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. This split in initialization is also required for upcoming device tree support.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Acked-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/base/dma-contiguous.c | 210 +++++++++++++++++++++------------- include/asm-generic/dma-contiguous.h | 4 +- include/linux/dma-contiguous.h | 32 +++++- 3 files changed, 161 insertions(+), 85 deletions(-)

diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 0ca5442..085389c 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -39,7 +39,33 @@ struct cma { unsigned long *bitmap; };

-struct cma *dma_contiguous_default_area; +static DEFINE_MUTEX(cma_mutex); + +struct cma *dma_contiguous_def_area; +phys_addr_t dma_contiguous_def_base; + +static struct cma_area { + phys_addr_t base; + unsigned long size; + struct cma *cma; +} cma_areas[MAX_CMA_AREAS] __initdata; +static unsigned cma_area_count __initdata; + + +static struct cma_map { + phys_addr_t base; + struct device *dev; +} cma_maps[MAX_CMA_AREAS] __initdata; +static unsigned cma_map_count __initdata; + +static struct cma *cma_get_area(phys_addr_t base) +{ + int i; + for (i = 0; i < cma_area_count; i++) + if (cma_areas[i].base == base) + return cma_areas[i].cma; + return NULL; +}

#ifdef CONFIG_CMA_SIZE_MBYTES #define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES @@ -95,45 +121,6 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)

#endif

-/** - * dma_contiguous_reserve() - reserve area 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 - * called by arch specific code once the early allocator (memblock or bootmem) - * has been activated and all other subsystems have already allocated/reserved - * memory. - */ -void __init dma_contiguous_reserve(phys_addr_t limit) -{ - phys_addr_t selected_size = 0; - - pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); - - if (size_cmdline != -1) { - selected_size = size_cmdline; - } else { -#ifdef CONFIG_CMA_SIZE_SEL_MBYTES - selected_size = size_bytes; -#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) - selected_size = cma_early_percent_memory(); -#elif defined(CONFIG_CMA_SIZE_SEL_MIN) - selected_size = min(size_bytes, cma_early_percent_memory()); -#elif defined(CONFIG_CMA_SIZE_SEL_MAX) - selected_size = max(size_bytes, cma_early_percent_memory()); -#endif - } - - if (selected_size) { - 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); - } -}; - -static DEFINE_MUTEX(cma_mutex); - static __init int cma_activate_area(unsigned long base_pfn, unsigned long count) { unsigned long pfn = base_pfn; @@ -190,55 +177,73 @@ no_mem: return ERR_PTR(ret); }

-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 int __init cma_init_reserved_areas(void) +/** + * dma_contiguous_reserve() - reserve area 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 + * called by arch specific code once the early allocator (memblock or bootmem) + * has been activated and all other subsystems have already allocated/reserved + * memory. It reserves contiguous areas for global, device independent + * allocations and (optionally) all areas defined in device tree structures. + */ +void __init dma_contiguous_reserve(phys_addr_t limit) { - struct cma_reserved *r = cma_reserved; - unsigned i = cma_reserved_count; + phys_addr_t sel_size = 0;

- pr_debug("%s()\n", __func__); + pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);

- 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); + if (size_cmdline != -1) { + sel_size = size_cmdline; + } else { +#ifdef CONFIG_CMA_SIZE_SEL_MBYTES + sel_size = size_bytes; +#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) + sel_size = cma_early_percent_memory(); +#elif defined(CONFIG_CMA_SIZE_SEL_MIN) + sel_size = min(size_bytes, cma_early_percent_memory()); +#elif defined(CONFIG_CMA_SIZE_SEL_MAX) + sel_size = max(size_bytes, cma_early_percent_memory()); +#endif } - return 0; -} -core_initcall(cma_init_reserved_areas); + + if (sel_size) { + phys_addr_t base = 0; + pr_debug("%s: reserving %ld MiB for global area\n", __func__, + (unsigned long)sel_size / SZ_1M); + + if (dma_contiguous_reserve_area(sel_size, &base, limit) == 0) + dma_contiguous_def_base = base; + } +};

/** - * 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: Pointer to the base address of the reserved area, also used to return + * base address of the actually reserved area, optional, use pointer to + * 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. + * 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 *res_base, + phys_addr_t limit) { - struct cma_reserved *r = &cma_reserved[cma_reserved_count]; + phys_addr_t base = *res_base; 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 +261,7 @@ 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 +271,7 @@ 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 +282,11 @@ 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_areas[cma_area_count].base = base; + cma_areas[cma_area_count].size = size; + cma_area_count++; + *res_base = base; + pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, (unsigned long)base);

