[PATCH v5 0/7] riscv: Add support for xmipsexectl

[PATCH v5 0/7] riscv: Add support for xmipsexectl

[Aleksa Paunovic via B4 Relay]

This patch series adds support for the xmipsexectl vendor extension.
A new hardware probe key has also been added to allow userspace to probe for MIPS vendor extensions.

Additionally, since the standard Zihintpause PAUSE instruction encoding is not supported on some MIPS CPUs,
an errata was implemented for replacing this instruction with the xmipsexectl MIPS.PAUSE alternative encoding.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
---
Changes in v5:
- Add MIPS.IHB and MIPS.EHB instructions
- Rebase on alex-for-next
- Address other smaller comments pointed out by Alexandre
- Link to v4: https://lore.kernel.org/r/20250625-p8700-pause-v4-0-6c7dd7f85756@htecgroup.com

This is a continuation of a previous series, which did not implement the full
xmipsexectl vendor extension. The title was updated accordingly.

Changes in v4:
- Add support for the xmipsexectl vendor extension
- Remove the ifdef/else from errata_list.h
- Replace the ifdef/else with a hwprobe call in the userspace code.

Link to v3:
https://lore.kernel.org/linux-riscv/20250129131703.733098-1-arikalo@gmail.com/

---
Aleksa Paunovic (6):
      dt-bindings: riscv: Add xmipsexectl ISA extension description
      riscv: Add xmipsexectl as a vendor extension
      riscv: Add xmipsexectl instructions
      riscv: hwprobe: Add MIPS vendor extension probing
      riscv: hwprobe: Document MIPS xmipsexectl vendor extension
      riscv: Add tools support for xmipsexectl

Djordje Todorovic (1):
      riscv: errata: Fix the PAUSE Opcode for MIPS P8700

 Documentation/arch/riscv/hwprobe.rst               |  9 +++
 .../devicetree/bindings/riscv/extensions.yaml      |  6 ++
 arch/riscv/Kconfig.errata                          | 23 ++++++++
 arch/riscv/Kconfig.vendor                          | 13 +++++
 arch/riscv/errata/Makefile                         |  1 +
 arch/riscv/errata/mips/Makefile                    |  5 ++
 arch/riscv/errata/mips/errata.c                    | 67 ++++++++++++++++++++++
 arch/riscv/include/asm/alternative.h               |  3 +
 arch/riscv/include/asm/cmpxchg.h                   |  3 +-
 arch/riscv/include/asm/errata_list.h               | 13 ++++-
 arch/riscv/include/asm/errata_list_vendors.h       |  5 ++
 arch/riscv/include/asm/hwprobe.h                   |  3 +-
 arch/riscv/include/asm/vdso/processor.h            |  3 +-
 arch/riscv/include/asm/vendor_extensions/mips.h    | 37 ++++++++++++
 .../include/asm/vendor_extensions/mips_hwprobe.h   | 22 +++++++
 arch/riscv/include/asm/vendorid_list.h             |  1 +
 arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
 arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +
 arch/riscv/kernel/alternative.c                    |  5 ++
 arch/riscv/kernel/sys_hwprobe.c                    |  4 ++
 arch/riscv/kernel/vendor_extensions.c              | 10 ++++
 arch/riscv/kernel/vendor_extensions/Makefile       |  2 +
 arch/riscv/kernel/vendor_extensions/mips.c         | 22 +++++++
 arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 23 ++++++++
 arch/riscv/mm/init.c                               |  1 +
 tools/arch/riscv/include/asm/vdso/processor.h      | 27 +++++----
 26 files changed, 298 insertions(+), 14 deletions(-)
---
base-commit: b6a4bae2f16162876842127d7507dad84e404f8f
change-id: 20250424-p8700-pause-dcb649968e24

Best regards,
-- 
Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

[PATCH v5 1/7] dt-bindings: riscv: Add xmipsexectl ISA extension description

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

The xmipsexectl extension is described in the MIPS RV64 P8700/P8700-F
Multiprocessing System Programmer’s Guide linked at [1].

Link: https://mips.com/wp-content/uploads/2025/06/P8700_Programmers_Reference_Manual_Rev1.84_5-31-2025.pdf

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
 Documentation/devicetree/bindings/riscv/extensions.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index ede6a58ccf5347d92785dc085a011052c1aade14..de41a6f074d3af2ceaf5293dfe75d16f43d416d6 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -662,6 +662,12 @@ properties:
             Registers in the AX45MP datasheet.
             https://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf
 
+        # MIPS
+        - const: xmipsexectl
+          description:
+            The MIPS extension for execution control as documented in
+            https://mips.com/wp-content/uploads/2025/06/P8700_Programmers_Reference_Manual_Rev1.84_5-31-2025.pdf
+
         # SiFive
         - const: xsfvqmaccdod
           description:

