diff options
Diffstat (limited to 'arch/riscv/lib/uaccess.S')
| -rw-r--r-- | arch/riscv/lib/uaccess.S | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index bceb0629e440..63bc691cff91 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -30,23 +30,23 @@ ENTRY(__asm_copy_from_user) * t0 - end of uncopied dst */ add t0, a0, a2 - bgtu a0, t0, 5f /* * Use byte copy only if too small. + * SZREG holds 4 for RV32 and 8 for RV64 */ - li a3, 8*SZREG /* size must be larger than size in word_copy */ + li a3, 9*SZREG /* size must be larger than size in word_copy */ bltu a2, a3, .Lbyte_copy_tail /* - * Copy first bytes until dst is align to word boundary. + * Copy first bytes until dst is aligned to word boundary. * a0 - start of dst * t1 - start of aligned dst */ addi t1, a0, SZREG-1 andi t1, t1, ~(SZREG-1) /* dst is already aligned, skip */ - beq a0, t1, .Lskip_first_bytes + beq a0, t1, .Lskip_align_dst 1: /* a5 - one byte for copying data */ fixup lb a5, 0(a1), 10f @@ -55,7 +55,7 @@ ENTRY(__asm_copy_from_user) addi a0, a0, 1 /* dst */ bltu a0, t1, 1b /* t1 - start of aligned dst */ -.Lskip_first_bytes: +.Lskip_align_dst: /* * Now dst is aligned. * Use shift-copy if src is misaligned. @@ -72,10 +72,9 @@ ENTRY(__asm_copy_from_user) * * a0 - start of aligned dst * a1 - start of aligned src - * a3 - a1 & mask:(SZREG-1) * t0 - end of aligned dst */ - addi t0, t0, -(8*SZREG-1) /* not to over run */ + addi t0, t0, -(8*SZREG) /* not to over run */ 2: fixup REG_L a4, 0(a1), 10f fixup REG_L a5, SZREG(a1), 10f @@ -97,7 +96,7 @@ ENTRY(__asm_copy_from_user) addi a1, a1, 8*SZREG bltu a0, t0, 2b - addi t0, t0, 8*SZREG-1 /* revert to original value */ + addi t0, t0, 8*SZREG /* revert to original value */ j .Lbyte_copy_tail .Lshift_copy: @@ -107,7 +106,7 @@ ENTRY(__asm_copy_from_user) * For misaligned copy we still perform aligned word copy, but * we need to use the value fetched from the previous iteration and * do some shifts. - * This is safe because reading less than a word size. + * This is safe because reading is less than a word size. * * a0 - start of aligned dst * a1 - start of src @@ -117,7 +116,7 @@ ENTRY(__asm_copy_from_user) */ /* calculating aligned word boundary for dst */ andi t1, t0, ~(SZREG-1) - /* Converting unaligned src to aligned arc */ + /* Converting unaligned src to aligned src */ andi a1, a1, ~(SZREG-1) /* @@ -125,11 +124,11 @@ 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 - /* Load the first word to combine with seceond word */ + /* Load the first word to combine with second word */ fixup REG_L a5, 0(a1), 10f 3: @@ -161,7 +160,7 @@ ENTRY(__asm_copy_from_user) * a1 - start of remaining src * t0 - end of remaining dst */ - bgeu a0, t0, 5f + bgeu a0, t0, .Lout_copy_user /* check if end of copy */ 4: fixup lb a5, 0(a1), 10f addi a1, a1, 1 /* src */ @@ -169,7 +168,7 @@ ENTRY(__asm_copy_from_user) addi a0, a0, 1 /* dst */ bltu a0, t0, 4b /* t0 - end of dst */ -5: +.Lout_copy_user: /* Disable access to user memory */ csrc CSR_STATUS, t6 li a0, 0 |