lib: sbi: Add PMU support

RISC-V SBI v0.3 specification defined a PMU extension to configure/start/stop
the hardware/firmware pmu events.

Implement PMU support in OpenSBI library. The implementation is agnostic of
event to counter mapping & mhpmevent value configuration. That means, it
expects platform hooks will be used to set up the mapping and provide
the mhpmevent value at runtime.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

3 files changed, 212 insertions, 1 deletions

diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h
index 559a33e..70a3bf7 100644
--- a/include/sbi/sbi_ecall_interface.h
+++ b/include/sbi/sbi_ecall_interface.h
@@ -28,6 +28,7 @@
 #define SBI_EXT_RFENCE				0x52464E43
 #define SBI_EXT_HSM				0x48534D
 #define SBI_EXT_SRST				0x53525354
+#define SBI_EXT_PMU				0x504D55
 
 /* SBI function IDs for BASE extension*/
 #define SBI_EXT_BASE_GET_SPEC_VERSION		0x0
@@ -91,6 +92,139 @@
 #define SBI_SRST_RESET_REASON_NONE	0x0
 #define SBI_SRST_RESET_REASON_SYSFAIL	0x1
 
+/* SBI function IDs for PMU extension */
+#define SBI_EXT_PMU_NUM_COUNTERS	0x0
+#define SBI_EXT_PMU_COUNTER_GET_INFO	0x1
+#define SBI_EXT_PMU_COUNTER_CFG_MATCH	0x2
+#define SBI_EXT_PMU_COUNTER_START	0x3
+#define SBI_EXT_PMU_COUNTER_STOP	0x4
+#define SBI_EXT_PMU_COUNTER_FW_READ	0x5
+
+/** General pmu event codes specified in SBI PMU extension */
+enum sbi_pmu_hw_generic_events_t {
+	SBI_PMU_HW_NO_EVENT			= 0,
+	SBI_PMU_HW_CPU_CYCLES			= 1,
+	SBI_PMU_HW_INSTRUCTIONS			= 2,
+	SBI_PMU_HW_CACHE_REFERENCES		= 3,
+	SBI_PMU_HW_CACHE_MISSES			= 4,
+	SBI_PMU_HW_BRANCH_INSTRUCTIONS		= 5,
+	SBI_PMU_HW_BRANCH_MISSES		= 6,
+	SBI_PMU_HW_BUS_CYCLES			= 7,
+	SBI_PMU_HW_STALLED_CYCLES_FRONTEND	= 8,
+	SBI_PMU_HW_STALLED_CYCLES_BACKEND	= 9,
+	SBI_PMU_HW_REF_CPU_CYCLES		= 10,
+
+	SBI_PMU_HW_GENERAL_MAX,
+};
+
+/**
+ * Generalized hardware cache events:
+ *
+ *       { L1-D, L1-I, LLC, ITLB, DTLB, BPU, NODE } x
+ *       { read, write, prefetch } x
+ *       { accesses, misses }
+ */
+enum sbi_pmu_hw_cache_id {
+	SBI_PMU_HW_CACHE_L1D		= 0,
+	SBI_PMU_HW_CACHE_L1I		= 1,
+	SBI_PMU_HW_CACHE_LL		= 2,
+	SBI_PMU_HW_CACHE_DTLB		= 3,
+	SBI_PMU_HW_CACHE_ITLB		= 4,
+	SBI_PMU_HW_CACHE_BPU		= 5,
+	SBI_PMU_HW_CACHE_NODE		= 6,
+
+	SBI_PMU_HW_CACHE_MAX,
+};
+
+enum sbi_pmu_hw_cache_op_id {
+	SBI_PMU_HW_CACHE_OP_READ	= 0,
+	SBI_PMU_HW_CACHE_OP_WRITE	= 1,
+	SBI_PMU_HW_CACHE_OP_PREFETCH	= 2,
+
+	SBI_PMU_HW_CACHE_OP_MAX,
+};
+
+enum sbi_pmu_hw_cache_op_result_id {
+	SBI_PMU_HW_CACHE_RESULT_ACCESS	= 0,
+	SBI_PMU_HW_CACHE_RESULT_MISS	= 1,
+
+	SBI_PMU_HW_CACHE_RESULT_MAX,
+};
+
+/**
+ * Special "firmware" events provided by the OpenSBI, even if the hardware
