i2c: imx: Add arbitration lost check

[linux-2.6/btrfs-unstable.git] / kernel / irq / irqdomain.c

#define pr_fmt(fmt)  "irq: " fmt

#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/of_irq.h>
#include <linux/topology.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);

static DEFINE_MUTEX(revmap_trees_mutex);
static struct irq_domain *irq_default_domain;

/**
 * __irq_domain_add() - Allocate a new irq_domain data structure
 * @of_node: optional device-tree node of the interrupt controller
 * @size: Size of linear map; 0 for radix mapping only
 * @hwirq_max: Maximum number of interrupts supported by controller
 * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
 *              direct mapping
 * @ops: map/unmap domain callbacks
 * @host_data: Controller private data pointer
 *
 * Allocates and initialize and irq_domain structure.
 * Returns pointer to IRQ domain, or NULL on failure.
 */
struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
                                    irq_hw_number_t hwirq_max, int direct_max,
                                    const struct irq_domain_ops *ops,
                                    void *host_data)
{
        struct irq_domain *domain;

        domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
                              GFP_KERNEL, of_node_to_nid(of_node));
        if (WARN_ON(!domain))
                return NULL;

        /* Fill structure */
        INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
        domain->ops = ops;
        domain->host_data = host_data;
        domain->of_node = of_node_get(of_node);
        domain->hwirq_max = hwirq_max;
        domain->revmap_size = size;
        domain->revmap_direct_max_irq = direct_max;

        mutex_lock(&irq_domain_mutex);
        list_add(&domain->link, &irq_domain_list);
        mutex_unlock(&irq_domain_mutex);

        pr_debug("Added domain %s\n", domain->name);
        return domain;
}
EXPORT_SYMBOL_GPL(__irq_domain_add);

/**
 * irq_domain_remove() - Remove an irq domain.
 * @domain: domain to remove
 *
 * This routine is used to remove an irq domain. The caller must ensure
 * that all mappings within the domain have been disposed of prior to
 * use, depending on the revmap type.
 */
void irq_domain_remove(struct irq_domain *domain)
{
        mutex_lock(&irq_domain_mutex);

        /*
         * radix_tree_delete() takes care of destroying the root
         * node when all entries are removed. Shout if there are
         * any mappings left.
         */
        WARN_ON(domain->revmap_tree.height);

        list_del(&domain->link);

        /*
         * If the going away domain is the default one, reset it.
         */
        if (unlikely(irq_default_domain == domain))
                irq_set_default_host(NULL);

        mutex_unlock(&irq_domain_mutex);

        pr_debug("Removed domain %s\n", domain->name);

        of_node_put(domain->of_node);
        kfree(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_remove);

/**
 * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
 * @of_node: pointer to interrupt controller's device tree node.
 * @size: total number of irqs in mapping
 * @first_irq: first number of irq block assigned to the domain,
 *      pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
 *      pre-map all of the irqs in the domain to virqs starting at first_irq.
 * @ops: map/unmap domain callbacks
 * @host_data: Controller private data pointer
 *
 * Allocates an irq_domain, and optionally if first_irq is positive then also
 * allocate irq_descs and map all of the hwirqs to virqs starting at first_irq.
 *
 * This is intended to implement the expected behaviour for most
 * interrupt controllers. If device tree is used, then first_irq will be 0 and
 * irqs get mapped dynamically on the fly. However, if the controller requires
 * static virq assignments (non-DT boot) then it will set that up correctly.
 */
struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
                                         unsigned int size,
                                         unsigned int first_irq,
                                         const struct irq_domain_ops *ops,
                                         void *host_data)
{
        struct irq_domain *domain;

        domain = __irq_domain_add(of_node, size, size, 0, ops, host_data);
        if (!domain)
                return NULL;

        if (first_irq > 0) {
                if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
                        /* attempt to allocated irq_descs */
                        int rc = irq_alloc_descs(first_irq, first_irq, size,
                                                 of_node_to_nid(of_node));
                        if (rc < 0)
                                pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
                                        first_irq);
                }
                irq_domain_associate_many(domain, first_irq, 0, size);
        }

        return domain;
}
EXPORT_SYMBOL_GPL(irq_domain_add_simple);

/**
 * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
 * @of_node: pointer to interrupt controller's device tree node.
 * @size: total number of irqs in legacy mapping
 * @first_irq: first number of irq block assigned to the domain
 * @first_hwirq: first hwirq number to use for the translation. Should normally
 *               be '0', but a positive integer can be used if the effective
 *               hwirqs numbering does not begin at zero.
 * @ops: map/unmap domain callbacks
 * @host_data: Controller private data pointer
 *
 * Note: the map() callback will be called before this function returns
 * for all legacy interrupts except 0 (which is always the invalid irq for
 * a legacy controller).
 */
struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
                                         unsigned int size,
                                         unsigned int first_irq,
                                         irq_hw_number_t first_hwirq,
                                         const struct irq_domain_ops *ops,
                                         void *host_data)
{
        struct irq_domain *domain;

        domain = __irq_domain_add(of_node, first_hwirq + size,
                                  first_hwirq + size, 0, ops, host_data);
        if (!domain)
                return NULL;

        irq_domain_associate_many(domain, first_irq, first_hwirq, size);

        return domain;
}
EXPORT_SYMBOL_GPL(irq_domain_add_legacy);

