arm smp support patch

[adharmap@codeaurora.org (Abhijeet Dharmapurikar)]

> From: Russell King - ARM Linux <linux@arm.linux.org.uk>
> 
> ARM: GIC: don't disable software generated interrupts
> 
> Software generated interrupts (SGI) are used for IPIs by the kernel.
> While previous revisions of the GIC hardware were specified not to
> implement enable bits for SGIs, more recent hardware is now permitted
> to implement these bits in a per-CPU banked register.
> 
> The priority registers for the PPI and SGIs are also per-CPU banked
> registers, so ensure that these are also appropriately initialized.
> 
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  arch/arm/common/gic.c |   28 ++++++++++++++++++++++++----
>  1 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index ada6359..772f95f 100644
> --- a/arch/arm/common/gic.c
> +++ b/arch/arm/common/gic.c
> @@ -251,15 +251,16 @@ void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
>  		writel(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
>  
>  	/*
> -	 * Set priority on all interrupts.
> +	 * Set priority on all global interrupts.
>  	 */
> -	for (i = 0; i < max_irq; i += 4)
> +	for (i = 32; i < max_irq; i += 4)
>  		writel(0xa0a0a0a0, base + GIC_DIST_PRI + i * 4 / 4);
>  
>  	/*
> -	 * Disable all interrupts.
> +	 * Disable all interrupts.  Leave the PPI and SGIs alone
> +	 * as these enables are banked registers.
>  	 */
> -	for (i = 0; i < max_irq; i += 32)
> +	for (i = 32; i < max_irq; i += 32)
>  		writel(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
>  
>  	/*
> @@ -277,11 +278,30 @@ void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
>  
>  void __cpuinit gic_cpu_init(unsigned int gic_nr, void __iomem *base)
>  {
> +	void __iomem *dist_base;
> +	int i;
> +
>  	if (gic_nr >= MAX_GIC_NR)
>  		BUG();
>  
> +	dist_base = gic_data[gic_nr].dist_base;
> +	BUG_ON(!dist_base);
> +
>  	gic_data[gic_nr].cpu_base = base;
>  
> +	/*
> +	 * Deal with the banked PPI and SGI interrupts - disable all
> +	 * PPI interrupts, ensure all SGI interrupts are enabled.
> +	 */
> +	writel(0xffff0000, dist_base + GIC_DIST_ENABLE_CLEAR);
> +	writel(0x0000ffff, dist_base + GIC_DIST_ENABLE_SET);
> +
> +	/*
> +	 * Set priority on PPI and SGI interrupts
> +	 */
> +	for (i = 0; i < 32; i += 4)
> +		writel(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4);
> +
>  	writel(0xf0, base + GIC_CPU_PRIMASK);
>  	writel(1, base + GIC_CPU_CTRL);
>  }

Tested on msm 8660.

Acked-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>

--
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