xtensa: fix address checks in dma_{alloc,free}_coherent

commit 1ca49463c44c970b1ab1d71b0f268bfdf8427a7e upstream.

Virtual address is translated to the XCHAL_KSEG_CACHED region in the
dma_free_coherent, but is checked to be in the 0...XCHAL_KSEG_SIZE
range.

Change check for end of the range from 'addr >= X' to 'addr > X - 1' to
handle the case of X == 0.

Replace 'if (C) BUG();' construct with 'BUG_ON(C);'.

Signed-off-by: Alan Douglas <adouglas@cadence.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 2783fda..c055c91 100644 (file)
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -48,9 +48,8 @@ dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
 
        /* We currently don't support coherent memory outside KSEG */
 
-       if (ret < XCHAL_KSEG_CACHED_VADDR
-           || ret >= XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE)
-               BUG();
+       BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
+              ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
 
 
        if (ret != 0) {
@@ -66,10 +65,11 @@ dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
 void dma_free_coherent(struct device *hwdev, size_t size,
                         void *vaddr, dma_addr_t dma_handle)
 {
-       long addr=(long)vaddr+XCHAL_KSEG_CACHED_VADDR-XCHAL_KSEG_BYPASS_VADDR;
+       unsigned long addr = (unsigned long)vaddr +
+               XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
 
-       if (addr < 0 || addr >= XCHAL_KSEG_SIZE)
-               BUG();
+       BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
+              addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
 
        free_pages(addr, get_order(size));
 }