/**
 * 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;
        int rc;

        /* 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)
                        rc = h->ops->match(h, node);
                else
                        rc = (h->of_node != NULL) && (h->of_node == node);

                if (rc) {
                        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
 * @domain: default domain 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 *domain)
{
        pr_debug("Default domain set to @0x%p\n", domain);

        irq_default_domain = domain;
}
EXPORT_SYMBOL_GPL(irq_set_default_host);

void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
{
        struct irq_data *irq_data = irq_get_irq_data(irq);
        irq_hw_number_t hwirq;

        if (WARN(!irq_data || irq_data->domain != domain,
                 "virq%i doesn't exist; cannot disassociate\n", irq))
                return;

        hwirq = irq_data->hwirq;
        irq_set_status_flags(irq, IRQ_NOREQUEST);

        /* remove chip and handler */
        irq_set_chip_and_handler(irq, NULL, NULL);

        /* Make sure it's completed */
        synchronize_irq(irq);

        /* Tell the PIC about it */
        if (domain->ops->unmap)
                domain->ops->unmap(domain, irq);
        smp_mb();

        irq_data->domain = NULL;
        irq_data->hwirq = 0;

        /* Clear reverse map for this hwirq */
        if (hwirq < domain->revmap_size) {
                domain->linear_revmap[hwirq] = 0;
        } else {
                mutex_lock(&revmap_trees_mutex);
                radix_tree_delete(&domain->revmap_tree, hwirq);
                mutex_unlock(&revmap_trees_mutex);
        }
}

int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
                         irq_hw_number_t hwirq)
{
        struct irq_data *irq_data = irq_get_irq_data(virq);
        int ret;

        if (WARN(hwirq >= domain->hwirq_max,
                 "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name))
                return -EINVAL;
        if (WARN(!irq_data, "error: virq%i is not allocated", virq))
                return -EINVAL;
        if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
                return -EINVAL;

        mutex_lock(&irq_domain_mutex);
        irq_data->hwirq = hwirq;
        irq_data->domain = domain;
        if (domain->ops->map) {
                ret = domain->ops->map(domain, virq, hwirq);
                if (ret != 0) {
                        /*
                         * If map() returns -EPERM, this interrupt is protected
                         * by the firmware or some other service and shall not
                         * be mapped. Don't bother telling the user about it.
                         */
                        if (ret != -EPERM) {
                                pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
                                       domain->name, hwirq, virq, ret);
                        }
                        irq_data->domain = NULL;
                        irq_data->hwirq = 0;
                        mutex_unlock(&irq_domain_mutex);
                        return ret;
                }

                /* If not already assigned, give the domain the chip's name */
                if (!domain->name && irq_data->chip)
                        domain->name = irq_data->chip->name;
        }

        if (hwirq < domain->revmap_size) {
                domain->linear_revmap[hwirq] = virq;
        } else {
                mutex_lock(&revmap_trees_mutex);
                radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
                mutex_unlock(&revmap_trees_mutex);
        }
        mutex_unlock(&irq_domain_mutex);

        irq_clear_status_flags(virq, IRQ_NOREQUEST);

        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_associate);

void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
                               irq_hw_number_t hwirq_base, int count)
{
        int i;

        pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
                of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);

        for (i = 0; i < count; i++) {
                irq_domain_associate(domain, irq_base + i, hwirq_base + i);
        }
}
EXPORT_SYMBOL_GPL(irq_domain_associate_many);

/**
 * irq_create_direct_mapping() - Allocate an irq for direct mapping
 * @domain: domain to allocate the irq for or NULL for default domain
 *
 * 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. It still uses the linear
 * or radix tree to store the mapping, but the irq controller can optimize
 * the revmap path by using the hwirq directly.
 */
unsigned int irq_create_direct_mapping(struct irq_domain *domain)
{
        unsigned int virq;

        if (domain == NULL)
                domain = irq_default_domain;

        virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
        if (!virq) {
                pr_debug("create_direct virq allocation failed\n");
                return 0;
        }
        if (virq >= domain->revmap_direct_max_irq) {
                pr_err("ERROR: no free irqs available below %i maximum\n",
                        domain->revmap_direct_max_irq);
                irq_free_desc(virq);
                return 0;
        }
        pr_debug("create_direct obtained virq %d\n", virq);

        if (irq_domain_associate(domain, virq, virq)) {
                irq_free_desc(virq);
                return 0;
        }

        return virq;
}
EXPORT_SYMBOL_GPL(irq_create_direct_mapping);

