The functional HSA signal read was a hack left in the gpu-compute code.
In full system, this functional read is causing problems occasionally
with the translation not yet being in the page table. The error message
output by gem5 was a fatal message on the readBlob method in port proxy.
Changing this to a timing DMA fixes this problem.
This commit adds the various timing DMA functions to send and receive
response and clean up. A helper method "sendCompletionSignal" is added
to the GPUCommandProcessor because the indentation level was getting too
deep. This change applies only to FS mode. Code for SE mode is
equivalent to what it was before this commit.
Change-Id: I1bfcaa0a52731cdf9532a7fd0eb06ab2f0e09d48
57b3d2897c