Re: 64 bit memory access
From: Dan Malek <hidden>
Date: 2000-12-29 18:09:56
Tim Montgomery wrote:
I need to: 1.) figure out a way to perform a 64bit write via other means
Cache the location. When you access the space the processor will do a 64-bit read. You will have to run in copyback mode then when done updating the location push the cache line to the device.
Any suggestions/insight would be appreciated.
Using 64-bit only I/O, and FP registers on a 32-bit processor is an interesting hardware/software hack, but not a very good system design. I guess we could write some kernel 64-bit I/O functions that use an FP register. This would require disabling interrupts, enabling the FPU in the kernel, saving a register, doing the I/O, restoring the register, disabling the FPU, and enabling interrupts. Not very efficient when a proper 60x bus implementation that allowed sizing would have been really fast......... -- Dan ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/