reserved-memory regions/CMA in devicetree, again

From: Grant Likely <[email protected]>

Reserved memory nodes allow for the reservation of static (fixed address) regions, or dynamically allocated regions for a specific purpose.

Signed-off-by Grant Likely <[email protected]>

[joshc: Based on binding document proposed (in non-patch form) here:
http://lkml.kernel.org/g/20131030134702.19B57C402A0 at trevor.secretlab.ca adapted to support #memory-region-cells]

Signed-off-by Josh Cartwright <[email protected]>

[mszyprow: removed #memory-region-cells property]

Signed-off-by Marek Szyprowski <[email protected]>

---
 .../bindings/reserved-memory/reserved-memory.txt   |  136 ++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt

Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt new file +136 -0

new file mode 100644
index 000000000000..8b0d747a38e7
@@ -0,0 +1,136 @@
+*** Reserved memory regions ***
+
+Reserved memory is specified as a node under the /reserved-memory node.
+The operating system shall exclude reserved memory from normal usage
+one can create child nodes describing particular reserved (excluded from
+normal use) memory regions. Such memory regions are usually designed for
+the special usage by various device drivers.
+
+Parameters for each memory region can be encoded into the device tree
+with the following nodes:
+
+/reserved-memory node
+---------------------
+#address-cells, #size-cells (required) - standard definition
+    - Should use the same values as the root node
+ranges (required) - standard definition
+    - Should be empty
+
+/reserved-memory/ child nodes
+-----------------------------
+Each child of the reserved-memory node specifies one or more regions of
+reserved memory. Each child node may either use a 'reg' property to
+specify a specific range of reserved memory, or a 'size' property with
+optional constraints to request a dynamically allocated block of memory.
+
+Following the generic-names recommended practice, node names should
+reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). Unit
+address (@<address>) should be appended to the name if the node is a
+static allocation.
+
+Properties:
+Requires either a) or b) below.
+a) static allocation
+   reg (required) - standard definition
+b) dynamic allocation
+   size (required) - length based on parent's #size-cells
+                   - Size in bytes of memory to reserve.
+   alignment (optional) - length based on parent's #size-cells
+                        - Address boundary for alignment of allocation.
+   alloc-ranges (optional) - prop-encoded-array (address, length pairs).
+                           - Specifies regions of memory that are
+                             acceptable to allocate from.
+
+If both reg and size are present, then the reg property takes precedence
+and size is ignored.
+
+Additional properties:
+compatible (optional) - standard definition
+    - may contain the following strings:
+        - shared-dma-pool: This indicates a region of memory meant to be
+          used as a shared pool of DMA buffers for a set of devices. It can
+          be used by an operating system to instanciate the necessary pool
+          management subsystem if necessary.
+        - vendor specific string in the form <vendor>,[<device>-]<usage>
+no-map (optional) - empty property
+    - Indicates the operating system must not create a virtual mapping
+      of the region as part of its standard mapping of system memory,
+      nor permit speculative access to it under any circumstances other
+      than under the control of the device driver using the region.
+reusable (optional) - empty property
+    - The operating system can use the memory in this region with the
+      limitation that the device driver(s) owning the region need to be
+      able to reclaim it back. Typically that means that the operating
+      system can use that region to store volatile or cached data that
+      can be otherwise regenerated or migrated elsewhere.
+
+Linux implementation note:
+- If a "linux,cma-default" property is present, then Linux will use the
+  region for the default pool of the contiguous memory allocator.
+
+Device node references to reserved memory
+-----------------------------------------
+Regions in the /reserved-memory node may be referenced by other device
+nodes by adding a memory-region property to the device node.
+
+memory-region (optional) - phandle, specifier pairs to children of /reserved-memory
+
+Example
+-------
+This example defines 3 contiguous regions are defined for Linux kernel:
+one default of all device drivers (named linux,cma at 72000000 and 64MiB in size),
+one dedicated to the framebuffer device (named framebuffer at 78000000, 8MiB), and
+one for multimedia processing (named multimedia-memory at 77000000, 64MiB).
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	memory {
+		reg = <0x40000000 0x40000000>;
+	};
+
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		/* global autoconfigured region for contiguous allocations */
+		linux,cma {
+			compatible = "shared-dma-pool";
+			reusable;
+			#memory-region-cells = <0>;
+			size = <0x4000000>;
+			alignment = <0x2000>;
+			linux,cma-default;
+		};
+
+		display_reserved: framebuffer at 78000000 {
+			#memory-region-cells = <0>;
+			reg = <0x78000000 0x800000>;
+		};
+
+		multimedia_reserved: multimedia at 77000000 {
+			compatible = "acme,multimedia-memory";
+			#memory-region-cells = <1>;
+			reg = <0x77000000 0x4000000>;
+		};
+	};
+
+	/* ... */
+
+	fb0: video at 12300000 {
+		memory-region = <&display_reserved>;
+		/* ... */
+	};
+
+	scaler: scaler at 12500000 {
+		memory-region = <&multimedia_reserved 0xdeadbeef>;
+		/* ... */
+	};
+
+	codec: codec at 12600000 {
+		memory-region = <&multimedia_reserved 0xfeebdaed>;
+		/* ... */
+	};
+};

Signature · 1 line

1.7.9.5

This patch adds support for static (defined by 'reg' property) reserved memory regions declared in device tree.

