From: Scott Wood <scottwood@freescale.com>
To: <agraf@suse.de>, <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: [PATCH 01/13] powerpc/e500: Save SPEFCSR in flush_spe_to_thread()
Date: Tue, 17 May 2011 18:35:51 -0500 [thread overview]
Message-ID: <20110517233551.GA3511@schlenkerla.am.freescale.net> (raw)
From: yu liu <yu.liu@freescale.com>
giveup_spe() saves the SPE state which is protected by MSR[SPE].
However, modifying SPEFSCR does not trap when MSR[SPE]=0.
And since SPEFSCR is already saved/restored in _switch(),
not all the callers want to save SPEFSCR again.
Thus, saving SPEFSCR should not belong to giveup_spe().
This patch moves SPEFSCR saving to flush_spe_to_thread(),
and cleans up the caller that needs to save SPEFSCR accordingly.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
---
This is a resending of http://patchwork.ozlabs.org/patch/88677/
Kumar, please ack to go via kvm. This is holding up the rest of the SPE
patches, which in turn are holding up the MMU patches due to both
touching the MSR update code.
arch/powerpc/kernel/head_fsl_booke.S | 2 --
arch/powerpc/kernel/process.c | 1 +
arch/powerpc/kernel/traps.c | 5 +----
3 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 5ecf54c..aede4f8 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -792,8 +792,6 @@ _GLOBAL(giveup_spe)
evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */
li r4,THREAD_ACC
evstddx evr6, r4, r3 /* save off accumulator */
- mfspr r6,SPRN_SPEFSCR
- stw r6,THREAD_SPEFSCR(r3) /* save spefscr register value */
beq 1f
lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
lis r3,MSR_SPE@h
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f74f355..138e7dd 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -213,6 +213,7 @@ void flush_spe_to_thread(struct task_struct *tsk)
#ifdef CONFIG_SMP
BUG_ON(tsk != current);
#endif
+ tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
giveup_spe(tsk);
}
preempt_enable();
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 5ddb801..742a0fb 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1356,10 +1356,7 @@ void SPEFloatingPointException(struct pt_regs *regs)
int code = 0;
int err;
- preempt_disable();
- if (regs->msr & MSR_SPE)
- giveup_spe(current);
- preempt_enable();
+ flush_spe_to_thread(current);
spefscr = current->thread.spefscr;
fpexc_mode = current->thread.fpexc_mode;
--
1.7.4.1
next reply other threads:[~2011-05-17 23:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-17 23:35 Scott Wood [this message]
2011-05-17 23:36 ` [PATCH 02/13] powerpc/e500: SPE register saving: take arbitrary struct offset Scott Wood
2011-05-19 6:05 ` Kumar Gala
2011-05-19 6:04 ` [PATCH 01/13] powerpc/e500: Save SPEFCSR in flush_spe_to_thread() Kumar Gala
2011-05-19 9:38 ` Alexander Graf
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=20110517233551.GA3511@schlenkerla.am.freescale.net \
--to=scottwood@freescale.com \
--cc=agraf@suse.de \
--cc=galak@kernel.crashing.org \
--cc=kvm-ppc@vger.kernel.org \
--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).