mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-20 03:04:01 +08:00
803c874abe
The LSI MEGARAID SAS HBA suffers from the problem where it can do 64-bit DMA to streaming buffers but not to consistent buffers. In other words, 64-bit DMA is used for disk data transfers and 32-bit DMA must be used for control message transfers. According to LSI, the firmware is not fully functional yet. This change implements a kind of hybrid dma_ops to support this. Note that on most other platforms, the 64-bit DMA addressing space is the same as the 32-bit DMA space and they overlap the physical memory space. No special arrangement is needed to support this kind of mixed DMA capability. On TILE-Gx, the 64-bit DMA space is completely separate from the 32-bit DMA space. Due to the use of the IOMMU, the 64-bit DMA space doesn't overlap the physical memory space. On the other hand, the 32-bit DMA space overlaps the physical memory space under 4GB. The separate address spaces make it necessary to have separate dma_ops. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> |
||
|---|---|---|
| .. | ||
| configs | ||
| gxio | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| mm | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||