arm64: Fix DMA range invalidation for cache line unaligned buffers

If the buffer needing cache invalidation for inbound DMA does start or
end on a cache line aligned address, we need to use the non-destructive
clean&invalidate operation. This issue was introduced by commit
7363590d2c46 (arm64: Implement coherent DMA API based on swiotlb).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Jon Medhurst (Tixy) <tixy@linaro.org>

diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index e803a62e0e45e317e72def339358a4c78f608f48..fda756875fa63e0fca640e99ca9a20ed789a20f4 100644 (file)
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -183,12 +183,19 @@ ENTRY(__inval_cache_range)
 __dma_inv_range:
        dcache_line_size x2, x3
        sub     x3, x2, #1
-       bic     x0, x0, x3
+       tst     x1, x3                          // end cache line aligned?
        bic     x1, x1, x3
-1:     dc      ivac, x0                        // invalidate D / U line
-       add     x0, x0, x2
+       b.eq    1f
+       dc      civac, x1                       // clean & invalidate D / U line
+1:     tst     x0, x3                          // start cache line aligned?
+       bic     x0, x0, x3
+       b.eq    2f
+       dc      civac, x0                       // clean & invalidate D / U line
+       b       3f
+2:     dc      ivac, x0                        // invalidate D / U line
+3:     add     x0, x0, x2
        cmp     x0, x1
-       b.lo    1b
+       b.lo    2b
        dsb     sy
        ret
 ENDPROC(__inval_cache_range)