Re: [PATCH v4 2/4] irq: add irq_domain support to generic-chip

From: Shawn Guo
Date: Sat Feb 04 2012 - 08:55:31 EST


On Fri, Feb 03, 2012 at 04:35:10PM -0600, Rob Herring wrote:
> From: Rob Herring <rob.herring@xxxxxxxxxxx>
>
> Add irq domain support to irq generic-chip. This enables users of
> generic-chip to support dynamic irq assignment needed for DT interrupt
> binding.
>
> Signed-off-by: Rob Herring <rob.herring@xxxxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> include/linux/irq.h | 15 +++++
> kernel/irq/generic-chip.c | 154 ++++++++++++++++++++++++++++++++++++++-------
> 2 files changed, 147 insertions(+), 22 deletions(-)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index bff29c5..d721abc 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -664,7 +664,12 @@ struct irq_chip_generic {
> raw_spinlock_t lock;
> void __iomem *reg_base;
> unsigned int irq_base;
> + unsigned int hwirq_base;
> unsigned int irq_cnt;
> + struct irq_domain *domain;
> + unsigned int flags;
> + unsigned int irq_set;
> + unsigned int irq_clr;
> u32 mask_cache;
> u32 type_cache;
> u32 polarity_cache;
> @@ -707,6 +712,16 @@ irq_alloc_generic_chip(const char *name, int nr_ct, unsigned int irq_base,
> void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
> enum irq_gc_flags flags, unsigned int clr,
> unsigned int set);
> +
> +struct device_node;
> +int irq_setup_generic_chip_domain(const char *name, struct device_node *node,
> + int num_ct, unsigned int irq_base,
> + void __iomem *reg_base,
> + irq_flow_handler_t handler, u32 hwirq_cnt,
> + enum irq_gc_flags flags,
> + unsigned int clr, unsigned int set,
> + void (*gc_init_cb)(struct irq_chip_generic *),
> + void *private);
> int irq_setup_alt_chip(struct irq_data *d, unsigned int type);
> void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
> unsigned int clr, unsigned int set);
> diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
> index c89295a..ffbe6fe 100644
> --- a/kernel/irq/generic-chip.c
> +++ b/kernel/irq/generic-chip.c
> @@ -5,6 +5,7 @@
> */
> #include <linux/io.h>
> #include <linux/irq.h>
> +#include <linux/irqdomain.h>
> #include <linux/slab.h>
> #include <linux/export.h>
> #include <linux/interrupt.h>
> @@ -39,7 +40,7 @@ void irq_gc_noop(struct irq_data *d)
> void irq_gc_mask_disable_reg(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> irq_reg_writel(mask, gc->reg_base + cur_regs(d)->disable);
> @@ -57,7 +58,7 @@ void irq_gc_mask_disable_reg(struct irq_data *d)
> void irq_gc_mask_set_bit(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> gc->mask_cache |= mask;
> @@ -75,7 +76,7 @@ void irq_gc_mask_set_bit(struct irq_data *d)
> void irq_gc_mask_clr_bit(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> gc->mask_cache &= ~mask;
> @@ -93,7 +94,7 @@ void irq_gc_mask_clr_bit(struct irq_data *d)
> void irq_gc_unmask_enable_reg(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> irq_reg_writel(mask, gc->reg_base + cur_regs(d)->enable);
> @@ -108,7 +109,7 @@ void irq_gc_unmask_enable_reg(struct irq_data *d)
> void irq_gc_ack_set_bit(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
> @@ -122,10 +123,10 @@ void irq_gc_ack_set_bit(struct irq_data *d)
> void irq_gc_ack_clr_bit(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = ~(1 << (d->irq - gc->irq_base));
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> - irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
> + irq_reg_writel(~mask, gc->reg_base + cur_regs(d)->ack);
> irq_gc_unlock(gc);
> }
>
> @@ -136,7 +137,7 @@ void irq_gc_ack_clr_bit(struct irq_data *d)
> void irq_gc_mask_disable_reg_and_ack(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> irq_reg_writel(mask, gc->reg_base + cur_regs(d)->mask);
> @@ -151,7 +152,7 @@ void irq_gc_mask_disable_reg_and_ack(struct irq_data *d)
> void irq_gc_eoi(struct irq_data *d)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> irq_gc_lock(gc);
> irq_reg_writel(mask, gc->reg_base + cur_regs(d)->eoi);
> @@ -169,7 +170,7 @@ void irq_gc_eoi(struct irq_data *d)
> int irq_gc_set_wake(struct irq_data *d, unsigned int on)
> {
> struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> - u32 mask = 1 << (d->irq - gc->irq_base);
> + u32 mask = (1 << d->hwirq) % 32;
>
> if (!(mask & gc->wake_enabled))
> return -EINVAL;
> @@ -220,6 +221,18 @@ EXPORT_SYMBOL_GPL(irq_alloc_generic_chip);
> */
> static struct lock_class_key irq_nested_lock_class;
>
> +static void irq_gc_setup_irq(struct irq_chip_generic *gc, int irq)
> +{
> + struct irq_chip_type *ct = gc->chip_types;
> +
> + if (gc->flags & IRQ_GC_INIT_NESTED_LOCK)
> + irq_set_lockdep_class(irq, &irq_nested_lock_class);
> +
> + irq_set_chip_and_handler(irq, &ct->chip, ct->handler);
> + irq_set_chip_data(irq, gc);
> + irq_modify_status(irq, gc->irq_clr, gc->irq_set);
> +}
> +
> /**
> * irq_setup_generic_chip - Setup a range of interrupts with a generic chip
> * @gc: Generic irq chip holding all data
> @@ -247,21 +260,115 @@ void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
> if (flags & IRQ_GC_INIT_MASK_CACHE)
> gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask);
>
> + gc->flags = flags;
> + gc->irq_clr = clr;
> + gc->irq_set = set;
> +
> for (i = gc->irq_base; msk; msk >>= 1, i++) {
> if (!(msk & 0x01))
> continue;
>
> - if (flags & IRQ_GC_INIT_NESTED_LOCK)
> - irq_set_lockdep_class(i, &irq_nested_lock_class);
> -
> - irq_set_chip_and_handler(i, &ct->chip, ct->handler);
> - irq_set_chip_data(i, gc);
> - irq_modify_status(i, clr, set);
> + irq_gc_setup_irq(gc, i);
> + irq_get_irq_data(i)->hwirq = i - gc->irq_base;
> }
> gc->irq_cnt = i - gc->irq_base;
> }
> EXPORT_SYMBOL_GPL(irq_setup_generic_chip);
>
> +#ifdef CONFIG_IRQ_DOMAIN
> +static int irq_gc_irq_domain_map(struct irq_domain *d, unsigned int irq,
> + irq_hw_number_t hw)
> +{
> + struct irq_chip_generic **gc_array = d->host_data;
> + struct irq_chip_generic *gc = gc_array[hw / 32];
> +
This .map callback gets already called in irq_domain_add_legacy(),
where gc_array has not been populated yet with the implementation
below ...

