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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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 phys_addr_t pernuma_size_bytes __initdata;static bool numa_cma_configured __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; }
numa_cma_configured = true; return 0;}early_param("numa_cma", early_numa_cma);
static int __init early_cma_pernuma(char *p){ pernuma_size_bytes = memparse(p, &p); numa_cma_configured = true; 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;
if (IS_ENABLED(CONFIG_CMA_SIZE_PERNUMA) && !numa_cma_configured && dma_contiguous_default_area && nr_online_nodes > 1) pernuma_size_bytes = cma_get_size(dma_contiguous_default_area);
for_each_node(nid) { int size, 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; }
/* per-node numa setting has the priority */ size = numa_cma_size[nid] ?: pernuma_size_bytes; if (!size) continue;
cma = &dma_contiguous_numa_area[nid]; snprintf(name, sizeof(name), "numa%d", nid); ret = cma_declare_contiguous_nid(0, size, 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;
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."); }
dma_numa_cma_reserve();}
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_numa_area[nid]; struct page *page; 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_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>
#undef pr_fmt#define pr_fmt(fmt) fmt
static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev){ dev->cma_area = rmem->priv; return 0;}
static void rmem_cma_device_release(struct reserved_mem *rmem, struct device *dev){ dev->cma_area = NULL;}
static int __init __rmem_cma_verify_node(unsigned long node){ if (!of_get_flat_dt_prop(node, "reusable", NULL) || of_get_flat_dt_prop(node, "no-map", NULL)) return -ENODEV;
if (size_cmdline != -1 && of_get_flat_dt_prop(node, "linux,cma-default", NULL)) { pr_err("Skipping dt linux,cma-default node in favor for \"cma=\" kernel param.\n"); return -EBUSY; } return 0;}
static int __init rmem_cma_validate(unsigned long node, phys_addr_t *align){ int ret = __rmem_cma_verify_node(node);
if (ret) return ret;
if (align) *align = max_t(phys_addr_t, *align, CMA_MIN_ALIGNMENT_BYTES);
return 0;}
static int __init rmem_cma_fixup(unsigned long node, phys_addr_t base, phys_addr_t size){ int ret = __rmem_cma_verify_node(node);
if (ret) return ret;
/* Architecture specific contiguous memory fixup. */ dma_contiguous_early_fixup(base, size); return 0;}
static int __init rmem_cma_setup(unsigned long node, struct reserved_mem *rmem){ bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL); struct cma *cma; int ret;
ret = __rmem_cma_verify_node(node); if (ret) return ret;
if (!IS_ALIGNED(rmem->base | rmem->size, CMA_MIN_ALIGNMENT_BYTES)) { pr_err("Reserved memory: incorrect alignment of CMA region\n"); return -EINVAL; }
ret = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma); if (ret) { pr_err("Reserved memory: unable to setup CMA region\n"); return ret; }
if (default_cma) dma_contiguous_default_area = cma;
rmem->priv = cma;
pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M);
ret = dma_contiguous_insert_area(cma); if (ret) pr_warn("Couldn't store CMA reserved area.");
return 0;}
static const struct reserved_mem_ops rmem_cma_ops = { .node_validate = rmem_cma_validate, .node_fixup = rmem_cma_fixup, .node_init = rmem_cma_setup, .device_init = rmem_cma_device_init, .device_release = rmem_cma_device_release,};
RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", &rmem_cma_ops);#endif