Memory blocks can be reliably reserved only during early boot. This must happen before the whole memory management subsystem is initialized, because we need to ensure that the given contiguous blocks are not yet allocated by kernel. Also it must happen before kernel mappings for the whole low memory are created, to ensure that there will be no mappings (for reserved blocks). Typically, all this happens before device tree structures are unflattened, so we need to get reserved memory layout directly from fdt.

Based on previous code provided by Josh Cartwright <[email protected]>

Signed-off-by Marek Szyprowski <[email protected]>

Acked-by Grant Likely <[email protected]>

---
 drivers/of/fdt.c       |  131 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of_fdt.h |    3 ++
 2 files changed, 134 insertions(+)

drivers/of/fdt.c +131 -0

index 758b4f8b30b7..819e11209718 100644
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
+#include <linux/sizes.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/slab.h>

@@ -440,6 +441,118 @@ struct boot_param_header *initial_boot_params;
 #ifdef CONFIG_OF_EARLY_FLATTREE
 
 /**
+ * res_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+					     const char *uname)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t base, size;
+	unsigned long len;
+	__be32 *prop;
+	int nomap;
+
+	prop = of_get_flat_dt_prop(node, "reg", &len);
+	if (!prop)
+		return -ENOENT;
+
+	if (len && len % t_len != 0) {
+		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+		       uname);
+		return -EINVAL;
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	while (len >= t_len) {
+		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+		size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+		if (base && size &&
+		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
+			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+		else
+			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+
+		len -= t_len;
+	}
+	return 0;
+}
+
+/**
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __reserved_mem_check_root(unsigned long node)
+{
+	__be32 *prop;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "ranges", NULL);
+	if (!prop)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
+					  int depth, void *data)
+{
+	static int found;
+	const char *status;
+
+	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
+		if (__reserved_mem_check_root(node) != 0) {
+			pr_err("Reserved memory: unsupported node format, ignoring\n");
+			/* break scan */
+			return 1;
+		}
+		found = 1;
+		/* scan next node */
+		return 0;
+	} else if (!found) {
+		/* scan next node */
+		return 0;
+	} else if (found && depth < 2) {
+		/* scanning of /reserved-memory has been finished */
+		return 1;
+	}
+
+	status = of_get_flat_dt_prop(node, "status", NULL);
+	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
+		return 0;
+
+	__reserved_mem_reserve_reg(node, uname);
+
+	/* scan next node */
+	return 0;
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+}
+
+/**
  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
  * @it: callback function
  * @data: context data pointer

@@ -856,6 +969,16 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	if (memblock_is_region_reserved(base, size))
+		return -EBUSY;
+	if (nomap)
+		return memblock_remove(base, size);
+	return memblock_reserve(base, size);
+}
+
 /*
  * called from unflatten_device_tree() to bootstrap devicetree itself
  * Architectures can override this definition if memblock isn't used

@@ -864,6 +987,14 @@ void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
 {
 	return __va(memblock_alloc(size, align));
 }
+#else
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
+		  base, size, nomap ? " (nomap)" : "");
+	return -ENOSYS;
+}
 #endif
 
 bool __init early_init_dt_scan(void *params)

include/linux/of_fdt.h +3 -0

index 2b77058a7335..8610ad8d77d2 100644
@@ -98,7 +98,10 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
 				     int depth, void *data);
 extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
 				     int depth, void *data);
+extern void early_init_fdt_scan_reserved_mem(void);
 extern void early_init_dt_add_memory_arch(u64 base, u64 size);
+extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
+					     bool no_map);
 extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
 extern u64 dt_mem_next_cell(int s, __be32 **cellp);
 

Signature · 1 line

1.7.9.5

This patch adds support for dynamically allocated reserved memory regions declared in device tree. Such regions are defined by 'size', 'alignment' and 'alloc-ranges' properties.

