[PW_SID:1119561] Add Counter delegation ISA extension support

Documentation/devicetree/bindings/riscv/extensions.yaml

@@ -181,6 +181,27 @@ properties:
             changes to interrupts as frozen at commit ccbddab ("Merge pull
             request #42 from riscv/jhauser-2023-RC4") of riscv-aia.
 
+        - const: smcdeleg
+          description: |
+            The standard Smcdeleg machine-level extension for the machine mode
+            to delegate the hpmcounters to supervisor mode so that they are
+            directly accessible in the supervisor mode as ratified in the
+            20240213 version of the privileged ISA specification.
+
+        - const: smcntrpmf
+          description: |
+            The standard Smcntrpmf machine-level extension for the machine mode
+            to enable privilege mode filtering for cycle and instret counters as
+            ratified in the 20240326 version of the privileged ISA specification.
+
+        - const: smcsrind
+          description: |
+            The standard Smcsrind machine-level extension extends the
+            indirect CSR access mechanism defined by the Smaia extension. This
+            extension allows other ISA extensions to use indirect CSR access
+            mechanism in M-mode as ratified in the 20240326 version of the
+            privileged ISA specification.
+
         - const: smmpm
           description: |
             The standard Smmpm extension for M-mode pointer masking as
@@ -206,6 +227,14 @@ properties:
             behavioural changes to interrupts as frozen at commit ccbddab
             ("Merge pull request #42 from riscv/jhauser-2023-RC4") of riscv-aia.
 
+        - const: ssccfg
+          description: |
+            The standard Ssccfg supervisor-level extension for configuring
+            the delegated hpmcounters to be accessible directly in supervisor
+            mode as ratified in the 20240213 version of the privileged ISA
+            specification. This extension depends on Sscsrind, Smcdeleg, Zihpm,
+            Zicntr extensions.
+
         - const: ssccptr
           description: |
             The standard Ssccptr extension for main memory (cacheability and
@@ -226,6 +255,14 @@ properties:
             Profiles Version 1.0, with commit b1d806605f87 ("Updated to
             ratified state.")
 
+        - const: sscsrind
+          description: |
+            The standard Sscsrind supervisor-level extension extends the
+            indirect CSR access mechanism defined by the Ssaia extension. This
+            extension allows other ISA extensions to use indirect CSR access
+            mechanism in S-mode as ratified in the 20240326 version of the
+            privileged ISA specification.
+
         - const: ssnpm
           description: |
             The standard Ssnpm extension for next-mode pointer masking as
@@ -1113,6 +1150,32 @@ properties:
             allOf:
               - const: zilsd
               - const: zca
+      # Smcdeleg depends on Sscsrind, Zihpm, Zicntr
+      - if:
+          contains:
+            const: smcdeleg
+        then:
+          allOf:
+            - contains:
+                const: sscsrind
+            - contains:
+                const: zihpm
+            - contains:
+                const: zicntr
+      # Ssccfg depends on Smcdeleg, Sscsrind, Zihpm, Zicntr
+      - if:
+          contains:
+            const: ssccfg
+        then:
+          allOf:
+            - contains:
+                const: smcdeleg
+            - contains:
+                const: sscsrind
+            - contains:
+                const: zihpm
+            - contains:
+                const: zicntr
 
 allOf:
   # Zcf extension does not exist on rv64

arch/riscv/include/asm/csr.h

@@ -241,6 +241,24 @@
 #define SMSTATEEN0_HSENVCFG		(_ULL(1) << SMSTATEEN0_HSENVCFG_SHIFT)
 #define SMSTATEEN0_SSTATEEN0_SHIFT	63
 #define SMSTATEEN0_SSTATEEN0		(_ULL(1) << SMSTATEEN0_SSTATEEN0_SHIFT)
+/* HPMEVENT bits. These are accessible in S-mode via Smcdeleg/Ssccfg */
+#define HPMEVENT_OF			(BIT_ULL(63))
+#define HPMEVENT_MINH			(BIT_ULL(62))
+#define HPMEVENT_SINH			(BIT_ULL(61))
+#define HPMEVENT_UINH			(BIT_ULL(60))
+#define HPMEVENT_VSINH			(BIT_ULL(59))
+#define HPMEVENT_VUINH			(BIT_ULL(58))
+#ifndef CONFIG_64BIT
+#define HPMEVENTH_OF			(BIT(31))
+#define HPMEVENTH_MINH			(BIT(30))
+#define HPMEVENTH_SINH			(BIT(29))
+#define HPMEVENTH_UINH			(BIT(28))
+#define HPMEVENTH_VSINH			(BIT(27))
+#define HPMEVENTH_VUINH			(BIT(26))
+#endif
+
+#define SISELECT_SSCCFG_BASE		0x40
+#define HPMEVENT_MASK			GENMASK_ULL(63, 56)
 
