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

[Grant Likely <grant.likely@secretlab.ca>]

On Fri, Feb 3, 2012 at 3:35 PM, Rob Herring <robherring2@gmail.com> wrote:
> From: Rob Herring <rob.herring@calxeda.com>
>
> 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@calxeda.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
>  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;

Shouldn't this be: 1 << (d->hwirq & 32)?  The way it is written will
result in mask == 0 for all 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];
> +
> +       /* 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,

Can we hard-enforce _xlate_twocell here?  Are there any users using
just one cell?  Alternately, can we make the caller specify if one or
two cells are expected?

The irq_domain_ops structure should be const.

> +};
> +
> +/*
> + * 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;

Use the ALIGN() macro.

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



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.