From patchwork Wed Oct 13 16:15:15 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Helgaas X-Patchwork-Id: 250971 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 o9DGGdBR008472 for ; Wed, 13 Oct 2010 16:16:40 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752036Ab0JMQPS (ORCPT ); Wed, 13 Oct 2010 12:15:18 -0400 Received: from g1t0028.austin.hp.com ([15.216.28.35]:24499 "EHLO g1t0028.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751878Ab0JMQPR (ORCPT ); Wed, 13 Oct 2010 12:15:17 -0400 Received: from g1t0038.austin.hp.com (g1t0038.austin.hp.com [16.236.32.44]) by g1t0028.austin.hp.com (Postfix) with ESMTP id 964F71C028; Wed, 13 Oct 2010 16:15:16 +0000 (UTC) Received: from ldl (ldl.usa.hp.com [16.125.112.222]) by g1t0038.austin.hp.com (Postfix) with ESMTP id 5DC953005B; Wed, 13 Oct 2010 16:15:16 +0000 (UTC) Received: from localhost (ldl.fc.hp.com [127.0.0.1]) by ldl (Postfix) with ESMTP id 3A648CF0009; Wed, 13 Oct 2010 10:15:16 -0600 (MDT) Received: from ldl ([127.0.0.1]) by localhost (ldl.fc.hp.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WMDY2MMRCAAU; Wed, 13 Oct 2010 10:15:16 -0600 (MDT) Received: from eh.fc.hp.com (bob.lnx.usa.hp.com [16.125.112.218]) by ldl (Postfix) with ESMTP id 06669CF0007; Wed, 13 Oct 2010 10:15:16 -0600 (MDT) Received: from bob.kio (localhost [127.0.0.1]) by eh.fc.hp.com (Postfix) with ESMTP id E2A2E406039; Wed, 13 Oct 2010 10:15:15 -0600 (MDT) Subject: [PATCH v3 2/6] resources: allocate space within a region from the top down To: Jesse Barnes From: Bjorn Helgaas Cc: Bob Picco , Brian Bloniarz , Charles Butterfield , Denys Vlasenko , linux-pci@vger.kernel.org, "Horst H. von Brand" , linux-kernel@vger.kernel.org, Stefan Becker , "H. Peter Anvin" , Yinghai Lu , Thomas Gleixner , Linus Torvalds , Ingo Molnar Date: Wed, 13 Oct 2010 10:15:15 -0600 Message-ID: <20101013161515.28476.99253.stgit@bob.kio> In-Reply-To: <20101013161359.28476.6050.stgit@bob.kio> References: <20101013161359.28476.6050.stgit@bob.kio> User-Agent: StGit/0.15 MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Wed, 13 Oct 2010 16:16:40 +0000 (UTC) diff --git a/kernel/resource.c b/kernel/resource.c index ace2269..9218e8e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -357,8 +357,77 @@ int __weak page_is_ram(unsigned long pfn) return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1; } +#ifdef ARCH_HAS_TOP_DOWN_ALLOC +/* + * Find the resource before "child" in the sibling list of "root" children. + */ +static struct resource *find_sibling_prev(struct resource *root, struct resource *child) +{ + struct resource *this; + + for (this = root->child; this; this = this->sibling) + if (this->sibling == child) + return this; + + return NULL; +} + /* * Find empty slot in the resource tree given range and alignment. + * This version allocates from the end of the root resource first. + */ +static int find_resource(struct resource *root, struct resource *new, + resource_size_t size, resource_size_t min, + resource_size_t max, resource_size_t align, + resource_size_t (*alignf)(void *, + const struct resource *, + resource_size_t, + resource_size_t), + void *alignf_data) +{ + struct resource *this; + struct resource tmp = *new; + resource_size_t start; + + tmp.start = root->end; + tmp.end = root->end; + + this = find_sibling_prev(root, NULL); + for (;;) { + if (this && this->end < root->end) + tmp.start = this->end + 1; + else + tmp.start = root->start; + if (tmp.start < min) + tmp.start = min; + if (tmp.end > max) + tmp.end = max; + tmp.start = ALIGN(tmp.start, align); + if (alignf) { + start = alignf(alignf_data, &tmp, size, align); + if (tmp.start <= start && start <= tmp.end) + tmp.start = start; + else + tmp.start = tmp.end; + } + if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) { + new->start = tmp.start; + new->end = tmp.start + size - 1; + return 0; + } + if (!this || this->start == root->start) + break; + tmp.end = this->start - 1; + this = find_sibling_prev(root, this); + } + return -EBUSY; +} + +#else + +/* + * Find empty slot in the resource tree given range and alignment. + * This version allocates from the beginning of the root resource first. */ static int find_resource(struct resource *root, struct resource *new, resource_size_t size, resource_size_t min, @@ -411,6 +480,7 @@ static int find_resource(struct resource *root, struct resource *new, } return -EBUSY; } +#endif /** * allocate_resource - allocate empty slot in the resource tree given range & alignment