From: Lijun Pan <ljp@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Lijun Pan <ljp@linux.ibm.com>
Subject: [RFC] powerpc/pseries/hcall: remove the save/restore of CR
Date: Thu, 26 Sep 2019 22:48:46 -0500 [thread overview]
Message-ID: <20190927034846.73066-1-ljp@linux.ibm.com> (raw)
According to the PAPR, hcalls should not modify the Condition
Register fields, hence save/restore the CR is not necessary.
Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
---
arch/powerpc/platforms/pseries/hvCall.S | 36 -------------------------
1 file changed, 36 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index 2136e42833af..b26a79331994 100644
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -105,13 +105,9 @@ END_FTR_SECTION(0, 1); \
_GLOBAL_TOC(plpar_hcall_norets)
HMT_MEDIUM
- mfcr r0
- stw r0,8(r1)
HCALL_BRANCH(plpar_hcall_norets_trace)
HVSC /* invoke the hypervisor */
- lwz r0,8(r1)
- mtcrf 0xff,r0
blr /* return r3 = status */
#ifdef CONFIG_TRACEPOINTS
@@ -119,17 +115,12 @@ plpar_hcall_norets_trace:
HCALL_INST_PRECALL(R4)
HVSC
HCALL_INST_POSTCALL_NORETS
- lwz r0,8(r1)
- mtcrf 0xff,r0
blr
#endif
_GLOBAL_TOC(plpar_hcall)
HMT_MEDIUM
- mfcr r0
- stw r0,8(r1)
-
HCALL_BRANCH(plpar_hcall_trace)
std r4,STK_PARAM(R4)(r1) /* Save ret buffer */
@@ -149,9 +140,6 @@ _GLOBAL_TOC(plpar_hcall)
std r6, 16(r12)
std r7, 24(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr /* return r3 = status */
#ifdef CONFIG_TRACEPOINTS
@@ -178,9 +166,6 @@ plpar_hcall_trace:
HCALL_INST_POSTCALL(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr
#endif
@@ -193,9 +178,6 @@ plpar_hcall_trace:
_GLOBAL(plpar_hcall_raw)
HMT_MEDIUM
- mfcr r0
- stw r0,8(r1)
-
std r4,STK_PARAM(R4)(r1) /* Save ret buffer */
mr r4,r5
@@ -213,17 +195,11 @@ _GLOBAL(plpar_hcall_raw)
std r6, 16(r12)
std r7, 24(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr /* return r3 = status */
_GLOBAL_TOC(plpar_hcall9)
HMT_MEDIUM
- mfcr r0
- stw r0,8(r1)
-
HCALL_BRANCH(plpar_hcall9_trace)
std r4,STK_PARAM(R4)(r1) /* Save ret buffer */
@@ -252,9 +228,6 @@ _GLOBAL_TOC(plpar_hcall9)
std r11,56(r12)
std r0, 64(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr /* return r3 = status */
#ifdef CONFIG_TRACEPOINTS
@@ -290,9 +263,6 @@ plpar_hcall9_trace:
HCALL_INST_POSTCALL(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr
#endif
@@ -300,9 +270,6 @@ plpar_hcall9_trace:
_GLOBAL(plpar_hcall9_raw)
HMT_MEDIUM
- mfcr r0
- stw r0,8(r1)
-
std r4,STK_PARAM(R4)(r1) /* Save ret buffer */
mr r4,r5
@@ -329,7 +296,4 @@ _GLOBAL(plpar_hcall9_raw)
std r11,56(r12)
std r0, 64(r12)
- lwz r0,8(r1)
- mtcrf 0xff,r0
-
blr /* return r3 = status */
--
2.22.0
next reply other threads:[~2019-09-27 3:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-27 3:48 Lijun Pan [this message]
2019-09-27 18:48 ` [RFC] powerpc/pseries/hcall: remove the save/restore of CR Paul Clarke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190927034846.73066-1-ljp@linux.ibm.com \
--to=ljp@linux.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).