irqchip/gic: Add save/restore of the active state

When using EOImode==1, we may mark interrupts as being forwarded
to a virtual machine. In that case, the interrupt is left active
while being passed to the VM.

If we suspend the system before the VM has deactivated the interrupt,
the active state will be lost (which may be very annoying, as this
may result in spurious interrupts and a confused guest).

To avoid this, save and restore the active state together with the
rest of the GIC registers.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1447701208-18150-5-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index bc846e7fec44ee4fea6b027b030f13f05fe581b3..abf2ffaed392270c97d14c7fdc2ab247e63a58e1 100644 (file)
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -73,9 +73,11 @@ struct gic_chip_data {
        union gic_base cpu_base;
 #ifdef CONFIG_CPU_PM
        u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
+       u32 saved_spi_active[DIV_ROUND_UP(1020, 32)];
        u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
        u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
        u32 __percpu *saved_ppi_enable;
+       u32 __percpu *saved_ppi_active;
        u32 __percpu *saved_ppi_conf;
 #endif
        struct irq_domain *domain;
@@ -566,6 +568,10 @@ static void gic_dist_save(unsigned int gic_nr)
        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
                gic_data[gic_nr].saved_spi_enable[i] =
                        readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
+
+       for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
+               gic_data[gic_nr].saved_spi_active[i] =
+                       readl_relaxed(dist_base + GIC_DIST_ACTIVE_SET + i * 4);
 }
 
 /*
@@ -611,6 +617,13 @@ static void gic_dist_restore(unsigned int gic_nr)
                        dist_base + GIC_DIST_ENABLE_SET + i * 4);
        }
 
+       for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++) {
+               writel_relaxed(GICD_INT_EN_CLR_X32,
+                       dist_base + GIC_DIST_ACTIVE_CLEAR + i * 4);
+               writel_relaxed(gic_data[gic_nr].saved_spi_active[i],
+                       dist_base + GIC_DIST_ACTIVE_SET + i * 4);
+       }
+
        writel_relaxed(GICD_ENABLE, dist_base + GIC_DIST_CTRL);
 }
 
@@ -634,6 +647,10 @@ static void gic_cpu_save(unsigned int gic_nr)
        for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
                ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
 
+       ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_active);
+       for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
+               ptr[i] = readl_relaxed(dist_base + GIC_DIST_ACTIVE_SET + i * 4);
+
        ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
        for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
                ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
@@ -663,6 +680,13 @@ static void gic_cpu_restore(unsigned int gic_nr)
                writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);
        }
 
+       ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_active);
+       for (i = 0; i < DIV_ROUND_UP(32, 32); i++) {
+               writel_relaxed(GICD_INT_EN_CLR_X32,
+                              dist_base + GIC_DIST_ACTIVE_CLEAR + i * 4);
+               writel_relaxed(ptr[i], dist_base + GIC_DIST_ACTIVE_SET + i * 4);
+       }
+
        ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
        for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
                writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
@@ -716,6 +740,10 @@ static void __init gic_pm_init(struct gic_chip_data *gic)
                sizeof(u32));
        BUG_ON(!gic->saved_ppi_enable);
 
+       gic->saved_ppi_active = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
+               sizeof(u32));
+       BUG_ON(!gic->saved_ppi_active);
+
        gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
                sizeof(u32));
        BUG_ON(!gic->saved_ppi_conf);