[PATCH v2 0/4] riscv: Separate vendor extensions from standard extensions

[PATCH v2 0/4] riscv: Separate vendor extensions from standard extensions

[Charlie Jenkins]

All extensions, both standard and vendor, live in one struct
"riscv_isa_ext". There is currently one vendor extension, xandespmu, but
it is likely that more vendor extensions will be added to the kernel in
the future. As more vendor extensions (and standard extensions) are
added, riscv_isa_ext will become more bloated with a mix of vendor and
standard extensions.

This also allows each vendor to be conditionally enabled through
Kconfig.

---
This has been split out from the previous series that contained the
addition of xtheadvector due to lack of reviews. The xtheadvector
support will be posted again separately from this.

The reviewed-bys on "riscv: Extend cpufeature.c to detect vendor extensions"
and "riscv: Introduce vendor variants of extension helpers" have been
dropped in this series. The majority of the code is the same in these
patches, but thead-specific code is swapped out with andes-specific
code. The changes are minimal, but I decided to drop the reviews in case
I inadvertently introduced issues.

The alternative patching code from "riscv: Introduce vendor variants of
extension helpers" has been migrated to "riscv: Extend cpufeature.c to
detect vendor extensions" such that the andes patching still works in
that patch.

I also fix a bug in this patch from the previous series that the Andes
extensions were not being properly enabled due to the manual alternative
patching not incrementing the id to be greater than
RISCV_VENDOR_EXT_ALTERNATIVES_BASE. 

To: Paul Walmsley <paul.walmsley@sifive.com>
To: Palmer Dabbelt <palmer@dabbelt.com>
To: Albert Ou <aou@eecs.berkeley.edu>
To: Conor Dooley <conor.dooley@microchip.com>
To: Evan Green <evan@rivosinc.com>
To: Andy Chiu <andy.chiu@sifive.com>
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>

---
Changes in v2:
- Fixed issue in riscv_fill_vendor_ext_list() that initalizion was only
  happening properly for the first vendor. Add is_initialized field to
  riscv_isa_vendor_ext_data_list to allow intialization to be tracked on
  a per-vendor basis.
- Link to v1: https://lore.kernel.org/r/20240515-support_vendor_extensions-v1-0-b05dd5ea7d8d@rivosinc.com

---
Charlie Jenkins (4):
      riscv: Extend cpufeature.c to detect vendor extensions
      riscv: Add vendor extensions to /proc/cpuinfo
      riscv: Introduce vendor variants of extension helpers
      riscv: cpufeature: Extract common elements from extension checking

 arch/riscv/Kconfig                               |   2 +
 arch/riscv/Kconfig.vendor                        |  19 ++++
 arch/riscv/errata/andes/errata.c                 |   3 +
 arch/riscv/errata/sifive/errata.c                |   3 +
 arch/riscv/errata/thead/errata.c                 |   3 +
 arch/riscv/include/asm/cpufeature.h              |  96 ++++++++++------
 arch/riscv/include/asm/hwcap.h                   |   1 -
 arch/riscv/include/asm/vendor_extensions.h       | 104 +++++++++++++++++
 arch/riscv/include/asm/vendor_extensions/andes.h |  19 ++++
 arch/riscv/kernel/Makefile                       |   2 +
 arch/riscv/kernel/cpu.c                          |  35 +++++-
 arch/riscv/kernel/cpufeature.c                   | 137 +++++++++++++++++------
 arch/riscv/kernel/vendor_extensions.c            |  56 +++++++++
 arch/riscv/kernel/vendor_extensions/Makefile     |   3 +
 arch/riscv/kernel/vendor_extensions/andes.c      |  18 +++
 drivers/perf/riscv_pmu_sbi.c                     |  11 +-
 16 files changed, 438 insertions(+), 74 deletions(-)
---
base-commit: c3f38fa61af77b49866b006939479069cd451173
change-id: 20240515-support_vendor_extensions-aa80120e4230
-- 
- Charlie

[PATCH v2 1/4] riscv: Extend cpufeature.c to detect vendor extensions

[Charlie Jenkins]

Instead of grouping all vendor extensions into the same riscv_isa_ext
that standard instructions use, create a struct
"riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
their vendor extensions independently of the standard extensions.
xandespmu is currently the only vendor extension so that is the only
extension that is affected by this change.

An additional benefit of this is that the extensions of each vendor can
be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
added to allow for that.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
 arch/riscv/Kconfig                               |   2 +
 arch/riscv/Kconfig.vendor                        |  19 ++++
 arch/riscv/errata/andes/errata.c                 |   3 +
 arch/riscv/errata/sifive/errata.c                |   3 +
 arch/riscv/errata/thead/errata.c                 |   3 +
 arch/riscv/include/asm/cpufeature.h              |  18 +++
 arch/riscv/include/asm/hwcap.h                   |   1 -
 arch/riscv/include/asm/vendor_extensions.h       |  49 ++++++++
 arch/riscv/include/asm/vendor_extensions/andes.h |  19 ++++
 arch/riscv/kernel/Makefile                       |   2 +
 arch/riscv/kernel/cpufeature.c                   | 137 +++++++++++++++++------
 arch/riscv/kernel/vendor_extensions.c            |  56 +++++++++
 arch/riscv/kernel/vendor_extensions/Makefile     |   3 +
 arch/riscv/kernel/vendor_extensions/andes.c      |  18 +++
 drivers/perf/riscv_pmu_sbi.c                     |  10 +-
 15 files changed, 306 insertions(+), 37 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0525ee2d63c7..4ae2bf4dd497 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -774,6 +774,8 @@ config RISCV_EFFICIENT_UNALIGNED_ACCESS
 
 endchoice
 
+source "arch/riscv/Kconfig.vendor"
+
 endmenu # "Platform type"
 
 menu "Kernel features"
diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
new file mode 100644
index 000000000000..6f1cdd32ed29
--- /dev/null
+++ b/arch/riscv/Kconfig.vendor
@@ -0,0 +1,19 @@
+menu "Vendor extensions"
+
+config RISCV_ISA_VENDOR_EXT
+	bool
+
+menu "Andes"
+config RISCV_ISA_VENDOR_EXT_ANDES
+	bool "Andes vendor extension support"
+	select RISCV_ISA_VENDOR_EXT
+	default y
+	help
+	  Say N here if you want to disable all Andes vendor extension
+	  support. This will cause any Andes vendor extensions that are
+	  requested by hardware probing to be ignored.
+
+	  If you don't know what to do here, say Y.
+endmenu
+
+endmenu
diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
index f2708a9494a1..fc1a34faa5f3 100644
--- a/arch/riscv/errata/andes/errata.c
+++ b/arch/riscv/errata/andes/errata.c
@@ -17,6 +17,7 @@
 #include <asm/processor.h>
 #include <asm/sbi.h>
 #include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
 
 #define ANDES_AX45MP_MARCHID		0x8000000000008a45UL
 #define ANDES_AX45MP_MIMPID		0x500UL
@@ -65,6 +66,8 @@ void __init_or_module andes_errata_patch_func(struct alt_entry *begin, struct al
 					      unsigned long archid, unsigned long impid,
 					      unsigned int stage)
 {
+	BUILD_BUG_ON(ERRATA_ANDES_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
 	if (stage == RISCV_ALTERNATIVES_BOOT)
 		errata_probe_iocp(stage, archid, impid);
 
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index 716cfedad3a2..cea3b96ade11 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -12,6 +12,7 @@
 #include <asm/alternative.h>
 #include <asm/vendorid_list.h>
 #include <asm/errata_list.h>
+#include <asm/vendor_extensions.h>
 
 struct errata_info_t {
 	char name[32];
@@ -96,6 +97,8 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 	u32 cpu_apply_errata = 0;
 	u32 tmp;
 
+	BUILD_BUG_ON(ERRATA_SIFIVE_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
 	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
 		return;
 
diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index bf6a0a6318ee..f5120e07c318 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -18,6 +18,7 @@
 #include <asm/io.h>
 #include <asm/patch.h>
 #include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
 
 #define CSR_TH_SXSTATUS		0x5c0
 #define SXSTATUS_MAEE		_AC(0x200000, UL)
@@ -166,6 +167,8 @@ void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 	u32 tmp;
 	void *oldptr, *altptr;
 
+	BUILD_BUG_ON(ERRATA_THEAD_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
 	for (alt = begin; alt < end; alt++) {
 		if (alt->vendor_id != THEAD_VENDOR_ID)
 			continue;
diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 347805446151..550d661dc78d 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -33,6 +33,24 @@ extern struct riscv_isainfo hart_isa[NR_CPUS];
 
 void riscv_user_isa_enable(void);
 
