Mega busdma API commit.

Add two new arguments to bus_dma_tag_create(): lockfunc and lockfuncarg.
Lockfunc allows a driver to provide a function for managing its locking
semantics while using busdma.  At the moment, this is used for the
asynchronous busdma_swi and callback mechanism.  Two lockfunc implementations
are provided: busdma_lock_mutex() performs standard mutex operations on the
mutex that is specified from lockfuncarg.  dftl_lock() is a panic
implementation and is defaulted to when NULL, NULL are passed to
bus_dma_tag_create().  The only time that NULL, NULL should ever be used is
when the driver ensures that bus_dmamap_load() will not be deferred.
Drivers that do not provide their own locking can pass
busdma_lock_mutex,&Giant args in order to preserve the former behaviour.

sparc64 and powerpc do not provide real busdma_swi functions, so this is
largely a noop on those platforms.  The busdma_swi on is64 is not properly
locked yet, so warnings will be emitted on this platform when busdma
callback deferrals happen.

If anyone gets panics or warnings from dflt_lock() being called, please
let me know right away.

Reviewed by:	tmm, gibbs

4 files changed, 17 insertions, 1 deletions

diff --git a/sys/dev/dpt/dpt_eisa.c b/sys/dev/dpt/dpt_eisa.c
index 1479403..9ad30c4 100644
--- a/sys/dev/dpt/dpt_eisa.c
+++ b/sys/dev/dpt/dpt_eisa.c
@@ -30,6 +30,8 @@
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/module.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
 #include <sys/bus.h>
 
 #include <machine/bus_pio.h>
@@ -128,7 +130,9 @@ dpt_eisa_attach (device_t dev)
 				/* maxsize   */	BUS_SPACE_MAXSIZE_32BIT,
 				/* nsegments */	~0,
 				/* maxsegsz  */	BUS_SPACE_MAXSIZE_32BIT,
-				/* flags     */0,
+				/* flags     */ 0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&dpt->parent_dmat) != 0) {
 		error = ENXIO;
 		goto bad;
diff --git a/sys/dev/dpt/dpt_isa.c b/sys/dev/dpt/dpt_isa.c
index 708bb69..183b9fb 100644
--- a/sys/dev/dpt/dpt_isa.c
+++ b/sys/dev/dpt/dpt_isa.c
@@ -189,6 +189,8 @@ dpt_isa_attach (device_t dev)
 				/* nsegments */	~0,
 				/* maxsegsz  */	BUS_SPACE_MAXSIZE_32BIT,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&dpt->parent_dmat) != 0) {
 		error = ENXIO;
 		goto bad;
diff --git a/sys/dev/dpt/dpt_pci.c b/sys/dev/dpt/dpt_pci.c
index 88e88da..4da3d80 100644
--- a/sys/dev/dpt/dpt_pci.c
+++ b/sys/dev/dpt/dpt_pci.c
@@ -33,6 +33,8 @@
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/module.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
 #include <sys/bus.h>
 
 #include <machine/bus_memio.h>
@@ -144,6 +146,8 @@ dpt_pci_attach (device_t dev)
 				/* nsegments */	~0,
 				/* maxsegsz  */	BUS_SPACE_MAXSIZE_32BIT,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&dpt->parent_dmat) != 0) {
 		dpt_free(dpt);
 		error = ENXIO;
diff --git a/sys/dev/dpt/dpt_scsi.c b/sys/dev/dpt/dpt_scsi.c
index 913578f..dc54d4b 100644
--- a/sys/dev/dpt/dpt_scsi.c
+++ b/sys/dev/dpt/dpt_scsi.c
@@ -1304,6 +1304,8 @@ dpt_init(struct dpt_softc *dpt)
 				/* nsegments	*/ 1,
 				/* maxsegsz	*/ BUS_SPACE_MAXSIZE_32BIT,
 				/* flags	*/ 0,
+				/* lockfunc	*/ busdma_lock_mutex,
+				/* lockarg	*/ &Giant,
 				&dpt->sg_dmat) != 0) {
 		goto error_exit;
         }
@@ -1431,6 +1433,8 @@ dpt_init(struct dpt_softc *dpt)
 				/* nsegments	*/ dpt->sgsize,
 				/* maxsegsz	*/ BUS_SPACE_MAXSIZE_32BIT,
 				/* flags	*/ BUS_DMA_ALLOCNOW,
+				/* lockfunc	*/ busdma_lock_mutex,
+				/* lockarg	*/ &Giant,
 				&dpt->buffer_dmat) != 0) {
 		printf("dpt: bus_dma_tag_create(...,dpt->buffer_dmat) failed\n");
 		goto error_exit;
@@ -1452,6 +1456,8 @@ dpt_init(struct dpt_softc *dpt)
 				/* nsegments	*/ 1,
 				/* maxsegsz	*/ BUS_SPACE_MAXSIZE_32BIT,
 				/* flags	*/ 0,
+				/* lockfunc	*/ busdma_lock_mutex,
+				/* lockarg	*/ &Giant,
 				&dpt->dccb_dmat) != 0) {
 		printf("dpt: bus_dma_tag_create(...,dpt->dccb_dmat) failed\n");
 		goto error_exit;