diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/irqdomain.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 509adb8762d..f551bc1d316 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1,14 +1,612 @@ +#include <linux/debugfs.h> +#include <linux/hardirq.h> +#include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/irqdesc.h> #include <linux/irqdomain.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/seq_file.h> #include <linux/slab.h> +#include <linux/smp.h> +#include <linux/fs.h> static LIST_HEAD(irq_domain_list); static DEFINE_MUTEX(irq_domain_mutex); +#ifdef CONFIG_PPC +static DEFINE_MUTEX(revmap_trees_mutex); +static unsigned int irq_virq_count = NR_IRQS; +static struct irq_domain *irq_default_host; + +static int default_irq_host_match(struct irq_domain *h, struct device_node *np) +{ + return h->of_node != NULL && h->of_node == np; +} + +/** + * irq_alloc_host() - Allocate a new irq_domain data structure + * @of_node: optional device-tree node of the interrupt controller + * @revmap_type: type of reverse mapping to use + * @revmap_arg: for IRQ_DOMAIN_MAP_LINEAR linear only: size of the map + * @ops: map/unmap host callbacks + * @inval_irq: provide a hw number in that host space that is always invalid + * + * Allocates and initialize and irq_domain structure. Note that in the case of + * IRQ_DOMAIN_MAP_LEGACY, the map() callback will be called before this returns + * for all legacy interrupts except 0 (which is always the invalid irq for + * a legacy controller). For a IRQ_DOMAIN_MAP_LINEAR, the map is allocated by + * this call as well. For a IRQ_DOMAIN_MAP_TREE, the radix tree will be + * allocated later during boot automatically (the reverse mapping will use the + * slow path until that happens). + */ +struct irq_domain *irq_alloc_host(struct device_node *of_node, + unsigned int revmap_type, + unsigned int revmap_arg, + struct irq_domain_ops *ops, + irq_hw_number_t inval_irq) +{ + struct irq_domain *host, *h; + unsigned int size = sizeof(struct irq_domain); + unsigned int i; + unsigned int *rmap; + + /* Allocate structure and revmap table if using linear mapping */ + if (revmap_type == IRQ_DOMAIN_MAP_LINEAR) + size += revmap_arg * sizeof(unsigned int); + host = kzalloc(size, GFP_KERNEL); + if (host == NULL) + return NULL; + + /* Fill structure */ + host->revmap_type = revmap_type; + host->inval_irq = inval_irq; + host->ops = ops; + host->of_node = of_node_get(of_node); + + if (host->ops->match == NULL) + host->ops->match = default_irq_host_match; + + mutex_lock(&irq_domain_mutex); + /* Make sure only one legacy controller can be created */ + if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) { + list_for_each_entry(h, &irq_domain_list, link) { + if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) { + mutex_unlock(&irq_domain_mutex); + of_node_put(host->of_node); + kfree(host); + return NULL; + } + } + } + list_add(&host->link, &irq_domain_list); + mutex_unlock(&irq_domain_mutex); + + /* Additional setups per revmap type */ + switch(revmap_type) { + case IRQ_DOMAIN_MAP_LEGACY: + /* 0 is always the invalid number for legacy */ + host->inval_irq = 0; + /* setup us as the host for all legacy interrupts */ + for (i = 1; i < NUM_ISA_INTERRUPTS; i++) { + struct irq_data *irq_data = irq_get_irq_data(i); + irq_data->hwirq = i; + irq_data->domain = host; + + /* Legacy flags are left to default at this point, + * one can then use irq_create_mapping() to + * explicitly change them + */ + ops->map(host, i, i); + + /* Clear norequest flags */ + irq_clear_status_flags(i, IRQ_NOREQUEST); + } + break; + case IRQ_DOMAIN_MAP_LINEAR: + rmap = (unsigned int *)(host + 1); + for (i = 0; i < revmap_arg; i++) + rmap[i] = NO_IRQ; + host->revmap_data.linear.size = revmap_arg; + host->revmap_data.linear.revmap = rmap; + break; + case IRQ_DOMAIN_MAP_TREE: + INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL); + break; + default: + break; + } + + pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host); + + return host; +} + +/** + * irq_find_host() - Locates a domain for a given device node + * @node: device-tree node of the interrupt controller + */ +struct irq_domain *irq_find_host(struct device_node *node) +{ + struct irq_domain *h, *found = NULL; + + /* We might want