Hi there.
I have a few questions regarding the new DMA API.
1. dma_map_single finally calls virt_to_bus, which is simplified
to:
return (unsigned long)address - KERNELBASE + PCI_DRAM_OFFSET;
PCI_DRAM_OFFSET is defined to be pci_dram_offset.
Typically it is set be 0 for most arches without pci.
How could we overide it with a constant 0 so that we avoid the
memory access?
2. How soon in the init sequence could we call dma_alloc_consistent?
For example when setting up a serial console on 8xx I need memory
for the fifos, and I have to revert in using m8xx_hostalloc which
IMO should be already dead.
If we could arrange for consistent_alloc to be able to operate with
a fixed memory area until the memory initialization is complete
it would make my life much easier and we could finally kill
m8xx_hostalloc & friends.
3. The first argument is dma_* function is a struct device.
When working with network devices I must set this to NULL.
Granted this is no problem right now, but could this be
a problem in the future?
Regards
Pantelis
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