[RFC patch 7/8] genirq: generic chip: Add linear irq domain support

From: Thomas Gleixner
Date: Fri May 03 2013 - 17:51:22 EST


Provide infrastructure for irq chip implementations which work on
linear irq domains.

- Interface to allocate multiple generic chips which are associated to
the irq domain.

- Interface to get the generic chip pointer for a particular hardware
interrupt in the domain.

- irq domain mapping function to install the chip for a particular
interrupt.

Note: This lacks a removal function for now, but this is a draft patch
the ARM folks to work on.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/irq.h | 30 +++++++
include/linux/irqdomain.h | 12 +++
kernel/irq/generic-chip.c | 179 ++++++++++++++++++++++++++++++++++++++++++++--
kernel/irq/irqdomain.c | 6 -
4 files changed, 215 insertions(+), 12 deletions(-)

Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -678,6 +678,8 @@ struct irq_chip_type {
* @wake_active: Interrupt is marked as an wakeup from suspend source
* @num_ct: Number of available irq_chip_type instances (usually 1)
* @private: Private data for non generic chip callbacks
+ * @installed: bitfield to denote installed interrupts
+ * @domain: irq domain pointer
* @list: List head for keeping track of instances
* @chip_types: Array of interrupt irq_chip_types
*
@@ -699,6 +701,8 @@ struct irq_chip_generic {
u32 wake_active;
unsigned int num_ct;
void *private;
+ unsigned long installed;
+ struct irq_domain *domain;
struct list_head list;
struct irq_chip_type chip_types[0];
};
@@ -719,6 +723,24 @@ enum irq_gc_flags {
IRQ_GC_NO_MASK = 1 << 3,
};

+/*
+ * struct irq_domain_chip_generic - Generic irq chip data structure for irq domains
+ * @irqs_per_chip: Number of interrupts per chip
+ * @num_chips: Number of chips
+ * @irq_flags_to_set: IRQ* flags to set on irq setup
+ * @irq_flags_to_clear: IRQ* flags to clear on irq setup
+ * @gc_flags: Generic chip specific setup flags
+ * @gc: Array of generic interrupt chips
+ */
+struct irq_domain_chip_generic {
+ unsigned int irqs_per_chip;
+ unsigned int num_chips;
+ unsigned int irq_flags_to_clear;
+ unsigned int irq_flags_to_set;
+ enum irq_gc_flags gc_flags;
+ struct irq_chip_generic gc[0];
+};
+
/* Generic chip callback functions */
void irq_gc_noop(struct irq_data *d);
void irq_gc_mask_disable_reg(struct irq_data *d);
@@ -742,6 +764,14 @@ int irq_setup_alt_chip(struct irq_data *
void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
unsigned int clr, unsigned int set);

+struct irq_chip_generic *irq_get_domain_generic_chip(struct irq_domain *d, unsigned int hw_irq);
+int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
+ int num_ct, const char *name,
+ irq_flow_handler_t handler,
+ unsigned int clr, unsigned int set,
+ enum irq_gc_flags flags);
+
+
static inline struct irq_chip_type *irq_data_get_chip_type(struct irq_data *d)
{
return container_of(d->chip, struct irq_chip_type, chip);
Index: linux-2.6/include/linux/irqdomain.h
===================================================================
--- linux-2.6.orig/include/linux/irqdomain.h
+++ linux-2.6/include/linux/irqdomain.h
@@ -66,6 +66,10 @@ struct irq_domain_ops {
unsigned long *out_hwirq, unsigned int *out_type);
};

+extern struct irq_domain_ops irq_generic_chip_ops;
+
+struct irq_domain_chip_generic;
+
/**
* struct irq_domain - Hardware interrupt number translation object
* @link: Element in global irq_domain list.
@@ -109,8 +113,16 @@ struct irq_domain {

/* Optional device node pointer */
struct device_node *of_node;
+ /* Optional pointer to generic interrupt chips */
+ struct irq_domain_chip_generic *gc;
};

+#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
+ * ie. legacy 8259, gets irqs 1..15 */
+#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
+#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
+#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
+
#ifdef CONFIG_IRQ_DOMAIN
struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
unsigned int size,
Index: linux-2.6/kernel/irq/generic-chip.c
===================================================================
--- linux-2.6.orig/kernel/irq/generic-chip.c
+++ linux-2.6/kernel/irq/generic-chip.c
@@ -7,6 +7,7 @@
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/syscore_ops.h>
@@ -226,6 +227,84 @@ irq_alloc_generic_chip(const char *name,
}
EXPORT_SYMBOL_GPL(irq_alloc_generic_chip);