to match the legacy controller last since + * it might potentially be set to match all interrupts in + * the absence of a device node. This isn't a problem so far + * yet though... + */ + mutex_lock(&irq_domain_mutex); + list_for_each_entry(h, &irq_domain_list, link) + if (h->ops->match(h, node)) { + found = h; + break; + } + mutex_unlock(&irq_domain_mutex); + return found; +} +EXPORT_SYMBOL_GPL(irq_find_host); + +/** + * irq_set_default_host() - Set a "default" irq domain + * @host: default host pointer + * + * For convenience, it's possible to set a "default" domain that will be used + * whenever NULL is passed to irq_create_mapping(). It makes life easier for + * platforms that want to manipulate a few hard coded interrupt numbers that + * aren't properly represented in the device-tree. + */ +void irq_set_default_host(struct irq_domain *host) +{ + pr_debug("irq: Default host set to @0x%p\n", host); + + irq_default_host = host; +} + +/** + * irq_set_virq_count() - Set the maximum number of linux irqs + * @count: number of linux irqs, capped with NR_IRQS + * + * This is mainly for use by platforms like iSeries who want to program + * the virtual irq number in the controller to avoid the reverse mapping + */ +void irq_set_virq_count(unsigned int count) +{ + pr_debug("irq: Trying to set virq count to %d\n", count); + + BUG_ON(count < NUM_ISA_INTERRUPTS); + if (count < NR_IRQS) + irq_virq_count = count; +} + +static int irq_setup_virq(struct irq_domain *host, unsigned int virq, + irq_hw_number_t hwirq) +{ + struct irq_data *irq_data = irq_get_irq_data(virq); + + irq_data->hwirq = hwirq; + irq_data->domain = host; + if (host->ops->map(host, virq, hwirq)) { + pr_debug("irq: -> mapping failed, freeing\n"); + irq_data->domain = NULL; + irq_data->hwirq = 0; + return -1; + } + + irq_clear_status_flags(virq, IRQ_NOREQUEST); + + return 0; +} + +/** + * irq_create_direct_mapping() - Allocate an irq for direct mapping + * @host: domain to allocate the irq for or NULL for default host + * + * This routine is used for irq controllers which can choose the hardware + * interrupt numbers they generate. In such a case it's simplest to use + * the linux irq as the hardware interrupt number. + */ +unsigned int irq_create_direct_mapping(struct irq_domain *host) +{ + unsigned int virq; + + if (host == NULL) + host = irq_default_host; + + BUG_ON(host == NULL); + WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP); + + virq = irq_alloc_desc_from(1, 0); + if (virq == NO_IRQ) { + pr_debug("irq: create_direct virq allocation failed\n"); + return NO_IRQ; + } + if (virq >= irq_virq_count) { + pr_err("ERROR: no free irqs available below %i maximum\n", + irq_virq_count); + irq_free_desc(virq); + return 0; + } + + pr_debug("irq: create_direct obtained virq %d\n", virq); + + if (irq_setup_virq(host, virq, virq)) { + irq_free_desc(virq); + return NO_IRQ; + } + + return virq; +} + +/** + * irq_create_mapping() - Map a hardware interrupt into linux irq space + * @host: host owning this hardware interrupt or NULL for default host + * @hwirq: hardware irq number in that host space + * + * Only one mapping per hardware interrupt is permitted. Returns a linux + * irq number. + * If the sense/trigger is to be specified, set_irq_type() should be called + * on the number returned from that call. + */ +unsigned int irq_create_mapping(struct irq_domain *host, + irq_hw_number_t hwirq) +{ + unsigned int virq, hint; + + pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq); + + /* Look for default host if nececssary */ + if (host == NULL) + host = irq_default_host; + if (host == NULL) { + printk(KERN_WARNING "irq_create_mapping called for" + " NULL host, hwirq=%lx\n", hwirq); + WARN_ON(1); + return NO_IRQ; + } + pr_debug("irq: -> using host @%p\n", host); + + /* Check if mapping already exists */ + virq = irq_find_mapping(host, hwirq); + if (virq != NO_IRQ) { + pr_debug("irq: -> existing mapping on virq %d\n", virq); + return virq; + } + + /* Get a virtual interrupt number */ + if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) { + /* Handle legacy */ + virq = (unsigned int)hwirq; + if (virq == 0 || virq >= NUM_ISA_INTERRUPTS) + return NO_IRQ; + return virq; + } else { + /* Allocate a virtual interrupt number */ + hint = hwirq % irq_virq_count; + if (hint == 0) + hint++; + virq = irq_alloc_desc_from(hint, 0); + if (!virq) + virq = irq_alloc_desc_from(1, 0); + if (virq == NO_IRQ) { + pr_debug("irq: -> virq allocation failed\n"); + return NO_IRQ; + } + } + + if (irq_setup_virq(host, virq, hwirq)) { + if (host->revmap_type != IRQ_DOMAIN_MAP_LEGACY) + irq_free_desc(virq); + return NO_IRQ; + } + + pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n", + hwirq, host->of_node ? host->of_node->full_name : "null", virq); + + return virq; +} +EXPORT_SYMBOL_GPL(irq_create_mapping); + +unsigned int irq_create_of_mapping(struct device_node *controller, + const u32 *intspec, unsigned int intsize) +{ + struct irq_domain *host; + irq_hw_number_t hwirq; + unsigned int type = IRQ_TYPE_NONE; + unsigned int virq; + + if (controller == NULL) + host = irq_default_host; + else + host = irq_find_host(controller); + if (host == NULL) { + printk(KERN_WARNING "irq: no irq host found for %s !\n", + controller->full_name); + return NO_IRQ; + } + + /* If host has no translation, then we assume interrupt line */ + if (host->ops->xlate == NULL) + hwirq = intspec[0]; + else { + if (host->ops->xlate(host, controller, intspec, intsize, + &hwirq, &type)) + return NO_IRQ; + } + + /* Create mapping */ + virq = irq_create_mapping(host, hwirq); + if (virq == NO_IRQ) + return virq; + + /* Set type if specified and different than the current one */ + if (type != IRQ_TYPE_NONE && + type != (irqd_get_trigger_type(irq_get_irq_data(virq)))) + irq_set_irq_type(virq, type); + return virq; +} +EXPORT_SYMBOL_GPL(irq_create_of_mapping); + +/** + * irq_dispose_mapping() - Unmap an interrupt + * @virq: linux irq number of the interrupt to unmap + */ +void irq_dispose_mapping(unsigned int virq) +{ + struct irq_data *irq_data = irq_get_irq_data(virq); + struct irq_domain *host; + irq_hw_number_t hwirq; + + if (virq == NO_IRQ || !irq_data) + return; + + host = irq_data->domain; + if (WARN_ON(host == NULL)) + return; + + /* Never unmap legacy interrupts */ + if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) + return; + + irq_set_status_flags(virq, IRQ_NOREQUEST); + + /* remove chip and handler */ + irq_set_chip_and_handler(virq, NULL, NULL); + + /* Make sure it's completed */ + synchronize_irq(virq); + + /* Tell the PIC about it */ + if (host->ops->unmap) + host->ops->unmap(host, virq); + smp_mb(); + + /* Clear reverse map */ + hwirq = irq_data->hwirq; + switch(host->revmap_type) { + case IRQ_DOMAIN_MAP_LINEAR: + if (hwirq < host->revmap_data.linear.size) + host->revmap_data.linear.revmap[hwirq] = NO_IRQ; + break; + case IRQ_DOMAIN_MAP_TREE: + mutex_lock(&revmap_trees_mutex); + radix_tree_delete(&host->revmap_data.tree, hwirq); + mutex_unlock(&revmap_trees_mutex); + break; + } + + /* Destroy map */ + irq_data->hwirq = host->inval_irq; + + irq_free_desc(virq); +} +EXPORT_SYMBOL_GPL(irq_dispose_mapping); + +/** + * irq_find_mapping() - Find a linux irq from an hw irq number. + * @host: domain owning this hardware interrupt + * @hwirq: hardware irq number in that host space + * + * This is a slow path, for use by generic code. It's expected that an + * irq controller implementation directly calls the appropriate low level + * mapping function. + */ +unsigned int irq_find_mapping(struct irq_domain *host, + irq_hw_number_t hwirq) +{ + unsigned int i; + unsigned int hint = hwirq % irq_virq_count; + + /* Look for default host if nececssary */ + if (host == NULL) + host = irq_default_host; + if (host == NULL) + return NO_IRQ; + + /* legacy -> bail early */ + if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) + return hwirq; + + /* Slow path does a linear search of the map */ + if (hint == 0) + hint = 1; + i = hint; + do { + struct irq_data *data = irq_get_irq_data(i); + if (data && (data->domain == host) && (data->hwirq == hwirq)) + return i; + i++; + if (i >= irq_virq_count) + i = 1; + } while(i != hint); + return NO_IRQ; +} +EXPORT_SYMBOL_GPL(irq_find_mapping); + +/** + * irq_radix_revmap_lookup() - Find a linux irq from a hw irq number. + * @host: host owning this hardware interrupt + * @hwirq: hardware irq number in that host space + * + * This is a fast path, for use by irq controller code that uses radix tree + * revmaps + */ +unsigned int