+#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {	\
+	.name = #_name,								\
+	.property = #_name,							\
+	.id = _id,								\
+	.subset_ext_ids = _subset_exts,						\
+	.subset_ext_size = _subset_exts_size					\
+}
+
+#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
+
+/* Used to declare pure "lasso" extension (Zk for instance) */
+#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
+	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
+
+/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
+#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
+	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
+
 #if defined(CONFIG_RISCV_MISALIGNED)
 bool check_unaligned_access_emulated_all_cpus(void);
 void unaligned_emulation_finish(void);
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index e17d0078a651..1f2d2599c655 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -80,7 +80,6 @@
 #define RISCV_ISA_EXT_ZFA		71
 #define RISCV_ISA_EXT_ZTSO		72
 #define RISCV_ISA_EXT_ZACAS		73
-#define RISCV_ISA_EXT_XANDESPMU		74
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
new file mode 100644
index 000000000000..5fca550fc1f6
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2024 Rivos, Inc
+ */
+
+#ifndef _ASM_VENDOR_EXTENSIONS_H
+#define _ASM_VENDOR_EXTENSIONS_H
+
+#include <asm/cpufeature.h>
+
+#include <linux/array_size.h>
+#include <linux/types.h>
+
+/*
+ * The extension keys of each vendor must be strictly less than this value.
+ */
+#define RISCV_ISA_VENDOR_EXT_MAX 32
+
+struct riscv_isavendorinfo {
+	DECLARE_BITMAP(isa, RISCV_ISA_VENDOR_EXT_MAX);
+};
+
+struct riscv_isa_vendor_ext_data_list {
+	bool is_initialized;
+	const size_t ext_data_count;
+	const struct riscv_isa_ext_data *ext_data;
+	struct riscv_isavendorinfo per_hart_isa_bitmap[NR_CPUS];
+	struct riscv_isavendorinfo all_harts_isa_bitmap;
+};
+
+extern struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[];
+
+extern const size_t riscv_isa_vendor_ext_list_size;
+
+/*
+ * The alternatives need some way of distinguishing between vendor extensions
+ * and errata. Incrementing all of the vendor extension keys so they are at
+ * least 0x8000 accomplishes that.
+ */
+#define RISCV_VENDOR_EXT_ALTERNATIVES_BASE	0x8000
+
+#define VENDOR_EXT_ALL_CPUS			-1
+
+bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
+#define riscv_isa_vendor_extension_available(vendor, ext)	\
+	__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
+					       RISCV_ISA_VENDOR_EXT_##ext)
+
+#endif /* _ASM_VENDOR_EXTENSIONS_H */
diff --git a/arch/riscv/include/asm/vendor_extensions/andes.h b/arch/riscv/include/asm/vendor_extensions/andes.h
new file mode 100644
index 000000000000..7bb2fc43438f
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/andes.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
+
+#include <asm/vendor_extensions.h>
+
+#include <linux/types.h>
+
+#define RISCV_ISA_VENDOR_EXT_XANDESPMU		0
+
+/*
+ * Extension keys should be strictly less than max.
+ * It is safe to increment this when necessary.
+ */
+#define RISCV_ISA_VENDOR_EXT_MAX_ANDES			32
+
+extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes;
+
+#endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 5b243d46f4b1..b0aea202273d 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -58,6 +58,8 @@ obj-y	+= riscv_ksyms.o
 obj-y	+= stacktrace.o
 obj-y	+= cacheinfo.o
 obj-y	+= patch.o
+obj-y	+= vendor_extensions.o
+obj-y	+= vendor_extensions/
 obj-y	+= probes/
 obj-y	+= tests/
 obj-$(CONFIG_MMU) += vdso.o vdso/
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 5ef48cb20ee1..f2c24820700b 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -24,6 +24,7 @@
 #include <asm/processor.h>
 #include <asm/sbi.h>
 #include <asm/vector.h>
+#include <asm/vendor_extensions.h>
 
 #define NUM_ALPHA_EXTS ('z' - 'a' + 1)
 
@@ -100,24 +101,6 @@ static bool riscv_isa_extension_check(int id)
 	return true;
 }
 
-#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {	\
-	.name = #_name,								\
-	.property = #_name,							\
-	.id = _id,								\
-	.subset_ext_ids = _subset_exts,						\
-	.subset_ext_size = _subset_exts_size					\
-}
-
-#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
-
-/* Used to declare pure "lasso" extension (Zk for instance) */
-#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
-	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
-
-/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
-#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
-	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
-
 static const unsigned int riscv_zk_bundled_exts[] = {
 	RISCV_ISA_EXT_ZBKB,
 	RISCV_ISA_EXT_ZBKC,
@@ -304,7 +287,6 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
 	__RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
 	__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
-	__RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_EXT_XANDESPMU),
 };
 
 const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
@@ -351,6 +333,21 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
 		bool ext_long = false, ext_err = false;
 
 		switch (*ext) {
+		case 'x':
+		case 'X':
+			if (acpi_disabled)
+				pr_warn_once("Vendor extensions are ignored in riscv,isa. Use riscv,isa-extensions instead.");
+			/*
+			 * To skip an extension, we find its end.
+			 * As multi-letter extensions must be split from other multi-letter
+			 * extensions with an "_", the end of a multi-letter extension will
+			 * either be the null character or the "_" at the start of the next
+			 * multi-letter extension.
+			 */
+			for (; *isa && *isa != '_'; ++isa)
+				;
+			ext_err = true;
+			break;
 		case 's':
 			/*
 			 * Workaround for invalid single-letter 's' & 'u' (QEMU).
@@ -366,8 +363,6 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
 			}
 			fallthrough;
 		case 'S':
-		case 'x':
-		case 'X':
 		case 'z':
 		case 'Z':
 			/*
@@ -574,6 +569,61 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap)
 		acpi_put_table((struct acpi_table_header *)rhct);
 }
 
+static void __init riscv_fill_cpu_vendor_ext(struct device_node *cpu_node, int cpu)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return;
+
+	for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
+		struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
+
+		for (int j = 0; j < ext_list->ext_data_count; j++) {
+			const struct riscv_isa_ext_data ext = ext_list->ext_data[j];
+			struct riscv_isavendorinfo *isavendorinfo = &ext_list->per_hart_isa_bitmap[cpu];
+
+			if (of_property_match_string(cpu_node, "riscv,isa-extensions",
+						     ext.property) < 0)
+				continue;
+
+			/*
+			 * Assume that subset extensions are all members of the
+			 * same vendor.
+			 */
+			if (ext.subset_ext_size)
+				for (int k = 0; k < ext.subset_ext_size; k++)
+					set_bit(ext.subset_ext_ids[k], isavendorinfo->isa);
+
+			set_bit(ext.id, isavendorinfo->isa);
+		}
+	}
+}
+
+/*
+ * Populate all_harts_isa_bitmap for each vendor with all of the extensions that
+ * are shared across CPUs for that vendor.
+ */
+static void __init riscv_fill_vendor_ext_list(int cpu)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return;
+
+	for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
+		struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
+
+		if (!ext_list->is_initialized) {
+			bitmap_copy(ext_list->all_harts_isa_bitmap.isa,
+				    ext_list->per_hart_isa_bitmap[cpu].isa,
+				    RISCV_ISA_VENDOR_EXT_MAX);
+			ext_list->is_initialized = true;
+		} else {
+			bitmap_and(ext_list->all_harts_isa_bitmap.isa,
+				   ext_list->all_harts_isa_bitmap.isa,
+				   ext_list->per_hart_isa_bitmap[cpu].isa,
+				   RISCV_ISA_VENDOR_EXT_MAX);
+		}
+	}
+}
+
 static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
 {
 	unsigned int cpu;
@@ -617,6 +667,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
 			}
 		}
 
+		riscv_fill_cpu_vendor_ext(cpu_node, cpu);
+
 		of_node_put(cpu_node);
 
 		/*
@@ -632,6 +684,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
 			bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
 		else
 			bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
+
+		riscv_fill_vendor_ext_list(cpu);
 	}
 
 	if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX))
@@ -768,28 +822,45 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
 {
 	struct alt_entry *alt;
 	void *oldptr, *altptr;
-	u16 id, value;
+	u16 id, value, vendor;
 
 	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
 		return;
 
 	for (alt = begin; alt < end; alt++) {
-		if (alt->vendor_id != 0)
-			continue;
-
 		id = PATCH_ID_CPUFEATURE_ID(alt->patch_id);
+		vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id);
 
-		if (id >= RISCV_ISA_EXT_MAX) {
-			WARN(1, "This extension id:%d is not in ISA extension list", id);
-			continue;
-		}
+		/*
+		 * Any alternative with a patch_id that is less than
+		 * RISCV_ISA_EXT_MAX is interpreted as a standard extension.
+		 *
+		 * Any alternative with patch_id that is greater than or equal
+		 * to RISCV_VENDOR_EXT_ALTERNATIVES_BASE is interpreted as a
+		 * vendor extension.
+		 */
+		if (id < RISCV_ISA_EXT_MAX) {
+			/*
+			 * This patch should be treated as errata so skip
+			 * processing here.
+			 */
+			if (alt->vendor_id != 0)
+				continue;
 
-		if (!__riscv_isa_extension_available(NULL, id))
-			continue;
+			if (!__riscv_isa_extension_available(NULL, id))
+				continue;
 
-		value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
-		if (!riscv_cpufeature_patch_check(id, value))
+			value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
+			if (!riscv_cpufeature_patch_check(id, value))
+				continue;
+		} else if (id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE) {
+			if (!__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor,
+								    id - RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
+				continue;
+		} else {
+			WARN(1, "This extension id:%d is not in ISA extension list", id);
 			continue;
+		}
 
 		oldptr = ALT_OLD_PTR(alt);
 		altptr = ALT_ALT_PTR(alt);
diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
new file mode 100644
index 000000000000..b6c1e7b5d34b
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2024 Rivos, Inc
+ */
+
+#include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/andes.h>
+
+#include <linux/array_size.h>
+#include <linux/types.h>
+
+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
+};
+
+const size_t riscv_isa_vendor_ext_list_size = ARRAY_SIZE(riscv_isa_vendor_ext_list);
+
+/**
+ * __riscv_isa_vendor_extension_available() - Check whether given vendor
+ * extension is available or not.
+ *
+ * @cpu: check if extension is available on this cpu
+ * @vendor: vendor that the extension is a member of
+ * @bit: bit position of the desired extension
+ * Return: true or false
+ *
+ * NOTE: When cpu is -1, will check if extension is available on all cpus
+ */
+bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit)
+{
+	struct riscv_isavendorinfo *bmap;
+	struct riscv_isavendorinfo *cpu_bmap;
+
+	switch (vendor) {
+	#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
+	case ANDES_VENDOR_ID:
+		bmap = &riscv_isa_vendor_ext_list_andes.all_harts_isa_bitmap;
+		cpu_bmap = &riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap[cpu];
+		break;
+	#endif
+	default:
+		return false;
+	}
+
+	if (cpu != -1)
+		bmap = &cpu_bmap[cpu];
+
+	if (bit >= RISCV_ISA_VENDOR_EXT_MAX)
+		return false;
+
+	return test_bit(bit, bmap->isa) ? true : false;
+}
+EXPORT_SYMBOL_GPL(__riscv_isa_vendor_extension_available);
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
new file mode 100644
index 000000000000..6a61aed944f1
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
diff --git a/arch/riscv/kernel/vendor_extensions/andes.c b/arch/riscv/kernel/vendor_extensions/andes.c
new file mode 100644
index 000000000000..ec688c88456a
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/andes.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/cpufeature.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/andes.h>
+
+#include <linux/array_size.h>
+#include <linux/types.h>
+
+/* All Andes vendor extensions supported in Linux */
+const struct riscv_isa_ext_data riscv_isa_vendor_ext_andes[] = {
+	__RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_VENDOR_EXT_XANDESPMU),
+};
+
+struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes = {
+	.ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_andes),
+	.ext_data = riscv_isa_vendor_ext_andes,
+};
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index a2e4005e1fd0..02719e0c6368 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -24,6 +24,8 @@
 #include <asm/errata_list.h>
 #include <asm/sbi.h>
 #include <asm/cpufeature.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/andes.h>
 
