Re: [PATCH 02/21] ARM: gic: Add functions to save and restore gicstate

From: Russell King - ARM Linux
Date: Sun Dec 05 2010 - 18:31:14 EST

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In reply to: Colin Cross: "[PATCH 02/21] ARM: gic: Add functions to save and restore gic state"
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On Sun, Dec 05, 2010 at 03:08:49PM -0800, Colin Cross wrote:
> on systems with idle states which power-gate the logic including
> the gic, such as tegra, the gic distributor needs to be shut down
> and restored on entry and exit from the architecture idle code

This clashes with the GIC cleanups I've previously posted.

> Original-author: Gary King <gking@xxxxxxxxxx>
> Signed-off-by: Gary King <gking@xxxxxxxxxx>
> Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
> ---
> arch/arm/common/gic.c | 136 ++++++++++++++++++++++++++++++++--
> arch/arm/include/asm/hardware/gic.h | 4 +
> 2 files changed, 132 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index 772f95f..9deb34f 100644
> --- a/arch/arm/common/gic.c
> +++ b/arch/arm/common/gic.c
> @@ -39,6 +39,13 @@ struct gic_chip_data {
> unsigned int irq_offset;
> void __iomem *dist_base;
> void __iomem *cpu_base;
> +#ifdef CONFIG_PM
> + u32 saved_enable[DIV_ROUND_UP(1020, 32)];
> + u32 saved_conf[DIV_ROUND_UP(1020, 16)];
> + u32 saved_pri[DIV_ROUND_UP(1020, 4)];
> + u32 saved_target[DIV_ROUND_UP(1020, 4)];
> +#endif
> + unsigned int max_irq;
> };
>
> #ifndef MAX_GIC_NR
> @@ -207,21 +214,15 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
> set_irq_chained_handler(irq, gic_handle_cascade_irq);
> }
>
> -void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
> - unsigned int irq_start)
> +static unsigned int _gic_dist_init(unsigned int gic_nr)
> {
> unsigned int max_irq, i;
> + void __iomem *base = gic_data[gic_nr].dist_base;
> u32 cpumask = 1 << smp_processor_id();
>
> - if (gic_nr >= MAX_GIC_NR)
> - BUG();
> -
> cpumask |= cpumask << 8;
> cpumask |= cpumask << 16;
>
> - gic_data[gic_nr].dist_base = base;
> - gic_data[gic_nr].irq_offset = (irq_start - 1) & ~31;
> -
> writel(0, base + GIC_DIST_CTRL);
>
> /*
> @@ -263,6 +264,109 @@ void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
> for (i = 32; i < max_irq; i += 32)
> writel(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
>
> + return max_irq;
> +}
> +
> +static void _gic_dist_exit(unsigned int gic_nr)
> +{
> + writel(0, gic_data[gic_nr].dist_base + GIC_DIST_CTRL);
> +}
> +
> +#ifdef CONFIG_PM
> +/*
> + * Saves the GIC distributor registers during suspend or idle. Must be called
> + * with interrupts disabled but before powering down the GIC. After calling
> + * this function, no interrupts will be delivered by the GIC, and another
> + * platform-specific wakeup source must be enabled.
> + */
> +void gic_dist_save(unsigned int gic_nr)
> +{
> + unsigned int max_irq = gic_data[gic_nr].max_irq;
> + void __iomem *dist_base = gic_data[gic_nr].dist_base;
> + int i;
> +
> + if (gic_nr >= MAX_GIC_NR)
> + BUG();
> +
> + _gic_dist_exit(gic_nr);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 16); i++)
> + gic_data[gic_nr].saved_conf[i] =
> + readl(dist_base + GIC_DIST_CONFIG + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 4); i++)
> + gic_data[gic_nr].saved_pri[i] =
> + readl(dist_base + GIC_DIST_PRI + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 4); i++)
> + gic_data[gic_nr].saved_target[i] =
> + readl(dist_base + GIC_DIST_TARGET + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 32); i++)
> + gic_data[gic_nr].saved_enable[i] =
> + readl(dist_base + GIC_DIST_ENABLE_SET + i * 4);
> +}
> +
> +/*
> + * Restores the GIC distributor registers during resume or when coming out of
> + * idle. Must be called before enabling interrupts. If a level interrupt
