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authorRafael J. Wysocki <rjw@sisk.pl>2011-02-08 23:38:05 +0100
committerRafael J. Wysocki <rjw@sisk.pl>2011-02-24 19:58:41 +0100
commit7ffd0443f2502478545e23e194b7eb8e16376072 (patch)
tree467a47d0d8b9ce4de3c95aa11d25b8c9b5ce05a1 /drivers/acpi/osl.c
parent7fe135dc058faea0ce319a03e3b6f98c5049955c (diff)
ACPI: Make acpi_os_map_memory() avoid creating unnecessary mappings
Modify acpi_os_map_memory() so that it doesn't call acpi_os_ioremap() unconditionally every time it is executed (except when acpi_gbl_permanent_mmap is unset), which pretty much defeats the purpose of maintaining the list of ACPI iomaps in osl.c. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/acpi/osl.c')
-rw-r--r--drivers/acpi/osl.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index f6785bced21..445f205752a 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -302,7 +302,7 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
void __iomem *__init_refok
acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
- struct acpi_ioremap *map, *tmp_map;
+ struct acpi_ioremap *map;
void __iomem *virt;
acpi_physical_address pg_off;
acpi_size pg_sz;
@@ -315,14 +315,25 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
if (!acpi_gbl_permanent_mmap)
return __acpi_map_table((unsigned long)phys, size);
+ mutex_lock(&acpi_ioremap_lock);
+ /* Check if there's a suitable mapping already. */
+ map = acpi_map_lookup(phys, size);
+ if (map) {
+ kref_get(&map->ref);
+ goto out;
+ }
+
map = kzalloc(sizeof(*map), GFP_KERNEL);
- if (!map)
+ if (!map) {
+ mutex_unlock(&acpi_ioremap_lock);
return NULL;
+ }
pg_off = round_down(phys, PAGE_SIZE);
pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off;
virt = acpi_os_ioremap(pg_off, pg_sz);
if (!virt) {
+ mutex_unlock(&acpi_ioremap_lock);
kfree(map);
return NULL;
}
@@ -333,19 +344,10 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
map->size = pg_sz;
kref_init(&map->ref);
- mutex_lock(&acpi_ioremap_lock);
- /* Check if page has already been mapped. */
- tmp_map = acpi_map_lookup(phys, size);
- if (tmp_map) {
- kref_get(&tmp_map->ref);
- mutex_unlock(&acpi_ioremap_lock);
- iounmap(map->virt);
- kfree(map);
- return tmp_map->virt + (phys - tmp_map->phys);
- }
list_add_tail_rcu(&map->list, &acpi_ioremaps);
- mutex_unlock(&acpi_ioremap_lock);
+ out:
+ mutex_unlock(&acpi_ioremap_lock);
return map->virt + (phys - map->phys);
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);