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authorPaul Mundt <lethal@linux-sh.org>2010-09-23 20:09:38 +0900
committerPaul Mundt <lethal@linux-sh.org>2010-10-05 01:15:47 +0900
commit44629f57accccbb8e6d443246fe6f51b42f7f781 (patch)
treeb75bab4a39a2be40f58a9d6daac4a208035300fe /drivers
parente8184a47c9cc04380553114815356d1042a27788 (diff)
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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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/sh/Kconfig9
-rw-r--r--drivers/sh/intc.c91
2 files changed, 99 insertions, 1 deletions
diff --git a/drivers/sh/Kconfig b/drivers/sh/Kconfig
index 1dc8b7a..e01ae42 100644
--- a/drivers/sh/Kconfig
+++ b/drivers/sh/Kconfig
@@ -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.
diff --git a/drivers/sh/intc.c b/drivers/sh/intc.c
index 4e01d65..a27dcb4 100644
--- a/drivers/sh/intc.c
+++ b/drivers/sh/intc.c
@@ -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)
{