 #define ALT_SBI_PMU_OVERFLOW(__ovl)					\
 asm volatile(ALTERNATIVE_2(						\
@@ -32,7 +34,8 @@ asm volatile(ALTERNATIVE_2(						\
 		THEAD_VENDOR_ID, ERRATA_THEAD_PMU,			\
 		CONFIG_ERRATA_THEAD_PMU,				\
 	"csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF),			\
-		0, RISCV_ISA_EXT_XANDESPMU,				\
+		ANDES_VENDOR_ID,					\
+		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
 		CONFIG_ANDES_CUSTOM_PMU)				\
 	: "=r" (__ovl) :						\
 	: "memory")
@@ -41,7 +44,8 @@ asm volatile(ALTERNATIVE_2(						\
 asm volatile(ALTERNATIVE(						\
 	"csrc " __stringify(CSR_IP) ", %0\n\t",				\
 	"csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t",			\
-		0, RISCV_ISA_EXT_XANDESPMU,				\
+		ANDES_VENDOR_ID,					\
+		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
 		CONFIG_ANDES_CUSTOM_PMU)				\
 	: : "r"(__irq_mask)						\
 	: "memory")
@@ -1060,7 +1064,7 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
 		   riscv_cached_mimpid(0) == 0) {
 		riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
 		riscv_pmu_use_irq = true;
-	} else if (riscv_isa_extension_available(NULL, XANDESPMU) &&
+	} else if (riscv_isa_vendor_extension_available(ANDES_VENDOR_ID, XANDESPMU) &&
 		   IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
 		riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
 		riscv_pmu_use_irq = true;

-- 
2.44.0

Re: [PATCH v2 1/4] riscv: Extend cpufeature.c to detect vendor extensions

[Conor Dooley]

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On Sun, Jun 09, 2024 at 09:34:14PM -0700, Charlie Jenkins wrote:
> Instead of grouping all vendor extensions into the same riscv_isa_ext
> that standard instructions use, create a struct
> "riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
> their vendor extensions independently of the standard extensions.
> xandespmu is currently the only vendor extension so that is the only
> extension that is affected by this change.
> 
> An additional benefit of this is that the extensions of each vendor can
> be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
> added to allow for that.
> 
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v2 1/4] riscv: Extend cpufeature.c to detect vendor extensions

[Andy Chiu]

On Mon, Jun 10, 2024 at 12:34 PM Charlie Jenkins <charlie@rivosinc.com> wrote:
>
> Instead of grouping all vendor extensions into the same riscv_isa_ext
> that standard instructions use, create a struct
> "riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
> their vendor extensions independently of the standard extensions.
> xandespmu is currently the only vendor extension so that is the only
> extension that is affected by this change.
>
> An additional benefit of this is that the extensions of each vendor can
> be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
> added to allow for that.
>
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>

