From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH 10/12] powerpc: Fix register clobbering when accumulating stolen time
Date: Fri, 2 Mar 2012 20:35:20 +1100 [thread overview]
Message-ID: <1330680922-6894-11-git-send-email-benh@kernel.crashing.org> (raw)
In-Reply-To: <1330680922-6894-1-git-send-email-benh@kernel.crashing.org>
When running under a hypervisor that supports stolen time accounting,
we may call C code from the macro EXCEPTION_PROLOG_COMMON in the
exception entry path, which clobbers CR0.
However, the FPU and vector traps rely on CR0 indicating whether we
are coming from userspace or kernel to decide what to do.
So we need to restore that value after the C call
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/include/asm/ppc_asm.h | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 368f72f..50f73aa 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -60,6 +60,8 @@ BEGIN_FW_FTR_SECTION; \
cmpd cr1,r11,r10; \
beq+ cr1,33f; \
bl .accumulate_stolen_time; \
+ ld r12,_MSR(r1); \
+ andi. r10,r12,MSR_PR; /* Restore cr0 (coming from user) */ \
33: \
END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
--
1.7.9
next prev parent reply other threads:[~2012-03-02 9:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-02 9:35 [PATCH 00/12] powerpc: Low level spring cleaning Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 01/12] powerpc: Remove legacy iSeries bits from assembly files Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 02/12] powerpc: Use the same interrupt prolog for perfmon as other interrupts Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 03/12] powerpc: Rework runlatch code Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 04/12] powerpc: Improve 64-bit syscall entry/exit Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 05/12] powerpc: Improve behaviour of irq tracing on 64-bit exception entry Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 06/12] powerpc: Disable interrupts in 64-bit kernel FP and vector faults Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 07/12] powerpc: Call do_page_fault() with interrupts off Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 08/12] powerpc: Add support for page fault retry and fatal signals Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 09/12] powerpc/xmon: Add display of soft & hard irq states Benjamin Herrenschmidt
2012-03-02 9:35 ` Benjamin Herrenschmidt [this message]
2012-03-02 9:35 ` [PATCH 11/12] powerpc: Replace mfmsr instructions with load from PACA kernel_msr field Benjamin Herrenschmidt
2012-03-02 9:35 ` [PATCH 12/12] powerpc: Rework lazy-interrupt handling Benjamin Herrenschmidt
2012-03-04 23:11 ` Benjamin Herrenschmidt
[not found] ` <1330680922-6894-4-git-send-email-benh__48089.0872575857$1330681158$gmane$org@kernel.crashing.org>
2012-04-05 21:38 ` [PATCH 03/12] powerpc: Rework runlatch code Andreas Schwab
2012-04-05 22:12 ` Benjamin Herrenschmidt
2012-04-05 23:05 ` Andreas Schwab
2012-04-11 0:46 ` Benjamin Herrenschmidt
2012-04-11 9:09 ` Andreas Schwab
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=1330680922-6894-11-git-send-email-benh@kernel.crashing.org \
--to=benh@kernel.crashing.org \
--cc=linuxppc-dev@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).