-- 
2.34.1

[PATCH v5 2/7] riscv: Add xmipsexectl as a vendor extension

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Add support for MIPS vendor extensions. Add support for the xmipsexectl
vendor extension.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/Kconfig.vendor                       | 13 +++++++++++++
 arch/riscv/include/asm/vendor_extensions/mips.h | 18 ++++++++++++++++++
 arch/riscv/kernel/vendor_extensions.c           | 10 ++++++++++
 arch/riscv/kernel/vendor_extensions/Makefile    |  1 +
 arch/riscv/kernel/vendor_extensions/mips.c      | 22 ++++++++++++++++++++++
 5 files changed, 64 insertions(+)

diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
index e14f26368963c178e3271e0f716b27fff7671e78..3c1f92e406c3f21481b56e61229716fd02ab81b2 100644
--- 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 "MIPS"
+config RISCV_ISA_VENDOR_EXT_MIPS
+	bool "MIPS vendor extension support"
+	select RISCV_ISA_VENDOR_EXT
+	default y
+	help
+	  Say N here to disable detection of and support for all MIPS vendor
+	  extensions. Without this option enabled, MIPS vendor extensions will
+	  not be detected at boot and their presence not reported to userspace.
+
+	  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"
diff --git a/arch/riscv/include/asm/vendor_extensions/mips.h b/arch/riscv/include/asm/vendor_extensions/mips.h
new file mode 100644
index 0000000000000000000000000000000000000000..133e55985d827ce7d6057004b590bdcbbdb1ec8c
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/mips.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 MIPS.
+ */
+
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_H
+
+#include <linux/types.h>
+
+#define RISCV_ISA_VENDOR_EXT_XMIPSEXECTL	0
+
+#ifndef __ASSEMBLER__
+struct riscv_isa_vendor_ext_data_list;
+extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_mips;
+#endif
+
+#endif // _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_H
diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
index 92d8ff81f42c9ceba63bef0170ab134564a24a4e..bb4a7592368560ebacbcd8a5ce335eea6312ea5c 100644
--- 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/mips.h>
 #include <asm/vendor_extensions/sifive.h>
 #include <asm/vendor_extensions/thead.h>
 
@@ -16,6 +17,9 @@ 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_MIPS
+	&riscv_isa_vendor_ext_list_mips,
+#endif
 #ifdef CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE
 	&riscv_isa_vendor_ext_list_sifive,
 #endif
@@ -49,6 +53,12 @@ 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_MIPS
+	case MIPS_VENDOR_ID:
+		bmap = &riscv_isa_vendor_ext_list_mips.all_harts_isa_bitmap;
+		cpu_bmap = riscv_isa_vendor_ext_list_mips.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;
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
index a4eca96d1c8a2fd165220f6439a3884cf90a9593..ccad4ebafb43412e72e654da3bdb9face53b80c6 100644
--- a/arch/riscv/kernel/vendor_extensions/Makefile
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_MIPS)  	+= mips.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
diff --git a/arch/riscv/kernel/vendor_extensions/mips.c b/arch/riscv/kernel/vendor_extensions/mips.c
new file mode 100644
index 0000000000000000000000000000000000000000..f691129f96c21f2ef089124f4b64a6f0a8e6d4aa
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/mips.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 MIPS.
+ */
+
+#include <asm/cpufeature.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/mips.h>
+
+#include <linux/array_size.h>
+#include <linux/cpumask.h>
+#include <linux/types.h>
+
+/* All MIPS vendor extensions supported in Linux */
+static const struct riscv_isa_ext_data riscv_isa_vendor_ext_mips[] = {
+	__RISCV_ISA_EXT_DATA(xmipsexectl, RISCV_ISA_VENDOR_EXT_XMIPSEXECTL),
+};
+
+struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_mips = {
+	.ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_mips),
+	.ext_data = riscv_isa_vendor_ext_mips,
+};

-- 
2.34.1

[PATCH v5 3/7] riscv: Add xmipsexectl instructions

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Add xmipsexectl instruction opcodes. This includes the MIPS.PAUSE,
MIPS.EHB, and MIPS.IHB instructions.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/include/asm/vendor_extensions/mips.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/riscv/include/asm/vendor_extensions/mips.h b/arch/riscv/include/asm/vendor_extensions/mips.h
index 133e55985d827ce7d6057004b590bdcbbdb1ec8c..ea8ca747d691df2e9ee7e5360f800fbdccfe3945 100644
--- a/arch/riscv/include/asm/vendor_extensions/mips.h
+++ b/arch/riscv/include/asm/vendor_extensions/mips.h
@@ -15,4 +15,23 @@ struct riscv_isa_vendor_ext_data_list;
 extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_mips;
 #endif
 
+/* Extension specific instructions */
+
+/*
+ * All of the xmipsexectl extension instructions are
+ * ‘hint’ encodings of the SLLI instruction,
+ * with rd = 0, rs1 = 0 and imm = 1 for IHB, imm = 3 for EHB,
+ * and imm = 5 for PAUSE.
+ * MIPS.PAUSE is an alternative opcode which is implemented to have the
+ * same behavior as PAUSE on some MIPS RISCV cores.
+ * MIPS.EHB clears all execution hazards before allowing
+ * any subsequent instructions to execute.
+ * MIPS.IHB clears all instruction hazards before
+ * allowing any subsequent instructions to fetch.
+ */
+
+#define MIPS_PAUSE	".4byte 0x00501013\n\t"
+#define MIPS_EHB	".4byte 0x00301013\n\t"
+#define MIPS_IHB	".4byte 0x00101013\n\t"
+
 #endif // _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_H

