Thx Marc,

On Fri, May 10, 2019 at 07:12:18PM +0100, Marc Zyngier wrote:
> On Fri, 10 May 2019 09:25:10 +0100,
> Guo Ren <[email protected]> wrote:
> > 
> > Thx Marc,
> > 
> > Sorry for late reply:
> > 
> > On Mon, Feb 18, 2019 at 02:38:23PM +0000, Marc Zyngier wrote:
> > > On Mon, 18 Feb 2019 10:04:40 +0800
> > > [email protected] wrote:
> > > 
> > > > From: Guo Ren <[email protected]>
> > > > 
> > > > Support 4 triger types:
> > > >  - IRQ_TYPE_LEVEL_HIGH
> > > >  - IRQ_TYPE_LEVEL_LOW
> > > >  - IRQ_TYPE_EDGE_RISING
> > > >  - IRQ_TYPE_EDGE_FALLING
> > > > 
> > > > Support 0-255 priority setting for each irq.
> > > > 
> > > > Changelog:
> > > >  - Fixup this_cpu_read() preempted problem.
> > > >  - Optimize the coding style.
> > > > 
> > > > Signed-off-by: Guo Ren <[email protected]>
> > > > Cc: Marc Zyngier <[email protected]>
> > > > ---
> > > >  drivers/irqchip/irq-csky-mpintc.c | 105 
> > > > +++++++++++++++++++++++++++++++++++++-
> > > >  1 file changed, 104 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/irqchip/irq-csky-mpintc.c 
> > > > b/drivers/irqchip/irq-csky-mpintc.c
> > > > index 99d3f3f..07a3752 100644
> > > > --- a/drivers/irqchip/irq-csky-mpintc.c
> > > > +++ b/drivers/irqchip/irq-csky-mpintc.c
> > > > @@ -17,6 +17,7 @@
> > > >  #include <asm/reg_ops.h>
> > > >  
> > > >  static struct irq_domain *root_domain;
> > > > +
> > > >  static void __iomem *INTCG_base;
> > > >  static void __iomem *INTCL_base;
> > > >  
> > > > @@ -29,9 +30,12 @@ static void __iomem *INTCL_base;
> > > >  
> > > >  #define INTCG_ICTLR    0x0
> > > >  #define INTCG_CICFGR   0x100
> > > > +#define INTCG_CIPRTR   0x200
> > > >  #define INTCG_CIDSTR   0x1000
> > > >  
> > > >  #define INTCL_PICTLR   0x0
> > > > +#define INTCL_CFGR     0x14
> > > > +#define INTCL_PRTR     0x20
> > > >  #define INTCL_SIGR     0x60
> > > >  #define INTCL_RDYIR    0x6c
> > > >  #define INTCL_SENR     0xa0
> > > > @@ -40,6 +44,51 @@ static void __iomem *INTCL_base;
> > > >  
> > > >  static DEFINE_PER_CPU(void __iomem *, intcl_reg);
> > > >  
> > > > +static unsigned long *__trigger;
> > > > +static unsigned long *__priority;
> > > > +
> > > > +#define IRQ_OFFSET(irq) ((irq < COMM_IRQ_BASE) ? irq : (irq - 
> > > > COMM_IRQ_BASE))
> > > > +
> > > > +#define TRIG_BYTE_OFFSET(i)    ((((i) * 2) / 32) * 4)
> > > > +#define TRIG_BIT_OFFSET(i)      (((i) * 2) % 32)
> > > > +
> > > > +#define PRI_BYTE_OFFSET(i)     ((((i) * 8) / 32) * 4)
> > > > +#define PRI_BIT_OFFSET(i)       (((i) * 8) % 32)
> > > > +
> > > > +#define TRIG_VAL(trigger, irq) (trigger << 
> > > > TRIG_BIT_OFFSET(IRQ_OFFSET(irq)))
> > > > +#define TRIG_VAL_MSK(irq)          (~(3 << 
> > > > TRIG_BIT_OFFSET(IRQ_OFFSET(irq))))
> > > > +#define PRI_VAL(priority, irq) (priority << 
> > > > PRI_BIT_OFFSET(IRQ_OFFSET(irq)))
> > > > +#define PRI_VAL_MSK(irq)         (~(0xff << 
> > > > PRI_BIT_OFFSET(IRQ_OFFSET(irq))))
> > > > +
> > > > +#define TRIG_BASE(irq) \
> > > > +       (TRIG_BYTE_OFFSET(IRQ_OFFSET(irq)) + ((irq < COMM_IRQ_BASE) ? \
> > > > +       (this_cpu_read(intcl_reg) + INTCL_CFGR) : (INTCG_base + 
> > > > INTCG_CICFGR)))
> > > > +
> > > > +#define PRI_BASE(irq) \
> > > > +       (PRI_BYTE_OFFSET(IRQ_OFFSET(irq)) + ((irq < COMM_IRQ_BASE) ? \
> > > > +       (this_cpu_read(intcl_reg) + INTCL_PRTR) : (INTCG_base + 
> > > > INTCG_CIPRTR)))
> > > > +
> > > > +static DEFINE_SPINLOCK(setup_lock);
> > > > +static void setup_trigger_priority(unsigned long irq, unsigned long 
> > > > trigger,
> > > > +                                  unsigned long priority)
> > > > +{
> > > > +       unsigned int tmp;
> > > > +
> > > > +       spin_lock(&setup_lock);
> > > > +
> > > > +       /* setup trigger */
> > > > +       tmp = readl_relaxed(TRIG_BASE(irq)) & TRIG_VAL_MSK(irq);
> > > > +
