This change is made to preserve the GIC v2 bypass bits in the
GIC_CPU_CTRL register (also known as the GICC_CTLR register in spec).
This code will preserve all bits configured by the bootloader regarding
v2 bypass group bits. In the X-Gene platform, the bypass functionality
is not used and bypass bits should not be changed by the kernel gic
code as it could lead to incorrect behavior.
Signed-off-by: Feng Kan <f...@apm.com>
Reviewed-by: Vinayak Kale <vk...@apm.com>
Reviewed-by: Anup Patel <apa...@apm.com>
---
drivers/irqchip/irq-gic.c | 25 ++++++++++++++++++++++---
include/linux/irqchip/arm-gic.h | 1 +
2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 2075d52..c31eea4 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -354,6 +354,21 @@ static u8 gic_get_cpumask(struct gic_chip_data *gic)
return mask;
}
+static void gic_cpu_if_up(void)
+{
+ void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
+ u32 bypass = 0;
+
+ /*
+ * Preserve bypass disable bits to be written back later
+ */
+ bypass = readl(cpu_base + GIC_CPU_CTRL);
+ bypass &= GICC_DIS_BYPASS_MASK;
+
+ writel_relaxed(bypass | GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
+}
+
+
static void __init gic_dist_init(struct gic_chip_data *gic)
{
unsigned int i;
@@ -402,13 +417,17 @@ static void gic_cpu_init(struct gic_chip_data *gic)
gic_cpu_config(dist_base, NULL);
writel_relaxed(GICC_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK);
- writel_relaxed(GICC_ENABLE, base + GIC_CPU_CTRL);
+ gic_cpu_if_up();
}
void gic_cpu_if_down(void)
{
void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
- writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
+ u32 val = 0;
+
+ val = readl(cpu_base + GIC_CPU_CTRL);
+ val &= ~GICC_ENABLE;
+ writel_relaxed(val, cpu_base + GIC_CPU_CTRL);
}
#ifdef CONFIG_CPU_PM
@@ -544,7 +563,7 @@ static void gic_cpu_restore(unsigned int gic_nr)
dist_base + GIC_DIST_PRI + i * 4);
writel_relaxed(GICC_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK);
- writel_relaxed(GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
+ gic_cpu_if_up();
}
static int gic_notifier(struct notifier_block *self, unsigned long cmd,
void *v)
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 5cb9d41..13eed92 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -25,6 +25,7 @@
#define GICC_INT_PRI_THRESHOLD 0xf0
#define GICC_IAR_INT_ID_MASK 0x3ff
#define GICC_INT_SPURIOUS 1023
+#define GICC_DIS_BYPASS_MASK 0x1e0
#define GIC_DIST_CTRL 0x000
#define GIC_DIST_CTR 0x004
--
1.9.1
--
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