_CMD_PARAM, dev);
+	wd719x_writeb(wd, WD719X_AMR_CMD_PARAM_2, lun);
+	wd719x_writeb(wd, WD719X_AMR_CMD_PARAM_3, tag);
+	if (data)
+		wd719x_writel(wd, WD719X_AMR_SCB_IN, data);
+
+	/* clear interrupt status register again */
+	wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);
+
+	/* Now, write the command */
+	wd719x_writeb(wd, WD719X_AMR_COMMAND, opcode);
+
+	if (timeout)	/* wait for the command to complete */
+		ret = wd719x_wait_done(wd, timeout);
+
+	/* clear interrupt status register (clean up) */
+	if (opcode != WD719X_CMD_READ_FIRMVER)
+		wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);
+
+	return ret;
+}
+
+static void wd719x_destroy(struct wd719x *wd)
+{
+	struct wd719x_scb *scb;
+
+	/* stop the RISC */
+	if (wd719x_direct_cmd(wd, WD719X_CMD_SLEEP, 0, 0, 0, 0,
+			      WD719X_WAIT_FOR_RISC))
+		dev_warn(&wd->pdev->dev, "RISC sleep command failed\n");
+	/* disable RISC */
+	wd719x_writeb(wd, WD719X_PCI_MODE_SELECT, 0);
+
+	/* free all SCBs */
+	list_for_each_entry(scb, &wd->active_scbs, list)
+		pci_free_consistent(wd->pdev, sizeof(struct wd719x_scb), scb,
+				    scb->phys);
+	list_for_each_entry(scb, &wd->free_scbs, list)
+		pci_free_consistent(wd->pdev, sizeof(struct wd719x_scb), scb,
+				    scb->phys);
+	/* free internal buffers */
+	pci_free_consistent(wd->pdev, wd->fw_size, wd->fw_virt, wd->fw_phys);
+	wd->fw_virt = NULL;
+	pci_free_consistent(wd->pdev, WD719X_HASH_TABLE_SIZE, wd->hash_virt,
+			    wd->hash_phys);
+	wd->hash_virt = NULL;
+	pci_free_consistent(wd->pdev, sizeof(struct wd719x_host_param),
+			    wd->params, wd->params_phys);
+	wd->params = NULL;
+	free_irq(wd->pdev->irq, wd);
+}
+
+/* finish a SCSI command, mark SCB (if any) as free, unmap buffers */
+static void wd719x_finish_cmd(struct scsi_cmnd *cmd, int result)
+{
+	struct wd719x *wd = shost_priv(cmd->device->host);
+	struct wd719x_scb *scb = (struct wd719x_scb *) cmd->host_scribble;
+
+	if (scb) {
+		list_move(&scb->list, &wd->free_scbs);
+		dma_unmap_single(&wd->pdev->dev, cmd->SCp.dma_handle,
+				 SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+		scsi_dma_unmap(cmd);
+	}
+	cmd->result = result << 16;
+	cmd->scsi_done(cmd);
+}
+
+static int wd719x_send_scb(struct wd719x_scb *scb)
+{
+	struct wd719x *wd = shost_priv(scb->cmd->device->host);
+
+	/* wait for the Command register to become free */
+	if (wd719x_wait_ready(wd))
+		return DID_TIME_OUT;
+
+	/* first write pointer to the AMR */
+	wd719x_writel(wd, WD719X_AMR_SCB_IN, scb->phys);
+	/* send SCB opcode */
+	wd719x_writeb(wd, WD719X_AMR_COMMAND, WD719X_CMD_PROCESS_SCB);
+
+	return DID_OK;
+}
+
+/* Build a SCB and send it to the card using send_scb */
+static int wd719x_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
+{
+	int i, result, count_sg;
+	unsigned long flags;
+	struct wd719x_scb *scb;
+	struct wd719x *wd = shost_priv(sh);
+	dma_addr_t phys;
+
+	cmd->host_scribble = NULL;
+
+	/* get a free SCB - either from existing ones or allocate a new one */
+	spin_lock_irqsave(wd->sh->host_lock, flags);
+	scb = list_first_entry_or_null(&wd->free_scbs, struct wd719x_scb, list);
+	if (scb) {