> > > > +       writel_relaxed(tmp | TRIG_VAL(trigger, irq), TRIG_BASE(irq));
> > > > +
> > > > +       /* setup priority */
> > > > +       tmp = readl_relaxed(PRI_BASE(irq)) & PRI_VAL_MSK(irq);
> > > > +
> > > > +       writel_relaxed(tmp | PRI_VAL(priority, irq), PRI_BASE(irq));
> > > > +
> > > > +       spin_unlock(&setup_lock);
> > > > +}
> > > > +
> > > >  static void csky_mpintc_handler(struct pt_regs *regs)
> > > >  {
> > > >         void __iomem *reg_base = this_cpu_read(intcl_reg);
> > > > @@ -52,6 +101,9 @@ static void csky_mpintc_enable(struct irq_data *d)
> > > >  {
> > > >         void __iomem *reg_base = this_cpu_read(intcl_reg);
> > > >  
> > > > +       setup_trigger_priority(d->hwirq, __trigger[d->hwirq],
> > > > +                                __priority[d->hwirq]);
> > > > +
> > > >         writel_relaxed(d->hwirq, reg_base + INTCL_SENR);
> > > >  }
> > > >  
> > > > @@ -69,6 +121,28 @@ static void csky_mpintc_eoi(struct irq_data *d)
> > > >         writel_relaxed(d->hwirq, reg_base + INTCL_CACR);
> > > >  }
> > > >  
> > > > +static int csky_mpintc_set_type(struct irq_data *d, unsigned int type)
> > > > +{
> > > > +       switch (type & IRQ_TYPE_SENSE_MASK) {
> > > > +       case IRQ_TYPE_LEVEL_HIGH:
> > > > +               __trigger[d->hwirq] = 0;
> > > > +               break;
> > > > +       case IRQ_TYPE_LEVEL_LOW:
> > > > +               __trigger[d->hwirq] = 1;
> > > > +               break;
> > > > +       case IRQ_TYPE_EDGE_RISING:
> > > > +               __trigger[d->hwirq] = 2;
> > > > +               break;
> > > > +       case IRQ_TYPE_EDGE_FALLING:
> > > > +               __trigger[d->hwirq] = 3;
> > > > +               break;
> > > > +       default:
> > > > +               return -EINVAL;
> > > > +       }
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > >  #ifdef CONFIG_SMP
> > > >  static int csky_irq_set_affinity(struct irq_data *d,
> > > >                                  const struct cpumask *mask_val,
> > > > @@ -101,6 +175,7 @@ static struct irq_chip csky_irq_chip = {
> > > >         .irq_eoi        = csky_mpintc_eoi,
> > > >         .irq_enable     = csky_mpintc_enable,
> > > >         .irq_disable    = csky_mpintc_disable,
> > > > +       .irq_set_type   = csky_mpintc_set_type,
> > > >  #ifdef CONFIG_SMP
> > > >         .irq_set_affinity = csky_irq_set_affinity,
> > > >  #endif
> > > > @@ -121,9 +196,29 @@ static int csky_irqdomain_map(struct irq_domain 
> > > > *d, unsigned int irq,
> > > >         return 0;
> > > >  }
> > > >  
> > > > +static int csky_irq_domain_xlate_cells(struct irq_domain *d,
> > > > +               struct device_node *ctrlr, const u32 *intspec,
> > > > +               unsigned int intsize, unsigned long *out_hwirq,
> > > > +               unsigned int *out_type)
> > > > +{
> > > > +       if (WARN_ON(intsize < 1))
> > > > +               return -EINVAL;
> > > > +
> > > > +       *out_hwirq = intspec[0];
> > > > +       if (intsize > 1)
> > > > +               *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
> > > > +       else
> > > > +               *out_type = IRQ_TYPE_NONE;
> > > 
> > > What does IRQ_TYPE_NONE mean in this context? Shouldn't it actually be
> > > whatever the HW defaults to? Or even better, whatever was expected in
> > > the previous definition of the DT binding?
> > Yes, it shouldn't use IRQ_TYPE_NONE and I'll use
> > > IRQ_TYPE_LEVEL_HIGH.
> 
> I think you should use what the DT gives you and nothing else, unless
> there is some backward compatibility scheme you want to support.
I want backward compatibliltiy scheme, eg:
        interrupts = <34>; (IRQ_TYPE_LEVEL_HIGH priority=0)
        interrupts = <34 IRQ_TYPE_EDGE_RISING>; (priority=0)
        interrupts = <34 IRQ_TYPE_EDGE_RISING 253>; (priority=253)

