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riscv: __asm_copy_to-from_user: Fix: fail on RV32 

Had a bug when converting bytes to bits when the cpu was rv32.

The a3 contains the number of bytes and multiple of 8
would be the bits. The LGREG is holding 2 for RV32 and 3 for
RV32, so to achieve multiple of 8 it must always be constant 3.
The 2 was mistakenly used for rv32.

Signed-off-by: Akira Tsukamoto <akira.tsukamoto@gmail.com>
Fixes: ca6eaaa210 ("riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Akira Tsukamoto 2021-07-20 17:51:45 +09:00 committed by Palmer Dabbelt
parent 6010d300f9
commit 22b5f16ffe
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arch/riscv/lib/uaccess.S
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@ -125,7 +125,7 @@ ENTRY(__asm_copy_from_user)
* t3 - prev shift
* t4 - current shift
*/
slli t3, a3, LGREG
slli t3, a3, 3 /* converting bytes in a3 to bits */
li a5, SZREG*8
sub t4, a5, t3