> + /* We need a valid irq number for suspend/resume functions */
> + if ((int)gc->irq_base == -1)
> + gc->irq_base = irq;
> + irq_gc_setup_irq(gc, irq);
> + return 0;
> +}
> +
> +static struct irq_domain_ops irq_gc_irq_domain_ops = {
> + .map = irq_gc_irq_domain_map,
> + .xlate = irq_domain_xlate_onetwocell,
> +};
> +
> +/*
> + * irq_setup_generic_chip_domain - Setup a domain and N generic chips
> + * @name: Name of the irq chip
> + * @node: Device tree node pointer for domain
> + * @num_ct: Number of irq_chip_type instances associated with this
> + * @irq_base: Interrupt base nr for this chip
> + * @reg_base: Register base address (virtual)
> + * @handler: Default flow handler associated with this chip
> + * @hwirq_cnt: Number of hw irqs for the domain
> + * @flags: Flags for initialization
> + * @clr: IRQ_* bits to clear
> + * @set: IRQ_* bits to set
> + * @gc_init_cb: Init callback function called for each generic irq chip created
> + * @private Ptr to caller private data
> + *
> + * Set up an irq domain and N banks of 32 interrupts starting from gc->irq_base.
> + * Note, this initializes all interrupts to the primary irq_chip_type and its
> + * associated handler.
> + */
> +int irq_setup_generic_chip_domain(const char *name, struct device_node *node,
> + int num_ct, unsigned int irq_base,
> + void __iomem *reg_base,
> + irq_flow_handler_t handler, u32 hwirq_cnt,
> + enum irq_gc_flags flags, unsigned int clr,
> + unsigned int set,
> + void (*gc_init_cb)(struct irq_chip_generic *),
> + void *private)
> +{
> + int ret, i;
> + u32 msk = 0;
> + struct irq_chip_generic **gc;
> + struct irq_domain *d;
> + int num_gc = (hwirq_cnt + 31) / 32;
> +
> + gc = kzalloc(num_gc * sizeof(struct irq_chip_generic *), GFP_KERNEL);
> + if (!gc)
> + return -ENOMEM;
> +
> + if (node)
> + d = irq_domain_add_linear(node, hwirq_cnt, &irq_gc_irq_domain_ops, gc);
> + else {
> + msk = IRQ_MSK(32);
> + d = irq_domain_add_legacy(node, hwirq_cnt, irq_base, 0,
> + &irq_gc_irq_domain_ops, gc);
> + }
> +
... irq_domain_add_legacy() is called here for !node case ...

