From: Michael Ellerman <michael@ellerman.id.au>
To: <linuxppc-dev@ozlabs.org>
Subject: [PATCH] powerpc: Partial revert of "Context switch more PMU related SPRs"
Date: Thu, 6 Jun 2013 14:03:36 +1000 [thread overview]
Message-ID: <1370491416-1807-1-git-send-email-michael@ellerman.id.au> (raw)
In commit 59affcd I added context switching of more PMU SPRs, because
they are potentially exposed to userspace on Power8. However despite me
being a smart arse in the commit message it's actually not correct. In
particular it interacts badly with a global perf record.
We will have to do something more complicated, but that will have to
wait for 3.11.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
arch/powerpc/kernel/entry_64.S | 28 ----------------------------
1 file changed, 28 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 246b11c..8741c85 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -465,20 +465,6 @@ BEGIN_FTR_SECTION
std r0, THREAD_EBBHR(r3)
mfspr r0, SPRN_EBBRR
std r0, THREAD_EBBRR(r3)
-
- /* PMU registers made user read/(write) by EBB */
- mfspr r0, SPRN_SIAR
- std r0, THREAD_SIAR(r3)
- mfspr r0, SPRN_SDAR
- std r0, THREAD_SDAR(r3)
- mfspr r0, SPRN_SIER
- std r0, THREAD_SIER(r3)
- mfspr r0, SPRN_MMCR0
- std r0, THREAD_MMCR0(r3)
- mfspr r0, SPRN_MMCR2
- std r0, THREAD_MMCR2(r3)
- mfspr r0, SPRN_MMCRA
- std r0, THREAD_MMCRA(r3)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
#endif
@@ -581,20 +567,6 @@ BEGIN_FTR_SECTION
ld r0, THREAD_EBBRR(r4)
mtspr SPRN_EBBRR, r0
- /* PMU registers made user read/(write) by EBB */
- ld r0, THREAD_SIAR(r4)
- mtspr SPRN_SIAR, r0
- ld r0, THREAD_SDAR(r4)
- mtspr SPRN_SDAR, r0
- ld r0, THREAD_SIER(r4)
- mtspr SPRN_SIER, r0
- ld r0, THREAD_MMCR0(r4)
- mtspr SPRN_MMCR0, r0
- ld r0, THREAD_MMCR2(r4)
- mtspr SPRN_MMCR2, r0
- ld r0, THREAD_MMCRA(r4)
- mtspr SPRN_MMCRA, r0
-
ld r0,THREAD_TAR(r4)
mtspr SPRN_TAR,r0
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
--
1.7.10.4
next reply other threads:[~2013-06-06 4:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-06 4:03 Michael Ellerman [this message]
2013-06-10 4:18 ` [PATCH] powerpc: Partial revert of "Context switch more PMU related SPRs" Anshuman Khandual
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