Based on previous code provided by Josh Cartwright <[email protected]>

Signed-off-by Marek Szyprowski <[email protected]>

Acked-by Grant Likely <[email protected]>

---
 drivers/of/Kconfig              |    6 ++
 drivers/of/Makefile             |    1 +
 drivers/of/fdt.c                |   13 ++-
 drivers/of/of_reserved_mem.c    |  188 +++++++++++++++++++++++++++++++++++++++
 include/linux/of_reserved_mem.h |   21 +++++
 5 files changed, 227 insertions(+), 2 deletions(-)
 create mode 100644 drivers/of/of_reserved_mem.c
 create mode 100644 include/linux/of_reserved_mem.h

drivers/of/Kconfig +6 -0

index c6973f101a3e..30a7d87a8077 100644
@@ -75,4 +75,10 @@ config OF_MTD
 	depends on MTD
 	def_bool y
 
+config OF_RESERVED_MEM
+	depends on OF_EARLY_FLATTREE
+	bool
+	help
+	  Helpers to allow for reservation of memory regions
+
 endmenu # OF

drivers/of/Makefile +1 -0

index efd05102c405..ed9660adad77 100644
@@ -9,3 +9,4 @@ obj-$(CONFIG_OF_MDIO)	+= of_mdio.o
 obj-$(CONFIG_OF_PCI)	+= of_pci.o
 obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
 obj-$(CONFIG_OF_MTD)	+= of_mtd.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o

drivers/of/fdt.c +11 -2

index 819e11209718..510c0d8de8a0 100644
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/sizes.h>
 #include <linux/string.h>
 #include <linux/errno.h>

@@ -450,7 +451,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 	phys_addr_t base, size;
 	unsigned long len;
 	__be32 *prop;
-	int nomap;
+	int nomap, first = 1;
 
 	prop = of_get_flat_dt_prop(node, "reg", &len);
 	if (!prop)

@@ -477,6 +478,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 				uname, &base, (unsigned long)size / SZ_1M);
 
 		len -= t_len;
+		if (first) {
+			fdt_reserved_mem_save_node(node, uname, base, size);
+			first = 0;
+		}
 	}
 	return 0;
 }

@@ -512,6 +517,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 {
 	static int found;
 	const char *status;
+	int err;
 
 	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 		if (__reserved_mem_check_root(node) != 0) {

@@ -534,7 +540,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 		return 0;
 
-	__reserved_mem_reserve_reg(node, uname);
+	err = __reserved_mem_reserve_reg(node, uname);
+	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
+		fdt_reserved_mem_save_node(node, uname, 0, 0);
 
 	/* scan next node */
 	return 0;

@@ -550,6 +558,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 void __init early_init_fdt_scan_reserved_mem(void)
 {
 	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+	fdt_init_reserved_mem();
 }
 
 /**

drivers/of/of_reserved_mem.c new file +188 -0

new file mode 100644
index 000000000000..69b811779585
@@ -0,0 +1,188 @@
+/*
+ * Device tree based initialization code for reserved memory.
+ *
+ * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Author: Marek Szyprowski <[email protected]>
+ * Author: Josh Cartwright <[email protected]>
+ *
+ * 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 optional) any later version of the license.
+ */
+
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/of_reserved_mem.h>
+
+#define MAX_RESERVED_REGIONS	16
+static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
+static int reserved_mem_count;
+
+#if defined(CONFIG_HAVE_MEMBLOCK)
+#include <linux/memblock.h>
+int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	/*
+	 * We use __memblock_alloc_base() because memblock_alloc_base()
+	 * panic()s on allocation failure.
+	 */
+	phys_addr_t base = __memblock_alloc_base(size, align, end);
+	if (!base)
+		return -ENOMEM;
+
+	/*
+	 * Check if the allocated region fits in to start..end window
+	 */
+	if (base < start) {
+		memblock_free(base, size);
+		return -ENOMEM;
+	}
+
+	*res_base = base;
+	if (nomap)
+		return memblock_remove(base, size);
+	return 0;
+}
+#else
+int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
+		  size, nomap ? " (nomap)" : "");
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * res_mem_save_node() - save fdt node for second pass initialization
+ */
+void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+				      phys_addr_t base, phys_addr_t size)
+{
+	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
+
+	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
+		pr_err("Reserved memory: not enough space all defined regions.\n");
+		return;
+	}
+
+	rmem->fdt_node = node;
+	rmem->name = uname;
+	rmem->base = base;
+	rmem->size = size;
+
+	reserved_mem_count++;
+	return;
+}
+
+/**
+ * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
+ *			  and 'alloc-ranges' properties
+ */
+static int __init __reserved_mem_alloc_size(unsigned long node,
+	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t start = 0, end = 0;
+	phys_addr_t base = 0, align = 0, size;
+	unsigned long len;
+	__be32 *prop;
+	int nomap;
+	int ret;
+
+	prop = of_get_flat_dt_prop(node, "size", &len);
+	if (!prop)
+		return -EINVAL;
+
+	if (len != dt_root_size_cells * sizeof(__be32)) {
+		pr_err("Reserved memory: invalid size property in '%s' node.\n",
+				uname);
+		return -EINVAL;
+	}
+	size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	prop = of_get_flat_dt_prop(node, "alignment", &len);
+	if (prop) {
+		if (len != dt_root_addr_cells * sizeof(__be32)) {
+			pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
+				uname);
+			return -EINVAL;
+		}
+		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	}
+
+	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
+	if (prop) {
+
+		if (len % t_len != 0) {
+			pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
+			       uname);
+			return -EINVAL;
+		}
+
+		base = 0;
+
+		while (len > 0) {
+			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
+			end = start + dt_mem_next_cell(dt_root_size_cells,
+						       &prop);
+
+			ret = early_init_dt_alloc_reserved_memory_arch(size,
+					align, start, end, nomap, &base);
+			if (ret == 0) {
+				pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
+					uname, &base,
+					(unsigned long)size / SZ_1M);
+				break;
+			}
+			len -= t_len;
+		}
+
+	} else {
+		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+							0, 0, nomap, &base);
+		if (ret == 0)
+			pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+	}
+
+	if (base == 0) {
+		pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
+			uname);
+		return -ENOMEM;
+	}
+
+	*res_base = base;
+	*res_size = size;
+
+	return 0;
+}
+
+/**
+ * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
+ */
+void __init fdt_init_reserved_mem(void)
+{
+	int i;
+	for (i = 0; i < reserved_mem_count; i++) {
+		struct reserved_mem *rmem = &reserved_mem[i];
+		unsigned long node = rmem->fdt_node;
+		int err = 0;
+
+		if (rmem->size == 0)
+			err = __reserved_mem_alloc_size(node, rmem->name,
+						 &rmem->base, &rmem->size);
+	}
+}

include/linux/of_reserved_mem.h new file +21 -0

new file mode 100644
index 000000000000..89226ed7d954
@@ -0,0 +1,21 @@
+#ifndef __OF_RESERVED_MEM_H
+#define __OF_RESERVED_MEM_H
+
+struct reserved_mem {
+	const char			*name;
+	unsigned long			fdt_node;
+	phys_addr_t			base;
+	phys_addr_t			size;
+};
+
+#ifdef CONFIG_OF_RESERVED_MEM
+void fdt_init_reserved_mem(void);
+void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+			       phys_addr_t base, phys_addr_t size);
+#else
+static inline void fdt_init_reserved_mem(void) { }
+static inline void fdt_reserved_mem_save_node(unsigned long node,
+		const char *uname, phys_addr_t base, phys_addr_t size) { }
+#endif
+
+#endif /* __OF_RESERVED_MEM_H */

Signature · 1 line

1.7.9.5

Add support for custom reserved memory drivers. Call their init() function for each reserved region and prepare for using operations provided by them with by the reserved_mem->ops array.

Based on previous code provided by Josh Cartwright <[email protected]>

Signed-off-by Marek Szyprowski <[email protected]>

---
 drivers/of/of_reserved_mem.c      |   29 +++++++++++++++++++++++++++++
 include/asm-generic/vmlinux.lds.h |   11 +++++++++++
 include/linux/of_reserved_mem.h   |   32 ++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+)

drivers/of/of_reserved_mem.c +29 -0

index 69b811779585..daaaf935911d 100644
@@ -170,6 +170,33 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
 	return 0;
 }
 
+static const struct of_device_id __rmem_of_table_sentinel
+	__used __section(__reservedmem_of_table_end);
+
+/**
+ * res_mem_init_node() - call region specific reserved memory init code
+ */
+static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
+{
+	extern const struct of_device_id __reservedmem_of_table[];
+	const struct of_device_id *i;
+
+	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
+		reservedmem_of_init_fn initfn = i->data;
+		const char *compat = i->compatible;
+
+		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
+			continue;
+
+		if (initfn(rmem, rmem->fdt_node, rmem->name) == 0) {
+			pr_info("Reserved memory: initialized node %s, compatible id %s\n",
+				rmem->name, compat);
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
 /**
  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
  */

@@ -184,5 +211,7 @@ void __init fdt_init_reserved_mem(void)
 		if (rmem->size == 0)
 			err = __reserved_mem_alloc_size(node, rmem->name,
 						 &rmem->base, &rmem->size);
+		if (err == 0)
+			__reserved_mem_init_node(rmem);
 	}
 }

include/asm-generic/vmlinux.lds.h +11 -0

index bc2121fa9132..f10f64fcc815 100644
@@ -167,6 +167,16 @@
 #define CLK_OF_TABLES()
 #endif
 
