@@ -479,7 +479,14 @@ asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
nmi_enter();
- /* nop. FIQ handlers for special arch/arm features can be added here. */
+ /*
+ * Either the interrupt controller supports FIQ, meaning it will
+ * do the right thing with this call, or we will end up treating a
+ * spurious FIQ (which is normally fatal) as though it were an IRQ
+ * which, although it risks deadlock, still gives us a sporting
+ * chance of surviving long enough to log errors.
+ */
+ handle_arch_irq(regs);
nmi_exit();
@@ -41,6 +41,7 @@
#include <linux/irqchip/chained_irq.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/irqchip/arm-gic-acpi.h>
+#include <linux/ratelimit.h>
#include <asm/cputype.h>
#include <asm/irq.h>
@@ -50,6 +51,10 @@
#include "irq-gic-common.h"
#include "irqchip.h"
+#ifndef SMP_IPI_FIQ_MASK
+#define SMP_IPI_FIQ_MASK 0
+#endif
+
union gic_base {
void __iomem *common_base;
void __percpu * __iomem *percpu_base;
@@ -67,6 +72,7 @@ struct gic_chip_data {
#endif
struct irq_domain *domain;
unsigned int gic_irqs;
+ bool sgi_with_nsatt;
#ifdef CONFIG_GIC_NON_BANKED
void __iomem *(*get_base)(union gic_base *);
#endif
@@ -285,12 +291,39 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
}
#endif
+/*
+ * Fully acknowledge (both ack and eoi) any outstanding FIQ-based IPI,
+ * otherwise do nothing.
+ */
+void gic_handle_fiq(struct pt_regs *regs)
+{
+ struct gic_chip_data *gic = &gic_data[0];
+ void __iomem *cpu_base = gic_data_cpu_base(gic);
+ unsigned long irqstat, irqnr;
+
+ while ((1u << readl_relaxed(cpu_base + GIC_CPU_HIGHPRI)) &
+ SMP_IPI_FIQ_MASK) {
+ irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
+ writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
+
+ irqnr = irqstat & GICC_IAR_INT_ID_MASK;
+ WARN_RATELIMIT(irqnr > 16,
+ "Unexpected irqnr %lu (bad prioritization?)\n",
+ irqnr);
+ }
+}
+
static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
{
u32 irqstat, irqnr;
struct gic_chip_data *gic = &gic_data[0];
void __iomem *cpu_base = gic_data_cpu_base(gic);
+ if (in_nmi()) {
+ gic_handle_fiq(regs);
+ return;
+ }
+
do {
irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
irqnr = irqstat & GICC_IAR_INT_ID_MASK;
@@ -351,6 +384,55 @@ static struct irq_chip gic_chip = {
.flags = IRQCHIP_SET_TYPE_MASKED,
};
+/*
+ * Shift an interrupt between Group 0 and Group 1.
+ *
+ * In addition to changing the group we also modify the priority to
+ * match what "ARM strongly recommends" for a system where no Group 1
+ * interrupt must ever preempt a Group 0 interrupt.
+ *
+ * If is safe to call this function on systems which do not support
+ * grouping (it will have no effect).
+ */
+static void gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq,
+ int group)
+{
+ void __iomem *base = gic_data_dist_base(gic);
+ unsigned int grp_reg = hwirq / 32 * 4;
+ u32 grp_mask = BIT(hwirq % 32);
+ u32 grp_val;
+
+ unsigned int pri_reg = (hwirq / 4) * 4;
+ u32 pri_mask = BIT(7 + ((hwirq % 4) * 8));
+ u32 pri_val;
+
+ /*
+ * Systems which do not support grouping will have not have
+ * the EnableGrp1 bit set.
