perf: RISC-V: Add support for SBI PMU and Sscofpmf

This series improves perf support for RISC-V based system using SBI PMU
and Sscofpmf extensions, by adding a new generic RISC-V perf framework
along with a pair of drivers: one that usese the new
performance-monitoring extensions and one that keeps support for the
existing systems that only have the legacy counters.

Tested-by: Nikita Shubin <n.shubin@yadro.com>

* palmer/riscv-pmu:
  MAINTAINERS: Add entry for RISC-V PMU drivers
  Documentation: riscv: Remove the old documentation
  RISC-V: Add sscofpmf extension support
  RISC-V: Add perf platform driver based on SBI PMU extension
  RISC-V: Add RISC-V SBI PMU extension definitions
  RISC-V: Add a simple platform driver for RISC-V legacy perf
  RISC-V: Add a perf core library for pmu drivers
  RISC-V: Add CSR encodings for all HPMCOUNTERS
  RISC-V: Remove the current perf implementation

18 files changed, 1538 insertions, 827 deletions

diff --git a/Documentation/riscv/pmu.rst b/Documentation/riscv/pmu.rst
deleted file mode 100644
index acb216b99c26..000000000000
--- a/Documentation/riscv/pmu.rst
+++ /dev/null
@@ -1,255 +0,0 @@
-===================================
-Supporting PMUs on RISC-V platforms
-===================================
-
-Alan Kao <alankao@andestech.com>, Mar 2018
-
-Introduction
-------------
-
-As of this writing, perf_event-related features mentioned in The RISC-V ISA
-Privileged Version 1.10 are as follows:
-(please check the manual for more details)
-
-* [m|s]counteren
-* mcycle[h], cycle[h]
-* minstret[h], instret[h]
-* mhpeventx, mhpcounterx[h]
-
-With such function set only, porting perf would require a lot of work, due to
-the lack of the following general architectural performance monitoring features:
-
-* Enabling/Disabling counters
-  Counters are just free-running all the time in our case.
-* Interrupt caused by counter overflow
-  No such feature in the spec.
-* Interrupt indicator
-  It is not possible to have many interrupt ports for all counters, so an
-  interrupt indicator is required for software to tell which counter has
-  just overflowed.
-* Writing to counters
-  There will be an SBI to support this since the kernel cannot modify the
-  counters [1].  Alternatively, some vendor considers to implement
-  hardware-extension for M-S-U model machines to write counters directly.
-
-This document aims to provide developers a quick guide on supporting their
-PMUs in the kernel.  The following sections briefly explain perf' mechanism
-and todos.
-
-You may check previous discussions here [1][2].  Also, it might be helpful
-to check the appendix for related kernel structures.
-
-
-1. Initialization
------------------
-
-*riscv_pmu* is a global pointer of type *struct riscv_pmu*, which contains
-various methods according to perf's internal convention and PMU-specific
-parameters.  One should declare such instance to represent the PMU.  By default,
-*riscv_pmu* points to a constant structure *riscv_base_pmu*, which has very
-basic support to a baseline QEMU model.
-
-Then he/she can either assign the instance's pointer to *riscv_pmu* so that
-the minimal and already-implemented logic can be leveraged, or invent his/her
-own *riscv_init_platform_pmu* implementation.
-
-In other words, existing sources of *riscv_base_pmu* merely provide a
-reference implementation.  Developers can flexibly decide how many parts they
-can leverage, and in the most extreme case, they can customize every function
-according to their needs.
-
-
-2. Event Initialization
------------------------
-
-When a user launches a perf command to monitor some events, it is first
-interpreted by the userspace perf tool into multiple *perf_event_open*
-system calls, and then each of them calls to the body of *event_init*
-member function that was assigned in the previous step.  In *riscv_base_pmu*'s
-case, it is *riscv_event_init*.
-
-The main purpose of this function is to translate the event provided by user
-into bitmap, so that HW-related control registers or counters can directly be
-manipulated.  The translation is based on the mappings and methods provided in
-*riscv_pmu*.
-
-Note that some features can be done in this stage as well:
-
-(1) interrupt setting, which is stated in the next section;
-(2) privilege level setting (user space only, kernel space only, both);
-(3) destructor setting.  Normally it is sufficient to apply *riscv_destroy_event*;
-(4) tweaks for non-sampling events, which will be utilized by functions such as
-    *perf_adjust_period*, usually something like the follows::
-
-      if (!is_sampling_event(event)) {
-              hwc->sample_period = x86_pmu.max_period;
-              hwc->last_period = hwc->sample_period;
-              local64_set(&hwc->period_left, hwc->sample_period);
-      }
-
-In the case of *riscv_base_pmu*, only (3) is provided for now.
-
-
-3. Interrupt
-------------
-
-3.1. Interrupt Initialization
-
-This often occurs at the beginning of the *event_init* method. In common
-practice, this should be a code segment like::
-
-  int x86_reserve_hardware(void)
-  {
-        int err = 0;
-
-        if (!atomic_inc_not_zero(&pmc_refcount)) {
-                mutex_lock(&pmc_reserve_mutex);
-                if (atomic_read(&pmc_refcount) == 0) {
-                        if (!reserve_pmc_hardware())
-                                err = -EBUSY;
-                        else
-                                reserve_ds_buffers();
-                }
-                if (!err)
-                        atomic_inc(&pmc_refcount);
-                mutex_unlock(&pmc_reserve_mutex);
-        }
-
-        return err;
-  }
-
-And the magic is in *reserve_pmc_hardware*, which usually does atomic
