VOID HwVidBankedMemoryCallback(
| ULONG ReadBank, | |
| ULONG WriteBank, | |
| PVOID Context | |
| ); |
Every video miniport driver must have an HwVidBankedMemoryCallback function if it calls VideoPortMapBankedMemory to map a frame buffer that must be mapped in multiple Banks. HwVidBankedMemoryCallback is called by the Memory Manager whenever a location in the frame buffer referenced by a display driver requires the miniport driver to update the Bank Index Register in order to access that location.
Parameters
ReadBank
The index of the bank that has been referenced by the display driver in a read request.
WriteBank
The index of the bank that has been referenced by the display driver in a write request.
Context
Points to the context passed by the miniport driver in its VideoPortMapBankedMemory request.
Return Value
HwVidBankedMemoryCallback updates the Bank Index Register but does not return any status.
Comments
The Memory Manager calls this function at IRQL APC_LEVEL. No HwVidBankedMemoryCallback function can be pageable. If calling this function causes a page fault, the system will hang.
This function must execute quickly; therefore, the function must only update the Bank Index Register and return.
See Also
VideoPortMapBankedMemory, IOCTL_VIDEO_MAP_VIDEO_MEMORY, IOCTL_VIDEO_UNMAP_MEMORY, IOCTL_VIDEO_SHARE_VIDEO_MEMORY, IOCTL_VIDEO_UNSHARE_VIDEO_MEMORY.