drm/xe: Return 2MB page size for compact 64k PTEs

Compact 64k PTEs are only intended to be used within a single VMA which
covers the entire 2MB range of the compact 64k PTEs. Add
XE_VMA_PTE_COMPACT VMA flag to indicate compact 64k PTEs are used and
update xe_vma_max_pte_size to return at least 2MB if set.

v2: Include missing changes

Fixes: 8f33b4f0 ("drm/xe: Avoid doing rebinds")
Fixes: c47794bd ("drm/xe: Set max pte size when skipping rebinds")
Reported-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/758Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240219211942.3633795-4-matthew.brost@intel.com

drivers/gpu/drm/xe/xe_pt.c

@@ -547,13 +547,16 @@ xe_pt_stage_bind_entry(struct xe_ptw *parent, pgoff_t offset,
 		*child = &xe_child->base;
 
 		/*
-		 * Prefer the compact pagetable layout for L0 if possible.
+		 * Prefer the compact pagetable layout for L0 if possible. Only
+		 * possible if VMA covers entire 2MB region as compact 64k and
+		 * 4k pages cannot be mixed within a 2MB region.
 		 * TODO: Suballocate the pt bo to avoid wasting a lot of
 		 * memory.
 		 */
 		if (GRAPHICS_VERx100(tile_to_xe(xe_walk->tile)) >= 1250 && level == 1 &&
 		    covers && xe_pt_scan_64K(addr, next, xe_walk)) {
 			walk->shifts = xe_compact_pt_shifts;
+			xe_walk->vma->gpuva.flags |= XE_VMA_PTE_COMPACT;
 			flags |= XE_PDE_64K;
 			xe_child->is_compact = true;
 		}

drivers/gpu/drm/xe/xe_vm.c

@@ -2190,7 +2190,7 @@ static u64 xe_vma_max_pte_size(struct xe_vma *vma)
 {
 	if (vma->gpuva.flags & XE_VMA_PTE_1G)
 		return SZ_1G;
-	else if (vma->gpuva.flags & XE_VMA_PTE_2M)
+	else if (vma->gpuva.flags & (XE_VMA_PTE_2M | XE_VMA_PTE_COMPACT))
 		return SZ_2M;
 	else if (vma->gpuva.flags & XE_VMA_PTE_64K)
 		return SZ_64K;

drivers/gpu/drm/xe/xe_vm_types.h

@@ -30,6 +30,7 @@ struct xe_vm;
 #define XE_VMA_PTE_2M		(DRM_GPUVA_USERBITS << 6)
 #define XE_VMA_PTE_1G		(DRM_GPUVA_USERBITS << 7)
 #define XE_VMA_PTE_64K		(DRM_GPUVA_USERBITS << 8)
+#define XE_VMA_PTE_COMPACT	(DRM_GPUVA_USERBITS << 9)
 
 /** struct xe_userptr - User pointer */
 struct xe_userptr {