From a2547380393ac82c659b40182b0da8d05a8365f3 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 29 Jul 2013 14:31:45 +0200 Subject: drivers: dma-contiguous: clean source code and prepare for device tree This patch cleans the initialization of dma contiguous framework. The all-in-one dma_declare_contiguous() function is now separated into dma_contiguous_reserve_area() which only steals the the memory from memblock allocator and dma_contiguous_add_device() function, which assigns given device to the specified reserved memory area. This improves the flexibility in defining contiguous memory areas and assigning device to them, because now it is possible to assign more than one device to the given contiguous memory area. Such split in initialization procedure is also required for upcoming device tree support. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Acked-by: Michal Nazarewicz Acked-by: Tomasz Figa --- arch/arm/include/asm/dma-contiguous.h | 1 - arch/x86/include/asm/dma-contiguous.h | 1 - drivers/base/dma-contiguous.c | 119 +++++++++++++--------------------- include/asm-generic/dma-contiguous.h | 28 -------- include/linux/device.h | 2 +- include/linux/dma-contiguous.h | 62 +++++++++++++++++- 6 files changed, 105 insertions(+), 108 deletions(-) delete mode 100644 include/asm-generic/dma-contiguous.h diff --git a/arch/arm/include/asm/dma-contiguous.h b/arch/arm/include/asm/dma-contiguous.h index e072bb2ba1b1..4f8e9e5514b1 100644 --- a/arch/arm/include/asm/dma-contiguous.h +++ b/arch/arm/include/asm/dma-contiguous.h @@ -5,7 +5,6 @@ #ifdef CONFIG_DMA_CMA #include -#include void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size); diff --git a/arch/x86/include/asm/dma-contiguous.h b/arch/x86/include/asm/dma-contiguous.h index c09241659971..b4b38bacb404 100644 --- a/arch/x86/include/asm/dma-contiguous.h +++ b/arch/x86/include/asm/dma-contiguous.h @@ -4,7 +4,6 @@ #ifdef __KERNEL__ #include -#include static inline void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { } diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 0ca54421ce97..99802d6f3c60 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -96,7 +96,7 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) #endif /** - * dma_contiguous_reserve() - reserve area for contiguous memory handling + * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling * @limit: End address of the reserved memory (optional, 0 for any). * * This function reserves memory from early allocator. It should be @@ -124,22 +124,29 @@ void __init dma_contiguous_reserve(phys_addr_t limit) #endif } - if (selected_size) { + if (selected_size && !dma_contiguous_default_area) { pr_debug("%s: reserving %ld MiB for global area\n", __func__, (unsigned long)selected_size / SZ_1M); - dma_declare_contiguous(NULL, selected_size, 0, limit); + dma_contiguous_reserve_area(selected_size, 0, limit, + &dma_contiguous_default_area); } }; static DEFINE_MUTEX(cma_mutex); -static __init int cma_activate_area(unsigned long base_pfn, unsigned long count) +static int __init cma_activate_area(struct cma *cma) { - unsigned long pfn = base_pfn; - unsigned i = count >> pageblock_order; + int bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long); + unsigned long base_pfn = cma->base_pfn, pfn = base_pfn; + unsigned i = cma->count >> pageblock_order; struct zone *zone; + cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + + if (!cma->bitmap) + return -ENOMEM; + WARN_ON_ONCE(!pfn_valid(pfn)); zone = page_zone(pfn_to_page(pfn)); @@ -153,92 +160,53 @@ static __init int cma_activate_area(unsigned long base_pfn, unsigned long count) } init_cma_reserved_pageblock(pfn_to_page(base_pfn)); } while (--i); - return 0; -} - -static __init struct cma *cma_create_area(unsigned long base_pfn, - unsigned long count) -{ - int bitmap_size = BITS_TO_LONGS(count) * sizeof(long); - struct cma *cma; - int ret = -ENOMEM; - - pr_debug("%s(base %08lx, count %lx)\n", __func__, base_pfn, count); - - cma = kmalloc(sizeof *cma, GFP_KERNEL); - if (!cma) - return ERR_PTR(-ENOMEM); - - cma->base_pfn = base_pfn; - cma->count = count; - cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!cma->bitmap) - goto no_mem; - - ret = cma_activate_area(base_pfn, count); - if (ret) - goto error; - - pr_debug("%s: returned %p\n", __func__, (void *)cma); - return cma; - -error: - kfree(cma->bitmap); -no_mem: - kfree(cma); - return ERR_PTR(ret); + return 0; } -static struct cma_reserved { - phys_addr_t start; - unsigned long size; - struct device *dev; -} cma_reserved[MAX_CMA_AREAS] __initdata; -static unsigned cma_reserved_count __initdata; +static struct cma cma_areas[MAX_CMA_AREAS]; +static unsigned cma_area_count; static int __init cma_init_reserved_areas(void) { - struct cma_reserved *r = cma_reserved; - unsigned i = cma_reserved_count; - - pr_debug("%s()\n", __func__); + int i; - for (; i; --i, ++r) { - struct cma *cma; - cma = cma_create_area(PFN_DOWN(r->start), - r->size >> PAGE_SHIFT); - if (!IS_ERR(cma)) - dev_set_cma_area(r->dev, cma); + for (i = 0; i < cma_area_count; i++) { + int ret = cma_activate_area(&cma_areas[i]); + if (ret) + return ret; } + return 0; } core_initcall(cma_init_reserved_areas); /** - * dma_declare_contiguous() - reserve area for contiguous memory handling - * for particular device - * @dev: Pointer to device structure. - * @size: Size of the reserved memory. - * @base: Start address of the reserved memory (optional, 0 for any). + * dma_contiguous_reserve_area() - reserve custom contiguous area + * @size: Size of the reserved area (in bytes), + * @base: Base address of the reserved area optional, use 0 for any * @limit: End address of the reserved memory (optional, 0 for any). + * @res_cma: Pointer to store the created cma region. * - * This function reserves memory for specified device. It should be - * called by board specific code when early allocator (memblock or bootmem) - * is still activate. + * This function reserves memory from early allocator. It should be + * called by arch specific code once the early allocator (memblock or bootmem) + * has been activated and all other subsystems have already allocated/reserved + * memory. This function allows to create custom reserved areas for specific + * devices. */ -int __init dma_declare_contiguous(struct device *dev, phys_addr_t size, - phys_addr_t base, phys_addr_t limit) +int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, + phys_addr_t limit, struct cma **res_cma) { - struct cma_reserved *r = &cma_reserved[cma_reserved_count]; + struct cma *cma = &cma_areas[cma_area_count]; phys_addr_t alignment; + int ret = 0; pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__, (unsigned long)size, (unsigned long)base, (unsigned long)limit); /* Sanity checks */ - if (cma_reserved_count == ARRAY_SIZE(cma_reserved)) { + if (cma_area_count == ARRAY_SIZE(cma_areas)) { pr_err("Not enough slots for CMA reserved regions!\n"); return -ENOSPC; } @@ -256,7 +224,7 @@ int __init dma_declare_contiguous(struct device *dev, phys_addr_t size, if (base) { if (memblock_is_region_reserved(base, size) || memblock_reserve(base, size) < 0) { - base = -EBUSY; + ret = -EBUSY; goto err; } } else { @@ -266,7 +234,7 @@ int __init dma_declare_contiguous(struct device *dev, phys_addr_t size, */ phys_addr_t addr = __memblock_alloc_base(size, alignment, limit); if (!addr) { - base = -ENOMEM; + ret = -ENOMEM; goto err; } else { base = addr; @@ -277,10 +245,11 @@ int __init dma_declare_contiguous(struct device *dev, phys_addr_t size, * Each reserved area must be initialised later, when more kernel * subsystems (like slab allocator) are available. */ - r->start = base; - r->size = size; - r->dev = dev; - cma_reserved_count++; + cma->base_pfn = PFN_DOWN(base); + cma->count = size >> PAGE_SHIFT; + *res_cma = cma; + cma_area_count++; + pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, (unsigned long)base); @@ -289,7 +258,7 @@ int __init dma_declare_contiguous(struct device *dev, phys_addr_t size, return 0; err: pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M); - return base; + return ret; } /** diff --git a/include/asm-generic/dma-contiguous.h b/include/asm-generic/dma-contiguous.h deleted file mode 100644 index 294b1e755ab2..000000000000 --- a/include/asm-generic/dma-contiguous.h +++ /dev/null @@ -1,28 +0,0 @@ -#ifndef ASM_DMA_CONTIGUOUS_H -#define ASM_DMA_CONTIGUOUS_H - -#ifdef __KERNEL__ -#ifdef CONFIG_CMA - -#include -#include - -static inline struct cma *dev_get_cma_area(struct device *dev) -{ - if (dev && dev->cma_area) - return dev->cma_area; - return dma_contiguous_default_area; -} - -static inline void dev_set_cma_area(struct device *dev, struct cma *cma) -{ - if (dev) - dev->cma_area = cma; - if (!dev && !dma_contiguous_default_area) - dma_contiguous_default_area = cma; -} - -#endif -#endif - -#endif diff --git a/include/linux/device.h b/include/linux/device.h index bcf8c0d4cd98..9200cfd75f15 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -711,7 +711,7 @@ struct device { struct dma_coherent_mem *dma_mem; /* internal for coherent mem override */ -#ifdef CONFIG_CMA +#ifdef CONFIG_DMA_CMA struct cma *cma_area; /* contiguous memory area for dma allocations */ #endif diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h index 00141d3325fe..3b28f937d959 100644 --- a/include/linux/dma-contiguous.h +++ b/include/linux/dma-contiguous.h @@ -67,9 +67,53 @@ struct device; extern struct cma *dma_contiguous_default_area; +static inline struct cma *dev_get_cma_area(struct device *dev) +{ + if (dev && dev->cma_area) + return dev->cma_area; + return dma_contiguous_default_area; +} + +static inline void dev_set_cma_area(struct device *dev, struct cma *cma) +{ + if (dev) + dev->cma_area = cma; +} + +static inline void dma_contiguous_set_default(struct cma *cma) +{ + dma_contiguous_default_area = cma; +} + void dma_contiguous_reserve(phys_addr_t addr_limit); -int dma_declare_contiguous(struct device *dev, phys_addr_t size, - phys_addr_t base, phys_addr_t limit); + +int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, + phys_addr_t limit, struct cma **res_cma); + +/** + * dma_declare_contiguous() - reserve area for contiguous memory handling + * for particular device + * @dev: Pointer to device structure. + * @size: Size of the reserved memory. + * @base: Start address of the reserved memory (optional, 0 for any). + * @limit: End address of the reserved memory (optional, 0 for any). + * + * This function reserves memory for specified device. It should be + * called by board specific code when early allocator (memblock or bootmem) + * is still activate. + */ + +static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size, + phys_addr_t base, phys_addr_t limit) +{ + struct cma *cma; + int ret; + ret = dma_contiguous_reserve_area(size, base, limit, &cma); + if (ret == 0) + dev_set_cma_area(dev, cma); + + return ret; +} struct page *dma_alloc_from_contiguous(struct device *dev, int count, unsigned int order); @@ -80,8 +124,22 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, #define MAX_CMA_AREAS (0) +static inline struct cma *dev_get_cma_area(struct device *dev) +{ + return NULL; +} + +static inline void dev_set_cma_area(struct device *dev, struct cma *cma) { } + +static inline void dma_contiguous_set_default(struct cma *cma) { } + static inline void dma_contiguous_reserve(phys_addr_t limit) { } +static inline int dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, + phys_addr_t limit, struct cma **res_cma) { + return -ENOSYS; +} + static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size, phys_addr_t base, phys_addr_t limit) -- cgit v1.2.3 From 57d74bcf3072b65bde5aa540cedc976a75c48e5c Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 26 Aug 2013 14:41:56 +0200 Subject: drivers: of: add function to scan fdt nodes given by path Add a function to scan the flattened device-tree starting from the node given by the path. It is used to extract information (like reserved memory), which is required on early boot before we can unflatten the tree. Signed-off-by: Marek Szyprowski Acked-by: Michal Nazarewicz Acked-by: Tomasz Figa Reviewed-by: Rob Herring --- drivers/of/fdt.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 3 ++ 2 files changed, 79 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 6bb7cf2de556..585b1a67cfbe 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -543,6 +543,82 @@ int __init of_flat_dt_match(unsigned long node, const char *const *compat) return of_fdt_match(initial_boot_params, node, compat); } +struct fdt_scan_status { + const char *name; + int namelen; + int depth; + int found; + int (*iterator)(unsigned long node, const char *uname, int depth, void *data); + void *data; +}; + +/** + * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function + */ +static int __init fdt_scan_node_by_path(unsigned long node, const char *uname, + int depth, void *data) +{ + struct fdt_scan_status *st = data; + + /* + * if scan at the requested fdt node has been completed, + * return -ENXIO to abort further scanning + */ + if (depth <= st->depth) + return -ENXIO; + + /* requested fdt node has been found, so call iterator function */ + if (st->found) + return st->iterator(node, uname, depth, st->data); + + /* check if scanning automata is entering next level of fdt nodes */ + if (depth == st->depth + 1 && + strncmp(st->name, uname, st->namelen) == 0 && + uname[st->namelen] == 0) { + st->depth += 1; + if (st->name[st->namelen] == 0) { + st->found = 1; + } else { + const char *next = st->name + st->namelen + 1; + st->name = next; + st->namelen = strcspn(next, "/"); + } + return 0; + } + + /* scan next fdt node */ + return 0; +} + +/** + * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each + * child of the given path. + * @path: path to start searching for children + * @it: callback function + * @data: context data pointer + * + * This function is used to scan the flattened device-tree starting from the + * node given by path. It is used to extract information (like reserved + * memory), which is required on ealy boot before we can unflatten the tree. + */ +int __init of_scan_flat_dt_by_path(const char *path, + int (*it)(unsigned long node, const char *name, int depth, void *data), + void *data) +{ + struct fdt_scan_status st = {path, 0, -1, 0, it, data}; + int ret = 0; + + if (initial_boot_params) + ret = of_scan_flat_dt(fdt_scan_node_by_path, &st); + + if (!st.found) + return -ENOENT; + else if (ret == -ENXIO) /* scan has been completed */ + return 0; + else + return ret; +} + #ifdef CONFIG_BLK_DEV_INITRD /** * early_init_dt_check_for_initrd - Decode initrd location from flat tree diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index ed136ad698ce..19f26f8d2202 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -90,6 +90,9 @@ extern void *of_get_flat_dt_prop(unsigned long node, const char *name, extern int of_flat_dt_is_compatible(unsigned long node, const char *name); extern int of_flat_dt_match(unsigned long node, const char *const *matches); extern unsigned long of_get_flat_dt_root(void); +extern int of_scan_flat_dt_by_path(const char *path, + int (*it)(unsigned long node, const char *name, int depth, void *data), + void *data); extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, int depth, void *data); -- cgit v1.2.3 From 9d8eab7af79cb4ce2de5de39f82c455b1f796963 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 26 Aug 2013 14:43:10 +0200 Subject: drivers: of: add initialization code for dma reserved memory This patch adds device tree support for contiguous and reserved memory regions defined in device tree. Large 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) or mapping with special properties can be created (for CMA blocks). This all happens before device tree structures are unflattened, so we need to get reserved memory layout directly from fdt. Later, those reserved memory regions are assigned to devices on each device structure initialization. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Acked-by: Michal Nazarewicz Acked-by: Tomasz Figa Acked-by: Stephen Warren Reviewed-by: Rob Herring --- Documentation/devicetree/bindings/memory.txt | 168 +++++++++++++++++++++++++ drivers/of/Kconfig | 6 + drivers/of/Makefile | 1 + drivers/of/of_reserved_mem.c | 175 +++++++++++++++++++++++++++ drivers/of/platform.c | 4 + include/linux/of_reserved_mem.h | 14 +++ 6 files changed, 368 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory.txt create mode 100644 drivers/of/of_reserved_mem.c create mode 100644 include/linux/of_reserved_mem.h diff --git a/Documentation/devicetree/bindings/memory.txt b/Documentation/devicetree/bindings/memory.txt new file mode 100644 index 000000000000..eb2469365593 --- /dev/null +++ b/Documentation/devicetree/bindings/memory.txt @@ -0,0 +1,168 @@ +*** 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>; + }; +}; diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 80e5c13b930d..730965157b2c 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -80,4 +80,10 @@ config OF_MTD 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 diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 1f9c0c492ef9..e7e3322679a8 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -10,3 +10,4 @@ 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 diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c new file mode 100644 index 000000000000..a754b84ba016 --- /dev/null +++ b/drivers/of/of_reserved_mem.c @@ -0,0 +1,175 @@ +/* + * Device tree based initialization code for reserved memory. + * + * Copyright (c) 2013 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * Author: Marek Szyprowski + * + * 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 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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); +} diff --git a/drivers/of/platform.c b/drivers/of/platform.c index e0a6514ab46c..eeca8a596973 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -21,6 +21,7 @@ #include #include #include +#include #include const struct of_device_id of_default_bus_match_table[] = { @@ -218,6 +219,8 @@ struct platform_device *of_platform_device_create_pdata( 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 @@ -225,6 +228,7 @@ struct platform_device *of_platform_device_create_pdata( if (of_device_add(dev) != 0) { platform_device_put(dev); + of_reserved_mem_device_release(&dev->dev); return NULL; } diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h new file mode 100644 index 000000000000..c84128255814 --- /dev/null +++ b/include/linux/of_reserved_mem.h @@ -0,0 +1,14 @@ +#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 */ -- cgit v1.2.3 From 10bcdfb8ba24760f715f0a700c3812747eddddf5 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Fri, 9 Aug 2013 13:01:08 +0200 Subject: ARM: init: add support for reserved memory defined by device tree Enable reserved memory initialization from device tree. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Acked-by: Michal Nazarewicz Acked-by: Tomasz Figa --- arch/arm/mm/init.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 15225d829d71..6a2fe4453eee 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -377,6 +378,8 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc) if (mdesc->reserve) mdesc->reserve(); + early_init_dt_scan_reserved_mem(); + /* * reserve memory for DMA contigouos allocations, * must come from DMA area inside low memory -- cgit v1.2.3