On Mon, Mar 07, 2022 at 10:32:36AM +0000, Matthew Auld wrote:
On 04/03/2022 19:33, Ville Syrjälä wrote:
On Fri, Mar 04, 2022 at 05:23:32PM +0000, Matthew Auld wrote:
The offset we get looks to be the exact start of DSM, but the inital_plane_vma expects the address to be relative.
Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com
.../drm/i915/display/intel_plane_initial.c | 22 +++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_plane_initial.c b/drivers/gpu/drm/i915/display/intel_plane_initial.c index f797fcef18fc..b39d3a8dfe45 100644 --- a/drivers/gpu/drm/i915/display/intel_plane_initial.c +++ b/drivers/gpu/drm/i915/display/intel_plane_initial.c @@ -56,10 +56,24 @@ initial_plane_vma(struct drm_i915_private *i915, if (!mem || plane_config->size == 0) return NULL;
- base = round_down(plane_config->base,
I915_GTT_MIN_ALIGNMENT);- size = round_up(plane_config->base + plane_config->size,
mem->min_page_size);
- base = plane_config->base;
- if (IS_DGFX(i915)) {
/** On discrete the base address should be somewhere in LMEM, but* depending on the size of LMEM the base address might* intersect with the start of DSM, like on DG1, in which case* we need the relative address. In such cases we might also* need to choose between inital fb vs fbc, if space is limited.** On future discrete HW, like DG2, we should be able to just* allocate directly from LMEM, due to larger LMEM size.*/if (base >= i915->dsm.start)base -= i915->dsm.start;Subsequent code expects the object to actually be inside stolen. If that is not the case we should just give up.
Thanks for taking a look at this. Is that subsequent code outside initial_plane_vma()? In the next patch this is now using LMEM directly for dg2. Would that blow up somewhere else?
It uses i915_gem_object_create_stolen_for_preallocated() which assumes the stuff is inside stolen.
The fact that we fail to confirm any of that on integrated parts has always bugged me, but not enough to actually do anything about it. Such a check would be somewhat more involved since we'd have to look at the PTEs. But on discrete sounds like we can get away with a trivial check.
Which PTEs?
The PTEs the plane is actually using. We have no idea where they actually point to and just assume they represent a 1:1 mapping of stolen.
I suppose with lmem we'll just start assuming a 1:1 mapping of the whole lmem rather than just stolen.