On Tue, Jul 28, 2015 at 04:16:03PM +0100, Dave Gordon wrote: > On 28/07/15 00:12, O'Rourke, Tom wrote: > >On Mon, Jul 27, 2015 at 03:41:31PM -0700, Yu Dai wrote: > >> > >>On 07/24/2015 03:31 PM, O'Rourke, Tom wrote: > >>>[TOR:] When I see "phase 1" I also look for "phase 2". > >>>A subject that better describes the change in this patch > >>>would help. > >>> > >>>On Thu, Jul 09, 2015 at 07:29:08PM +0100, Dave Gordon wrote: > >>>>From: Alex Dai <yu.dai@xxxxxxxxx> > >>>> > >>>>This adds the first of the data structures used to communicate with the > >>>>GuC (the pool of guc_context structures). > >>>> > >>>>We create a GuC-specific wrapper round the GEM object allocator as all > >>>>GEM objects shared with the GuC must be pinned into GGTT space at an > >>>>address that is NOT in the range [0..WOPCM_SIZE), as that range of GGTT > >>>>addresses is not accessible to the GuC (from the GuC's point of view, > >>>>it's permanently reserved for other objects such as the BootROM & SRAM). > >>>[TOR:] I would like a clarfication on the excluded range. > >>>The excluded range should be 0 to "size for guc within > >>>WOPCM area" and not 0 to "size of WOPCM area". > >> > >>Nope, GGTT range [0..WOPCM_SIZE) should be excluded from GuC usage. > >>BSpec clearly says, from 0 to WOPCM_TOP-1 is for BootROM, SRAM and > >>WOPCM. From WOPCM_TOP and above is GFX DRAM. Be note that, that GGTT > >>space is still available to any gfx obj as long as it is not > >>accessed by GuC (OK to pass through GuC). > >> > >[TOR:] Should we take a closer look at the pin offset bias > >for guc objects? GUC_WOPCM_SIZE_VALUE is not the full size > >of WOPCM area. > > I'm inclined to set the bias to GUC_WOPCM_TOP, and then define that > as the sum of GUC_WOPCM_OFFSET_VALUE and GUC_WOPCM_SIZE_VALUE. That > seems to be what the BSpec pages "WriteOnceProtectedContentMemory > (WOPCM) Management" and "WOPCM Memory Map" suggest, although I think > they're pretty unclear on the details :( > > Do you (both) agree this would be the right value? [TOR:] No, I do not think that is the right value. I think the excluded range should be [0 ... GUC_WOPCM_SIZE_VALUE) and that GUC_WOPCM_SIZE_VALUE should be used as the bias (as it is now) for objects used by GuC. The term "WOPCM_SIZE" is ambiguous since it could mean GUC_WOPCM_SIZE (as in 0xc050) or it could mean "size of WOPCM area" (as in 0x1082C0). It gets used both ways in the BSpec. > > [snip] [snip] _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
