From 9e350913142b9ea518b13254b4ff0d82b6c0e696 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Fri, 7 Aug 2026 19:24:31 -0600 Subject: [PATCH] RISC-V: Add Smcntrpmf extension parsing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Smcntrpmf extension allows M-mode to enable privilege mode filtering for cycle/instret counters. However, the cyclecfg/instretcfg CSRs are available in Ssccfg only if Smcntrpmf is present. That's why, kernel needs to detect presence of Smcntrpmf extension and enable privilege mode filtering for cycle/instret counters. Reviewed-by: Clément Léger Signed-off-by: Atish Patra Reviewed-by: Charlie Jenkins Tested-by: Charlie Jenkins Link: https://patch.msgid.link/20260807-counter_delegation-v9-6-58658104e487@meta.com Signed-off-by: Paul Walmsley --- arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/kernel/cpufeature.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index d4a7b90e2d78..51ad55b9677a 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -114,6 +114,7 @@ #define RISCV_ISA_EXT_ZICFISS 105 #define RISCV_ISA_EXT_SSCSRIND 106 #define RISCV_ISA_EXT_SMCSRIND 107 +#define RISCV_ISA_EXT_SMCNTRPMF 108 #define RISCV_ISA_EXT_XLINUXENVCFG 127 diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 3fa0a563fb21..1452521d740a 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -576,6 +576,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { __RISCV_ISA_EXT_BUNDLE_VALIDATE(zvksg, riscv_zvksg_bundled_exts, riscv_ext_vector_crypto_validate), __RISCV_ISA_EXT_DATA_VALIDATE(zvkt, RISCV_ISA_EXT_ZVKT, riscv_ext_vector_crypto_validate), __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), + __RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF), __RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND), __RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM), __RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),