svn commit: r235105 - in projects/altix2/sys: kern sys

[Marcel Moolenaar]

Author: marcel
Date: Sun May  6 20:37:02 2012
New Revision: 235105
URL: http://svn.freebsd.org/changeset/base/235105

Log:
  Implement busdma_tag_derive().

Modified:
  projects/altix2/sys/kern/subr_busdma.c
  projects/altix2/sys/sys/busdma.h

Modified: projects/altix2/sys/kern/subr_busdma.c
==============================================================================
--- projects/altix2/sys/kern/subr_busdma.c	Sun May  6 20:26:28 2012	(r235104)
+++ projects/altix2/sys/kern/subr_busdma.c	Sun May  6 20:37:02 2012	(r235105)
@@ -37,6 +37,8 @@ __FBSDID("$FreeBSD$");
 
 struct busdma_tag {
 	struct busdma_tag *dt_chain;
+	struct busdma_tag *dt_child;
+	struct busdma_tag *dt_parent;
 	device_t	dt_device;
 	bus_addr_t	dt_minaddr;
 	bus_addr_t	dt_maxaddr;
@@ -93,7 +95,7 @@ _busdma_tag_get_base(device_t dev)
 
 static int
 _busdma_tag_make(device_t dev, busdma_tag_t base, bus_addr_t maxaddr,
-    bus_addr_t align, bus_addr_t bndry, bus_addr_t maxsz, u_int nsegs,
+    bus_addr_t align, bus_addr_t bndry, bus_size_t maxsz, u_int nsegs,
     bus_size_t maxsegsz, u_int flags, busdma_tag_t *tag_p)
 {
 	busdma_tag_t tag;
@@ -122,7 +124,7 @@ _busdma_tag_make(device_t dev, busdma_ta
 
 int
 busdma_tag_create(device_t dev, bus_addr_t maxaddr, bus_addr_t align,
-    bus_addr_t bndry, bus_addr_t maxsz, u_int nsegs, bus_size_t maxsegsz,
+    bus_addr_t bndry, bus_size_t maxsz, u_int nsegs, bus_size_t maxsegsz,
     u_int flags, busdma_tag_t *tag_p)
 {
 	busdma_tag_t base, first, tag;
@@ -142,3 +144,26 @@ busdma_tag_create(device_t dev, bus_addr
 	*tag_p = tag;
 	return (0);
 }
+
+int
+busdma_tag_derive(busdma_tag_t base, bus_addr_t maxaddr, bus_addr_t align,
+    bus_addr_t bndry, bus_size_t maxsz, u_int nsegs, bus_size_t maxsegsz,
+    u_int flags, busdma_tag_t *tag_p)
+{
+	busdma_tag_t tag;
+	int error;
+
+	error = _busdma_tag_make(base->dt_device, base, maxaddr, align, bndry,
+	    maxsz, nsegs, maxsegsz, flags, &tag);
+	if (error != 0)
+		return (error);
+
+	/*
+	 * This is a derived tag. Link it with the base tag.
+	 */
+	tag->dt_parent = base;
+	tag->dt_chain = base->dt_child;
+	base->dt_child = tag;
+	*tag_p = tag;
+	return (0);
+}

Modified: projects/altix2/sys/sys/busdma.h
==============================================================================
--- projects/altix2/sys/sys/busdma.h	Sun May  6 20:26:28 2012	(r235104)
+++ projects/altix2/sys/sys/busdma.h	Sun May  6 20:37:02 2012	(r235105)
@@ -49,7 +49,25 @@ typedef struct busdma_tag *busdma_tag_t;
  *	tag_p		address in which to return the newly created tag.
  */
 int busdma_tag_create(device_t dev, bus_addr_t maxaddr, bus_addr_t align,
-    bus_addr_t bndry, bus_addr_t maxsz, u_int nsegs, bus_size_t maxsegsz,
+    bus_addr_t bndry, bus_size_t maxsz, u_int nsegs, bus_size_t maxsegsz,
+    u_int flags, busdma_tag_t *tag_p);
+
+/*
+ * busdma_tag_derive
+ * returns:		errno value
+ * arguments:
+ *	tag		The root tag that is to be derived from.
+ *	maxaddr		largest address that can be handled by the device.
+ *	align		alignment requirements of the DMA segments.
+ *	bndry		address boundary constraints for DMA.
+ *	maxsz		maximum total DMA size allowed.
+ *	nsegs		maximum number of DMA segments allowed.
+ *	maxsegsz	maximum size of a single DMA segment.
+ *	flags		flags that control the behaviour of the operation.
+ *	tag_p		address in which to return the newly created tag.
+ */
+int busdma_tag_derive(busdma_tag_t tag, bus_addr_t maxaddr, bus_addr_t align,
+    bus_addr_t bndry, bus_size_t maxsz, u_int nsegs, bus_size_t maxsegsz,
     u_int flags, busdma_tag_t *tag_p);
 
 #endif /* _SYS_BUSDMA_H_ */