swiotlb: Fix the type of index

Fix the type of index from unsigned int to int since find_slots() might
return -1.

Fixes: 26a7e094783d ("swiotlb: refactor swiotlb_tbl_map_single")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Claire Chang <tientzu@chromium.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 0a5b6f7..8635a57 100644 (file)
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -499,7 +499,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
 {
        struct io_tlb_mem *mem = io_tlb_default_mem;
        unsigned int offset = swiotlb_align_offset(dev, orig_addr);
-       unsigned int index, i;
+       unsigned int i;
+       int index;
        phys_addr_t tlb_addr;
 
        if (!mem)