linux-riscv · linux-riscv-bot · May 16, 2025 · May 16, 2025 · May 16, 2025 · May 16, 2025
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
@@ -335,3 +335,25 @@ The following keys are defined:
 
 * :c:macro:`RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE`: An unsigned int which
   represents the size of the Zicbom block in bytes.
+
+* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0`: A bitmask containing the
+  sifive vendor extensions that are compatible with the
+  :c:macro:`RISCV_HWPROBE_BASE_BEHAVIOR_IMA`: base system behavior.
+
+  * SIFIVE
+
+    * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XSFVQMACCDOD`: The Xsfqmaccdod vendor
+        extension is supported in version 1.1 of SiFive Int8 Matrix Multiplication
+	Extensions Specification.
+
+    * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XSFVQMACCQOQ`: The Xsfqmaccqoq vendor
+        extension is supported in version 1.1 of SiFive Int8 Matrix Multiplication
+	Instruction Extensions Specification.
+
+    * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XSFVFNRCLIPXFQF`: The Xsfvfnrclipxfqf
+        vendor extension is supported in version 1.0 of SiFive FP32-to-int8 Ranged
+	Clip Instructions Extensions Specification.
+
+    * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XSFVFWMACCQQQ`: The Xsfvfwmaccqqq
+        vendor extension is supported in version 1.0 of Matrix Multiply Accumulate
+	Instruction Extensions Specification.
diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -662,6 +662,31 @@ properties:
             Registers in the AX45MP datasheet.
             https://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf
 
+        # SiFive
+        - const: xsfvqmaccdod
+          description:
+            SiFive Int8 Matrix Multiplication Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/sifive-int8-matrix-multiplication-extensions-specification
+
+        - const: xsfvqmaccqoq
+          description:
+            SiFive Int8 Matrix Multiplication Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/sifive-int8-matrix-multiplication-extensions-specification
+
+        - const: xsfvfnrclipxfqf
+          description:
+            SiFive FP32-to-int8 Ranged Clip Instructions Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/fp32-to-int8-ranged-clip-instructions
+
+        - const: xsfvfwmaccqqq
+          description:
+            SiFive Matrix Multiply Accumulate Instruction Extensions Specification.
+            See more details in
+            https://www.sifive.com/document-file/matrix-multiply-accumulate-instruction
+
         # T-HEAD
         - const: xtheadvector
           description:

diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
@@ -16,6 +16,19 @@ config RISCV_ISA_VENDOR_EXT_ANDES
 	  If you don't know what to do here, say Y.
 endmenu
 
+menu "SiFive"
+config RISCV_ISA_VENDOR_EXT_SIFIVE
+	bool "SiFive vendor extension support"
+	select RISCV_ISA_VENDOR_EXT
+	default y
+	help
+	  Say N here if you want to disable all SiFive vendor extension
+	  support. This will cause any SiFive vendor extensions that are
+	  requested by hardware probing to be ignored.
+
+	  If you don't know what to do here, say Y.
+endmenu
+
 menu "T-Head"
 config RISCV_ISA_VENDOR_EXT_THEAD
 	bool "T-Head vendor extension support"

diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
@@ -8,7 +8,7 @@
 
 #include <uapi/asm/hwprobe.h>
 
-#define RISCV_HWPROBE_MAX_KEY 12
+#define RISCV_HWPROBE_MAX_KEY 13
 
 static inline bool riscv_hwprobe_key_is_valid(__s64 key)
 {
@@ -22,6 +22,7 @@ static inline bool hwprobe_key_is_bitmask(__s64 key)
 	case RISCV_HWPROBE_KEY_IMA_EXT_0:
 	case RISCV_HWPROBE_KEY_CPUPERF_0:
 	case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
+	case RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0:
 		return true;
 	}
 

diff --git a/arch/riscv/include/asm/vendor_extensions/sifive.h b/arch/riscv/include/asm/vendor_extensions/sifive.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_SIFIVE_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_SIFIVE_H
+
+#include <asm/vendor_extensions.h>
+
+#include <linux/types.h>
+
+#define RISCV_ISA_VENDOR_EXT_XSFVQMACCDOD		0
+#define RISCV_ISA_VENDOR_EXT_XSFVQMACCQOQ		1
+#define RISCV_ISA_VENDOR_EXT_XSFVFNRCLIPXFQF		2
+#define RISCV_ISA_VENDOR_EXT_XSFVFWMACCQQQ		3
+
+extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_sifive;
+
+#endif
diff --git a/arch/riscv/include/asm/vendor_extensions/sifive_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/sifive_hwprobe.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_SIFIVE_HWPROBE_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_SIFIVE_HWPROBE_H
+
+#include <linux/cpumask.h>
+
+#include <uapi/asm/hwprobe.h>
+
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE
+void hwprobe_isa_vendor_ext_sifive_0(struct riscv_hwprobe *pair, const struct cpumask *cpus);
+#else
+static inline void hwprobe_isa_vendor_ext_sifive_0(struct riscv_hwprobe *pair,
+						   const struct cpumask *cpus)
+{
+	pair->value = 0;
+}
+#endif
+
+#endif
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -104,6 +104,7 @@ struct riscv_hwprobe {
 #define		RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED	4
 #define RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0	11
 #define RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE	12
+#define RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0	13
 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
 
