diff options
Diffstat (limited to 'kernel/dma/contiguous.c')
| -rw-r--r-- | kernel/dma/contiguous.c | 249 |
1 files changed, 202 insertions, 47 deletions
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 15bc5026c485..055da410ac71 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -5,24 +5,46 @@ * 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 -#ifdef CONFIG_CMA_DEBUG -#ifndef DEBUG -# define DEBUG -#endif -#endif - #include <asm/page.h> -#include <asm/dma-contiguous.h> #include <linux/memblock.h> #include <linux/err.h> #include <linux/sizes.h> -#include <linux/dma-contiguous.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 @@ -69,20 +91,57 @@ static int __init early_cma(char *p) } early_param("cma", early_cma); +#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) { - struct memblock_region *reg; - unsigned long total_pages = 0; - - /* - * We cannot use memblock_phys_mem_size() here, because - * memblock_analyze() has not been called yet. - */ - for_each_memblock(memory, reg) - total_pages += memblock_region_memory_end_pfn(reg) - - memblock_region_memory_base_pfn(reg); + unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size()); return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; } @@ -96,6 +155,51 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) #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). @@ -112,6 +216,8 @@ void __init dma_contiguous_reserve(phys_addr_t limit) 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) { @@ -143,6 +249,11 @@ void __init dma_contiguous_reserve(phys_addr_t limit) } } +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), @@ -215,40 +326,65 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, 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. * - * This function allocates contiguous memory buffer for specified device. It - * tries to use device specific contiguous memory area if available, or the - * default global one. + * 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 byapss one-page size of allocations from the 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. + * 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) { - size_t count = size >> PAGE_SHIFT; - struct page *page = NULL; - struct cma *cma = NULL; - - if (dev && dev->cma_area) - cma = dev->cma_area; - else if (count > 1) - cma = dma_contiguous_default_area; +#ifdef CONFIG_DMA_NUMA_CMA + int nid = dev_to_node(dev); +#endif /* CMA can be used only in the context which permits sleeping */ - if (cma && gfpflags_allow_blocking(gfp)) { - size_t align = get_order(size); - size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT); - - page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN); + 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 page; + return cma_alloc_aligned(dma_contiguous_default_area, size, gfp); } /** @@ -264,9 +400,30 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) */ void dma_free_contiguous(struct device *dev, struct page *page, size_t size) { - if (!cma_release(dev_get_cma_area(dev), page, - PAGE_ALIGN(size) >> PAGE_SHIFT)) - __free_pages(page, get_order(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)); } /* @@ -282,14 +439,14 @@ void dma_free_contiguous(struct device *dev, struct page *page, size_t size) static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev) { - dev_set_cma_area(dev, rmem->priv); + dev->cma_area = rmem->priv; return 0; } static void rmem_cma_device_release(struct reserved_mem *rmem, struct device *dev) { - dev_set_cma_area(dev, NULL); + dev->cma_area = NULL; } static const struct reserved_mem_ops rmem_cma_ops = { @@ -299,8 +456,6 @@ static const struct reserved_mem_ops rmem_cma_ops = { static int __init rmem_cma_setup(struct reserved_mem *rmem) { - phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); - phys_addr_t mask = align - 1; unsigned long node = rmem->fdt_node; bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL); struct cma *cma; @@ -316,7 +471,7 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) of_get_flat_dt_prop(node, "no-map", NULL)) return -EINVAL; - if ((rmem->base & mask) || (rmem->size & mask)) { + if (!IS_ALIGNED(rmem->base | rmem->size, CMA_MIN_ALIGNMENT_BYTES)) { pr_err("Reserved memory: incorrect alignment of CMA region\n"); return -EINVAL; } @@ -330,7 +485,7 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) dma_contiguous_early_fixup(rmem->base, rmem->size); if (default_cma) - dma_contiguous_set_default(cma); + dma_contiguous_default_area = cma; rmem->ops = &rmem_cma_ops; rmem->priv = cma; |