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-rw-r--r--drivers/irqchip/irq-gic.c87
-rw-r--r--include/linux/irqchip/arm-gic.h4
2 files changed, 88 insertions, 3 deletions
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index ee7c503..268874a 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -253,10 +253,9 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
return -EINVAL;
+ raw_spin_lock(&irq_controller_lock);
mask = 0xff << shift;
bit = gic_cpu_map[cpu] << shift;
-
- raw_spin_lock(&irq_controller_lock);
val = readl_relaxed(reg) & ~mask;
writel_relaxed(val | bit, reg);
raw_spin_unlock(&irq_controller_lock);
@@ -646,7 +645,9 @@ static void __init gic_pm_init(struct gic_chip_data *gic)
void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
{
int cpu;
- unsigned long map = 0;
+ unsigned long flags, map = 0;
+
+ raw_spin_lock_irqsave(&irq_controller_lock, flags);
/* Convert our logical CPU mask into a physical one. */
for_each_cpu(cpu, mask)
@@ -660,6 +661,86 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
/* this always happens on GIC0 */
writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
+
+ raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
+}
+#endif
+
+#ifdef CONFIG_BL_SWITCHER
+/*
+ * gic_migrate_target - migrate IRQs to another CPU interface
+ *
+ * @new_cpu_id: the CPU target ID to migrate IRQs to
+ *
+ * Migrate all peripheral interrupts with a target matching the current CPU
+ * to the interface corresponding to @new_cpu_id. The CPU interface mapping
+ * is also updated. Targets to other CPU interfaces are unchanged.
+ * This must be called with IRQs locally disabled.
+ */
+void gic_migrate_target(unsigned int new_cpu_id)
+{
+ unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
+ void __iomem *dist_base;
+ int i, ror_val, cpu = smp_processor_id();
+ u32 val, cur_target_mask, active_mask;
+
+ if (gic_nr >= MAX_GIC_NR)
+ BUG();
+
+ dist_base = gic_data_dist_base(&gic_data[gic_nr]);
+ if (!dist_base)
+ return;
+ gic_irqs = gic_data[gic_nr].gic_irqs;
+
+ cur_cpu_id = __ffs(gic_cpu_map[cpu]);
+ cur_target_mask = 0x01010101 << cur_cpu_id;
+ ror_val = (cur_cpu_id - new_cpu_id) & 31;
+
+ raw_spin_lock(&irq_controller_lock);
+
+ /* Update the target interface for this logical CPU */
+ gic_cpu_map[cpu] = 1 << new_cpu_id;
+
+ /*
+ * Find all the peripheral interrupts targetting the current
+ * CPU interface and migrate them to the new CPU interface.
+ * We skip DIST_TARGET 0 to 7 as they are read-only.
+ */
+ for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
+ val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
+ active_mask = val & cur_target_mask;
+ if (active_mask) {
+ val &= ~active_mask;
+ val |= ror32(active_mask, ror_val);
+ writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
+ }
+ }
+
+ raw_spin_unlock(&irq_controller_lock);
+
+ /*
+ * Now let's migrate and clear any potential SGIs that might be
+ * pending for us (cur_cpu_id). Since GIC_DIST_SGI_PENDING_SET
+ * is a banked register, we can only forward the SGI using
+ * GIC_DIST_SOFTINT. The original SGI source is lost but Linux
+ * doesn't use that information anyway.
+ *
+ * For the same reason we do not adjust SGI source information
+ * for previously sent SGIs by us to other CPUs either.
+ */
+ for (i = 0; i < 16; i += 4) {
+ int j;
+ val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
+ if (!val)
+ continue;
+ writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
+ for (j = i; j < i + 4; j++) {
+ if (val & 0xff)
+ writel_relaxed((1 << (new_cpu_id + 16)) | j,
+ dist_base + GIC_DIST_SOFTINT);
+ val >>= 8;
+ }
+ }
}
#endif
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 3e203eb..40bfcac 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -31,6 +31,8 @@
#define GIC_DIST_TARGET 0x800
#define GIC_DIST_CONFIG 0xc00
#define GIC_DIST_SOFTINT 0xf00
+#define GIC_DIST_SGI_PENDING_CLEAR 0xf10
+#define GIC_DIST_SGI_PENDING_SET 0xf20
#define GICH_HCR 0x0
#define GICH_VTR 0x4
@@ -73,6 +75,8 @@ static inline void gic_init(unsigned int nr, int start,
gic_init_bases(nr, start, dist, cpu, 0, NULL);
}
+void gic_migrate_target(unsigned int new_cpu_id);
+
#endif /* __ASSEMBLY */
#endif