All of above DT settings could work.

> 
> > 
> > > 
> > > > +
> > > > +       if (intsize > 2)
> > > > +               __priority[*out_hwirq] = intspec[2];
> > > 
> > > And what is the used priority in this case?
> > C-SKY MPINTC could support interrupt's priority and this will be set in
> > INTCG_CIPRTR register. It is set in csky_mpintc_enable function.
> >
> > > 
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > >  static const struct irq_domain_ops csky_irqdomain_ops = {
> > > >         .map    = csky_irqdomain_map,
> > > > -       .xlate  = irq_domain_xlate_onecell,
> > > > +       .xlate  = csky_irq_domain_xlate_cells,
> > > >  };
> > > >  
> > > >  #ifdef CONFIG_SMP
> > > > @@ -157,6 +252,14 @@ csky_mpintc_init(struct device_node *node, struct 
> > > > device_node *parent)
> > > >         if (ret < 0)
> > > >                 nr_irq = INTC_IRQS;
> > > >  
> > > > +       __priority = kcalloc(nr_irq, sizeof(unsigned long), GFP_KERNEL);
> > > > +       if (__priority == NULL)
> > > > +               return -ENXIO;
> > > > +
> > > > +       __trigger  = kcalloc(nr_irq, sizeof(unsigned long), GFP_KERNEL);
> > > > +       if (__trigger == NULL)
> > > > +               return -ENXIO;
> > > 
> > > Maybe you should consider initializing these arrays to something that
> > > makes sense for the case where the DT doesn't carry this information
> > > (which is 100% of the DTs up to this point).
> > Yes, and zero is enough.
> > 
> > /**
> >  * kcalloc - allocate memory for an array. The memory is set to zero.
> >  * @n: number of elements.
> >  * @size: element size.
> >  * @flags: the type of memory to allocate (see kmalloc).
> >  */
> > static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
> > {
> >     return kmalloc_array(n, size, flags | __GFP_ZERO);
> > }
> 
> Trust me, I have a rather precise idea of how kcalloc works, and I
> have a copy of the kernel source handy, so no need to paste it in an
> email.
> 
> My question was about the default values: Everything gets a default
> priority of zero, and nothing seem to set it to another value
> either. So why do we have this allocation anyway?
__priority and __trigger are used to setup interrupt controller's irq
number's priority and trigger type. (See previous answer)

Best Regards
 Guo Ren

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