From 330a1eb7775ba876dbd46b9885556e57f705e3d4 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Fri, 28 Jun 2013 18:15:16 +1000 Subject: 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/switch_to.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/powerpc/include/asm/switch_to.h') diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 200d763a0a6..49a13e0ef23 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 */ -- cgit v1.2.3-70-g09d2