[src/trunk]: src/sys/arch/x86/x86 In bus_dma_tag_create(9), copy important pr...

[dyoung <dyoung%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f00f5ce84dad
branches:  trunk
changeset: 769960:f00f5ce84dad
user:      dyoung <dyoung%NetBSD.org@localhost>
date:      Wed Sep 28 01:35:58 2011 +0000

description:
In bus_dma_tag_create(9), copy important properties (e.g., bounce
parameters) from the parent tag.

In bus_dma_tag_create(), increase the reference count on a parent
bus_dma_tag_t (if applicable), and decrease the reference count in
bus_dma_tag_destroy().

Don't let bus_dmatag_destroy(9) destroy an overridden bus_dma_tag_t.

diffstat:

 sys/arch/x86/x86/bus_dma.c |  12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diffs (47 lines):

diff -r ec6a24a69224 -r f00f5ce84dad sys/arch/x86/x86/bus_dma.c
--- a/sys/arch/x86/x86/bus_dma.c        Wed Sep 28 01:33:26 2011 +0000
+++ b/sys/arch/x86/x86/bus_dma.c        Wed Sep 28 01:35:58 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bus_dma.c,v 1.64 2011/09/28 01:33:26 dyoung Exp $      */
+/*     $NetBSD: bus_dma.c,v 1.65 2011/09/28 01:35:58 dyoung Exp $      */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2007 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.64 2011/09/28 01:33:26 dyoung Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.65 2011/09/28 01:35:58 dyoung Exp $");
 
 /*
  * The following is included because _bus_dma_uiomove is derived from
@@ -1623,6 +1623,8 @@
 void
 bus_dma_tag_destroy(bus_dma_tag_t bdt)
 {
+       if (bdt->bdt_super != NULL)
+               bus_dmatag_destroy(bdt->bdt_super);
        kmem_free(bdt, sizeof(struct x86_bus_dma_tag));
 }
 
@@ -1642,6 +1644,10 @@
        if (bdt == NULL)
                return ENOMEM;
 
+       *bdt = *obdt;
+       /* don't let bus_dmatag_destroy free these */
+       bdt->_tag_needs_free = 0;
+
        bdt->bdt_super = obdt;
 
        for (bits = present; bits != 0; bits = nbits) {
@@ -1661,6 +1667,8 @@
        bdt->bdt_ctx = ctx;
 
        *bdtp = bdt;
+       if (obdt->_tag_needs_free)
+               obdt->_tag_needs_free++;
 
        return 0;
 einval: