Re: linux-next: Tree for Sep 1

[Nicolas Pitre <nicolas.pitre@linaro.org>]

On Tue, 2 Sep 2014, Christoph Lameter wrote:

> On Tue, 2 Sep 2014, Christoph Lameter wrote:
> 
> > Oww.. This is double indirection deal there. A percpu offset pointing to
> > a pointer?
> >
> > Generally the following is true (definition from
> > include/asm-generic/percpu.h that is used for ARM for raw_cpu_read):
> >
> > #define raw_cpu_read_4(pcp)             (*raw_cpu_ptr(&(pcp)))
> 
> I think what the issue is that we dropped the fetch of the percpu offset
> in the patch. Instead we are using the address of the variable that
> contains the offset. Does this patch fix it?
> 
> 
> Subject: irqchip: Properly fetch the per cpu offset
> 
> The raw_cpu_read() conversion dropped the fetch of the offset
> from base->percpu_base in gic_get_percpu_base.
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>
> 
> Index: linux/drivers/irqchip/irq-gic.c
> ===================================================================
> --- linux.orig/drivers/irqchip/irq-gic.c
> +++ linux/drivers/irqchip/irq-gic.c
> @@ -102,7 +102,7 @@ static struct gic_chip_data gic_data[MAX
>  #ifdef CONFIG_GIC_NON_BANKED
>  static void __iomem *gic_get_percpu_base(union gic_base *base)
>  {
> -	return raw_cpu_read(base->percpu_base);
> +	return raw_cpu_read(*base->percpu_base);

Isn't the pointer dereference supposed to be performed _outside_ the per 
CPU accessor?


Nicolas