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authorMax Filippov <jcmvbkbc@gmail.com>2021-07-25 16:31:34 -0700
committerMax Filippov <jcmvbkbc@gmail.com>2021-10-18 22:19:34 -0700
commitd191323bc02370667fede74228135440efd98d2b (patch)
treef1fa31aaeb0dea91d6f2a9e65c8c39a3a367f1fd /arch/xtensa
parentxtensa: use a14 instead of a15 in inline assembly (diff)
downloadlinux-dev-d191323bc02370667fede74228135440efd98d2b.tar.xz
linux-dev-d191323bc02370667fede74228135440efd98d2b.zip
xtensa: don't use a12 in strncpy_user
a12 is callee-saved register in xtensa call0 ABI, so a function must not change it. a10 is not used in this function at all, use it instead of a12 to avoid saving/restoring it. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/lib/strncpy_user.S17
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/xtensa/lib/strncpy_user.S b/arch/xtensa/lib/strncpy_user.S
index 4faf46fe3f38..0731912227d3 100644
--- a/arch/xtensa/lib/strncpy_user.S
+++ b/arch/xtensa/lib/strncpy_user.S
@@ -45,7 +45,6 @@
# a9/ tmp
# a10/ tmp
# a11/ dst
-# a12/ tmp
.text
ENTRY(__strncpy_user)
@@ -61,7 +60,7 @@ ENTRY(__strncpy_user)
bbsi.l a3, 0, .Lsrc1mod2 # if only 8-bit aligned
bbsi.l a3, 1, .Lsrc2mod4 # if only 16-bit aligned
.Lsrcaligned: # return here when src is word-aligned
- srli a12, a4, 2 # number of loop iterations with 4B per loop
+ srli a10, a4, 2 # number of loop iterations with 4B per loop
movi a9, 3
bnone a11, a9, .Laligned
j .Ldstunaligned
@@ -102,11 +101,11 @@ EX(10f) s8i a9, a11, 0 # store byte 0
.byte 0 # (0 mod 4 alignment for LBEG)
.Laligned:
#if XCHAL_HAVE_LOOPS
- loopnez a12, .Loop1done
+ loopnez a10, .Loop1done
#else
- beqz a12, .Loop1done
- slli a12, a12, 2
- add a12, a12, a11 # a12 = end of last 4B chunck
+ beqz a10, .Loop1done
+ slli a10, a10, 2
+ add a10, a10, a11 # a10 = end of last 4B chunck
#endif
.Loop1:
EX(11f) l32i a9, a3, 0 # get word from src
@@ -118,7 +117,7 @@ EX(10f) s32i a9, a11, 0 # store word to dst
bnone a9, a8, .Lz3 # if byte 3 is zero
addi a11, a11, 4 # advance dst pointer
#if !XCHAL_HAVE_LOOPS
- blt a11, a12, .Loop1
+ blt a11, a10, .Loop1
#endif
.Loop1done:
@@ -185,7 +184,7 @@ EX(10f) s8i a9, a11, 2
loopnez a4, .Lunalignedend
#else
beqz a4, .Lunalignedend
- add a12, a11, a4 # a12 = ending address
+ add a10, a11, a4 # a10 = ending address
#endif /* XCHAL_HAVE_LOOPS */
.Lnextbyte:
EX(11f) l8ui a9, a3, 0
@@ -194,7 +193,7 @@ EX(10f) s8i a9, a11, 0
beqz a9, .Lunalignedend
addi a11, a11, 1
#if !XCHAL_HAVE_LOOPS
- blt a11, a12, .Lnextbyte
+ blt a11, a10, .Lnextbyte
#endif
.Lunalignedend: