From: Max Filippov <jcmvbkbc@gmail.com>
To: linux-xtensa@linux-xtensa.org
Cc: Chris Zankel <chris@zankel.net>,
linux-kernel@vger.kernel.org, Max Filippov <jcmvbkbc@gmail.com>
Subject: [PATCH 03/10] xtensa: don't use a12 in strncpy_user
Date: Mon, 18 Oct 2021 22:17:09 -0700 [thread overview]
Message-ID: <20211019051716.4173-4-jcmvbkbc@gmail.com> (raw)
In-Reply-To: <20211019051716.4173-1-jcmvbkbc@gmail.com>
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>
---
arch/xtensa/lib/strncpy_user.S | 17 ++++++++---------
1 file 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:
--
2.20.1
next prev parent reply other threads:[~2021-10-19 5:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
2021-10-19 5:17 ` [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors Max Filippov
2021-10-19 5:17 ` [PATCH 02/10] xtensa: use a14 instead of a15 in inline assembly Max Filippov
2021-10-19 5:17 ` Max Filippov [this message]
2021-10-19 5:17 ` [PATCH 04/10] xtensa: don't use a12 in __xtensa_copy_user in call0 ABI Max Filippov
2021-10-19 5:17 ` [PATCH 05/10] xtensa: definitions for " Max Filippov
2021-10-19 5:17 ` [PATCH 06/10] xtensa: implement call0 ABI support in assembly Max Filippov
2021-10-19 5:17 ` [PATCH 07/10] xtensa: use register window specific opcodes only when present Max Filippov
2021-10-19 5:17 ` [PATCH 08/10] xtensa: only build windowed register support code when needed Max Filippov
2021-10-19 5:17 ` [PATCH 09/10] xtensa: remove unused variable wmask Max Filippov
2021-10-19 5:17 ` [PATCH 10/10] xtensa: move section symbols to asm/sections.h Max Filippov
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