Re: [PATCH] irqchip/irq-csky-mpintc: Add triger type and priority setting
From: Guo Ren
Date: Fri Jan 18 2019 - 01:28:35 EST
Thx Marc,
On Thu, Jan 17, 2019 at 05:17:45PM +0000, Marc Zyngier wrote:
> Hi Guo,
>
> On 15/01/2019 16:36, guoren@xxxxxxxxxx wrote:
> > From: Guo Ren <ren_guo@xxxxxxxxx>
> >
> > 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.
> >
> > Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
> > ---
> > .../bindings/interrupt-controller/csky,mpintc.txt | 24 ++++++-
> > drivers/irqchip/irq-csky-mpintc.c | 78 +++++++++++++++++++++-
> > 2 files changed, 99 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/csky,mpintc.txt b/Documentation/devicetree/bindings/interrupt-controller/csky,mpintc.txt
> > index ab921f1..364b789 100644
> > --- a/Documentation/devicetree/bindings/interrupt-controller/csky,mpintc.txt
> > +++ b/Documentation/devicetree/bindings/interrupt-controller/csky,mpintc.txt
> > @@ -11,6 +11,14 @@ Interrupt number definition:
> > 16-31 : private irq, and we use 16 as the co-processor timer.
> > 31-1024: common irq for soc ip.
> >
> > +Interrupt triger mode:
> > + IRQ_TYPE_LEVEL_HIGH (default)
> > + IRQ_TYPE_LEVEL_LOW
> > + IRQ_TYPE_EDGE_RISING
> > + IRQ_TYPE_EDGE_FALLING
> > +
> > +Interrupt priority range: 0-255
> > +
> > =============================
> > intc node bindings definition
> > =============================
> > @@ -26,7 +34,7 @@ intc node bindings definition
> > - #interrupt-cells
> > Usage: required
> > Value type: <u32>
> > - Definition: must be <1>
> > + Definition: could be <1> or <2>
> > - interrupt-controller:
> > Usage: required
> >
> > @@ -35,6 +43,18 @@ Examples:
> >
> > intc: interrupt-controller {
> > compatible = "csky,mpintc";
> > - #interrupt-cells = <1>;
> > + #interrupt-cells = <2>;
> > interrupt-controller;
> > };
> > +
> > + 0: device-example {
> > + ...
> > + interrupts = <33 IRQ_TYPE_EDGE_RISING>;
> > + interrupt-parent = <&intc>;
> > + };
> > +
> > + 1: device-example {
> > + ...
> > + interrupts = <34 ((priority << 4) | IRQ_TYPE_EDGE_RISING)>;
> > + interrupt-parent = <&intc>;
> > + };
> > diff --git a/drivers/irqchip/irq-csky-mpintc.c b/drivers/irqchip/irq-csky-mpintc.c
> > index c67c961..9edc6d3 100644
> > --- a/drivers/irqchip/irq-csky-mpintc.c
> > +++ b/drivers/irqchip/irq-csky-mpintc.c
> > @@ -29,9 +29,12 @@ 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_HPPIR 0x68
> > #define INTCL_RDYIR 0x6c
> > @@ -73,6 +76,78 @@ 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)
> > +{
> > + unsigned int priority, triger;
>
> nit: s/triger/trigger/ everywhere.
Ok
>
> > + unsigned int offset, bit_offset;
> > + void __iomem *reg_base;
> > +
> > + /*
> > + * type Bit field: | 32 - 12 | 11 - 4 | 3 - 0 |
> > + * reserved priority triger type
> > + */
> > + triger = type & IRQ_TYPE_SENSE_MASK;
> > + priority = (type >> 4) & 0xff;
>
> Definitely not. The Linux API to set the trigger does not carry any
> priority information, nor should it. Priorities should be set
> statically, and no driver should ever be able to change it.