-- 
2.34.1

[PATCH v5 4/7] riscv: hwprobe: Add MIPS vendor extension probing

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0" which allows
userspace to probe for the new xmipsexectl vendor extension.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/include/asm/hwprobe.h                   |  3 ++-
 .../include/asm/vendor_extensions/mips_hwprobe.h   | 22 +++++++++++++++++++++
 arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
 arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +++
 arch/riscv/kernel/sys_hwprobe.c                    |  4 ++++
 arch/riscv/kernel/vendor_extensions/Makefile       |  1 +
 arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 23 ++++++++++++++++++++++
 7 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 7fe0a379474ae2c64d300d6fee4a012173f6a6d7..948d2b34e94e84e4c2c351ffe91f4b3afcefc3f7 100644
--- 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 13
+#define RISCV_HWPROBE_MAX_KEY 14
 
 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_MIPS_0:
 	case RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0:
 		return true;
 	}
diff --git a/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h
new file mode 100644
index 0000000000000000000000000000000000000000..e63f664b6b1766e5fc3e68fc696607bcf3e31776
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 MIPS.
+ */
+
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
+#define _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
+
+#include <linux/cpumask.h>
+#include <uapi/asm/hwprobe.h>
+
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_MIPS
+void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair, const struct cpumask *cpus);
+#else
+static inline void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair,
+						 const struct cpumask *cpus)
+{
+	pair->value = 0;
+}
+#endif
+
+#endif // _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index aaf6ad97049931381f9542bb9316c873ec6ab9f6..5d30a4fae37a82ef4d968d20b187420772ad8946 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -106,6 +106,7 @@ struct riscv_hwprobe {
 #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
+#define RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0	14
 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
 
 /* Flags */
diff --git a/arch/riscv/include/uapi/asm/vendor/mips.h b/arch/riscv/include/uapi/asm/vendor/mips.h
new file mode 100644
index 0000000000000000000000000000000000000000..11d41651178233a5f06ab9541ea0506d9883aa19
--- /dev/null
+++ b/arch/riscv/include/uapi/asm/vendor/mips.h
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#define RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL	(1 << 0)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 3e9259790816e46092d893df6321deaac3dd9795..000f4451a9d873d5f068986a14615de3a2a5601d 100644
--- 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/mips_hwprobe.h>
 #include <asm/vendor_extensions/sifive_hwprobe.h>
 #include <asm/vendor_extensions/thead_hwprobe.h>
 #include <vdso/vsyscall.h>
@@ -307,6 +308,9 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
 	case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
 		hwprobe_isa_vendor_ext_thead_0(pair, cpus);
 		break;
+	case RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0:
+		hwprobe_isa_vendor_ext_mips_0(pair, cpus);
+		break;
 
 	/*
 	 * For forward compatibility, unknown keys don't fail the whole
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
index ccad4ebafb43412e72e654da3bdb9face53b80c6..bf116c82b6bdb3aee23e27fc0b2a69be7c7a5ccb 100644
--- a/arch/riscv/kernel/vendor_extensions/Makefile
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -2,6 +2,7 @@
 
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
 obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_MIPS)  	+= mips.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_MIPS)  	+= mips_hwprobe.o
 obj-$(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
diff --git a/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c b/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c
new file mode 100644
index 0000000000000000000000000000000000000000..de7aa4a7ff668e18778efcdef77b994178ca85c3
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 MIPS.
+ */
+
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/mips.h>
+#include <asm/vendor_extensions/mips_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/mips.h>
+
+void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair,
+				   const struct cpumask *cpus)
+{
+	VENDOR_EXTENSION_SUPPORTED(
+		pair, cpus, riscv_isa_vendor_ext_list_mips.per_hart_isa_bitmap,
+		{ VENDOR_EXT_KEY(XMIPSEXECTL); });
+}

-- 
2.34.1

[PATCH v5 5/7] riscv: hwprobe: Document MIPS xmipsexectl vendor extension

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Document support for MIPS vendor extensions using the key
"RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0" and xmipsexectl vendor extension
using the key "RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL".

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 Documentation/arch/riscv/hwprobe.rst | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index 2aa9be272d5de1c15559a978a956bc36c34de81c..2f449c9b15bdd6b9813c9a968deca1a4c4ff9b14 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -327,6 +327,15 @@ The following keys are defined:
   * :c:macro:`RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED`: Misaligned vector accesses are
     not supported at all and will generate a misaligned address fault.
 
+* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0`: A bitmask containing the
+  mips vendor extensions that are compatible with the
+  :c:macro:`RISCV_HWPROBE_BASE_BEHAVIOR_IMA`: base system behavior.
+
+  * MIPS
+
+    * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL`: The xmipsexectl vendor
+        extension is supported in the MIPS ISA extensions spec.
+
 * :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0`: A bitmask containing the
   thead vendor extensions that are compatible with the
   :c:macro:`RISCV_HWPROBE_BASE_BEHAVIOR_IMA`: base system behavior.

