Re: [PATCH 6/6] MIPS: ath79: irq: Move the CPU IRQ driver to drivers/irqchip

From: Marc Zyngier
Date: Thu Jan 21 2016 - 03:52:27 EST


On 20/01/16 19:46, Alban wrote:
> On Wed, 20 Jan 2016 12:49:48 +0000
> Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
>
>> On Tue, 17 Nov 2015 20:34:56 +0100
>> Alban Bedel <albeu@xxxxxxx> wrote:
>>
>>> Signed-off-by: Alban Bedel <albeu@xxxxxxx>
>>> ---
>>> arch/mips/ath79/irq.c | 81
>>> ++------------------------ arch/mips/include/asm/mach-ath79/ath79.h
>>> | 1 + drivers/irqchip/Makefile | 1 +
>>> drivers/irqchip/irq-ath79-cpu.c | 97
>>> ++++++++++++++++++++++++++++++++ 4 files changed, 105
>>> insertions(+), 75 deletions(-) create mode 100644
>>> drivers/irqchip/irq-ath79-cpu.c
>>>
>
> [...]
>
>>> +asmlinkage void plat_irq_dispatch(void)
>>> +{
>>> + unsigned long pending;
>>> + int irq;
>>> +
>>> + pending = read_c0_status() & read_c0_cause() & ST0_IM;
>>> +
>>> + if (!pending) {
>>> + spurious_interrupt();
>>> + return;
>>> + }
>>> +
>>> + pending >>= CAUSEB_IP;
>>> + while (pending) {
>>> + irq = fls(pending) - 1;
>>> + if (irq < ARRAY_SIZE(irq_wb_chan) && irq_wb_chan[irq] != -1)
>>> + ath79_ddr_wb_flush(irq_wb_chan[irq]);
>>> + do_IRQ(MIPS_CPU_IRQ_BASE + irq);
>>
>> I'm rather unfamiliar with the MIPS IRQ handling, but I'm vaguely
>> surprised by the lack of domain. How do you unsure that the IRQ space
>> used here doesn't clash with the one created in your "misc" irqchip?
>
> This driver extend the irq-mips-cpu driver which take care of setting up
> a legacy domain starting from MIPS_CPU_IRQ_BASE for these interrupts. I
> don't find this very nice either, but this patch is about moving the
> code out of arch/mips, so I tried to minimize unrelated changes.

As long as there is an underlying domain reserving the CPU range, then
this is fine.

So for this patch:

Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>

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