+#ifdef CONFIG_OF_RESERVED_MEM
+#define RESERVEDMEM_OF_TABLES()				\
+	. = ALIGN(8);					\
+	VMLINUX_SYMBOL(__reservedmem_of_table) = .;	\
+	*(__reservedmem_of_table)			\
+	*(__reservedmem_of_table_end)
+#else
+#define RESERVEDMEM_OF_TABLES()
+#endif
+
 #define KERNEL_DTB()							\
 	STRUCT_ALIGN();							\
 	VMLINUX_SYMBOL(__dtb_start) = .;				\

@@ -490,6 +500,7 @@
 	TRACE_SYSCALLS()						\
 	MEM_DISCARD(init.rodata)					\
 	CLK_OF_TABLES()							\
+	RESERVEDMEM_OF_TABLES()						\
 	CLKSRC_OF_TABLES()						\
 	KERNEL_DTB()							\
 	IRQCHIP_OF_MATCH_TABLE()

include/linux/of_reserved_mem.h +32 -0

index 89226ed7d954..9b1fbb7f29fc 100644
@@ -1,21 +1,53 @@
 #ifndef __OF_RESERVED_MEM_H
 #define __OF_RESERVED_MEM_H
 
+struct device;
+struct of_phandle_args;
+struct reserved_mem_ops;
+
 struct reserved_mem {
 	const char			*name;
 	unsigned long			fdt_node;
+	const struct reserved_mem_ops	*ops;
 	phys_addr_t			base;
 	phys_addr_t			size;
+	void				*priv;
+};
+
+struct reserved_mem_ops {
+	void	(*device_init)(struct reserved_mem *rmem,
+			       struct device *dev);
+	void	(*device_release)(struct reserved_mem *rmem,
+				  struct device *dev);
 };
 
+typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem,
+				      unsigned long node, const char *uname);
+
 #ifdef CONFIG_OF_RESERVED_MEM
 void fdt_init_reserved_mem(void);
 void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
 			       phys_addr_t base, phys_addr_t size);
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
+	static const struct of_device_id __reservedmem_of_table_##name	\
+		__used __section(__reservedmem_of_table)		\
+		 = { .compatible = compat,				\
+		     .data = (init == (reservedmem_of_init_fn)NULL) ?	\
+				init : init }
+
 #else
 static inline void fdt_init_reserved_mem(void) { }
 static inline void fdt_reserved_mem_save_node(unsigned long node,
 		const char *uname, phys_addr_t base, phys_addr_t size) { }
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
+	static const struct of_device_id __reservedmem_of_table_##name	\
+		__attribute__((unused))					\
+		 = { .compatible = compat,				\
+		     .data = (init == (reservedmem_of_init_fn)NULL) ?	\
+				init : init }
+
 #endif
 
 #endif /* __OF_RESERVED_MEM_H */

Signature · 1 line

1.7.9.5

This patch adds code for automated assignment of reserved memory regions to struct device. reserved_mem->ops->device_init()/device_cleanup() callbacks are called to perform reserved memory driver specific initialization and cleanup

Based on previous code provided by Josh Cartwright <[email protected]>

Signed-off-by Marek Szyprowski <[email protected]>

---
 drivers/of/of_reserved_mem.c    |   70 +++++++++++++++++++++++++++++++++++++++
 include/linux/of_reserved_mem.h |    7 ++++
 2 files changed, 77 insertions(+)

drivers/of/of_reserved_mem.c +70 -0

index daaaf935911d..5c45016efd31 100644
@@ -206,8 +206,16 @@ void __init fdt_init_reserved_mem(void)
 	for (i = 0; i < reserved_mem_count; i++) {
 		struct reserved_mem *rmem = &reserved_mem[i];
 		unsigned long node = rmem->fdt_node;
+		unsigned long len;
+		__be32 *prop;
 		int err = 0;
 
+		prop = of_get_flat_dt_prop(node, "phandle", &len);
+		if (!prop)
+			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
+		if (prop)
+			rmem->phandle = of_read_number(prop, len/4);
+
 		if (rmem->size == 0)
 			err = __reserved_mem_alloc_size(node, rmem->name,
 						 &rmem->base, &rmem->size);

