hi,Jun Sun，
在 2001-09-19 12:39:00 you wrote：
>
>> >It is typically much easier to modify PCI device BARS so that they do
>> >coincide
>> >with the same physical address. You can control that by using the correct
>> >starting address for PCI MEM space in pci_auto.c resource assignment.
>> It seems a good way to solve the ioremap problem and X problem.But
>> virt_to_bus
>> & bus_to_virt problem remains?
>>
>
>What is the virt_to_bus() problem? Is the address beyond 512MB (phy addr)?
No,I mean problem caused different cpu & pci address space.from pci's view,
the main memory is at address 0x80000000-0x90000000 in p6032.But for cpu,
they are 0x0-0x10000000.So current virt_to_bus & bus_to_virt won't work.
>If PCI mem (BUS) address is identical to phy addr, you should not have problem
>unless the address is beyond 512MB.
yes:).When i solve the 8259,i will try to make them same.
>
>BTW, virt_to_bus()/bus_to_virt() are deprecicated. See
>Documentation/DMA-mapping.txt.
I think the "depreciated" is only for direct usage: they are used in
arch/mips/pci-dma.c to implement new interface pci_alloc_consistent.
And there are still many driver using them(grep tell me).Am i missing
something?
>
>Jun
Regards
Zhang Fuxin
fxzhang@ict.ac.cn
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