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, 16 insertions, 0 deletions

diff --git a/sys/dev/ips/ips.c b/sys/dev/ips/ips.c
index bd329d6..98a09d3 100644
--- a/sys/dev/ips/ips.c
+++ b/sys/dev/ips/ips.c
@@ -337,6 +337,8 @@ int ips_adapter_init(ips_softc_t *sc)
 				/* maxsegsize*/	IPS_COMMAND_LEN + 
 						    IPS_MAX_SG_LEN,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&sc->command_dmatag) != 0) {
                 device_printf(sc->dev, "can't alloc command dma tag\n");
 		goto error;
@@ -352,6 +354,8 @@ int ips_adapter_init(ips_softc_t *sc)
 				/* numsegs   */	IPS_MAX_SG_ELEMENTS,
 				/* maxsegsize*/	IPS_MAX_IOBUF_SIZE,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&sc->sg_dmatag) != 0) {
 		device_printf(sc->dev, "can't alloc SG dma tag\n");
 		goto error;
@@ -546,6 +550,8 @@ static int ips_copperhead_queue_init(ips_softc_t *sc)
 				/* numsegs   */	1,
 				/* maxsegsize*/	sizeof(ips_copper_queue_t),
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&dmatag) != 0) {
                 device_printf(sc->dev, "can't alloc dma tag for statue queue\n");
 		error = ENOMEM;
diff --git a/sys/dev/ips/ips_commands.c b/sys/dev/ips/ips_commands.c
index bcdb925..c83de4c 100644
--- a/sys/dev/ips/ips_commands.c
+++ b/sys/dev/ips/ips_commands.c
@@ -224,6 +224,8 @@ static int ips_send_adapter_info_cmd(ips_command_t *command)
 				/* numsegs   */	1,
 				/* maxsegsize*/	IPS_ADAPTER_INFO_LEN,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&command->data_dmatag) != 0) {
                 printf("ips: can't alloc dma tag for adapter status\n");
 		error = ENOMEM;
@@ -329,6 +331,8 @@ static int ips_send_drive_info_cmd(ips_command_t *command)
 				/* numsegs   */	1,
 				/* maxsegsize*/	IPS_DRIVE_INFO_LEN,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&command->data_dmatag) != 0) {
                 printf("ips: can't alloc dma tag for drive status\n");
 		error = ENOMEM;
@@ -497,6 +501,8 @@ static int ips_read_nvram(ips_command_t *command){
 				/* numsegs   */	1,
 				/* maxsegsize*/	IPS_NVRAM_PAGE_SIZE,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&command->data_dmatag) != 0) {
                 printf("ips: can't alloc dma tag for nvram\n");
 		error = ENOMEM;
diff --git a/sys/dev/ips/ips_ioctl.c b/sys/dev/ips/ips_ioctl.c
index 9c31dfc..4788ffc 100644
--- a/sys/dev/ips/ips_ioctl.c
+++ b/sys/dev/ips/ips_ioctl.c
@@ -98,6 +98,8 @@ static int ips_ioctl_cmd(ips_softc_t *sc, ips_ioctl_t *ioctl_cmd, ips_user_reque
 			/* numsegs   */	1,
 			/* maxsegsize*/	ioctl_cmd->datasize,
 			/* flags     */	0,
+			/* lockfunc  */ busdma_lock_mutex,
+			/* lockarg   */ &Giant,
 			&ioctl_cmd->dmatag) != 0) {
 		return ENOMEM;
         }
diff --git a/sys/dev/ips/ips_pci.c b/sys/dev/ips/ips_pci.c
index f998732..81fa0e6 100644
--- a/sys/dev/ips/ips_pci.c
+++ b/sys/dev/ips/ips_pci.c
@@ -128,6 +128,8 @@ static int ips_pci_attach(device_t dev)
 				/* numsegs   */	IPS_MAX_SG_ELEMENTS,
 				/* maxsegsize*/	BUS_SPACE_MAXSIZE_32BIT,
 				/* flags     */	0,
+				/* lockfunc  */ busdma_lock_mutex,
+				/* lockarg   */ &Giant,
 				&sc->adapter_dmatag) != 0) {
                 printf("IPS can't alloc dma tag\n");
                 goto error;