From: Christoph Hellwig hch@lst.de
'commit c32a77fd1878 ("swiotlb: factor out a nr_slots helper")'
Factor out a helper to find the number of slots for a given size.
Signed-off-by: Christoph Hellwig hch@lst.de Acked-by: Jianxiong Gao jxgao@google.com Tested-by: Jianxiong Gao jxgao@google.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: Jianxiong Gao jxgao@google.com --- include/linux/swiotlb.h | 1 + kernel/dma/swiotlb.c | 13 +++++++++---- 2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index cde3dc18e21a..ea8e2e28459d 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -28,6 +28,7 @@ enum swiotlb_force { * controllable. */ #define IO_TLB_SHIFT 11 +#define IO_TLB_SIZE (1 << IO_TLB_SHIFT)
extern void swiotlb_init(int verbose); int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 9fa71a91c235..70023393dd6b 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -179,6 +179,11 @@ static inline unsigned long io_tlb_offset(unsigned long val) return val & (IO_TLB_SEGSIZE - 1); }
+static inline unsigned long nr_slots(u64 val) +{ + return DIV_ROUND_UP(val, IO_TLB_SIZE); +} + /* * Early SWIOTLB allocation may be too early to allow an architecture to * perform the desired operations. This function allows the architecture to @@ -477,20 +482,20 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
tbl_dma_addr &= mask;
- offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; + offset_slots = nr_slots(tbl_dma_addr);
/* * Carefully handle integer overflow which can occur when mask == ~0UL. */ max_slots = mask + 1 - ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT + ? nr_slots(mask + 1) : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
/* * For mappings greater than or equal to a page, we limit the stride * (and hence alignment) to a page size. */ - nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; + nslots = nr_slots(alloc_size); if (alloc_size >= PAGE_SIZE) stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT)); else @@ -586,7 +591,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, enum dma_data_direction dir, unsigned long attrs) { unsigned long flags; - int i, count, nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; + int i, count, nslots = nr_slots(alloc_size); int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; phys_addr_t orig_addr = io_tlb_orig_addr[index];