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authorMyron Stowe <myron.stowe@hp.com>2010-10-21 14:24:09 -0600
committerLen Brown <len.brown@intel.com>2010-10-24 23:28:16 -0400
commit78cdb3ed4053798c894899b15d2255fb880edad4 (patch)
tree351af153f725e4641d10c8ccccf7a2c53896f87d /drivers/acpi
parentd362edaf5386acedad4319a6721bb1540b74dcf7 (diff)
downloadop-kernel-dev-78cdb3ed4053798c894899b15d2255fb880edad4.zip
op-kernel-dev-78cdb3ed4053798c894899b15d2255fb880edad4.tar.gz
ACPI: Convert simple locking to RCU based locking
Convert the simple locking introduced earlier for the ACPI MMIO remappings list to an RCU based locking scheme. Signed-off-by: Myron Stowe <myron.stowe@hp.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/osl.c23
1 files changed, 11 insertions, 12 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index c63d4cb..3282689 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -244,13 +244,13 @@ acpi_physical_address __init acpi_os_get_root_pointer(void)
}
}
-/* Must be called with 'acpi_ioremap_lock' lock held. */
+/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
static void __iomem *
acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size)
{
struct acpi_ioremap *map;
- list_for_each_entry(map, &acpi_ioremaps, list)
+ list_for_each_entry_rcu(map, &acpi_ioremaps, list)
if (map->phys <= phys &&
phys + size <= map->phys + map->size)
return map->virt + (phys - map->phys);
@@ -258,13 +258,13 @@ acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size)
return NULL;
}
-/* Must be called with 'acpi_ioremap_lock' lock held. */
+/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
static struct acpi_ioremap *
acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
{
struct acpi_ioremap *map;
- list_for_each_entry(map, &acpi_ioremaps, list)
+ list_for_each_entry_rcu(map, &acpi_ioremaps, list)
if (map->virt == virt && map->size == size)
return map;
@@ -302,7 +302,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
map->size = size;
spin_lock_irqsave(&acpi_ioremap_lock, flags);
- list_add_tail(&map->list, &acpi_ioremaps);
+ list_add_tail_rcu(&map->list, &acpi_ioremaps);
spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
return virt;
@@ -328,9 +328,10 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
return;
}
- list_del(&map->list);
+ list_del_rcu(&map->list);
spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
+ synchronize_rcu();
iounmap(map->virt);
kfree(map);
}
@@ -584,11 +585,10 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
u32 dummy;
void __iomem *virt_addr;
int size = width / 8, unmap = 0;
- unsigned long flags;
- spin_lock_irqsave(&acpi_ioremap_lock, flags);
+ rcu_read_lock();
virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
- spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
+ rcu_read_unlock();
if (!virt_addr) {
virt_addr = ioremap(phys_addr, size);
unmap = 1;
@@ -621,11 +621,10 @@ acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
{
void __iomem *virt_addr;
int size = width / 8, unmap = 0;
- unsigned long flags;
- spin_lock_irqsave(&acpi_ioremap_lock, flags);
+ rcu_read_lock();
virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
- spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
+ rcu_read_unlock();
if (!virt_addr) {
virt_addr = ioremap(phys_addr, size);
unmap = 1;
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