From 7fe135dc058faea0ce319a03e3b6f98c5049955c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 8 Feb 2011 23:37:53 +0100 Subject: [PATCH] ACPI: Avoid walking the list of memory mappings in osl.c twice in a row Make acpi_os_unmap_generic_address() use acpi_map_lookup() to find the desired iomap and drop the reference to it directly (and eventually remove it if necessary) instead of calling acpi_os_unmap_memory(), which requires us to walk the list of ACPI iomaps twice in a row (first, to get the virtual address associated with the iomap and second, to get the iomap itself). Signed-off-by: Rafael J. Wysocki --- drivers/acpi/osl.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 97061928249a..f6785bced215 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -358,6 +358,13 @@ static void acpi_kref_del_iomap(struct kref *ref) list_del_rcu(&map->list); } +static void acpi_os_remove_map(struct acpi_ioremap *map) +{ + synchronize_rcu(); + iounmap(map->virt); + kfree(map); +} + void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) { struct acpi_ioremap *map; @@ -372,20 +379,14 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) map = acpi_map_lookup_virt(virt, size); if (!map) { mutex_unlock(&acpi_ioremap_lock); - printk(KERN_ERR PREFIX "%s: bad address %p\n", __func__, virt); - dump_stack(); + WARN(true, PREFIX "%s: bad address %p\n", __func__, virt); return; } - del = kref_put(&map->ref, acpi_kref_del_iomap); mutex_unlock(&acpi_ioremap_lock); - if (!del) - return; - - synchronize_rcu(); - iounmap(map->virt); - kfree(map); + if (del) + acpi_os_remove_map(map); } EXPORT_SYMBOL_GPL(acpi_os_unmap_memory); @@ -414,8 +415,8 @@ static int acpi_os_map_generic_address(struct acpi_generic_address *addr) static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr) { - void __iomem *virt; - acpi_size size = addr->bit_width / 8; + struct acpi_ioremap *map; + int del; if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) return; @@ -424,10 +425,16 @@ static void acpi_os_unmap_generic_address(struct acpi_generic_address *addr) return; mutex_lock(&acpi_ioremap_lock); - virt = acpi_map_vaddr_lookup(addr->address, size); + map = acpi_map_lookup(addr->address, addr->bit_width / 8); + if (!map) { + mutex_unlock(&acpi_ioremap_lock); + return; + } + del = kref_put(&map->ref, acpi_kref_del_iomap); mutex_unlock(&acpi_ioremap_lock); - acpi_os_unmap_memory(virt, size); + if (del) + acpi_os_remove_map(map); } #ifdef ACPI_FUTURE_USAGE