ARM currently uses a bitmap for tracking atomic allocations. genalloc already handles this type of memory pool allocation so switch to using that instead. Signed-off-by: Laura Abbott <lauraa@xxxxxxxxxxxxxx> --- arch/arm/Kconfig | 1 + arch/arm/mm/dma-mapping.c | 143 ++++++++++++++-------------------------------- 2 files changed, 44 insertions(+), 100 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 245058b..190d085 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -13,6 +13,7 @@ config ARM select CLONE_BACKWARDS select CPU_PM if (SUSPEND || CPU_IDLE) select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS + select GENERIC_ALLOCATOR select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) select GENERIC_CLOCKEVENTS_BROADCAST if SMP select GENERIC_IDLE_POLL_SETUP diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f5190ac..02a1939 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -26,6 +26,7 @@ #include <linux/io.h> #include <linux/vmalloc.h> #include <linux/sizes.h> +#include <linux/genalloc.h> #include <asm/memory.h> #include <asm/highmem.h> @@ -313,40 +314,31 @@ static void __dma_free_remap(void *cpu_addr, size_t size) } #define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K +static struct gen_pool *atomic_pool; -struct dma_pool { - size_t size; - spinlock_t lock; - unsigned long *bitmap; - unsigned long nr_pages; - void *vaddr; - struct page **pages; -}; - -static struct dma_pool atomic_pool = { - .size = DEFAULT_DMA_COHERENT_POOL_SIZE, -}; +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); + atomic_pool_size = memparse(p, &p); return 0; } early_param("coherent_pool", early_coherent_pool); + void __init init_dma_coherent_pool_size(unsigned long size) { /* * Catch any attempt to set the pool size too late. */ - BUG_ON(atomic_pool.vaddr); + BUG_ON(atomic_pool); /* * Set architecture specific coherent pool size only if * it has not been changed by kernel command line parameter. */ - if (atomic_pool.size == DEFAULT_DMA_COHERENT_POOL_SIZE) - atomic_pool.size = size; + if (atomic_pool_size == DEFAULT_DMA_COHERENT_POOL_SIZE) + atomic_pool_size = size; } /* @@ -354,52 +346,43 @@ void __init init_dma_coherent_pool_size(unsigned long size) */ static int __init atomic_pool_init(void) { - struct dma_pool *pool = &atomic_pool; pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL); gfp_t gfp = GFP_KERNEL | GFP_DMA; - unsigned long nr_pages = pool->size >> PAGE_SHIFT; - unsigned long *bitmap; struct page *page; - struct page **pages; void *ptr; - int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long); - bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!bitmap) - goto no_bitmap; - - pages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL); - if (!pages) - goto no_pages; + atomic_pool = gen_pool_create(PAGE_SHIFT, -1); + if (!atomic_pool) + goto out; if (dev_get_cma_area(NULL)) - ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page, - atomic_pool_init); + ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot, + &page, atomic_pool_init); else - ptr = __alloc_remap_buffer(NULL, pool->size, gfp, prot, &page, - atomic_pool_init); + ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot, + &page, atomic_pool_init); if (ptr) { - int i; - - for (i = 0; i < nr_pages; i++) - pages[i] = page + i; - - spin_lock_init(&pool->lock); - pool->vaddr = ptr; - pool->pages = pages; - pool->bitmap = bitmap; - pool->nr_pages = nr_pages; - pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n", - (unsigned)pool->size / 1024); + int ret; + + ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr, + page_to_phys(page), + atomic_pool_size, -1); + if (ret) + goto destroy_genpool; + + gen_pool_set_algo(atomic_pool, + gen_pool_first_fit_order_align, NULL); + pr_info("DMA: preallocated %zd KiB pool for atomic coherent allocations\n", + atomic_pool_size / 1024); return 0; } - kfree(pages); -no_pages: - kfree(bitmap); -no_bitmap: - pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n", - (unsigned)pool->size / 1024); +destroy_genpool: + gen_pool_destroy(atomic_pool); + atomic_pool = NULL; +out: + pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n", + atomic_pool_size / 1024); return -ENOMEM; } /* @@ -494,76 +477,36 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, static void *__alloc_from_pool(size_t size, struct page **ret_page) { - struct dma_pool *pool = &atomic_pool; - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; - unsigned int pageno; - unsigned long flags; + unsigned long val; void *ptr = NULL; - unsigned long align_mask; - if (!pool->vaddr) { + if (!atomic_pool) { WARN(1, "coherent pool not initialised!\n"); return NULL; } - /* - * Align the region allocation - allocations from pool are rather - * small, so align them to their order in pages, minimum is a page - * size. This helps reduce fragmentation of the DMA space. - */ - align_mask = (1 << get_order(size)) - 1; - - spin_lock_irqsave(&pool->lock, flags); - pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages, - 0, count, align_mask); - if (pageno < pool->nr_pages) { - bitmap_set(pool->bitmap, pageno, count); - ptr = pool->vaddr + PAGE_SIZE * pageno; - *ret_page = pool->pages[pageno]; - } else { - pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n" - "Please increase it with coherent_pool= kernel parameter!\n", - (unsigned)pool->size / 1024); + 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; } - spin_unlock_irqrestore(&pool->lock, flags); return ptr; } static bool __in_atomic_pool(void *start, size_t size) { - struct dma_pool *pool = &atomic_pool; - void *end = start + size; - void *pool_start = pool->vaddr; - void *pool_end = pool->vaddr + pool->size; - - if (start < pool_start || start >= pool_end) - return false; - - if (end <= pool_end) - return true; - - WARN(1, "Wrong coherent size(%p-%p) from atomic pool(%p-%p)\n", - start, end - 1, pool_start, pool_end - 1); - - return false; + return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); } static int __free_from_pool(void *start, size_t size) { - struct dma_pool *pool = &atomic_pool; - unsigned long pageno, count; - unsigned long flags; - if (!__in_atomic_pool(start, size)) return 0; - pageno = (start - pool->vaddr) >> PAGE_SHIFT; - count = size >> PAGE_SHIFT; - - spin_lock_irqsave(&pool->lock, flags); - bitmap_clear(pool->bitmap, pageno, count); - spin_unlock_irqrestore(&pool->lock, flags); + gen_pool_free(atomic_pool, (unsigned long)start, size); return 1; } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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