-- 
2.34.1

[PATCH v5 6/7] riscv: Add tools support for xmipsexectl

[Aleksa Paunovic via B4 Relay]

From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Use the hwprobe syscall to decide which PAUSE instruction to execute in
userspace code.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 tools/arch/riscv/include/asm/vdso/processor.h | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/tools/arch/riscv/include/asm/vdso/processor.h b/tools/arch/riscv/include/asm/vdso/processor.h
index 0665b117f30f2766a23446fbd7c8ce82d1843a93..b089d4be998f4ab7bc43a96496a6c6f1bb38da4d 100644
--- a/tools/arch/riscv/include/asm/vdso/processor.h
+++ b/tools/arch/riscv/include/asm/vdso/processor.h
@@ -4,26 +4,33 @@
 
 #ifndef __ASSEMBLER__
 
+#include <asm/hwprobe.h>
+#include <sys/hwprobe.h>
+#include <asm/vendor/mips.h>
+#include <asm/vendor_extensions/mips.h>
 #include <asm-generic/barrier.h>
 
 static inline void cpu_relax(void)
 {
+	struct riscv_hwprobe pair;
+	bool has_mipspause;
 #ifdef __riscv_muldiv
 	int dummy;
 	/* In lieu of a halt instruction, induce a long-latency stall. */
 	__asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
 #endif
 
-#ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE
-	/*
-	 * Reduce instruction retirement.
-	 * This assumes the PC changes.
-	 */
-	__asm__ __volatile__ ("pause");
-#else
-	/* Encoding of the pause instruction */
-	__asm__ __volatile__ (".4byte 0x100000F");
-#endif
+	pair.key = RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0;
+	__riscv_hwprobe(&pair, 1, 0, NULL, 0);
+	has_mipspause = pair.value & RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL;
+
+	if (has_mipspause) {
+		__asm__ __volatile__(MIPS_PAUSE);
+	} else {
+		/* Encoding of the pause instruction */
+		__asm__ __volatile__(".4byte 0x100000F");
+	}
+
 	barrier();
 }
 

-- 
2.34.1

[PATCH v5 7/7] riscv: errata: Fix the PAUSE Opcode for MIPS P8700

[Aleksa Paunovic via B4 Relay]

From: Djordje Todorovic <djordje.todorovic@htecgroup.com>

Add ERRATA_MIPS and ERRATA_MIPS_P8700_PAUSE_OPCODE configs.
Handle errata for the MIPS PAUSE instruction.

Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com>
Signed-off-by: Aleksandar Rikalo <arikalo@gmail.com>
Signed-off-by: Raj Vishwanathan4 <rvishwanathan@mips.com>
Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/Kconfig.errata                    | 23 ++++++++++
 arch/riscv/errata/Makefile                   |  1 +
 arch/riscv/errata/mips/Makefile              |  5 +++
 arch/riscv/errata/mips/errata.c              | 67 ++++++++++++++++++++++++++++
 arch/riscv/include/asm/alternative.h         |  3 ++
 arch/riscv/include/asm/cmpxchg.h             |  3 +-
 arch/riscv/include/asm/errata_list.h         | 13 +++++-
 arch/riscv/include/asm/errata_list_vendors.h |  5 +++
 arch/riscv/include/asm/vdso/processor.h      |  3 +-
 arch/riscv/include/asm/vendorid_list.h       |  1 +
 arch/riscv/kernel/alternative.c              |  5 +++
 arch/riscv/mm/init.c                         |  1 +
 12 files changed, 127 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata
index d2c982ba5373041a2d680f7fd5bced6d98357bdd..ac64123433e717d3cd4a6d107f1328d27297f9cc 100644
--- a/arch/riscv/Kconfig.errata
+++ b/arch/riscv/Kconfig.errata
@@ -21,6 +21,29 @@ config ERRATA_ANDES_CMO
 
 	  If you don't know what to do here, say "Y".
 
+config ERRATA_MIPS
+	bool "MIPS errata"
+	depends on RISCV_ALTERNATIVE
+	help
+	  All MIPS errata Kconfig depend on this Kconfig. Disabling
+	  this Kconfig will disable all MIPS errata. Please say "Y"
+	  here if your platform uses MIPS CPU cores.
+
+	  Otherwise, please say "N" here to avoid unnecessary overhead.
+
+config ERRATA_MIPS_P8700_PAUSE_OPCODE
+	bool "Fix the PAUSE Opcode for MIPS P8700"
+	depends on ERRATA_MIPS && 64BIT
+	default n
+	help
+	   The RISCV MIPS P8700 uses a different opcode for PAUSE.
+	   It is a 'hint' encoding of the SLLI instruction,
+	   with rd=0, rs1=0 and imm=5. It will behave as a NOP
+	   instruction if no additional behavior beyond that of
+	   SLLI is implemented.
+
+	   If you are not using the P8700 processor, say n.
+
 config ERRATA_SIFIVE
 	bool "SiFive errata"
 	depends on RISCV_ALTERNATIVE
diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile
index bc6c77ba837d2da4c98dabab18083d27f46629c7..02a7a3335b1d557933e04cd6d0cf7bf4260b8c40 100644
--- a/arch/riscv/errata/Makefile
+++ b/arch/riscv/errata/Makefile
@@ -13,5 +13,6 @@ endif
 endif
 
