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author | Paul Burton <paul.burton@mips.com> | 2019-02-15 22:03:04 +0000 |
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committer | Paul Burton <paul.burton@mips.com> | 2019-02-19 12:17:43 -0800 |
commit | d411da06abbe4c7cad0cc16b509d10b43da783a8 (patch) | |
tree | 65bd55f58f21cbd450fe78e981b916b087c622a9 | |
parent | 66b6572a142f2e9d7c4ffbcdaeb762d58664aa59 (diff) | |
download | linux-stable-d411da06abbe4c7cad0cc16b509d10b43da783a8.tar.gz linux-stable-d411da06abbe4c7cad0cc16b509d10b43da783a8.tar.bz2 linux-stable-d411da06abbe4c7cad0cc16b509d10b43da783a8.zip |
MIPS: dma-noncoherent: Remove bogus condition in dma_sync_phys()
Commit e36863a550da ("MIPS: HIGHMEM DMA on noncoherent MIPS32
processors") introduced code which:
1) Calculates an offset within a page, by ANDing an address
with ~PAGE_MASK.
2) Checks whether that offset is >= PAGE_SIZE.
This check can never evaluate true, making the code it guards
unreachable. smatch spots bogus arithmetic resulting from the
impossible condition, resulting in the following warning:
arch/mips/mm/dma-noncoherent.c:125
dma_sync_phys() warn: mask and shift to zero
Fix this by removing the impossible to satisfy condition & the
unreachable code it guards.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
-rw-r--r-- | arch/mips/mm/dma-noncoherent.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/mips/mm/dma-noncoherent.c b/arch/mips/mm/dma-noncoherent.c index f7e0fd6b7619..b57465733e87 100644 --- a/arch/mips/mm/dma-noncoherent.c +++ b/arch/mips/mm/dma-noncoherent.c @@ -120,13 +120,8 @@ static inline void dma_sync_phys(phys_addr_t paddr, size_t size, if (PageHighMem(page)) { void *addr; - if (offset + len > PAGE_SIZE) { - if (offset >= PAGE_SIZE) { - page += offset >> PAGE_SHIFT; - offset &= ~PAGE_MASK; - } + if (offset + len > PAGE_SIZE) len = PAGE_SIZE - offset; - } addr = kmap_atomic(page); dma_sync_virt(addr + offset, len, dir); |