/* * 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); }