genirq: Make sparse_lock a mutex
[pandora-kernel.git] / kernel / irq / irqdesc.c
index 78ff426..0e302f9 100644 (file)
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 #include <linux/radix-tree.h>
+#include <linux/bitmap.h>
 
 #include "internals.h"
 
 /*
  * lockdep: we want to handle all irq_desc locks as a single lock-class:
  */
-struct lock_class_key irq_desc_lock_class;
+static struct lock_class_key irq_desc_lock_class;
 
 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 static void __init init_irq_default_affinity(void)
@@ -33,66 +34,70 @@ static void __init init_irq_default_affinity(void)
 }
 #endif
 
-int nr_irqs = NR_IRQS;
-EXPORT_SYMBOL_GPL(nr_irqs);
-
-#ifdef CONFIG_SPARSE_IRQ
+#ifdef CONFIG_SMP
+static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
+{
+       if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
+               return -ENOMEM;
 
-static struct irq_desc irq_desc_init = {
-       .status         = IRQ_DISABLED,
-       .handle_irq     = handle_bad_irq,
-       .depth          = 1,
-       .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
-};
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+       if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
+               free_cpumask_var(desc->irq_data.affinity);
+               return -ENOMEM;
+       }
+#endif
+       return 0;
+}
 
-void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
+static void desc_smp_init(struct irq_desc *desc, int node)
 {
-       void *ptr;
-
-       ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs),
-                          GFP_ATOMIC, node);
-
-       /*
-        * don't overwite if can not get new one
-        * init_copy_kstat_irqs() could still use old one
-        */
-       if (ptr) {
-               printk(KERN_DEBUG "  alloc kstat_irqs on node %d\n", node);
-               desc->kstat_irqs = ptr;
-       }
+       desc->irq_data.node = node;
+       cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+       cpumask_clear(desc->pending_mask);
+#endif
 }
 
-static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
+static inline int desc_node(struct irq_desc *desc)
 {
-       memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
+       return desc->irq_data.node;
+}
 
-       raw_spin_lock_init(&desc->lock);
-       desc->irq_data.irq = irq;
-#ifdef CONFIG_SMP
-       desc->irq_data.node = node;
+#else
+static inline int
+alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
+static inline void desc_smp_init(struct irq_desc *desc, int node) { }
+static inline int desc_node(struct irq_desc *desc) { return 0; }
 #endif
-       lockdep_set_class(&desc->lock, &irq_desc_lock_class);
-       init_kstat_irqs(desc, node, nr_cpu_ids);
-       if (!desc->kstat_irqs) {
-               printk(KERN_ERR "can not alloc kstat_irqs\n");
-               BUG_ON(1);
-       }
-       if (!alloc_desc_masks(desc, node, false)) {
-               printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
-               BUG_ON(1);
-       }
-       init_desc_masks(desc);
-       arch_init_chip_data(desc, node);
+
+static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
+{
+       desc->irq_data.irq = irq;
+       desc->irq_data.chip = &no_irq_chip;
+       desc->irq_data.chip_data = NULL;
+       desc->irq_data.handler_data = NULL;
+       desc->irq_data.msi_desc = NULL;
+       desc->status = IRQ_DEFAULT_INIT_FLAGS;
+       desc->handle_irq = handle_bad_irq;
+       desc->depth = 1;
+       desc->irq_count = 0;
+       desc->irqs_unhandled = 0;
+       desc->name = NULL;
+       memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
+       desc_smp_init(desc, node);
 }
 
-/*
- * Protect the sparse_irqs:
- */
-DEFINE_RAW_SPINLOCK(sparse_irq_lock);
+int nr_irqs = NR_IRQS;
+EXPORT_SYMBOL_GPL(nr_irqs);
+
+static DEFINE_MUTEX(sparse_irq_lock);
+static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
+
+#ifdef CONFIG_SPARSE_IRQ
 
 static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
 
-static void set_irq_desc(unsigned int irq, struct irq_desc *desc)
+static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 {
        radix_tree_insert(&irq_desc_tree, irq, desc);
 }
@@ -102,109 +107,128 @@ struct irq_desc *irq_to_desc(unsigned int irq)
        return radix_tree_lookup(&irq_desc_tree, irq);
 }
 
-void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
+static void delete_irq_desc(unsigned int irq)
 {
-       void **ptr;
-
-       ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
-       if (ptr)
-               radix_tree_replace_slot(ptr, desc);
+       radix_tree_delete(&irq_desc_tree, irq);
 }
 
-static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
-       [0 ... NR_IRQS_LEGACY-1] = {
-               .status         = IRQ_DISABLED,
-               .handle_irq     = handle_bad_irq,
-               .depth          = 1,
-               .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
-       }
-};
-
-static unsigned int *kstat_irqs_legacy;
+#ifdef CONFIG_SMP
+static void free_masks(struct irq_desc *desc)
+{
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+       free_cpumask_var(desc->pending_mask);
+#endif
+       free_cpumask_var(desc->affinity);
+}
+#else
+static inline void free_masks(struct irq_desc *desc) { }
+#endif
 
