Unverified Commit 60bd5011 authored by Alexandre Ghiti's avatar Alexandre Ghiti Committed by Palmer Dabbelt
Browse files

tools: lib: perf: Implement riscv mmap support 



riscv now supports mmaping hardware counters so add what's needed to
take advantage of that in libperf.

Signed-off-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Reviewed-by: default avatarIan Rogers <irogers@google.com>
parent 57972127

tools/lib/perf/mmap.c

+66 −0
Original line number Diff line number Diff line
@@ -392,6 +392,72 @@ static u64 read_perf_counter(unsigned int counter) 


static u64 read_timestamp(void) { return read_sysreg(cntvct_el0); }



/* __riscv_xlen contains the witdh of the native base integer, here 64-bit */

#elif defined(__riscv) && __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, %1"		\

		 : "=r" (__v)					\

		 : "i" (csr) : );				\

		 __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; }