-operations to make implemented IRQ accessible from some global function pointer.
-*release_pmc_hardware* serves the opposite purpose, and it is used in event
-destructors mentioned in previous section.
-
-(Note: From the implementations in all the architectures, the *reserve/release*
-pair are always IRQ settings, so the *pmc_hardware* seems somehow misleading.
-It does NOT deal with the binding between an event and a physical counter,
-which will be introduced in the next section.)
-
-3.2. IRQ Structure
-
-Basically, a IRQ runs the following pseudo code::
-
-  for each hardware counter that triggered this overflow
-
-      get the event of this counter
-
-      // following two steps are defined as *read()*,
-      // check the section Reading/Writing Counters for details.
-      count the delta value since previous interrupt
-      update the event->count (# event occurs) by adding delta, and
-                 event->hw.period_left by subtracting delta
-
-      if the event overflows
-          sample data
-          set the counter appropriately for the next overflow
-
-          if the event overflows again
-              too frequently, throttle this event
-          fi
-      fi
-
-  end for
-
-However as of this writing, none of the RISC-V implementations have designed an
-interrupt for perf, so the details are to be completed in the future.
-
-4. Reading/Writing Counters
----------------------------
-
-They seem symmetric but perf treats them quite differently.  For reading, there
-is a *read* interface in *struct pmu*, but it serves more than just reading.
-According to the context, the *read* function not only reads the content of the
-counter (event->count), but also updates the left period to the next interrupt
-(event->hw.period_left).
-
-But the core of perf does not need direct write to counters.  Writing counters
-is hidden behind the abstraction of 1) *pmu->start*, literally start counting so one
-has to set the counter to a good value for the next interrupt; 2) inside the IRQ
-it should set the counter to the same resonable value.
-
-Reading is not a problem in RISC-V but writing would need some effort, since
-counters are not allowed to be written by S-mode.
-
-
-5. add()/del()/start()/stop()
------------------------------
-
-Basic idea: add()/del() adds/deletes events to/from a PMU, and start()/stop()
-starts/stop the counter of some event in the PMU.  All of them take the same
-arguments: *struct perf_event *event* and *int flag*.
-
-Consider perf as a state machine, then you will find that these functions serve
-as the state transition process between those states.
-Three states (event->hw.state) are defined:
-
-* PERF_HES_STOPPED:	the counter is stopped
-* PERF_HES_UPTODATE:	the event->count is up-to-date
-* PERF_HES_ARCH:	arch-dependent usage ... we don't need this for now
-
-A normal flow of these state transitions are as follows:
-
-* A user launches a perf event, resulting in calling to *event_init*.
-* When being context-switched in, *add* is called by the perf core, with a flag
-  PERF_EF_START, which means that the event should be started after it is added.
-  At this stage, a general event is bound to a physical counter, if any.
-  The state changes to PERF_HES_STOPPED and PERF_HES_UPTODATE, because it is now
-  stopped, and the (software) event count does not need updating.
-
-  - *start* is then called, and the counter is enabled.
-    With flag PERF_EF_RELOAD, it writes an appropriate value to the counter (check
-    previous section for detail).
-    Nothing is written if the flag does not contain PERF_EF_RELOAD.
-    The state now is reset to none, because it is neither stopped nor updated
-    (the counting already started)
-
-* When being context-switched out, *del* is called.  It then checks out all the
-  events in the PMU and calls *stop* to update their counts.
-
-  - *stop* is called by *del*
-    and the perf core with flag PERF_EF_UPDATE, and it often shares the same
-    subroutine as *read* with the same logic.
-    The state changes to PERF_HES_STOPPED and PERF_HES_UPTODATE, again.
-
-  - Life cycle of these two pairs: *add* and *del* are called repeatedly as
-    tasks switch in-and-out; *start* and *stop* is also called when the perf core
-    needs a quick stop-and-start, for instance, when the interrupt period is being
-    adjusted.
-
-Current implementation is sufficient for now and can be easily extended to
-features in the future.
-
-A. Related Structures
----------------------
-
-* struct pmu: include/linux/perf_event.h
-* struct riscv_pmu: arch/riscv/include/asm/perf_event.h
-
-  Both structures are designed to be read-only.
-
-  *struct pmu* defines some function pointer interfaces, and most of them take
-  *struct perf_event* as a main argument, dealing with perf events according to
-  perf's internal state machine (check kernel/events/core.c for details).
-
-  *struct riscv_pmu* defines PMU-specific parameters.  The naming follows the
-  convention of all other architectures.
-
-* struct perf_event: include/linux/perf_event.h
-* struct hw_perf_event
-
-  The generic structure that represents perf events, and the hardware-related
-  details.
-
-* struct riscv_hw_events: arch/riscv/include/asm/perf_event.h
-
-  The structure that holds the status of events, has two fixed members:
-  the number of events and the array of the events.
-
-References
-----------
-
-[1] https://github.com/riscv/riscv-linux/pull/124
-
-[2] https://groups.google.com/a/groups.riscv.org/forum/#!topic/sw-dev/f19TmCNP6yA
diff --git a/MAINTAINERS b/MAINTAINERS
index 779a550dc95b..e4c3f7507665 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16561,6 +16561,15 @@ S:	Maintained
 F:	drivers/mtd/nand/raw/r852.c
 F:	drivers/mtd/nand/raw/r852.h
 
