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From: Charlie Jenkins <charlie@rivosinc.com>
Date: Mon, 15 Apr 2024 21:12:04 -0700
Subject: [PATCH v2 07/17] riscv: Introduce vendor variants of extension
 helpers
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Message-Id: <20240415-dev-charlie-support_thead_vector_6_9-v2-7-c7d68c603268@rivosinc.com>
References: <20240415-dev-charlie-support_thead_vector_6_9-v2-0-c7d68c603268@rivosinc.com>
In-Reply-To: <20240415-dev-charlie-support_thead_vector_6_9-v2-0-c7d68c603268@rivosinc.com>
To: Conor Dooley <conor@kernel.org>, Rob Herring <robh@kernel.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
 Paul Walmsley <paul.walmsley@sifive.com>, 
 Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, 
 Guo Ren <guoren@kernel.org>, Conor Dooley <conor+dt@kernel.org>, 
 Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej.skrabec@gmail.com>, 
 Samuel Holland <samuel@sholland.org>, 
 Conor Dooley <conor.dooley@microchip.com>, Evan Green <evan@rivosinc.com>, 
 =?utf-8?q?Cl=C3=A9ment_L=C3=A9ger?= <cleger@rivosinc.com>, 
 Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>
Cc: linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, 
 linux-kernel@vger.kernel.org, Palmer Dabbelt <palmer@rivosinc.com>, 
 linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, 
 linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, 
 Charlie Jenkins <charlie@rivosinc.com>

Vendor extensions are maintained in riscv_isa_vendor (separate from
standard extensions which live in riscv_isa). Create vendor variants for
the existing extension helpers to interface with the riscv_isa_vendor
bitmap. There is a good amount of overlap between these functions, so
the alternative checking code can be factored out.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
 arch/riscv/errata/sifive/errata.c   |   2 +
 arch/riscv/errata/thead/errata.c    |   2 +
 arch/riscv/include/asm/cpufeature.h | 142 +++++++++++++++++++++++++++---------
 arch/riscv/include/asm/hwprobe.h    |   3 +
 arch/riscv/kernel/cpufeature.c      |  53 ++++++++++++--
 arch/riscv/kernel/sys_hwprobe.c     |   4 +-
 6 files changed, 161 insertions(+), 45 deletions(-)

diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index 3d9a32d791f7..847ff85cc911 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -99,6 +99,8 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 	for (alt = begin; alt < end; alt++) {
 		if (alt->vendor_id != SIFIVE_VENDOR_ID)
 			continue;
+		if (alt->patch_id >= RISCV_ISA_VENDOR_EXT_BASE)
+			continue;
 		if (alt->patch_id >= ERRATA_SIFIVE_NUMBER) {
 			WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id);
 			continue;
diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index b1c410bbc1ae..6e3eabfe92af 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -163,6 +163,8 @@ void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 	for (alt = begin; alt < end; alt++) {
 		if (alt->vendor_id != THEAD_VENDOR_ID)
 			continue;
+		if (alt->patch_id >= RISCV_ISA_VENDOR_EXT_BASE)
+			continue;
 		if (alt->patch_id >= ERRATA_THEAD_NUMBER)
 			continue;
 
diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 50fa174cccb9..12dd36bafa2a 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -110,23 +110,19 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, unsigned i
 #define riscv_isa_extension_available(isa_bitmap, ext)	\
 	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
 
+bool __riscv_isa_vendor_extension_available(const unsigned long *vendor_isa_bitmap,
+					    unsigned int bit);
+#define riscv_isa_vendor_extension_available(isa_bitmap, ext)	\
+	__riscv_isa_vendor_extension_available(isa_bitmap, RISCV_ISA_VENDOR_EXT_##ext)
+
 static __always_inline bool
-riscv_has_extension_likely(const unsigned long ext)
+__riscv_has_extension_likely_alternatives(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:
@@ -134,42 +130,118 @@ riscv_has_extension_likely(const unsigned long ext)
 }
 
 static __always_inline bool
-riscv_has_extension_unlikely(const unsigned long ext)
+__riscv_has_extension_unlikely_alternatives(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;
 }
 
+/* Standard extension helpers */
+
+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_alternatives(0, ext);
+	else
+		return __riscv_isa_extension_available(NULL, ext);
+}
+
+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_alternatives(0, ext);
+	else
+		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))
-		return true;
+	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
+			   "ext must be < RISCV_ISA_EXT_MAX");
 
-	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+	    __riscv_has_extension_likely_alternatives(0, ext))
+		return true;
+	else
+		return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
 }
 
 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_alternatives(0, ext))
 		return true;
+	else
+		return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
+}
+
+/* Vendor extension helpers */
+
+static __always_inline bool
+riscv_has_vendor_extension_likely(const unsigned long vendor, const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_VENDOR_EXT_MAX,
+			   "ext must be < RISCV_ISA_VENDOR_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_likely_alternatives(vendor, ext);
+	else
+		return __riscv_isa_vendor_extension_available(NULL, ext);
+}
 
