// SPDX-License-Identifier: GPL-2.0+/* * Contiguous Memory Allocator for DMA mapping framework * Copyright (c) 2010-2011 by Samsung Electronics. * Written by: * Marek Szyprowski <m.szyprowski@samsung.com> * Michal Nazarewicz <mina86@mina86.com> * * Contiguous Memory Allocator * * The Contiguous Memory Allocator (CMA) makes it possible to * allocate big contiguous chunks of memory after the system has * booted. * * Why is it needed? * * Various devices on embedded systems have no scatter-getter and/or * IO map support and require contiguous blocks of memory to * operate. They include devices such as cameras, hardware video * coders, etc. * * Such devices often require big memory buffers (a full HD frame * is, for instance, more than 2 mega pixels large, i.e. more than 6 * MB of memory), which makes mechanisms such as kmalloc() or * alloc_page() ineffective. * * At the same time, a solution where a big memory region is * reserved for a device is suboptimal since often more memory is * reserved then strictly required and, moreover, the memory is * inaccessible to page system even if device drivers don't use it. * * CMA tries to solve this issue by operating on memory regions * where only movable pages can be allocated from. This way, kernel * can use the memory for pagecache and when device driver requests * it, allocated pages can be migrated. */ #define pr_fmt(fmt) "cma: " fmt #include <asm/page.h> #include <linux/memblock.h>#include <linux/err.h>#include <linux/sizes.h>#include <linux/dma-map-ops.h>#include <linux/cma.h>#include <linux/nospec.h> #ifdef CONFIG_CMA_SIZE_MBYTES#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES#else#define CMA_SIZE_MBYTES 0#endif static struct cma *dma_contiguous_areas[MAX_CMA_AREAS];static unsigned int dma_contiguous_areas_num; static int dma_contiguous_insert_area(struct cma *cma){ if (dma_contiguous_areas_num >= ARRAY_SIZE(dma_contiguous_areas)) return -EINVAL; dma_contiguous_areas[dma_contiguous_areas_num++] = cma; return 0;} /** * dma_contiguous_get_area_by_idx() - Get contiguous area at given index * @idx: index of the area we query * * Queries for the contiguous area located at index @idx. * * Returns: * A pointer to the requested contiguous area, or NULL otherwise. */struct cma *dma_contiguous_get_area_by_idx(unsigned int idx){ if (idx >= dma_contiguous_areas_num) return NULL; return dma_contiguous_areas[idx];}EXPORT_SYMBOL_GPL(dma_contiguous_get_area_by_idx); static struct cma *dma_contiguous_default_area; /* * Default global CMA area size can be defined in kernel's .config. * This is useful mainly for distro maintainers to create a kernel * that works correctly for most supported systems. * The size can be set in bytes or as a percentage of the total memory * in the system. * * Users, who want to set the size of global CMA area for their system * should use cma= kernel parameter. */#define size_bytes ((phys_addr_t)CMA_SIZE_MBYTES * SZ_1M)static phys_addr_t size_cmdline __initdata = -1;static phys_addr_t base_cmdline __initdata;static phys_addr_t limit_cmdline __initdata; static int __init early_cma(char *p){ if (!p) { pr_err("Config string not provided\n"); return -EINVAL; } size_cmdline = memparse(p, &p); if (*p != '@') return 0; base_cmdline = memparse(p + 1, &p); if (*p != '-') { limit_cmdline = base_cmdline + size_cmdline; return 0; } limit_cmdline = memparse(p + 1, &p); return 0;}early_param("cma", early_cma); struct cma *dev_get_cma_area(struct device *dev){ if (dev && dev->cma_area) return dev->cma_area; return dma_contiguous_default_area;}EXPORT_SYMBOL_GPL(dev_get_cma_area); #ifdef CONFIG_DMA_NUMA_CMA static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];static phys_addr_t numa_cma_size[MAX_NUMNODES] __initdata;static struct cma *dma_contiguous_pernuma_area[MAX_NUMNODES];static phys_addr_t pernuma_size_bytes __initdata; static int __init early_numa_cma(char *p){ int nid, count = 0; unsigned long tmp; char *s = p; while (*s) { if (sscanf(s, "%lu%n", &tmp, &count) != 1) break; if (s[count] == ':') { if (tmp >= MAX_NUMNODES) break; nid = array_index_nospec(tmp, MAX_NUMNODES); s += count + 1; tmp = memparse(s, &s); numa_cma_size[nid] = tmp; if (*s == ',') s++; else break; } else break; } return 0;}early_param("numa_cma", early_numa_cma); static int __init early_cma_pernuma(char *p){ pernuma_size_bytes = memparse(p, &p); return 0;}early_param("cma_pernuma", early_cma_pernuma);#endif #ifdef CONFIG_CMA_SIZE_PERCENTAGE static phys_addr_t __init __maybe_unused cma_early_percent_memory(void){ unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size()); return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;} #else static inline __maybe_unused phys_addr_t cma_early_percent_memory(void){ return 0;} #endif #ifdef CONFIG_DMA_NUMA_CMAstatic void __init dma_numa_cma_reserve(void){ int nid; for_each_node(nid) { int ret; char name[CMA_MAX_NAME]; struct cma **cma; if (!node_online(nid)) { if (pernuma_size_bytes || numa_cma_size[nid]) pr_warn("invalid node %d specified\n", nid); continue; } if (pernuma_size_bytes) { cma = &dma_contiguous_pernuma_area[nid]; snprintf(name, sizeof(name), "pernuma%d", nid); ret = cma_declare_contiguous_nid(0, pernuma_size_bytes, 0, 0, 0, false, name, cma, nid); if (ret) pr_warn("%s: reservation failed: err %d, node %d", __func__, ret, nid); } if (numa_cma_size[nid]) { cma = &dma_contiguous_numa_area[nid]; snprintf(name, sizeof(name), "numa%d", nid); ret = cma_declare_contiguous_nid(0, numa_cma_size[nid], 0, 0, 0, false, name, cma, nid); if (ret) pr_warn("%s: reservation failed: err %d, node %d", __func__, ret, nid); } }}#elsestatic inline void __init dma_numa_cma_reserve(void){}#endif /** * 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 * 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; phys_addr_t selected_base = 0; phys_addr_t selected_limit = limit; bool fixed = false; dma_numa_cma_reserve(); pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); if (size_cmdline != -1) { selected_size = size_cmdline; selected_base = base_cmdline; /* Hornor the user setup dma address limit */ selected_limit = limit_cmdline ?: limit; if (base_cmdline + size_cmdline == limit_cmdline) fixed = true; } 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 && !dma_contiguous_default_area) { int ret; pr_debug("%s: reserving %ld MiB for global area\n", __func__, (unsigned long)selected_size / SZ_1M); ret = dma_contiguous_reserve_area(selected_size, selected_base, selected_limit, &dma_contiguous_default_area, fixed); if (ret) return; /* * We need to insert the new area in our list to avoid * any inconsistencies between having the default area * listed in the DT or not. * * The DT case is handled by rmem_cma_setup() and will * always insert all its areas in our list. However, if * it didn't run (because OF_RESERVED_MEM isn't set, or * there's no DT region specified), then we don't have a * default area yet, and no area in our list. * * This block creates the default area in such a case, * but we also need to insert it in our list to avoid * having a default area but an empty list. */ ret = dma_contiguous_insert_area(dma_contiguous_default_area); if (ret) pr_warn("Couldn't queue default CMA region for heap creation."); }} void __weakdma_contiguous_early_fixup(phys_addr_t base, unsigned long size){} /** * 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. * @fixed: hint about where to place the reserved area * * 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. * * If @fixed is true, reserve contiguous area at exactly @base. If false, * reserve in range from @base to @limit. */int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, phys_addr_t limit, struct cma **res_cma, bool fixed){ int ret; ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed, "reserved", res_cma); if (ret) return ret; /* Architecture specific contiguous memory fixup. */ dma_contiguous_early_fixup(cma_get_base(*res_cma), cma_get_size(*res_cma)); return 0;} /** * dma_alloc_from_contiguous() - allocate pages from contiguous area * @dev: Pointer to device for which the allocation is performed. * @count: Requested