From: Michael Ellerman Date: Wed, 5 Jun 2013 18:03:36 +0000 (+0000) Subject: powerpc: Partial revert of "Context switch more PMU related SPRs" X-Git-Tag: firefly_0821_release~3680^2~335^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b11ae95100f7061b39a15e5c1ecbf862464ac4b4;p=firefly-linux-kernel-4.4.55.git powerpc: Partial revert of "Context switch more PMU related SPRs" 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 Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 246b11c4fe7e..8741c854e03d 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)