summaryrefslogtreecommitdiff
path: root/arch/riscv/lib/uaccess.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/lib/uaccess.S')
-rw-r--r--arch/riscv/lib/uaccess.S27
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