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irq_domain/powerpc: eliminate irq_map; use irq_alloc_desc() instead

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This patch drops the powerpc-specific irq_map table and replaces it with
directly using the irq_alloc_desc()/irq_free_desc() interfaces for allocating
and freeing irq_desc structures.

This patch is a preparation step for generalizing the powerpc-specific virq
infrastructure to become irq_domains.

As part of this change, the irq_big_lock is changed to a mutex from a raw
spinlock.  There is no longer any need to use a spin lock since the irq_desc
allocation code is now responsible for the critical section of finding
an unused range of irq numbers.

The radix lookup table is also changed to store the irq_data pointer instead
of the irq_map entry since the irq_map is removed.  This should end up being
functionally equivalent since only allocated irq_descs are ever added to the
radix tree.

v5: - Really don't ever allocate virq 0.  The previous version could still
      do it if hint == 0
    - Respect irq_virq_count setting for NOMAP.  Some NOMAP domains cannot
      use virq values above irq_virq_count.
    - Use numa_node_id() when allocating irq_descs.  Ideally the API should
      obtain that value from the caller, but that touches a lot of call sites
      so will be deferred to a follow-on patch.
    - Fix irq_find_mapping() to include irq numbers lower than
      NUM_ISA_INTERRUPTS.  With the switch to irq_alloc_desc*(), the lowest
      possible allocated irq is now returned by arch_probe_nr_irqs().
v4: - Fix incorrect access to irq_data structure in debugfs code
    - Don't ever allocate virq 0

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Grant Likely 2012-02-14 14:06:51 -07:00
parent bae1d8f199
commit 4bbdd45afd
2 changed files with 69 additions and 198 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
arch/powerpc/include/asm/irq.h
View file

@ -191,33 +191,6 @@ extern unsigned int irq_linear_revmap(struct irq_domain *host,
irq_hw_number_t hwirq);
/**
* irq_alloc_virt - Allocate virtual irq numbers
* @host: host owning these new virtual irqs
* @count: number of consecutive numbers to allocate
* @hint: pass a hint number, the allocator will try to use a 1:1 mapping
*
* This is a low level function that is used internally by irq_create_mapping()
* and that can be used by some irq controllers implementations for things
* like allocating ranges of numbers for MSIs. The revmaps are left untouched.
*/
extern unsigned int irq_alloc_virt(struct irq_domain *host,
unsigned int count,
unsigned int hint);
/**
* irq_free_virt - Free virtual irq numbers
* @virq: virtual irq number of the first interrupt to free
* @count: number of interrupts to free
*
* This function is the opposite of irq_alloc_virt. It will not clear reverse
* maps, this should be done previously by unmap'ing the interrupt. In fact,
* all interrupts covered by the range being freed should have been unmapped
* prior to calling this.
*/
extern void irq_free_virt(unsigned int virq, unsigned int count);
/**
* irq_early_init - Init irq remapping subsystem
*/

