+++ /dev/null
-*** Memory binding ***
-
-The /memory node provides basic information about the address and size
-of the physical memory. This node is usually filled or updated by the
-bootloader, depending on the actual memory configuration of the given
-hardware.
-
-The memory layout is described by the following node:
-
-/ {
- #address-cells = <(n)>;
- #size-cells = <(m)>;
- memory {
- device_type = "memory";
- reg = <(baseaddr1) (size1)
- (baseaddr2) (size2)
- ...
- (baseaddrN) (sizeN)>;
- };
- ...
-};
-
-A memory node follows the typical device tree rules for "reg" property:
-n: number of cells used to store base address value
-m: number of cells used to store size value
-baseaddrX: defines a base address of the defined memory bank
-sizeX: the size of the defined memory bank
-
-
-More than one memory bank can be defined.
-
-
-*** Reserved memory regions ***
-
-In /memory/reserved-memory node 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. A good example are contiguous memory allocations or
-memory sharing with other operating system on the same hardware board.
-Those special memory regions might depend on the board configuration and
-devices used on the target system.
-
-Parameters for each memory region can be encoded into the device tree
-with the following convention:
-
-[(label):] (name) {
- compatible = "linux,contiguous-memory-region", "reserved-memory-region";
- reg = <(address) (size)>;
- (linux,default-contiguous-region);
-};
-
-compatible: one or more of:
- - "linux,contiguous-memory-region" - enables binding of this
- region to Contiguous Memory Allocator (special region for
- contiguous memory allocations, shared with movable system
- memory, Linux kernel-specific).
- - "reserved-memory-region" - compatibility is defined, given
- region is assigned for exclusive usage for by the respective
- devices.
-
-reg: standard property defining the base address and size of
- the memory region
-
-linux,default-contiguous-region: property indicating that the region
- is the default region for all contiguous memory
- allocations, Linux specific (optional)
-
-It is optional to specify the base address, so if one wants to use
-autoconfiguration of the base address, '0' can be specified as a base
-address in the 'reg' property.
-
-The /memory/reserved-memory node must contain the same #address-cells
-and #size-cells value as the root node.
-
-
-*** Device node's properties ***
-
-Once regions in the /memory/reserved-memory node have been defined, they
-may be referenced by other device nodes. Bindings that wish to reference
-memory regions should explicitly document their use of the following
-property:
-
-memory-region = <&phandle_to_defined_region>;
-
-This property indicates that the device driver should use the memory
-region pointed by the given phandle.
-
-
-*** Example ***
-
-This example defines a memory consisting of 4 memory banks. 3 contiguous
-regions are defined for Linux kernel, one default of all device drivers
-(named contig_mem, placed at 0x72000000, 64MiB), one dedicated to the
-framebuffer device (labelled display_mem, placed at 0x78000000, 8MiB)
-and one for multimedia processing (labelled multimedia_mem, placed at
-0x77000000, 64MiB). 'display_mem' region is then assigned to fb@12300000
-device for DMA memory allocations (Linux kernel drivers will use CMA is
-available or dma-exclusive usage otherwise). 'multimedia_mem' is
-assigned to scaler@12500000 and codec@12600000 devices for contiguous
-memory allocations when CMA driver is enabled.
-
-The reason for creating a separate region for framebuffer device is to
-match the framebuffer base address to the one configured by bootloader,
-so once Linux kernel drivers starts no glitches on the displayed boot
-logo appears. Scaller and codec drivers should share the memory
-allocations.
-
-/ {
- #address-cells = <1>;
- #size-cells = <1>;
-
- /* ... */
-
- memory {
- reg = <0x40000000 0x10000000
- 0x50000000 0x10000000
- 0x60000000 0x10000000
- 0x70000000 0x10000000>;
-
- reserved-memory {
- #address-cells = <1>;
- #size-cells = <1>;
-
- /*
- * global autoconfigured region for contiguous allocations
- * (used only with Contiguous Memory Allocator)
- */
- contig_region@0 {
- compatible = "linux,contiguous-memory-region";
- reg = <0x0 0x4000000>;
- linux,default-contiguous-region;
- };
-
- /*
- * special region for framebuffer
- */
- display_region: region@78000000 {
- compatible = "linux,contiguous-memory-region", "reserved-memory-region";
- reg = <0x78000000 0x800000>;
- };
-
- /*
- * special region for multimedia processing devices
- */
- multimedia_region: region@77000000 {
- compatible = "linux,contiguous-memory-region";
- reg = <0x77000000 0x4000000>;
- };
- };
- };
-
- /* ... */
-
- fb0: fb@12300000 {
- status = "okay";
- memory-region = <&display_region>;
- };
-
- scaler: scaler@12500000 {
- status = "okay";
- memory-region = <&multimedia_region>;
- };
-
- codec: codec@12600000 {
- status = "okay";
- memory-region = <&multimedia_region>;
- };
-};
depends on MTD
def_bool y
-config OF_RESERVED_MEM
- depends on OF_FLATTREE && (DMA_CMA || (HAVE_GENERIC_DMA_COHERENT && HAVE_MEMBLOCK))
- def_bool y
- help
- Initialization code for DMA reserved memory
-
endmenu # OF
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
+++ /dev/null
-/*
- * Device tree based initialization code for reserved memory.
- *
- * Copyright (c) 2013 Samsung Electronics Co., Ltd.