@@ -289,9 +295,55 @@ 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; +} + +/** + * dma_contiguous_add_device() - add device to custom contiguous reserved area + * @dev: Pointer to device structure. + * @base: Pointer to the base address of the reserved area returned by + * dma_contiguous_reserve_area() function, also used to return + * + * This function assigns the given device to the contiguous memory area + * reserved earlier by dma_contiguous_reserve_area() function. + */ +int __init dma_contiguous_add_device(struct device *dev, phys_addr_t base) +{ + if (cma_map_count == ARRAY_SIZE(cma_maps)) { + pr_err("Not enough slots for CMA reserved regions!\n"); + return -ENOSPC; + } + cma_maps[cma_map_count].dev = dev; + cma_maps[cma_map_count].base = base; + cma_map_count++; + return 0; }

+static int __init cma_init_reserved_areas(void) +{ + struct cma *cma; + int i; + + for (i = 0; i < cma_area_count; i++) { + phys_addr_t base = PFN_DOWN(cma_areas[i].base); + unsigned int count = cma_areas[i].size >> PAGE_SHIFT; + + cma = cma_create_area(base, count); + if (!IS_ERR(cma)) + cma_areas[i].cma = cma; + } + + dma_contiguous_def_area = cma_get_area(dma_contiguous_def_base); + + for (i = 0; i < cma_map_count; i++) { + cma = cma_get_area(cma_maps[i].base); + dev_set_cma_area(cma_maps[i].dev, cma); + } + + return 0; +} +core_initcall(cma_init_reserved_areas); + /** * dma_alloc_from_contiguous() - allocate pages from contiguous area * @dev: Pointer to device for which the allocation is performed. diff --git a/include/asm-generic/dma-contiguous.h b/include/asm-generic/dma-contiguous.h index 294b1e7..9071ef1 100644 --- a/include/asm-generic/dma-contiguous.h +++ b/include/asm-generic/dma-contiguous.h @@ -11,15 +11,13 @@ 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; + return dma_contiguous_def_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 diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h index 01b5c84..285b593 100644 --- a/include/linux/dma-contiguous.h +++ b/include/linux/dma-contiguous.h @@ -65,11 +65,37 @@ struct device; */ #define MAX_CMA_AREAS (1 + CONFIG_CMA_AREAS)

-extern struct cma *dma_contiguous_default_area; +extern struct cma *dma_contiguous_def_area;

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 dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t *res_base, + phys_addr_t limit); + +int dma_contiguous_add_device(struct device *dev, phys_addr_t base); + +/** + * 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) +{ + int ret; + ret = dma_contiguous_reserve_area(size, &base, limit); + if (ret == 0) + ret = dma_contiguous_add_device(dev, base); + return ret; +}

struct page *dma_alloc_from_contiguous(struct device *dev, int count, unsigned int order);

Add device tree support for contiguous memory regions defined in device tree. Initialization is done in 2 steps. First, the contiguous memory is reserved, what happens very early, when only flattened device tree is available. Then on device initialization the corresponding cma regions are assigned to device structures.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Acked-by: Kyungmin Park kyungmin.park@samsung.com --- Documentation/devicetree/bindings/memory.txt | 101 ++++++++++++++++++++++++++ arch/arm/boot/dts/skeleton.dtsi | 7 +- drivers/base/dma-contiguous.c | 72 ++++++++++++++++++ 3 files changed, 179 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/memory.txt