Reviewed-by: Andy Chiu <andy.chiu@sifive.com>

> ---
>  arch/riscv/Kconfig                               |   2 +
>  arch/riscv/Kconfig.vendor                        |  19 ++++
>  arch/riscv/errata/andes/errata.c                 |   3 +
>  arch/riscv/errata/sifive/errata.c                |   3 +
>  arch/riscv/errata/thead/errata.c                 |   3 +
>  arch/riscv/include/asm/cpufeature.h              |  18 +++
>  arch/riscv/include/asm/hwcap.h                   |   1 -
>  arch/riscv/include/asm/vendor_extensions.h       |  49 ++++++++
>  arch/riscv/include/asm/vendor_extensions/andes.h |  19 ++++
>  arch/riscv/kernel/Makefile                       |   2 +
>  arch/riscv/kernel/cpufeature.c                   | 137 +++++++++++++++++------
>  arch/riscv/kernel/vendor_extensions.c            |  56 +++++++++
>  arch/riscv/kernel/vendor_extensions/Makefile     |   3 +
>  arch/riscv/kernel/vendor_extensions/andes.c      |  18 +++
>  drivers/perf/riscv_pmu_sbi.c                     |  10 +-
>  15 files changed, 306 insertions(+), 37 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0525ee2d63c7..4ae2bf4dd497 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -774,6 +774,8 @@ config RISCV_EFFICIENT_UNALIGNED_ACCESS
>
>  endchoice
>
> +source "arch/riscv/Kconfig.vendor"
> +
>  endmenu # "Platform type"
>
>  menu "Kernel features"
> diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
> new file mode 100644
> index 000000000000..6f1cdd32ed29
> --- /dev/null
> +++ b/arch/riscv/Kconfig.vendor
> @@ -0,0 +1,19 @@
> +menu "Vendor extensions"
> +
> +config RISCV_ISA_VENDOR_EXT
> +       bool
> +
> +menu "Andes"
> +config RISCV_ISA_VENDOR_EXT_ANDES
> +       bool "Andes vendor extension support"
> +       select RISCV_ISA_VENDOR_EXT
> +       default y
> +       help
> +         Say N here if you want to disable all Andes vendor extension
> +         support. This will cause any Andes vendor extensions that are
> +         requested by hardware probing to be ignored.
> +
> +         If you don't know what to do here, say Y.
> +endmenu
> +
> +endmenu
> diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
> index f2708a9494a1..fc1a34faa5f3 100644
> --- a/arch/riscv/errata/andes/errata.c
> +++ b/arch/riscv/errata/andes/errata.c
> @@ -17,6 +17,7 @@
>  #include <asm/processor.h>
>  #include <asm/sbi.h>
>  #include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
>
>  #define ANDES_AX45MP_MARCHID           0x8000000000008a45UL
>  #define ANDES_AX45MP_MIMPID            0x500UL
> @@ -65,6 +66,8 @@ void __init_or_module andes_errata_patch_func(struct alt_entry *begin, struct al
>                                               unsigned long archid, unsigned long impid,
>                                               unsigned int stage)
>  {
> +       BUILD_BUG_ON(ERRATA_ANDES_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>         if (stage == RISCV_ALTERNATIVES_BOOT)
>                 errata_probe_iocp(stage, archid, impid);
>
> diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
> index 716cfedad3a2..cea3b96ade11 100644
> --- a/arch/riscv/errata/sifive/errata.c
> +++ b/arch/riscv/errata/sifive/errata.c
> @@ -12,6 +12,7 @@
>  #include <asm/alternative.h>
>  #include <asm/vendorid_list.h>
>  #include <asm/errata_list.h>
> +#include <asm/vendor_extensions.h>
>
>  struct errata_info_t {
>         char name[32];
> @@ -96,6 +97,8 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>         u32 cpu_apply_errata = 0;
>         u32 tmp;
>
> +       BUILD_BUG_ON(ERRATA_SIFIVE_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>         if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
>                 return;
>
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index bf6a0a6318ee..f5120e07c318 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -18,6 +18,7 @@
>  #include <asm/io.h>
>  #include <asm/patch.h>
>  #include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
>
>  #define CSR_TH_SXSTATUS                0x5c0
>  #define SXSTATUS_MAEE          _AC(0x200000, UL)
> @@ -166,6 +167,8 @@ void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>         u32 tmp;
>         void *oldptr, *altptr;
>
> +       BUILD_BUG_ON(ERRATA_THEAD_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>         for (alt = begin; alt < end; alt++) {
>                 if (alt->vendor_id != THEAD_VENDOR_ID)
>                         continue;
> diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
> index 347805446151..550d661dc78d 100644
> --- a/arch/riscv/include/asm/cpufeature.h
> +++ b/arch/riscv/include/asm/cpufeature.h
> @@ -33,6 +33,24 @@ extern struct riscv_isainfo hart_isa[NR_CPUS];
>
>  void riscv_user_isa_enable(void);
>
> +#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {     \
> +       .name = #_name,                                                         \
> +       .property = #_name,                                                     \
> +       .id = _id,                                                              \
> +       .subset_ext_ids = _subset_exts,                                         \
> +       .subset_ext_size = _subset_exts_size                                    \
> +}
> +
> +#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
> +
> +/* Used to declare pure "lasso" extension (Zk for instance) */
> +#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
> +       _RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
> +
> +/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
> +#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
> +       _RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
> +
>  #if defined(CONFIG_RISCV_MISALIGNED)
>  bool check_unaligned_access_emulated_all_cpus(void);
>  void unaligned_emulation_finish(void);
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index e17d0078a651..1f2d2599c655 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -80,7 +80,6 @@
>  #define RISCV_ISA_EXT_ZFA              71
>  #define RISCV_ISA_EXT_ZTSO             72
>  #define RISCV_ISA_EXT_ZACAS            73
> -#define RISCV_ISA_EXT_XANDESPMU                74
>
>  #define RISCV_ISA_EXT_XLINUXENVCFG     127
>
> diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
> new file mode 100644
> index 000000000000..5fca550fc1f6
> --- /dev/null
> +++ b/arch/riscv/include/asm/vendor_extensions.h
> @@ -0,0 +1,49 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright 2024 Rivos, Inc
> + */
> +
> +#ifndef _ASM_VENDOR_EXTENSIONS_H
> +#define _ASM_VENDOR_EXTENSIONS_H
> +
> +#include <asm/cpufeature.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +/*
> + * The extension keys of each vendor must be strictly less than this value.
> + */
> +#define RISCV_ISA_VENDOR_EXT_MAX 32
> +
> +struct riscv_isavendorinfo {
> +       DECLARE_BITMAP(isa, RISCV_ISA_VENDOR_EXT_MAX);
> +};
> +
> +struct riscv_isa_vendor_ext_data_list {
> +       bool is_initialized;
> +       const size_t ext_data_count;
> +       const struct riscv_isa_ext_data *ext_data;
> +       struct riscv_isavendorinfo per_hart_isa_bitmap[NR_CPUS];
> +       struct riscv_isavendorinfo all_harts_isa_bitmap;
> +};
> +
> +extern struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[];
> +
> +extern const size_t riscv_isa_vendor_ext_list_size;
> +
> +/*
> + * The alternatives need some way of distinguishing between vendor extensions
> + * and errata. Incrementing all of the vendor extension keys so they are at
> + * least 0x8000 accomplishes that.
> + */
> +#define RISCV_VENDOR_EXT_ALTERNATIVES_BASE     0x8000
> +
> +#define VENDOR_EXT_ALL_CPUS                    -1
> +
> +bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
> +#define riscv_isa_vendor_extension_available(vendor, ext)      \
> +       __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
> +                                              RISCV_ISA_VENDOR_EXT_##ext)
> +
> +#endif /* _ASM_VENDOR_EXTENSIONS_H */
> diff --git a/arch/riscv/include/asm/vendor_extensions/andes.h b/arch/riscv/include/asm/vendor_extensions/andes.h
> new file mode 100644
> index 000000000000..7bb2fc43438f
> --- /dev/null
> +++ b/arch/riscv/include/asm/vendor_extensions/andes.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
> +#define _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
> +
> +#include <asm/vendor_extensions.h>
> +
> +#include <linux/types.h>
> +
> +#define RISCV_ISA_VENDOR_EXT_XANDESPMU         0
> +
> +/*
> + * Extension keys should be strictly less than max.
> + * It is safe to increment this when necessary.
> + */
> +#define RISCV_ISA_VENDOR_EXT_MAX_ANDES                 32
> +
> +extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes;
> +
> +#endif
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 5b243d46f4b1..b0aea202273d 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -58,6 +58,8 @@ obj-y += riscv_ksyms.o
>  obj-y  += stacktrace.o
>  obj-y  += cacheinfo.o
>  obj-y  += patch.o
> +obj-y  += vendor_extensions.o
> +obj-y  += vendor_extensions/
>  obj-y  += probes/
>  obj-y  += tests/
>  obj-$(CONFIG_MMU) += vdso.o vdso/
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 5ef48cb20ee1..f2c24820700b 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -24,6 +24,7 @@
>  #include <asm/processor.h>
>  #include <asm/sbi.h>
>  #include <asm/vector.h>
> +#include <asm/vendor_extensions.h>
>
>  #define NUM_ALPHA_EXTS ('z' - 'a' + 1)
>
> @@ -100,24 +101,6 @@ static bool riscv_isa_extension_check(int id)
>         return true;
>  }
>
> -#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {     \
> -       .name = #_name,                                                         \
> -       .property = #_name,                                                     \
> -       .id = _id,                                                              \
> -       .subset_ext_ids = _subset_exts,                                         \
> -       .subset_ext_size = _subset_exts_size                                    \
> -}
> -
> -#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
> -
> -/* Used to declare pure "lasso" extension (Zk for instance) */
> -#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
> -       _RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
> -
> -/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
> -#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
> -       _RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
> -
>  static const unsigned int riscv_zk_bundled_exts[] = {
>         RISCV_ISA_EXT_ZBKB,
>         RISCV_ISA_EXT_ZBKC,
> @@ -304,7 +287,6 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
>         __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
>         __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
>         __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
> -       __RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_EXT_XANDESPMU),
>  };
>
>  const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
> @@ -351,6 +333,21 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
>                 bool ext_long = false, ext_err = false;
>
>                 switch (*ext) {
> +               case 'x':
> +               case 'X':
> +                       if (acpi_disabled)
> +                               pr_warn_once("Vendor extensions are ignored in riscv,isa. Use riscv,isa-extensions instead.");
> +                       /*
> +                        * To skip an extension, we find its end.
> +                        * As multi-letter extensions must be split from other multi-letter
> +                        * extensions with an "_", the end of a multi-letter extension will
> +                        * either be the null character or the "_" at the start of the next
> +                        * multi-letter extension.
> +                        */
> +                       for (; *isa && *isa != '_'; ++isa)
> +                               ;
> +                       ext_err = true;
> +                       break;
>                 case 's':
>                         /*
>                          * Workaround for invalid single-letter 's' & 'u' (QEMU).
> @@ -366,8 +363,6 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
>                         }
>                         fallthrough;
>                 case 'S':
> -               case 'x':
> -               case 'X':
>                 case 'z':
>                 case 'Z':
>                         /*
> @@ -574,6 +569,61 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap)
>                 acpi_put_table((struct acpi_table_header *)rhct);
>  }
>
> +static void __init riscv_fill_cpu_vendor_ext(struct device_node *cpu_node, int cpu)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return;
> +
> +       for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
> +               struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
> +
> +               for (int j = 0; j < ext_list->ext_data_count; j++) {
> +                       const struct riscv_isa_ext_data ext = ext_list->ext_data[j];
> +                       struct riscv_isavendorinfo *isavendorinfo = &ext_list->per_hart_isa_bitmap[cpu];
> +
> +                       if (of_property_match_string(cpu_node, "riscv,isa-extensions",
> +                                                    ext.property) < 0)
> +                               continue;
> +
> +                       /*
> +                        * Assume that subset extensions are all members of the
> +                        * same vendor.
> +                        */
> +                       if (ext.subset_ext_size)
> +                               for (int k = 0; k < ext.subset_ext_size; k++)
> +                                       set_bit(ext.subset_ext_ids[k], isavendorinfo->isa);
> +
> +                       set_bit(ext.id, isavendorinfo->isa);
> +               }
> +       }
> +}
> +
> +/*
> + * Populate all_harts_isa_bitmap for each vendor with all of the extensions that
> + * are shared across CPUs for that vendor.
> + */
> +static void __init riscv_fill_vendor_ext_list(int cpu)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return;
> +
> +       for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
> +               struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
> +
> +               if (!ext_list->is_initialized) {
> +                       bitmap_copy(ext_list->all_harts_isa_bitmap.isa,
> +                                   ext_list->per_hart_isa_bitmap[cpu].isa,
> +                                   RISCV_ISA_VENDOR_EXT_MAX);
> +                       ext_list->is_initialized = true;
> +               } else {
> +                       bitmap_and(ext_list->all_harts_isa_bitmap.isa,
> +                                  ext_list->all_harts_isa_bitmap.isa,
> +                                  ext_list->per_hart_isa_bitmap[cpu].isa,
> +                                  RISCV_ISA_VENDOR_EXT_MAX);
> +               }
> +       }
> +}
> +
>  static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>  {
>         unsigned int cpu;
> @@ -617,6 +667,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>                         }
>                 }
>
> +               riscv_fill_cpu_vendor_ext(cpu_node, cpu);
> +
>                 of_node_put(cpu_node);
>
>                 /*
> @@ -632,6 +684,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>                         bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
>                 else
>                         bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
> +
> +               riscv_fill_vendor_ext_list(cpu);
>         }
>
>         if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX))
> @@ -768,28 +822,45 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
>  {
>         struct alt_entry *alt;
>         void *oldptr, *altptr;
> -       u16 id, value;
> +       u16 id, value, vendor;
>
>         if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
>                 return;
>
>         for (alt = begin; alt < end; alt++) {
> -               if (alt->vendor_id != 0)
> -                       continue;
> -
>                 id = PATCH_ID_CPUFEATURE_ID(alt->patch_id);
> +               vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id);
>
> -               if (id >= RISCV_ISA_EXT_MAX) {
> -                       WARN(1, "This extension id:%d is not in ISA extension list", id);
> -                       continue;
> -               }
> +               /*
> +                * Any alternative with a patch_id that is less than
> +                * RISCV_ISA_EXT_MAX is interpreted as a standard extension.
> +                *
> +                * Any alternative with patch_id that is greater than or equal
> +                * to RISCV_VENDOR_EXT_ALTERNATIVES_BASE is interpreted as a
> +                * vendor extension.
> +                */
> +               if (id < RISCV_ISA_EXT_MAX) {
> +                       /*
> +                        * This patch should be treated as errata so skip
> +                        * processing here.
> +                        */
> +                       if (alt->vendor_id != 0)
> +                               continue;
>
> -               if (!__riscv_isa_extension_available(NULL, id))
> -                       continue;
> +                       if (!__riscv_isa_extension_available(NULL, id))
> +                               continue;
>
> -               value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
> -               if (!riscv_cpufeature_patch_check(id, value))
> +                       value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
> +                       if (!riscv_cpufeature_patch_check(id, value))
> +                               continue;
> +               } else if (id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE) {
> +                       if (!__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor,
> +                                                                   id - RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
> +                               continue;
> +               } else {
> +                       WARN(1, "This extension id:%d is not in ISA extension list", id);
>                         continue;
> +               }
>
>                 oldptr = ALT_OLD_PTR(alt);
>                 altptr = ALT_ALT_PTR(alt);
> diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
> new file mode 100644
> index 000000000000..b6c1e7b5d34b
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions.c
> @@ -0,0 +1,56 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2024 Rivos, Inc
> + */
> +
> +#include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +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
> +};
> +
> +const size_t riscv_isa_vendor_ext_list_size = ARRAY_SIZE(riscv_isa_vendor_ext_list);
> +
> +/**
> + * __riscv_isa_vendor_extension_available() - Check whether given vendor
> + * extension is available or not.
> + *
> + * @cpu: check if extension is available on this cpu
> + * @vendor: vendor that the extension is a member of
> + * @bit: bit position of the desired extension
> + * Return: true or false
> + *
> + * NOTE: When cpu is -1, will check if extension is available on all cpus
> + */
> +bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit)
> +{
> +       struct riscv_isavendorinfo *bmap;
> +       struct riscv_isavendorinfo *cpu_bmap;
> +
> +       switch (vendor) {
> +       #ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
> +       case ANDES_VENDOR_ID:
> +               bmap = &riscv_isa_vendor_ext_list_andes.all_harts_isa_bitmap;
> +               cpu_bmap = &riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap[cpu];
> +               break;
> +       #endif
> +       default:
> +               return false;
> +       }
> +
> +       if (cpu != -1)
> +               bmap = &cpu_bmap[cpu];
> +
> +       if (bit >= RISCV_ISA_VENDOR_EXT_MAX)
> +               return false;
> +
> +       return test_bit(bit, bmap->isa) ? true : false;
> +}
> +EXPORT_SYMBOL_GPL(__riscv_isa_vendor_extension_available);
> diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
> new file mode 100644
> index 000000000000..6a61aed944f1
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)       += andes.o
> diff --git a/arch/riscv/kernel/vendor_extensions/andes.c b/arch/riscv/kernel/vendor_extensions/andes.c
> new file mode 100644
> index 000000000000..ec688c88456a
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions/andes.c
> @@ -0,0 +1,18 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <asm/cpufeature.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +/* All Andes vendor extensions supported in Linux */
> +const struct riscv_isa_ext_data riscv_isa_vendor_ext_andes[] = {
> +       __RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_VENDOR_EXT_XANDESPMU),
> +};
> +
> +struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes = {
> +       .ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_andes),
> +       .ext_data = riscv_isa_vendor_ext_andes,
> +};
> diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
> index a2e4005e1fd0..02719e0c6368 100644
> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -24,6 +24,8 @@
>  #include <asm/errata_list.h>
>  #include <asm/sbi.h>
>  #include <asm/cpufeature.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
>
>  #define ALT_SBI_PMU_OVERFLOW(__ovl)                                    \
>  asm volatile(ALTERNATIVE_2(                                            \
> @@ -32,7 +34,8 @@ asm volatile(ALTERNATIVE_2(                                           \
>                 THEAD_VENDOR_ID, ERRATA_THEAD_PMU,                      \
>                 CONFIG_ERRATA_THEAD_PMU,                                \
>         "csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF),                  \
> -               0, RISCV_ISA_EXT_XANDESPMU,                             \
> +               ANDES_VENDOR_ID,                                        \
> +               RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
>                 CONFIG_ANDES_CUSTOM_PMU)                                \
>         : "=r" (__ovl) :                                                \
>         : "memory")
> @@ -41,7 +44,8 @@ asm volatile(ALTERNATIVE_2(                                           \
>  asm volatile(ALTERNATIVE(                                              \
>         "csrc " __stringify(CSR_IP) ", %0\n\t",                         \
>         "csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t",                 \
> -               0, RISCV_ISA_EXT_XANDESPMU,                             \
> +               ANDES_VENDOR_ID,                                        \
> +               RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
>                 CONFIG_ANDES_CUSTOM_PMU)                                \
>         : : "r"(__irq_mask)                                             \
>         : "memory")
> @@ -1060,7 +1064,7 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
>                    riscv_cached_mimpid(0) == 0) {
>                 riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
>                 riscv_pmu_use_irq = true;
> -       } else if (riscv_isa_extension_available(NULL, XANDESPMU) &&
> +       } else if (riscv_isa_vendor_extension_available(ANDES_VENDOR_ID, XANDESPMU) &&
>                    IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
>                 riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
>                 riscv_pmu_use_irq = true;
>
> --
> 2.44.0
>