> + for (i = 0; i < num_gc; i++) {
> + gc[i] = irq_alloc_generic_chip(name, num_ct, irq_base,
> + reg_base, handler);

... while gc[i] only gets populated here ...

The following change seems fixing the problem for me.

8<---
@@ -323,6 +324,7 @@ int irq_setup_generic_chip_domain(const char *name, struct device_node *node,
void *private)
{
int ret, i;
+ unsigned int irqbase = irq_base;
u32 msk = 0;
struct irq_chip_generic **gc;
struct irq_domain *d;
@@ -332,16 +334,8 @@ int irq_setup_generic_chip_domain(const char *name, struct device_node *node,
if (!gc)
return -ENOMEM;

- if (node)
- d = irq_domain_add_linear(node, hwirq_cnt, &irq_gc_irq_domain_ops, gc);
- else {
- msk = IRQ_MSK(32);
- d = irq_domain_add_legacy(node, hwirq_cnt, irq_base, 0,
- &irq_gc_irq_domain_ops, gc);
- }
-
for (i = 0; i < num_gc; i++) {
- gc[i] = irq_alloc_generic_chip(name, num_ct, irq_base,
+ gc[i] = irq_alloc_generic_chip(name, num_ct, irqbase,
reg_base, handler);
if (!gc[i]) {
ret = -ENOMEM;
@@ -355,7 +349,15 @@ int irq_setup_generic_chip_domain(const char *name, struct device_node *node,

irq_setup_generic_chip(gc[i], msk, flags, clr, set);

- irq_base += node ? 0 : 32;
+ irqbase += node ? 0 : 32;
+ }
+
+ if (node)
+ d = irq_domain_add_linear(node, hwirq_cnt, &irq_gc_irq_domain_ops, gc);
+ else {
+ msk = IRQ_MSK(32);
+ d = irq_domain_add_legacy(node, hwirq_cnt, irq_base, 0,
+ &irq_gc_irq_domain_ops, gc);
}

return 0;
--->8

Regards,
Shawn

> + if (!gc[i]) {
> + ret = -ENOMEM;
> + goto err;
> + }
> + gc[i]->hwirq_base = i * 32;
> + gc[i]->domain = d;
> + gc[i]->private = private;
> +
> + gc_init_cb(gc[i]);
> +
> + irq_setup_generic_chip(gc[i], msk, flags, clr, set);
> +
> + irq_base += node ? 0 : 32;
> + }
> +
> + return 0;
> +
> + err:
> + for ( ; i >= 0; i--)
> + kfree(gc[i]);
> + kfree(gc);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(irq_setup_generic_chip_domain);
> +#endif
> +
> /**
> * irq_setup_alt_chip - Switch to alternative chip
> * @d: irq_data for this interrupt
> @@ -324,9 +431,10 @@ static int irq_gc_suspend(void)
>
> list_for_each_entry(gc, &gc_list, list) {
> struct irq_chip_type *ct = gc->chip_types;
> + struct irq_data *data = irq_get_irq_data(gc->irq_base);
>
> - if (ct->chip.irq_suspend)
> - ct->chip.irq_suspend(irq_get_irq_data(gc->irq_base));
> + if (ct->chip.irq_suspend && data)
> + ct->chip.irq_suspend(data);
> }
> return 0;
> }
> @@ -337,9 +445,10 @@ static void irq_gc_resume(void)
>
> list_for_each_entry(gc, &gc_list, list) {
> struct irq_chip_type *ct = gc->chip_types;
> + struct irq_data *data = irq_get_irq_data(gc->irq_base);
>
> - if (ct->chip.irq_resume)
> - ct->chip.irq_resume(irq_get_irq_data(gc->irq_base));
> + if (ct->chip.irq_resume && data)
> + ct->chip.irq_resume(data);
> }
> }
> #else
> @@ -353,9 +462,10 @@ static void irq_gc_shutdown(void)
>
> list_for_each_entry(gc, &gc_list, list) {
> struct irq_chip_type *ct = gc->chip_types;
> + struct irq_data *data = irq_get_irq_data(gc->irq_base);
>
> - if (ct->chip.irq_pm_shutdown)
> - ct->chip.irq_pm_shutdown(irq_get_irq_data(gc->irq_base));
> + if (ct->chip.irq_pm_shutdown && data)
> + ct->chip.irq_pm_shutdown(data);
> }
> }
>
> --
> 1.7.5.4
>
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