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: Vinayak Kale <[email protected]> Signed-off-by: Feng Kan <[email protected]> Reviewed-by: Anup Patel <[email protected]> --- drivers/irqchip/irq-gic.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 9ec3f4c..e70ef38 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -64,6 +64,7 @@ #define GIC_CPU_INT_PRI_THRESHOLD 0xf0 #define GIC_CPU_INT_SPURIOUS 1023 #define GIC_CPU_INT_ID_MASK 0x3ff +#define GIC_CPU_DIS_BYPASS_MASK 0x1e0 union gic_base { void __iomem *common_base; @@ -394,6 +395,20 @@ 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; + + /* + * Preserve bypass disable bits to be written back later + */ + bypass = readl(cpu_base + GIC_CPU_CTRL); + bypass &= GIC_CPU_DIS_BYPASS_MASK; + + writel_relaxed(bypass | GIC_CPU_ENABLE, cpu_base + GIC_CPU_CTRL); +} + static void __init gic_dist_init(struct gic_chip_data *gic) { unsigned int i; @@ -476,13 +491,17 @@ static void gic_cpu_init(struct gic_chip_data *gic) dist_base + GIC_DIST_PRI + i * 4 / 4); writel_relaxed(GIC_CPU_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK); - writel_relaxed(GIC_CPU_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; + + val = readl(cpu_base + GIC_CPU_CTRL); + val &= ~GIC_CPU_ENABLE; + writel_relaxed(val, cpu_base + GIC_CPU_CTRL); } #ifdef CONFIG_CPU_PM @@ -618,7 +637,7 @@ static void gic_cpu_restore(unsigned int gic_nr) dist_base + GIC_DIST_PRI + i * 4); writel_relaxed(GIC_CPU_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK); - writel_relaxed(GIC_CPU_ENABLE, cpu_base + GIC_CPU_CTRL); + gic_cpu_if_up(); } static int gic_notifier(struct notifier_block *self, unsigned long cmd, void *v) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