number of pages. * @align: Requested alignment of pages (in PAGE_SIZE order). * @no_warn: Avoid printing message about failed allocation. * * This function allocates memory buffer for specified device. It uses * device specific contiguous memory area if available or the default * global one. Requires architecture specific dev_get_cma_area() helper * function. */struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, unsigned int align, bool no_warn){ if (align > CONFIG_CMA_ALIGNMENT) align = CONFIG_CMA_ALIGNMENT; return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);} /** * dma_release_from_contiguous() - release allocated pages * @dev: Pointer to device for which the pages were allocated. * @pages: Allocated pages. * @count: Number of allocated pages. * * This function releases memory allocated by dma_alloc_from_contiguous(). * It returns false when provided pages do not belong to contiguous area and * true otherwise. */bool dma_release_from_contiguous(struct device *dev, struct page *pages, int count){ return cma_release(dev_get_cma_area(dev), pages, count);} static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp){ unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT); return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN);} /** * dma_alloc_contiguous() - allocate contiguous pages * @dev: Pointer to device for which the allocation is performed. * @size: Requested allocation size. * @gfp: Allocation flags. * * tries to use device specific contiguous memory area if available, or it * tries to use per-numa cma, if the allocation fails, it will fallback to * try default global one. * * Note that it bypass one-page size of allocations from the per-numa and * global area as the addresses within one page are always contiguous, so * there is no need to waste CMA pages for that kind; it also helps reduce * fragmentations. */struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp){#ifdef CONFIG_DMA_NUMA_CMA int nid = dev_to_node(dev);#endif /* CMA can be used only in the context which permits sleeping */ if (!gfpflags_allow_blocking(gfp)) return NULL; if (dev->cma_area) return cma_alloc_aligned(dev->cma_area, size, gfp); if (size <= PAGE_SIZE) return NULL; #ifdef CONFIG_DMA_NUMA_CMA if (nid != NUMA_NO_NODE && !(gfp & (GFP_DMA | GFP_DMA32))) { struct cma *cma = dma_contiguous_pernuma_area[nid]; struct page *page; if (cma) { page = cma_alloc_aligned(cma, size, gfp); if (page) return page; } cma = dma_contiguous_numa_area[nid]; if (cma) { page = cma_alloc_aligned(cma, size, gfp); if (page) return page; } }#endif if (!dma_contiguous_default_area) return NULL; return cma_alloc_aligned(dma_contiguous_default_area, size, gfp);} /** * dma_free_contiguous() - release allocated pages * @dev: Pointer to device for which the pages were allocated. * @page: Pointer to the allocated pages. * @size: Size of allocated pages. * * This function releases memory allocated by dma_alloc_contiguous(). As the * cma_release returns false when provided pages do not belong to contiguous * area and true otherwise, this function then does a fallback __free_pages() * upon a false-return. */void dma_free_contiguous(struct device *dev, struct page *page, size_t size){ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; /* if dev has its own cma, free page from there */ if (dev->cma_area) { if (cma_release(dev->cma_area, page, count)) return; } else { /* * otherwise, page is from either per-numa cma or default cma */#ifdef CONFIG_DMA_NUMA_CMA if (cma_release(dma_contiguous_pernuma_area[page_to_nid(page)], page, count)) return; if (cma_release(dma_contiguous_numa_area[page_to_nid(page)], page, count)) return;#endif if (cma_release(dma_contiguous_default_area, page, count)) return; } /* not in any cma, free from buddy */ __free_pages(page, get_order(size));} /* * Support for reserved memory regions defined in device tree */#ifdef CONFIG_OF_RESERVED_MEM#include <linux/of.h>#include <linux/of_fdt.h>#include <linux/of_reserved_mem.h>Lines 1–500 of 602. 