Re: [PATCH 01/11] irqchip: Allow irq_reg_{readl,writel} to use __raw_{readl_writel}

[Thomas Gleixner]

On Tue, 28 Oct 2014, Kevin Cernekee wrote:

> On big-endian systems readl/writel may perform an unwanted endian swap,
> breaking generic-chip.c.  Let the platform code opt to use the __raw_
> variants by selecting RAW_IRQ_ACCESSORS.
> 
> This is required in order for bcm3384 to use GENERIC_IRQ_CHIP.  Several
> existing irqchip drivers also use the __raw_ accessors directly, so it
> is a reasonably common requirement.

How does that work with multi arch kernels?

Thanks,

	tglx
 
> Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx>
> ---
>  drivers/irqchip/Kconfig |  3 +++
>  include/linux/irq.h     | 13 +++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index b21f12f..6f0e80b 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -2,6 +2,9 @@ config IRQCHIP
>  	def_bool y
>  	depends on OF_IRQ
>  
> +config RAW_IRQ_ACCESSORS
> +	bool
> +
>  config ARM_GIC
>  	bool
>  	select IRQ_DOMAIN
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 03f48d9..ed1ea8a 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -639,6 +639,17 @@ void arch_teardown_hwirq(unsigned int irq);
>  void irq_init_desc(unsigned int irq);
>  #endif
>  
> +#ifdef CONFIG_RAW_IRQ_ACCESSORS
> +
> +#ifndef irq_reg_writel
> +# define irq_reg_writel(val, addr)	__raw_writel(val, addr)
> +#endif
> +#ifndef irq_reg_readl
> +# define irq_reg_readl(addr)		__raw_readl(addr)
> +#endif
> +
> +#else
> +
>  #ifndef irq_reg_writel
>  # define irq_reg_writel(val, addr)	writel(val, addr)
>  #endif
> @@ -646,6 +657,8 @@ void irq_init_desc(unsigned int irq);
>  # define irq_reg_readl(addr)		readl(addr)
>  #endif
>  
> +#endif
> +
>  /**
>   * struct irq_chip_regs - register offsets for struct irq_gci
>   * @enable:	Enable register offset to reg_base
> -- 
> 2.1.1
> 
> 
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