Merge v5.14-rc3 into usb-next

[linux-2.6-microblaze.git] / arch / riscv / lib / uaccess.S

diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S
index bceb062..63bc691 100644 (file)
--- 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