Re: [PATCH v2 1/4] riscv: Extend cpufeature.c to detect vendor extensions

[Yu-Chien Peter Lin]

Hi Charlie,

On Sun, Jun 09, 2024 at 09:34:14PM -0700, Charlie Jenkins wrote:
> Instead of grouping all vendor extensions into the same riscv_isa_ext
> that standard instructions use, create a struct
> "riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
> their vendor extensions independently of the standard extensions.
> xandespmu is currently the only vendor extension so that is the only
> extension that is affected by this change.
> 
> An additional benefit of this is that the extensions of each vendor can
> be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
> added to allow for that.
> 
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> Reviewed-by: Andy Chiu <andy.chiu@sifive.com>

Andes PMU works as expected. Thanks for taking care of this.

Tested-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>

> ---
>  arch/riscv/Kconfig                               |   2 +
>  arch/riscv/Kconfig.vendor                        |  19 ++++
>  arch/riscv/errata/andes/errata.c                 |   3 +
>  arch/riscv/errata/sifive/errata.c                |   3 +
>  arch/riscv/errata/thead/errata.c                 |   3 +
>  arch/riscv/include/asm/cpufeature.h              |  18 +++
>  arch/riscv/include/asm/hwcap.h                   |   1 -
>  arch/riscv/include/asm/vendor_extensions.h       |  49 ++++++++
>  arch/riscv/include/asm/vendor_extensions/andes.h |  19 ++++
>  arch/riscv/kernel/Makefile                       |   2 +
>  arch/riscv/kernel/cpufeature.c                   | 137 +++++++++++++++++------
>  arch/riscv/kernel/vendor_extensions.c            |  56 +++++++++
>  arch/riscv/kernel/vendor_extensions/Makefile     |   3 +
>  arch/riscv/kernel/vendor_extensions/andes.c      |  18 +++
>  drivers/perf/riscv_pmu_sbi.c                     |  10 +-
>  15 files changed, 306 insertions(+), 37 deletions(-)
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0525ee2d63c7..4ae2bf4dd497 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -774,6 +774,8 @@ config RISCV_EFFICIENT_UNALIGNED_ACCESS
>  
>  endchoice
>  
> +source "arch/riscv/Kconfig.vendor"
> +
>  endmenu # "Platform type"
>  
>  menu "Kernel features"
> diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
> new file mode 100644
> index 000000000000..6f1cdd32ed29
> --- /dev/null
> +++ b/arch/riscv/Kconfig.vendor
> @@ -0,0 +1,19 @@
> +menu "Vendor extensions"
> +
> +config RISCV_ISA_VENDOR_EXT
> +	bool
> +
> +menu "Andes"
> +config RISCV_ISA_VENDOR_EXT_ANDES
> +	bool "Andes vendor extension support"
> +	select RISCV_ISA_VENDOR_EXT
> +	default y
> +	help
> +	  Say N here if you want to disable all Andes vendor extension
> +	  support. This will cause any Andes vendor extensions that are
> +	  requested by hardware probing to be ignored.
> +
> +	  If you don't know what to do here, say Y.
> +endmenu
> +
> +endmenu
> diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
> index f2708a9494a1..fc1a34faa5f3 100644
> --- a/arch/riscv/errata/andes/errata.c
> +++ b/arch/riscv/errata/andes/errata.c
> @@ -17,6 +17,7 @@
>  #include <asm/processor.h>
>  #include <asm/sbi.h>
>  #include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
>  
>  #define ANDES_AX45MP_MARCHID		0x8000000000008a45UL
>  #define ANDES_AX45MP_MIMPID		0x500UL
> @@ -65,6 +66,8 @@ void __init_or_module andes_errata_patch_func(struct alt_entry *begin, struct al
>  					      unsigned long archid, unsigned long impid,
>  					      unsigned int stage)
>  {
> +	BUILD_BUG_ON(ERRATA_ANDES_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>  	if (stage == RISCV_ALTERNATIVES_BOOT)
>  		errata_probe_iocp(stage, archid, impid);
>  
> diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
> index 716cfedad3a2..cea3b96ade11 100644
> --- a/arch/riscv/errata/sifive/errata.c
> +++ b/arch/riscv/errata/sifive/errata.c
> @@ -12,6 +12,7 @@
>  #include <asm/alternative.h>
>  #include <asm/vendorid_list.h>
>  #include <asm/errata_list.h>
> +#include <asm/vendor_extensions.h>
>  
>  struct errata_info_t {
>  	char name[32];
> @@ -96,6 +97,8 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>  	u32 cpu_apply_errata = 0;
>  	u32 tmp;
>  
> +	BUILD_BUG_ON(ERRATA_SIFIVE_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>  	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
>  		return;
>  
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index bf6a0a6318ee..f5120e07c318 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -18,6 +18,7 @@
>  #include <asm/io.h>
>  #include <asm/patch.h>
>  #include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
>  
>  #define CSR_TH_SXSTATUS		0x5c0
>  #define SXSTATUS_MAEE		_AC(0x200000, UL)
> @@ -166,6 +167,8 @@ void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
>  	u32 tmp;
>  	void *oldptr, *altptr;
>  
> +	BUILD_BUG_ON(ERRATA_THEAD_NUMBER >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
>  	for (alt = begin; alt < end; alt++) {
>  		if (alt->vendor_id != THEAD_VENDOR_ID)
>  			continue;
> diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
> index 347805446151..550d661dc78d 100644
> --- a/arch/riscv/include/asm/cpufeature.h
> +++ b/arch/riscv/include/asm/cpufeature.h
> @@ -33,6 +33,24 @@ extern struct riscv_isainfo hart_isa[NR_CPUS];
>  
>  void riscv_user_isa_enable(void);
>  
> +#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {	\
> +	.name = #_name,								\
> +	.property = #_name,							\
> +	.id = _id,								\
> +	.subset_ext_ids = _subset_exts,						\
> +	.subset_ext_size = _subset_exts_size					\
> +}
> +
> +#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
> +
> +/* Used to declare pure "lasso" extension (Zk for instance) */
> +#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
> +	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
> +
> +/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
> +#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
> +	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
> +
>  #if defined(CONFIG_RISCV_MISALIGNED)
>  bool check_unaligned_access_emulated_all_cpus(void);
>  void unaligned_emulation_finish(void);
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index e17d0078a651..1f2d2599c655 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -80,7 +80,6 @@
>  #define RISCV_ISA_EXT_ZFA		71
>  #define RISCV_ISA_EXT_ZTSO		72
>  #define RISCV_ISA_EXT_ZACAS		73
> -#define RISCV_ISA_EXT_XANDESPMU		74
>  
>  #define RISCV_ISA_EXT_XLINUXENVCFG	127
>  
> diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
> new file mode 100644
> index 000000000000..5fca550fc1f6
> --- /dev/null
> +++ b/arch/riscv/include/asm/vendor_extensions.h
> @@ -0,0 +1,49 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright 2024 Rivos, Inc
> + */
> +
> +#ifndef _ASM_VENDOR_EXTENSIONS_H
> +#define _ASM_VENDOR_EXTENSIONS_H
> +
> +#include <asm/cpufeature.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +/*
> + * The extension keys of each vendor must be strictly less than this value.
> + */
> +#define RISCV_ISA_VENDOR_EXT_MAX 32
> +
> +struct riscv_isavendorinfo {
> +	DECLARE_BITMAP(isa, RISCV_ISA_VENDOR_EXT_MAX);
> +};
> +
> +struct riscv_isa_vendor_ext_data_list {
> +	bool is_initialized;
> +	const size_t ext_data_count;
> +	const struct riscv_isa_ext_data *ext_data;
> +	struct riscv_isavendorinfo per_hart_isa_bitmap[NR_CPUS];
> +	struct riscv_isavendorinfo all_harts_isa_bitmap;
> +};
> +
> +extern struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[];
> +
> +extern const size_t riscv_isa_vendor_ext_list_size;
> +
> +/*
> + * The alternatives need some way of distinguishing between vendor extensions
> + * and errata. Incrementing all of the vendor extension keys so they are at
> + * least 0x8000 accomplishes that.
> + */
> +#define RISCV_VENDOR_EXT_ALTERNATIVES_BASE	0x8000
> +
> +#define VENDOR_EXT_ALL_CPUS			-1
> +
> +bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
> +#define riscv_isa_vendor_extension_available(vendor, ext)	\
> +	__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
> +					       RISCV_ISA_VENDOR_EXT_##ext)
> +
> +#endif /* _ASM_VENDOR_EXTENSIONS_H */
> diff --git a/arch/riscv/include/asm/vendor_extensions/andes.h b/arch/riscv/include/asm/vendor_extensions/andes.h
> new file mode 100644
> index 000000000000..7bb2fc43438f
> --- /dev/null
> +++ b/arch/riscv/include/asm/vendor_extensions/andes.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
> +#define _ASM_RISCV_VENDOR_EXTENSIONS_ANDES_H
> +
> +#include <asm/vendor_extensions.h>
> +
> +#include <linux/types.h>
> +
> +#define RISCV_ISA_VENDOR_EXT_XANDESPMU		0
> +
> +/*
> + * Extension keys should be strictly less than max.
> + * It is safe to increment this when necessary.
> + */
> +#define RISCV_ISA_VENDOR_EXT_MAX_ANDES			32
> +
> +extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes;
> +
> +#endif
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 5b243d46f4b1..b0aea202273d 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -58,6 +58,8 @@ obj-y	+= riscv_ksyms.o
>  obj-y	+= stacktrace.o
>  obj-y	+= cacheinfo.o
>  obj-y	+= patch.o
> +obj-y	+= vendor_extensions.o
> +obj-y	+= vendor_extensions/
>  obj-y	+= probes/
>  obj-y	+= tests/
>  obj-$(CONFIG_MMU) += vdso.o vdso/
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 5ef48cb20ee1..f2c24820700b 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -24,6 +24,7 @@
>  #include <asm/processor.h>
>  #include <asm/sbi.h>
>  #include <asm/vector.h>
> +#include <asm/vendor_extensions.h>
>  
>  #define NUM_ALPHA_EXTS ('z' - 'a' + 1)
>  
> @@ -100,24 +101,6 @@ static bool riscv_isa_extension_check(int id)
>  	return true;
>  }
>  
> -#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) {	\
> -	.name = #_name,								\
> -	.property = #_name,							\
> -	.id = _id,								\
> -	.subset_ext_ids = _subset_exts,						\
> -	.subset_ext_size = _subset_exts_size					\
> -}
> -
> -#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
> -
> -/* Used to declare pure "lasso" extension (Zk for instance) */
> -#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
> -	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
> -
> -/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
> -#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
> -	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
