diff options
Diffstat (limited to 'share/man')
-rw-r--r-- | share/man/man9/bus_dma.9 | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/share/man/man9/bus_dma.9 b/share/man/man9/bus_dma.9 index b081cf4..b2ab769 100644 --- a/share/man/man9/bus_dma.9 +++ b/share/man/man9/bus_dma.9 @@ -283,7 +283,7 @@ Client specified lock/mutex manipulation method. This will be called from within busdma whenever a client lock needs to be manipulated. In its current form, the function will be called immediately before -the callback for a dma load operation that has been deferred with +the callback for a DMA load operation that has been deferred with .Dv BUS_DMA_LOCK and immediately after with .Dv BUS_DMA_UNLOCK . @@ -364,17 +364,26 @@ indicates that there are no boundary restrictions. Bounds of the window of bus address space that .Em cannot be directly accessed by the device. -The window contains all addresses greater than lowaddr and -less than or equal to highaddr. -For example, a device incapable of DMA above 4GB, would specify -a highaddr of +The window contains all addresses greater than +.Fa lowaddr +and less than or equal to +.Fa highaddr . +For example, a device incapable of DMA above 4GB, would specify a +.Fa highaddr +of .Dv BUS_SPACE_MAXADDR -and a lowaddr of +and a +.Fa lowaddr +of .Dv BUS_SPACE_MAXADDR_32BIT . -Similarly a device that can only dma to addresses bellow 16MB would -specify a highaddr of +Similarly a device that can only perform DMA to addresses below +16MB would specify a +.Fa highaddr +of .Dv BUS_SPACE_MAXADDR -and a lowaddr of +and a +.Fa lowaddr +of .Dv BUS_SPACE_MAXADDR_24BIT . Some implementations requires that some region of device visible address space, overlapping available host memory, be outside the |