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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>
hifive-unleashed-5.1
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

View File

@ -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;