riscv: Add SiFive xsfvqmaccdod and xsfvqmaccqoq vendor extensions

Add SiFive vendor extension support to the kernel with the target of
"xsfvqmaccdod" and "xsfvqmaccqoq".

Signed-off-by: Cyan Yang <cyan.yang@sifive.com>
Link: https://lore.kernel.org/r/20250418053239.4351-3-cyan.yang@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

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"

arch/riscv/include/asm/vendor_extensions/sifive.h

@@ -0,0 +1,14 @@
+/* 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
+
+extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_sifive;
+
+#endif

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;

arch/riscv/kernel/vendor_extensions/Makefile

@@ -1,5 +1,6 @@
 # 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-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD)	+= thead.o
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD)	+= thead_hwprobe.o

arch/riscv/kernel/vendor_extensions/sifive.c

@@ -0,0 +1,19 @@
+// 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 */
+const struct riscv_isa_ext_data riscv_isa_vendor_ext_sifive[] = {
+	__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,
+};