+ * does not support performance events. These events are encoded as a raw
+ * event type in Linux kernel perf framework.
+ */
+enum sbi_pmu_fw_event_code_id {
+	SBI_PMU_FW_MISALIGNED_LOAD	= 0,
+	SBI_PMU_FW_MISALIGNED_STORE	= 1,
+	SBI_PMU_FW_ACCESS_LOAD		= 2,
+	SBI_PMU_FW_ACCESS_STORE		= 3,
+	SBI_PMU_FW_ILLEGAL_INSN		= 4,
+	SBI_PMU_FW_SET_TIMER		= 5,
+	SBI_PMU_FW_IPI_SENT		= 6,
+	SBI_PMU_FW_IPI_RECVD		= 7,
+	SBI_PMU_FW_FENCE_I_SENT		= 8,
+	SBI_PMU_FW_FENCE_I_RECVD	= 9,
+	SBI_PMU_FW_SFENCE_VMA_SENT	= 10,
+	SBI_PMU_FW_SFENCE_VMA_RCVD	= 11,
+	SBI_PMU_FW_SFENCE_VMA_ASID_SENT	= 12,
+	SBI_PMU_FW_SFENCE_VMA_ASID_RCVD	= 13,
+
+	SBI_PMU_FW_HFENCE_GVMA_SENT	= 14,
+	SBI_PMU_FW_HFENCE_GVMA_RCVD	= 15,
+	SBI_PMU_FW_HFENCE_GVMA_VMID_SENT = 16,
+	SBI_PMU_FW_HFENCE_GVMA_VMID_RCVD = 17,
+
+	SBI_PMU_FW_HFENCE_VVMA_SENT	= 18,
+	SBI_PMU_FW_HFENCE_VVMA_RCVD	= 19,
+	SBI_PMU_FW_HFENCE_VVMA_ASID_SENT = 20,
+	SBI_PMU_FW_HFENCE_VVMA_ASID_RCVD = 21,
+	SBI_PMU_FW_MAX,
+};
+
+/** SBI PMU event idx type */
+enum sbi_pmu_event_type_id {
+	SBI_PMU_EVENT_TYPE_HW				= 0x0,
+	SBI_PMU_EVENT_TYPE_HW_CACHE			= 0x1,
+	SBI_PMU_EVENT_TYPE_HW_RAW			= 0x2,
+	SBI_PMU_EVENT_TYPE_FW				= 0xf,
+	SBI_PMU_EVENT_TYPE_MAX,
+};
+
+/** SBI PMU counter type */
+enum sbi_pmu_ctr_type {
+	SBI_PMU_CTR_TYPE_HW = 0,
+	SBI_PMU_CTR_TYPE_FW,
+};
+
+/* Helper macros to decode event idx */
+#define SBI_PMU_EVENT_IDX_OFFSET 20
+#define SBI_PMU_EVENT_IDX_MASK 0xFFFFF
+#define SBI_PMU_EVENT_IDX_CODE_MASK 0xFFFF
+#define SBI_PMU_EVENT_IDX_TYPE_MASK 0xF0000
+#define SBI_PMU_EVENT_RAW_IDX 0x20000
+
+#define SBI_PMU_EVENT_IDX_INVALID 0xFFFFFFFF
+
+/* Flags defined for config matching function */
+#define SBI_PMU_CFG_FLAG_SKIP_MATCH	(1 << 0)
+#define SBI_PMU_CFG_FLAG_CLEAR_VALUE	(1 << 1)
+#define SBI_PMU_CFG_FLAG_AUTO_START	(1 << 2)
+#define SBI_PMU_CFG_FLAG_SET_VUINH	(1 << 3)
+#define SBI_PMU_CFG_FLAG_SET_VSINH	(1 << 4)
+#define SBI_PMU_CFG_FLAG_SET_UINH	(1 << 5)
+#define SBI_PMU_CFG_FLAG_SET_SINH	(1 << 6)
+#define SBI_PMU_CFG_FLAG_SET_MINH	(1 << 7)
+
+/* Flags defined for counter start function */
+#define SBI_PMU_START_FLAG_SET_INIT_VALUE (1 << 0)
+
+/* Flags defined for counter stop function */
+#define SBI_PMU_STOP_FLAG_RESET (1 << 0)
+
+/* SBI base specification related macros */
 #define SBI_SPEC_VERSION_MAJOR_OFFSET		24
 #define SBI_SPEC_VERSION_MAJOR_MASK		0x7f
 #define SBI_SPEC_VERSION_MINOR_MASK		0xffffff
@@ -107,8 +241,10 @@
 #define SBI_ERR_DENIED				-4
 #define SBI_ERR_INVALID_ADDRESS			-5
 #define SBI_ERR_ALREADY_AVAILABLE		-6
+#define SBI_ERR_ALREADY_STARTED			-7
+#define SBI_ERR_ALREADY_STOPPED			-8
 