 /* mseccfg bits */
 #define MSECCFG_PMM			ENVCFG_PMM
@@ -322,6 +340,7 @@
 #define CSR_SCOUNTEREN		0x106
 #define CSR_SENVCFG		0x10a
 #define CSR_SSTATEEN0		0x10c
+#define CSR_SCOUNTINHIBIT	0x120
 #define CSR_SSCRATCH		0x140
 #define CSR_SEPC		0x141
 #define CSR_SCAUSE		0x142
@@ -347,6 +366,12 @@
 /* Supervisor-Level Window to Indirectly Accessed Registers (AIA) */
 #define CSR_SISELECT		0x150
 #define CSR_SIREG		0x151
+/* Supervisor-Level Window to Indirectly Accessed Registers (Sxcsrind) */
+#define CSR_SIREG2		0x152
+#define CSR_SIREG3		0x153
+#define CSR_SIREG4		0x155
+#define CSR_SIREG5		0x156
+#define CSR_SIREG6		0x157
 
 /* Supervisor-Level Interrupts (AIA) */
 #define CSR_STOPEI		0x15c
@@ -394,6 +419,14 @@
 /* VS-Level Window to Indirectly Accessed Registers (H-extension with AIA) */
 #define CSR_VSISELECT		0x250
 #define CSR_VSIREG		0x251
+/*
+ * VS-Level Window to Indirectly Accessed Registers (H-extension with Sxcsrind)
+ */
+#define CSR_VSIREG2		0x252
+#define CSR_VSIREG3		0x253
+#define CSR_VSIREG4		0x255
+#define CSR_VSIREG5		0x256
+#define CSR_VSIREG6		0x257
 
 /* VS-Level Interrupts (H-extension with AIA) */
 #define CSR_VSTOPEI		0x25c
@@ -436,6 +469,12 @@
 /* Machine-Level Window to Indirectly Accessed Registers (AIA) */
 #define CSR_MISELECT		0x350
 #define CSR_MIREG		0x351
+/* Machine-Level Window to Indirectly Accessed Registers (Sxcsrind) */
+#define CSR_MIREG2		0x352
+#define CSR_MIREG3		0x353
+#define CSR_MIREG4		0x355
+#define CSR_MIREG5		0x356
+#define CSR_MIREG6		0x357
 
 /* Machine-Level Interrupts (AIA) */
 #define CSR_MTOPEI		0x35c
@@ -498,6 +537,11 @@
 # define CSR_IEH		CSR_MIEH
 # define CSR_ISELECT	CSR_MISELECT
 # define CSR_IREG	CSR_MIREG
+# define CSR_IREG2	CSR_MIREG2
+# define CSR_IREG3	CSR_MIREG3
+# define CSR_IREG4	CSR_MIREG4
+# define CSR_IREG5	CSR_MIREG5
+# define CSR_IREG6	CSR_MIREG6
 # define CSR_IPH		CSR_MIPH
 # define CSR_TOPEI	CSR_MTOPEI
 # define CSR_TOPI	CSR_MTOPI
@@ -523,6 +567,11 @@
 # define CSR_IEH		CSR_SIEH
 # define CSR_ISELECT	CSR_SISELECT
 # define CSR_IREG	CSR_SIREG
+# define CSR_IREG2	CSR_SIREG2
+# define CSR_IREG3	CSR_SIREG3
+# define CSR_IREG4	CSR_SIREG4
+# define CSR_IREG5	CSR_SIREG5
+# define CSR_IREG6	CSR_SIREG6
 # define CSR_IPH		CSR_SIPH
 # define CSR_TOPEI	CSR_STOPEI
 # define CSR_TOPI	CSR_STOPI

arch/riscv/include/asm/csr_ind.h

@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_RISCV_CSR_IND_H
+#define _ASM_RISCV_CSR_IND_H
+
+#include <linux/irqflags.h>
+
+#include <asm/csr.h>
+
+#define csr_ind_read(iregcsr, iselbase, iseloff) ({		\
+	unsigned long __value = 0;				\
+	unsigned long __flags;					\
+	local_irq_save(__flags);				\
+	csr_write(CSR_ISELECT, (iselbase) + (iseloff));		\
+	__value = csr_read(iregcsr);				\
+	local_irq_restore(__flags);				\
+	__value;						\
+})
+
+#define csr_ind_write(iregcsr, iselbase, iseloff, value) ({	\
+	unsigned long __flags;					\
+	local_irq_save(__flags);				\
+	csr_write(CSR_ISELECT, (iselbase) + (iseloff));		\
+	csr_write(iregcsr, (value));				\
+	local_irq_restore(__flags);				\
+})
+
+#define csr_ind_warl(iregcsr, iselbase, iseloff, warl_val) ({	\
+	unsigned long __old_val = 0, __value = 0;		\
+	unsigned long __flags;					\
+	local_irq_save(__flags);				\
+	csr_write(CSR_ISELECT, (iselbase) + (iseloff));		\
+	__old_val = csr_read(iregcsr);				\
+	csr_write(iregcsr, (warl_val));				\
+	__value = csr_read(iregcsr);				\
+	csr_write(iregcsr, __old_val);				\
+	local_irq_restore(__flags);				\
+	__value;						\
+})
+
+#endif