> -
>  static const unsigned int riscv_zk_bundled_exts[] = {
>  	RISCV_ISA_EXT_ZBKB,
>  	RISCV_ISA_EXT_ZBKC,
> @@ -304,7 +287,6 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
>  	__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
>  	__RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
>  	__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
> -	__RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_EXT_XANDESPMU),
>  };
>  
>  const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
> @@ -351,6 +333,21 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
>  		bool ext_long = false, ext_err = false;
>  
>  		switch (*ext) {
> +		case 'x':
> +		case 'X':
> +			if (acpi_disabled)
> +				pr_warn_once("Vendor extensions are ignored in riscv,isa. Use riscv,isa-extensions instead.");
> +			/*
> +			 * To skip an extension, we find its end.
> +			 * As multi-letter extensions must be split from other multi-letter
> +			 * extensions with an "_", the end of a multi-letter extension will
> +			 * either be the null character or the "_" at the start of the next
> +			 * multi-letter extension.
> +			 */
> +			for (; *isa && *isa != '_'; ++isa)
> +				;
> +			ext_err = true;
> +			break;
>  		case 's':
>  			/*
>  			 * Workaround for invalid single-letter 's' & 'u' (QEMU).
> @@ -366,8 +363,6 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
>  			}
>  			fallthrough;
>  		case 'S':
> -		case 'x':
> -		case 'X':
>  		case 'z':
>  		case 'Z':
>  			/*
> @@ -574,6 +569,61 @@ static void __init riscv_fill_hwcap_from_isa_string(unsigned long *isa2hwcap)
>  		acpi_put_table((struct acpi_table_header *)rhct);
>  }
>  
> +static void __init riscv_fill_cpu_vendor_ext(struct device_node *cpu_node, int cpu)
> +{
> +	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +		return;
> +
> +	for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
> +		struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
> +
> +		for (int j = 0; j < ext_list->ext_data_count; j++) {
> +			const struct riscv_isa_ext_data ext = ext_list->ext_data[j];
> +			struct riscv_isavendorinfo *isavendorinfo = &ext_list->per_hart_isa_bitmap[cpu];
> +
> +			if (of_property_match_string(cpu_node, "riscv,isa-extensions",
> +						     ext.property) < 0)
> +				continue;
> +
> +			/*
> +			 * Assume that subset extensions are all members of the
> +			 * same vendor.
> +			 */
> +			if (ext.subset_ext_size)
> +				for (int k = 0; k < ext.subset_ext_size; k++)
> +					set_bit(ext.subset_ext_ids[k], isavendorinfo->isa);
> +
> +			set_bit(ext.id, isavendorinfo->isa);
> +		}
> +	}
> +}
> +
> +/*
> + * Populate all_harts_isa_bitmap for each vendor with all of the extensions that
> + * are shared across CPUs for that vendor.
> + */
> +static void __init riscv_fill_vendor_ext_list(int cpu)
> +{
> +	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +		return;
> +
> +	for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
> +		struct riscv_isa_vendor_ext_data_list *ext_list = riscv_isa_vendor_ext_list[i];
> +
> +		if (!ext_list->is_initialized) {
> +			bitmap_copy(ext_list->all_harts_isa_bitmap.isa,
> +				    ext_list->per_hart_isa_bitmap[cpu].isa,
> +				    RISCV_ISA_VENDOR_EXT_MAX);
> +			ext_list->is_initialized = true;
> +		} else {
> +			bitmap_and(ext_list->all_harts_isa_bitmap.isa,
> +				   ext_list->all_harts_isa_bitmap.isa,
> +				   ext_list->per_hart_isa_bitmap[cpu].isa,
> +				   RISCV_ISA_VENDOR_EXT_MAX);
> +		}
> +	}
> +}
> +
>  static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>  {
>  	unsigned int cpu;
> @@ -617,6 +667,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>  			}
>  		}
>  
> +		riscv_fill_cpu_vendor_ext(cpu_node, cpu);
> +
>  		of_node_put(cpu_node);
>  
>  		/*
> @@ -632,6 +684,8 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
>  			bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
>  		else
>  			bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX);
> +
> +		riscv_fill_vendor_ext_list(cpu);
>  	}
>  
>  	if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX))
> @@ -768,28 +822,45 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
>  {
>  	struct alt_entry *alt;
>  	void *oldptr, *altptr;
> -	u16 id, value;
> +	u16 id, value, vendor;
>  
>  	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
>  		return;
>  
>  	for (alt = begin; alt < end; alt++) {
> -		if (alt->vendor_id != 0)
> -			continue;
> -
>  		id = PATCH_ID_CPUFEATURE_ID(alt->patch_id);
> +		vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id);
>  
> -		if (id >= RISCV_ISA_EXT_MAX) {
> -			WARN(1, "This extension id:%d is not in ISA extension list", id);
> -			continue;
> -		}
> +		/*
> +		 * Any alternative with a patch_id that is less than
> +		 * RISCV_ISA_EXT_MAX is interpreted as a standard extension.
> +		 *
> +		 * Any alternative with patch_id that is greater than or equal
> +		 * to RISCV_VENDOR_EXT_ALTERNATIVES_BASE is interpreted as a
> +		 * vendor extension.
> +		 */
> +		if (id < RISCV_ISA_EXT_MAX) {
> +			/*
> +			 * This patch should be treated as errata so skip
> +			 * processing here.
> +			 */
> +			if (alt->vendor_id != 0)
> +				continue;
>  
> -		if (!__riscv_isa_extension_available(NULL, id))
> -			continue;
> +			if (!__riscv_isa_extension_available(NULL, id))
> +				continue;
>  
> -		value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
> -		if (!riscv_cpufeature_patch_check(id, value))
> +			value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
> +			if (!riscv_cpufeature_patch_check(id, value))
> +				continue;
> +		} else if (id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE) {
> +			if (!__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor,
> +								    id - RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
> +				continue;
> +		} else {
> +			WARN(1, "This extension id:%d is not in ISA extension list", id);
>  			continue;
> +		}
>  
>  		oldptr = ALT_OLD_PTR(alt);
>  		altptr = ALT_ALT_PTR(alt);
> diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
> new file mode 100644
> index 000000000000..b6c1e7b5d34b
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions.c
> @@ -0,0 +1,56 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2024 Rivos, Inc
> + */
> +
> +#include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +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
> +};
> +
> +const size_t riscv_isa_vendor_ext_list_size = ARRAY_SIZE(riscv_isa_vendor_ext_list);
> +
> +/**
> + * __riscv_isa_vendor_extension_available() - Check whether given vendor
> + * extension is available or not.
> + *
> + * @cpu: check if extension is available on this cpu
> + * @vendor: vendor that the extension is a member of
> + * @bit: bit position of the desired extension
> + * Return: true or false
> + *
> + * NOTE: When cpu is -1, will check if extension is available on all cpus
> + */
> +bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit)
> +{
> +	struct riscv_isavendorinfo *bmap;
> +	struct riscv_isavendorinfo *cpu_bmap;
> +
> +	switch (vendor) {
> +	#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
> +	case ANDES_VENDOR_ID:
> +		bmap = &riscv_isa_vendor_ext_list_andes.all_harts_isa_bitmap;
> +		cpu_bmap = &riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap[cpu];
> +		break;
> +	#endif
> +	default:
> +		return false;
> +	}
> +
> +	if (cpu != -1)
> +		bmap = &cpu_bmap[cpu];
> +
> +	if (bit >= RISCV_ISA_VENDOR_EXT_MAX)
> +		return false;
> +
> +	return test_bit(bit, bmap->isa) ? true : false;
> +}
> +EXPORT_SYMBOL_GPL(__riscv_isa_vendor_extension_available);
> diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
> new file mode 100644
> index 000000000000..6a61aed944f1
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
> diff --git a/arch/riscv/kernel/vendor_extensions/andes.c b/arch/riscv/kernel/vendor_extensions/andes.c
> new file mode 100644
> index 000000000000..ec688c88456a
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions/andes.c
> @@ -0,0 +1,18 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <asm/cpufeature.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
> +
> +#include <linux/array_size.h>
> +#include <linux/types.h>
> +
> +/* All Andes vendor extensions supported in Linux */
> +const struct riscv_isa_ext_data riscv_isa_vendor_ext_andes[] = {
> +	__RISCV_ISA_EXT_DATA(xandespmu, RISCV_ISA_VENDOR_EXT_XANDESPMU),
> +};
> +
> +struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_andes = {
> +	.ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_andes),
> +	.ext_data = riscv_isa_vendor_ext_andes,
> +};
> diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
> index a2e4005e1fd0..02719e0c6368 100644
> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -24,6 +24,8 @@
>  #include <asm/errata_list.h>
>  #include <asm/sbi.h>
>  #include <asm/cpufeature.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/andes.h>
>  
>  #define ALT_SBI_PMU_OVERFLOW(__ovl)					\
>  asm volatile(ALTERNATIVE_2(						\
> @@ -32,7 +34,8 @@ asm volatile(ALTERNATIVE_2(						\
>  		THEAD_VENDOR_ID, ERRATA_THEAD_PMU,			\
>  		CONFIG_ERRATA_THEAD_PMU,				\
>  	"csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF),			\
> -		0, RISCV_ISA_EXT_XANDESPMU,				\
> +		ANDES_VENDOR_ID,					\
> +		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
>  		CONFIG_ANDES_CUSTOM_PMU)				\
>  	: "=r" (__ovl) :						\
>  	: "memory")
> @@ -41,7 +44,8 @@ asm volatile(ALTERNATIVE_2(						\
>  asm volatile(ALTERNATIVE(						\
>  	"csrc " __stringify(CSR_IP) ", %0\n\t",				\
>  	"csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t",			\
> -		0, RISCV_ISA_EXT_XANDESPMU,				\
> +		ANDES_VENDOR_ID,					\
> +		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
>  		CONFIG_ANDES_CUSTOM_PMU)				\
>  	: : "r"(__irq_mask)						\
>  	: "memory")
> @@ -1060,7 +1064,7 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
>  		   riscv_cached_mimpid(0) == 0) {
>  		riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
>  		riscv_pmu_use_irq = true;
> -	} else if (riscv_isa_extension_available(NULL, XANDESPMU) &&
> +	} else if (riscv_isa_vendor_extension_available(ANDES_VENDOR_ID, XANDESPMU) &&
>  		   IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
>  		riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
>  		riscv_pmu_use_irq = true;