-	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
+static __always_inline bool
+riscv_has_vendor_extension_unlikely(const unsigned long vendor, const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_VENDOR_EXT_MAX,
+			   "ext must be < RISCV_ISA_VENDOR_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_unlikely_alternatives(vendor, ext);
+	else
+		return __riscv_isa_vendor_extension_available(NULL, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_likely(const unsigned long vendor,
+								  int cpu, const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_VENDOR_EXT_MAX,
+			   "ext must be < RISCV_ISA_VENDOR_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_likely_alternatives(vendor, ext);
+	else
+		return __riscv_isa_vendor_extension_available(hart_isa_vendor[cpu].isa, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_unlikely(const unsigned long vendor,
+								    int cpu,
+								    const unsigned long ext)
+{
+	compiletime_assert(ext < RISCV_ISA_VENDOR_EXT_MAX,
+			   "ext must be < RISCV_ISA_VENDOR_EXT_MAX");
+
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+		return __riscv_has_extension_unlikely_alternatives(vendor, ext);
+	else
+		return __riscv_isa_vendor_extension_available(hart_isa_vendor[cpu].isa, ext);
 }
 
 #endif
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 630507dff5ea..1378c3c9401a 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -6,6 +6,7 @@
 #ifndef _ASM_HWPROBE_H
 #define _ASM_HWPROBE_H
 
+#include <linux/cpumask.h>
 #include <uapi/asm/hwprobe.h>
 
 #define RISCV_HWPROBE_MAX_KEY 6
@@ -39,4 +40,6 @@ static inline bool riscv_hwprobe_pair_cmp(struct riscv_hwprobe *pair,
 	return pair->value == other_pair->value;
 }
 
+void hwprobe_arch_id(struct riscv_hwprobe *pair, const struct cpumask *cpus);
+
 #endif
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index d7a33e017a15..799ec2d2e9e0 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -20,6 +20,7 @@
 #include <asm/cacheflush.h>
 #include <asm/cpufeature.h>
 #include <asm/hwcap.h>
+#include <asm/hwprobe.h>
 #include <asm/patch.h>
 #include <asm/processor.h>
 #include <asm/sbi.h>
@@ -82,6 +83,30 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, unsigned i
 }
 EXPORT_SYMBOL_GPL(__riscv_isa_extension_available);
 
+/**
+ * __riscv_isa_vendor_extension_available() - Check whether given vendor
+ * extension is available or not. The vendor extension must be associated
+ * with the same vendor that was used to populate isa_bitmap.
+ *
+ * @isa_bitmap: ISA bitmap to use
+ * @bit: bit position of the desired extension
+ * Return: true or false
+ *
+ * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
+ */
+bool __riscv_isa_vendor_extension_available(const unsigned long *isa_bitmap, unsigned int bit)
+{
+	const unsigned long *bmap = (isa_bitmap) ? isa_bitmap : riscv_isa_vendor;
+
+	bit -= RISCV_ISA_VENDOR_EXT_BASE;
+
+	if (bit < 0 || bit >= RISCV_ISA_VENDOR_EXT_MAX)
+		return false;
+
+	return test_bit(bit, bmap) ? true : false;
+}
+EXPORT_SYMBOL_GPL(__riscv_isa_vendor_extension_available);
+
 static bool riscv_isa_extension_check(int id)
 {
 	switch (id) {
@@ -832,25 +857,37 @@ 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;
+	struct riscv_hwprobe mvendorid = {
+		.key = RISCV_HWPROBE_KEY_MVENDORID,
+		.value = 0
+	};
 
+	hwprobe_arch_id(&mvendorid, cpu_possible_mask);
+
+	for (alt = begin; alt < end; alt++) {
 		id = PATCH_ID_CPUFEATURE_ID(alt->patch_id);
+		vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id);
 
-		if (id >= RISCV_ISA_EXT_MAX) {
+		if (id >= RISCV_ISA_VENDOR_EXT_BASE) {
+			if (vendor != mvendorid.value ||
+			    !__riscv_isa_vendor_extension_available(NULL, id))
+				continue;
+		} else if (id < RISCV_ISA_EXT_MAX) {
+			if (alt->vendor_id != 0)
+				continue;
+
+			if (!__riscv_isa_extension_available(NULL, id))
+				continue;
+		} else {
 			WARN(1, "This extension id:%d is not in ISA extension list", 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))
 			continue;
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 8cae41a502dd..394f1343490c 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -13,11 +13,11 @@
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/vector.h>
+#include <asm/vendor/thead.h>
 #include <vdso/vsyscall.h>
 
 
-static void hwprobe_arch_id(struct riscv_hwprobe *pair,
-			    const struct cpumask *cpus)
+void hwprobe_arch_id(struct riscv_hwprobe *pair, const struct cpumask *cpus)
 {
 	u64 id = -1ULL;
 	bool first = true;

-- 
2.44.0