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

1 files changed, 4 insertions, 4 deletions

diff --git a/sys/dev/mpt/mpt_pci.c b/sys/dev/mpt/mpt_pci.c
index 1351354..09c2847 100644
--- a/sys/dev/mpt/mpt_pci.c
+++ b/sys/dev/mpt/mpt_pci.c
@@ -502,7 +502,7 @@ mpt_dma_mem_alloc(mpt_softc_t *mpt)
 	if (bus_dma_tag_create(NULL, PAGE_SIZE, 0, BUS_SPACE_MAXADDR_32BIT,
 	    BUS_SPACE_MAXADDR, NULL, NULL, BUS_SPACE_MAXSIZE_32BIT,
 	    BUS_SPACE_MAXSIZE_32BIT, BUS_SPACE_UNRESTRICTED, 0,
-	    &mpt->parent_dmat) != 0) {
+	    busdma_lock_mutex, &Giant, &mpt->parent_dmat) != 0) {
 		device_printf(dev, "cannot create parent dma tag\n");
 		return (1);
 	}
@@ -511,7 +511,7 @@ mpt_dma_mem_alloc(mpt_softc_t *mpt)
 	if (bus_dma_tag_create(mpt->parent_dmat, PAGE_SIZE,
 	    0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 	    NULL, NULL, PAGE_SIZE, 1, BUS_SPACE_MAXSIZE_32BIT, 0,
-	    &mpt->reply_dmat) != 0) {
+	    busdma_lock_mutex, &Giant, &mpt->reply_dmat) != 0) {
 		device_printf(dev, "cannot create a dma tag for replies\n");
 		return (1);
 	}
@@ -542,7 +542,7 @@ mpt_dma_mem_alloc(mpt_softc_t *mpt)
 	if (bus_dma_tag_create(mpt->parent_dmat, PAGE_SIZE,
 	    0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 	    NULL, NULL, MAXBSIZE, MPT_SGL_MAX, BUS_SPACE_MAXSIZE_32BIT, 0,
-	    &mpt->buffer_dmat) != 0) {
+	    busdma_lock_mutex, &Giant, &mpt->buffer_dmat) != 0) {
 		device_printf(dev,
 		    "cannot create a dma tag for data buffers\n");
 		return (1);
@@ -552,7 +552,7 @@ mpt_dma_mem_alloc(mpt_softc_t *mpt)
 	if (bus_dma_tag_create(mpt->parent_dmat, PAGE_SIZE,
 	    0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 	    NULL, NULL, MPT_REQ_MEM_SIZE(mpt), 1, BUS_SPACE_MAXSIZE_32BIT, 0,
-	    &mpt->request_dmat) != 0) {
+	    busdma_lock_mutex, &Giant, &mpt->request_dmat) != 0) {
 		device_printf(dev, "cannot create a dma tag for requests\n");
 		return (1);
 	}