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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, will.deacon@arm.com,
	dave.martin@arm.com, catalin.marinas@arm.com,
	marc.zyngier@arm.com, mark.rutland@arm.com,
	ard.biesheuvel@linaro.org, jnair@caviumnetworks.com,
	ckadabi@codeaurora.org, robin.murphy@arm.com,
	shankerd@codeaurora.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v4 18/22] arm64: capabilities: Add support for checks based on a list of MIDRs
Date: Tue, 13 Mar 2018 11:51:16 +0000	[thread overview]
Message-ID: <20180313115120.17256-19-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20180313115120.17256-1-suzuki.poulose@arm.com>

Add helpers for detecting an errata on list of midr ranges
of affected CPUs, with the same work around.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/include/asm/cpufeature.h |  1 +
 arch/arm64/include/asm/cputype.h    |  9 +++++
 arch/arm64/kernel/cpu_errata.c      | 81 ++++++++++++++++++++-----------------
 arch/arm64/kernel/cpufeature.c      | 10 +++--
 4 files changed, 60 insertions(+), 41 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index cd245871b578..a16eb0731290 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -314,6 +314,7 @@ struct arm64_cpu_capabilities {
 			} * const fixed_revs;
 		};
 
+		const struct midr_range *midr_range_list;
 		struct {	/* Feature register checking */
 			u32 sys_reg;
 			u8 field_pos;
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index bf6cfdab743f..e86e65c187f8 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -147,6 +147,15 @@ static inline bool is_midr_in_range(u32 midr, struct midr_range const *range)
 				 range->rv_min, range->rv_max);
 }
 
+static inline bool
+is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
+{
+	while (ranges->model)
+		if (is_midr_in_range(midr, ranges++))
+			return true;
+	return false;
+}
+
 /*
  * The CPU ID never changes at run time, so we might as well tell the
  * compiler that it's constant.  Use this function to read the CPU ID
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3c0bb6c4ed02..9490b560d3fe 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -40,6 +40,14 @@ is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
 	return true;
 }
 
+static bool __maybe_unused
+is_affected_midr_range_list(const struct arm64_cpu_capabilities *entry,
+			    int scope)
+{
+	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+	return is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list);
+}
+
 static bool __maybe_unused
 is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
 {
@@ -250,6 +258,10 @@ qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
 	.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,				\
 	CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max)
 
+#define CAP_MIDR_RANGE_LIST(list)				\
+	.matches = is_affected_midr_range_list,			\
+	.midr_range_list = list
+
 /* Errata affecting a range of revisions of  given model variant */
 #define ERRATA_MIDR_REV_RANGE(m, var, r_min, r_max)	 \
 	ERRATA_MIDR_RANGE(m, var, r_min, var, r_max)
@@ -263,6 +275,35 @@ qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
 	.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,			\
 	CAP_MIDR_ALL_VERSIONS(model)
 
+/* Errata affecting a list of midr ranges, with same work around */
+#define ERRATA_MIDR_RANGE_LIST(midr_list)			\
+	.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,			\
+	CAP_MIDR_RANGE_LIST(midr_list)
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+
+/*
+ * List of CPUs where we need to issue a psci call to
+ * harden the branch predictor.
+ */
+static const struct midr_range arm64_bp_harden_smccc_cpus[] = {
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
+	MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
+	MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
+	{},
+};
+
+static const struct midr_range qcom_bp_harden_cpus[] = {
+	MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
+	MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
+	{},
+};
+
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #if	defined(CONFIG_ARM64_ERRATUM_826319) || \
 	defined(CONFIG_ARM64_ERRATUM_827319) || \
@@ -406,51 +447,17 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 	{
 		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
+		ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
 		.cpu_enable = enable_smccc_arch_workaround_1,
 	},
 	{
 		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
-		.cpu_enable = enable_smccc_arch_workaround_1,
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
-		.cpu_enable = enable_smccc_arch_workaround_1,
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
-		.cpu_enable = enable_smccc_arch_workaround_1,
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
+		ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
 		.cpu_enable = qcom_enable_link_stack_sanitization,
 	},
 	{
 		.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
-		.cpu_enable = qcom_enable_link_stack_sanitization,
-	},
-	{
-		.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
-		.cpu_enable = enable_smccc_arch_workaround_1,
-	},
-	{
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
-		.cpu_enable = enable_smccc_arch_workaround_1,
+		ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
 	},
 #endif
 	{
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 006e95d46a4a..fdf6fa5b2f29 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -879,6 +879,11 @@ static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
 static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
 				int scope)
 {
+	/* List of CPUs that are not vulnerable and don't need KPTI */
+	static const struct midr_range kpti_safe_list[] = {
+		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
+		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
+	};
 	char const *str = "command line option";
 
