diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/sh/intc/virq.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/sh/intc/virq.c b/drivers/sh/intc/virq.c new file mode 100644 index 000000000..a638c3048 --- /dev/null +++ b/drivers/sh/intc/virq.c @@ -0,0 +1,269 @@ +/* + * Support for virtual IRQ subgroups. + * + * Copyright (C) 2010 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#define pr_fmt(fmt) "intc: " fmt + +#include <linux/slab.h> +#include <linux/irq.h> +#include <linux/list.h> +#include <linux/radix-tree.h> +#include <linux/spinlock.h> +#include <linux/export.h> +#include "internals.h" + +static struct intc_map_entry intc_irq_xlate[INTC_NR_IRQS]; + +struct intc_virq_list { + unsigned int irq; + struct intc_virq_list *next; +}; + +#define for_each_virq(entry, head) \ + for (entry = head; entry; entry = entry->next) + +/* + * Tags for the radix tree + */ +#define INTC_TAG_VIRQ_NEEDS_ALLOC 0 + +void intc_irq_xlate_set(unsigned int irq, intc_enum id, struct intc_desc_int *d) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&intc_big_lock, flags); + intc_irq_xlate[irq].enum_id = id; + intc_irq_xlate[irq].desc = d; + raw_spin_unlock_irqrestore(&intc_big_lock, flags); +} + +struct intc_map_entry *intc_irq_xlate_get(unsigned int irq) +{ + return intc_irq_xlate + irq; +} + +int intc_irq_lookup(const char *chipname, intc_enum enum_id) +{ + struct intc_map_entry *ptr; + struct intc_desc_int *d; + int irq = -1; + + list_for_each_entry(d, &intc_list, list) { + int tagged; + + if (strcmp(d->chip.name, chipname) != 0) + continue; + + /* + * Catch early lookups for subgroup VIRQs that have not + * yet been allocated an IRQ. This already includes a + * fast-path out if the tree is untagged, so there is no + * need to explicitly test the root tree. + */ + tagged = radix_tree_tag_get(&d->tree, enum_id, + INTC_TAG_VIRQ_NEEDS_ALLOC); + if (unlikely(tagged)) + break; + + 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 int add_virq_to_pirq(unsigned int irq, unsigned int virq) +{ + struct intc_virq_list *entry; + struct intc_virq_list **last = NULL; + + /* scan for duplicates */ + for_each_virq(entry, irq_get_handler_data(irq)) { + if (entry->irq == virq) + return 0; + last = &entry->next; + } + + entry = kzalloc(sizeof(struct intc_virq_list), GFP_ATOMIC); + if (!entry) + return -ENOMEM; + + entry->irq = virq; + + if (last) + *last = entry; + else + irq_set_handler_data(irq, entry); + + return 0; +} + +static void intc_virq_handler(struct irq_desc *desc) +{ + unsigned int irq = irq_desc_get_irq(desc); + struct irq_data *data = irq_desc_get_irq_data(desc); + struct irq_chip *chip = irq_data_get_irq_chip(data); + struct intc_virq_list *entry, *vlist = irq_data_get_irq_handler_data(data); + struct intc_desc_int *d = get_intc_desc(irq); + + chip->irq_mask_ack(data); + + for_each_virq(entry, vlist) { + unsigned long addr, handle; + struct irq_desc *vdesc = irq_to_desc(entry->irq); + + if (vdesc) { + handle = (unsigned long)irq_desc_get_handler_data(vdesc); + addr = INTC_REG(d, _INTC_ADDR_E(handle), 0); + if (intc_reg_fns[_INTC_FN(handle)](addr, handle, 0)) + generic_handle_irq_desc(vdesc); + } + } + + chip->irq_unmask(data); +} + +static unsigned long __init