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, 3 insertions, 2 deletions

diff --git a/sys/dev/ct/ct_isa.c b/sys/dev/ct/ct_isa.c
index c4555a9..d7b2be5 100644
--- a/sys/dev/ct/ct_isa.c
+++ b/sys/dev/ct/ct_isa.c
@@ -240,7 +240,8 @@ ct_isa_attach(device_t dev)
 			       BUS_SPACE_MAXADDR_24BIT, BUS_SPACE_MAXADDR,
 			       NULL, NULL, MAXBSIZE, 1,
 			       BUS_SPACE_MAXSIZE_32BIT,
-			       BUS_DMA_ALLOCNOW, &ct->sc_dmat) != 0) {
+			       BUS_DMA_ALLOCNOW, NULL, NULL,
+			       &ct->sc_dmat) != 0) {
 		device_printf(dev, "can't set up ISA DMA map\n");
 		ct_space_unmap(dev, ct);
 		return ENXIO;
@@ -254,7 +255,7 @@ ct_isa_attach(device_t dev)
 	}
 
 	bus_dmamap_load(ct->sc_dmat, ct->sc_dmamapt, vaddr, MAXBSIZE,
-			ct_dmamap, &addr, 0);
+			ct_dmamap, &addr, BUS_DMA_NOWAIT);
 
 	/* setup machdep softc */
 	bs->sc_hw = hw;