+RISC-V PMU DRIVERS
+M:	Atish Patra <atishp@atishpatra.org>
+R:	Anup Patel <anup@brainfault.org>
+L:	linux-riscv@lists.infradead.org
+S:	Supported
+F:	drivers/perf/riscv_pmu.c
+F:	drivers/perf/riscv_pmu_legacy.c
+F:	drivers/perf/riscv_pmu_sbi.c
+
 RISC-V ARCHITECTURE
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 M:	Palmer Dabbelt <palmer@dabbelt.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 81682a152800..339ba6f6580d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -333,19 +333,6 @@ config RISCV_ISA_C
 
 	   If you don't know what to do here, say Y.
 
-menu "supported PMU type"
-	depends on PERF_EVENTS
-
-config RISCV_BASE_PMU
-	bool "Base Performance Monitoring Unit"
-	def_bool y
-	help
-	  A base PMU that serves as a reference implementation and has limited
-	  feature of perf.  It can run on any RISC-V machines so serves as the
-	  fallback, but this option can also be disable to reduce kernel size.
-
-endmenu
-
 config FPU
 	bool "FPU support"
 	default y
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 299abdef0cd6..e935f27b10fd 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -66,6 +66,7 @@
 #define IRQ_S_EXT		9
 #define IRQ_VS_EXT		10
 #define IRQ_M_EXT		11
+#define IRQ_PMU_OVF		13
 