+ */
+ if (!(GICD_ENABLE_GRP1 & readl_relaxed(base + GIC_DIST_CTRL)))
+ return;
+
+ raw_spin_lock(&irq_controller_lock);
+
+ grp_val = readl_relaxed(base + GIC_DIST_IGROUP + grp_reg);
+ pri_val = readl_relaxed(base + GIC_DIST_PRI + pri_reg);
+
+ if (group) {
+ grp_val |= grp_mask;
+ pri_val |= pri_mask;
+ } else {
+ grp_val &= ~grp_mask;
+ pri_val &= ~pri_mask;
+ }
+
+ writel_relaxed(grp_val, base + GIC_DIST_IGROUP + grp_reg);
+ writel_relaxed(pri_val, base + GIC_DIST_PRI + pri_reg);
+
+ raw_spin_unlock(&irq_controller_lock);
+}
+
+
void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
{
if (gic_nr >= MAX_GIC_NR)
@@ -382,15 +464,24 @@ static u8 gic_get_cpumask(struct gic_chip_data *gic)
static void gic_cpu_if_up(void)
{
void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
- u32 bypass = 0;
+ void __iomem *dist_base = gic_data_dist_base(&gic_data[0]);
+ u32 ctrl = 0;
/*
- * Preserve bypass disable bits to be written back later
- */
- bypass = readl(cpu_base + GIC_CPU_CTRL);
- bypass &= GICC_DIS_BYPASS_MASK;
+ * Preserve bypass disable bits to be written back later
+ */
+ ctrl = readl(cpu_base + GIC_CPU_CTRL);
+ ctrl &= GICC_DIS_BYPASS_MASK;
+
+ /*
+ * If EnableGrp1 is set in the distributor then enable group 1
+ * support for this CPU (and route group 0 interrupts to FIQ).
+ */
+ if (GICD_ENABLE_GRP1 & readl_relaxed(dist_base + GIC_DIST_CTRL))
+ ctrl |= GICC_COMMON_BPR | GICC_FIQ_EN | GICC_ACK_CTL |
+ GICC_ENABLE_GRP1;
- writel_relaxed(bypass | GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
+ writel_relaxed(ctrl | GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
}
@@ -414,7 +505,34 @@ static void __init gic_dist_init(struct gic_chip_data *gic)
gic_dist_config(base, gic_irqs, NULL);
- writel_relaxed(GICD_ENABLE, base + GIC_DIST_CTRL);
+ /*
+ * Set EnableGrp1/EnableGrp0 (bit 1 and 0) or EnableGrp (bit 0 only,
+ * bit 1 ignored) depending on current mode.
+ */
+ writel_relaxed(GICD_ENABLE_GRP1 | GICD_ENABLE, base + GIC_DIST_CTRL);
+
+ /*
+ * Some GICv1 devices (even those with security extensions) do not
+ * implement EnableGrp1 meaning some parts of the above write might
+ * be ignored. We will only enable FIQ support if the bit can be set.
+ */
+ if (GICD_ENABLE_GRP1 & readl_relaxed(base + GIC_DIST_CTRL)) {
+ /*
+ * Set all global interrupts to be group 1 (signalled with
+ * IRQ).
+ */
+ for (i = 32; i < gic_irqs; i += 32)
+ writel_relaxed(0xffffffff,
+ base + GIC_DIST_IGROUP + i * 4 / 32);
+
+ /*
+ * If the GIC supports the security extension then SGIs
+ * will be filtered based on the value of NSATT. If the
+ * GIC has this support then enable NSATT support.
+ */
+ if (GICD_SECURITY_EXTN & readl_relaxed(base + GIC_DIST_CTR))
+ gic->sgi_with_nsatt = true;
+ }
}
static void gic_cpu_init(struct gic_chip_data *gic)
@@ -423,6 +541,7 @@ static void gic_cpu_init(struct gic_chip_data *gic)
void __iomem *base = gic_data_cpu_base(gic);
unsigned int cpu_mask, cpu = smp_processor_id();
int i;
+ unsigned long ipi_fiq_mask, fiq;
/*
* Get what the GIC says our CPU mask is.
