[PATCH v8 07/10] perf: RISC-V: Introduce Andes PMU to support perf event sampling
From: Yu Chien Peter Lin
Date: Mon Jan 29 2024 - 04:29:36 EST
Assign riscv_pmu_irq_num the value of (256 + 18) for the custome PMU
and add SSCOUNTOVF and SIP alternatives to ALT_SBI_PMU_OVERFLOW()
and ALT_SBI_PMU_OVF_CLEAR_PENDING() macros, respectively.
To make use of Andes PMU extension, "xandespmu" needs to be appended
to the riscv,isa-extensions for each cpu node in device-tree, and
make sure CONFIG_ANDES_CUSTOM_PMU is enabled.
Signed-off-by: Yu Chien Peter Lin <peterlin@xxxxxxxxxxxxx>
Reviewed-by: Charles Ci-Jyun Wu <dminus@xxxxxxxxxxxxx>
Reviewed-by: Leo Yu-Chi Liang <ycliang@xxxxxxxxxxxxx>
Co-developed-by: Locus Wei-Han Chen <locus84@xxxxxxxxxxxxx>
Signed-off-by: Locus Wei-Han Chen <locus84@xxxxxxxxxxxxx>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
Changes v1 -> v2:
- New patch
Changes v2 -> v3:
- Reordered list in riscv_isa_ext[]
- Removed mvendorid check in pmu_sbi_setup_irqs()
Changes v3 -> v4:
- No change
Changes v4 -> v5:
- Let ANDES_CUSTOM_PMU depend on ARCH_RENESAS
- Include Prabhakar's Reviewed/Tested-by
Changes v5 -> v6:
- No change
Changes v6 -> v7:
- No change
Changes v7 -> v8:
- No change
---
arch/riscv/include/asm/errata_list.h | 9 -------
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/kernel/cpufeature.c | 1 +
drivers/perf/Kconfig | 14 +++++++++++
drivers/perf/riscv_pmu_sbi.c | 35 +++++++++++++++++++++++++---
5 files changed, 48 insertions(+), 12 deletions(-)
diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
index 96025eec5631..1f2dbfb8a8bf 100644
--- a/arch/riscv/include/asm/errata_list.h
+++ b/arch/riscv/include/asm/errata_list.h
@@ -112,15 +112,6 @@ asm volatile(ALTERNATIVE( \
#define THEAD_C9XX_RV_IRQ_PMU 17
#define THEAD_C9XX_CSR_SCOUNTEROF 0x5c5
-#define ALT_SBI_PMU_OVERFLOW(__ovl) \
-asm volatile(ALTERNATIVE( \
- "csrr %0, " __stringify(CSR_SSCOUNTOVF), \
- "csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \
- THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \
- CONFIG_ERRATA_THEAD_PMU) \
- : "=r" (__ovl) : \
- : "memory")
-
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 5340f818746b..bae7eac76c18 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -80,6 +80,7 @@
#define RISCV_ISA_EXT_ZFA 71
#define RISCV_ISA_EXT_ZTSO 72
#define RISCV_ISA_EXT_ZACAS 73
+#define RISCV_ISA_EXT_XANDESPMU 74
#define RISCV_ISA_EXT_MAX 128
#define RISCV_ISA_EXT_INVALID U32_MAX
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 89920f84d0a3..0c7688fa8376 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -307,6 +307,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
__RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
+ __RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_EXT_XANDESPMU),
};
const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index ec6e0d9194a1..564e813d8c69 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -86,6 +86,20 @@ config RISCV_PMU_SBI
full perf feature support i.e. counter overflow, privilege mode
filtering, counter configuration.
+config ANDES_CUSTOM_PMU
+ bool "Andes custom PMU support"
+ depends on ARCH_RENESAS && RISCV_ALTERNATIVE && RISCV_PMU_SBI
+ default y
+ help
+ The Andes cores implement the PMU overflow extension very
+ similar to the standard Sscofpmf and Smcntrpmf extension.
+
+ This will patch the overflow and pending CSRs and handle the
+ non-standard behaviour via the regular SBI PMU driver and
+ interface.
+
+ If you don't know what to do here, say "Y".
+
config ARM_PMU_ACPI
depends on ARM_PMU && ACPI
def_bool y
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 2edbc37abadf..bbd6fe021b3a 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -19,11 +19,33 @@
#include <linux/of.h>
#include <linux/cpu_pm.h>
#include <linux/sched/clock.h>
+#include <linux/soc/andes/irq.h>
#include <asm/errata_list.h>
#include <asm/sbi.h>
#include <asm/cpufeature.h>
+#define ALT_SBI_PMU_OVERFLOW(__ovl) \
+asm volatile(ALTERNATIVE_2( \
+ "csrr %0, " __stringify(CSR_SSCOUNTOVF), \
+ "csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \
+ THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \
+ CONFIG_ERRATA_THEAD_PMU, \
+ "csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF), \
+ 0, RISCV_ISA_EXT_XANDESPMU, \
+ CONFIG_ANDES_CUSTOM_PMU) \
+ : "=r" (__ovl) : \
+ : "memory")
+
+#define ALT_SBI_PMU_OVF_CLEAR_PENDING(__irq_mask) \
+asm volatile(ALTERNATIVE( \
+ "csrc " __stringify(CSR_IP) ", %0\n\t", \
+ "csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t", \
+ 0, RISCV_ISA_EXT_XANDESPMU, \
+ CONFIG_ANDES_CUSTOM_PMU) \
+ : : "r"(__irq_mask) \
+ : "memory")
+
#define SYSCTL_NO_USER_ACCESS 0
#define SYSCTL_USER_ACCESS 1
#define SYSCTL_LEGACY 2
@@ -61,6 +83,7 @@ static int sysctl_perf_user_access __read_mostly = SYSCTL_USER_ACCESS;
static union sbi_pmu_ctr_info *pmu_ctr_list;
static bool riscv_pmu_use_irq;
static unsigned int riscv_pmu_irq_num;
+static unsigned int riscv_pmu_irq_mask;
static unsigned int riscv_pmu_irq;
/* Cache the available counters in a bitmask */
@@ -694,7 +717,7 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
event = cpu_hw_evt->events[fidx];
if (!event) {
- csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
+ ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
return IRQ_NONE;
}
@@ -708,7 +731,7 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
* Overflow interrupt pending bit should only be cleared after stopping
* all the counters to avoid any race condition.
*/
- csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
+ ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
/* No overflow bit is set */
if (!overflow)
@@ -780,7 +803,7 @@ static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
if (riscv_pmu_use_irq) {
cpu_hw_evt->irq = riscv_pmu_irq;
- csr_clear(CSR_IP, BIT(riscv_pmu_irq_num));
+ ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE);
}
@@ -814,8 +837,14 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
riscv_cached_mimpid(0) == 0) {
riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
riscv_pmu_use_irq = true;
+ } else if (riscv_isa_extension_available(NULL, XANDESPMU) &&
+ IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
+ riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
+ riscv_pmu_use_irq = true;
}
+ riscv_pmu_irq_mask = BIT(riscv_pmu_irq_num % BITS_PER_LONG);
+
if (!riscv_pmu_use_irq)
return -EOPNOTSUPP;
--
2.34.1