 obj-$(CONFIG_ERRATA_ANDES) += andes/
+obj-$(CONFIG_ERRATA_MIPS) += mips/
 obj-$(CONFIG_ERRATA_SIFIVE) += sifive/
 obj-$(CONFIG_ERRATA_THEAD) += thead/
diff --git a/arch/riscv/errata/mips/Makefile b/arch/riscv/errata/mips/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..6278c389b801ee6e54e808c80e6e236c026329c7
--- /dev/null
+++ b/arch/riscv/errata/mips/Makefile
@@ -0,0 +1,5 @@
+ifdef CONFIG_RISCV_ALTERNATIVE_EARLY
+CFLAGS_errata.o := -mcmodel=medany
+endif
+
+obj-y += errata.o
diff --git a/arch/riscv/errata/mips/errata.c b/arch/riscv/errata/mips/errata.c
new file mode 100644
index 0000000000000000000000000000000000000000..e984a8152208c34690f89d8101571b097485c360
--- /dev/null
+++ b/arch/riscv/errata/mips/errata.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 MIPS.
+ */
+
+#include <linux/memory.h>
+#include <linux/module.h>
+#include <asm/text-patching.h>
+#include <asm/alternative.h>
+#include <asm/errata_list.h>
+#include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/mips.h>
+
+static inline bool errata_probe_pause(void)
+{
+	if (!IS_ENABLED(CONFIG_ERRATA_MIPS_P8700_PAUSE_OPCODE))
+		return false;
+
+	if (!riscv_isa_vendor_extension_available(MIPS_VENDOR_ID, XMIPSEXECTL))
+		return false;
+
+	return true;
+}
+
+static u32 mips_errata_probe(void)
+{
+	u32 cpu_req_errata = 0;
+
+	if (errata_probe_pause())
+		cpu_req_errata |= BIT(ERRATA_MIPS_P8700_PAUSE_OPCODE);
+
+	return cpu_req_errata;
+}
+
+void mips_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
+			    unsigned long archid, unsigned long impid,
+			    unsigned int stage)
+{
+	struct alt_entry *alt;
+	u32 cpu_req_errata = mips_errata_probe();
+	u32 tmp;
+
+	BUILD_BUG_ON(ERRATA_MIPS_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
+	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+		return;
+
+	for (alt = begin; alt < end; alt++) {
+		if (alt->vendor_id != MIPS_VENDOR_ID)
+			continue;
+
+		if (alt->patch_id >= ERRATA_MIPS_NUMBER) {
+			WARN(1, "MIPS errata id:%d not in kernel errata list\n",
+			     alt->patch_id);
+			continue;
+		}
+
+		tmp = (1U << alt->patch_id);
+		if (cpu_req_errata && tmp) {
+			mutex_lock(&text_mutex);
+			patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
+					  alt->alt_len);
+			mutex_unlock(&text_mutex);
+		}
+	}
+}
diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
index 0e95539ba451ba55abb15ee4a26b6125c9d0261a..82eabf9a117a864a473a3c916b67bd91d1309671 100644
--- a/arch/riscv/include/asm/alternative.h
+++ b/arch/riscv/include/asm/alternative.h
@@ -48,6 +48,9 @@ struct alt_entry {
 void andes_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 			     unsigned long archid, unsigned long impid,
 			     unsigned int stage);
+void mips_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
+			      unsigned long archid, unsigned long impid,
+			      unsigned int stage);
 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 			      unsigned long archid, unsigned long impid,
 			      unsigned int stage);
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h
index 0b749e7102162477432f7cf9a34768fbdf2e8cc7..80bd52363c68690f33bfd54e0cc40399cd60b57b 100644
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
@@ -14,6 +14,7 @@
 #include <asm/insn-def.h>
 #include <asm/cpufeature-macros.h>
 #include <asm/processor.h>
+#include <asm/errata_list.h>
 
 #define __arch_xchg_masked(sc_sfx, swap_sfx, prepend, sc_append,		\
 			   swap_append, r, p, n)				\
@@ -438,7 +439,7 @@ static __always_inline void __cmpwait(volatile void *ptr,
 	return;
 
 no_zawrs:
-	asm volatile(RISCV_PAUSE : : : "memory");
+	ALT_RISCV_PAUSE();
 }
 
 #define __cmpwait_relaxed(ptr, val) \
diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
index a2481f14b68d56b3435d160793699002a45472eb..6694b5ccdcf85cfe7e767ea4de981b34f2b17b04 100644
--- a/arch/riscv/include/asm/errata_list.h
+++ b/arch/riscv/include/asm/errata_list.h
@@ -5,12 +5,12 @@
 #ifndef ASM_ERRATA_LIST_H
 #define ASM_ERRATA_LIST_H
 