+		list_del(&scb->list);
+		phys = scb->phys;
+	} else {
+		spin_unlock_irqrestore(wd->sh->host_lock, flags);
+		scb = pci_alloc_consistent(wd->pdev, sizeof(struct wd719x_scb),
+					   &phys);
+		spin_lock_irqsave(wd->sh->host_lock, flags);
+		if (!scb) {
+			dev_err(&wd->pdev->dev, "unable to allocate SCB\n");
+			wd719x_finish_cmd(cmd, DID_ERROR);
+			spin_unlock_irqrestore(wd->sh->host_lock, flags);
+			return 0;
+		}
+	}
+	memset(scb, 0, sizeof(struct wd719x_scb));
+	list_add(&scb->list, &wd->active_scbs);
+
+	scb->phys = phys;
+	scb->cmd = cmd;
+	cmd->host_scribble = (char *) scb;
+
+	scb->CDB_tag = 0;	/* Tagged queueing not supported yet */
+	scb->devid = cmd->device->id;
+	scb->lun = cmd->device->lun;
+
+	/* copy the command */
+	memcpy(scb->CDB, cmd->cmnd, cmd->cmd_len);
+
+	/* map sense buffer */
+	scb->sense_buf_length = SCSI_SENSE_BUFFERSIZE;
+	cmd->SCp.dma_handle = dma_map_single(&wd->pdev->dev, cmd->sense_buffer,
+			SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+	dma_cache_sync(&wd->pdev->dev, cmd->sense_buffer,
+			SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+	scb->sense_buf = cpu_to_le32(cmd->SCp.dma_handle);
+
+	/* request autosense */
+	scb->SCB_options |= WD719X_SCB_FLAGS_AUTO_REQUEST_SENSE;
+
+	/* check direction */
+	if (cmd->sc_data_direction == DMA_TO_DEVICE)
+		scb->SCB_options |= WD719X_SCB_FLAGS_CHECK_DIRECTION
+				 |  WD719X_SCB_FLAGS_PCI_TO_SCSI;
+	else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
+		scb->SCB_options |= WD719X_SCB_FLAGS_CHECK_DIRECTION;
+
+	/* Scather/gather */
+	count_sg = scsi_dma_map(cmd);
+	if (count_sg < 0) {
+		wd719x_finish_cmd(cmd, DID_ERROR);
+		spin_unlock_irqrestore(wd->sh->host_lock, flags);
+		return 0;
+	}
+	BUG_ON(count_sg > WD719X_SG);
+
+	if (count_sg) {
+		struct scatterlist *sg;
+
+		scb->data_length = cpu_to_le32(count_sg *
+					       sizeof(struct wd719x_sglist));
+		scb->data_p = cpu_to_le32(scb->phys +
+					  offsetof(struct wd719x_scb, sg_list));
+
+		scsi_for_each_sg(cmd, sg, count_sg, i) {
+			scb->sg_list[i].ptr = cpu_to_le32(sg_dma_address(sg));
+			scb->sg_list[i].length = cpu_to_le32(sg_dma_len(sg));
+		}
+		scb->SCB_options |= WD719X_SCB_FLAGS_DO_SCATTER_GATHER;
+	} else { /* zero length */
+		scb->data_length = 0;
+		scb->data_p = 0;
+	}
+

Quoted 6 lines · Ondrej Zary

Introduce wd719x, a driver for Western Digital WD7193, WD7197 and WD7296 PCI SCSI controllers based on WD33C296A chip.
Tested with WD7193 card.

Reviewed-by Christoph Hellwig <[email protected]>

Signed-off-by Ondrej Zary <[email protected]>

Quoted 9 lines

drivers/scsi/wd719x.c new file +9 -0

+	result = wd719x_send_scb(scb);
+	if (result != DID_OK) {
+		dev_warn(&wd->pdev->dev, "can't queue SCB\n");
+		wd719x_finish_cmd(cmd, result);
+	}
+
+	spin_unlock_irqrestore(wd->sh->host_lock, flags);
+
+	return 0;

Quoted 1 line

+}

Why did you use 'wait_ready' here?
Any sane HBA driver should set the queue depth parameters correctly to avoid this from happening.
Wouldn't it be far better to just return HOST_BUSY here if the command register isn't free and submit the command directly otherwise?