x86: perf: Move RDPMC event flag to a common definition

In preparation to enable user counter access on arm64 and to move some of the user access handling to perf core, create a common event flag for user counter access and convert x86 to use it. Since the architecture specific flags start at the LSB, starting at the MSB for common flags.

Rob Herring committed 4 years ago

Commit 369461c1 parent d58071a3 files · +15 −6Browse files

Unified · Split

3 files

arch/x86/events/core.c +5 −5
arch/x86/events/perf_event.h +1 −1
include/linux/perf_event.h +9 −0

arch/x86/events/core.c+5−5

@@ -2476,7 +2476,7 @@ static int x86_pmu_event_init(struct perf_event *event) · 2475 unmodified lines
2476	2476
2477	2477	if (READ_ONCE(x86_pmu.attr_rdpmc) &&
2478	2478	!(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
2479		− event->hw.flags \|= PERF_X86_EVENT_RDPMC_ALLOWED;
	2479	+ event->hw.flags \|= PERF_EVENT_FLAG_USER_READ_CNT;
2480	2480
2481	2481	return err;
2482	2482	}
@@ -2510,7 +2510,7 @@ void perf_clear_dirty_counters(void) · 27 unmodified lines
2510	2510
2511	2511	static void x86_pmu_event_mapped(struct perf_event event, struct mm_struct mm)
2512	2512	{
2513		− if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
	2513	+ if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2514	2514	return;
2515	2515
2516	2516	/*
@@ -2531,7 +2531,7 @@ static void x86_pmu_event_mapped(struct perf_event event, struct mm_struct mm) · 14 unmodified lines
2531	2531
2532	2532	static void x86_pmu_event_unmapped(struct perf_event event, struct mm_struct mm)
2533	2533	{
2534		− if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
	2534	+ if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2535	2535	return;
2536	2536
2537	2537	if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
@@ -2542,7 +2542,7 @@ static int x86_pmu_event_idx(struct perf_event *event) · 4 unmodified lines
2542	2542	{
2543	2543	struct hw_perf_event *hwc = &event->hw;
2544	2544
2545		− if (!(hwc->flags & PERF_X86_EVENT_RDPMC_ALLOWED))
	2545	+ if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
2546	2546	return 0;
2547	2547
2548	2548	if (is_metric_idx(hwc->idx))
@@ -2725,7 +2725,7 @@ void arch_perf_update_userpage(struct perf_event *event, · 176 unmodified lines
2725	2725	userpg->cap_user_time = 0;
2726	2726	userpg->cap_user_time_zero = 0;
2727	2727	userpg->cap_user_rdpmc =
2728		− !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED);
	2728	+ !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);
2729	2729	userpg->pmc_width = x86_pmu.cntval_bits;
2730	2730
2731	2731	if (!using_native_sched_clock() \|\| !sched_clock_stable())

arch/x86/events/perf_event.h+1−1

@@ -74,7 +74,7 @@ static inline bool constraint_match(struct event_constraint *c, u64 ecode) · 73 unmodified lines
74	74	#define PERF_X86_EVENT_PEBS_NA_HSW 0x0010 /* haswell style datala, unknown */
75	75	#define PERF_X86_EVENT_EXCL 0x0020 /* HT exclusivity on counter */
76	76	#define PERF_X86_EVENT_DYNAMIC 0x0040 /* dynamic alloc'd constraint */
77		−#define PERF_X86_EVENT_RDPMC_ALLOWED 0x0080 /* grant rdpmc permission */
	77	+
78	78	#define PERF_X86_EVENT_EXCL_ACCT 0x0100 /* accounted EXCL event */
79	79	#define PERF_X86_EVENT_AUTO_RELOAD 0x0200 /* use PEBS auto-reload */
80	80	#define PERF_X86_EVENT_LARGE_PEBS 0x0400 /* use large PEBS */

include/linux/perf_event.h+9−0

@@ -129,6 +129,15 @@ struct hw_perf_event_extra { · 128 unmodified lines
129	129	int idx; /* index in shared_regs->regs[] */
130	130	};
131	131
	132	+/**
	133	+ * hw_perf_event::flag values
	134	+ *
	135	+ * PERF_EVENT_FLAG_ARCH bits are reserved for architecture-specific
	136	+ * usage.
	137	+ */
	138	+#define PERF_EVENT_FLAG_ARCH 0x0000ffff
	139	+#define PERF_EVENT_FLAG_USER_READ_CNT 0x80000000
	140	+
132	141	/**
133	142	* struct hw_perf_event - performance event hardware details:
134	143	*/