diff options
author | Aurelien Jacquiot <a-jacquiot@ti.com> | 2011-10-04 11:06:27 -0400 |
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committer | Mark Salter <msalter@redhat.com> | 2011-10-06 19:47:54 -0400 |
commit | ec500af3059b474df35418c41c684c1cde830c81 (patch) | |
tree | fca5ee52137efe4fc9d9c07ddce4f4e4ea52ba16 /arch/c6x/kernel | |
parent | 546a39546c64ad7e73796c5508ef5487af42cae2 (diff) | |
download | blackbird-op-linux-ec500af3059b474df35418c41c684c1cde830c81.tar.gz blackbird-op-linux-ec500af3059b474df35418c41c684c1cde830c81.zip |
C6X: interrupt handling
Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/c6x/kernel')
-rw-r--r-- | arch/c6x/kernel/irq.c | 728 |
1 files changed, 728 insertions, 0 deletions
diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c new file mode 100644 index 000000000000..0929e4b2b244 --- /dev/null +++ b/arch/c6x/kernel/irq.c @@ -0,0 +1,728 @@ +/* + * Copyright (C) 2011 Texas Instruments Incorporated + * + * This borrows heavily from powerpc version, which is: + * + * Derived from arch/i386/kernel/irq.c + * Copyright (C) 1992 Linus Torvalds + * Adapted from arch/i386 by Gary Thomas + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * Updated and modified by Cort Dougan <cort@fsmlabs.com> + * Copyright (C) 1996-2001 Cort Dougan + * Adapted for Power Macintosh by Paul Mackerras + * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/radix-tree.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> + +#include <asm/megamod-pic.h> + +unsigned long irq_err_count; + +static DEFINE_RAW_SPINLOCK(core_irq_lock); + +static void mask_core_irq(struct irq_data *data) +{ + unsigned int prio = data->irq; + + BUG_ON(prio < 4 || prio >= NR_PRIORITY_IRQS); + + raw_spin_lock(&core_irq_lock); + and_creg(IER, ~(1 << prio)); + raw_spin_unlock(&core_irq_lock); +} + +static void unmask_core_irq(struct irq_data *data) +{ + unsigned int prio = data->irq; + + raw_spin_lock(&core_irq_lock); + or_creg(IER, 1 << prio); + raw_spin_unlock(&core_irq_lock); +} + +static struct irq_chip core_chip = { + .name = "core", + .irq_mask = mask_core_irq, + .irq_unmask = unmask_core_irq, +}; + +asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + BUG_ON(prio < 4 || prio >= NR_PRIORITY_IRQS); + + generic_handle_irq(prio); + + irq_exit(); + + set_irq_regs(old_regs); +} + +static struct irq_host *core_host; + +static int core_host_map(struct irq_host *h, unsigned int virq, + irq_hw_number_t hw) +{ + if (hw < 4 || hw >= NR_PRIORITY_IRQS) + return -EINVAL; + + irq_set_status_flags(virq, IRQ_LEVEL); + irq_set_chip_and_handler(virq, &core_chip, handle_level_irq); + return 0; +} + +static struct irq_host_ops core_host_ops = { + .map = core_host_map, +}; + +void __init init_IRQ(void) +{ + struct device_node *np; + + /* Mask all priority IRQs */ + and_creg(IER, ~0xfff0); + + np = of_find_compatible_node(NULL, NULL, "ti,c64x+core-pic"); + if (np != NULL) { + /* create the core host */ + core_host = irq_alloc_host(np, IRQ_HOST_MAP_PRIORITY, 0, + &core_host_ops, 0); + if (core_host) + irq_set_default_host(core_host); + of_node_put(np); + } + + printk(KERN_INFO "Core interrupt controller initialized\n"); + + /* now we're ready for other SoC controllers */ + megamod_pic_init(); + + /* Clear all general IRQ flags */ + set_creg(ICR, 0xfff0); +} + +void ack_bad_irq(int irq) +{ + printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq); + irq_err_count++; +} + +int arch_show_interrupts(struct seq_file *p, int prec) +{ + seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); + return 0; +} + +/* + * IRQ controller and virtual interrupts + */ + +/* The main irq map itself is an array of NR_IRQ entries containing the + * associate host and irq number. An entry with a host of NULL is free. + * An entry can be allocated if it's free, the allocator always then sets + * hwirq first to the host's invalid irq number and then fills ops. + */ +struct irq_map_entry { + irq_hw_number_t hwirq; + struct irq_host *host; +}; + +static LIST_HEAD(irq_hosts); +static DEFINE_RAW_SPINLOCK(irq_big_lock); +static DEFINE_MUTEX(revmap_trees_mutex); +static struct irq_map_entry irq_map[NR_IRQS]; +static unsigned int irq_virq_count = NR_IRQS; +static struct irq_host *irq_default_host; + +irq_hw_number_t irqd_to_hwirq(struct irq_data *d) +{ + return irq_map[d->irq].hwirq; +} +EXPORT_SYMBOL_GPL(irqd_to_hwirq); + +irq_hw_number_t