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ACPI: Convert simple locking to RCU based locking

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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>
This commit is contained in:
Myron Stowe 2010-10-21 14:24:09 -06:00 committed by Len Brown
parent d362edaf53
commit 78cdb3ed40
1 changed files with 11 additions and 12 deletions
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23
drivers/acpi/osl.c
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@ -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 * static void __iomem *
acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size) acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size)
{ {
struct acpi_ioremap *map; 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 && if (map->phys <= phys &&
phys + size <= map->phys + map->size) phys + size <= map->phys + map->size)
return map->virt + (phys - map->phys); return map->virt + (phys - map->phys);
@ -258,13 +258,13 @@ acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size)
return NULL; 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 * static struct acpi_ioremap *
acpi_map_lookup_virt(void __iomem *virt, acpi_size size) acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
{ {
struct acpi_ioremap *map; 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) if (map->virt == virt && map->size == size)
return map; return map;
@ -302,7 +302,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
map->size = size; map->size = size;
spin_lock_irqsave(&acpi_ioremap_lock, flags); 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); spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
return virt; return virt;
@ -328,9 +328,10 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size)
return; return;
} }
list_del(&map->list); list_del_rcu(&map->list);
spin_unlock_irqrestore(&acpi_ioremap_lock, flags); spin_unlock_irqrestore(&acpi_ioremap_lock, flags);
synchronize_rcu();
iounmap(map->virt); iounmap(map->virt);
kfree(map); kfree(map);
} }
@ -584,11 +585,10 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
u32 dummy; u32 dummy;
void __iomem *virt_addr; void __iomem *virt_addr;
int size = width / 8, unmap = 0; 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); virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
spin_unlock_irqrestore(&acpi_ioremap_lock, flags); rcu_read_unlock();
if (!virt_addr) { if (!virt_addr) {
virt_addr = ioremap(phys_addr, size); virt_addr = ioremap(phys_addr, size);
unmap = 1; unmap = 1;
@ -621,11 +621,10 @@ acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
{ {
void __iomem *virt_addr; void __iomem *virt_addr;
int size = width / 8, unmap = 0; 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); virt_addr = acpi_map_vaddr_lookup(phys_addr, size);
spin_unlock_irqrestore(&acpi_ioremap_lock, flags); rcu_read_unlock();
if (!virt_addr) { if (!virt_addr) {
virt_addr = ioremap(phys_addr, size); virt_addr = ioremap(phys_addr, size);
unmap = 1; unmap = 1;