Question about ioremap and io_remap_page_range

[舒国强 <guoqiang@intec.iscas.ac.cn>]

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 Here is some rather basic questions I want ask ,any reply or comment please
 CC to my emailbox,thank you very much.
 
 When I work with kernel 2.4.2 in Intel X86 , I use 
		
     VIRT_ADDR = ioremap(BUS_ADDR); to map a section of PCI memory, and
     X_ADDR = virt_to_phys(VIRT_ADDR);

  I think in x86 platform X_ADDR should equel with BUS_ADDR, but it turns to be
 NOT, can you explain ?

  In X86 platform ,Can I use return value of ioremap() as a memory pointer?


  I use io_remap_page_range(BUS_ADDR,,) in mmap() function,but the result is 
 that the memory I map is READ ONLY from user space,when I try to write to it,
 a "do_sw_pg. bogus page(XXXXXXXX)" appears. Can you explain to me?


  I know these questions are childish,but I need the answer urgently,thanks!


 George Shu
 

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