Commit 44629f57 authored by Paul Mundt's avatar Paul Mundt
Browse files

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: default avatarPaul Mundt <lethal@linux-sh.org>
parent e8184a47

drivers/sh/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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.

drivers/sh/intc.c

+90 −1
Original line number Diff line number Diff line
@@ -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)

{

include/linux/sh_intc.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

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