-#define SBI_LAST_ERR				SBI_ERR_ALREADY_AVAILABLE
+#define SBI_LAST_ERR				SBI_ERR_ALREADY_STOPPED
 
 /* clang-format on */
 
diff --git a/include/sbi/sbi_error.h b/include/sbi/sbi_error.h
index 3655d12..dd65e14 100644
--- a/include/sbi/sbi_error.h
+++ b/include/sbi/sbi_error.h
@@ -21,6 +21,8 @@
 #define SBI_EDENIED		SBI_ERR_DENIED
 #define SBI_EINVALID_ADDR	SBI_ERR_INVALID_ADDRESS
 #define SBI_EALREADY		SBI_ERR_ALREADY_AVAILABLE
+#define SBI_EALREADY_STARTED	SBI_ERR_ALREADY_STARTED
+#define SBI_EALREADY_STOPPED	SBI_ERR_ALREADY_STOPPED
 
 #define SBI_ENODEV		-1000
 #define SBI_ENOSYS		-1001
diff --git a/include/sbi/sbi_pmu.h b/include/sbi/sbi_pmu.h
new file mode 100644
index 0000000..b3010cc
--- /dev/null
+++ b/include/sbi/sbi_pmu.h
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#ifndef __SBI_PMU_H__
+#define __SBI_PMU_H__
+
+#include <sbi/sbi_types.h>
+#include <sbi/sbi_hartmask.h>
+#include <sbi/sbi_scratch.h>
+#include <sbi/sbi_ecall_interface.h>
+
+/* Event related macros */
+/* Maximum number of hardware events that can mapped by OpenSBI */
+#define SBI_PMU_HW_EVENT_MAX 64
+
+/* Maximum number of firmware events that can mapped by OpenSBI */
+#define SBI_PMU_FW_EVENT_MAX 32
+
+/* Counter related macros */
+#define SBI_PMU_FW_CTR_MAX 16
+#define SBI_PMU_HW_CTR_MAX 32
+#define SBI_PMU_CTR_MAX	   (SBI_PMU_HW_CTR_MAX + SBI_PMU_FW_CTR_MAX)
+
+/** Initialize PMU */
+int sbi_pmu_init(struct sbi_scratch *scratch, bool cold_boot);
+
+/** Reset PMU during hart exit */
+void sbi_pmu_exit(struct sbi_scratch *scratch);
+
+/**
+ * Add the hardware event to counter mapping information. This should be called
+ * from the platform code to update the mapping table.
+ * @param eidx_start Start of the event idx range for supported counters
+ * @param eidx_end   End of the event idx range for supported counters
+ * @param cmap       A bitmap representing counters supporting the event range
+ * @return 0 on success, error otherwise.
+ */
+int sbi_pmu_add_hw_event_counter_map(u32 eidx_start, u32 eidx_end, u32 cmap);
+
+/**
+ * Add the raw hardware event selector and supported counter information. This
+ * should be called from the platform code to update the mapping table.
+ * @param info  a pointer to the hardware event info
+ * @return 0 on success, error otherwise.
+ */
+
+int sbi_pmu_add_raw_event_counter_map(uint64_t select, u32 cmap);
+
+int sbi_pmu_ctr_read(uint32_t cidx, unsigned long *cval);
+
+int sbi_pmu_ctr_stop(unsigned long cidx_base, unsigned long cidx_mask,
+		     unsigned long flag);
+
+int sbi_pmu_ctr_start(unsigned long cidx_base, unsigned long cidx_mask,
+		      unsigned long flags, uint64_t ival);
+
+int sbi_pmu_ctr_get_info(uint32_t cidx, unsigned long *ctr_info);
+
+unsigned long sbi_pmu_num_ctr(void);
+
+int sbi_pmu_ctr_cfg_match(unsigned long cidx_base, unsigned long cidx_mask,
+			  unsigned long flags, unsigned long event_idx,
+			  uint64_t event_data);
+
+int sbi_pmu_ctr_incr_fw(enum sbi_pmu_fw_event_code_id fw_id);
+
+#endif