From: "Rob Herring (Arm)" <robh@kernel.org>
To: Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org
Subject: [PATCH v4 4/6] arm64/cpufeature: Add field details for ID_AA64DFR1_EL1 register
Date: Tue, 07 Apr 2026 09:29:46 -0500 [thread overview]
Message-ID: <20260407-arm-debug-8-9-v4-4-a4864e69b0ea@kernel.org> (raw)
In-Reply-To: <20260407-arm-debug-8-9-v4-0-a4864e69b0ea@kernel.org>
From: Anshuman Khandual <anshuman.khandual@arm.com>
This adds required field details for ID_AA64DFR1_EL1, and also drops dummy
ftr_raz[] array which is now redundant. These register fields will be used
to enable increased breakpoint and watchpoint registers via FEAT_Debugv8p9
later. The register fields have been marked as FTR_STRICT, unless there is
a known variation in practice.
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
arch/arm64/kernel/cpufeature.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c31f8e17732a..24c8e9147e35 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -570,6 +570,21 @@ static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
ARM64_FTR_END,
};
+static const struct arm64_ftr_bits ftr_id_aa64dfr1[] = {
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_ABL_CMPs_SHIFT, 8, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_DPFZS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_EBEP_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_ITE_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_ABLE_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_PMICNTR_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_SPMU_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_CTX_CMPs_SHIFT, 8, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_WRPs_SHIFT, 8, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_BRPs_SHIFT, 8, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR1_EL1_SYSPMUID_SHIFT, 8, 0),
+ ARM64_FTR_END,
+};
+
static const struct arm64_ftr_bits ftr_mvfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPRound_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, MVFR0_EL1_FPShVec_SHIFT, 4, 0),
@@ -756,10 +771,6 @@ static const struct arm64_ftr_bits ftr_single32[] = {
ARM64_FTR_END,
};
-static const struct arm64_ftr_bits ftr_raz[] = {
- ARM64_FTR_END,
-};
-
#define __ARM64_FTR_REG_OVERRIDE(id_str, id, table, ovr) { \
.sys_id = id, \
.reg = &(struct arm64_ftr_reg){ \
@@ -832,7 +843,7 @@ static const struct __ftr_reg_entry {
/* Op1 = 0, CRn = 0, CRm = 5 */
ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
- ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
+ ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_id_aa64dfr1),
/* Op1 = 0, CRn = 0, CRm = 6 */
ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
--
2.53.0
next prev parent reply other threads:[~2026-04-07 14:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-07 14:29 [PATCH v4 0/6] arm64: Add support for FEAT_Debugv8p9 Rob Herring (Arm)
2026-04-07 14:29 ` [PATCH v4 1/6] arm64: hw_breakpoint: Disallow breakpoints in no kprobe code Rob Herring (Arm)
2026-04-07 14:29 ` [PATCH v4 2/6] arm64: hw_breakpoint: Add additional kprobe excluded functions Rob Herring (Arm)
2026-04-07 14:29 ` [PATCH v4 3/6] arm64: hw_breakpoint: Add lockdep_assert_irqs_disabled() on install/uninstall Rob Herring (Arm)
2026-04-07 14:29 ` Rob Herring (Arm) [this message]
2026-04-07 14:29 ` [PATCH v4 5/6] arm64/boot: Enable EL2 requirements for FEAT_Debugv8p9 Rob Herring (Arm)
2026-04-07 14:29 ` [PATCH v4 6/6] arm64: hw_breakpoint: Enable FEAT_Debugv8p9 Rob Herring (Arm)
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