Process VM Addr to Kernel VM Addr at Interrupt Time.

Greg Johnson (gjohnson@research.canon.com.au)
Wed, 28 Apr 1999 15:10:56 +1000 (EST)


Hi,

I have the following problem. An application talks directly to a
peripheral card. The application give the peripheral device an address
within the applications address space. Some time later, the peripheral
device generates and interrupt and the interrupt service routine reads
back the address given to the peripheral device earlier. The ISR
now needs to access the data at the memory location read back, but
it is in the memory space of the original application. The ISR
knows the process ID of the applicaiton in question, but since it
is not executing with the context of that application, how can it
convert the address in the applications address space, to its
own virtual address space?

Any advice, pointers etc appreciated.

Greg.

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