The first one is a one liner fixing a stupid typo in the VM handling code and is only relevant if play with one of the VM defines.
The other two switches CIK to use the CPDMA instead of the SDMA for buffer moves, as it turned out the SDMA is still sometimes not 100% reliable.
* 'drm-fixes-3.15' of git://people.freedesktop.org/~deathsimple/linux:
drm/radeon: use the CP DMA on CIK
drm/radeon: sync page table updates
drm/radeon: fix vm buffer size estimation