irq_radix_revmap_lookup(struct irq_domain *host, + irq_hw_number_t hwirq) +{ + struct irq_data *irq_data; + + if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_TREE)) + return irq_find_mapping(host, hwirq); + + /* + * Freeing an irq can delete nodes along the path to + * do the lookup via call_rcu. + */ + rcu_read_lock(); + irq_data = radix_tree_lookup(&host->revmap_data.tree, hwirq); + rcu_read_unlock(); + + /* + * If found in radix tree, then fine. + * Else fallback to linear lookup - this should not happen in practice + * as it means that we failed to insert the node in the radix tree. + */ + return irq_data ? irq_data->irq : irq_find_mapping(host, hwirq); +} + +/** + * irq_radix_revmap_insert() - Insert a hw irq to linux irq number mapping. + * @host: host owning this hardware interrupt + * @virq: linux irq number + * @hwirq: hardware irq number in that host space + * + * This is for use by irq controllers that use a radix tree reverse + * mapping for fast lookup. + */ +void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq, + irq_hw_number_t hwirq) +{ + struct irq_data *irq_data = irq_get_irq_data(virq); + + if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE)) + return; + + if (virq != NO_IRQ) { + mutex_lock(&revmap_trees_mutex); + radix_tree_insert(&host->revmap_data.tree, hwirq, irq_data); + mutex_unlock(&revmap_trees_mutex); + } +} + +/** + * irq_linear_revmap() - Find a linux irq from a hw irq number. + * @host: host owning this hardware interrupt + * @hwirq: hardware irq number in that host space + * + * This is a fast path, for use by irq controller code that uses linear + * revmaps. It does fallback to the slow path if the revmap doesn't exist + * yet and will create the revmap entry with appropriate locking + */ +unsigned int irq_linear_revmap(struct irq_domain *host, + irq_hw_number_t hwirq) +{ + unsigned int *revmap; + + if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_LINEAR)) + return irq_find_mapping(host, hwirq); + + /* Check revmap bounds */ + if (unlikely(hwirq >= host->revmap_data.linear.size)) + return irq_find_mapping(host, hwirq); + + /* Check if revmap was allocated */ + revmap = host->revmap_data.linear.revmap; + if (unlikely(revmap == NULL)) + return irq_find_mapping(host, hwirq); + + /* Fill up revmap with slow path if no mapping found */ + if (unlikely(revmap[hwirq] == NO_IRQ)) + revmap[hwirq] = irq_find_mapping(host, hwirq); + + return revmap[hwirq]; +} + +#ifdef CONFIG_VIRQ_DEBUG +static int virq_debug_show(struct seq_file *m, void *private) +{ + unsigned long flags; + struct irq_desc *desc; + const char *p; + static const char none[] = "none"; + void *data; + int i; + + seq_printf(m, "%-5s %-7s %-15s %-18s %s\n", "virq", "hwirq", + "chip name", "chip data", "host name"); + + for (i = 1; i < nr_irqs; i++) { + desc = irq_to_desc(i); + if (!desc) + continue; + + raw_spin_lock_irqsave(&desc->lock, flags); + + if (desc->action && desc->action->handler) { + struct irq_chip *chip; + + seq_printf(m, "%5d ", i); + seq_printf(m, "0x%05lx ", desc->irq_data.hwirq); + + chip = irq_desc_get_chip(desc); + if (chip && chip->name) + p = chip->name; + else + p = none; + seq_printf(m, "%-15s ", p); + + data = irq_desc_get_chip_data(desc); + seq_printf(m, "0x%16p ", data); + + if (desc->irq_data.domain->of_node) + p = desc->irq_data.domain->of_node->full_name; + else + p = none; + seq_printf(m, "%s\n", p); + } + + raw_spin_unlock_irqrestore(&desc->lock, flags); + } + + return 0; +} + +static int virq_debug_open(struct inode *inode, struct file *file) +{ + return single_open(file, virq_debug_show, inode->i_private); +} + +static const struct file_operations virq_debug_fops = { + .open = virq_debug_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init irq_debugfs_init(void) +{ + if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root, + NULL, &virq_debug_fops) == NULL) + return -ENOMEM; + + return 0; +} +__initcall(irq_debugfs_init); +#endif /* CONFIG_VIRQ_DEBUG */ + +#else /* CONFIG_PPC */ + /** * irq_domain_add() - Register an irq_domain * @domain: ptr to initialized irq_domain structure @@ -185,3 +783,5 @@ struct irq_domain_ops irq_domain_simple_ops = { #endif /* CONFIG_OF_IRQ */ }; EXPORT_SYMBOL_GPL(irq_domain_simple_ops); + +#endif /* !CONFIG_PPC */ |