-#include <asm/alternative.h>
 #include <asm/csr.h>
 #include <asm/insn-def.h>
 #include <asm/hwcap.h>
 #include <asm/vendorid_list.h>
 #include <asm/errata_list_vendors.h>
+#include <asm/vendor_extensions/mips.h>
 
 #ifdef __ASSEMBLER__
 
@@ -42,6 +42,17 @@ asm(ALTERNATIVE("sfence.vma %0, %1", "sfence.vma", SIFIVE_VENDOR_ID,	\
 		ERRATA_SIFIVE_CIP_1200, CONFIG_ERRATA_SIFIVE_CIP_1200)	\
 		: : "r" (addr), "r" (asid) : "memory")
 
+#define ALT_RISCV_PAUSE()					\
+asm(ALTERNATIVE(	\
+		RISCV_PAUSE, /* Original RISC‑V pause insn */	\
+		MIPS_PAUSE, /* Replacement for MIPS P8700 */	\
+		MIPS_VENDOR_ID, /* Vendor ID to match */	\
+		ERRATA_MIPS_P8700_PAUSE_OPCODE, /* patch_id */	\
+		CONFIG_ERRATA_MIPS_P8700_PAUSE_OPCODE)	\
+	: /* no outputs */	\
+	: /* no inputs */	\
+	: "memory")
+
 /*
  * _val is marked as "will be overwritten", so need to set it to 0
  * in the default case.
diff --git a/arch/riscv/include/asm/errata_list_vendors.h b/arch/riscv/include/asm/errata_list_vendors.h
index a7473cb8874d62b26ae5c6a2c06144b922e24efe..9739a70ed69984ba4fc5f51a4967a58c4b02613a 100644
--- a/arch/riscv/include/asm/errata_list_vendors.h
+++ b/arch/riscv/include/asm/errata_list_vendors.h
@@ -22,4 +22,9 @@
 #define	ERRATA_THEAD_NUMBER 4
 #endif
 
+#ifdef CONFIG_ERRATA_MIPS
+#define	ERRATA_MIPS_P8700_PAUSE_OPCODE 0
+#define	ERRATA_MIPS_NUMBER 1
+#endif
+
 #endif
diff --git a/arch/riscv/include/asm/vdso/processor.h b/arch/riscv/include/asm/vdso/processor.h
index 98fb44336c055f1c60899cb25c99f2416184c466..c42f95dc8811d8a949898f7338151dcc4e987372 100644
--- a/arch/riscv/include/asm/vdso/processor.h
+++ b/arch/riscv/include/asm/vdso/processor.h
@@ -5,6 +5,7 @@
 #ifndef __ASSEMBLER__
 
 #include <asm/barrier.h>
+#include <asm/errata_list.h>
 #include <asm/insn-def.h>
 
 static inline void cpu_relax(void)
@@ -19,7 +20,7 @@ static inline void cpu_relax(void)
 	 * Reduce instruction retirement.
 	 * This assumes the PC changes.
 	 */
-	__asm__ __volatile__ (RISCV_PAUSE);
+	ALT_RISCV_PAUSE();
 	barrier();
 }
 
diff --git a/arch/riscv/include/asm/vendorid_list.h b/arch/riscv/include/asm/vendorid_list.h
index a5150cdf34d87f01baf6d3ef843bc2d6d8d54095..3b09874d7a6dfb8f8aa45b0be41c20711d539e78 100644
--- a/arch/riscv/include/asm/vendorid_list.h
+++ b/arch/riscv/include/asm/vendorid_list.h
@@ -9,5 +9,6 @@
 #define MICROCHIP_VENDOR_ID	0x029
 #define SIFIVE_VENDOR_ID	0x489
 #define THEAD_VENDOR_ID		0x5b7
+#define MIPS_VENDOR_ID		0x722
 
 #endif
diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index 7eb3cb1215c62130c63a72fc650cddff6bae62af..7642704c7f1841f67fc23738063f22b4ecf58194 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -47,6 +47,11 @@ static void riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info
 		cpu_mfr_info->patch_func = andes_errata_patch_func;
 		break;
 #endif
+#ifdef CONFIG_ERRATA_MIPS
+	case MIPS_VENDOR_ID:
+		cpu_mfr_info->patch_func = mips_errata_patch_func;
+		break;
+#endif
 #ifdef CONFIG_ERRATA_SIFIVE
 	case SIFIVE_VENDOR_ID:
 		cpu_mfr_info->patch_func = sifive_errata_patch_func;
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 8d0374d7ce8ed72320f58e4cea212d0e2bce8fd4..3c2293bdfbccfde21c44497504c66fc4017f45a9 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -23,6 +23,7 @@
 #include <linux/kfence.h>
 #include <linux/execmem.h>
 
+#include <asm/alternative.h>
 #include <asm/fixmap.h>
 #include <asm/io.h>
 #include <asm/kasan.h>

-- 
2.34.1

Re: [PATCH v5 0/7] riscv: Add support for xmipsexectl

[Alexandre Ghiti]

