diff options
| -rw-r--r-- | drivers/irqchip/irq-gic.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index abf2ffaed392..541622da7049 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -490,6 +490,7 @@ 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; + DECLARE_BITMAP(sgi_mask, 16); /* * Setting up the CPU map is only relevant for the primary GIC @@ -511,6 +512,58 @@ static void gic_cpu_init(struct gic_chip_data *gic) for (i = 0; i < NR_GIC_CPU_IF; i++) if (i != cpu) gic_cpu_map[i] &= ~cpu_mask; + + /* + * Fiddle with the SGI set/clear registers to try identify + * any IPIs that are reserved for secure world. + */ + bitmap_fill(sgi_mask, 16); + + for (i = 0; i < 16; i++) { + void __iomem *set_reg = + dist_base + GIC_DIST_SGI_PENDING_SET + (i & ~3); + void __iomem *clear_reg = + dist_base + GIC_DIST_SGI_PENDING_CLEAR + (i & ~3); + unsigned long mask = cpu_mask << (8*(i%4)); + unsigned long flags, pending, after_clear, after_set; + + local_irq_save(flags); + + /* record original value */ + pending = readl_relaxed(set_reg); + + /* clear, test, set, and test again */ + writel_relaxed(mask, clear_reg); + after_clear = readl_relaxed(set_reg); + writel_relaxed(mask, set_reg); + after_set = readl_relaxed(set_reg); + + /* restore original value */ + writel_relaxed(mask & ~pending, clear_reg); + + local_irq_restore(flags); + + if (mask & ~after_clear && mask & after_set) + clear_bit(i, sgi_mask); + } + + /* + * Show the SGI mask if it is "interesting". Here interesting + * means that the set/clear register is implemented + * (mask is not full) and it tells us that the secure world + * has reserved some SGIs (mask is not empty). + */ + if (!bitmap_full(sgi_mask, 16) && !bitmap_empty(sgi_mask, 16)) + pr_info("CPU%d: Detected reserved SGI IDs: %*pbl\n", + cpu, 16, sgi_mask); + + /* + * Yell if the reserved IDs make the system unviable. + */ + if (!bitmap_full(sgi_mask, 16) && + find_first_bit(sgi_mask, 16) < NR_IPI) + pr_crit("CPU%d: Not enough SGI IDs; expect failure\n", + cpu); } gic_cpu_config(dist_base, NULL); |