 /* Exception causes */
 #define EXC_INST_MISALIGNED	0
@@ -151,9 +152,69 @@
 #define CSR_CYCLE		0xc00
 #define CSR_TIME		0xc01
 #define CSR_INSTRET		0xc02
+#define CSR_HPMCOUNTER3		0xc03
+#define CSR_HPMCOUNTER4		0xc04
+#define CSR_HPMCOUNTER5		0xc05
+#define CSR_HPMCOUNTER6		0xc06
+#define CSR_HPMCOUNTER7		0xc07
+#define CSR_HPMCOUNTER8		0xc08
+#define CSR_HPMCOUNTER9		0xc09
+#define CSR_HPMCOUNTER10	0xc0a
+#define CSR_HPMCOUNTER11	0xc0b
+#define CSR_HPMCOUNTER12	0xc0c
+#define CSR_HPMCOUNTER13	0xc0d
+#define CSR_HPMCOUNTER14	0xc0e
+#define CSR_HPMCOUNTER15	0xc0f
+#define CSR_HPMCOUNTER16	0xc10
+#define CSR_HPMCOUNTER17	0xc11
+#define CSR_HPMCOUNTER18	0xc12
+#define CSR_HPMCOUNTER19	0xc13
+#define CSR_HPMCOUNTER20	0xc14
+#define CSR_HPMCOUNTER21	0xc15
+#define CSR_HPMCOUNTER22	0xc16
+#define CSR_HPMCOUNTER23	0xc17
+#define CSR_HPMCOUNTER24	0xc18
+#define CSR_HPMCOUNTER25	0xc19
+#define CSR_HPMCOUNTER26	0xc1a
+#define CSR_HPMCOUNTER27	0xc1b
+#define CSR_HPMCOUNTER28	0xc1c
+#define CSR_HPMCOUNTER29	0xc1d
+#define CSR_HPMCOUNTER30	0xc1e
+#define CSR_HPMCOUNTER31	0xc1f
 #define CSR_CYCLEH		0xc80
 #define CSR_TIMEH		0xc81
 #define CSR_INSTRETH		0xc82
+#define CSR_HPMCOUNTER3H	0xc83
+#define CSR_HPMCOUNTER4H	0xc84
+#define CSR_HPMCOUNTER5H	0xc85
+#define CSR_HPMCOUNTER6H	0xc86
+#define CSR_HPMCOUNTER7H	0xc87
+#define CSR_HPMCOUNTER8H	0xc88
+#define CSR_HPMCOUNTER9H	0xc89
+#define CSR_HPMCOUNTER10H	0xc8a
+#define CSR_HPMCOUNTER11H	0xc8b
+#define CSR_HPMCOUNTER12H	0xc8c
+#define CSR_HPMCOUNTER13H	0xc8d
+#define CSR_HPMCOUNTER14H	0xc8e
+#define CSR_HPMCOUNTER15H	0xc8f
+#define CSR_HPMCOUNTER16H	0xc90
+#define CSR_HPMCOUNTER17H	0xc91
+#define CSR_HPMCOUNTER18H	0xc92
+#define CSR_HPMCOUNTER19H	0xc93
+#define CSR_HPMCOUNTER20H	0xc94
+#define CSR_HPMCOUNTER21H	0xc95
+#define CSR_HPMCOUNTER22H	0xc96
+#define CSR_HPMCOUNTER23H	0xc97
+#define CSR_HPMCOUNTER24H	0xc98
+#define CSR_HPMCOUNTER25H	0xc99
+#define CSR_HPMCOUNTER26H	0xc9a
+#define CSR_HPMCOUNTER27H	0xc9b
+#define CSR_HPMCOUNTER28H	0xc9c
+#define CSR_HPMCOUNTER29H	0xc9d
+#define CSR_HPMCOUNTER30H	0xc9e
+#define CSR_HPMCOUNTER31H	0xc9f
+
+#define CSR_SSCOUNTOVF		0xda0
 
 #define CSR_SSTATUS		0x100
 #define CSR_SIE			0x104
@@ -241,7 +302,10 @@
 # define RV_IRQ_SOFT		IRQ_S_SOFT
 # define RV_IRQ_TIMER	IRQ_S_TIMER
 # define RV_IRQ_EXT		IRQ_S_EXT
-#endif /* CONFIG_RISCV_M_MODE */
+# define RV_IRQ_PMU	IRQ_PMU_OVF
+# define SIP_LCOFIP     (_AC(0x1, UL) << IRQ_PMU_OVF)
+
+#endif /* !CONFIG_RISCV_M_MODE */
 
