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drivers/perf: riscv: Implement PMU event info function

With the new SBI PMU event info function, we can query the availability of the all standard SBI PMU events at boot time with a single ecall. This improves the bootime by avoiding making an SBI call for each standard PMU event. Since this function is defined only in SBI v3.0, invoke this only if the underlying SBI implementation is v3.0 or higher.

Atish Patra committed 1 year ago

Commit adffbd01 parent 190b7412 files · +78 −0Browse files

Unified · Split

2 files
  1. arch/riscv/include/asm/sbi.h +9 −0
  2. drivers/perf/riscv_pmu_sbi.c +69 −0
arch/riscv/include/asm/sbi.h+9−0
@@ -136,6 +136,7 @@ enum sbi_ext_pmu_fid { · 135 unmodified lines
136136 SBI_EXT_PMU_COUNTER_FW_READ,
137137 SBI_EXT_PMU_COUNTER_FW_READ_HI,
138138 SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
139+ SBI_EXT_PMU_EVENT_GET_INFO,
139140 };
140141
141142 union sbi_pmu_ctr_info {
@@ -159,6 +160,14 @@ struct riscv_pmu_snapshot_data { · 17 unmodified lines
159160 u64 reserved[447];
160161 };
161162
163+struct riscv_pmu_event_info {
164+ u32 event_idx;
165+ u32 output;
166+ u64 event_data;
167+};
168+
169+#define RISCV_PMU_EVENT_INFO_OUTPUT_MASK 0x01
170+
162171 #define RISCV_PMU_RAW_EVENT_MASK GENMASK_ULL(47, 0)
163172 #define RISCV_PMU_PLAT_FW_EVENT_MASK GENMASK_ULL(61, 0)
164173 /* SBI v3.0 allows extended hpmeventX width value */
drivers/perf/riscv_pmu_sbi.c+69−0
@@ -299,6 +299,66 @@ static struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX] · 298 unmodified lines
299299 },
300300 };
301301
302+static int pmu_sbi_check_event_info(void)
303+{
304+ int num_events = ARRAY_SIZE(pmu_hw_event_map) + PERF_COUNT_HW_CACHE_MAX *
305+ PERF_COUNT_HW_CACHE_OP_MAX * PERF_COUNT_HW_CACHE_RESULT_MAX;
306+ struct riscv_pmu_event_info *event_info_shmem;
307+ phys_addr_t base_addr;
308+ int i, j, k, result = 0, count = 0;
309+ struct sbiret ret;
310+
311+ event_info_shmem = kcalloc(num_events, sizeof(*event_info_shmem), GFP_KERNEL);
312+ if (!event_info_shmem)
313+ return -ENOMEM;
314+
315+ for (i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++)
316+ event_info_shmem[count++].event_idx = pmu_hw_event_map[i].event_idx;
317+
318+ for (i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++) {
319+ for (j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++) {
320+ for (k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++)
321+ event_info_shmem[count++].event_idx =
322+ pmu_cache_event_map[i][j][k].event_idx;
323+ }
324+ }
325+
326+ base_addr = __pa(event_info_shmem);
327+ if (IS_ENABLED(CONFIG_32BIT))
328+ ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_EVENT_GET_INFO, lower_32_bits(base_addr),
329+ upper_32_bits(base_addr), count, 0, 0, 0);
330+ else
331+ ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_EVENT_GET_INFO, base_addr, 0,
332+ count, 0, 0, 0);
333+ if (ret.error) {
334+ result = -EOPNOTSUPP;
335+ goto free_mem;
336+ }
337+
338+ for (i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++) {
339+ if (!(event_info_shmem[i].output & RISCV_PMU_EVENT_INFO_OUTPUT_MASK))
340+ pmu_hw_event_map[i].event_idx = -ENOENT;
341+ }
342+
343+ count = ARRAY_SIZE(pmu_hw_event_map);
344+
345+ for (i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++) {
346+ for (j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++) {
347+ for (k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++) {
348+ if (!(event_info_shmem[count].output &
349+ RISCV_PMU_EVENT_INFO_OUTPUT_MASK))
350+ pmu_cache_event_map[i][j][k].event_idx = -ENOENT;
351+ count++;
352+ }
353+ }
354+ }
355+
356+free_mem:
357+ kfree(event_info_shmem);
358+
359+ return result;
360+}
361+
302362 static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata)
303363 {
304364 struct sbiret ret;
@@ -316,6 +376,15 @@ static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata) · 11 unmodified lines
316376
317377 static void pmu_sbi_check_std_events(struct work_struct *work)
318378 {
379+ int ret;
380+
381+ if (sbi_v3_available) {
382+ ret = pmu_sbi_check_event_info();
383+ if (ret)
384+ pr_err("pmu_sbi_check_event_info failed with error %d\n", ret);
385+ return;
386+ }
387+
319388 for (int i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++)
320389 pmu_sbi_check_event(&pmu_hw_event_map[i]);
321390

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