> + * that occured while the GIC was suspended is still present, it will be
> + * handled normally, but any edge interrupts that occured will not be seen by
> + * the GIC and need to be handled by the platform-specific wakeup source.
> + */
> +void gic_dist_restore(unsigned int gic_nr)
> +{
> + unsigned int max_irq;
> + unsigned int i;
> + void __iomem *dist_base;
> + void __iomem *cpu_base;
> +
> + if (gic_nr >= MAX_GIC_NR)
> + BUG();
> +
> + _gic_dist_init(gic_nr);
> +
> + max_irq = gic_data[gic_nr].max_irq;
> + dist_base = gic_data[gic_nr].dist_base;
> + cpu_base = gic_data[gic_nr].cpu_base;
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 16); i++)
> + writel(gic_data[gic_nr].saved_conf[i],
> + dist_base + GIC_DIST_CONFIG + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 4); i++)
> + writel(gic_data[gic_nr].saved_pri[i],
> + dist_base + GIC_DIST_PRI + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 4); i++)
> + writel(gic_data[gic_nr].saved_target[i],
> + dist_base + GIC_DIST_TARGET + i * 4);
> +
> + for (i = 0; i < DIV_ROUND_UP(max_irq, 32); i++)
> + writel(gic_data[gic_nr].saved_enable[i],
> + dist_base + GIC_DIST_ENABLE_SET + i * 4);
> +
> + writel(1, dist_base + GIC_DIST_CTRL);
> + writel(0xf0, cpu_base + GIC_CPU_PRIMASK);
> + writel(1, cpu_base + GIC_CPU_CTRL);
> +}
> +#endif
> +
> +void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
> + unsigned int irq_start)
> +{
> + unsigned int max_irq;
> + unsigned int i;
> +
> + if (gic_nr >= MAX_GIC_NR)
> + BUG();
> +
> + gic_data[gic_nr].dist_base = base;
> + gic_data[gic_nr].irq_offset = (irq_start - 1) & ~31;
> +
> + max_irq = _gic_dist_init(gic_nr);
> + gic_data[gic_nr].max_irq = max_irq;
> +
> /*
> * Setup the Linux IRQ subsystem.
> */
> @@ -276,6 +380,14 @@ void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
> writel(1, base + GIC_DIST_CTRL);
> }
>
> +void gic_dist_exit(unsigned int gic_nr)
> +{
> + if (gic_nr >= MAX_GIC_NR)
> + BUG();
> +
> + _gic_dist_exit(gic_nr);
> +}
> +
> void __cpuinit gic_cpu_init(unsigned int gic_nr, void __iomem *base)
> {
> void __iomem *dist_base;
> @@ -306,6 +418,14 @@ void __cpuinit gic_cpu_init(unsigned int gic_nr, void __iomem *base)
> writel(1, base + GIC_CPU_CTRL);
> }
>
> +void gic_cpu_exit(unsigned int gic_nr)
> +{
> + if (gic_nr >= MAX_GIC_NR)
> + BUG();
> +
> + writel(0, gic_data[gic_nr].cpu_base + GIC_CPU_CTRL);
> +}
> +
> #ifdef CONFIG_SMP
> void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
> {
> diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
> index 7f34333..0a198b0 100644
> --- a/arch/arm/include/asm/hardware/gic.h
> +++ b/arch/arm/include/asm/hardware/gic.h
> @@ -34,7 +34,11 @@
>
> #ifndef __ASSEMBLY__
> void gic_dist_init(unsigned int gic_nr, void __iomem *base, unsigned int irq_start);
> +void gic_dist_save(unsigned int gic_nr);
> +void gic_dist_restore(unsigned int gic_nr);
> +void gic_dist_exit(unsigned int gic_nr);
> void gic_cpu_init(unsigned int gic_nr, void __iomem *base);
> +void gic_cpu_exit(unsigned int gic_nr);
> void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
> void gic_raise_softirq(const struct cpumask *mask, unsigned int irq);
> #endif
> --
> 1.7.3.1
>
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Next message: Minchan Kim: "Re: [PATCH 1/5] mm: kswapd: Stop high-order balancing when anysuitable zone is balanced"
Previous message: FUJITA Tomonori: "Re: dma_unmap_sg - what number of entries is to be passed asparameter really?"
In reply to: Colin Cross: "[PATCH 02/21] ARM: gic: Add functions to save and restore gic state"
Next in thread: Colin Cross: "Re: [PATCH 02/21] ARM: gic: Add functions to save and restore gic state"
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