drm/i915: Get context early in execbuf
We need to have the address space when reserving space for the objects. Since the address space and context are tied together, and reserve occurs before context switch (for good reason), we must lookup our context earlier in the process. This leaves some room for optimizations where we no longer need to use ctx_id in certain places. This will be addressed in a subsequent patch. Important tricky bit: Because slow relocations during execbuffer drop struct_mutex Perhaps it would be best to acquire the reference when we get the context, but I'll save that for another day (note I have written the patch before, and I found the changes required to be uglier than this). Note that since we currently access everything via context id, and not the data structure this is fine, though not desirable. The next change attempts to get the context only once via the context ID idr lookup, and as such, the following can happen: CTX-A is created, refcount = 1 CTX-A execbuf, mutex dropped close IOCTL called on CTX-A, refcount = 0 CTX-A resumes in execbuf. v2: Rebased on top of commit b6359918 Author: Mika Kuoppala <mika.kuoppala@linux.intel.com> Date: Wed Oct 30 15:44:16 2013 +0200 drm/i915: add i915_get_reset_stats_ioctl v3: Rebased on top of commit 25b3dfc8 Author: Mika Westerberg <mika.westerberg@linux.intel.com> Date: Tue Nov 12 11:57:30 2013 +0200 Author: Mika Kuoppala <mika.kuoppala@linux.intel.com> Date: Tue Nov 26 16:14:33 2013 +0200 drm/i915: check context reset stats before relocations Signed-off-by: NBen Widawsky <ben@bwidawsk.net> Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
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