@@ -215,3 +223,65 @@ void __init fdt_init_reserved_mem(void)
 			__reserved_mem_init_node(rmem);
 	}
 }
+
+static inline struct reserved_mem *__find_rmem(struct device_node *node)
+{
+	unsigned int i;
+
+	if (!node->phandle)
+		return NULL;
+
+	for (i = 0; i < reserved_mem_count; i++)
+		if (reserved_mem[i].phandle == node->phandle)
+			return &reserved_mem[i];
+	return NULL;
+}
+
+/**
+ * of_reserved_mem_device_init() - assign reserved memory region to given device
+ *
+ * This function assign memory region pointed by "memory-region" device tree
+ * property to the given device.
+ */
+void of_reserved_mem_device_init(struct device *dev)
+{
+	struct reserved_mem *rmem;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "memory-region", 0);
+	if (!np)
+		return;
+
+	rmem = __find_rmem(np);
+	of_node_put(np);
+
+	if (!rmem || !rmem->ops || !rmem->ops->device_init)
+		return;
+
+	rmem->ops->device_init(rmem, dev);
+	dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+}
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ *
+ * This function releases structures allocated for memory region handling for
+ * the given device.
+ */
+void of_reserved_mem_device_release(struct device *dev)
+{
+	struct reserved_mem *rmem;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "memory-region", 0);
+	if (!np)
+		return;
+
+	rmem = __find_rmem(np);
+	of_node_put(np);
+
+	if (!rmem || !rmem->ops || !rmem->ops->device_release)
+		return;
+
+	rmem->ops->device_release(rmem, dev);
+}

include/linux/of_reserved_mem.h +7 -0

index 9b1fbb7f29fc..6a54e6565b89 100644
@@ -8,6 +8,7 @@ struct reserved_mem_ops;
 struct reserved_mem {
 	const char			*name;
 	unsigned long			fdt_node;
+	unsigned long			phandle;
 	const struct reserved_mem_ops	*ops;
 	phys_addr_t			base;
 	phys_addr_t			size;

@@ -25,6 +26,9 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem,
 				      unsigned long node, const char *uname);
 
 #ifdef CONFIG_OF_RESERVED_MEM
+void of_reserved_mem_device_init(struct device *dev);
+void of_reserved_mem_device_release(struct device *dev);
+
 void fdt_init_reserved_mem(void);
 void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
 			       phys_addr_t base, phys_addr_t size);

@@ -37,6 +41,9 @@ void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
 				init : init }
 
 #else
+static inline void of_reserved_mem_device_init(struct device *dev) { }
+static inline void of_reserved_mem_device_release(struct device *pdev) { }
+
 static inline void fdt_init_reserved_mem(void) { }
 static inline void fdt_reserved_mem_save_node(unsigned long node,
 		const char *uname, phys_addr_t base, phys_addr_t size) { }

Signature · 1 line

1.7.9.5

Quoted 7 lines · Marek Szyprowski

This patch adds code for automated assignment of reserved memory regions to struct device. reserved_mem->ops->device_init()/device_cleanup() callbacks are called to perform reserved memory driver specific initialization and cleanup

Based on previous code provided by Josh Cartwright <[email protected]>

Quoted 1 line

Signed-off-by Marek Szyprowski <[email protected]>

Hi Marek,

I've not applied this one yet, only because there is still the open issue of whether or not these functions should be called from drivers or from core code. I don't actually have any problems with the content of this patch. Once the user is sorted out I'll merge it.

Quoted 8 lines · Grant Likely

Quoted 7 lines · Marek Szyprowski

This patch adds code for automated assignment of reserved memory regions to struct device. reserved_mem->ops->device_init()/device_cleanup() callbacks are called to perform reserved memory driver specific initialization and cleanup

Based on previous code provided by Josh Cartwright <[email protected]>

Quoted 8 lines

Quoted 1 line

Signed-off-by Marek Szyprowski <[email protected]>

Hi Marek,

I've not applied this one yet, only because there is still the open issue of whether or not these functions should be called from drivers or from core code. I don't actually have any problems with the content of this patch. Once the user is sorted out I'll merge it.

Has anything more come of these patches? I see some of the series is now in Linux 3.15, but the actual patches to let people use the feature aren't there yet, namely patches 5 though 8.

My personal immediate interest in these is as a mechanism on arm64 to limit CMA to a region of memory that is actually DMA-able devices (e.g. below 4GB for 32-bit devices without an iommu).

For reference, the mail archives for this series is at
http://lkml.org/lkml/2014/2/28/237

Enable reserved memory initialization from device tree.

Signed-off-by Marek Szyprowski <[email protected]>

Quoted 3 lines · Marek Szyprowski

Enable reserved memory initialization from device tree.

Signed-off-by Marek Szyprowski <[email protected]>

Acked-by Catalin Marinas <[email protected]>

Hello again!

Here is another update of the support for reserved memory regions in device tree. I've fixes a few more minor issues pointed by Grant. See changelog for more details.

The initial code for this feature were posted here [1], merged as commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add initialization code for dma reserved memory") and later reverted by commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information, see [2]. Finally a new bindings has been proposed [3] and Josh Cartwright a few days ago prepared some code which implements those bindings [4]. This finally pushed me again to find some time to finish this task and review the code. Josh agreed to give me the ownership of this series to continue preparing them for mainline inclusion.

