| Message ID | 20230703124647.215952-10-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: Allow userspace to directly access perf counters | expand |
On Mon, Jul 3, 2023 at 5:56 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > riscv now supports mmaping hardware counters so add what's needed to > take advantage of that in libperf. > > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > --- > tools/lib/perf/mmap.c | 65 +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 65 insertions(+) > > diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c > index 0d1634cedf44..378a163f0554 100644 > --- a/tools/lib/perf/mmap.c > +++ b/tools/lib/perf/mmap.c > @@ -392,6 +392,71 @@ static u64 read_perf_counter(unsigned int counter) > > static u64 read_timestamp(void) { return read_sysreg(cntvct_el0); } > > +#elif __riscv_xlen == 64 > + > +/* TODO: implement rv32 support */ > + > +#define CSR_CYCLE 0xc00 > +#define CSR_TIME 0xc01 > + > +#define csr_read(csr) \ > +({ \ > + register unsigned long __v; \ > + __asm__ __volatile__ ("csrr %0, " #csr \ > + : "=r" (__v) : \ > + : "memory"); \ > + __v; \ > +}) > + > +static unsigned long csr_read_num(int csr_num) > +{ > +#define switchcase_csr_read(__csr_num, __val) {\ > + case __csr_num: \ > + __val = csr_read(__csr_num); \ > + break; } > +#define switchcase_csr_read_2(__csr_num, __val) {\ > + switchcase_csr_read(__csr_num + 0, __val) \ > + switchcase_csr_read(__csr_num + 1, __val)} > +#define switchcase_csr_read_4(__csr_num, __val) {\ > + switchcase_csr_read_2(__csr_num + 0, __val) \ > + switchcase_csr_read_2(__csr_num + 2, __val)} > +#define switchcase_csr_read_8(__csr_num, __val) {\ > + switchcase_csr_read_4(__csr_num + 0, __val) \ > + switchcase_csr_read_4(__csr_num + 4, __val)} > +#define switchcase_csr_read_16(__csr_num, __val) {\ > + switchcase_csr_read_8(__csr_num + 0, __val) \ > + switchcase_csr_read_8(__csr_num + 8, __val)} > +#define switchcase_csr_read_32(__csr_num, __val) {\ > + switchcase_csr_read_16(__csr_num + 0, __val) \ > + switchcase_csr_read_16(__csr_num + 16, __val)} > + > + unsigned long ret = 0; > + > + switch (csr_num) { > + switchcase_csr_read_32(CSR_CYCLE, ret) > + default: > + break; > + } > + > + return ret; > +#undef switchcase_csr_read_32 > +#undef switchcase_csr_read_16 > +#undef switchcase_csr_read_8 > +#undef switchcase_csr_read_4 > +#undef switchcase_csr_read_2 > +#undef switchcase_csr_read > +} > + > +static u64 read_perf_counter(unsigned int counter) > +{ > + return csr_read_num(CSR_CYCLE + counter); > +} > + > +static u64 read_timestamp(void) > +{ > + return csr_read_num(CSR_TIME); > +} > + > #else > static u64 read_perf_counter(unsigned int counter __maybe_unused) { return 0; } > static u64 read_timestamp(void) { return 0; } > -- > 2.39.2 > Reviewed-by: Atish Patra <atishp@rivosinc.com>
diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c index 0d1634cedf44..378a163f0554 100644 --- a/tools/lib/perf/mmap.c +++ b/tools/lib/perf/mmap.c @@ -392,6 +392,71 @@ static u64 read_perf_counter(unsigned int counter) static u64 read_timestamp(void) { return read_sysreg(cntvct_el0); } +#elif __riscv_xlen == 64 + +/* TODO: implement rv32 support */ + +#define CSR_CYCLE 0xc00 +#define CSR_TIME 0xc01 + +#define csr_read(csr) \ +({ \ + register unsigned long __v; \ + __asm__ __volatile__ ("csrr %0, " #csr \ + : "=r" (__v) : \ + : "memory"); \ + __v; \ +}) + +static unsigned long csr_read_num(int csr_num) +{ +#define switchcase_csr_read(__csr_num, __val) {\ + case __csr_num: \ + __val = csr_read(__csr_num); \ + break; } +#define switchcase_csr_read_2(__csr_num, __val) {\ + switchcase_csr_read(__csr_num + 0, __val) \ + switchcase_csr_read(__csr_num + 1, __val)} +#define switchcase_csr_read_4(__csr_num, __val) {\ + switchcase_csr_read_2(__csr_num + 0, __val) \ + switchcase_csr_read_2(__csr_num + 2, __val)} +#define switchcase_csr_read_8(__csr_num, __val) {\ + switchcase_csr_read_4(__csr_num + 0, __val) \ + switchcase_csr_read_4(__csr_num + 4, __val)} +#define switchcase_csr_read_16(__csr_num, __val) {\ + switchcase_csr_read_8(__csr_num + 0, __val) \ + switchcase_csr_read_8(__csr_num + 8, __val)} +#define switchcase_csr_read_32(__csr_num, __val) {\ + switchcase_csr_read_16(__csr_num + 0, __val) \ + switchcase_csr_read_16(__csr_num + 16, __val)} + + unsigned long ret = 0; + + switch (csr_num) { + switchcase_csr_read_32(CSR_CYCLE, ret) + default: + break; + } + + return ret; +#undef switchcase_csr_read_32 +#undef switchcase_csr_read_16 +#undef switchcase_csr_read_8 +#undef switchcase_csr_read_4 +#undef switchcase_csr_read_2 +#undef switchcase_csr_read +} + +static u64 read_perf_counter(unsigned int counter) +{ + return csr_read_num(CSR_CYCLE + counter); +} + +static u64 read_timestamp(void) +{ + return csr_read_num(CSR_TIME); +} + #else static u64 read_perf_counter(unsigned int counter __maybe_unused) { return 0; } static u64 read_timestamp(void) { return 0; }