[PATCH v2 2/4] riscv: Add vendor extensions to /proc/cpuinfo

[Charlie Jenkins]

All of the supported vendor extensions that have been listed in
riscv_isa_vendor_ext_list can be exported through /proc/cpuinfo.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/kernel/cpu.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index c1f3655238fd..f6b13e9f5e6c 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -16,6 +16,7 @@
 #include <asm/sbi.h>
 #include <asm/smp.h>
 #include <asm/pgtable.h>
+#include <asm/vendor_extensions.h>
 
 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
 {
@@ -235,7 +236,33 @@ arch_initcall(riscv_cpuinfo_init);
 
 #ifdef CONFIG_PROC_FS
 
-static void print_isa(struct seq_file *f, const unsigned long *isa_bitmap)
+#define ALL_CPUS -1
+
+static void print_vendor_isa(struct seq_file *f, int cpu)
+{
+	struct riscv_isavendorinfo *vendor_bitmap;
+	struct riscv_isa_vendor_ext_data_list *ext_list;
+	const struct riscv_isa_ext_data *ext_data;
+
+	for (int i = 0; i < riscv_isa_vendor_ext_list_size; i++) {
+		ext_list = riscv_isa_vendor_ext_list[i];
+		ext_data = riscv_isa_vendor_ext_list[i]->ext_data;
+
+		if (cpu == ALL_CPUS)
+			vendor_bitmap = &ext_list->all_harts_isa_bitmap;
+		else
+			vendor_bitmap = &ext_list->per_hart_isa_bitmap[cpu];
+
+		for (int j = 0; j < ext_list->ext_data_count; j++) {
+			if (!__riscv_isa_extension_available(vendor_bitmap->isa, ext_data[j].id))
+				continue;
+
+			seq_printf(f, "_%s", ext_data[j].name);
+		}
+	}
+}
+
+static void print_isa(struct seq_file *f, const unsigned long *isa_bitmap, int cpu)
 {
 
 	if (IS_ENABLED(CONFIG_32BIT))
@@ -254,6 +281,8 @@ static void print_isa(struct seq_file *f, const unsigned long *isa_bitmap)
 		seq_printf(f, "%s", riscv_isa_ext[i].name);
 	}
 
+	print_vendor_isa(f, cpu);
+
 	seq_puts(f, "\n");
 }
 
@@ -316,7 +345,7 @@ static int c_show(struct seq_file *m, void *v)
 	 * line.
 	 */
 	seq_puts(m, "isa\t\t: ");
-	print_isa(m, NULL);
+	print_isa(m, NULL, ALL_CPUS);
 	print_mmu(m);
 
 	if (acpi_disabled) {
@@ -338,7 +367,7 @@ static int c_show(struct seq_file *m, void *v)
 	 * additional extensions not present across all harts.
 	 */
 	seq_puts(m, "hart isa\t: ");
-	print_isa(m, hart_isa[cpu_id].isa);
+	print_isa(m, hart_isa[cpu_id].isa, cpu_id);
 	seq_puts(m, "\n");
 
 	return 0;

-- 
2.44.0

[PATCH v2 3/4] riscv: Introduce vendor variants of extension helpers

[Charlie Jenkins]

Vendor extensions are maintained in per-vendor structs (separate from
standard extensions which live in riscv_isa). Create vendor variants for
the existing extension helpers to interface with the riscv_isa_vendor
bitmaps.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/include/asm/vendor_extensions.h | 83 ++++++++++++++++++++++++++++++
 drivers/perf/riscv_pmu_sbi.c               |  3 +-
 2 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
index 5fca550fc1f6..04d72b02ae6b 100644
--- a/arch/riscv/include/asm/vendor_extensions.h
+++ b/arch/riscv/include/asm/vendor_extensions.h
@@ -42,8 +42,91 @@ extern const size_t riscv_isa_vendor_ext_list_size;
 #define VENDOR_EXT_ALL_CPUS			-1
 
 bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
+#define riscv_cpu_isa_vendor_extension_available(cpu, vendor, ext)	\
+	__riscv_isa_vendor_extension_available(cpu, vendor, RISCV_ISA_VENDOR_EXT_##ext)
 #define riscv_isa_vendor_extension_available(vendor, ext)	\
 	__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
 					       RISCV_ISA_VENDOR_EXT_##ext)
 
+static __always_inline bool __riscv_has_extension_likely(const unsigned long vendor,
+							 const unsigned long ext)
+{
+	asm goto(ALTERNATIVE("j	%l[l_no]", "nop", %[vendor], %[ext], 1)
+	:
+	: [vendor] "i" (vendor), [ext] "i" (ext)
+	:
+	: l_no);
+
+	return true;
+l_no:
+	return false;
+}
+
+static __always_inline bool __riscv_has_extension_unlikely(const unsigned long vendor,
+							   const unsigned long ext)
+{
+	asm goto(ALTERNATIVE("nop", "j	%l[l_yes]", %[vendor], %[ext], 1)
+	:
+	: [vendor] "i" (vendor), [ext] "i" (ext)
+	:
+	: l_yes);
+
+	return false;
+l_yes:
+	return true;
+}
+
+static __always_inline bool riscv_has_vendor_extension_likely(const unsigned long vendor,
+							      const unsigned long ext)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return false;
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_likely(vendor,
+						    ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
+	return __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, ext);
+}
+
+static __always_inline bool riscv_has_vendor_extension_unlikely(const unsigned long vendor,
+								const unsigned long ext)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return false;
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_unlikely(vendor,
+						      ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+
+	return __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_likely(const unsigned long vendor,
+								  int cpu, const unsigned long ext)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return false;
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+	    __riscv_has_extension_likely(vendor, ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
+		return true;
+
+	return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_unlikely(const unsigned long vendor,
+								    int cpu,
+								    const unsigned long ext)
+{
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
+		return false;
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+	    __riscv_has_extension_unlikely(vendor, ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
+		return true;
+
+	return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
+}
+
 #endif /* _ASM_VENDOR_EXTENSIONS_H */
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 02719e0c6368..e1f0edfb7dcc 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -1064,7 +1064,8 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
 		   riscv_cached_mimpid(0) == 0) {
 		riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
 		riscv_pmu_use_irq = true;
-	} else if (riscv_isa_vendor_extension_available(ANDES_VENDOR_ID, XANDESPMU) &&
+	} else if (riscv_has_vendor_extension_unlikely(ANDES_VENDOR_ID,
+						       RISCV_ISA_VENDOR_EXT_XANDESPMU) &&
 		   IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
 		riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
 		riscv_pmu_use_irq = true;

-- 
2.44.0

Re: [PATCH v2 3/4] riscv: Introduce vendor variants of extension helpers

[Andy Chiu]

On Mon, Jun 10, 2024 at 12:34 PM Charlie Jenkins <charlie@rivosinc.com> wrote:
>
> Vendor extensions are maintained in per-vendor structs (separate from
> standard extensions which live in riscv_isa). Create vendor variants for
> the existing extension helpers to interface with the riscv_isa_vendor
> bitmaps.
>
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