For more information please refer to the changlelog and links below.

[1]: http://lkml.kernel.org/g/1377527959-5080-1-git-send-email-m.szyprowski at samsung.com [2]: http://lkml.kernel.org/g/1381476448-14548-1-git-send-email-m.szyprowski at samsung.com [3]: http://lkml.kernel.org/g/20131030134702.19B57C402A0 at trevor.secretlab.ca [4]: http://thread.gmane.org/gmane.linux.documentation/19579

Changelog:

v6:
- removed the need for "#memory-region-cells" property
- fixed compilation issues on some systems
- some other minor code cleanups

v5: https://lkml.org/lkml/2014/2/21/147
- sliced main patch into several smaller patches on Grant's request
- fixed coding style issues pointed by Grant
- use node->phandle value directly instead of parsing properties manually

v4: https://lkml.org/lkml/2014/2/20/150
- dynamic allocations are processed after all static reservations has been done
- moved code for handling static reservations to drivers/of/fdt.c
- removed node matching by string comparison, now phandle values are used directly
- moved code for DMA and CMA handling directly to drivers/base/dma-{coherent,contiguous}.c
- added checks for proper #size-cells, #address-cells, ranges properties in /reserved-memory node
- even more code cleanup
- added init code for ARM64 and PowerPC

v3: http://article.gmane.org/gmane.linux.documentation/20169/
- refactored memory reservation code, created common code to parse reg, size, align, alloc-ranges properties
- added support for multiple tuples in 'reg' property
- memory is reserved regardless of presence of the driver for its compatible
- prepared arch specific hooks for memory reservation (defaults use memblock calls)
- removed node matching by string during device initialization
- CMA init code: added checks for required region alignment
- more code cleanup here and there

v2: http://thread.gmane.org/gmane.linux.documentation/19870/
- removed copying of the node name
- split shared-dma-pool handling into separate files (one for CMA and one for dma_declare_coherent based implementations) for making the code easier to understand
- added support for AMBA devices, changed prototypes to use struct decice instead of struct platform_device
- renamed some functions to better match other names used in drivers/of/
- restructured the rest of the code a bit for better readability
- added 'reusable' property to exmaple linux,cma node in documentation
- exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool' regions without 'reusable' property and CMA is used only for handling 'shared-dma-pool' regions with 'reusable' property.

v1: http://thread.gmane.org/gmane.linux.documentation/19579
- initial version prepared by Josh Cartwright

Summary:

Grant Likely (1):
of: document bindings for reserved-memory nodes

Marek Szyprowski (10):
drivers: of: add initialization code for static reserved memory
drivers: of: add initialization code for dynamic reserved memory
drivers: of: add support for custom reserved memory drivers
drivers: of: add automated assignment of reserved regions to client
devices
drivers: of: initialize and assign reserved memory to newly created
devices
drivers: dma-coherent: add initialization from device tree
drivers: dma-contiguous: add initialization from device tree
arm: add support for reserved memory defined by device tree
arm64: add support for reserved memory defined by device tree
powerpc: add support for reserved memory defined by device tree

 .../bindings/reserved-memory/reserved-memory.txt   |  136 ++++++++++
 arch/arm/Kconfig                                   |    1 +
 arch/arm/mm/init.c                                 |    2 +
 arch/arm64/Kconfig                                 |    1 +
 arch/arm64/mm/init.c                               |    1 +
 arch/powerpc/Kconfig                               |    1 +
 arch/powerpc/kernel/prom.c                         |    3 +
 drivers/base/dma-coherent.c                        |   40 +++
 drivers/base/dma-contiguous.c                      |  129 +++++++--
 drivers/of/Kconfig                                 |    6 +
 drivers/of/Makefile                                |    1 +
 drivers/of/fdt.c                                   |  140 ++++++++++
 drivers/of/of_reserved_mem.c                       |  287 ++++++++++++++++++++
 drivers/of/platform.c                              |    7 +
 include/asm-generic/vmlinux.lds.h                  |   11 +
 include/linux/of_fdt.h                             |    3 +
 include/linux/of_reserved_mem.h                    |   60 ++++
 17 files changed, 807 insertions(+), 22 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
 create mode 100644 drivers/of/of_reserved_mem.c
 create mode 100644 include/linux/of_reserved_mem.h

--
1.7.9.5

Hi Ben, Russell and Catalin,

I've got this series queued up, and I'd like to be ready to merge it in the next merge window. I'm going to queue it up in linux-next. If you have any concerns, please shout and it can be removed. I won't ask Linus to pull it without you giving the okay.

Quoted 120 lines · Marek Szyprowski

Hello again!

Here is another update of the support for reserved memory regions in device tree. I've fixes a few more minor issues pointed by Grant. See changelog for more details.

