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.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-perf-users@vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211208201124.310740-2-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 38b2c77..68dea7c 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2476,7 +2476,7 @@ static int x86_pmu_event_init(struct perf_event *event)
 
        if (READ_ONCE(x86_pmu.attr_rdpmc) &&
            !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
-               event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED;
+               event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
 
        return err;
 }
@@ -2510,7 +2510,7 @@ void perf_clear_dirty_counters(void)
 
 static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
 {
-       if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
+       if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return;
 
        /*
@@ -2531,7 +2531,7 @@ static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
 
 static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
 {
-       if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
+       if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return;
 
        if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
@@ -2542,7 +2542,7 @@ static int x86_pmu_event_idx(struct perf_event *event)
 {
        struct hw_perf_event *hwc = &event->hw;
 
-       if (!(hwc->flags & PERF_X86_EVENT_RDPMC_ALLOWED))
+       if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return 0;
 
        if (is_metric_idx(hwc->idx))
@@ -2725,7 +2725,7 @@ void arch_perf_update_userpage(struct perf_event *event,
        userpg->cap_user_time = 0;
        userpg->cap_user_time_zero = 0;
        userpg->cap_user_rdpmc =
-               !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED);
+               !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);
        userpg->pmc_width = x86_pmu.cntval_bits;
 
        if (!using_native_sched_clock() || !sched_clock_stable())

diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 5480db2..9d376e5 100644 (file)
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -74,7 +74,7 @@ static inline bool constraint_match(struct event_constraint *c, u64 ecode)
 #define PERF_X86_EVENT_PEBS_NA_HSW     0x0010 /* haswell style datala, unknown */
 #define PERF_X86_EVENT_EXCL            0x0020 /* HT exclusivity on counter */
 #define PERF_X86_EVENT_DYNAMIC         0x0040 /* dynamic alloc'd constraint */
-#define PERF_X86_EVENT_RDPMC_ALLOWED   0x0080 /* grant rdpmc permission */
+
 #define PERF_X86_EVENT_EXCL_ACCT       0x0100 /* accounted EXCL event */
 #define PERF_X86_EVENT_AUTO_RELOAD     0x0200 /* use PEBS auto-reload */
 #define PERF_X86_EVENT_LARGE_PEBS      0x0400 /* use large PEBS */

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 0dcfd26..ba94679 100644 (file)
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -130,6 +130,15 @@ struct hw_perf_event_extra {
 };
 
 /**
+ * hw_perf_event::flag values
+ *
+ * PERF_EVENT_FLAG_ARCH bits are reserved for architecture-specific
+ * usage.
+ */
+#define PERF_EVENT_FLAG_ARCH                   0x0000ffff
+#define PERF_EVENT_FLAG_USER_READ_CNT          0x80000000
+
+/**
  * struct hw_perf_event - performance event hardware details:
  */
 struct hw_perf_event {