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| author | Michael Ellerman <michael@ellerman.id.au> | 2013-06-28 12:15:16 +0400 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-07-01 05:50:10 +0400 |
| commit | 330a1eb7775ba876dbd46b9885556e57f705e3d4 (patch) | |
| tree | 138693772ff043ec23e335a1ef42df7a7d5707ba /arch/powerpc/include/asm/switch_to.h | |
| parent | 2ac138ca21ad26c988ce7c91d27327f85beb7519 (diff) | |
| download | linux-330a1eb7775ba876dbd46b9885556e57f705e3d4.tar.xz | |
powerpc/perf: Core EBB support for 64-bit book3s
Add support for EBB (Event Based Branches) on 64-bit book3s. See the
included documentation for more details.
EBBs are a feature which allows the hardware to branch directly to a
specified user space address when a PMU event overflows. This can be
used by programs for self-monitoring with no kernel involvement in the
inner loop.
Most of the logic is in the generic book3s code, primarily to avoid a
proliferation of PMU callbacks.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/switch_to.h')
| -rw-r--r-- | arch/powerpc/include/asm/switch_to.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 200d763a0a67..49a13e0ef234 100644 --- a/arch/powerpc/include/asm/switch_to.h +++ b/arch/powerpc/include/asm/switch_to.h @@ -67,4 +67,18 @@ static inline void flush_spe_to_thread(struct task_struct *t) } #endif +static inline void clear_task_ebb(struct task_struct *t) +{ +#ifdef CONFIG_PPC_BOOK3S_64 + /* EBB perf events are not inherited, so clear all EBB state. */ + t->thread.bescr = 0; + t->thread.mmcr2 = 0; + t->thread.mmcr0 = 0; + t->thread.siar = 0; + t->thread.sdar = 0; + t->thread.sier = 0; + t->thread.used_ebb = 0; +#endif +} + #endif /* _ASM_POWERPC_SWITCH_TO_H */ |