Subject: [PATCH v6 03/15] irq: gic: support hip04 gic

From: [email-masked] (Marc Zyngier)
Date: Tue, 20 May 2014 10:02:47 +0100

On Tue, May 20 2014 at  4:24:08 am BST, Haojian Zhuang <[email-masked]> wrote:
> On 15 May 2014 17:34, Marc Zyngier <[email-masked]> wrote:
>> On 11/05/14 09:05, Haojian Zhuang wrote:
>>>
>>> +static inline bool gic_is_standard(struct gic_chip_data *gic)
>>
>> Please loose all of the inlines. The compiler can do this by itself.
>>
> Since others also agree on inline, I'll keep to use it.
>
>>> -static u8 gic_get_cpumask(struct gic_chip_data *gic)
>>> +static u16 gic_get_cpumask(struct gic_chip_data *gic)
>>>  {
>>>         void __iomem *base = gic_data_dist_base(gic);
>>>         u32 mask, i;
>>>
>>> -       for (i = mask = 0; i < 32; i += 4) {
>>> -               mask = readl_relaxed(base + GIC_DIST_TARGET + i);
>>> -               mask |= mask >> 16;
>>> -               mask |= mask >> 8;
>>> +       /*
>>> +        * ARM GIC uses 8 registers for interrupt 0-31,
>>> +        * HiP04 GIC uses 16 registers for interrupt 0-31.
>>> +        */
>>> +       for (i = mask = 0; i < 32; i += gic_irqs_per_target_reg(gic)) {
>>> +               if (gic_is_standard(gic)) {
>>> +                       mask = readl_relaxed(base + GIC_DIST_TARGET + i);
>>> +                       mask |= mask >> 16;
>>> +                       mask |= mask >> 8;
>>> +               } else {                        /* HiP04 GIC */
>>> +                       mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
>>> +                       mask |= mask >> 16;
>>> +               }
>>
>> You have irq_to_target_reg now, and you can rewrite most of this without
>> duplication (see my previous review comment).
>>
>
> At here, the offset from GIC_DIST_TARGET is got directly.
> In irq_to_target_reg(), the parameter is struct irq_data. These two
> cases are different.
>
> How could I reuse the irq_to_target_reg() at here?

By using your imagination, and redefining irq_to_target_reg to this:

static inline u32 irq_to_target_reg(struct gic_chip_data *gic, int irq)
{
       if (!gic_is_standard(gic))
               i *= 2;
       irq &= ~3U;
       return (i + GIC_DIST_TARGET);
}

You could then try modifying the only existing caller, and then rewrite
the above hunk as such:

       for (i = mask = 0; i < 32; i += gic_irqs_per_target_reg(gic)) {
               mask = readl_relaxed(base + irq_to_target_reg(gic, i));
               mask |= mask >> 16;
               if (gic_is_standard(gic))
                       mask |= mask >> 8;
       }

>
>>> @@ -392,10 +452,17 @@ static void __init gic_dist_init(struct gic_chip_data *gic)
>>>          * Set all global interrupts to this CPU only.
>>>          */
>>>         cpumask = gic_get_cpumask(gic);
>>> -       cpumask |= cpumask << 8;
>>> +       if (gic_is_standard(gic))
>>> +               cpumask |= cpumask << 8;
>>>         cpumask |= cpumask << 16;
>>> -       for (i = 32; i < gic_irqs; i += 4)
>>> -               writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
>>> +       for (i = 32; i < gic_irqs; i += gic_irqs_per_target_reg(gic)) {
>>> +               if (gic_is_standard(gic))
>>> +                       writel_relaxed(cpumask,
>>> +                                      base + GIC_DIST_TARGET + i / 4 * 4);
>>> +               else
>>> +                       writel_relaxed(cpumask,
>>> +                                      base + GIC_DIST_TARGET + i / 2 * 4);
>>> +       }
>>
>> Same here.
>>
> Same reason that I can't use irq_to_target_reg(). There's no struct
> irq_data at here.

	for (i = mask = 0; i < 32; i += gic_irqs_per_target_reg(gic))
		writel_relaxed(cpumask, base + irq_to_target_reg(gic, i));

You might need to move irq_to_target_reg out of the CONFIG_SMP section
as well.

	M.
-- 
Jazz is not dead. It just smells funny.