[PATCH 2/2] ARM: vic: MULTI_IRQ_HANDLER handler

[grant.likely@secretlab.ca (Grant Likely)]

On Tue, Sep 27, 2011 at 01:16:42PM +0100, Jamie Iles wrote:
> Add a handler for the VIC that is suitable for MULTI_IRQ_HANDLER
> platforms.  This only works for platforms with CONFIG_OF=y as we can
> determine which controllers are the primary controllers (no parent).
> 
> Signed-off-by: Jamie Iles <jamie@jamieiles.com>
> ---
>  arch/arm/common/vic.c               |   48 +++++++++++++++++++++++++++++++++++
>  arch/arm/include/asm/hardware/vic.h |    1 +
>  2 files changed, 49 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c
> index 3658579..e9b72d3 100644
> --- a/arch/arm/common/vic.c
> +++ b/arch/arm/common/vic.c
> @@ -63,6 +63,22 @@ static struct vic_device vic_devices[CONFIG_ARM_VIC_NR];
>  
>  static int vic_id;
>  
> +#if defined(CONFIG_OF) && defined(CONFIG_MULTI_IRQ_HANDLER)
> +/*
> + * The root VIC's.  We keep track of these so that we can do the IRQ demuxing
> + * as we can have more than one root VIC.
> + */
> +static struct vic_device *vic_root_devices[CONFIG_ARM_VIC_NR];
> +static int nr_root_vics;
> +
> +static void vic_register_root_controller(struct vic_device *vic)
> +{
> +	vic_root_devices[nr_root_vics++] = vic;
> +}
> +#else /* CONFIG_OF && CONFIG_MULTI_IRQ_HANDLER */
> +static inline void vic_register_root_controller(struct vic_device *vic) {}
> +#endif /* CONFIG_OF && CONFIG_MULTI_IRQ_HANDLER */
> +
>  /**
>   * vic_init2 - common initialisation code
>   * @base: Base of the VIC.
> @@ -439,6 +455,9 @@ int __init vic_of_init(struct device_node *node, struct device_node *parent)
>  	vic->domain.ops = &vic_irq_domain_ops;
>  	irq_domain_add(&vic->domain);
>  
> +	if (!parent)
> +		vic_register_root_controller(vic);
> +
>  	return 0;
>  
>  out_unmap:
> @@ -447,4 +466,33 @@ out_unmap:
>  	return -EIO;
>  }
>  
> +#ifdef CONFIG_MULTI_IRQ_HANDLER
> +static void vic_single_handle_irq(struct vic_device *vic, struct pt_regs *regs)
> +{
> +	u32 stat, irq;
> +	bool handled = false;
> +
> +	while (!handled) {
> +		stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
> +		if (!stat)
> +			break;
> +
> +		while (stat) {
> +			irq = fls(stat) - 1;
> +			handle_IRQ(irq + vic->irq, regs);

This is the other reason for irq_domain.  Should use
irq_domain_to_irq() here instead of irq + vic->irq.  (similar to that,
this driver can also be converted to use (struct irq_data*)->hwirq
instead of the ((struct irq_data*)->irq & 32) that it currently uses.
hwirq was added when irq_domains were added.

> +			stat &= ~(1 << irq);
> +			handled = true;
> +		}
> +	}
> +}
> +
> +asmlinkage void __exception_irq_entry vic_handle_irq(struct pt_regs *regs)
> +{
> +	int i;
> +
> +	for (i = 0; i < nr_root_vics; ++i)
> +		vic_single_handle_irq(vic_root_devices[i], regs);
> +}
> +#endif /* CONFIG_MULTI_IRQ_HANDLER */
> +
>  #endif /* CONFIG OF */
> diff --git a/arch/arm/include/asm/hardware/vic.h b/arch/arm/include/asm/hardware/vic.h
> index df1d895..451788c 100644
> --- a/arch/arm/include/asm/hardware/vic.h
> +++ b/arch/arm/include/asm/hardware/vic.h
> @@ -53,6 +53,7 @@ static inline int vic_of_init(struct device_node *node,
>  	return -ENOSYS;
>  }
>  #endif /* CONFIG_OF */
> +void vic_handle_irq(struct pt_regs *regs);
>  #endif /* __ASSEMBLY__ */
>  
>  #endif
> -- 
> 1.7.4.1
> 
> 
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