diff --git a/Documentation/devicetree/bindings/memory.txt b/Documentation/devicetree/bindings/memory.txt new file mode 100644 index 0000000..74e0476 --- /dev/null +++ b/Documentation/devicetree/bindings/memory.txt @@ -0,0 +1,101 @@ +* 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 folllowing node: + +memory { + reg = <(baseaddr1) (size1) + (baseaddr2) (size2) + ... + (baseaddrN) (sizeN)>; +}; + +baseaddrX: the base address of the defined memory bank +sizeX: the size of the defined memory bank + +More than one memory bank can be defined. + + +* Memory regions + +In /memory node one can create additional nodes describing particular +memory regions, usually 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 +wit the following convention: + +(name): region@(base-address) { + reg = <(baseaddr) (size)>; + (linux,contiguous-region); + (linux,default-contiguous-region); +}; + +name: an name given to the defined region. +base-address: the base address of the defined region. +size: the size of the memory region. +linux,contiguous-region: property indicating that the defined memory + region is used for contiguous memory allocations, + Linux specific (optional) +linux,default-contiguous-region: property indicating that the region + is the default region for all contiguous memory + allocations, Linux specific (optional) + + +* Device nodes + +Once the regions in the /memory node are defined, they can be assigned +to device some device nodes for their special use. The following +properties are defined: + +linux,contiguous-region = <&phandle>; + 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. 2 contiguous +regions are defined for Linux kernel, one default of all device drivers +(named contig_mem, placed at 0x72000000, 64MiB) and one dedicated to the +framebuffer device (named display_mem, placed at 0x78000000, 16MiB). The +display_mem region is then assigned to fb@12300000 device for contiguous +memory allocation with Linux kernel drivers. + +The reason for creating a separate region for framebuffer device is to +match the framebuffer address of from configuration done by bootloader, +so once Linux kernel drivers starts, no glitches on the displayed boot +logo appears. + +/ { + /* ... */ + memory { + reg = <0x40000000 0x10000000 + 0x50000000 0x10000000 + 0x60000000 0x10000000 + 0x70000000 0x10000000>; + + contig_mem: region@72000000 { + linux,contiguous-region; + linux,default-contiguous-region; + reg = <0x72000000 0x4000000>; + }; + + display_mem: region@78000000 { + linux,contiguous-region; + reg = <0x78000000 0x1000000>; + }; + }; + + fb@12300000 { + linux,contiguous-region = <&display_mem>; + status = "okay"; + }; +}; diff --git a/arch/arm/boot/dts/skeleton.dtsi b/arch/arm/boot/dts/skeleton.dtsi index b41d241..f9988cd 100644 --- a/arch/arm/boot/dts/skeleton.dtsi +++ b/arch/arm/boot/dts/skeleton.dtsi @@ -9,5 +9,10 @@ #size-cells = <1>; chosen { }; aliases { }; - memory { device_type = "memory"; reg = <0 0>; }; + memory { + #address-cells = <1>; + #size-cells = <1>; + device_type = "memory"; + reg = <0 0>; + }; }; diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 085389c..5761f73 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -24,6 +24,9 @@

#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/mutex.h> #include <linux/page-isolation.h> @@ -177,6 +180,35 @@ no_mem: return ERR_PTR(ret); }

+/*****************************************************************************/ + +#ifdef CONFIG_OF +int __init cma_fdt_scan(unsigned long node, const char *uname, + int depth, void *data) +{ + phys_addr_t base, size; + unsigned long len; + __be32 *prop; + + if (strncmp(uname, "region@", 7) != 0 || depth != 2 || + !of_get_flat_dt_prop(node, "contiguous-region", NULL)) + return 0; + + prop = of_get_flat_dt_prop(node, "reg", &len); + if (!prop || (len != 2 * sizeof(unsigned long))) + return 0; + + base = be32_to_cpu(prop[0]); + size = be32_to_cpu(prop[1]); + + pr_info("Found %s, memory base %lx, size %ld MiB\n", uname, + (unsigned long)base, (unsigned long)size / SZ_1M); + dma_contiguous_reserve_area(size, &base, 0); + + return 0; +} +#endif + /** * dma_contiguous_reserve() - reserve area for contiguous memory handling * @limit: End address of the reserved memory (optional, 0 for any). @@ -215,6 +247,9 @@ void __init dma_contiguous_reserve(phys_addr_t limit) if (dma_contiguous_reserve_area(sel_size, &base, limit) == 0) dma_contiguous_def_base = base; } +#ifdef CONFIG_OF + of_scan_flat_dt(cma_fdt_scan, NULL); +#endif };

/** @@ -319,6 +354,40 @@ int __init dma_contiguous_add_device(struct device *dev, phys_addr_t base) return 0; }

+#ifdef CONFIG_OF +static void cma_assign_device_from_dt(struct device *dev) +{ + struct device_node *node; + struct cma *cma; + u32 value; + + node = of_parse_phandle(dev->of_node, "linux,contiguous-region", 0); + if (!node) + return; + if (of_property_read_u32(node, "reg", &value) && !value) + return; + cma = cma_get_area(value); + if (!cma) + return; + + dev_set_cma_area(dev, cma); + pr_info("Assigned CMA region at %lx to %s device\n", (unsigned long)value, dev_name(dev)); +} + +static int cma_device_init_notifier_call(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct device *dev = data; + if (event == BUS_NOTIFY_ADD_DEVICE && dev->of_node) + cma_assign_device_from_dt(dev); + return NOTIFY_DONE; +} + +static struct notifier_block cma_dev_init_nb = { + .notifier_call = cma_device_init_notifier_call, +}; +#endif + static int __init cma_init_reserved_areas(void) { struct cma *cma; @@ -340,6 +409,9 @@ static int __init cma_init_reserved_areas(void) dev_set_cma_area(cma_maps[i].dev, cma); }

+#ifdef CONFIG_OF + bus_register_notifier(&platform_bus_type, &cma_dev_init_nb); +#endif return 0; } core_initcall(cma_init_reserved_areas);