Re: [PATCH 06/19] csky: IRQ handling

From: Guo Ren <ren_guo@c-sky.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	daniel.lezcano@linaro.org, jason@lakedaemon.net, arnd@arndb.de,
	c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com,
	thomas.petazzoni@bootlin.com, wbx@uclibc-ng.org
Subject: Re: [PATCH 06/19] csky: IRQ handling
Date: Tue, 20 Mar 2018 10:06:54 +0800	[thread overview]
Message-ID: <20180320020651.GA14709@guoren> (raw)
In-Reply-To: <alpine.DEB.2.21.1803191413300.2010@nanos.tec.linutronix.de>

Hi Thomas,

On Mon, Mar 19, 2018 at 02:16:37PM +0100, Thomas Gleixner wrote:
> > +static inline unsigned long arch_local_irq_save(void)
> > +{
> > +	unsigned long flags;
> 
> Newline between declaration and code please.
OK

> > +void csky_do_IRQ(int irq, struct pt_regs *regs)
> 
> static? If not, then it needs a declaration in a header somewhere.
Yes, need static.

> > +asmlinkage void csky_do_auto_IRQ(struct pt_regs *regs)
> > +{
> > +	unsigned long irq, psr;
> > +
> > +	asm volatile("mfcr %0, psr":"=r"(psr));
> > +
> > +	irq = (psr >> 16) & 0xff;
> > +
> > +	if (irq == 10)
> > +		irq = csky_get_auto_irqno();
> > +	else
> > +		irq -= 32;
> 
> Please add a comment explaining this magic here. Magic numbers w/o
> explanation are bad.
Yes, you are right. I will fixup them next.

PSR is our Processor Status Register and it store the vector number.

'10' is our auto-interrupt exception entry and we need get the irqno
from the interrupt-controller.

The "vector num > 32" is our vector interrupt exception entries, so we
can calculate the irq-num by vector-num and no need to access the
interrupt-controller's io regs.

Best Regards
  Guo Ren