[PATCH 1/2] powerpc/8xx: Fix NR_IRQ bugs and refactor 8xx interrupt controller

[Benjamin Herrenschmidt]

On Mon, 2012-04-16 at 14:13 -0600, Grant Likely wrote:
> Ben, I can take these two patches via my irqdomain tree if you prefer.

Let me give them a test run first.

Cheers,
Ben.

> g.
> 
> On Mon, Apr 16, 2012 at 2:13 PM, Grant Likely <grant.likely at secretlab.ca> wrote:
> > The mpc8xx driver uses a reference to NR_IRQS that is buggy.  It uses
> > NR_IRQs for the array size of the ppc_cached_irq_mask bitmap, but
> > NR_IRQs could be smaller than the number of hardware irqs that
> > ppc_cached_irq_mask tracks.
> >
> > Also, while fixing that problem, it became apparent that the interrupt
> > controller only supports 32 interrupt numbers, but it is written as if
> > it supports multiple register banks which is more complicated.
> >
> > This patch pulls out the buggy reference to NR_IRQs and fixes the size
> > of the ppc_cached_irq_mask to match the number of HW irqs.  It also
> > drops the now-unnecessary code since ppc_cached_irq_mask is no longer
> > an array.
> >
> > Signed-off-by: Grant Likely <grant.likely at secretlab.ca>
> > Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> > ---
> >  arch/powerpc/sysdev/mpc8xx_pic.c |   61 +++++++++++++-------------------------
> >  1 file changed, 21 insertions(+), 40 deletions(-)
> >
> > diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
> > index d5f5416..91cade8 100644
> > --- a/arch/powerpc/sysdev/mpc8xx_pic.c
> > +++ b/arch/powerpc/sysdev/mpc8xx_pic.c
> > @@ -18,69 +18,47 @@
> >  extern int cpm_get_irq(struct pt_regs *regs);
> >
> >  static struct irq_domain *mpc8xx_pic_host;
> > -#define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
> > -static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
> > +static unsigned long ppc_cached_irq_mask;
> >  static sysconf8xx_t __iomem *siu_reg;
> >
> >  int cpm_get_irq(struct pt_regs *regs);
> >
> > -static void mpc8xx_unmask_irq(struct irq_data *d)
> > +static inline unsigned long mpc8xx_irqd_to_bit(struct irq_data *d)
> >  {
> > -       int     bit, word;
> > -       unsigned int irq_nr = (unsigned int)irqd_to_hwirq(d);
> > -
> > -       bit = irq_nr & 0x1f;
> > -       word = irq_nr >> 5;
> > +       return 0x80000000 >> irqd_to_hwirq(d);
> > +}
> >
> > -       ppc_cached_irq_mask[word] |= (1 << (31-bit));
> > -       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
> > +static void mpc8xx_unmask_irq(struct irq_data *d)
> > +{
> > +       ppc_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
> > +       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask);
> >  }
> >
> >  static void mpc8xx_mask_irq(struct irq_data *d)
> >  {
> > -       int     bit, word;
> > -       unsigned int irq_nr = (unsigned int)irqd_to_hwirq(d);
> > -
> > -       bit = irq_nr & 0x1f;
> > -       word = irq_nr >> 5;
> > -
> > -       ppc_cached_irq_mask[word] &= ~(1 << (31-bit));
> > -       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
> > +       ppc_cached_irq_mask &= ~mpc8xx_irqd_to_bit(d);
> > +       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask);
> >  }
> >
> >  static void mpc8xx_ack(struct irq_data *d)
> >  {
> > -       int     bit;
> > -       unsigned int irq_nr = (unsigned int)irqd_to_hwirq(d);
> > -
> > -       bit = irq_nr & 0x1f;
> > -       out_be32(&siu_reg->sc_sipend, 1 << (31-bit));
> > +       out_be32(&siu_reg->sc_sipend, mpc8xx_irqd_to_bit(d));
> >  }
> >
> >  static void mpc8xx_end_irq(struct irq_data *d)
> >  {
> > -       int bit, word;
> > -       unsigned int irq_nr = (unsigned int)irqd_to_hwirq(d);
> > -
> > -       bit = irq_nr & 0x1f;
> > -       word = irq_nr >> 5;
> > -
> > -       ppc_cached_irq_mask[word] |= (1 << (31-bit));
> > -       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
> > +       ppc_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
> > +       out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask);
> >  }
> >
> >  static int mpc8xx_set_irq_type(struct irq_data *d, unsigned int flow_type)
> >  {
> > -       if (flow_type & IRQ_TYPE_EDGE_FALLING) {
> > -               irq_hw_number_t hw = (unsigned int)irqd_to_hwirq(d);
> > +       /* only external IRQ senses are programmable */
> > +       if ((flow_type & IRQ_TYPE_EDGE_FALLING) && !(irqd_to_hwirq(d) & 1)) {
> >                unsigned int siel = in_be32(&siu_reg->sc_siel);
> > -
> > -               /* only external IRQ senses are programmable */
> > -               if ((hw & 1) == 0) {
> > -                       siel |= (0x80000000 >> hw);
> > -                       out_be32(&siu_reg->sc_siel, siel);
> > -                       __irq_set_handler_locked(d->irq, handle_edge_irq);
> > -               }
> > +               siel |= mpc8xx_irqd_to_bit(d);
> > +               out_be32(&siu_reg->sc_siel, siel);
> > +               __irq_set_handler_locked(d->irq, handle_edge_irq);
> >        }
> >        return 0;
> >  }
> > @@ -132,6 +110,9 @@ static int mpc8xx_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
> >                IRQ_TYPE_EDGE_FALLING,
> >        };
> >
> > +       if (intspec[0] > 0x1f)
> > +               return 0;
> > +
> >        *out_hwirq = intspec[0];
> >        if (intsize > 1 && intspec[1] < 4)
> >                *out_flags = map_pic_senses[intspec[1]];
> > --
> > 1.7.9.5
> >
> 
> 
>