Re: [PATCH V4 08/17] arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register

From: Suzuki K Poulose
Date: Tue May 19 2020 - 06:49:16 EST


On 05/19/2020 10:40 AM, Anshuman Khandual wrote:
Enable all remaining feature bits like EVT, CCIDX, LSM, HPDS, CnP, XNX,
SpecSEI in ID_MMFR4 register per ARM DDI 0487F.a.

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Suggested-by: Mark Rutland <mark.rutland@xxxxxxx>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/arm64/include/asm/sysreg.h | 8 ++++++++
arch/arm64/kernel/cpufeature.c | 13 +++++++++++++
2 files changed, 21 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 02b1246e7dbf..0a0cbb3add89 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -794,6 +794,14 @@
#define ID_ISAR6_DP_SHIFT 4
#define ID_ISAR6_JSCVT_SHIFT 0
+#define ID_MMFR4_EVT_SHIFT 28
+#define ID_MMFR4_CCIDX_SHIFT 24
+#define ID_MMFR4_LSM_SHIFT 20
+#define ID_MMFR4_HPDS_SHIFT 16
+#define ID_MMFR4_CNP_SHIFT 12
+#define ID_MMFR4_XNX_SHIFT 8
+#define ID_MMFR4_SPECSEI_SHIFT 0
+
#define ID_MMFR5_ETS_SHIFT 0
#define ID_PFR0_DIT_SHIFT 24
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c929aed9fc4b..92186c40b817 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -392,7 +392,20 @@ static const struct arm64_ftr_bits ftr_id_isar5[] = {
};
static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_EVT_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CCIDX_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_LSM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_HPDS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_CNP_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_MMFR4_XNX_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* ac2 */

nit: Please could you add the "ID_MMFR4_AC2_SHIFT", while you are at it ?

Suzuki