 /* IE/IP (Supervisor/Machine Interrupt Enable/Pending) flags */
 #define IE_SIE		(_AC(0x1, UL) << RV_IRQ_SOFT)
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 691fc9c8099b..0734e42f74f2 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -51,6 +51,7 @@ extern unsigned long elf_hwcap;
  * available logical extension id.
  */
 enum riscv_isa_ext_id {
+	RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE,
 	RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
 };
 
diff --git a/arch/riscv/include/asm/perf_event.h b/arch/riscv/include/asm/perf_event.h
index 062efd3a1d5d..d42c901f9a97 100644
--- a/arch/riscv/include/asm/perf_event.h
+++ b/arch/riscv/include/asm/perf_event.h
@@ -9,77 +9,5 @@
 #define _ASM_RISCV_PERF_EVENT_H
 
 #include <linux/perf_event.h>
-#include <linux/ptrace.h>
-#include <linux/interrupt.h>
-
-#ifdef CONFIG_RISCV_BASE_PMU
-#define RISCV_BASE_COUNTERS	2
-
-/*
- * The RISCV_MAX_COUNTERS parameter should be specified.
- */
-
-#define RISCV_MAX_COUNTERS	2
-
-/*
- * These are the indexes of bits in counteren register *minus* 1,
- * except for cycle.  It would be coherent if it can directly mapped
- * to counteren bit definition, but there is a *time* register at
- * counteren[1].  Per-cpu structure is scarce resource here.
- *
- * According to the spec, an implementation can support counter up to
- * mhpmcounter31, but many high-end processors has at most 6 general
- * PMCs, we give the definition to MHPMCOUNTER8 here.
- */
-#define RISCV_PMU_CYCLE		0
-#define RISCV_PMU_INSTRET	1
-#define RISCV_PMU_MHPMCOUNTER3	2
-#define RISCV_PMU_MHPMCOUNTER4	3
-#define RISCV_PMU_MHPMCOUNTER5	4
-#define RISCV_PMU_MHPMCOUNTER6	5
-#define RISCV_PMU_MHPMCOUNTER7	6
-#define RISCV_PMU_MHPMCOUNTER8	7
-
-#define RISCV_OP_UNSUPP		(-EOPNOTSUPP)
-
-struct cpu_hw_events {
-	/* # currently enabled events*/
-	int			n_events;
-	/* currently enabled events */
-	struct perf_event	*events[RISCV_MAX_COUNTERS];
-	/* vendor-defined PMU data */
-	void			*platform;
-};
-
-struct riscv_pmu {
-	struct pmu	*pmu;
-
-	/* generic hw/cache events table */
-	const int	*hw_events;
-	const int	(*cache_events)[PERF_COUNT_HW_CACHE_MAX]
-				       [PERF_COUNT_HW_CACHE_OP_MAX]
-				       [PERF_COUNT_HW_CACHE_RESULT_MAX];
-	/* method used to map hw/cache events */
-	int		(*map_hw_event)(u64 config);
-	int		(*map_cache_event)(u64 config);
-
-	/* max generic hw events in map */
-	int		max_events;
-	/* number total counters, 2(base) + x(general) */
-	int		num_counters;
-	/* the width of the counter */
-	int		counter_width;
-
-	/* vendor-defined PMU features */
-	void		*platform;
-
-	irqreturn_t	(*handle_irq)(int irq_num, void *dev);
-	int		irq;
-};
-
-#endif
-#ifdef CONFIG_PERF_EVENTS
 #define perf_arch_bpf_user_pt_regs(regs) (struct user_regs_struct *)regs
-#endif
-
 #endif /* _ASM_RISCV_PERF_EVENT_H */
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index d1c37479d828..4a430ae60eaa 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -29,6 +29,7 @@ enum sbi_ext_id {
 	SBI_EXT_RFENCE = 0x52464E43,
 	SBI_EXT_HSM = 0x48534D,
 	SBI_EXT_SRST = 0x53525354,
+	SBI_EXT_PMU = 0x504D55,
 
