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ACPI: Do not use krefs under a mutex in osl.c

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The reference counting of ACPI iomaps is carried out entirely under
acpi_ioremap_lock, so it is sufficient to use simple counters instead
of krefs for this purpose.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Rafael J. Wysocki 2011-02-08 23:38:15 +01:00
parent 7ffd0443f2
commit b7c1fadd6c
1 changed files with 16 additions and 20 deletions
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28
drivers/acpi/osl.c
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@ -105,7 +105,7 @@ struct acpi_ioremap {
void __iomem *virt; void __iomem *virt;
acpi_physical_address phys; acpi_physical_address phys;
acpi_size size; acpi_size size;
struct kref ref; unsigned long refcount;
}; };
static LIST_HEAD(acpi_ioremaps); static LIST_HEAD(acpi_ioremaps);
@ -319,7 +319,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
/* Check if there's a suitable mapping already. */ /* Check if there's a suitable mapping already. */
map = acpi_map_lookup(phys, size); map = acpi_map_lookup(phys, size);
if (map) { if (map) {
kref_get(&map->ref); map->refcount++;
goto out; goto out;
} }
@ -342,7 +342,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
map->virt = virt; map->virt = virt;
map->phys = pg_off; map->phys = pg_off;
map->size = pg_sz; map->size = pg_sz;
kref_init(&map->ref); map->refcount = 1;
list_add_tail_rcu(&map->list, &acpi_ioremaps); list_add_tail_rcu(&map->list, &acpi_ioremaps);
@ -352,25 +352,24 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
} }
EXPORT_SYMBOL_GPL(acpi_os_map_memory); EXPORT_SYMBOL_GPL(acpi_os_map_memory);
static void acpi_kref_del_iomap(struct kref *ref) static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
{ {
struct acpi_ioremap *map; if (!--map->refcount)
map = container_of(ref, struct acpi_ioremap, ref);
list_del_rcu(&map->list); list_del_rcu(&map->list);
} }
static void acpi_os_remove_map(struct acpi_ioremap *map) static void acpi_os_map_cleanup(struct acpi_ioremap *map)
{ {
if (!map->refcount) {
synchronize_rcu(); synchronize_rcu();
iounmap(map->virt); iounmap(map->virt);
kfree(map); kfree(map);
}
} }
void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
{ {
struct acpi_ioremap *map; struct acpi_ioremap *map;
int del;
if (!acpi_gbl_permanent_mmap) { if (!acpi_gbl_permanent_mmap) {
__acpi_unmap_table(virt, size); __acpi_unmap_table(virt, size);
@ -384,11 +383,10 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
WARN(true, PREFIX "%s: bad address %p\n", __func__, virt); WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
return; return;
} }
del = kref_put(&map->ref, acpi_kref_del_iomap); acpi_os_drop_map_ref(map);
mutex_unlock(&acpi_ioremap_lock); mutex_unlock(&acpi_ioremap_lock);
if (del) acpi_os_map_cleanup(map);
acpi_os_remove_map(map);
} }
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory); EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
@ -418,7 +416,6 @@ static int acpi_os_map_generic_address(struct acpi_generic_address *addr)
static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr) static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr)
{ {
struct acpi_ioremap *map; struct acpi_ioremap *map;
int del;
if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
return; return;
@ -432,11 +429,10 @@ static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr)
mutex_unlock(&acpi_ioremap_lock); mutex_unlock(&acpi_ioremap_lock);
return; return;
} }
del = kref_put(&map->ref, acpi_kref_del_iomap); acpi_os_drop_map_ref(map);
mutex_unlock(&acpi_ioremap_lock); mutex_unlock(&acpi_ioremap_lock);
if (del) acpi_os_map_cleanup(map);
acpi_os_remove_map(map);
} }
#ifdef ACPI_FUTURE_USAGE #ifdef ACPI_FUTURE_USAGE