Unverified Commit 1537bf26 authored by Sergey Matyukevich's avatar Sergey Matyukevich Committed by Palmer Dabbelt
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perf: RISC-V: exclude invalid pmu counters from SBI calls 



SBI firmware may not provide information for some counters in response
to SBI_EXT_PMU_COUNTER_GET_INFO call. Exclude such counters from the
subsequent SBI requests. For this purpose use global mask to keep track
of fully specified counters.

Signed-off-by: default avatarSergey Matyukevich <sergey.matyukevich@syntacore.com>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220830155306.301714-3-geomatsi@gmail.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 82c75dca

drivers/perf/riscv_pmu_legacy.c

+2 −2
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 


#define RISCV_PMU_LEGACY_CYCLE		0

#define RISCV_PMU_LEGACY_INSTRET	1

#define RISCV_PMU_LEGACY_NUM_CTR	2



static bool pmu_init_done;
@@ -83,7 +82,8 @@ static void pmu_legacy_init(struct riscv_pmu *pmu) 
{

	pr_info("Legacy PMU implementation is available\n");



	pmu->num_counters = RISCV_PMU_LEGACY_NUM_CTR;

	pmu->cmask = BIT(RISCV_PMU_LEGACY_CYCLE) |

		BIT(RISCV_PMU_LEGACY_INSTRET);

	pmu->ctr_start = pmu_legacy_ctr_start;

	pmu->ctr_stop = NULL;

	pmu->event_map = pmu_legacy_event_map;

drivers/perf/riscv_pmu_sbi.c

+16 −11
Original line number Diff line number Diff line
@@ -271,7 +271,6 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) 
	struct sbiret ret;

	int idx;

	uint64_t cbase = 0;

	uint64_t cmask = GENMASK_ULL(rvpmu->num_counters - 1, 0);

	unsigned long cflags = 0;



	if (event->attr.exclude_kernel)
@@ -281,11 +280,12 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) 


	/* retrieve the available counter index */

#if defined(CONFIG_32BIT)

	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask,

			cflags, hwc->event_base, hwc->config, hwc->config >> 32);

	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,

			rvpmu->cmask, cflags, hwc->event_base, hwc->config,

			hwc->config >> 32);

#else

	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask,

			cflags, hwc->event_base, hwc->config, 0);

	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,

			rvpmu->cmask, cflags, hwc->event_base, hwc->config, 0);

#endif

	if (ret.error) {

		pr_debug("Not able to find a counter for event %lx config %llx\n",
@@ -294,7 +294,7 @@ static int pmu_sbi_ctr_get_idx(struct perf_event *event) 
	}



	idx = ret.value;

	if (idx >= rvpmu->num_counters || !pmu_ctr_list[idx].value)

	if (!test_bit(idx, &rvpmu->cmask) || !pmu_ctr_list[idx].value)

		return -ENOENT;



	/* Additional sanity check for the counter id */
@@ -463,7 +463,7 @@ static int pmu_sbi_find_num_ctrs(void) 
		return sbi_err_map_linux_errno(ret.error);

}



static int pmu_sbi_get_ctrinfo(int nctr)

static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask)

{

	struct sbiret ret;

	int i, num_hw_ctr = 0, num_fw_ctr = 0;
@@ -478,6 +478,9 @@ static int pmu_sbi_get_ctrinfo(int nctr) 
		if (ret.error)

			/* The logical counter ids are not expected to be contiguous */

			continue;



		*mask |= BIT(i);



		cinfo.value = ret.value;

		if (cinfo.type == SBI_PMU_CTR_TYPE_FW)

			num_fw_ctr++;
@@ -498,7 +501,7 @@ static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu) 
	 * which may include counters that are not enabled yet.

	 */

	sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,

		  0, GENMASK_ULL(pmu->num_counters - 1, 0), 0, 0, 0, 0);

		  0, pmu->cmask, 0, 0, 0, 0);

}



static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)
@@ -788,8 +791,9 @@ static void riscv_pmu_destroy(struct riscv_pmu *pmu) 
static int pmu_sbi_device_probe(struct platform_device *pdev)

{

	struct riscv_pmu *pmu = NULL;

	int num_counters;

	unsigned long cmask = 0;

	int ret = -ENODEV;

	int num_counters;



	pr_info("SBI PMU extension is available\n");

	pmu = riscv_pmu_alloc();
@@ -803,7 +807,7 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) 
	}



	/* cache all the information about counters now */

	if (pmu_sbi_get_ctrinfo(num_counters))

	if (pmu_sbi_get_ctrinfo(num_counters, &cmask))

		goto out_free;



	ret = pmu_sbi_setup_irqs(pmu, pdev);
@@ -812,8 +816,9 @@ static int pmu_sbi_device_probe(struct platform_device *pdev) 
		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;

	}



	pmu->pmu.attr_groups = riscv_pmu_attr_groups;

	pmu->num_counters = num_counters;

	pmu->cmask = cmask;

	pmu->ctr_start = pmu_sbi_ctr_start;

	pmu->ctr_stop = pmu_sbi_ctr_stop;

	pmu->event_map = pmu_sbi_event_map;

include/linux/perf/riscv_pmu.h

+1 −1
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ struct riscv_pmu { 


	irqreturn_t	(*handle_irq)(int irq_num, void *dev);



	int		num_counters;

	unsigned long	cmask;

	u64		(*ctr_read)(struct perf_event *event);

	int		(*ctr_get_idx)(struct perf_event *event);

	int		(*ctr_get_width)(int idx);