arch/riscv/include/asm/hwcap.h

@@ -112,6 +112,11 @@
 #define RISCV_ISA_EXT_ZCLSD		103
 #define RISCV_ISA_EXT_ZICFILP		104
 #define RISCV_ISA_EXT_ZICFISS		105
+#define RISCV_ISA_EXT_SSCSRIND		106
+#define RISCV_ISA_EXT_SMCSRIND		107
+#define RISCV_ISA_EXT_SMCNTRPMF		108
+#define RISCV_ISA_EXT_SSCCFG		109
+#define RISCV_ISA_EXT_SMCDELEG		110
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
@@ -121,9 +126,11 @@
 #ifdef CONFIG_RISCV_M_MODE
 #define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SMAIA
 #define RISCV_ISA_EXT_SUPM		RISCV_ISA_EXT_SMNPM
+#define RISCV_ISA_EXT_SxCSRIND		RISCV_ISA_EXT_SMCSRIND
 #else
 #define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SSAIA
 #define RISCV_ISA_EXT_SUPM		RISCV_ISA_EXT_SSNPM
+#define RISCV_ISA_EXT_SxCSRIND		RISCV_ISA_EXT_SSCSRIND
 #endif
 
 #endif /* _ASM_RISCV_HWCAP_H */

arch/riscv/include/asm/vendorid_list.h

@@ -11,4 +11,10 @@
 #define SIFIVE_VENDOR_ID	0x489
 #define THEAD_VENDOR_ID		0x5b7
 
+#define QEMU_VIRT_VENDOR_ID		0x000
+#define QEMU_VIRT_IMPL_ID		0x000
+#define QEMU_VIRT_ARCH_ID		0x000
+/* Newer Qemu reports the spec-allocated marchid 0x2a (42) for non-vendor CPUs */
+#define QEMU_VIRT_ARCH_ID_SPEC		0x2a
+
 #endif

arch/riscv/kernel/cpufeature.c

@@ -330,6 +330,27 @@ static const unsigned int riscv_a_exts[] = {
 	RISCV_ISA_EXT_ZKNE,	\
 	RISCV_ISA_EXT_ZKNH
 
+static int riscv_ext_smcdeleg_validate(const struct riscv_isa_ext_data *data,
+				       const unsigned long *isa_bitmap)
+{
+	if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SSCSRIND) &&
+	    __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZIHPM) &&
+	    __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZICNTR))
+		return 0;
+
+	return -EPROBE_DEFER;
+}
+
+static int riscv_ext_ssccfg_validate(const struct riscv_isa_ext_data *data,
+				     const unsigned long *isa_bitmap)
+{
+	if (!riscv_ext_smcdeleg_validate(data, isa_bitmap) &&
+	    __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SMCDELEG))
+		return 0;
+
+	return -EPROBE_DEFER;
+}
+
 static const unsigned int riscv_zk_bundled_exts[] = {
 	RISCV_ISA_EXT_ZKN,
 	RISCV_ISA_EXT_ZKR,
@@ -576,11 +597,17 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_BUNDLE_VALIDATE(zvksg, riscv_zvksg_bundled_exts, riscv_ext_vector_crypto_validate),
 	__RISCV_ISA_EXT_DATA_VALIDATE(zvkt, RISCV_ISA_EXT_ZVKT, riscv_ext_vector_crypto_validate),
 	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+	__RISCV_ISA_EXT_DATA_VALIDATE(smcdeleg, RISCV_ISA_EXT_SMCDELEG,
+				      riscv_ext_smcdeleg_validate),
+	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
+	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
 	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
 	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
 	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
 	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
+	__RISCV_ISA_EXT_DATA_VALIDATE(ssccfg, RISCV_ISA_EXT_SSCCFG, riscv_ext_ssccfg_validate),
 	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
+	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
 	__RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),
 	__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
 	__RISCV_ISA_EXT_DATA(svade, RISCV_ISA_EXT_SVADE),

drivers/perf/Kconfig

@@ -97,13 +97,17 @@ config RISCV_PMU_LEGACY
 
 config RISCV_PMU_SBI
 	depends on RISCV_PMU && RISCV_SBI
-	bool "RISC-V PMU based on SBI PMU extension"
+	bool "RISC-V PMU based on SBI PMU extension and/or counter delegation"
 	default y
 	help
-	  Say y if you want to use the CPU performance monitor
-	  using SBI PMU extension on RISC-V based systems. This option provides
-	  full perf feature support i.e. counter overflow, privilege mode
-	  filtering, counter configuration.
+	  Say y if you want to use the CPU performance monitor on RISC-V based
+	  systems. This single driver supports both hardware counter access
+	  mechanisms: it uses the counter delegation (Smcdeleg/Ssccfg) ISA
+	  extension to program and read the hpmcounters directly in supervisor
+	  mode when available, and uses the SBI PMU extension for firmware
+	  counters and when counter delegation is not present. This option
+	  provides full perf feature support i.e. counter overflow, privilege
+	  mode filtering, counter configuration.
 
 config STARFIVE_STARLINK_PMU
 	depends on ARCH_STARFIVE || COMPILE_TEST