+/**
+ * irq_alloc_domain_generic_chip - Allocate generic chips for an irq domain
+ * @d: irq domain for which to allocate chips
+ * @irqs_per_chip: Number of interrupts each chip handles
+ * @num_ct: Number of irq_chip_type instances associated with this
+ * @name: Name of the irq chip
+ * @handler: Default flow handler associated with these chips
+ * @clr: IRQ_* bits to clear in the mapping function
+ * @set: IRQ_* bits to set in the mapping function
+ */
+int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
+ int num_ct, const char *name,
+ irq_flow_handler_t handler,
+ unsigned int clr, unsigned int set,
+ enum irq_gc_flags gcflags)
+{
+ struct irq_domain_chip_generic *dgc;
+ struct irq_chip_generic *gc;
+ int numchips, sz, i;
+ unsigned long flags;
+
+ if (d->gc)
+ return -EBUSY;
+
+ if (d->revmap_type != IRQ_DOMAIN_MAP_LINEAR)
+ return -EINVAL;
+
+ numchips = d->revmap_data.linear.size / irqs_per_chip;
+ if (!numchips)
+ return -EINVAL;
+
+ sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
+ sz *= numchips;
+ sz += sizeof(*dgc);
+
+ dgc = kzalloc(sz, GFP_KERNEL);
+ if (!dgc)
+ return -ENOMEM;
+ dgc->irqs_per_chip = irqs_per_chip;
+ dgc->num_chips = numchips;
+ dgc->irq_flags_to_set = set;
+ dgc->irq_flags_to_clear = clr;
+ dgc->gc_flags = gcflags;
+ gc = dgc->gc;
+
+ for (i = 0; i < numchips; i++, gc++) {
+ irq_init_generic_chip(gc, name, num_ct, i * irqs_per_chip,
+ NULL, handler);
+ gc->domain = d;
+ raw_spin_lock_irqsave(&gc_lock, flags);
+ list_add_tail(&gc->list, &gc_list);
+ raw_spin_unlock_irqrestore(&gc_lock, flags);
+ }
+ d->gc = dgc;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(irq_alloc_domain_generic_chips);
+
+/**
+ * irq_get_domain_generic_chip - Get a pointer to the generic chip of a hw_irq
+ * @d: irq domain pointer
+ * @hw_irq: Hardware interrupt number
+ */
+struct irq_chip_generic *
+irq_get_domain_generic_chip(struct irq_domain *d, unsigned int hw_irq)
+{
+ struct irq_domain_chip_generic *dgc = d->gc;
+ int idx;
+
+ if (!dgc)
+ return NULL;
+ idx = hw_irq / dgc->irqs_per_chip;
+ if (idx >= dgc->num_chips)
+ return NULL;
+ return &dgc->gc[idx];
+}
+EXPORT_SYMBOL_GPL(irq_get_domain_generic_chip);
+
/*
* Separate lockdep class for interrupt chip which can nest irq_desc
* lock.
@@ -233,6 +312,64 @@ EXPORT_SYMBOL_GPL(irq_alloc_generic_chip
static struct lock_class_key irq_nested_lock_class;