Currently priority in dts is:
interrupts = <34 ((priority << 4) | IRQ_TYPE_EDGE_RISING)>;
change it to:
interrupts = <34 IRQ_TYPE_EDGE_RISING priority>;
Implement csky own csky_irq_domain_xlate_cells() ...
int csky_irq_domain_xlate_cells(struct irq_domain *d, struct device_node *ctrlr,
const u32 *intspec, unsigned int intsize,
irq_hw_number_t *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;
if (intsize > 2)
setup_priority(d->hwirq, intspec[2]);
return 0;
}
Hmm?
>
> > +
> > + switch (triger) {
> > + case IRQ_TYPE_LEVEL_HIGH:
> > + triger = 0;
> > + break;
> > + case IRQ_TYPE_LEVEL_LOW:
> > + triger = 1;
> > + break;
> > + case IRQ_TYPE_EDGE_RISING:
> > + triger = 2;
> > + break;
> > + case IRQ_TYPE_EDGE_FALLING:
> > + triger = 3;
>
> Can you define some macros that represent these magic values?
OK.
>
> > + break;
> > + default:
> > + triger = 0;
> > + break;
>
> If you get an invalid combination, you shouldn't blindly accept it, but
> instead return an error.
OK.
>
> > + }
> > +
> > + if (d->hwirq < COMM_IRQ_BASE) {
> > + reg_base = this_cpu_read(intcl_reg);
>
> Are you guaranteed to be in a non-preemptible section here? I can see
> things going wrong if not.
???
In percpu-def.h, I see this_cpu_read is safe() for preemption or
interrupt.
/*
* Operations with implied preemption/interrupt protection. These
* operations can be used without worrying about preemption or interrupt.
*/
#define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, pcp)
And:
#define __pcpu_size_call_return(stem, variable) \
({ \
typeof(variable) pscr_ret__; \
__verify_pcpu_ptr(&(variable)); \
switch(sizeof(variable)) { \
case 1: pscr_ret__ = stem##1(variable); break; \
case 2: pscr_ret__ = stem##2(variable); break; \
case 4: pscr_ret__ = stem##4(variable); break; \
case 8: pscr_ret__ = stem##8(variable); break; \
default: \
__bad_size_call_parameter(); break; \
} \
pscr_ret__; \
})
What's the wrong with preemption?
> > +
> > + if (triger) {
> > + offset = ((d->hwirq * 2) / 32) * 4;
> > + bit_offset = (d->hwirq * 2) % 32;
>
> This needs to be turned into a set of macros so that the non-percpu code
> can reuse it.
#define IRQ_OFFSET(irq) \
((irq < COMM_IRQ_BASE) ? irq : irq - COMM_IRQ_BASE)
#define TRIG_VAL(trigger, irq) \
(trigger << ((IRQ_OFFSET(irq) * 2) % 32))
#define TRIG_VAL_MSK(irq) \
(3 << ((IRQ_OFFSET(irq) * 2) % 32))
#define TRIG_BASE(irq) \
((((IRQ_OFFSET(irq) * 2) / 32) * 4) + \
((irq < COMM_IRQ_BASE) ? this_cpu_read(intcl_reg) : INTCG_base))
tmp = readl_relaxed(TRIG_BASE(d->hwirq)) & (~TRIG_VAL_MSK(d->hwirq));
writel_relaxed(tmp | TRIG_VAL(triger, d->hwirq), TRIG_BASE(d->hwirq));
Hmm?
>
> > +
> > + writel_relaxed(triger << bit_offset,
> > + reg_base + INTCL_CFGR + offset);
> > + }
> > +
> > + if (priority) {
> > + offset = ((d->hwirq * 8) / 32) * 4;
> > + bit_offset = (d->hwirq * 8) % 32;
> > +
> > + writel_relaxed(priority << bit_offset,
> > + reg_base + INTCL_PRTR + offset);
> > + }
>
> And this should only be set at boot time.
The same with above reply.
Best Regards
Guo Ren