-int __init early_irq_init(void)
+static struct irq_desc *alloc_desc(int irq, int node)
 {
+       /* Temporary hack until we can switch to GFP_KERNEL */
+       gfp_t gfp = gfp_allowed_mask == GFP_BOOT_MASK ? GFP_NOWAIT : GFP_ATOMIC;
        struct irq_desc *desc;
-       int legacy_count;
-       int node;
-       int i;
 
-       init_irq_default_affinity();
+       desc = kzalloc_node(sizeof(*desc), gfp, node);
+       if (!desc)
+               return NULL;
+       /* allocate based on nr_cpu_ids */
+       desc->kstat_irqs = kzalloc_node(nr_cpu_ids * sizeof(*desc->kstat_irqs),
+                                        gfp, node);
+       if (!desc->kstat_irqs)
+               goto err_desc;
 
-        /* initialize nr_irqs based on nr_cpu_ids */
-       arch_probe_nr_irqs();
-       printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d\n", NR_IRQS, nr_irqs);
+       if (alloc_masks(desc, gfp, node))
+               goto err_kstat;
 
-       desc = irq_desc_legacy;
-       legacy_count = ARRAY_SIZE(irq_desc_legacy);
-       node = first_online_node;
+       raw_spin_lock_init(&desc->lock);
+       lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 
-       /* allocate based on nr_cpu_ids */
-       kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *
-                                         sizeof(int), GFP_NOWAIT, node);
+       desc_set_defaults(irq, desc, node);
 
-       irq_desc_init.irq_data.chip = &no_irq_chip;
+       return desc;
 
-       for (i = 0; i < legacy_count; i++) {
-               desc[i].irq_data.irq = i;
-               desc[i].irq_data.chip = &no_irq_chip;
-#ifdef CONFIG_SMP
-               desc[i].irq_data.node = node;
-#endif
-               desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
-               lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
-               alloc_desc_masks(&desc[i], node, true);
-               init_desc_masks(&desc[i]);
-               set_irq_desc(i, &desc[i]);
-       }
+err_kstat:
+       kfree(desc->kstat_irqs);
+err_desc:
+       kfree(desc);
+       return NULL;
+}
 
-       return arch_early_irq_init();
+static void free_desc(unsigned int irq)
+{
+       struct irq_desc *desc = irq_to_desc(irq);
+
+       unregister_irq_proc(irq, desc);
+
+       mutex_lock(&sparse_irq_lock);
+       delete_irq_desc(irq);
+       mutex_unlock(&sparse_irq_lock);
+
+       free_masks(desc);
+       kfree(desc->kstat_irqs);
+       kfree(desc);
 }
 
-struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
+static int alloc_descs(unsigned int start, unsigned int cnt, int node)
 {
        struct irq_desc *desc;
-       unsigned long flags;
+       int i;
 
-       if (irq >= nr_irqs) {
-               WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
-                       irq, nr_irqs);
-               return NULL;
+       for (i = 0; i < cnt; i++) {
+               desc = alloc_desc(start + i, node);
+               if (!desc)
+                       goto err;
+               mutex_lock(&sparse_irq_lock);
+               irq_insert_desc(start + i, desc);
+               mutex_unlock(&sparse_irq_lock);
        }
+       return start;
 
-       desc = irq_to_desc(irq);
-       if (desc)
-               return desc;
+err:
+       for (i--; i >= 0; i--)
+               free_desc(start + i);
 
-       raw_spin_lock_irqsave(&sparse_irq_lock, flags);
+       mutex_lock(&sparse_irq_lock);
+       bitmap_clear(allocated_irqs, start, cnt);
+       mutex_unlock(&sparse_irq_lock);
+       return -ENOMEM;
+}
 
-       /* We have to check it to avoid races with another CPU */
-       desc = irq_to_desc(irq);
-       if (desc)
-               goto out_unlock;
+struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
+{
+       int res = irq_alloc_descs(irq, irq, 1, node);
 
-       desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+       if (res == -EEXIST || res == irq)
+               return irq_to_desc(irq);
+       return NULL;
+}
 
-       printk(KERN_DEBUG "  alloc irq_desc for %d on node %d\n", irq, node);
-       if (!desc) {
-               printk(KERN_ERR "can not alloc irq_desc\n");
-               BUG_ON(1);
-       }
-       init_one_irq_desc(irq, desc, node);
+int __init early_irq_init(void)
+{
+       int i, initcnt, node = first_online_node;
+       struct irq_desc *desc;
 
-       set_irq_desc(irq, desc);
+       init_irq_default_affinity();
 
