From 6d4e11c5e2e8cd54a035ba395bf8ccfa7e22cfd8 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Mon, 21 Sep 2015 22:58:35 +0200 Subject: irqchip/gicv3: Workaround for Cavium ThunderX erratum 23154 This patch implements Cavium ThunderX erratum 23154. The gicv3 of ThunderX requires a modified version for reading the IAR status to ensure data synchronization. Since this is in the fast-path and called with each interrupt, runtime patching is used using jump label patching for smallest overhead (no-op). This is the same technique as used for tracepoints. Signed-off-by: Robert Richter Reviewed-by: Marc Zygnier Acked-by: Catalin Marinas Cc: Tirumalesh Chalamarla Cc: linux-arm-kernel@lists.infradead.org Cc: Jason Cooper Cc: Will Deacon Link: http://lkml.kernel.org/r/1442869119-1814-3-git-send-email-rric@kernel.org Signed-off-by: Thomas Gleixner --- arch/arm64/kernel/cpu_errata.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 6ffd91438560..574450c257a4 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -23,6 +23,7 @@ #define MIDR_CORTEX_A53 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53) #define MIDR_CORTEX_A57 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57) +#define MIDR_THUNDERX MIDR_CPU_PART(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX) #define CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \ MIDR_ARCHITECTURE_MASK) @@ -81,6 +82,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .capability = ARM64_WORKAROUND_845719, MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x04), }, +#endif +#ifdef CONFIG_CAVIUM_ERRATUM_23154 + { + /* Cavium ThunderX, pass 1.x */ + .desc = "Cavium erratum 23154", + .capability = ARM64_WORKAROUND_CAVIUM_23154, + MIDR_RANGE(MIDR_THUNDERX, 0x00, 0x01), + }, #endif { } -- cgit v1.2.3 From d271976dbb31c3ac5653745d03d68c4235d34119 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 30 Sep 2015 11:39:59 +0100 Subject: arm64: el2_setup: Make sure ICC_SRE_EL2.SRE sticks before using GICv3 sysregs Contrary to what was originally expected, EL3 firmware can (for whatever reason) disable GICv3 system register access. In this case, the kernel explodes very early. Work around this by testing if the SRE bit sticks or not. If it doesn't, abort the GICv3 setup, and pray that the firmware has passed a DT that doesn't contain a GICv3 node. Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/kernel/head.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 90d09eddd5b2..351a4de1b1e2 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -498,6 +498,8 @@ CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 orr x0, x0, #ICC_SRE_EL2_ENABLE // Set ICC_SRE_EL2.Enable==1 msr_s ICC_SRE_EL2, x0 isb // Make sure SRE is now set + mrs_s x0, ICC_SRE_EL2 // Read SRE back, + tbz x0, #0, 3f // and check that it sticks msr_s ICH_HCR_EL2, xzr // Reset ICC_HCR_EL2 to defaults 3: -- cgit v1.2.3 From 963fcd40958711cecf9e9a1a8525f88b782d6a98 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 30 Sep 2015 11:50:04 +0100 Subject: arm64: cpufeatures: Check ICC_EL1_SRE.SRE before enabling ARM64_HAS_SYSREG_GIC_CPUIF As the firmware (or the hypervisor) may have disabled SRE access, check that SRE can actually be enabled before declaring that we do have that capability. Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/kernel/cpufeature.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'arch/arm64/kernel') diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 3c9aed32f70b..305f30dc9e63 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -23,6 +23,8 @@ #include #include +#include + static bool feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) { @@ -45,11 +47,26 @@ __ID_FEAT_CHK(id_aa64pfr0); __ID_FEAT_CHK(id_aa64mmfr1); __ID_FEAT_CHK(id_aa64isar0); +static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry) +{ + bool has_sre; + + if (!has_id_aa64pfr0_feature(entry)) + return false; + + has_sre = gic_enable_sre(); + if (!has_sre) + pr_warn_once("%s present but disabled by higher exception level\n", + entry->desc); + + return has_sre; +} + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", .capability = ARM64_HAS_SYSREG_GIC_CPUIF, - .matches = has_id_aa64pfr0_feature, + .matches = has_useable_gicv3_cpuif, .field_pos = 24, .min_field_value = 1, }, -- cgit v1.2.3