 	/* Experimentals extensions must lie within this range */
 	SBI_EXT_EXPERIMENTAL_START = 0x08000000,
@@ -95,6 +96,98 @@ enum sbi_srst_reset_reason {
 	SBI_SRST_RESET_REASON_SYS_FAILURE,
 };
 
+enum sbi_ext_pmu_fid {
+	SBI_EXT_PMU_NUM_COUNTERS = 0,
+	SBI_EXT_PMU_COUNTER_GET_INFO,
+	SBI_EXT_PMU_COUNTER_CFG_MATCH,
+	SBI_EXT_PMU_COUNTER_START,
+	SBI_EXT_PMU_COUNTER_STOP,
+	SBI_EXT_PMU_COUNTER_FW_READ,
+};
+
+#define RISCV_PMU_RAW_EVENT_MASK GENMASK_ULL(55, 0)
+#define RISCV_PMU_RAW_EVENT_IDX 0x20000
+
+/** 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,
+};
+
+/**
+ * Special "firmware" events provided by the firmware, 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_generic_events_t {
+	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 types */
+enum sbi_pmu_event_type {
+	SBI_PMU_EVENT_TYPE_HW = 0x0,
+	SBI_PMU_EVENT_TYPE_CACHE = 0x1,
+	SBI_PMU_EVENT_TYPE_RAW = 0x2,
+	SBI_PMU_EVENT_TYPE_FW = 0xf,
+};
+
+/* SBI PMU event types */
+enum sbi_pmu_ctr_type {
+	SBI_PMU_CTR_TYPE_HW = 0x0,
+	SBI_PMU_CTR_TYPE_FW,
+};
+
+/* 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_VSNH	(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)
+
 #define SBI_SPEC_VERSION_DEFAULT	0x1
 #define SBI_SPEC_VERSION_MAJOR_SHIFT	24
 #define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
@@ -108,6 +201,8 @@ enum sbi_srst_reset_reason {
 #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
 
