[PATCH v3 14/17] riscv: hwprobe: Add thead vendor extension probing
From: Charlie Jenkins
Date: Sat Apr 20 2024 - 21:08:21 EST
Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0" which
allows userspace to probe for the new RISCV_ISA_VENDOR_EXT_XTHEADVECTOR
vendor extension.
This new key will allow userspace code to probe for which thead vendor
extensions are supported. This API is modeled to be consistent with
RISCV_HWPROBE_KEY_IMA_EXT_0. The bitmask returned will have each bit
corresponding to a supported thead vendor extension of the cpumask set.
Just like RISCV_HWPROBE_KEY_IMA_EXT_0, this allows a userspace program
to determine all of the supported thead vendor extensions in one call.
Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
---
arch/riscv/include/asm/hwprobe.h | 4 +--
.../include/asm/vendor_extensions/thead_hwprobe.h | 11 ++++++
arch/riscv/include/uapi/asm/hwprobe.h | 3 +-
arch/riscv/include/uapi/asm/vendor/thead.h | 3 ++
arch/riscv/kernel/sys_hwprobe.c | 9 +++++
arch/riscv/kernel/vendor_extensions/Makefile | 1 +
.../riscv/kernel/vendor_extensions/thead_hwprobe.c | 42 ++++++++++++++++++++++
7 files changed, 70 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 630507dff5ea..e68496b4f8de 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
- * Copyright 2023 Rivos, Inc
+ * Copyright 2023-2024 Rivos, Inc
*/
#ifndef _ASM_HWPROBE_H
@@ -8,7 +8,7 @@
#include <uapi/asm/hwprobe.h>
-#define RISCV_HWPROBE_MAX_KEY 6
+#define RISCV_HWPROBE_MAX_KEY 7
static inline bool riscv_hwprobe_key_is_valid(__s64 key)
{
diff --git a/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h
new file mode 100644
index 000000000000..907cfc4eb4dc
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H
+
+#include <linux/cpumask.h>
+
+#include <uapi/asm/hwprobe.h>
+
+void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus);
+
+#endif
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 9f2a8e3ff204..21e96a63f9ea 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
- * Copyright 2023 Rivos, Inc
+ * Copyright 2023-2024 Rivos, Inc
*/
#ifndef _UAPI_ASM_HWPROBE_H
@@ -67,6 +67,7 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
#define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
+#define RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 7
/* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
/* Flags */
diff --git a/arch/riscv/include/uapi/asm/vendor/thead.h b/arch/riscv/include/uapi/asm/vendor/thead.h
new file mode 100644
index 000000000000..43790ebe5faf
--- /dev/null
+++ b/arch/riscv/include/uapi/asm/vendor/thead.h
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#define RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR (1 << 0)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 8cae41a502dd..e59cac545df5 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -13,6 +13,7 @@
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/vector.h>
+#include <asm/vendor_extensions/thead_hwprobe.h>
#include <vdso/vsyscall.h>
@@ -216,6 +217,14 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
pair->value = riscv_cboz_block_size;
break;
+ case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
+ hwprobe_isa_vendor_ext_thead_0(pair, cpus);
+#else
+ pair->value = 0;
+#endif
+ break;
+
/*
* For forward compatibility, unknown keys don't fail the whole
* call, but get their element key set to -1 and value set to 0
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
index 8f1c5a4dc38f..f511fd269e8a 100644
--- a/arch/riscv/kernel/vendor_extensions/Makefile
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead_hwprobe.o
obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES) += andes.o
diff --git a/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c
new file mode 100644
index 000000000000..e8e2de292032
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/vector.h>
+#include <asm/vendor_extensions/thead.h>
+#include <asm/vendor_extensions/thead_hwprobe.h>
+
+#include <linux/cpumask.h>
+#include <linux/types.h>
+
+#include <uapi/asm/hwprobe.h>
+#include <uapi/asm/vendor/thead.h>
+
+void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus)
+{
+ /*
+ * Loop through and record extensions that 1) anyone has, and 2) anyone
+ * doesn't have.
+ */
+
+ struct riscv_isainfo *per_hart_thead_bitmap = riscv_isa_vendor_ext_list_thead.per_hart_vendor_bitmap;
+ int cpu;
+ u64 missing;
+
+ for_each_cpu(cpu, cpus) {
+ struct riscv_isainfo *isainfo = &per_hart_thead_bitmap[cpu];
+
+#define EXT_KEY(ext) \
+ do { \
+ if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_VENDOR_EXT_##ext)) \
+ pair->value |= RISCV_HWPROBE_VENDOR_EXT_##ext; \
+ else \
+ missing |= RISCV_HWPROBE_VENDOR_EXT_##ext; \
+ } while (false)
+
+ EXT_KEY(XTHEADVECTOR);
+
+#undef EXT_KEY
+ }
+
+ /* Now turn off reporting features if any CPU is missing it. */
+ pair->value &= ~missing;
+}
--
2.44.0