From: Christoph Hellwig Date: Fri, 14 Aug 2020 12:26:24 +0200 Subject: dma-pool: fix coherent pool allocations for IOMMU mappings Git-commit: 9420139f516d7fbc248ce17f35275cb005ed98ea Patch-mainline: v5.9-rc2 References: bsc#1175898, ECO-2743 When allocating coherent pool memory for an IOMMU mapping we don't care about the DMA mask. Move the guess for the initial GFP mask into the dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer argument so that it doesn't get applied to the IOMMU case. Signed-off-by: Christoph Hellwig Tested-by: Amit Pundir Acked-by: Joerg Roedel --- drivers/iommu/dma-iommu.c | 4 - include/linux/dma-direct.h | 3 - include/linux/dma-mapping.h | 5 + kernel/dma/direct.c | 13 +++- kernel/dma/pool.c | 116 ++++++++++++++++++-------------------------- 5 files changed, 63 insertions(+), 78 deletions(-) --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1014,8 +1014,8 @@ static void *iommu_dma_alloc(struct devi if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !gfpflags_allow_blocking(gfp) && !coherent) - cpu_addr = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &page, - gfp); + page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr, + gfp, NULL); else cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs); if (!cpu_addr) --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -67,9 +67,6 @@ static inline bool dma_capable(struct de } u64 dma_direct_get_required_mask(struct device *dev); -gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, - u64 *phys_mask); -bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size); void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs); void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -637,8 +637,9 @@ void *dma_common_pages_remap(struct page pgprot_t prot, const void *caller); void dma_common_free_remap(void *cpu_addr, size_t size); -void *dma_alloc_from_pool(struct device *dev, size_t size, - struct page **ret_page, gfp_t flags); +struct page *dma_alloc_from_pool(struct device *dev, size_t size, + void **cpu_addr, gfp_t flags, + bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)); bool dma_free_from_pool(struct device *dev, void *start, size_t size); int --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -57,7 +57,7 @@ u64 dma_direct_get_required_mask(struct return (1ULL << (fls64(max_dma) - 1)) * 2 - 1; } -gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, +static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, u64 *phys_limit) { u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit); @@ -82,7 +82,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct return 0; } -bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) +static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) { return phys_to_dma_direct(dev, phys) + size - 1 <= min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit); @@ -175,8 +175,13 @@ void *dma_direct_alloc_pages(struct devi size = PAGE_ALIGN(size); if (dma_should_alloc_from_pool(dev, gfp, attrs)) { - ret = dma_alloc_from_pool(dev, size, &page, gfp); - if (!ret) + u64 phys_mask; + + gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, + &phys_mask); + page = dma_alloc_from_pool(dev, size, &ret, gfp, + dma_coherent_ok); + if (!page) return NULL; goto done; } --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -196,93 +196,75 @@ static int __init dma_atomic_pool_init(v } postcore_initcall(dma_atomic_pool_init); -static inline struct gen_pool *dma_guess_pool_from_device(struct device *dev) +static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp) { - u64 phys_mask; - gfp_t gfp; - - gfp = dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, - &phys_mask); - if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp == GFP_DMA) + if (prev == NULL) { + if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) + return atomic_pool_dma32; + if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) + return atomic_pool_dma; + return atomic_pool_kernel; + } + if (prev == atomic_pool_kernel) + return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma; + if (prev == atomic_pool_dma32) return atomic_pool_dma; - if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32) - return atomic_pool_dma32; - return atomic_pool_kernel; + return NULL; } -static inline struct gen_pool *dma_get_safer_pool(struct gen_pool *bad_pool) +static struct page *__dma_alloc_from_pool(struct device *dev, size_t size, + struct gen_pool *pool, void **cpu_addr, + bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)) { - if (bad_pool == atomic_pool_kernel) - return atomic_pool_dma32 ? : atomic_pool_dma; - - if (bad_pool == atomic_pool_dma32) - return atomic_pool_dma; + unsigned long addr; + phys_addr_t phys; - return NULL; -} + addr = gen_pool_alloc(pool, size); + if (!addr) + return NULL; + + phys = gen_pool_virt_to_phys(pool, addr); + if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) { + gen_pool_free(pool, addr, size); + return NULL; + } -static inline struct gen_pool *dma_guess_pool(struct device *dev, - struct gen_pool *bad_pool) -{ - if (bad_pool) - return dma_get_safer_pool(bad_pool); + if (gen_pool_avail(pool) < atomic_pool_size) + schedule_work(&atomic_pool_work); - return dma_guess_pool_from_device(dev); + *cpu_addr = (void *)addr; + memset(*cpu_addr, 0, size); + return pfn_to_page(__phys_to_pfn(phys)); } -void *dma_alloc_from_pool(struct device *dev, size_t size, - struct page **ret_page, gfp_t flags) +struct page *dma_alloc_from_pool(struct device *dev, size_t size, + void **cpu_addr, gfp_t gfp, + bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)) { struct gen_pool *pool = NULL; - unsigned long val = 0; - void *ptr = NULL; - phys_addr_t phys; + struct page *page; - while (1) { - pool = dma_guess_pool(dev, pool); - if (!pool) { - WARN(1, "Failed to get suitable pool for %s\n", - dev_name(dev)); - break; - } - - val = gen_pool_alloc(pool, size); - if (!val) - continue; - - phys = gen_pool_virt_to_phys(pool, val); - if (dma_coherent_ok(dev, phys, size)) - break; - - gen_pool_free(pool, val, size); - val = 0; + while ((pool = dma_guess_pool(pool, gfp))) { + page = __dma_alloc_from_pool(dev, size, pool, cpu_addr, + phys_addr_ok); + if (page) + return page; } - - if (val) { - *ret_page = pfn_to_page(__phys_to_pfn(phys)); - ptr = (void *)val; - memset(ptr, 0, size); - - if (gen_pool_avail(pool) < atomic_pool_size) - schedule_work(&atomic_pool_work); - } - - return ptr; + WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev)); + return NULL; } bool dma_free_from_pool(struct device *dev, void *start, size_t size) { struct gen_pool *pool = NULL; - while (1) { - pool = dma_guess_pool(dev, pool); - if (!pool) - return false; - - if (addr_in_gen_pool(pool, (unsigned long)start, size)) { - gen_pool_free(pool, (unsigned long)start, size); - return true; - } + while ((pool = dma_guess_pool(pool, 0))) { + if (!addr_in_gen_pool(pool, (unsigned long)start, size)) + continue; + gen_pool_free(pool, (unsigned long)start, size); + return true; } + + return false; }