Hi Aleksa,

On 7/24/25 17:23, Aleksa Paunovic via B4 Relay wrote:
> This patch series adds support for the xmipsexectl vendor extension.
> A new hardware probe key has also been added to allow userspace to probe for MIPS vendor extensions.
>
> Additionally, since the standard Zihintpause PAUSE instruction encoding is not supported on some MIPS CPUs,
> an errata was implemented for replacing this instruction with the xmipsexectl MIPS.PAUSE alternative encoding.
>
> Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
> ---
> Changes in v5:
> - Add MIPS.IHB and MIPS.EHB instructions
> - Rebase on alex-for-next
> - Address other smaller comments pointed out by Alexandre
> - Link to v4: https://lore.kernel.org/r/20250625-p8700-pause-v4-0-6c7dd7f85756@htecgroup.com
>
> This is a continuation of a previous series, which did not implement the full
> xmipsexectl vendor extension. The title was updated accordingly.
>
> Changes in v4:
> - Add support for the xmipsexectl vendor extension
> - Remove the ifdef/else from errata_list.h
> - Replace the ifdef/else with a hwprobe call in the userspace code.
>
> Link to v3:
> https://lore.kernel.org/linux-riscv/20250129131703.733098-1-arikalo@gmail.com/
>
> ---
> Aleksa Paunovic (6):
>        dt-bindings: riscv: Add xmipsexectl ISA extension description
>        riscv: Add xmipsexectl as a vendor extension
>        riscv: Add xmipsexectl instructions
>        riscv: hwprobe: Add MIPS vendor extension probing
>        riscv: hwprobe: Document MIPS xmipsexectl vendor extension
>        riscv: Add tools support for xmipsexectl
>
> Djordje Todorovic (1):
>        riscv: errata: Fix the PAUSE Opcode for MIPS P8700
>
>   Documentation/arch/riscv/hwprobe.rst               |  9 +++
>   .../devicetree/bindings/riscv/extensions.yaml      |  6 ++
>   arch/riscv/Kconfig.errata                          | 23 ++++++++
>   arch/riscv/Kconfig.vendor                          | 13 +++++
>   arch/riscv/errata/Makefile                         |  1 +
>   arch/riscv/errata/mips/Makefile                    |  5 ++
>   arch/riscv/errata/mips/errata.c                    | 67 ++++++++++++++++++++++
>   arch/riscv/include/asm/alternative.h               |  3 +
>   arch/riscv/include/asm/cmpxchg.h                   |  3 +-
>   arch/riscv/include/asm/errata_list.h               | 13 ++++-
>   arch/riscv/include/asm/errata_list_vendors.h       |  5 ++
>   arch/riscv/include/asm/hwprobe.h                   |  3 +-
>   arch/riscv/include/asm/vdso/processor.h            |  3 +-
>   arch/riscv/include/asm/vendor_extensions/mips.h    | 37 ++++++++++++
>   .../include/asm/vendor_extensions/mips_hwprobe.h   | 22 +++++++
>   arch/riscv/include/asm/vendorid_list.h             |  1 +
>   arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
>   arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +
>   arch/riscv/kernel/alternative.c                    |  5 ++
>   arch/riscv/kernel/sys_hwprobe.c                    |  4 ++
>   arch/riscv/kernel/vendor_extensions.c              | 10 ++++
>   arch/riscv/kernel/vendor_extensions/Makefile       |  2 +
>   arch/riscv/kernel/vendor_extensions/mips.c         | 22 +++++++
>   arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 23 ++++++++
>   arch/riscv/mm/init.c                               |  1 +
>   tools/arch/riscv/include/asm/vdso/processor.h      | 27 +++++----
>   26 files changed, 298 insertions(+), 14 deletions(-)
> ---
> base-commit: b6a4bae2f16162876842127d7507dad84e404f8f
> change-id: 20250424-p8700-pause-dcb649968e24
>
> Best regards,


Thanks for the v5, I'll take that for 6.17.

Thanks,

Alex

Re: [PATCH v5 0/7] riscv: Add support for xmipsexectl

[Aleksa Paunovic]

On 7/31/25 15:36, Alexandre Ghiti wrote:

