diff options
| author | Neil Leeder <nleeder@codeaurora.org> | 2014-07-11 14:06:02 -0400 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 20:48:15 -0700 |
| commit | b70837c8b27f553abe1722e2f52f8adad4cb012f (patch) | |
| tree | f0c59120037fcde382454c29178efebd15af5606 /arch/arm64/kernel | |
| parent | a585783352a95554b39461d50110e96ceb31d3bd (diff) | |
Perf: arm64: add perf user-mode permissions
Allow user-mode applications to use the performance
counters for debugging and performance analysis.
Change-Id: I3985c0fccfe925c50ace5d33435f6f69b31e07a5
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
[satyap: trivial merge conflict resolution]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/perf_debug.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/perf_event.c | 19 |
2 files changed, 19 insertions, 3 deletions
diff --git a/arch/arm64/kernel/perf_debug.c b/arch/arm64/kernel/perf_debug.c index b0b4da762f95..4ae6c598e9d5 100644 --- a/arch/arm64/kernel/perf_debug.c +++ b/arch/arm64/kernel/perf_debug.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2014, The Linux Foundation. All rights reserved. +/* Copyright (c) 2014-2016, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and @@ -24,6 +24,7 @@ static char *descriptions = " 0 arm64: perf: add debug patch logging framework\n" " 1 Perf: arm64: Add L1 counters to tracepoints\n" + " 5 Perf: arm64: add perf user-mode permissions\n" ; static ssize_t desc_read(struct file *fp, char __user *buf, diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index c7491471b04d..8f466a07ee5f 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -561,6 +561,22 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event, return 0; } +#ifdef CONFIG_PERF_EVENTS_USERMODE +static void armv8pmu_init_usermode(void) +{ + /* Enable access from userspace. */ + asm volatile("msr pmuserenr_el0, %0" :: "r" (0xF)); + +} +#else +static inline void armv8pmu_init_usermode(void) +{ + /* Disable access from userspace. */ + asm volatile("msr pmuserenr_el0, %0" :: "r" (0)); + +} +#endif + static void armv8pmu_reset(void *info) { struct arm_pmu *cpu_pmu = (struct arm_pmu *)info; @@ -575,8 +591,7 @@ static void armv8pmu_reset(void *info) /* Initialize & Reset PMNC: C and P bits. */ armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMCR_P | ARMV8_PMCR_C); - /* Disable access from userspace. */ - asm volatile("msr pmuserenr_el0, %0" :: "r" (0)); + armv8pmu_init_usermode(); } static int armv8_pmuv3_map_event(struct perf_event *event) |