-out_unlock:
-       raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
+       /* Let arch update nr_irqs and return the nr of preallocated irqs */
+       initcnt = arch_probe_nr_irqs();
+       printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 
-       return desc;
+       for (i = 0; i < initcnt; i++) {
+               desc = alloc_desc(i, node);
+               set_bit(i, allocated_irqs);
+               irq_insert_desc(i, desc);
+       }
+       return arch_early_irq_init();
 }
 
 #else /* !CONFIG_SPARSE_IRQ */
 
 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
        [0 ... NR_IRQS-1] = {
-               .status         = IRQ_DISABLED,
+               .status         = IRQ_DEFAULT_INIT_FLAGS,
                .handle_irq     = handle_bad_irq,
                .depth          = 1,
                .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
@@ -214,9 +238,8 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS];
 int __init early_irq_init(void)
 {
+       int count, i, node = first_online_node;
        struct irq_desc *desc;
-       int count;
-       int i;
 
        init_irq_default_affinity();
 
@@ -228,9 +251,9 @@ int __init early_irq_init(void)
        for (i = 0; i < count; i++) {
                desc[i].irq_data.irq = i;
                desc[i].irq_data.chip = &no_irq_chip;
-               alloc_desc_masks(&desc[i], 0, true);
-               init_desc_masks(&desc[i]);
                desc[i].kstat_irqs = kstat_irqs_all[i];
+               alloc_masks(desc + i, GFP_KERNEL, node);
+               desc_smp_init(desc + i, node);
                lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
        }
        return arch_early_irq_init();
@@ -245,11 +268,125 @@ struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
 {
        return irq_to_desc(irq);
 }
+
+static void free_desc(unsigned int irq)
+{
+       dynamic_irq_cleanup(irq);
+}
+
+static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
+{
+       return start;
+}
 #endif /* !CONFIG_SPARSE_IRQ */
 
-void clear_kstat_irqs(struct irq_desc *desc)
+/* Dynamic interrupt handling */
+
+/**
+ * irq_free_descs - free irq descriptors
+ * @from:      Start of descriptor range
+ * @cnt:       Number of consecutive irqs to free
+ */
+void irq_free_descs(unsigned int from, unsigned int cnt)
 {
-       memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
+       int i;
+
+       if (from >= nr_irqs || (from + cnt) > nr_irqs)
+               return;
+
+       for (i = 0; i < cnt; i++)
+               free_desc(from + i);
+
+       mutex_lock(&sparse_irq_lock);
+       bitmap_clear(allocated_irqs, from, cnt);
+       mutex_unlock(&sparse_irq_lock);
+}
+
+/**
+ * irq_alloc_descs - allocate and initialize a range of irq descriptors
+ * @irq:       Allocate for specific irq number if irq >= 0
+ * @from:      Start the search from this irq number
+ * @cnt:       Number of consecutive irqs to allocate.
+ * @node:      Preferred node on which the irq descriptor should be allocated
+ *
+ * Returns the first irq number or error code
+ */
+int __ref
+irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
+{
+       int start, ret;
+
+       if (!cnt)
+               return -EINVAL;
+
+       mutex_lock(&sparse_irq_lock);
+
+       start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
+       ret = -EEXIST;
+       if (irq >=0 && start != irq)
+               goto err;
+
+       ret = -ENOMEM;
+       if (start >= nr_irqs)
+               goto err;
+
+       bitmap_set(allocated_irqs, start, cnt);
+       mutex_unlock(&sparse_irq_lock);
+       return alloc_descs(start, cnt, node);
+
+err:
+       mutex_unlock(&sparse_irq_lock);
+       return ret;
+}
+
+/**
+ * irq_reserve_irqs - mark irqs allocated
+ * @from:      mark from irq number
+ * @cnt:       number of irqs to mark
+ *
+ * Returns 0 on success or an appropriate error code
+ */
+int irq_reserve_irqs(unsigned int from, unsigned int cnt)
+{
+       unsigned int start;
+       int ret = 0;
+
+       if (!cnt || (from + cnt) > nr_irqs)
+               return -EINVAL;
+
+       mutex_lock(&sparse_irq_lock);
+       start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
+       if (start == from)
+               bitmap_set(allocated_irqs, start, cnt);
+       else
+               ret = -EEXIST;
+       mutex_unlock(&sparse_irq_lock);
+       return ret;
+}
+
+/**
+ * irq_get_next_irq - get next allocated irq number
+ * @offset:    where to start the search
+ *
+ * Returns next irq number after offset or nr_irqs if none is found.
+ */
+unsigned int irq_get_next_irq(unsigned int offset)
+{
+       return find_next_bit(allocated_irqs, nr_irqs, offset);
+}
+
+/**
+ * dynamic_irq_cleanup - cleanup a dynamically allocated irq
+ * @irq:       irq number to initialize
+ */
+void dynamic_irq_cleanup(unsigned int irq)
+{
+       struct irq_desc *desc = irq_to_desc(irq);
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&desc->lock, flags);
+       desc_set_defaults(irq, desc, desc_node(desc));
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 
 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)