Commit 78cdb3ed authored by Myron Stowe's avatar Myron Stowe Committed by Len Brown
Browse files

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: default avatarMyron Stowe <myron.stowe@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent d362edaf

drivers/acpi/osl.c

+11 −12
Original line number Diff line number Diff line
@@ -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;