On Fri, May 27, 2011 at 10:54 PM, Mulyadi Santosa <mulyadi.santosa@gmail.com
wrote:
Hi...
On Fri, May 27, 2011 at 17:49, sandeep kumar <coolsandyforyou@gmail.com> wrote:
Now the question is can we memory map a one device resource(say some iomemory) to two different memory locations? the other way of seeing at this question is, Will ioremap() gives different 'virtual addresses' when called multiple times?
I agree with Daniel, but I suggest you to think about it: in reading operation, maybe it's ok, no concurrency issues need to be taken care...but how about writing? unless we're sure they are atomically or uninterruptible, i see a chance that race condition might happen here.
Actually it's similar when you map a file into two different VMA and write into it, correct?
Don't you think it would also be reducing the memory map space in RAM which is a critical resource and many other drivers would be denied the mapping of there IO resources? -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com
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