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, 7 insertions, 4 deletions

diff --git a/sys/dev/hatm/if_hatm.c b/sys/dev/hatm/if_hatm.c
index 48c45b8..30835b5 100644
--- a/sys/dev/hatm/if_hatm.c
+++ b/sys/dev/hatm/if_hatm.c
@@ -214,7 +214,8 @@ hatm_alloc_dmamem(struct hatm_softc *sc, const char *what, struct dmamem *mem)
 	error = bus_dma_tag_create(sc->parent_tag, mem->align, 0,
 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR,
 	    NULL, NULL, mem->size, 1,
-	    BUS_SPACE_MAXSIZE_32BIT, BUS_DMA_ALLOCNOW, &mem->tag);
+	    BUS_SPACE_MAXSIZE_32BIT, BUS_DMA_ALLOCNOW,
+	    busdma_lock_mutex, &Giant, &mem->tag);
 	if (error) {
 		if_printf(&sc->ifatm.ifnet, "DMA tag create (%s)\n", what);
 		return (error);
@@ -1712,7 +1713,8 @@ hatm_attach(device_t dev)
 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR,
 	    NULL, NULL,
 	    BUS_SPACE_MAXSIZE_32BIT, 1,
-	    BUS_SPACE_MAXSIZE_32BIT, 0, &sc->parent_tag)) {
+	    BUS_SPACE_MAXSIZE_32BIT, 0,
+	    busdma_lock_mutex, &Giant, &sc->parent_tag)) {
 		device_printf(dev, "could not allocate DMA tag\n");
 		error = ENOMEM;
 		goto failed;
@@ -1722,7 +1724,8 @@ hatm_attach(device_t dev)
 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR,
 	    NULL, NULL,
 	    MBUF_ALLOC_SIZE, 1,
-	    MBUF_ALLOC_SIZE, 0, &sc->mbuf_tag)) {
+	    MBUF_ALLOC_SIZE, 0,
+	    busdma_lock_mutex, &Giant, &sc->mbuf_tag)) {
 		device_printf(dev, "could not allocate mbuf DMA tag\n");
 		error = ENOMEM;
 		goto failed;
@@ -1738,7 +1741,7 @@ hatm_attach(device_t dev)
 	if (bus_dma_tag_create(NULL, 1, 0,
 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
 	    HE_MAX_PDU, 3 * HE_CONFIG_MAX_TPD_PER_PACKET, HE_MAX_PDU, 0,
-	    &sc->tx_tag)) {
+	    busdma_lock_mutex, &Giant, &sc->tx_tag)) {
 		device_printf(dev, "could not allocate TX tag\n");
 		error = ENOMEM;
 		goto failed;