From patchwork Thu Jan 20 11:33:35 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 491741 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0KBehG0000754 for ; Thu, 20 Jan 2011 11:42:21 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755648Ab1ATLkP (ORCPT ); Thu, 20 Jan 2011 06:40:15 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:60068 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755582Ab1ATLjM (ORCPT ); Thu, 20 Jan 2011 06:39:12 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by ogre.sisk.pl (Postfix) with ESMTP id 631841A296A; Thu, 20 Jan 2011 12:24:01 +0100 (CET) Received: from ogre.sisk.pl ([127.0.0.1]) by localhost (ogre.sisk.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 19777-02; Thu, 20 Jan 2011 12:23:21 +0100 (CET) Received: from ferrari.rjw.lan (220-bem-13.acn.waw.pl [82.210.184.220]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ogre.sisk.pl (Postfix) with ESMTP id 510261A29A3; Thu, 20 Jan 2011 12:22:55 +0100 (CET) From: "Rafael J. Wysocki" To: Len Brown Subject: [PATCH 7/11] ACPI: Make acpi_os_map_memory() avoid creating unnecessary mappings Date: Thu, 20 Jan 2011 12:33:35 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.38-rc1+; KDE/4.4.4; x86_64; ; ) Cc: Jeff Chua , LKML , ACPI Devel Maling List , "Linux-pm mailing list" , Matthew Garrett References: <201101201226.41021.rjw@sisk.pl> In-Reply-To: <201101201226.41021.rjw@sisk.pl> MIME-Version: 1.0 Message-Id: <201101201233.35621.rjw@sisk.pl> X-Virus-Scanned: amavisd-new at ogre.sisk.pl using MkS_Vir for Linux Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Thu, 20 Jan 2011 11:42:40 +0000 (UTC) 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);