240
arch/powerpc/kernel/irq.c
View file

@ -491,38 +491,29 @@ void do_softirq(void)
* 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_domain *host;
};
static LIST_HEAD(irq_domain_list);
static DEFINE_RAW_SPINLOCK(irq_big_lock);
static DEFINE_MUTEX(irq_domain_mutex);
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_domain *irq_default_host;
irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
{
return irq_map[d->irq].hwirq;
return d->hwirq;
}
EXPORT_SYMBOL_GPL(irqd_to_hwirq);
irq_hw_number_t virq_to_hw(unsigned int virq)
{
return irq_map[virq].hwirq;
struct irq_data *irq_data = irq_get_irq_data(virq);
return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
}
EXPORT_SYMBOL_GPL(virq_to_hw);
bool virq_is_host(unsigned int virq, struct irq_domain *host)
{
return irq_map[virq].host == host;
struct irq_data *irq_data = irq_get_irq_data(virq);
return irq_data ? irq_data->domain == host : false;
}
EXPORT_SYMBOL_GPL(virq_is_host);
@ -537,11 +528,10 @@ struct irq_domain *irq_alloc_host(struct device_node *of_node,
struct irq_domain_ops *ops,
irq_hw_number_t inval_irq)
{
struct irq_domain *host;
struct irq_domain *host, *h;
unsigned int size = sizeof(struct irq_domain);
unsigned int i;
unsigned int *rmap;
unsigned long flags;
/* Allocate structure and revmap table if using linear mapping */
if (revmap_type == IRQ_DOMAIN_MAP_LINEAR)
@ -559,23 +549,20 @@ struct irq_domain *irq_alloc_host(struct device_node *of_node,
if (host->ops->match == NULL)
host->ops->match = default_irq_host_match;
raw_spin_lock_irqsave(&irq_big_lock, flags);
/* If it's a legacy controller, check for duplicates and
* mark it as allocated (we use irq 0 host pointer for that
*/
mutex_lock(&irq_domain_mutex);
/* Make sure only one legacy controller can be created */
if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
if (irq_map[0].host != NULL) {
raw_spin_unlock_irqrestore(&irq_big_lock, flags);
of_node_put(host->of_node);
kfree(host);
return NULL;
list_for_each_entry(h, &irq_domain_list, link) {
if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
mutex_unlock(&irq_domain_mutex);
of_node_put(host->of_node);
kfree(host);
return NULL;
}
}
irq_map[0].host = host;
}
list_add(&host->link, &irq_domain_list);
raw_spin_unlock_irqrestore(&irq_big_lock, flags);
mutex_unlock(&irq_domain_mutex);
/* Additional setups per revmap type */
switch(revmap_type) {
@ -584,10 +571,9 @@ struct irq_domain *irq_alloc_host(struct device_node *of_node,
host->inval_irq = 0;
/* setup us as the host for all legacy interrupts */
for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
irq_map[i].hwirq = i;
smp_wmb();
irq_map[i].host = host;
smp_wmb();
struct irq_data *irq_data = irq_get_irq_data(i);
irq_data->hwirq = i;
irq_data->domain = host;
/* Legacy flags are left to default at this point,
* one can then use irq_create_mapping() to
@ -604,7 +590,6 @@ struct irq_domain *irq_alloc_host(struct device_node *of_node,
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_DOMAIN_MAP_TREE:
@ -622,20 +607,19 @@ struct irq_domain *irq_alloc_host(struct device_node *of_node,
struct irq_domain *irq_find_host(struct device_node *node)
{
struct irq_domain *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);
mutex_lock(&irq_domain_mutex);
list_for_each_entry(h, &irq_domain_list, link)
if (h->ops->match(h, node)) {
found = h;
break;
}
raw_spin_unlock_irqrestore(&irq_big_lock, flags);
mutex_unlock(&irq_domain_mutex);
return found;
}
EXPORT_SYMBOL_GPL(irq_find_host);
@ -659,33 +643,20 @@ void irq_set_virq_count(unsigned int count)
static int irq_setup_virq(struct irq_domain *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();
struct irq_data *irq_data = irq_get_irq_data(virq);
irq_data->hwirq = hwirq;
irq_data->domain = host;
if (host->ops->map(host, virq, hwirq)) {
pr_debug("irq: -> mapping failed, freeing\n");
goto errdesc;
irq_data->domain = NULL;
irq_data->hwirq = 0;
return -1;
}
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_domain *host)
@ -698,16 +669,24 @@ unsigned int irq_create_direct_mapping(struct irq_domain *host)
BUG_ON(host == NULL);
WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
virq = irq_alloc_virt(host, 1, 0);
virq = irq_alloc_desc_from(1, 0);
if (virq == NO_IRQ) {
pr_debug("irq: create_direct virq allocation failed\n");
return NO_IRQ;
}
if (virq >= irq_virq_count) {
pr_err("ERROR: no free irqs available below %i maximum\n",
irq_virq_count);
irq_free_desc(virq);
return 0;
}
pr_debug("irq: create_direct obtained virq %d\n", virq);
if (irq_setup_virq(host, virq, virq))
if (irq_setup_virq(host, virq, virq)) {
irq_free_desc(virq);
return NO_IRQ;
}
return virq;
}
@ -747,15 +726,22 @@ unsigned int irq_create_mapping(struct irq_domain *host,
