sh: intc: Implement reverse mapping for IRQs to per-controller IDs.

This implements a scheme roughly analogous to the PowerPC virtual to
hardware IRQ mapping, which we use for IRQ to per-controller ID mapping.
This makes it possible for drivers to use the IDs directly for lookup
instead of hardcoding the vector.

The main motivation for this work is as a building block for dynamically
allocating virtual IRQs for demuxing INTC events sharing a single INTEVT
in addition to a common masking source.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2010-09-23 20:09:38 +09:00
parent e8184a47c9
commit 44629f57ac
3 changed files with 100 additions and 1 deletions

View File

@ -22,3 +22,12 @@ config INTC_BALANCING
vectors.
If in doubt, say N.
config INTC_MAPPING_DEBUG
bool "Expose IRQ to per-controller id mapping via debugfs"
depends on DEBUG_FS
help
This will create a debugfs entry for showing the relationship
between system IRQs and the per-controller id tables.
If in doubt, say N.

View File

@ -30,6 +30,11 @@
#include <linux/topology.h>
#include <linux/bitmap.h>
#include <linux/cpumask.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/radix-tree.h>
#include <linux/mutex.h>
#include <asm/sizes.h>
#define _INTC_MK(fn, mode, addr_e, addr_d, width, shift) \
@ -54,9 +59,15 @@ struct intc_window {
unsigned long size;
};
struct intc_map_entry {
intc_enum enum_id;
struct intc_desc_int *desc;
};
struct intc_desc_int {
struct list_head list;
struct sys_device sysdev;
struct radix_tree_root tree;
pm_message_t state;
unsigned long *reg;
#ifdef CONFIG_SMP
@ -86,7 +97,9 @@ static LIST_HEAD(intc_list);
* unused irq_desc positions in the sparse array.
*/
static DECLARE_BITMAP(intc_irq_map, NR_IRQS);
static struct intc_map_entry intc_irq_xlate[NR_IRQS];
static DEFINE_SPINLOCK(vector_lock);
static DEFINE_MUTEX(irq_xlate_mutex);
#ifdef CONFIG_SMP
#define IS_SMP(x) x.smp
@ -828,6 +841,26 @@ static unsigned int __init intc_sense_data(struct intc_desc *desc,
return 0;
}
unsigned int intc_irq_lookup(const char *chipname, intc_enum enum_id)
{
struct intc_map_entry *ptr;
struct intc_desc_int *d;
unsigned int irq = 0;
list_for_each_entry(d, &intc_list, list) {
if (strcmp(d->chip.name, chipname) == 0) {
ptr = radix_tree_lookup(&d->tree, enum_id);
if (ptr) {
irq = ptr - intc_irq_xlate;
break;
}
}
}
return irq;
}
EXPORT_SYMBOL_GPL(intc_irq_lookup);
static void __init intc_register_irq(struct intc_desc *desc,
struct intc_desc_int *d,
intc_enum enum_id,
@ -837,10 +870,15 @@ static void __init intc_register_irq(struct intc_desc *desc,
unsigned int data[2], primary;
/*
* Register the IRQ position with the global IRQ map
* Register the IRQ position with the global IRQ map, then insert
* it in to the radix tree.
*/
set_bit(irq, intc_irq_map);
mutex_lock(&irq_xlate_mutex);
radix_tree_insert(&d->tree, enum_id, &intc_irq_xlate[irq]);
mutex_unlock(&irq_xlate_mutex);
/*
* Prefer single interrupt source bitmap over other combinations:
*
@ -1082,6 +1120,9 @@ int __init register_intc_controller(struct intc_desc *desc)
continue;
}
intc_irq_xlate[irq].enum_id = vect->enum_id;
intc_irq_xlate[irq].desc = d;
intc_register_irq(desc, d, vect->enum_id, irq);
for (k = i + 1; k < hw->nr_vectors; k++) {
@ -1196,6 +1237,54 @@ static SYSDEV_CLASS_ATTR(userimask, S_IRUSR | S_IWUSR,
show_intc_userimask, store_intc_userimask);
#endif
#ifdef CONFIG_INTC_MAPPING_DEBUG
static int intc_irq_xlate_debug(struct seq_file *m, void *priv)
{
int i;
seq_printf(m, "%-5s %-7s %-15s\n", "irq", "enum", "chip name");
for (i = 1; i < nr_irqs; i++) {
struct intc_desc_int *desc = intc_irq_xlate[i].desc;
if (!desc)
continue;
seq_printf(m, "%5d ", i);
seq_printf(m, "0x%05x ", intc_irq_xlate[i].enum_id);
seq_printf(m, "%-15s\n", desc->chip.name);
}
return 0;
}
static int intc_irq_xlate_open(struct inode *inode, struct file *file)
{
return single_open(file, intc_irq_xlate_debug, inode->i_private);
}
static const struct file_operations intc_irq_xlate_fops = {
.open = intc_irq_xlate_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init intc_irq_xlate_init(void)
{
/*
* XXX.. use arch_debugfs_dir here when all of the intc users are
* converted.
*/
if (debugfs_create_file("intc_irq_xlate", S_IRUGO, NULL, NULL,
&intc_irq_xlate_fops) == NULL)
return -ENOMEM;
return 0;
}
fs_initcall(intc_irq_xlate_init);
#endif
static ssize_t
show_intc_name(struct sys_device *dev, struct sysdev_attribute *attr, char *buf)
{

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@ -108,6 +108,7 @@ struct intc_desc symbol __initdata = { \
int __init register_intc_controller(struct intc_desc *desc);
void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs);
int intc_set_priority(unsigned int irq, unsigned int prio);
unsigned int intc_irq_lookup(const char *chipname, intc_enum enum_id);
#ifdef CONFIG_INTC_USERIMASK
int register_intc_userimask(unsigned long addr);