Messages in this thread | | | From | Rob Herring <> | Date | Tue, 11 Jan 2022 16:43:41 -0600 | Subject | Re: [PATCH v8] libperf: Add arm64 support to perf_mmap__read_self() |
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On Tue, Dec 14, 2021 at 3:56 PM Rob Herring <robh@kernel.org> wrote: > > Add the arm64 variants for read_perf_counter() and read_timestamp(). > Unfortunately the counter number is encoded into the instruction, so the > code is a bit verbose to enumerate all possible counters. > > Signed-off-by: Rob Herring <robh@kernel.org> > --- > v8: > - Set attr.config1 to request user access on arm64 > v7: > - Move enabling of libperf user read test for arm64 to this patch > --- > tools/lib/perf/mmap.c | 98 +++++++++++++++++++++++++++++++ > tools/lib/perf/tests/test-evsel.c | 5 +- > 2 files changed, 102 insertions(+), 1 deletion(-)
Ping!
> > diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c > index c89dfa5f67b3..7ee3eb9f5e27 100644 > --- a/tools/lib/perf/mmap.c > +++ b/tools/lib/perf/mmap.c > @@ -13,6 +13,7 @@ > #include <internal/lib.h> > #include <linux/kernel.h> > #include <linux/math64.h> > +#include <linux/stringify.h> > #include "internal.h" > > void perf_mmap__init(struct perf_mmap *map, struct perf_mmap *prev, > @@ -294,6 +295,103 @@ static u64 read_timestamp(void) > > return low | ((u64)high) << 32; > } > +#elif defined(__aarch64__) > +#define read_sysreg(r) ({ \ > + u64 __val; \ > + asm volatile("mrs %0, " __stringify(r) : "=r" (__val)); \ > + __val; \ > +}) > + > +static u64 read_pmccntr(void) > +{ > + return read_sysreg(pmccntr_el0); > +} > + > +#define PMEVCNTR_READ(idx) \ > + static u64 read_pmevcntr_##idx(void) { \ > + return read_sysreg(pmevcntr##idx##_el0); \ > + } > + > +PMEVCNTR_READ(0); > +PMEVCNTR_READ(1); > +PMEVCNTR_READ(2); > +PMEVCNTR_READ(3); > +PMEVCNTR_READ(4); > +PMEVCNTR_READ(5); > +PMEVCNTR_READ(6); > +PMEVCNTR_READ(7); > +PMEVCNTR_READ(8); > +PMEVCNTR_READ(9); > +PMEVCNTR_READ(10); > +PMEVCNTR_READ(11); > +PMEVCNTR_READ(12); > +PMEVCNTR_READ(13); > +PMEVCNTR_READ(14); > +PMEVCNTR_READ(15); > +PMEVCNTR_READ(16); > +PMEVCNTR_READ(17); > +PMEVCNTR_READ(18); > +PMEVCNTR_READ(19); > +PMEVCNTR_READ(20); > +PMEVCNTR_READ(21); > +PMEVCNTR_READ(22); > +PMEVCNTR_READ(23); > +PMEVCNTR_READ(24); > +PMEVCNTR_READ(25); > +PMEVCNTR_READ(26); > +PMEVCNTR_READ(27); > +PMEVCNTR_READ(28); > +PMEVCNTR_READ(29); > +PMEVCNTR_READ(30); > + > +/* > + * Read a value direct from PMEVCNTR<idx> > + */ > +static u64 read_perf_counter(unsigned int counter) > +{ > + static u64 (* const read_f[])(void) = { > + read_pmevcntr_0, > + read_pmevcntr_1, > + read_pmevcntr_2, > + read_pmevcntr_3, > + read_pmevcntr_4, > + read_pmevcntr_5, > + read_pmevcntr_6, > + read_pmevcntr_7, > + read_pmevcntr_8, > + read_pmevcntr_9, > + read_pmevcntr_10, > + read_pmevcntr_11, > + read_pmevcntr_13, > + read_pmevcntr_12, > + read_pmevcntr_14, > + read_pmevcntr_15, > + read_pmevcntr_16, > + read_pmevcntr_17, > + read_pmevcntr_18, > + read_pmevcntr_19, > + read_pmevcntr_20, > + read_pmevcntr_21, > + read_pmevcntr_22, > + read_pmevcntr_23, > + read_pmevcntr_24, > + read_pmevcntr_25, > + read_pmevcntr_26, > + read_pmevcntr_27, > + read_pmevcntr_28, > + read_pmevcntr_29, > + read_pmevcntr_30, > + read_pmccntr > + }; > + > + if (counter < ARRAY_SIZE(read_f)) > + return (read_f[counter])(); > + > + return 0; > +} > + > +static u64 read_timestamp(void) { return read_sysreg(cntvct_el0); } > + > #else > static u64 read_perf_counter(unsigned int counter __maybe_unused) { return 0; } > static u64 read_timestamp(void) { return 0; } > diff --git a/tools/lib/perf/tests/test-evsel.c b/tools/lib/perf/tests/test-evsel.c > index 33ae9334861a..89be89afb24d 100644 > --- a/tools/lib/perf/tests/test-evsel.c > +++ b/tools/lib/perf/tests/test-evsel.c > @@ -130,6 +130,9 @@ static int test_stat_user_read(int event) > struct perf_event_attr attr = { > .type = PERF_TYPE_HARDWARE, > .config = event, > +#ifdef __aarch64__ > + .config1 = 0x2, /* Request user access */ > +#endif > }; > int err, i; > > @@ -150,7 +153,7 @@ static int test_stat_user_read(int event) > pc = perf_evsel__mmap_base(evsel, 0, 0); > __T("failed to get mmapped address", pc); > > -#if defined(__i386__) || defined(__x86_64__) > +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) > __T("userspace counter access not supported", pc->cap_user_rdpmc); > __T("userspace counter access not enabled", pc->index); > __T("userspace counter width not set", pc->pmc_width >= 32); > -- > 2.32.0 >
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