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authorClément Léger <cleger@rivosinc.com>2024-02-21 09:31:06 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2024-04-28 14:50:38 -0700
commit63f93a3ca891fd90353cf81f5d2fc4cbc3508f1a (patch)
tree0ac58a9ea623c45db680fde97a110db564fe308f /arch/riscv
parent441381506ba7ca1cb8b44e651b130ab791d2e298 (diff)
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riscv: hwprobe: export Zihintpause ISA extension
Export the Zihintpause ISA extension through hwprobe which allows using "pause" instructions. Some userspace applications (OpenJDK for instance) uses this to handle some locking back-off. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240221083108.1235311-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/uapi/asm/hwprobe.h1
-rw-r--r--arch/riscv/kernel/sys_hwprobe.c1
2 files changed, 2 insertions, 0 deletions
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 9f2a8e3ff204..31c570cbd1c5 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -59,6 +59,7 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_EXT_ZTSO (1ULL << 33)
#define RISCV_HWPROBE_EXT_ZACAS (1ULL << 34)
#define RISCV_HWPROBE_EXT_ZICOND (1ULL << 35)
+#define RISCV_HWPROBE_EXT_ZIHINTPAUSE (1ULL << 36)
#define RISCV_HWPROBE_KEY_CPUPERF_0 5
#define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0)
#define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 8cae41a502dd..969ef3d59dbe 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -111,6 +111,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
EXT_KEY(ZTSO);
EXT_KEY(ZACAS);
EXT_KEY(ZICOND);
+ EXT_KEY(ZIHINTPAUSE);
if (has_vector()) {
EXT_KEY(ZVBB);