virq_to_hw(unsigned int virq) +{ + return irq_map[virq].hwirq; +} +EXPORT_SYMBOL_GPL(virq_to_hw); + +bool virq_is_host(unsigned int virq, struct irq_host *host) +{ + return irq_map[virq].host == host; +} +EXPORT_SYMBOL_GPL(virq_is_host); + +static int default_irq_host_match(struct irq_host *h, struct device_node *np) +{ + return h->of_node != NULL && h->of_node == np; +} + +struct irq_host *irq_alloc_host(struct device_node *of_node, + unsigned int revmap_type, + unsigned int revmap_arg, + struct irq_host_ops *ops, + irq_hw_number_t inval_irq) +{ + struct irq_host *host; + unsigned int size = sizeof(struct irq_host); + unsigned int i; + unsigned int *rmap; + unsigned long flags; + + /* Allocate structure and revmap table if using linear mapping */ + if (revmap_type == IRQ_HOST_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; + + raw_spin_lock_irqsave(&irq_big_lock, flags); + + /* Check for the priority controller. */ + if (revmap_type == IRQ_HOST_MAP_PRIORITY) { + if (irq_map[0].host != NULL) { + raw_spin_unlock_irqrestore(&irq_big_lock, flags); + of_node_put(host->of_node); + kfree(host); + return NULL; + } + irq_map[0].host = host; + } + + list_add(&host->link, &irq_hosts); + raw_spin_unlock_irqrestore(&irq_big_lock, flags); + + /* Additional setups per revmap type */ + switch (revmap_type) { + case IRQ_HOST_MAP_PRIORITY: + /* 0 is always the invalid number for priority */ + host->inval_irq = 0; + /* setup us as the host for all priority interrupts */ + for (i = 1; i < NR_PRIORITY_IRQS; i++) { + irq_map[i].hwirq = i; + smp_wmb(); + irq_map[i].host = host; + smp_wmb(); + + ops->map(host, i, i); + } + break; + case IRQ_HOST_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; + smp_wmb(); + host->revmap_data.linear.revmap = rmap; + break; + case IRQ_HOST_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; +} + +struct irq_host *irq_find_host(struct device_node *node) +{ + struct irq_host *h, *found = NULL; + unsigned long flags; + + /* 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... + */ + raw_spin_lock_irqsave(&irq_big_lock, flags); + list_for_each_entry(h, &irq_hosts, link) + if (h->ops->match(h, node)) { + found = h; + break; + } + raw_spin_unlock_irqrestore(&irq_big_lock, flags); + return found; +} +EXPORT_SYMBOL_GPL(irq_find_host); + +void irq_set_default_host(struct irq_host *host) +{ + pr_debug("irq: Default host set to @0x%p\n", host); + + irq_default_host = host; +} + +void irq_set_virq_count(unsigned int count) +{ + pr_debug("irq: Trying to set virq count to %d\n", count); + + BUG_ON(count < NR_PRIORITY_IRQS); + if (count < NR_IRQS) + irq_virq_count = count; +} + +static int irq_setup_virq(struct irq_host *host, unsigned int virq, + irq_hw_number_t hwirq) +{ + int res; + + res = irq_alloc_desc_at(virq, 0); + if (res != virq) { + pr_debug("irq: -> allocating desc failed\n"); + goto error; + } + + /* map it */ + smp_wmb(); + irq_map[virq].hwirq = hwirq; + smp_mb(); + + if (host->ops->map(host, virq, hwirq)) { + pr_debug("irq: -> mapping failed, freeing\n"); + goto errdesc; + } + + irq_clear_status_flags(virq, IRQ_NOREQUEST); + + return 0; + +errdesc: + irq_free_descs(virq, 1); +error: + irq_free_virt(virq, 1); + return -1; +} + +unsigned int irq_create_direct_mapping(struct irq_host *host) +{ + unsigned int virq; + + if (host == NULL) + host = irq_default_host; + + BUG_ON(host == NULL); + WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP); + + virq = irq_alloc_virt(host, 1, 0); + if (virq == NO_IRQ) { + pr_debug("irq: create_direct virq allocation failed\n"); + return NO_IRQ; + } + + pr_debug("irq: create_direct obtained virq %d\n", virq); + + if (irq_setup_virq(host, virq, virq)) + return NO_IRQ; + + return virq; +} + +unsigned int irq_create_mapping(struct irq_host *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; + } + + /* Allocate a virtual interrupt number */ + hint = hwirq % irq_virq_count; + virq = irq_alloc_virt(host, 1, hint); + if (virq == NO_IRQ) { + pr_debug("irq: -> virq allocation failed\n"); + return NO_IRQ; + } + + if (irq_setup_virq(host, virq, hwirq)) + 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_host *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); + +void irq_dispose_mapping(unsigned int virq) +{ + struct irq_host *host; + irq_hw_number_t hwirq; + + if (virq == NO_IRQ) + return; + + /* Never unmap priority interrupts */ + if (virq < NR_PRIORITY_IRQS) + return; + + host = irq_map[virq].host; + if (WARN_ON(host == NULL)) + 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_map[virq].hwirq; + switch (host->revmap_type) { + case IRQ_HOST_MAP_LINEAR: + if (hwirq < host->revmap_data.linear.size) + host->revmap_data.linear.revmap[hwirq] = NO_IRQ; + break; + case IRQ_HOST_MAP_TREE: + mutex_lock(&revmap_trees_mutex); + radix_tree_delete(&host->revmap_data.tree, hwirq); + mutex_unlock(&revmap_trees_mutex); + break; + } + + /* Destroy map */ + smp_mb(); + irq_map[virq].hwirq = host->inval_irq; + + irq_free_descs(virq, 1); + /* Free it */ + irq_free_virt(virq, 1); +} +EXPORT_SYMBOL_GPL(irq_dispose_mapping); + +unsigned int irq_find_mapping(struct irq_host *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; + + /* Slow path does a linear search of the map */ + i = hint; + do { + if (irq_map[i].host == host && + irq_map[i].hwirq == hwirq) + return i; + i++; + if (i >= irq_virq_count) + i = 4; + } while (i != hint); + return NO_IRQ; +} +EXPORT_SYMBOL_GPL(irq_find_mapping); + +unsigned int irq_radix_revmap_lookup(struct irq_host *host, + irq_hw_number_t hwirq) +{ + struct irq_map_entry *ptr; + unsigned int virq; + + if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE)) + return irq_find_mapping(host, hwirq); + + /* + * The ptr returned references the static global irq_map. + * but freeing an irq can delete nodes along the path to + * do the lookup via call_rcu. + */ + rcu_read_lock(); + ptr = 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. + */ + if (ptr) + virq = ptr - irq_map; + else + virq = irq_find_mapping(host, hwirq); + + return virq; +} + +void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq, + irq_hw_number_t hwirq) +{ + if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE)) + return; + + if (virq != NO_IRQ) { + mutex_lock(&revmap_trees_mutex); + radix_tree_insert(&host->revmap_data.tree, hwirq, + &irq_map[virq]); + mutex_unlock(&revmap_trees_mutex); + } +} + +unsigned int irq_linear_revmap(struct irq_host *host, + irq_hw_number_t hwirq) +{ + unsigned int *revmap; + + if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_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]; +} + +unsigned int irq_alloc_virt(struct irq_host *host, + unsigned int count, + unsigned int hint) +{ + unsigned long flags; + unsigned int i, j, found = NO_IRQ; + + if (count == 0 || count > (irq_virq_count - NR_PRIORITY_IRQS)) + return NO_IRQ; + + raw_spin_lock_irqsave(&irq_big_lock, flags); + + /* Use hint for 1 interrupt if any */ + if (count == 1 && hint >= NR_PRIORITY_IRQS && + hint < irq_virq_count && irq_map[hint].host == NULL) { + found = hint; + goto hint_found; + } + + /* Look for count consecutive numbers in the allocatable + * (non-legacy) space + */ + for (i = NR_PRIORITY_IRQS, j = 0; i < irq_virq_count; i++) { + if (irq_map[i].host != NULL) + j = 0; + else + j++; + + if (j == count) { + found = i - count + 1; + break; + } + } + if (found == NO_IRQ) { + raw_spin_unlock_irqrestore(&irq_big_lock, flags); + return NO_IRQ; + } + hint_found: + for (i = found; i < (found + count); i++) { + irq_map[i].hwirq = host->inval_irq; + smp_wmb(); + irq_map[i].host = host; + } + raw_spin_unlock_irqrestore(&irq_big_lock, flags); + return found; +} + +void irq_free_virt(unsigned int virq, unsigned int count) +{ + unsigned long flags; + unsigned int i; + + WARN_ON(virq < NR_PRIORITY_IRQS); + WARN_ON(count == 0 || (virq + count) > irq_virq_count); + + if (virq < NR_PRIORITY_IRQS) { + if (virq + count < NR_PRIORITY_IRQS) + return; + count -= NR_PRIORITY_IRQS - virq; + virq = NR_PRIORITY_IRQS; + } + + if (count > irq_virq_count || virq > irq_virq_count - count) { + if (virq > irq_virq_count) + return; + count = irq_virq_count - virq; + } + + raw_spin_lock_irqsave(&irq_big_lock, flags); + for (i = virq; i < (virq + count); i++) { + struct irq_host *host; + + host = irq_map[i].host; + irq_map[i].hwirq = host->inval_irq; + smp_wmb(); + irq_map[i].host = NULL; + } + raw_spin_unlock_irqrestore(&irq_big_lock, flags); +} + +#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 ", irq_map[i].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 (irq_map[i].host && irq_map[i].host->of_node) + p = irq_map[i].host->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; +} +device_initcall(irq_debugfs_init); +#endif /* CONFIG_VIRQ_DEBUG */ |