The current DMA routines are driven by a call in main_loop_wait() after every
select.
This patch converts the DMA code to be driven by a constantly rescheduled
bottom half. The advantage of using a scheduled bottom half is that we can
stop scheduling the bottom half when there no DMA channels are runnable. This
means we can potentially detect this case and sleep longer in the main loop.
The only two architectures implementing DMA_run() are cris and i386. For cris,
I converted it to a simple repeating bottom half. I've only compile tested
this as cris does not seem to work on a 64-bit host. It should be functionally
identical to the previous implementation so I expect it to work.
For x86, I've made sure to only fire the DMA bottom half if there is a DMA
channel that is runnable. The effect of this is that unless you're using sb16
or a floppy disk, the DMA bottom half never fires.
You probably should test this malc. My own benchmarks actually show slight
improvement by it's possible the change in timing could affect your demos.
Since v1, I've changed the code to use a BH instead of a timer. cris at least
seems to depend on faster than 10ms polling.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5573 c046a42c-6fe2-441c-8c8c-71466251a162
For outgoing DMA channels, keep processing descriptors until hitting end
of list.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5553 c046a42c-6fe2-441c-8c8c-71466251a162
* Correct numeric value for the RST state.
* Add emulation for reseting a DMA channel.
* Add a few sanity checks.
* Make it compile with debug enabled.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5147 c046a42c-6fe2-441c-8c8c-71466251a162
* When hitting EOL (end of list) at the data descriptor level, the DMA should mark the current context-descriptor as disabled and perform a context-store so software can see whats goin on.
* Context loads update RW_SAVED_DATA_BUF, data loads dont. This fixes an issue with ethernet bootstrapping.
* Reorder the logic for processing out channels to be more like the one for input channels.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4723 c046a42c-6fe2-441c-8c8c-71466251a162
* Move DMA_run into the dma controller to allow for multiple ETRAX/CRIS machines.
* Support both ELF and kimage kernel images.
* Correct emulation of the DMA RW_DATA register.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4678 c046a42c-6fe2-441c-8c8c-71466251a162