 /* Flags */

diff --git a/arch/riscv/include/uapi/asm/vendor/sifive.h b/arch/riscv/include/uapi/asm/vendor/sifive.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#define	RISCV_HWPROBE_VENDOR_EXT_XSFVQMACCDOD		(1 << 0)
+#define	RISCV_HWPROBE_VENDOR_EXT_XSFVQMACCQOQ		(1 << 1)
+#define	RISCV_HWPROBE_VENDOR_EXT_XSFVFNRCLIPXFQF		(1 << 2)
+#define	RISCV_HWPROBE_VENDOR_EXT_XSFVFWMACCQQQ		(1 << 3)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
@@ -15,6 +15,7 @@
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/vector.h>
+#include <asm/vendor_extensions/sifive_hwprobe.h>
 #include <asm/vendor_extensions/thead_hwprobe.h>
 #include <vdso/vsyscall.h>
 
@@ -300,6 +301,10 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
 		pair->value = riscv_timebase;
 		break;
 
+	case RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0:
+		hwprobe_isa_vendor_ext_sifive_0(pair, cpus);
+		break;
+
 	case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
 		hwprobe_isa_vendor_ext_thead_0(pair, cpus);
 		break;

diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
@@ -6,6 +6,7 @@
 #include <asm/vendorid_list.h>
 #include <asm/vendor_extensions.h>
 #include <asm/vendor_extensions/andes.h>
+#include <asm/vendor_extensions/sifive.h>
 #include <asm/vendor_extensions/thead.h>
 
 #include <linux/array_size.h>
@@ -15,6 +16,9 @@ struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[] = {
 #ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
 	&riscv_isa_vendor_ext_list_andes,
 #endif
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE
+	&riscv_isa_vendor_ext_list_sifive,
+#endif
 #ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
 	&riscv_isa_vendor_ext_list_thead,
 #endif
@@ -45,6 +49,12 @@ bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsig
 		cpu_bmap = riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap;
 		break;
 	#endif
+	#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE
+	case SIFIVE_VENDOR_ID:
+		bmap = &riscv_isa_vendor_ext_list_sifive.all_harts_isa_bitmap;
+		cpu_bmap = riscv_isa_vendor_ext_list_sifive.per_hart_isa_bitmap;
+		break;
+	#endif
 	#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
 	case THEAD_VENDOR_ID:
 		bmap = &riscv_isa_vendor_ext_list_thead.all_harts_isa_bitmap;

diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE)	+= sifive.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE)	+= sifive_hwprobe.o
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD)	+= thead.o
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD)	+= thead_hwprobe.o
diff --git a/arch/riscv/kernel/vendor_extensions/sifive.c b/arch/riscv/kernel/vendor_extensions/sifive.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/cpufeature.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/sifive.h>
+
+#include <linux/array_size.h>
+#include <linux/types.h>
+
+/* All SiFive vendor extensions supported in Linux */
+static const struct riscv_isa_ext_data riscv_isa_vendor_ext_sifive[] = {
+	__RISCV_ISA_EXT_DATA(xsfvfnrclipxfqf, RISCV_ISA_VENDOR_EXT_XSFVFNRCLIPXFQF),
+	__RISCV_ISA_EXT_DATA(xsfvfwmaccqqq, RISCV_ISA_VENDOR_EXT_XSFVFWMACCQQQ),
+	__RISCV_ISA_EXT_DATA(xsfvqmaccdod, RISCV_ISA_VENDOR_EXT_XSFVQMACCDOD),
+	__RISCV_ISA_EXT_DATA(xsfvqmaccqoq, RISCV_ISA_VENDOR_EXT_XSFVQMACCQOQ),
+};
+
+struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_sifive = {
+	.ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_sifive),
+	.ext_data = riscv_isa_vendor_ext_sifive,
+};
diff --git a/arch/riscv/kernel/vendor_extensions/sifive_hwprobe.c b/arch/riscv/kernel/vendor_extensions/sifive_hwprobe.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/vendor_extensions/sifive.h>
+#include <asm/vendor_extensions/sifive_hwprobe.h>
+#include <asm/vendor_extensions/vendor_hwprobe.h>
+
+#include <linux/cpumask.h>
+#include <linux/types.h>
+
+#include <uapi/asm/hwprobe.h>
+#include <uapi/asm/vendor/sifive.h>
+
+void hwprobe_isa_vendor_ext_sifive_0(struct riscv_hwprobe *pair, const struct cpumask *cpus)
+{
+	VENDOR_EXTENSION_SUPPORTED(pair, cpus,
+				   riscv_isa_vendor_ext_list_sifive.per_hart_isa_bitmap, {
+		VENDOR_EXT_KEY(XSFVQMACCDOD);
+		VENDOR_EXT_KEY(XSFVQMACCQOQ);
+		VENDOR_EXT_KEY(XSFVFNRCLIPXFQF);
+		VENDOR_EXT_KEY(XSFVFWMACCQQQ);
+	});
+}