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Question about virt_to_page
Hi,
I have a question about the virt_to_page function
2.6.5.
My development Linux system has 512 MB memory.
Through kernel command line (mem=448M), the kernel is
using only 448 MB (setting aside 64 MB). I have a
driver that uses the upper 64 MB.
I get a virtual address of the 64M region as follows:
cpuAddr = ioremap(0x1c000000, 64MB);
Question: Am I getting a continuous 64MB virtual
address space.
Having a virtual addres within the 64 MB meomry (lets
call it newAddr), I can find it's page/offset as
follows:
page = virt_to_page(newAddr); - (1)
page_ofset = newAddr & (~PAGE_MASK); - (1)
I perfrom the above calucation on random virtual
address's withing the 64 MB range. Once in a while, I
get page == 0. Can someone help me understand why?
Thank you,
Aha.
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