arm64: mm: Fix operands of clz in __flush_dcache_all

The format of the lower 32-bits of the 64-bit operand to 'dc cisw' is
unchanged from ARMv7 architecture and the upper bits are RES0. This
implies that the 'way' field of the operand of 'dc cisw' occupies the
bit-positions [31 .. (32-A)]. Due to the use of 64-bit extended operands
to 'clz', the existing implementation of __flush_dcache_all is incorrectly
placing the 'way' field in the bit-positions [63 .. (64-A)].

Signed-off-by: Sukanto Ghosh <sghosh@apm.com>
Tested-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org

diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index abe69b80cf7f674d9eb25b884a33e78a223aeb65..48a386094fa3cf98a7e8af3ae8d3b9ba5cce6c21 100644 (file)
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -52,7 +52,7 @@ loop1:
        add     x2, x2, #4                      // add 4 (line length offset)
        mov     x4, #0x3ff
        and     x4, x4, x1, lsr #3              // find maximum number on the way size
-       clz     x5, x4                          // find bit position of way size increment
+       clz     w5, w4                          // find bit position of way size increment
        mov     x7, #0x7fff
        and     x7, x7, x1, lsr #13             // extract max number of the index size
 loop2: