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path: root/drivers/acpi/osl.c
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Diffstat (limited to 'drivers/acpi/osl.c')
-rw-r--r--drivers/acpi/osl.c112
1 files changed, 77 insertions, 35 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 762c5d50b8fe..abbf8630f774 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -77,7 +77,10 @@ struct acpi_ioremap {
void __iomem *virt;
acpi_physical_address phys;
acpi_size size;
- unsigned long refcount;
+ union {
+ unsigned long refcount;
+ struct rcu_work rwork;
+ } track;
};
static LIST_HEAD(acpi_ioremaps);
@@ -250,7 +253,7 @@ void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size)
map = acpi_map_lookup(phys, size);
if (map) {
virt = map->virt + (phys - map->phys);
- map->refcount++;
+ map->track.refcount++;
}
mutex_unlock(&acpi_ioremap_lock);
return virt;
@@ -335,7 +338,7 @@ void __iomem __ref
/* Check if there's a suitable mapping already. */
map = acpi_map_lookup(phys, size);
if (map) {
- map->refcount++;
+ map->track.refcount++;
goto out;
}
@@ -358,7 +361,7 @@ void __iomem __ref
map->virt = virt;
map->phys = pg_off;
map->size = pg_sz;
- map->refcount = 1;
+ map->track.refcount = 1;
list_add_tail_rcu(&map->list, &acpi_ioremaps);
@@ -374,41 +377,46 @@ void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);
+static void acpi_os_map_remove(struct acpi_ioremap *map)
+{
+ acpi_unmap(map->phys, map->virt);
+ kfree(map);
+}
+
+static void acpi_os_map_cleanup_deferred(struct work_struct *work)
+{
+ acpi_os_map_remove(container_of(to_rcu_work(work), struct acpi_ioremap,
+ track.rwork));
+}
+
/* Must be called with mutex_lock(&acpi_ioremap_lock) */
-static unsigned long acpi_os_drop_map_ref(struct acpi_ioremap *map)
+static bool acpi_os_drop_map_ref(struct acpi_ioremap *map, bool defer)
{
- unsigned long refcount = --map->refcount;
+ if (--map->track.refcount)
+ return true;
- if (!refcount)
- list_del_rcu(&map->list);
- return refcount;
+ list_del_rcu(&map->list);
+
+ if (defer) {
+ INIT_RCU_WORK(&map->track.rwork, acpi_os_map_cleanup_deferred);
+ queue_rcu_work(system_wq, &map->track.rwork);
+ }
+ return defer;
}
static void acpi_os_map_cleanup(struct acpi_ioremap *map)
{
+ if (!map)
+ return;
+
synchronize_rcu_expedited();
- acpi_unmap(map->phys, map->virt);
- kfree(map);
+ acpi_os_map_remove(map);
}
-/**
- * acpi_os_unmap_iomem - Drop a memory mapping reference.
- * @virt: Start of the address range to drop a reference to.
- * @size: Size of the address range to drop a reference to.
- *
- * Look up the given virtual address range in the list of existing ACPI memory
- * mappings, drop a reference to it and unmap it if there are no more active
- * references to it.
- *
- * During early init (when acpi_permanent_mmap has not been set yet) this
- * routine simply calls __acpi_unmap_table() to get the job done. Since
- * __acpi_unmap_table() is an __init function, the __ref annotation is needed
- * here.
- */
-void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
+static void __ref __acpi_os_unmap_iomem(void __iomem *virt, acpi_size size,
+ bool defer)
{
struct acpi_ioremap *map;
- unsigned long refcount;
if (!acpi_permanent_mmap) {
__acpi_unmap_table(virt, size);
@@ -416,23 +424,56 @@ void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
}
mutex_lock(&acpi_ioremap_lock);
+
map = acpi_map_lookup_virt(virt, size);
if (!map) {
mutex_unlock(&acpi_ioremap_lock);
WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
return;
}
- refcount = acpi_os_drop_map_ref(map);
+ if (acpi_os_drop_map_ref(map, defer))
+ map = NULL;
+
mutex_unlock(&acpi_ioremap_lock);
- if (!refcount)
- acpi_os_map_cleanup(map);
+ acpi_os_map_cleanup(map);
+}
+
+/**
+ * acpi_os_unmap_iomem - Drop a memory mapping reference.
+ * @virt: Start of the address range to drop a reference to.
+ * @size: Size of the address range to drop a reference to.
+ *
+ * Look up the given virtual address range in the list of existing ACPI memory
+ * mappings, drop a reference to it and unmap it if there are no more active
+ * references to it.
+ *
+ * During early init (when acpi_permanent_mmap has not been set yet) this
+ * routine simply calls __acpi_unmap_table() to get the job done. Since
+ * __acpi_unmap_table() is an __init function, the __ref annotation is needed
+ * here.
+ */
+void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
+{
+ __acpi_os_unmap_iomem(virt, size, false);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem);
+/**
+ * acpi_os_unmap_memory - Drop a memory mapping reference.
+ * @virt: Start of the address range to drop a reference to.
+ * @size: Size of the address range to drop a reference to.
+ *
+ * Look up the given virtual address range in the list of existing ACPI memory
+ * mappings, drop a reference to it and if there are no more active references
+ * to it, queue it up for later removal.
+ *
+ * During early init (when acpi_permanent_mmap has not been set yet) this
+ * routine behaves like acpi_os_unmap_iomem().
+ */
void __ref acpi_os_unmap_memory(void *virt, acpi_size size)
{
- return acpi_os_unmap_iomem((void __iomem *)virt, size);
+ __acpi_os_unmap_iomem((void __iomem *)virt, size, true);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
@@ -461,7 +502,6 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
{
u64 addr;
struct acpi_ioremap *map;
- unsigned long refcount;
if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
return;
@@ -472,16 +512,18 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
return;
mutex_lock(&acpi_ioremap_lock);
+
map = acpi_map_lookup(addr, gas->bit_width / 8);
if (!map) {
mutex_unlock(&acpi_ioremap_lock);
return;
}
- refcount = acpi_os_drop_map_ref(map);
+ if (acpi_os_drop_map_ref(map, false))
+ map = NULL;
+
mutex_unlock(&acpi_ioremap_lock);
- if (!refcount)
- acpi_os_map_cleanup(map);
+ acpi_os_map_cleanup(map);
}
EXPORT_SYMBOL(acpi_os_unmap_generic_address);