- * http://www.samsung.com
- * Author: Marek Szyprowski <m.szyprowski@samsung.com>
- *
- * 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/memblock.h>
-#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/mm_types.h>
-#include <linux/dma-contiguous.h>
-#include <linux/dma-mapping.h>
-#include <linux/of_reserved_mem.h>
-
-#define MAX_RESERVED_REGIONS 16
-struct reserved_mem {
- phys_addr_t base;
- unsigned long size;
- struct cma *cma;
- char name[32];
-};
-static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
-static int reserved_mem_count;
-
-static int __init fdt_scan_reserved_mem(unsigned long node, const char *uname,
- int depth, void *data)
-{
- struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
- phys_addr_t base, size;
- int is_cma, is_reserved;
- unsigned long len;
- const char *status;
- __be32 *prop;
-
- is_cma = IS_ENABLED(CONFIG_DMA_CMA) &&
- of_flat_dt_is_compatible(node, "linux,contiguous-memory-region");
- is_reserved = of_flat_dt_is_compatible(node, "reserved-memory-region");
-
- if (!is_reserved && !is_cma) {
- /* ignore node and scan next one */
- return 0;
- }
-
- status = of_get_flat_dt_prop(node, "status", &len);
- if (status && strcmp(status, "okay") != 0) {
- /* ignore disabled node nad scan next one */
- return 0;
- }
-
- prop = of_get_flat_dt_prop(node, "reg", &len);
- if (!prop || (len < (dt_root_size_cells + dt_root_addr_cells) *
- sizeof(__be32))) {
- pr_err("Reserved mem: node %s, incorrect \"reg\" property\n",
- uname);
- /* ignore node and scan next one */
- return 0;
- }
- base = dt_mem_next_cell(dt_root_addr_cells, &prop);
- size = dt_mem_next_cell(dt_root_size_cells, &prop);
-
- if (!size) {
- /* ignore node and scan next one */
- return 0;
- }
-
- pr_info("Reserved mem: found %s, memory base %lx, size %ld MiB\n",
- uname, (unsigned long)base, (unsigned long)size / SZ_1M);
-
- if (reserved_mem_count == ARRAY_SIZE(reserved_mem))
- return -ENOSPC;
-
- rmem->base = base;
- rmem->size = size;
- strlcpy(rmem->name, uname, sizeof(rmem->name));
-
- if (is_cma) {
- struct cma *cma;
- if (dma_contiguous_reserve_area(size, base, 0, &cma) == 0) {
- rmem->cma = cma;
- reserved_mem_count++;
- if (of_get_flat_dt_prop(node,
- "linux,default-contiguous-region",
- NULL))
- dma_contiguous_set_default(cma);
- }
- } else if (is_reserved) {
- if (memblock_remove(base, size) == 0)
- reserved_mem_count++;
- else
- pr_err("Failed to reserve memory for %s\n", uname);
- }
-
- return 0;
-}
-
-static struct reserved_mem *get_dma_memory_region(struct device *dev)
-{
- struct device_node *node;
- const char *name;
- int i;
-
- node = of_parse_phandle(dev->of_node, "memory-region", 0);
- if (!node)
- return NULL;
-
- name = kbasename(node->full_name);
- for (i = 0; i < reserved_mem_count; i++)
- if (strcmp(name, reserved_mem[i].name) == 0)
- 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 *region = get_dma_memory_region(dev);
- if (!region)
- return;
-
- if (region->cma) {
- dev_set_cma_area(dev, region->cma);
- pr_info("Assigned CMA %s to %s device\n", region->name,
- dev_name(dev));
- } else {
- if (dma_declare_coherent_memory(dev, region->base, region->base,
- region->size, DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE) != 0)
- pr_info("Declared reserved memory %s to %s device\n",
- region->name, dev_name(dev));
- }
-}
-
-/**
- * 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 *region = get_dma_memory_region(dev);
- if (!region && !region->cma)
- dma_release_declared_memory(dev);
-}
-
-/**
- * early_init_dt_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 (memblock) has been activated and all other
- * subsystems have already allocated/reserved memory.
- */
-void __init early_init_dt_scan_reserved_mem(void)
-{
- of_scan_flat_dt_by_path("/memory/reserved-memory",
- fdt_scan_reserved_mem, NULL);
-}
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
-#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
const struct of_device_id of_default_bus_match_table[] = {
dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;
- of_reserved_mem_device_init(&dev->dev);
-
/* We do not fill the DMA ops for platform devices by default.
* This is currently the responsibility of the platform code
* to do such, possibly using a device notifier
if (of_device_add(dev) != 0) {
platform_device_put(dev);
- of_reserved_mem_device_release(&dev->dev);
return NULL;
}
+++ /dev/null
-#ifndef __OF_RESERVED_MEM_H
-#define __OF_RESERVED_MEM_H
-
-#ifdef CONFIG_OF_RESERVED_MEM
-void of_reserved_mem_device_init(struct device *dev);
-void of_reserved_mem_device_release(struct device *dev);
-void early_init_dt_scan_reserved_mem(void);
-#else
-static inline void of_reserved_mem_device_init(struct device *dev) { }
-static inline void of_reserved_mem_device_release(struct device *dev) { }
-static inline void early_init_dt_scan_reserved_mem(void) { }
-#endif
-
-#endif /* __OF_RESERVED_MEM_H */
git.samba.org / sfrench / cifs-2.6.git / commitdiff