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// SPDX-License-Identifier: GPL-2.0+ /* * Contiguous Memory Allocator for DMA mapping framework * Copyright (c) 2010-2011 by Samsung Electronics. * Written by: * Marek Szyprowski <m.szyprowski@samsung.com> * Michal Nazarewicz <mina86@mina86.com> * * Contiguous Memory Allocator * * The Contiguous Memory Allocator (CMA) makes it possible to * allocate big contiguous chunks of memory after the system has * booted. * * Why is it needed? * * Various devices on embedded systems have no scatter-getter and/or * IO map support and require contiguous blocks of memory to * operate. They include devices such as cameras, hardware video * coders, etc. * * Such devices often require big memory buffers (a full HD frame * is, for instance, more than 2 mega pixels large, i.e. more than 6 * MB of memory), which makes mechanisms such as kmalloc() or * alloc_page() ineffective. * * At the same time, a solution where a big memory region is * reserved for a device is suboptimal since often more memory is * reserved then strictly required and, moreover, the memory is * inaccessible to page system even if device drivers don't use it. * * CMA tries to solve this issue by operating on memory regions * where only movable pages can be allocated from. This way, kernel * can use the memory for pagecache and when device driver requests * it, allocated pages can be migrated. */ #define pr_fmt(fmt) "cma: " fmt #include <asm/page.h> #include <linux/memblock.h> #include <linux/err.h> #include <linux/sizes.h> #include <linux/dma-map-ops.h> #include <linux/cma.h> #include <linux/nospec.h> #ifdef CONFIG_CMA_SIZE_MBYTES #define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES #else #define CMA_SIZE_MBYTES 0 #endif static struct cma *dma_contiguous_areas[MAX_CMA_AREAS]; static unsigned int dma_contiguous_areas_num; static int dma_contiguous_insert_area(struct cma *cma) { if (dma_contiguous_areas_num >= ARRAY_SIZE(dma_contiguous_areas)) return -EINVAL; dma_contiguous_areas[dma_contiguous_areas_num++] = cma; return 0; } /** * dma_contiguous_get_area_by_idx() - Get contiguous area at given index * @idx: index of the area we query * * Queries for the contiguous area located at index @idx. * * Returns: * A pointer to the requested contiguous area, or NULL otherwise. */ struct cma *dma_contiguous_get_area_by_idx(unsigned int idx) { if (idx >= dma_contiguous_areas_num) return NULL; return dma_contiguous_areas[idx]; } EXPORT_SYMBOL_GPL(dma_contiguous_get_area_by_idx); static struct cma *dma_contiguous_default_area; /* * Default global CMA area size can be defined in kernel's .config. * This is useful mainly for distro maintainers to create a kernel * that works correctly for most supported systems. * The size can be set in bytes or as a percentage of the total memory * in the system. * * Users, who want to set the size of global CMA area for their system * should use cma= kernel parameter. */ #define size_bytes ((phys_addr_t)CMA_SIZE_MBYTES * SZ_1M) static phys_addr_t size_cmdline __initdata = -1; static phys_addr_t base_cmdline __initdata; static phys_addr_t limit_cmdline __initdata; static int __init early_cma(char *p) { if (!p) { pr_err("Config string not provided\n"); return -EINVAL; } size_cmdline = memparse(p, &p); if (*p != '@') return 0; base_cmdline = memparse(p + 1, &p); if (*p != '-') { limit_cmdline = base_cmdline + size_cmdline; return 0; } limit_cmdline = memparse(p + 1, &p); return 0; } early_param("cma", early_cma); struct cma *dev_get_cma_area(struct device *dev) { if (dev && dev->cma_area) return dev->cma_area; return dma_contiguous_default_area; } EXPORT_SYMBOL_GPL(dev_get_cma_area); #ifdef CONFIG_DMA_NUMA_CMA static struct cma *dma_contiguous_numa_area[MAX_NUMNODES]; static phys_addr_t numa_cma_size[MAX_NUMNODES] __initdata; static struct cma *dma_contiguous_pernuma_area[MAX_NUMNODES]; static phys_addr_t pernuma_size_bytes __initdata; static int __init early_numa_cma(char *p) { int nid, count = 0; unsigned long tmp; char *s = p; while (*s) { if (sscanf(s, "%lu%n", &tmp, &count) != 1) break; if (s[count] == ':') { if (tmp >= MAX_NUMNODES) break; nid = array_index_nospec(tmp, MAX_NUMNODES); s += count + 1; tmp = memparse(s, &s); numa_cma_size[nid] = tmp; if (*s == ',') s++; else break; } else break; } return 0; } early_param("numa_cma", early_numa_cma); static int __init early_cma_pernuma(char *p) { pernuma_size_bytes = memparse(p, &p); return 0; } early_param("cma_pernuma", early_cma_pernuma); #endif #ifdef CONFIG_CMA_SIZE_PERCENTAGE static phys_addr_t __init __maybe_unused cma_early_percent_memory(void) { unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size()); return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; } #else static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) { return 0; } #endif #ifdef CONFIG_DMA_NUMA_CMA static void __init dma_numa_cma_reserve(void) { int nid; for_each_node(nid) { int ret; char name[CMA_MAX_NAME]; struct cma **cma; if (!node_online(nid)) { if (pernuma_size_bytes || numa_cma_size[nid]) pr_warn("invalid node %d specified\n", nid); continue; } if (pernuma_size_bytes) { cma = &dma_contiguous_pernuma_area[nid]; snprintf(name, sizeof(name), "pernuma%d", nid); ret = cma_declare_contiguous_nid(0, pernuma_size_bytes, 0, 0, 0, false, name, cma, nid); if (ret) pr_warn("%s: reservation failed: err %d, node %d", __func__, ret, nid); } if (numa_cma_size[nid]) { cma = &dma_contiguous_numa_area[nid]; snprintf(name, sizeof(name), "numa%d", nid); ret = cma_declare_contiguous_nid(0, numa_cma_size[nid], 0, 0, 0, false, name, cma, nid); if (ret) pr_warn("%s: reservation failed: err %d, node %d", __func__, ret, nid); } } } #else static inline void __init dma_numa_cma_reserve(void) { } #endif /** * 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 * 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; phys_addr_t selected_base = 0; phys_addr_t selected_limit = limit; bool fixed = false; dma_numa_cma_reserve(); pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); if (size_cmdline != -1) { selected_size = size_cmdline; selected_base = base_cmdline; /* Hornor the user setup dma address limit */ selected_limit = limit_cmdline ?: limit; if (base_cmdline + size_cmdline == limit_cmdline) fixed = true; } 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 && !dma_contiguous_default_area) { int ret; pr_debug("%s: reserving %ld MiB for global area\n", __func__, (unsigned long)selected_size / SZ_1M); ret = dma_contiguous_reserve_area(selected_size, selected_base, selected_limit, &dma_contiguous_default_area, fixed); if (ret) return; /* * We need to insert the new area in our list to avoid * any inconsistencies between having the default area * listed in the DT or not. * * The DT case is handled by rmem_cma_setup() and will * always insert all its areas in our list. However, if * it didn't run (because OF_RESERVED_MEM isn't set, or * there's no DT region specified), then we don't have a * default area yet, and no area in our list. * * This block creates the default area in such a case, * but we also need to insert it in our list to avoid * having a default area but an empty list. */ ret = dma_contiguous_insert_area(dma_contiguous_default_area); if (ret) pr_warn("Couldn't queue default CMA region for heap creation."); } } void __weak dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { } /** * 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. * @fixed: hint about where to place the reserved area * * 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. * * If @fixed is true, reserve contiguous area at exactly @base. If false, * reserve in range from @base to @limit. */ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, phys_addr_t limit, struct cma **res_cma, bool fixed) { int ret; ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed, "reserved", res_cma); if (ret) return ret; /* Architecture specific contiguous memory fixup. */ dma_contiguous_early_fixup(cma_get_base(*res_cma), cma_get_size(*res_cma)); return 0; } /** * dma_alloc_from_contiguous() - allocate pages from contiguous area * @dev: Pointer to device for which