[PATCH v3 2/3] RISC-V: hwprobe: Expose Zicbom extension and its block size

[Yunhui Cui <cuiyunhui@bytedance.com>]

Expose Zicbom through hwprobe and also provide a key to extract its
respective block size.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
---
 Documentation/arch/riscv/hwprobe.rst  | 6 ++++++
 arch/riscv/include/asm/hwprobe.h      | 2 +-
 arch/riscv/include/uapi/asm/hwprobe.h | 2 ++
 arch/riscv/kernel/sys_hwprobe.c       | 6 ++++++
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index 955fbcd19ce9..7a47cbdbcf8e 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -94,6 +94,9 @@ The following keys are defined:
   * :c:macro:`RISCV_HWPROBE_EXT_ZICBOZ`: The Zicboz extension is supported, as
        ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.
 
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICBOM`: The Zicbom extension is supported, as
+       ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.
+
   * :c:macro:`RISCV_HWPROBE_EXT_ZBC` The Zbc extension is supported, as defined
        in version 1.0 of the Bit-Manipulation ISA extensions.
 
@@ -273,6 +276,9 @@ The following keys are defined:
 * :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
   represents the size of the Zicboz block in bytes.
 
+* :c:macro:`RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE`: An unsigned int which
+  represents the size of the Zicbom block in bytes.
+
 * :c:macro:`RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS`: An unsigned long which
   represent the highest userspace virtual address usable.
 
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 1ce1df6d0ff3..89379f9a2e6e 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -8,7 +8,7 @@
 
 #include <uapi/asm/hwprobe.h>
 
-#define RISCV_HWPROBE_MAX_KEY 10
+#define RISCV_HWPROBE_MAX_KEY 11
 
 static inline bool riscv_hwprobe_key_is_valid(__s64 key)
 {
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 3af142b99f77..892dd71a3793 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -73,6 +73,7 @@ struct riscv_hwprobe {
 #define		RISCV_HWPROBE_EXT_ZCMOP		(1ULL << 47)
 #define		RISCV_HWPROBE_EXT_ZAWRS		(1ULL << 48)
 #define		RISCV_HWPROBE_EXT_SUPM		(1ULL << 49)
+#define		RISCV_HWPROBE_EXT_ZICBOM	(1ULL << 50)
 #define RISCV_HWPROBE_KEY_CPUPERF_0	5
 #define		RISCV_HWPROBE_MISALIGNED_UNKNOWN	(0 << 0)
 #define		RISCV_HWPROBE_MISALIGNED_EMULATED	(1 << 0)
@@ -90,6 +91,7 @@ struct riscv_hwprobe {
 #define		RISCV_HWPROBE_MISALIGNED_SCALAR_FAST		3
 #define		RISCV_HWPROBE_MISALIGNED_SCALAR_UNSUPPORTED	4
 #define RISCV_HWPROBE_KEY_MISALIGNED_VECTOR_PERF	10
+#define RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE	11
 #define		RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN		0
 #define		RISCV_HWPROBE_MISALIGNED_VECTOR_SLOW		2
 #define		RISCV_HWPROBE_MISALIGNED_VECTOR_FAST		3
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index cb93adfffc48..affcc3e58df9 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -107,6 +107,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
 		EXT_KEY(ZCB);
 		EXT_KEY(ZCMOP);
 		EXT_KEY(ZICBOZ);
+		EXT_KEY(ZICBOM);
 		EXT_KEY(ZICOND);
 		EXT_KEY(ZIHINTNTL);
 		EXT_KEY(ZIHINTPAUSE);
@@ -278,6 +279,11 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
 		if (hwprobe_ext0_has(cpus, RISCV_HWPROBE_EXT_ZICBOZ))
 			pair->value = riscv_cboz_block_size;
 		break;
+	case RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE:
+		pair->value = 0;
+		if (hwprobe_ext0_has(cpus, RISCV_HWPROBE_EXT_ZICBOM))
+			pair->value = riscv_cbom_block_size;
+		break;
 	case RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS:
 		pair->value = user_max_virt_addr();
 		break;
-- 
2.39.2