From owner-svn-src-all@FreeBSD.ORG  Fri Aug 17 14:14:26 2012
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 513DF106564A;
	Fri, 17 Aug 2012 14:14:26 +0000 (UTC) (envelope-from jhb@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 3D2528FC12;
	Fri, 17 Aug 2012 14:14:26 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q7HEEQuB079982;
	Fri, 17 Aug 2012 14:14:26 GMT (envelope-from jhb@svn.freebsd.org)
Received: (from jhb@localhost)
	by svn.freebsd.org (8.14.4/8.14.4/Submit) id q7HEEQl5079980;
	Fri, 17 Aug 2012 14:14:26 GMT (envelope-from jhb@svn.freebsd.org)
Message-Id: <201208171414.q7HEEQl5079980@svn.freebsd.org>
From: John Baldwin <jhb@FreeBSD.org>
Date: Fri, 17 Aug 2012 14:14:26 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r239354 - head/sys/x86/x86
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
	user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 17 Aug 2012 14:14:26 -0000

Author: jhb
Date: Fri Aug 17 14:14:25 2012
New Revision: 239354
URL: http://svn.freebsd.org/changeset/base/239354

Log:
  Allow static DMA allocations that allow for enough segments to do page-sized
  segments for the entire allocation to use kmem_alloc_attr() to allocate
  KVM rather than using kmem_alloc_contig().  This avoids requiring
  a single physically contiguous chunk in this case.
  
  Submitted by:	Peter Jeremy (original version)
  MFC after:	1 month

Modified:
  head/sys/x86/x86/busdma_machdep.c

Modified: head/sys/x86/x86/busdma_machdep.c
==============================================================================
--- head/sys/x86/x86/busdma_machdep.c	Fri Aug 17 05:51:46 2012	(r239353)
+++ head/sys/x86/x86/busdma_machdep.c	Fri Aug 17 14:14:25 2012	(r239354)
@@ -533,13 +533,14 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, voi
 	    dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 	    attr == VM_MEMATTR_DEFAULT) {
 		*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
+	} else if (dmat->nsegments >= btoc(dmat->maxsize) &&
+	    dmat->alignment <= PAGE_SIZE &&
+	    (dmat->boundary == 0 || dmat->boundary >= dmat->lowaddr)) {
+		/* Page-based multi-segment allocations allowed */
+		*vaddr = (void *)kmem_alloc_attr(kernel_map, dmat->maxsize,
+		    mflags, 0ul, dmat->lowaddr, attr);
+		*mapp = &contig_dmamap;
 	} else {
-		/*
-		 * XXX Use Contigmalloc until it is merged into this facility
-		 *     and handles multi-seg allocations.  Nobody is doing
-		 *     multi-seg allocations yet though.
-		 * XXX Certain AGP hardware does.
-		 */
 		*vaddr = (void *)kmem_alloc_contig(kernel_map, dmat->maxsize,
 		    mflags, 0ul, dmat->lowaddr, dmat->alignment ?
 		    dmat->alignment : 1ul, dmat->boundary, attr);