/**
+ * irq_map_generic_chip - Map a generic chip for an irq domain
+ */
+static int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
+ irq_hw_number_t hw_irq)
+{
+ struct irq_data *data = irq_get_irq_data(virq);
+ struct irq_domain_chip_generic *dgc = d->gc;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ struct irq_chip *chip;
+ unsigned long flags;
+ int idx;
+
+ if (!d->gc)
+ return -ENODEV;
+
+ idx = hw_irq / dgc->irqs_per_chip;
+ if (idx >= dgc->num_chips)
+ return -EINVAL;
+ gc = &dgc->gc[idx];
+
+ idx = hw_irq % dgc->irqs_per_chip;
+
+ if (test_bit(idx, &gc->installed))
+ return -EBUSY;
+
+ set_bit(idx, &gc->installed);
+ ct = gc->chip_types;
+ chip = &ct->chip;
+
+ /* Init mask cache ? */
+ if (dgc->gc_flags & IRQ_GC_INIT_MASK_CACHE) {
+ raw_spin_lock_irqsave(&gc->lock, flags);
+ gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask);
+ raw_spin_unlock_irqrestore(&gc->lock, flags);
+ }
+
+ if (dgc->gc_flags & IRQ_GC_INIT_NESTED_LOCK)
+ irq_set_lockdep_class(virq, &irq_nested_lock_class);
+
+ if (chip->irq_calc_mask)
+ chip->irq_calc_mask(data);
+ else
+ data->mask = 1 << idx;
+
+ irq_set_chip_and_handler(virq, chip, ct->handler);
+ irq_set_chip_data(virq, gc);
+ irq_modify_status(virq, dgc->irq_flags_to_clear, dgc->irq_flags_to_set);
+ return 0;
+}
+
+struct irq_domain_ops irq_generic_chip_ops = {
+ .map = irq_map_generic_chip,
+ .xlate = irq_domain_xlate_onecell,
+};
+EXPORT_SYMBOL_GPL(irq_generic_chip_ops);
+
+/**
* irq_setup_generic_chip - Setup a range of interrupts with a generic chip
* @gc: Generic irq chip holding all data
* @msk: Bitmask holding the irqs to initialize relative to gc->irq_base
@@ -345,6 +482,24 @@ void irq_remove_generic_chip(struct irq_
}
EXPORT_SYMBOL_GPL(irq_remove_generic_chip);

+static struct irq_data *irq_gc_get_irq_data(struct irq_chip_generic *gc)
+{
+ unsigned int virq;
+
+ if (!gc->domain)
+ return irq_get_irq_data(gc->irq_base);
+
+ /*
+ * We don't know which of the irqs has been actually
+ * installed. Use the first one.
+ */
+ if (!gc->installed)
+ return NULL;
+
+ virq = irq_find_mapping(gc->domain, gc->irq_base + __ffs(gc->installed));
+ return virq ? irq_get_irq_data(virq) : NULL;
+}
+
#ifdef CONFIG_PM
static int irq_gc_suspend(void)
{
@@ -353,8 +508,12 @@ static int irq_gc_suspend(void)
list_for_each_entry(gc, &gc_list, list) {
struct irq_chip_type *ct = gc->chip_types;

- if (ct->chip.irq_suspend)
- ct->chip.irq_suspend(irq_get_irq_data(gc->irq_base));
+ if (ct->chip.irq_suspend) {
+ struct irq_data *data = irq_gc_get_irq_data(gc);
+
+ if (data)
+ ct->chip.irq_suspend(data);
+ }
}
return 0;
}
@@ -366,8 +525,12 @@ static void irq_gc_resume(void)
list_for_each_entry(gc, &gc_list, list) {
struct irq_chip_type *ct = gc->chip_types;

- if (ct->chip.irq_resume)
- ct->chip.irq_resume(irq_get_irq_data(gc->irq_base));
+ if (ct->chip.irq_resume) {
+ struct irq_data *data = irq_gc_get_irq_data(gc);
+
+ if (data)
+ ct->chip.irq_resume(data);
+ }
}
}
#else
@@ -382,8 +545,12 @@ static void irq_gc_shutdown(void)
list_for_each_entry(gc, &gc_list, list) {
struct irq_chip_type *ct = gc->chip_types;

- if (ct->chip.irq_pm_shutdown)
- ct->chip.irq_pm_shutdown(irq_get_irq_data(gc->irq_base));
+ if (ct->chip.irq_pm_shutdown) {
+ struct irq_data *data = irq_gc_get_irq_data(gc);
+
+ if (data)
+ ct->chip.irq_pm_shutdown(data);
+ }
}
}

Index: linux-2.6/kernel/irq/irqdomain.c
===================================================================
--- linux-2.6.orig/kernel/irq/irqdomain.c
+++ linux-2.6/kernel/irq/irqdomain.c
@@ -16,12 +16,6 @@
#include <linux/smp.h>
#include <linux/fs.h>

-#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
- * ie. legacy 8259, gets irqs 1..15 */
-#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
-#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
-#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
-
static LIST_HEAD(irq_domain_list);
static DEFINE_MUTEX(irq_domain_mutex);



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/