the allocation is performed. * @count: Requested number of pages. * @align: Requested alignment of pages (in PAGE_SIZE order). * @no_warn: Avoid printing message about failed allocation. * * This function allocates memory buffer for specified device. It uses * device specific contiguous memory area if available or the default * global one. Requires architecture specific dev_get_cma_area() helper * function. */ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, unsigned int align, bool no_warn) { if (align > CONFIG_CMA_ALIGNMENT) align = CONFIG_CMA_ALIGNMENT; return cma_alloc(dev_get_cma_area(dev), count, align, no_warn); } /** * dma_release_from_contiguous() - release allocated pages * @dev: Pointer to device for which the pages were allocated. * @pages: Allocated pages. * @count: Number of allocated pages. * * This function releases memory allocated by dma_alloc_from_contiguous(). * It returns false when provided pages do not belong to contiguous area and * true otherwise. */ bool dma_release_from_contiguous(struct device *dev, struct page *pages, int count) { return cma_release(dev_get_cma_area(dev), pages, count); } static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp) { unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT); return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN); } /** * dma_alloc_contiguous() - allocate contiguous pages * @dev: Pointer to device for which the allocation is performed. * @size: Requested allocation size. * @gfp: Allocation flags. * * tries to use device specific contiguous memory area if available, or it * tries to use per-numa cma, if the allocation fails, it will fallback to * try default global one. * * Note that it bypass one-page size of allocations from the per-numa and * global area as the addresses within one page are always contiguous, so * there is no need to waste CMA pages for that kind; it also helps reduce * fragmentations. */ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) { #ifdef CONFIG_DMA_NUMA_CMA int nid = dev_to_node(dev); #endif /* CMA can be used only in the context which permits sleeping */ if (!gfpflags_allow_blocking(gfp)) return NULL; if (dev->cma_area) return cma_alloc_aligned(dev->cma_area, size, gfp); if (size <= PAGE_SIZE) return NULL; #ifdef CONFIG_DMA_NUMA_CMA if (nid != NUMA_NO_NODE && !(gfp & (GFP_DMA | GFP_DMA32))) { struct cma *cma = dma_contiguous_pernuma_area[nid]; struct page *page; if (cma) { page = cma_alloc_aligned(cma, size, gfp); if (page) return page; } cma = dma_contiguous_numa_area[nid]; if (cma) { page = cma_alloc_aligned(cma, size, gfp); if (page) return page; } } #endif if (!dma_contiguous_default_area) return NULL; return cma_alloc_aligned(dma_contiguous_default_area, size, gfp); } /** * dma_free_contiguous() - release allocated pages * @dev: Pointer to device for which the pages were allocated. * @page: Pointer to the allocated pages. * @size: Size of allocated pages. * * This function releases memory allocated by dma_alloc_contiguous(). As the * cma_release returns false when provided pages do not belong to contiguous * area and true otherwise, this function then does a fallback __free_pages() * upon a false-return. */ void dma_free_contiguous(struct device *dev, struct page *page, size_t size) { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; /* if dev has its own cma, free page from there */ if (dev->cma_area) { if (cma_release(dev->cma_area, page, count)) return; } else { /* * otherwise, page is from either per-numa cma or default cma */ #ifdef CONFIG_DMA_NUMA_CMA if (cma_release(dma_contiguous_pernuma_area[page_to_nid(page)], page, count)) return; if (cma_release(dma_contiguous_numa_area[page_to_nid(page)], page, count)) return; #endif if (cma_release(dma_contiguous_default_area, page, count)) return; } /* not in any cma, free from buddy */ __free_pages(page, get_order(size)); } /* * Support for reserved memory regions defined in device tree */ #ifdef CONFIG_OF_RESERVED_MEM #include <linux/of.h> #include <linux/of_fdt.h> #include <linux/of_reserved_mem.h>