> Hi Aleksa,
>
> On 7/24/25 17:23, Aleksa Paunovic via B4 Relay wrote:
>> This patch series adds support for the xmipsexectl vendor extension.
>> A new hardware probe key has also been added to allow userspace to probe for MIPS vendor extensions.
>>
>> Additionally, since the standard Zihintpause PAUSE instruction encoding is not supported on some MIPS CPUs,
>> an errata was implemented for replacing this instruction with the xmipsexectl MIPS.PAUSE alternative encoding.
>>
>> Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
>> ---
>> Changes in v5:
>> - Add MIPS.IHB and MIPS.EHB instructions
>> - Rebase on alex-for-next
>> - Address other smaller comments pointed out by Alexandre
>> - Link to v4: https://lore.kernel.org/r/20250625-p8700-pause-v4-0-6c7dd7f85756@htecgroup.com
>>
>> This is a continuation of a previous series, which did not implement the full
>> xmipsexectl vendor extension. The title was updated accordingly.
>>
>> Changes in v4:
>> - Add support for the xmipsexectl vendor extension
>> - Remove the ifdef/else from errata_list.h
>> - Replace the ifdef/else with a hwprobe call in the userspace code.
>>
>> Link to v3:
>> https://lore.kernel.org/linux-riscv/20250129131703.733098-1-arikalo@gmail.com/
>>
>> ---
>> Aleksa Paunovic (6):
>>        dt-bindings: riscv: Add xmipsexectl ISA extension description
>>        riscv: Add xmipsexectl as a vendor extension
>>        riscv: Add xmipsexectl instructions
>>        riscv: hwprobe: Add MIPS vendor extension probing
>>        riscv: hwprobe: Document MIPS xmipsexectl vendor extension
>>        riscv: Add tools support for xmipsexectl
>>
>> Djordje Todorovic (1):
>>        riscv: errata: Fix the PAUSE Opcode for MIPS P8700
>>
>>   Documentation/arch/riscv/hwprobe.rst               |  9 +++
>>   .../devicetree/bindings/riscv/extensions.yaml      |  6 ++
>>   arch/riscv/Kconfig.errata                          | 23 ++++++++
>>   arch/riscv/Kconfig.vendor                          | 13 +++++
>>   arch/riscv/errata/Makefile                         |  1 +
>>   arch/riscv/errata/mips/Makefile                    |  5 ++
>>   arch/riscv/errata/mips/errata.c                    | 67 ++++++++++++++++++++++
>>   arch/riscv/include/asm/alternative.h               |  3 +
>>   arch/riscv/include/asm/cmpxchg.h                   |  3 +-
>>   arch/riscv/include/asm/errata_list.h               | 13 ++++-
>>   arch/riscv/include/asm/errata_list_vendors.h       |  5 ++
>>   arch/riscv/include/asm/hwprobe.h                   |  3 +-
>>   arch/riscv/include/asm/vdso/processor.h            |  3 +-
>>   arch/riscv/include/asm/vendor_extensions/mips.h    | 37 ++++++++++++
>>   .../include/asm/vendor_extensions/mips_hwprobe.h   | 22 +++++++
>>   arch/riscv/include/asm/vendorid_list.h             |  1 +
>>   arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
>>   arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +
>>   arch/riscv/kernel/alternative.c                    |  5 ++
>>   arch/riscv/kernel/sys_hwprobe.c                    |  4 ++
>>   arch/riscv/kernel/vendor_extensions.c              | 10 ++++
>>   arch/riscv/kernel/vendor_extensions/Makefile       |  2 +
>>   arch/riscv/kernel/vendor_extensions/mips.c         | 22 +++++++
>>   arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 23 ++++++++
>>   arch/riscv/mm/init.c                               |  1 +
>>   tools/arch/riscv/include/asm/vdso/processor.h      | 27 +++++----
>>   26 files changed, 298 insertions(+), 14 deletions(-)
>> ---
>> base-commit: b6a4bae2f16162876842127d7507dad84e404f8f
>> change-id: 20250424-p8700-pause-dcb649968e24
>>
>> Best regards,
>
>
> Thanks for the v5, I'll take that for 6.17.

Hi Alexandre,

Thank you once again for taking the time to review the series.

Best regards,

Aleksa

>
> Thanks,
>
> Alex
>

Re: [PATCH v5 0/7] riscv: Add support for xmipsexectl

[patchwork-bot+linux-riscv]

Hello:

This series was applied to riscv/linux.git (for-next)
by Alexandre Ghiti <alexghiti@rivosinc.com>:

On Thu, 24 Jul 2025 17:23:24 +0200 you wrote:
> This patch series adds support for the xmipsexectl vendor extension.
> A new hardware probe key has also been added to allow userspace to probe for MIPS vendor extensions.
> 
> Additionally, since the standard Zihintpause PAUSE instruction encoding is not supported on some MIPS CPUs,
> an errata was implemented for replacing this instruction with the xmipsexectl MIPS.PAUSE alternative encoding.
> 
> Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
> 
> [...]

Here is the summary with links:
  - [v5,1/7] dt-bindings: riscv: Add xmipsexectl ISA extension description
    https://git.kernel.org/riscv/c/06d48c2c4f83
  - [v5,2/7] riscv: Add xmipsexectl as a vendor extension
    https://git.kernel.org/riscv/c/02b01dfaf4fa
  - [v5,3/7] riscv: Add xmipsexectl instructions
    https://git.kernel.org/riscv/c/d85071f97570
  - [v5,4/7] riscv: hwprobe: Add MIPS vendor extension probing
    https://git.kernel.org/riscv/c/20b80c735c05
  - [v5,5/7] riscv: hwprobe: Document MIPS xmipsexectl vendor extension
    https://git.kernel.org/riscv/c/c714fbc023df
  - [v5,6/7] riscv: Add tools support for xmipsexectl
    https://git.kernel.org/riscv/c/378afb53aab2
  - [v5,7/7] riscv: errata: Fix the PAUSE Opcode for MIPS P8700
    https://git.kernel.org/riscv/c/838218910ea3

You are awesome, thank you!
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