From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH 7/11] ACPI: Make acpi_os_map_memory() avoid creating unnecessary mappings Date: Thu, 20 Jan 2011 12:33:35 +0100 Message-ID: <201101201233.35621.rjw@sisk.pl> References: <201101201226.41021.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201101201226.41021.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org To: Len Brown Cc: Jeff Chua , LKML , ACPI Devel Maling List , Linux-pm mailing list , Matthew Garrett List-Id: linux-acpi@vger.kernel.org From: Rafael J. Wysocki Modify acpi_os_map_memory() so that it doesn't call acpi_os_ioremap() unconditionally every time it is executed (except when acpi_gbl_permanent_mmap is unset), which pretty much defeats the purpose of maintaining the list of ACPI iomaps in osl.c. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/osl.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) Index: linux-2.6/drivers/acpi/osl.c =================================================================== --- linux-2.6.orig/drivers/acpi/osl.c +++ linux-2.6/drivers/acpi/osl.c @@ -302,7 +302,7 @@ acpi_map_lookup_virt(void __iomem *virt, void __iomem *__init_refok acpi_os_map_memory(acpi_physical_address phys, acpi_size size) { - struct acpi_ioremap *map, *tmp_map; + struct acpi_ioremap *map; void __iomem *virt; acpi_physical_address pg_off; acpi_size pg_sz; @@ -315,14 +315,25 @@ acpi_os_map_memory(acpi_physical_address if (!acpi_gbl_permanent_mmap) return __acpi_map_table((unsigned long)phys, size); + mutex_lock(&acpi_ioremap_lock); + /* Check if there's a suitable mapping already. */ + map = acpi_map_lookup(phys, size); + if (map) { + kref_get(&map->ref); + goto out; + } + map = kzalloc(sizeof(*map), GFP_KERNEL); - if (!map) + if (!map) { + mutex_unlock(&acpi_ioremap_lock); return NULL; + } pg_off = round_down(phys, PAGE_SIZE); pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off; virt = acpi_os_ioremap(pg_off, pg_sz); if (!virt) { + mutex_unlock(&acpi_ioremap_lock); kfree(map); return NULL; } @@ -333,19 +344,10 @@ acpi_os_map_memory(acpi_physical_address map->size = pg_sz; kref_init(&map->ref); - mutex_lock(&acpi_ioremap_lock); - /* Check if page has already been mapped. */ - tmp_map = acpi_map_lookup(phys, size); - if (tmp_map) { - kref_get(&tmp_map->ref); - mutex_unlock(&acpi_ioremap_lock); - iounmap(map->virt); - kfree(map); - return tmp_map->virt + (phys - tmp_map->phys); - } list_add_tail_rcu(&map->list, &acpi_ioremaps); - mutex_unlock(&acpi_ioremap_lock); + out: + mutex_unlock(&acpi_ioremap_lock); return map->virt + (phys - map->phys); } EXPORT_SYMBOL_GPL(acpi_os_map_memory);