diff options
| -rw-r--r-- | Documentation/arm64/booting.txt | 5 | ||||
| -rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 66 |
2 files changed, 64 insertions, 7 deletions
diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt index 8df9f4658d6f..fbab7e21d116 100644 --- a/Documentation/arm64/booting.txt +++ b/Documentation/arm64/booting.txt @@ -188,6 +188,11 @@ Before jumping into the kernel, the following conditions must be met: the kernel image will be entered must be initialised by software at a higher exception level to prevent execution in an UNKNOWN state. + - SCR_EL3.FIQ must have the same value across all CPUs the kernel is + executing on. + - The value of SCR_EL3.FIQ must be the same as the one present at boot + time whenever the kernel is executing. + For systems with a GICv3 interrupt controller to be used in v3 mode: - If EL3 is present: ICC_SRE_EL3.Enable (bit 3) must be initialiased to 0b1. diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 5a703ae09ce5..eb9d9486f90b 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -66,6 +66,31 @@ struct gic_chip_data { static struct gic_chip_data gic_data __read_mostly; static DEFINE_STATIC_KEY_TRUE(supports_deactivate_key); +/* + * The behaviours of RPR and PMR registers differ depending on the value of + * SCR_EL3.FIQ, and the behaviour of non-secure priority registers of the + * distributor and redistributors depends on whether security is enabled in the + * GIC. + * + * When security is enabled, non-secure priority values from the (re)distributor + * are presented to the GIC CPUIF as follow: + * (GIC_(R)DIST_PRI[irq] >> 1) | 0x80; + * + * If SCR_EL3.FIQ == 1, the values writen to/read from PMR and RPR at non-secure + * EL1 are subject to a similar operation thus matching the priorities presented + * from the (re)distributor when security is enabled. + * + * see GICv3/GICv4 Architecture Specification (IHI0069D): + * - section 4.8.1 Non-secure accesses to register fields for Secure interrupt + * priorities. + * - Figure 4-7 Secure read of the priority field for a Non-secure Group 1 + * interrupt. + * + * For now, we only support pseudo-NMIs if we have non-secure view of + * priorities. + */ +static DEFINE_STATIC_KEY_FALSE(supports_pseudo_nmis); + static struct gic_kvm_info gic_v3_kvm_info; static DEFINE_PER_CPU(bool, has_rss); @@ -232,6 +257,12 @@ static void gic_unmask_irq(struct irq_data *d) gic_poke_irq(d, GICD_ISENABLER); } +static inline bool gic_supports_nmi(void) +{ + return IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && + static_branch_likely(&supports_pseudo_nmis); +} + static int gic_irq_set_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool val) { @@ -573,6 +604,12 @@ static void gic_update_vlpi_properties(void) !gic_data.rdists.has_direct_lpi ? "no " : ""); } +/* Check whether it's single security state view */ +static inline bool gic_dist_security_disabled(void) +{ + return readl_relaxed(gic_data.dist_base + GICD_CTLR) & GICD_CTLR_DS; +} + static void gic_cpu_sys_reg_init(void) { int i, cpu = smp_processor_id(); @@ -596,8 +633,17 @@ static void gic_cpu_sys_reg_init(void) group0 = gic_has_group0(); /* Set priority mask register */ - if (!gic_prio_masking_enabled()) + if (!gic_prio_masking_enabled()) { write_gicreg(DEFAULT_PMR_VALUE, ICC_PMR_EL1); + } else { + /* + * Mismatch configuration with boot CPU, the system is likely + * to die as interrupt masking will not work properly on all + * CPUs + */ + WARN_ON(gic_supports_nmi() && group0 && + !gic_dist_security_disabled()); + } /* * Some firmwares hand over to the kernel with the BPR changed from @@ -852,12 +898,6 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, #endif #ifdef CONFIG_CPU_PM -/* Check whether it's single security state view */ -static bool gic_dist_security_disabled(void) -{ - return readl_relaxed(gic_data.dist_base + GICD_CTLR) & GICD_CTLR_DS; -} - static int gic_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) { @@ -1110,6 +1150,11 @@ static bool gic_enable_quirk_msm8996(void *data) return true; } +static void gic_enable_nmi_support(void) +{ + static_branch_enable(&supports_pseudo_nmis); +} + static int __init gic_init_bases(void __iomem *dist_base, struct redist_region *rdist_regs, u32 nr_redist_regions, @@ -1179,6 +1224,13 @@ static int __init gic_init_bases(void __iomem *dist_base, its_cpu_init(); } + if (gic_prio_masking_enabled()) { + if (!gic_has_group0() || gic_dist_security_disabled()) + gic_enable_nmi_support(); + else + pr_warn("SCR_EL3.FIQ is cleared, cannot enable use of pseudo-NMIs\n"); + } + return 0; out_free: |