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, 12 insertions, 9 deletions

diff --git a/sys/dev/aac/aac.c b/sys/dev/aac/aac.c
index 21935a8..72fee9c 100644
--- a/sys/dev/aac/aac.c
+++ b/sys/dev/aac/aac.c
@@ -233,8 +233,15 @@ aac_attach(struct aac_softc *sc)
 	if ((error = aac_check_firmware(sc)) != 0)
 		return(error);
 
-	/* Init the sync fib lock */
+	/*
+	 * Initialize locks
+	 */
 	AAC_LOCK_INIT(&sc->aac_sync_lock, "AAC sync FIB lock");
+	AAC_LOCK_INIT(&sc->aac_aifq_lock, "AAC AIF lock");
+	AAC_LOCK_INIT(&sc->aac_io_lock, "AAC I/O lock");
+	AAC_LOCK_INIT(&sc->aac_container_lock, "AAC container lock");
+	TAILQ_INIT(&sc->aac_container_tqh);
+
 
 	/*
 	 * Initialise the adapter.
@@ -248,14 +255,6 @@ aac_attach(struct aac_softc *sc)
 	aac_describe_controller(sc);
 
 	/*
-	 * Initialize locks
-	 */
-	AAC_LOCK_INIT(&sc->aac_aifq_lock, "AAC AIF lock");
-	TAILQ_INIT(&sc->aac_container_tqh);
-	AAC_LOCK_INIT(&sc->aac_container_lock, "AAC container lock");
-	AAC_LOCK_INIT(&sc->aac_io_lock, "AAC I/O lock");
-
-	/*
 	 * Register to probe our containers later.
 	 */
 	sc->aac_ich.ich_func = aac_startup;
@@ -1450,6 +1449,8 @@ aac_init(struct aac_softc *sc)
 			       AAC_MAXSGENTRIES,	/* nsegments */
 			       MAXBSIZE,		/* maxsegsize */
 			       BUS_DMA_ALLOCNOW,	/* flags */
+			       busdma_lock_mutex,	/* lockfunc */
+			       &sc->aac_io_lock,	/* lockfuncarg */
 			       &sc->aac_buffer_dmat)) {
 		device_printf(sc->aac_dev, "can't allocate buffer DMA tag\n");
 		goto out;
@@ -1471,6 +1472,7 @@ aac_init(struct aac_softc *sc)
 			       AAC_FIB_COUNT *
 			       sizeof(struct aac_fib),	/* maxsegsize */
 			       BUS_DMA_ALLOCNOW,	/* flags */
+			       NULL, NULL,		/* No locking needed */
 			       &sc->aac_fib_dmat)) {
 		device_printf(sc->aac_dev, "can't allocate FIB DMA tag\n");;
 		goto out;
@@ -1490,6 +1492,7 @@ aac_init(struct aac_softc *sc)
 			       1,			/* nsegments */
 			       BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
 			       BUS_DMA_ALLOCNOW,	/* flags */
+			       NULL, NULL,		/* No locking needed */
 			       &sc->aac_common_dmat)) {
 		device_printf(sc->aac_dev,
 			      "can't allocate common structure DMA tag\n");