 extern unsigned long sbi_spec_version;
 struct sbiret {
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 612556faa527..fb63b462ff85 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -51,7 +51,6 @@ obj-$(CONFIG_MODULE_SECTIONS)	+= module-sections.o
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
-obj-$(CONFIG_RISCV_BASE_PMU)	+= perf_event.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_callchain.o
 obj-$(CONFIG_HAVE_PERF_REGS)	+= perf_regs.o
 obj-$(CONFIG_RISCV_SBI)		+= sbi.o
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index ecc2a09a66a9..d2a936195295 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -87,6 +87,7 @@ int riscv_of_parent_hartid(struct device_node *node)
  *    extensions by an underscore.
  */
 static struct riscv_isa_ext_data isa_ext_arr[] = {
+	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
 	__RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
 };
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index a43c08af5f4b..1b2d42d7f589 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -190,6 +190,8 @@ void __init riscv_fill_hwcap(void)
 			if (!ext_long) {
 				this_hwcap |= isa2hwcap[(unsigned char)(*ext)];
 				set_bit(*ext - 'a', this_isa);
+			} else {
+				SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF);
 			}
 #undef SET_ISA_EXT_MAP
 		}
diff --git a/arch/riscv/kernel/perf_event.c b/arch/riscv/kernel/perf_event.c
deleted file mode 100644
index c835f0362d94..000000000000
--- a/arch/riscv/kernel/perf_event.c
+++ /dev/null
@@ -1,485 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
- * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
- * Copyright (C) 2009 Jaswinder Singh Rajput
- * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
- * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
- * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
- * Copyright (C) 2009 Google, Inc., Stephane Eranian
- * Copyright 2014 Tilera Corporation. All Rights Reserved.
- * Copyright (C) 2018 Andes Technology Corporation
- *
- * Perf_events support for RISC-V platforms.
- *
- * Since the spec. (as of now, Priv-Spec 1.10) does not provide enough
- * functionality for perf event to fully work, this file provides
- * the very basic framework only.
- *
- * For platform portings, please check Documentations/riscv/pmu.txt.
- *
- * The Copyright line includes x86 and tile ones.
- */
-
-#include <linux/kprobes.h>
-#include <linux/kernel.h>
-#include <linux/kdebug.h>
-#include <linux/mutex.h>
-#include <linux/bitmap.h>
-#include <linux/irq.h>
-#include <linux/perf_event.h>
-#include <linux/atomic.h>
-#include <linux/of.h>
-#include <asm/perf_event.h>
-
-static const struct riscv_pmu *riscv_pmu __read_mostly;
-static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
-
-/*
- * Hardware & cache maps and their methods
- */
-
-static const int riscv_hw_event_map[] = {
-	[PERF_COUNT_HW_CPU_CYCLES]		= RISCV_PMU_CYCLE,
-	[PERF_COUNT_HW_INSTRUCTIONS]		= RISCV_PMU_INSTRET,
-	[PERF_COUNT_HW_CACHE_REFERENCES]	= RISCV_OP_UNSUPP,
-	[PERF_COUNT_HW_CACHE_MISSES]		= RISCV_OP_UNSUPP,
-	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= RISCV_OP_UNSUPP,
-	[PERF_COUNT_HW_BRANCH_MISSES]		= RISCV_OP_UNSUPP,
-	[PERF_COUNT_HW_BUS_CYCLES]		= RISCV_OP_UNSUPP,
-};
-
-#define C(x) PERF_COUNT_HW_CACHE_##x
-static const int riscv_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
-[PERF_COUNT_HW_CACHE_OP_MAX]
-[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
-	[C(L1D)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-	[C(L1I)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-	[C(LL)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-	[C(DTLB)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] =  RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] =  RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-	[C(ITLB)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-	[C(BPU)] = {
-		[C(OP_READ)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_WRITE)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-		[C(OP_PREFETCH)] = {
-			[C(RESULT_ACCESS)] = RISCV_OP_UNSUPP,
-			[C(RESULT_MISS)] = RISCV_OP_UNSUPP,
-		},
-	},
-};
-
-static int riscv_map_hw_event(u64 config)
-{
-	if (config >= riscv_pmu->max_events)
-		return -EINVAL;
-
-	return riscv_pmu->hw_events[config];
-}
-
-static int riscv_map_cache_decode(u64 config, unsigned int *type,
-			   unsigned int *op, unsigned int *result)
-{
-	return -ENOENT;
-}
-
-static int riscv_map_cache_event(u64 config)
-{
-	unsigned int type, op, result;
-	int err = -ENOENT;
-		int code;
-
-	err = riscv_map_cache_decode(config, &type, &op, &result);
-	if (!riscv_pmu->cache_events || err)
-		return err;
-
-	if (type >= PERF_COUNT_HW_CACHE_MAX ||
-	    op >= PERF_COUNT_HW_CACHE_OP_MAX ||
-	    result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
-		return -EINVAL;
-
-	code = (*riscv_pmu->cache_events)[type][op][result];
-	if (code == RISCV_OP_UNSUPP)
-		return -EINVAL;
-
-	return code;
-}
-
-/*
- * Low-level functions: reading/writing counters
- */
-
-static inline u64 read_counter(int idx)
-{
-	u64 val = 0;
-
-	switch (idx) {
-	case RISCV_PMU_CYCLE:
-		val = csr_read(CSR_CYCLE);
-		break;
-	case RISCV_PMU_INSTRET:
-		val = csr_read(CSR_INSTRET);
-		break;
-	default:
-		WARN_ON_ONCE(idx < 0 ||	idx > RISCV_MAX_COUNTERS);
-		return -EINVAL;
-	}
-
-	return val;
-}
-
-static inline void write_counter(int idx, u64 value)
-{
-	/* currently not supported */
-	WARN_ON_ONCE(1);
-}
-
-/*
- * pmu->read: read and update the counter
- *
- * Other architectures' implementation often have a xxx_perf_event_update
- * routine, which can return counter values when called in the IRQ, but
- * return void when being called by the pmu->read method.
- */
-static void riscv_pmu_read(struct perf_event *event)
-{
-	struct hw_perf_event *hwc = &event->hw;
-	u64 prev_raw_count, new_raw_count;
-	u64 oldval;
-	int idx = hwc->idx;
-	u64 delta;
-
-	do {
-		prev_raw_count = local64_read(&hwc->prev_count);
-		new_raw_count