linux/kernel/irq/irqdesc.c

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/*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006, Thomas Gleixner, Russell King
*
* This file contains the interrupt descriptor management code
*
* Detailed information is available in Documentation/DocBook/genericirq
*
*/
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/radix-tree.h>
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
#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;
#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
static void __init init_irq_default_affinity(void)
{
alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
{
}
#endif
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
#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;
#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;
}
static void desc_smp_init(struct irq_desc *desc, int node)
{
desc->irq_data.node = node;
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_clear(desc->pending_mask);
#endif
}
static inline int desc_node(struct irq_desc *desc)
{
return desc->irq_data.node;
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
}
#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; }
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
#endif
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;
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
desc->name = NULL;
memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
desc_smp_init(desc, node);
}
int nr_irqs = NR_IRQS;
EXPORT_SYMBOL_GPL(nr_irqs);
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
DEFINE_RAW_SPINLOCK(sparse_irq_lock);
static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
#ifdef CONFIG_SPARSE_IRQ
void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
{
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;
}
}
static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
{
radix_tree_insert(&irq_desc_tree, irq, desc);
}
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)
{
void **ptr;
ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
if (ptr)
radix_tree_replace_slot(ptr, desc);
}
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
static void delete_irq_desc(unsigned int irq)
{
radix_tree_delete(&irq_desc_tree, irq);
}
#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
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;
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
struct irq_desc *desc;
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;
if (alloc_masks(desc, gfp, node))
goto err_kstat;
raw_spin_lock_init(&desc->lock);
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
desc_set_defaults(irq, desc, node);
return desc;
err_kstat:
kfree(desc->kstat_irqs);
err_desc:
kfree(desc);
return NULL;
}
static void free_desc(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
unregister_irq_proc(irq, desc);
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
delete_irq_desc(irq);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
free_masks(desc);
kfree(desc->kstat_irqs);
kfree(desc);
}
static int alloc_descs(unsigned int start, unsigned int cnt, int node)
{
struct irq_desc *desc;
unsigned long flags;
int i;
for (i = 0; i < cnt; i++) {
desc = alloc_desc(start + i, node);
if (!desc)
goto err;
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
irq_insert_desc(start + i, desc);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
}
return start;
err:
for (i--; i >= 0; i--)
free_desc(start + i);
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
bitmap_clear(allocated_irqs, start, cnt);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
return -ENOMEM;
}
struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
{
int res = irq_alloc_descs(irq, irq, 1, node);
if (res == -EEXIST || res == irq)
return irq_to_desc(irq);
return NULL;
}
int __init early_irq_init(void)
{
int i, initcnt, node = first_online_node;
struct irq_desc *desc;
init_irq_default_affinity();
/* 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);
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_DEFAULT_INIT_FLAGS,
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
}
};
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;
init_irq_default_affinity();
printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
desc = irq_desc;
count = ARRAY_SIZE(irq_desc);
for (i = 0; i < count; i++) {
desc[i].irq_data.irq = i;
desc[i].irq_data.chip = &no_irq_chip;
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();
}
struct irq_desc *irq_to_desc(unsigned int irq)
{
return (irq < NR_IRQS) ? irq_desc + irq : NULL;
}
struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
{
return irq_to_desc(irq);
}
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
static void free_desc(unsigned int irq)
{
dynamic_irq_cleanup(irq);
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
}
static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
{
return start;
}
#endif /* !CONFIG_SPARSE_IRQ */
genirq: Implement a sane sparse_irq allocator The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 15:48:26 +00:00
/* 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)
{
unsigned long flags;
int i;
if (from >= nr_irqs || (from + cnt) > nr_irqs)
return;
for (i = 0; i < cnt; i++)
free_desc(from + i);
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
bitmap_clear(allocated_irqs, from, cnt);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
}
/**
* 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)
{
unsigned long flags;
int start, ret;
if (!cnt)
return -EINVAL;
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
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);
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
return alloc_descs(start, cnt, node);
err:
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
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 long flags;
unsigned int start;
int ret = 0;
if (!cnt || (from + cnt) > nr_irqs)
return -EINVAL;
raw_spin_lock_irqsave(&sparse_irq_lock, flags);
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;
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
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)
{
struct irq_desc *desc = irq_to_desc(irq);
return desc ? desc->kstat_irqs[cpu] : 0;
}