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: ca6eaaa210de ("riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S
index 8bbeca8..2798768 100644 (file)
--- a/arch/riscv/lib/uaccess.S
+++ b/arch/riscv/lib/uaccess.S
@@ -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