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-rw-r--r--drivers/irqchip/irq-gic-v3.c66
1 files changed, 59 insertions, 7 deletions
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: