diff options
Diffstat (limited to 'drivers/base/dma-contiguous.c')
| -rw-r--r-- | drivers/base/dma-contiguous.c | 77 |
1 files changed, 53 insertions, 24 deletions
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index 5f62c284072c..ad8a85bf852f 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -38,6 +38,7 @@ struct cma { unsigned long base_pfn; unsigned long count; unsigned long *bitmap; + unsigned int order_per_bit; /* Order of pages represented by one bit */ struct mutex lock; }; @@ -157,9 +158,37 @@ void __init dma_contiguous_reserve(phys_addr_t limit) static DEFINE_MUTEX(cma_mutex); +static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order) +{ + return (1UL << (align_order >> cma->order_per_bit)) - 1; +} + +static unsigned long cma_bitmap_maxno(struct cma *cma) +{ + return cma->count >> cma->order_per_bit; +} + +static unsigned long cma_bitmap_pages_to_bits(struct cma *cma, + unsigned long pages) +{ + return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit; +} + +static void cma_clear_bitmap(struct cma *cma, unsigned long pfn, int count) +{ + unsigned long bitmap_no, bitmap_count; + + bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit; + bitmap_count = cma_bitmap_pages_to_bits(cma, count); + + mutex_lock(&cma->lock); + bitmap_clear(cma->bitmap, bitmap_no, bitmap_count); + mutex_unlock(&cma->lock); +} + static int __init cma_activate_area(struct cma *cma) { - int bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long); + int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long); unsigned long base_pfn = cma->base_pfn, pfn = base_pfn; unsigned i = cma->count >> pageblock_order; struct zone *zone; @@ -215,9 +244,9 @@ static int __init cma_init_reserved_areas(void) core_initcall(cma_init_reserved_areas); static int __init __dma_contiguous_reserve_area(phys_addr_t size, - phys_addr_t base, phys_addr_t limit, - phys_addr_t alignment, - struct cma **res_cma, bool fixed) + phys_addr_t base, phys_addr_t limit, + phys_addr_t alignment, unsigned int order_per_bit, + struct cma **res_cma, bool fixed) { struct cma *cma = &cma_areas[cma_area_count]; int ret = 0; @@ -249,6 +278,10 @@ static int __init __dma_contiguous_reserve_area(phys_addr_t size, size = ALIGN(size, alignment); limit &= ~(alignment - 1); + /* size should be aligned with order_per_bit */ + if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit)) + return -EINVAL; + /* Reserve memory */ if (base && fixed) { if (memblock_is_region_reserved(base, size) || @@ -273,6 +306,7 @@ static int __init __dma_contiguous_reserve_area(phys_addr_t size, */ cma->base_pfn = PFN_DOWN(base); cma->count = size >> PAGE_SHIFT; + cma->order_per_bit = order_per_bit; *res_cma = cma; cma_area_count++; @@ -308,7 +342,7 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, { int ret; - ret = __dma_contiguous_reserve_area(size, base, limit, 0, + ret = __dma_contiguous_reserve_area(size, base, limit, 0, 0, res_cma, fixed); if (ret) return ret; @@ -320,17 +354,11 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, return 0; } -static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count) -{ - mutex_lock(&cma->lock); - bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count); - mutex_unlock(&cma->lock); -} - static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count, unsigned int align) { - unsigned long mask, pfn, pageno, start = 0; + unsigned long mask, pfn, start = 0; + unsigned long bitmap_maxno, bitmap_no, bitmap_count; struct page *page = NULL; int ret; @@ -343,18 +371,19 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count, if (!count) return NULL; - mask = (1 << align) - 1; - + mask = cma_bitmap_aligned_mask(cma, align); + bitmap_maxno = cma_bitmap_maxno(cma); + bitmap_count = cma_bitmap_pages_to_bits(cma, count); for (;;) { mutex_lock(&cma->lock); - pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count, - start, count, mask); - if (pageno >= cma->count) { + bitmap_no = bitmap_find_next_zero_area(cma->bitmap, + bitmap_maxno, start, bitmap_count, mask); + if (bitmap_no >= bitmap_maxno) { mutex_unlock(&cma->lock); break; } - bitmap_set(cma->bitmap, pageno, count); + bitmap_set(cma->bitmap, bitmap_no, bitmap_count); /* * It's safe to drop the lock here. We've marked this region for * our exclusive use. If the migration fails we will take the @@ -362,7 +391,7 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count, */ mutex_unlock(&cma->lock); - pfn = cma->base_pfn + pageno; + pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit); mutex_lock(&cma_mutex); ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA); mutex_unlock(&cma_mutex); @@ -370,14 +399,14 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count, page = pfn_to_page(pfn); break; } else if (ret != -EBUSY) { - clear_cma_bitmap(cma, pfn, count); + cma_clear_bitmap(cma, pfn, count); break; } - clear_cma_bitmap(cma, pfn, count); + cma_clear_bitmap(cma, pfn, count); pr_debug("%s(): memory range at %p is busy, retrying\n", __func__, pfn_to_page(pfn)); /* try again with a bit different memory target */ - start = pageno + mask + 1; + start = bitmap_no + mask + 1; } pr_debug("%s(): returned %p\n", __func__, page); @@ -424,7 +453,7 @@ static bool __dma_release_from_contiguous(struct cma *cma, struct page *pages, VM_BUG_ON(pfn + count > cma->base_pfn + cma->count); free_contig_range(pfn, count); - clear_cma_bitmap(cma, pfn, count); + cma_clear_bitmap(cma, pfn, count); return true; } |
