Howto allocate non-cacheable memory

[Muneeswaran P - TLS, Chennai]

Hi,

How to allocate non-cacheable kernel memory ?

Pls help me.


	I am writing device driver (kernel 2.6 ) for PCI-X card.

	Pls clarify the following doubts:
	1. DPRAM is memory mapped to PCI-X card.
	2. I have to transfer data from main memory to DPRAM using bus
master concept and vice-versa.
	3. How to make this memory area as non-cacheable one ? 
	4. Whether DMA mapping (pci_map_single() call ) should be done for
both DPRAM and main memory ?
	   4.a) I will get the physical address of DPRAM memory (memory
mapped to PCI-X card) from BAR-0 register. Can i use this physical addres
directly for data transer using bus master (without pci_map_single() call.)
?
	   4.b)  How to make main memory area as non-cacheable one ?


Regards,
Munees.
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