Reviewed-by: Andy Chiu <andy.chiu@sifive.com>

> ---
>  arch/riscv/include/asm/vendor_extensions.h | 83 ++++++++++++++++++++++++++++++
>  drivers/perf/riscv_pmu_sbi.c               |  3 +-
>  2 files changed, 85 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
> index 5fca550fc1f6..04d72b02ae6b 100644
> --- a/arch/riscv/include/asm/vendor_extensions.h
> +++ b/arch/riscv/include/asm/vendor_extensions.h
> @@ -42,8 +42,91 @@ extern const size_t riscv_isa_vendor_ext_list_size;
>  #define VENDOR_EXT_ALL_CPUS                    -1
>
>  bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
> +#define riscv_cpu_isa_vendor_extension_available(cpu, vendor, ext)     \
> +       __riscv_isa_vendor_extension_available(cpu, vendor, RISCV_ISA_VENDOR_EXT_##ext)
>  #define riscv_isa_vendor_extension_available(vendor, ext)      \
>         __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
>                                                RISCV_ISA_VENDOR_EXT_##ext)
>
> +static __always_inline bool __riscv_has_extension_likely(const unsigned long vendor,
> +                                                        const unsigned long ext)
> +{
> +       asm goto(ALTERNATIVE("j %l[l_no]", "nop", %[vendor], %[ext], 1)
> +       :
> +       : [vendor] "i" (vendor), [ext] "i" (ext)
> +       :
> +       : l_no);
> +
> +       return true;
> +l_no:
> +       return false;
> +}
> +
> +static __always_inline bool __riscv_has_extension_unlikely(const unsigned long vendor,
> +                                                          const unsigned long ext)
> +{
> +       asm goto(ALTERNATIVE("nop", "j  %l[l_yes]", %[vendor], %[ext], 1)
> +       :
> +       : [vendor] "i" (vendor), [ext] "i" (ext)
> +       :
> +       : l_yes);
> +
> +       return false;
> +l_yes:
> +       return true;
> +}
> +
> +static __always_inline bool riscv_has_vendor_extension_likely(const unsigned long vendor,
> +                                                             const unsigned long ext)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return false;
> +
> +       if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
> +               return __riscv_has_extension_likely(vendor,
> +                                                   ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
> +       return __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, ext);
> +}
> +
> +static __always_inline bool riscv_has_vendor_extension_unlikely(const unsigned long vendor,
> +                                                               const unsigned long ext)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return false;
> +
> +       if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
> +               return __riscv_has_extension_unlikely(vendor,
> +                                                     ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
> +
> +       return __riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, ext);
> +}
> +
> +static __always_inline bool riscv_cpu_has_vendor_extension_likely(const unsigned long vendor,
> +                                                                 int cpu, const unsigned long ext)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return false;
> +
> +       if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
> +           __riscv_has_extension_likely(vendor, ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
> +               return true;
> +
> +       return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
> +}
> +
> +static __always_inline bool riscv_cpu_has_vendor_extension_unlikely(const unsigned long vendor,
> +                                                                   int cpu,
> +                                                                   const unsigned long ext)
> +{
> +       if (!IS_ENABLED(CONFIG_RISCV_ISA_VENDOR_EXT))
> +               return false;
> +
> +       if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
> +           __riscv_has_extension_unlikely(vendor, ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
> +               return true;
> +
> +       return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
> +}
> +
>  #endif /* _ASM_VENDOR_EXTENSIONS_H */
> diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
> index 02719e0c6368..e1f0edfb7dcc 100644
> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -1064,7 +1064,8 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
>                    riscv_cached_mimpid(0) == 0) {
>                 riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
>                 riscv_pmu_use_irq = true;
> -       } else if (riscv_isa_vendor_extension_available(ANDES_VENDOR_ID, XANDESPMU) &&
> +       } else if (riscv_has_vendor_extension_unlikely(ANDES_VENDOR_ID,
> +                                                      RISCV_ISA_VENDOR_EXT_XANDESPMU) &&
>                    IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
>                 riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
>                 riscv_pmu_use_irq = true;
>
> --
> 2.44.0
>

[PATCH v2 4/4] riscv: cpufeature: Extract common elements from extension checking

[Charlie Jenkins]

The __riscv_has_extension_likely() and __riscv_has_extension_unlikely()
functions from the vendor_extensions.h can be used to simplify the
standard extension checking code as well. Migrate those functions to
cpufeature.h and reorganize the code in the file to use the functions.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/include/asm/cpufeature.h        | 78 +++++++++++++++++-------------
 arch/riscv/include/asm/vendor_extensions.h | 28 -----------
 2 files changed, 44 insertions(+), 62 deletions(-)

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 550d661dc78d..b029ca72cebc 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -96,59 +96,66 @@ extern bool riscv_isa_fallback;
 
 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
 
+#define STANDARD_EXT		0
+
 bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, unsigned int bit);
 #define riscv_isa_extension_available(isa_bitmap, ext)	\
 	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
 
-static __always_inline bool
-riscv_has_extension_likely(const unsigned long ext)
+static __always_inline bool __riscv_has_extension_likely(const unsigned long vendor,
+							 const unsigned long ext)
 {
-	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
-			   "ext must be < RISCV_ISA_EXT_MAX");
-
-	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
-		asm goto(
-		ALTERNATIVE("j	%l[l_no]", "nop", 0, %[ext], 1)
-		:
-		: [ext] "i" (ext)
-		:
-		: l_no);
-	} else {
-		if (!__riscv_isa_extension_available(NULL, ext))
-			goto l_no;
-	}
+	asm goto(ALTERNATIVE("j	%l[l_no]", "nop", %[vendor], %[ext], 1)
+	:
+	: [vendor] "i" (vendor), [ext] "i" (ext)
+	:
+	: l_no);
 
 	return true;
 l_no:
 	return false;
 }
 
-static __always_inline bool
-riscv_has_extension_unlikely(const unsigned long ext)
+static __always_inline bool __riscv_has_extension_unlikely(const unsigned long vendor,
+							   const unsigned long ext)
 {
-	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
-			   "ext must be < RISCV_ISA_EXT_MAX");
-
-	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
-		asm goto(
-		ALTERNATIVE("nop", "j	%l[l_yes]", 0, %[ext], 1)
-		:
-		: [ext] "i" (ext)
-		:
-		: l_yes);
-	} else {
-		if (__riscv_isa_extension_available(NULL, ext))
-			goto l_yes;
-	}
+	asm goto(ALTERNATIVE("nop", "j	%l[l_yes]", %[vendor], %[ext], 1)
+	:
+	: [vendor] "i" (vendor), [ext] "i" (ext)
+	:
+	: l_yes);
 
 	return false;
 l_yes:
 	return true;
 }
 
+static __always_inline bool riscv_has_extension_unlikely(const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_unlikely(STANDARD_EXT, ext);
+
+	return __riscv_isa_extension_available(NULL, ext);
+}
+
+static __always_inline bool riscv_has_extension_likely(const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_likely(STANDARD_EXT, ext);
+
+	return __riscv_isa_extension_available(NULL, ext);
+}
+
 static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext)
 {
-	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_likely(ext))
+	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+	    __riscv_has_extension_likely(STANDARD_EXT, ext))
 		return true;
 
 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
@@ -156,7 +163,10 @@ static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsign
 
 static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext)
 {
-	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_unlikely(ext))
+	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+	    __riscv_has_extension_unlikely(STANDARD_EXT, ext))
 		return true;
 
 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
index 04d72b02ae6b..7437304a71b9 100644
--- a/arch/riscv/include/asm/vendor_extensions.h
+++ b/arch/riscv/include/asm/vendor_extensions.h
@@ -48,34 +48,6 @@ bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsig
 	__riscv_isa_vendor_extension_available(VENDOR_EXT_ALL_CPUS, vendor, \
 					       RISCV_ISA_VENDOR_EXT_##ext)
 
-static __always_inline bool __riscv_has_extension_likely(const unsigned long vendor,
-							 const unsigned long ext)
-{
-	asm goto(ALTERNATIVE("j	%l[l_no]", "nop", %[vendor], %[ext], 1)
-	:
-	: [vendor] "i" (vendor), [ext] "i" (ext)
-	:
-	: l_no);
-
-	return true;
-l_no:
-	return false;
-}
-
-static __always_inline bool __riscv_has_extension_unlikely(const unsigned long vendor,
-							   const unsigned long ext)
-{
-	asm goto(ALTERNATIVE("nop", "j	%l[l_yes]", %[vendor], %[ext], 1)
-	:
-	: [vendor] "i" (vendor), [ext] "i" (ext)
-	:
-	: l_yes);
-
-	return false;
-l_yes:
-	return true;
-}
-
 static __always_inline bool riscv_has_vendor_extension_likely(const unsigned long vendor,
 							      const unsigned long ext)
 {

-- 
2.44.0

Re: [PATCH v2 4/4] riscv: cpufeature: Extract common elements from extension checking

[Andy Chiu]

On Mon, Jun 10, 2024 at 12:34 PM Charlie Jenkins <charlie@rivosinc.com> wrote:
>
> The __riscv_has_extension_likely() and __riscv_has_extension_unlikely()
> functions from the vendor_extensions.h can be used to simplify the
> standard extension checking code as well. Migrate those functions to
> cpufeature.h and reorganize the code in the file to use the functions.
>
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

Reviewed-by: Andy Chiu <andy.chiu@sifive.com>

Re: [PATCH v2 0/4] riscv: Separate vendor extensions from standard extensions

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1289 bytes --]

On Sun, Jun 09, 2024 at 09:34:13PM -0700, Charlie Jenkins wrote:
> All extensions, both standard and vendor, live in one struct
> "riscv_isa_ext". There is currently one vendor extension, xandespmu, but
> it is likely that more vendor extensions will be added to the kernel in
> the future. As more vendor extensions (and standard extensions) are
> added, riscv_isa_ext will become more bloated with a mix of vendor and
> standard extensions.
> 
> This also allows each vendor to be conditionally enabled through
> Kconfig.
> 
> ---
> This has been split out from the previous series that contained the
> addition of xtheadvector due to lack of reviews. The xtheadvector
> support will be posted again separately from this.

I think that's a good call.

> The reviewed-bys on "riscv: Extend cpufeature.c to detect vendor extensions"
> and "riscv: Introduce vendor variants of extension helpers" have been
> dropped in this series. The majority of the code is the same in these
> patches, but thead-specific code is swapped out with andes-specific
> code. The changes are minimal, but I decided to drop the reviews in case
> I inadvertently introduced issues.

Actually, you only completely did that on the first of the two patches
you mention, but I don't mind.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v2 0/4] riscv: Separate vendor extensions from standard extensions

[Charlie Jenkins]

On Thu, Jun 13, 2024 at 03:45:33PM +0100, Conor Dooley wrote:
> On Sun, Jun 09, 2024 at 09:34:13PM -0700, Charlie Jenkins wrote:
> > All extensions, both standard and vendor, live in one struct
> > "riscv_isa_ext". There is currently one vendor extension, xandespmu, but
> > it is likely that more vendor extensions will be added to the kernel in
> > the future. As more vendor extensions (and standard extensions) are
> > added, riscv_isa_ext will become more bloated with a mix of vendor and
> > standard extensions.
> > 
> > This also allows each vendor to be conditionally enabled through
> > Kconfig.
> > 
> > ---
> > This has been split out from the previous series that contained the
> > addition of xtheadvector due to lack of reviews. The xtheadvector
> > support will be posted again separately from this.
> 
> I think that's a good call.
> 
> > The reviewed-bys on "riscv: Extend cpufeature.c to detect vendor extensions"
> > and "riscv: Introduce vendor variants of extension helpers" have been
> > dropped in this series. The majority of the code is the same in these
> > patches, but thead-specific code is swapped out with andes-specific
> > code. The changes are minimal, but I decided to drop the reviews in case
> > I inadvertently introduced issues.
> 
> Actually, you only completely did that on the first of the two patches
> you mention, but I don't mind.

You reviewed the third patch of this series in the first revision of
this series and I should have updated this comment.

- Charlie