/**
 * irq_create_mapping() - Map a hardware interrupt into linux irq space
 * @domain: domain owning this hardware interrupt or NULL for default domain
 * @hwirq: hardware irq number in that domain 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 *domain,
                                irq_hw_number_t hwirq)
{
        unsigned int hint;
        int virq;

        pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);

        /* Look for default domain if nececssary */
        if (domain == NULL)
                domain = irq_default_domain;
        if (domain == NULL) {
                WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
                return 0;
        }
        pr_debug("-> using domain @%p\n", domain);

        /* Check if mapping already exists */
        virq = irq_find_mapping(domain, hwirq);
        if (virq) {
                pr_debug("-> existing mapping on virq %d\n", virq);
                return virq;
        }

        /* Allocate a virtual interrupt number */
        hint = hwirq % nr_irqs;
        if (hint == 0)
                hint++;
        virq = irq_alloc_desc_from(hint, of_node_to_nid(domain->of_node));
        if (virq <= 0)
                virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
        if (virq <= 0) {
                pr_debug("-> virq allocation failed\n");
                return 0;
        }

        if (irq_domain_associate(domain, virq, hwirq)) {
                irq_free_desc(virq);
                return 0;
        }

        pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
                hwirq, of_node_full_name(domain->of_node), virq);

        return virq;
}
EXPORT_SYMBOL_GPL(irq_create_mapping);

/**
 * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
 * @domain: domain owning the interrupt range
 * @irq_base: beginning of linux IRQ range
 * @hwirq_base: beginning of hardware IRQ range
 * @count: Number of interrupts to map
 *
 * This routine is used for allocating and mapping a range of hardware
 * irqs to linux irqs where the linux irq numbers are at pre-defined
 * locations. For use by controllers that already have static mappings
 * to insert in to the domain.
 *
 * Non-linear users can use irq_create_identity_mapping() for IRQ-at-a-time
 * domain insertion.
 *
 * 0 is returned upon success, while any failure to establish a static
 * mapping is treated as an error.
 */
int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
                               irq_hw_number_t hwirq_base, int count)
{
        int ret;

        ret = irq_alloc_descs(irq_base, irq_base, count,
                              of_node_to_nid(domain->of_node));
        if (unlikely(ret < 0))
                return ret;

        irq_domain_associate_many(domain, irq_base, hwirq_base, count);
        return 0;
}
EXPORT_SYMBOL_GPL(irq_create_strict_mappings);

unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
{
        struct irq_domain *domain;
        irq_hw_number_t hwirq;
        unsigned int type = IRQ_TYPE_NONE;
        unsigned int virq;

        domain = irq_data->np ? irq_find_host(irq_data->np) : irq_default_domain;
        if (!domain) {
                pr_warn("no irq domain found for %s !\n",
                        of_node_full_name(irq_data->np));
                return 0;
        }

        /* If domain has no translation, then we assume interrupt line */
        if (domain->ops->xlate == NULL)
                hwirq = irq_data->args[0];
        else {
                if (domain->ops->xlate(domain, irq_data->np, irq_data->args,
                                        irq_data->args_count, &hwirq, &type))
                        return 0;
        }

        /* Create mapping */
        virq = irq_create_mapping(domain, hwirq);
        if (!virq)
                return virq;

        /* Set type if specified and different than the current one */
        if (type != IRQ_TYPE_NONE &&
            type != irq_get_trigger_type(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 *domain;

        if (!virq || !irq_data)
                return;

        domain = irq_data->domain;
        if (WARN_ON(domain == NULL))
                return;

        irq_domain_disassociate(domain, virq);
        irq_free_desc(virq);
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);

/**
 * irq_find_mapping() - Find a linux irq from an hw irq number.
 * @domain: domain owning this hardware interrupt
 * @hwirq: hardware irq number in that domain space
 */
unsigned int irq_find_mapping(struct irq_domain *domain,
                              irq_hw_number_t hwirq)
{
        struct irq_data *data;

        /* Look for default domain if nececssary */
        if (domain == NULL)
                domain = irq_default_domain;
        if (domain == NULL)
                return 0;

        if (hwirq < domain->revmap_direct_max_irq) {
                data = irq_get_irq_data(hwirq);
                if (data && (data->domain == domain) && (data->hwirq == hwirq))
                        return hwirq;
        }

        /* Check if the hwirq is in the linear revmap. */
        if (hwirq < domain->revmap_size)
                return domain->linear_revmap[hwirq];

        rcu_read_lock();
        data = radix_tree_lookup(&domain->revmap_tree, hwirq);
        rcu_read_unlock();
        return data ? data->irq : 0;
}
EXPORT_SYMBOL_GPL(irq_find_mapping);

