Re: [PATCH v3 7/7] drm/i915: fixup the initial fb base on DGFX

|This seems more natural to me than the previous version. Acked-by: Nirmoy Das nirmoy.das@linux.intel.com |

Nirmoy

On 14/03/2022 12:28, Matthew Auld wrote:

On integrated it looks like the GGTT base should always 1:1 maps to somewhere within DSM. On discrete the base seems to be pre-programmed with a normal lmem address, and is not 1:1 mapped with the base address. On such devices probe the lmem address directly from the PTE.

v2(Ville):

• The base is actually the pre-programmed GGTT address, which is then meant to 1:1 map to somewhere inside dsm. In the case of dgpu the base looks to just be some offset within lmem, but this also happens to be the exact dsm start, on dg1. Therefore we should only need to fudge the physical address, before allocating from stolen.
• Bail if it's not located in dsm.

v3:

• Scratch that. There doesn't seem to be any relationship with the base and PTE address, on at least DG1. Let's instead just grab the lmem address from the PTE itself.

Signed-off-by: Matthew Auldmatthew.auld@intel.com Cc: Thomas Hellströmthomas.hellstrom@linux.intel.com Cc: Ville Syrjäläville.syrjala@linux.intel.com Cc: Nirmoy Dasnirmoy.das@linux.intel.com

---

.../drm/i915/display/intel_plane_initial.c | 50 ++++++++++++++++--- 1 file changed, 44 insertions(+), 6 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..7979929bb632 100644 --- a/drivers/gpu/drm/i915/display/intel_plane_initial.c +++ b/drivers/gpu/drm/i915/display/intel_plane_initial.c @@ -47,17 +47,55 @@ static struct i915_vma * initial_plane_vma(struct drm_i915_private *i915, struct intel_initial_plane_config *plane_config) {

• struct intel_memory_region *mem = i915->mm.stolen_region;

• struct intel_memory_region *mem; struct drm_i915_gem_object *obj; struct i915_vma *vma;
• resource_size_t phys_base; u32 base, size; u64 pinctl;

• if (!mem || plane_config->size == 0)

• if (plane_config->size == 0)

• return NULL;
  

• base = round_down(plane_config->base, I915_GTT_MIN_ALIGNMENT);
• if (IS_DGFX(i915)) {

• gen8_pte_t __iomem *gte = to_gt(i915)->ggtt->gsm;
  

• gen8_pte_t pte;
  

• gte += base / I915_GTT_PAGE_SIZE;
  

• pte = ioread64(gte);
  

• if (!(pte & GEN12_GGTT_PTE_LM)) {
  

• 	drm_err(&i915->drm,
  

• 		"Initial plane programming missing PTE_LM bit\n");
  

• 	return NULL;
  

• }
  

• phys_base = pte & I915_GTT_PAGE_MASK;
  

• mem = i915->mm.regions[INTEL_REGION_LMEM];
  

• /*
  

•  * We don't currently expect this to ever be placed in the
  

•  * stolen portion.
  

•  */
  

• if (phys_base >= resource_size(&mem->region)) {
  

• 	drm_err(&i915->drm,
  

• 		"Initial plane programming using invalid range, phys_base=%pa\n",
  

• 		&phys_base);
  

• 	return NULL;
  

• }
  

• drm_dbg(&i915->drm,
  

• 	"Using phys_base=%pa, based on initial plane programming\n",
  

• 	&phys_base);
  

• } else {

• phys_base = base;
  

• mem = i915->mm.stolen_region;
  

• }
• if (!mem) 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); size -= base;

@@ -68,11 +106,11 @@ initial_plane_vma(struct drm_i915_private *i915, * features. */ if (IS_ENABLED(CONFIG_FRAMEBUFFER_CONSOLE) &&

•    mem == i915->mm.stolen_region &&
   size * 2 > i915->stolen_usable_size)
  

  return NULL;

• obj = i915_gem_object_create_region_at(i915->mm.stolen_region,

• 			       base, size, 0);
  

• obj = i915_gem_object_create_region_at(mem, phys_base, size, 0); if (IS_ERR(obj)) return NULL;