From d4932f9e81ae7a7bf3c3967e48373909b9c98ee5 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Thu, 9 Oct 2014 15:26:44 -0700 Subject: [PATCH] arm64: add atomic pool for non-coherent and CMA allocations Neither CMA nor noncoherent allocations support atomic allocations. Add a dedicated atomic pool to support this. Reviewed-by: Catalin Marinas Signed-off-by: Laura Abbott Cc: Arnd Bergmann Cc: David Riley Cc: Olof Johansson Cc: Ritesh Harjain Cc: Russell King Cc: Thierry Reding Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm64/Kconfig | 1 + arch/arm64/mm/dma-mapping.c | 164 +++++++++++++++++++++++++++++++----- 2 files changed, 146 insertions(+), 19 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9746dc24a117..e96cbe84d5ae 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -18,6 +18,7 @@ config ARM64 select COMMON_CLK select CPU_PM if (SUSPEND || CPU_IDLE) select DCACHE_WORD_ACCESS + select GENERIC_ALLOCATOR select GENERIC_CLOCKEVENTS select GENERIC_CLOCKEVENTS_BROADCAST if SMP select GENERIC_CPU_AUTOPROBE diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 2c71077cacfd..d92094203913 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -38,6 +39,54 @@ static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot, return prot; } +static struct gen_pool *atomic_pool; + +#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K +static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE; + +static int __init early_coherent_pool(char *p) +{ + atomic_pool_size = memparse(p, &p); + return 0; +} +early_param("coherent_pool", early_coherent_pool); + +static void *__alloc_from_pool(size_t size, struct page **ret_page) +{ + unsigned long val; + void *ptr = NULL; + + if (!atomic_pool) { + WARN(1, "coherent pool not initialised!\n"); + return NULL; + } + + val = gen_pool_alloc(atomic_pool, size); + if (val) { + phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val); + + *ret_page = phys_to_page(phys); + ptr = (void *)val; + } + + return ptr; +} + +static bool __in_atomic_pool(void *start, size_t size) +{ + return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); +} + +static int __free_from_pool(void *start, size_t size) +{ + if (!__in_atomic_pool(start, size)) + return 0; + + gen_pool_free(atomic_pool, (unsigned long)start, size); + + return 1; +} + static void *__dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) @@ -50,7 +99,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, if (IS_ENABLED(CONFIG_ZONE_DMA) && dev->coherent_dma_mask <= DMA_BIT_MASK(32)) flags |= GFP_DMA; - if (IS_ENABLED(CONFIG_DMA_CMA)) { + if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) { struct page *page; size = PAGE_ALIGN(size); @@ -70,50 +119,54 @@ static void __dma_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs) { + bool freed; + phys_addr_t paddr = dma_to_phys(dev, dma_handle); + if (dev == NULL) { WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); return; } - if (IS_ENABLED(CONFIG_DMA_CMA)) { - phys_addr_t paddr = dma_to_phys(dev, dma_handle); - - dma_release_from_contiguous(dev, + freed = dma_release_from_contiguous(dev, phys_to_page(paddr), size >> PAGE_SHIFT); - } else { + if (!freed) swiotlb_free_coherent(dev, size, vaddr, dma_handle); - } } static void *__dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) { - struct page *page, **map; + struct page *page; void *ptr, *coherent_ptr; - int order, i; size = PAGE_ALIGN(size); - order = get_order(size); + + if (!(flags & __GFP_WAIT)) { + struct page *page = NULL; + void *addr = __alloc_from_pool(size, &page); + + if (addr) + *dma_handle = phys_to_dma(dev, page_to_phys(page)); + + return addr; + + } ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs); if (!ptr) goto no_mem; - map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA); - if (!map) - goto no_map; /* remove any dirty cache lines on the kernel alias */ __dma_flush_range(ptr, ptr + size); /* create a coherent mapping */ page = virt_to_page(ptr); - for (i = 0; i < (size >> PAGE_SHIFT); i++) - map[i] = page + i; - coherent_ptr = vmap(map, size >> PAGE_SHIFT, VM_MAP, - __get_dma_pgprot(attrs, __pgprot(PROT_NORMAL_NC), false)); - kfree(map); + coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP, + __get_dma_pgprot(attrs, + __pgprot(PROT_NORMAL_NC), false), + NULL); if (!coherent_ptr) goto no_map; @@ -132,6 +185,8 @@ static void __dma_free_noncoherent(struct device *dev, size_t size, { void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); + if (__free_from_pool(vaddr, size)) + return; vunmap(vaddr); __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); } @@ -307,6 +362,67 @@ EXPORT_SYMBOL(coherent_swiotlb_dma_ops); extern int swiotlb_late_init_with_default_size(size_t default_size); +static int __init atomic_pool_init(void) +{ + pgprot_t prot = __pgprot(PROT_NORMAL_NC); + unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; + struct page *page; + void *addr; + unsigned int pool_size_order = get_order(atomic_pool_size); + + if (dev_get_cma_area(NULL)) + page = dma_alloc_from_contiguous(NULL, nr_pages, + pool_size_order); + else + page = alloc_pages(GFP_DMA, pool_size_order); + + if (page) { + int ret; + void *page_addr = page_address(page); + + memset(page_addr, 0, atomic_pool_size); + __dma_flush_range(page_addr, page_addr + atomic_pool_size); + + atomic_pool = gen_pool_create(PAGE_SHIFT, -1); + if (!atomic_pool) + goto free_page; + + addr = dma_common_contiguous_remap(page, atomic_pool_size, + VM_USERMAP, prot, atomic_pool_init); + + if (!addr) + goto destroy_genpool; + + ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr, + page_to_phys(page), + atomic_pool_size, -1); + if (ret) + goto remove_mapping; + + gen_pool_set_algo(atomic_pool, + gen_pool_first_fit_order_align, + (void *)PAGE_SHIFT); + + pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n", + atomic_pool_size / 1024); + return 0; + } + goto out; + +remove_mapping: + dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP); +destroy_genpool: + gen_pool_destroy(atomic_pool); + atomic_pool = NULL; +free_page: + if (!dma_release_from_contiguous(NULL, page, nr_pages)) + __free_pages(page, pool_size_order); +out: + pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n", + atomic_pool_size / 1024); + return -ENOMEM; +} + static int __init swiotlb_late_init(void) { size_t swiotlb_size = min(SZ_64M, MAX_ORDER_NR_PAGES << PAGE_SHIFT); @@ -315,7 +431,17 @@ static int __init swiotlb_late_init(void) return swiotlb_late_init_with_default_size(swiotlb_size); } -arch_initcall(swiotlb_late_init); + +static int __init arm64_dma_init(void) +{ + int ret = 0; + + ret |= swiotlb_late_init(); + ret |= atomic_pool_init(); + + return ret; +} +arch_initcall(arm64_dma_init); #define PREALLOC_DMA_DEBUG_ENTRIES 4096 -- 2.20.1