The initial code for this feature were posted here [1], merged as commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add initialization code for dma reserved memory") and later reverted by commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information, see [2]. Finally a new bindings has been proposed [3] and Josh Cartwright a few days ago prepared some code which implements those bindings [4]. This finally pushed me again to find some time to finish this task and review the code. Josh agreed to give me the ownership of this series to continue preparing them for mainline inclusion.

For more information please refer to the changlelog and links below.

[1]: http://lkml.kernel.org/g/1377527959-5080-1-git-send-email-m.szyprowski at samsung.com [2]: http://lkml.kernel.org/g/1381476448-14548-1-git-send-email-m.szyprowski at samsung.com [3]: http://lkml.kernel.org/g/20131030134702.19B57C402A0 at trevor.secretlab.ca [4]: http://thread.gmane.org/gmane.linux.documentation/19579

Changelog:

v6:
- removed the need for "#memory-region-cells" property
- fixed compilation issues on some systems
- some other minor code cleanups

v5: https://lkml.org/lkml/2014/2/21/147
- sliced main patch into several smaller patches on Grant's request
- fixed coding style issues pointed by Grant
- use node->phandle value directly instead of parsing properties manually

v4: https://lkml.org/lkml/2014/2/20/150
- dynamic allocations are processed after all static reservations has been done
- moved code for handling static reservations to drivers/of/fdt.c
- removed node matching by string comparison, now phandle values are used directly
- moved code for DMA and CMA handling directly to drivers/base/dma-{coherent,contiguous}.c
- added checks for proper #size-cells, #address-cells, ranges properties in /reserved-memory node
- even more code cleanup
- added init code for ARM64 and PowerPC

v3: http://article.gmane.org/gmane.linux.documentation/20169/
- refactored memory reservation code, created common code to parse reg, size, align, alloc-ranges properties
- added support for multiple tuples in 'reg' property
- memory is reserved regardless of presence of the driver for its compatible
- prepared arch specific hooks for memory reservation (defaults use memblock calls)
- removed node matching by string during device initialization
- CMA init code: added checks for required region alignment
- more code cleanup here and there

v2: http://thread.gmane.org/gmane.linux.documentation/19870/
- removed copying of the node name
- split shared-dma-pool handling into separate files (one for CMA and one for dma_declare_coherent based implementations) for making the code easier to understand
- added support for AMBA devices, changed prototypes to use struct decice instead of struct platform_device
- renamed some functions to better match other names used in drivers/of/
- restructured the rest of the code a bit for better readability
- added 'reusable' property to exmaple linux,cma node in documentation
- exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool' regions without 'reusable' property and CMA is used only for handling 'shared-dma-pool' regions with 'reusable' property.

v1: http://thread.gmane.org/gmane.linux.documentation/19579
- initial version prepared by Josh Cartwright

Summary:

Grant Likely (1):
of: document bindings for reserved-memory nodes

Marek Szyprowski (10):
drivers: of: add initialization code for static reserved memory
drivers: of: add initialization code for dynamic reserved memory
drivers: of: add support for custom reserved memory drivers
drivers: of: add automated assignment of reserved regions to client
devices
drivers: of: initialize and assign reserved memory to newly created
devices
drivers: dma-coherent: add initialization from device tree
drivers: dma-contiguous: add initialization from device tree
arm: add support for reserved memory defined by device tree
arm64: add support for reserved memory defined by device tree
powerpc: add support for reserved memory defined by device tree

 .../bindings/reserved-memory/reserved-memory.txt   |  136 ++++++++++
 arch/arm/Kconfig                                   |    1 +
 arch/arm/mm/init.c                                 |    2 +
 arch/arm64/Kconfig                                 |    1 +
 arch/arm64/mm/init.c                               |    1 +
 arch/powerpc/Kconfig                               |    1 +
 arch/powerpc/kernel/prom.c                         |    3 +
 drivers/base/dma-coherent.c                        |   40 +++
 drivers/base/dma-contiguous.c                      |  129 +++++++--
 drivers/of/Kconfig                                 |    6 +
 drivers/of/Makefile                                |    1 +
 drivers/of/fdt.c                                   |  140 ++++++++++
 drivers/of/of_reserved_mem.c                       |  287 ++++++++++++++++++++
 drivers/of/platform.c                              |    7 +
 include/asm-generic/vmlinux.lds.h                  |   11 +
 include/linux/of_fdt.h                             |    3 +
 include/linux/of_reserved_mem.h                    |   60 ++++
 17 files changed, 807 insertions(+), 22 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
 create mode 100644 drivers/of/of_reserved_mem.c
 create mode 100644 include/linux/of_reserved_mem.h

--
1.7.9.5