@@ -441,6 +560,23 @@ static void gic_cpu_init(struct gic_chip_data *gic)
gic_cpu_config(dist_base, NULL);
+ /*
+ * If the distributor is configured to support interrupt grouping
+ * then set any PPI and SGI interrupts not set in SMP_IPI_FIQ_MASK
+ * to be group1 and ensure any remaining group 0 interrupts have
+ * the right priority.
+ *
+ * Note that IGROUP[0] is banked, meaning that although we are
+ * writing to a distributor register we are actually performing
+ * part of the per-cpu initialization.
+ */
+ if (GICD_ENABLE_GRP1 & readl_relaxed(dist_base + GIC_DIST_CTRL)) {
+ ipi_fiq_mask = SMP_IPI_FIQ_MASK;
+ writel_relaxed(~ipi_fiq_mask, dist_base + GIC_DIST_IGROUP + 0);
+ for_each_set_bit(fiq, &ipi_fiq_mask, 16)
+ gic_set_group_irq(gic, fiq, 0);
+ }
+
writel_relaxed(GICC_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK);
gic_cpu_if_up();
}
@@ -451,7 +587,8 @@ void gic_cpu_if_down(void)
u32 val = 0;
val = readl(cpu_base + GIC_CPU_CTRL);
- val &= ~GICC_ENABLE;
+ val &= ~(GICC_COMMON_BPR | GICC_FIQ_EN | GICC_ACK_CTL |
+ GICC_ENABLE_GRP1 | GICC_ENABLE);
writel_relaxed(val, cpu_base + GIC_CPU_CTRL);
}
@@ -530,7 +667,8 @@ static void gic_dist_restore(unsigned int gic_nr)
writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
dist_base + GIC_DIST_ENABLE_SET + i * 4);
- writel_relaxed(GICD_ENABLE, dist_base + GIC_DIST_CTRL);
+ writel_relaxed(GICD_ENABLE_GRP1 | GICD_ENABLE,
+ dist_base + GIC_DIST_CTRL);
}
static void gic_cpu_save(unsigned int gic_nr)
@@ -658,6 +796,8 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
{
int cpu;
unsigned long map = 0;
+ unsigned long softint;
+ void __iomem *dist_base;
gic_migration_lock();
@@ -665,14 +805,20 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
for_each_cpu(cpu, mask)
map |= gic_cpu_map[cpu];
+ /* This always happens on GIC0 */
+ dist_base = gic_data_dist_base(&gic_data[0]);
+
/*
* Ensure that stores to Normal memory are visible to the
* other CPUs before they observe us issuing the IPI.
*/
dmb(ishst);
- /* this always happens on GIC0 */
- writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
+ softint = map << 16 | irq;
+
+ writel_relaxed(softint, dist_base + GIC_DIST_SOFTINT);
+ if (gic_data[0].sgi_with_nsatt)
+ writel_relaxed(softint | 0x8000, dist_base + GIC_DIST_SOFTINT);
gic_migration_unlock();
}
@@ -22,6 +22,10 @@
#define GIC_CPU_IDENT 0xfc
#define GICC_ENABLE 0x1
+#define GICC_ENABLE_GRP1 0x2
+#define GICC_ACK_CTL 0x4
+#define GICC_FIQ_EN 0x8
+#define GICC_COMMON_BPR 0x10
#define GICC_INT_PRI_THRESHOLD 0xf0
#define GICC_IAR_INT_ID_MASK 0x3ff
#define GICC_INT_SPURIOUS 1023
@@ -44,7 +48,9 @@
#define GIC_DIST_SGI_PENDING_SET 0xf20
#define GICD_ENABLE 0x1
+#define GICD_ENABLE_GRP1 0x2
#define GICD_DISABLE 0x0
+#define GICD_SECURITY_EXTN 0x400
#define GICD_INT_ACTLOW_LVLTRIG 0x0
#define GICD_INT_EN_CLR_X32 0xffffffff
#define GICD_INT_EN_SET_SGI 0x0000ffff