intc_subgroup_data(struct intc_subgroup *subgroup, + struct intc_desc_int *d, + unsigned int index) +{ + unsigned int fn = REG_FN_TEST_BASE + (subgroup->reg_width >> 3) - 1; + + return _INTC_MK(fn, MODE_ENABLE_REG, intc_get_reg(d, subgroup->reg), + 0, 1, (subgroup->reg_width - 1) - index); +} + +static void __init intc_subgroup_init_one(struct intc_desc *desc, + struct intc_desc_int *d, + struct intc_subgroup *subgroup) +{ + struct intc_map_entry *mapped; + unsigned int pirq; + unsigned long flags; + int i; + + mapped = radix_tree_lookup(&d->tree, subgroup->parent_id); + if (!mapped) { + WARN_ON(1); + return; + } + + pirq = mapped - intc_irq_xlate; + + raw_spin_lock_irqsave(&d->lock, flags); + + for (i = 0; i < ARRAY_SIZE(subgroup->enum_ids); i++) { + struct intc_subgroup_entry *entry; + int err; + + if (!subgroup->enum_ids[i]) + continue; + + entry = kmalloc(sizeof(*entry), GFP_NOWAIT); + if (!entry) + break; + + entry->pirq = pirq; + entry->enum_id = subgroup->enum_ids[i]; + entry->handle = intc_subgroup_data(subgroup, d, i); + + err = radix_tree_insert(&d->tree, entry->enum_id, entry); + if (unlikely(err < 0)) + break; + + radix_tree_tag_set(&d->tree, entry->enum_id, + INTC_TAG_VIRQ_NEEDS_ALLOC); + } + + raw_spin_unlock_irqrestore(&d->lock, flags); +} + +void __init intc_subgroup_init(struct intc_desc *desc, struct intc_desc_int *d) +{ + int i; + + if (!desc->hw.subgroups) + return; + + for (i = 0; i < desc->hw.nr_subgroups; i++) + intc_subgroup_init_one(desc, d, desc->hw.subgroups + i); +} + +static void __init intc_subgroup_map(struct intc_desc_int *d) +{ + struct intc_subgroup_entry *entries[32]; + unsigned long flags; + unsigned int nr_found; + int i; + + raw_spin_lock_irqsave(&d->lock, flags); + +restart: + nr_found = radix_tree_gang_lookup_tag_slot(&d->tree, + (void ***)entries, 0, ARRAY_SIZE(entries), + INTC_TAG_VIRQ_NEEDS_ALLOC); + + for (i = 0; i < nr_found; i++) { + struct intc_subgroup_entry *entry; + int irq; + + entry = radix_tree_deref_slot((void **)entries[i]); + if (unlikely(!entry)) + continue; + if (radix_tree_deref_retry(entry)) + goto restart; + + irq = irq_alloc_desc(numa_node_id()); + if (unlikely(irq < 0)) { + pr_err("no more free IRQs, bailing..\n"); + break; + } + + activate_irq(irq); + + pr_info("Setting up a chained VIRQ from %d -> %d\n", + irq, entry->pirq); + + intc_irq_xlate_set(irq, entry->enum_id, d); + + irq_set_chip_and_handler_name(irq, irq_get_chip(entry->pirq), + handle_simple_irq, "virq"); + irq_set_chip_data(irq, irq_get_chip_data(entry->pirq)); + + irq_set_handler_data(irq, (void *)entry->handle); + + /* + * Set the virtual IRQ as non-threadable. + */ + irq_set_nothread(irq); + + /* Set handler data before installing the handler */ + add_virq_to_pirq(entry->pirq, irq); + irq_set_chained_handler(entry->pirq, intc_virq_handler); + + radix_tree_tag_clear(&d->tree, entry->enum_id, + INTC_TAG_VIRQ_NEEDS_ALLOC); + radix_tree_replace_slot(&d->tree, (void **)entries[i], + &intc_irq_xlate[irq]); + } + + raw_spin_unlock_irqrestore(&d->lock, flags); +} + +void __init intc_finalize(void) +{ + struct intc_desc_int *d; + + list_for_each_entry(d, &intc_list, list) + if (radix_tree_tagged(&d->tree, INTC_TAG_VIRQ_NEEDS_ALLOC)) + intc_subgroup_map(d); +} |