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

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);'.

Cc: stable@vger.kernel.org
Signed-off-by: Alan Douglas <adouglas@cadence.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 2d9cc6dbfd78..e8b76b8e4b29 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -49,9 +49,8 @@ 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) {
@@ -68,10 +67,11 @@ EXPORT_SYMBOL(dma_alloc_coherent);
 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));
 }