 	/*
@@ -903,11 +908,8 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
 		return true;
 
 	/* Don't force KPTI for CPUs that are not vulnerable */
-	switch (read_cpuid_id() & MIDR_CPU_MODEL_MASK) {
-	case MIDR_CAVIUM_THUNDERX2:
-	case MIDR_BRCM_VULCAN:
+	if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
 		return false;
-	}
 
 	/* Defer to CPU feature registers */
 	return !has_cpuid_feature(entry, scope);
-- 
2.14.3

  parent reply	other threads:[~2018-03-13 11:52 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-13 11:50 [PATCH v4 00/22] arm64: Rework cpu capabilities handling Suzuki K Poulose
2018-03-13 11:50 ` [PATCH v4 01/22] arm64: capabilities: Update prototype for enable call back Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 02/22] arm64: capabilities: Move errata work around check on boot CPU Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 03/22] arm64: capabilities: Move errata processing code Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 04/22] arm64: capabilities: Prepare for fine grained capabilities Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 05/22] arm64: capabilities: Add flags to handle the conflicts on late CPU Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 06/22] arm64: capabilities: Unify the verification Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 07/22] arm64: capabilities: Filter the entries based on a given mask Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 08/22] arm64: capabilities: Prepare for grouping features and errata work arounds Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 09/22] arm64: capabilities: Split the processing of " Suzuki K Poulose
2018-03-22 16:44   ` Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 10/22] arm64: capabilities: Allow features based on local CPU scope Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 11/22] arm64: capabilities: Group handling of features and errata workarounds Suzuki K Poulose
2018-03-21 15:07   ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 12/22] arm64: capabilities: Introduce weak features based on local CPU Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 13/22] arm64: capabilities: Restrict KPTI detection to boot-time CPUs Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 14/22] arm64: capabilities: Add support for features enabled early Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 15/22] arm64: capabilities: Change scope of VHE to Boot CPU feature Suzuki K Poulose
2018-03-21 15:18   ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 16/22] arm64: capabilities: Clean up midr range helpers Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 17/22] arm64: Add helpers for checking CPU MIDR against a range Suzuki K Poulose
2018-03-13 11:51 ` Suzuki K Poulose [this message]
2018-03-13 11:51 ` [PATCH v4 19/22] arm64: capabilities: Handle shared entries Suzuki K Poulose
2018-03-22 16:43   ` Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 20/22] arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35 Suzuki K Poulose
2018-03-13 11:51 ` [PATCH v4 21/22] arm64: Delay enabling hardware DBM feature Suzuki K Poulose
2018-03-21 15:22   ` Dave Martin
2018-03-13 11:51 ` [PATCH v4 22/22] arm64: Add work around for Arm Cortex-A55 Erratum 1024718 Suzuki K Poulose
2018-03-21 15:31   ` Dave Martin
2018-03-22 16:42     ` Suzuki K Poulose
2018-03-26 11:53 ` [PATCH v4 00/22] arm64: Rework cpu capabilities handling Will Deacon

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