#ifdef CONFIG_IRQ_DOMAIN_DEBUG
static int virq_debug_show(struct seq_file *m, void *private)
{
        unsigned long flags;
        struct irq_desc *desc;
        struct irq_domain *domain;
        struct radix_tree_iter iter;
        void *data, **slot;
        int i;

        seq_printf(m, " %-16s  %-6s  %-10s  %-10s  %s\n",
                   "name", "mapped", "linear-max", "direct-max", "devtree-node");
        mutex_lock(&irq_domain_mutex);
        list_for_each_entry(domain, &irq_domain_list, link) {
                int count = 0;
                radix_tree_for_each_slot(slot, &domain->revmap_tree, &iter, 0)
                        count++;
                seq_printf(m, "%c%-16s  %6u  %10u  %10u  %s\n",
                           domain == irq_default_domain ? '*' : ' ', domain->name,
                           domain->revmap_size + count, domain->revmap_size,
                           domain->revmap_direct_max_irq,
                           domain->of_node ? of_node_full_name(domain->of_node) : "");
        }
        mutex_unlock(&irq_domain_mutex);

        seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %6s  %-14s  %s\n", "irq", "hwirq",
                      "chip name", (int)(2 * sizeof(void *) + 2), "chip data",
                      "active", "type", "domain");

        for (i = 1; i < nr_irqs; i++) {
                desc = irq_to_desc(i);
                if (!desc)
                        continue;

                raw_spin_lock_irqsave(&desc->lock, flags);
                domain = desc->irq_data.domain;

                if (domain) {
                        struct irq_chip *chip;
                        int hwirq = desc->irq_data.hwirq;
                        bool direct;

                        seq_printf(m, "%5d  ", i);
                        seq_printf(m, "0x%05x  ", hwirq);

                        chip = irq_desc_get_chip(desc);
                        seq_printf(m, "%-15s  ", (chip && chip->name) ? chip->name : "none");

                        data = irq_desc_get_chip_data(desc);
                        seq_printf(m, data ? "0x%p  " : "  %p  ", data);

                        seq_printf(m, "   %c    ", (desc->action && desc->action->handler) ? '*' : ' ');
                        direct = (i == hwirq) && (i < domain->revmap_direct_max_irq);
                        seq_printf(m, "%6s%-8s  ",
                                   (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX",
                                   direct ? "(DIRECT)" : "");
                        seq_printf(m, "%s\n", desc->irq_data.domain->name);
                }

                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("irq_domain_mapping", S_IRUGO, NULL,
                                 NULL, &virq_debug_fops) == NULL)
                return -ENOMEM;

        return 0;
}
__initcall(irq_debugfs_init);
#endif /* CONFIG_IRQ_DOMAIN_DEBUG */

/**
 * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
 *
 * Device Tree IRQ specifier translation function which works with one cell
 * bindings where the cell value maps directly to the hwirq number.
 */
int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
                             const u32 *intspec, unsigned int intsize,
                             unsigned long *out_hwirq, unsigned int *out_type)
{
        if (WARN_ON(intsize < 1))
                return -EINVAL;
        *out_hwirq = intspec[0];
        *out_type = IRQ_TYPE_NONE;
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_onecell);

/**
 * irq_domain_xlate_twocell() - Generic xlate for direct two cell bindings
 *
 * Device Tree IRQ specifier translation function which works with two cell
 * bindings where the cell values map directly to the hwirq number
 * and linux irq flags.
 */
int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
                        const u32 *intspec, unsigned int intsize,
                        irq_hw_number_t *out_hwirq, unsigned int *out_type)
{
        if (WARN_ON(intsize < 2))
                return -EINVAL;
        *out_hwirq = intspec[0];
        *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);

/**
 * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
 *
 * Device Tree IRQ specifier translation function which works with either one
 * or two cell bindings where the cell values map directly to the hwirq number
 * and linux irq flags.
 *
 * Note: don't use this function unless your interrupt controller explicitly
 * supports both one and two cell bindings.  For the majority of controllers
 * the _onecell() or _twocell() variants above should be used.
 */
int irq_domain_xlate_onetwocell(struct irq_domain *d,
                                struct device_node *ctrlr,
                                const u32 *intspec, unsigned int intsize,
                                unsigned long *out_hwirq, unsigned int *out_type)
{
        if (WARN_ON(intsize < 1))
                return -EINVAL;
        *out_hwirq = intspec[0];
        *out_type = (intsize > 1) ? intspec[1] : IRQ_TYPE_NONE;
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);

const struct irq_domain_ops irq_domain_simple_ops = {
        .xlate = irq_domain_xlate_onetwocell,
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);