} else {
/* Allocate a virtual interrupt number */
hint = hwirq % irq_virq_count;
virq = irq_alloc_virt(host, 1, hint);
if (hint == 0)
hint = 1;
virq = irq_alloc_desc_from(hint, 0);
if (!virq)
virq = irq_alloc_desc_from(1, 0);
if (virq == NO_IRQ) {
pr_debug("irq: -> virq allocation failed\n");
return NO_IRQ;
}
}
if (irq_setup_virq(host, virq, hwirq))
if (irq_setup_virq(host, virq, hwirq)) {
if (host->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
irq_free_desc(virq);
return NO_IRQ;
}
pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
hwirq, host->of_node ? host->of_node->full_name : "null", virq);
@ -806,13 +792,14 @@ EXPORT_SYMBOL_GPL(irq_create_of_mapping);
void irq_dispose_mapping(unsigned int virq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);
struct irq_domain *host;
irq_hw_number_t hwirq;
if (virq == NO_IRQ)
if (virq == NO_IRQ || !irq_data)
return;
host = irq_map[virq].host;
host = irq_data->domain;
if (WARN_ON(host == NULL))
return;
@ -834,7 +821,7 @@ void irq_dispose_mapping(unsigned int virq)
smp_mb();
/* Clear reverse map */
hwirq = irq_map[virq].hwirq;
hwirq = irq_data->hwirq;
switch(host->revmap_type) {
case IRQ_DOMAIN_MAP_LINEAR:
if (hwirq < host->revmap_data.linear.size)
@ -848,12 +835,9 @@ void irq_dispose_mapping(unsigned int virq)
}
/* Destroy map */
smp_mb();
irq_map[virq].hwirq = host->inval_irq;
irq_data->hwirq = host->inval_irq;
irq_free_descs(virq, 1);
/* Free it */
irq_free_virt(virq, 1);
irq_free_desc(virq);
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);
@ -874,16 +858,16 @@ unsigned int irq_find_mapping(struct irq_domain *host,
return hwirq;
/* Slow path does a linear search of the map */
if (hint < NUM_ISA_INTERRUPTS)
hint = NUM_ISA_INTERRUPTS;
if (hint == 0)
hint = 1;
i = hint;
do {
if (irq_map[i].host == host &&
irq_map[i].hwirq == hwirq)
do {
struct irq_data *data = irq_get_irq_data(i);
if (data && (data->domain == host) && (data->hwirq == hwirq))
return i;
i++;
if (i >= irq_virq_count)
i = NUM_ISA_INTERRUPTS;
i = 1;
} while(i != hint);
return NO_IRQ;
}
@ -928,19 +912,17 @@ int irq_choose_cpu(const struct cpumask *mask)
unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
irq_hw_number_t hwirq)
{
struct irq_map_entry *ptr;
unsigned int virq;
struct irq_data *irq_data;
if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_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
* 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);
irq_data = radix_tree_lookup(&host->revmap_data.tree, hwirq);
rcu_read_unlock();
/*
@ -948,24 +930,20 @@ unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
* 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;
return irq_data ? irq_data->irq : irq_find_mapping(host, hwirq);
}
void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
irq_hw_number_t hwirq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);
if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
return;
if (virq != NO_IRQ) {
mutex_lock(&revmap_trees_mutex);
radix_tree_insert(&host->revmap_data.tree, hwirq,
&irq_map[virq]);
radix_tree_insert(&host->revmap_data.tree, hwirq, irq_data);
mutex_unlock(&revmap_trees_mutex);
}
}
@ -994,86 +972,6 @@ unsigned int irq_linear_revmap(struct irq_domain *host,
return revmap[hwirq];
}
unsigned int irq_alloc_virt(struct irq_domain *host,
unsigned int count,
unsigned int hint)
{
unsigned long flags;
unsigned int i, j, found = NO_IRQ;
if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
return NO_IRQ;
raw_spin_lock_irqsave(&irq_big_lock, flags);
/* Use hint for 1 interrupt if any */
if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
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 = NUM_ISA_INTERRUPTS, 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 < NUM_ISA_INTERRUPTS);
WARN_ON (count == 0 || (virq + count) > irq_virq_count);
if (virq < NUM_ISA_INTERRUPTS) {
if (virq + count < NUM_ISA_INTERRUPTS)
return;
count =- NUM_ISA_INTERRUPTS - virq;
virq = NUM_ISA_INTERRUPTS;
}
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_domain *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);
}
int arch_early_irq_init(void)
{
return 0;
@ -1103,7 +1001,7 @@ static int virq_debug_show(struct seq_file *m, void *private)
struct irq_chip *chip;
seq_printf(m, "%5d ", i);
seq_printf(m, "0x%05lx ", irq_map[i].hwirq);
seq_printf(m, "0x%05lx ", desc->irq_data.hwirq);
chip = irq_desc_get_chip(desc);
if (chip && chip->name)
@ -1115,8 +1013,8 @@ static int virq_debug_show(struct seq_file *m, void *private)
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;
if (desc->irq_data.domain->of_node)
p = desc->irq_data.domain->of_node->full_name;
else
p = none;
seq_printf(m, "%s\n", p);