Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5a8e9943 authored by Michel Thierry's avatar Michel Thierry Committed by Daniel Vetter
Browse files

drm/i915/gen8: Initialize page tables 



Similar to gen6, while setting up a page table, make all entries of the
pt point to the scratch page before mapping; this is to be safe in case
of out of bound access or proactive prefetch.

Systems without LLC require an explicit flush.

v2: Expanded commit text and fixed indentation (Mika)

Signed-off-by: default avatarMichel Thierry <michel.thierry@intel.com>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 9c57f070

drivers/gpu/drm/i915/i915_gem_gtt.c

+21 −1
Original line number Diff line number Diff line
@@ -332,6 +332,24 @@ static void unmap_and_free_pt(struct i915_page_table *pt, 
	kfree(pt);

}



static void gen8_initialize_pt(struct i915_address_space *vm,

				struct i915_page_table *pt)

{

	gen8_pte_t *pt_vaddr, scratch_pte;

	int i;



	pt_vaddr = kmap_atomic(pt->page);

	scratch_pte = gen8_pte_encode(vm->scratch.addr,

				      I915_CACHE_LLC, true);



	for (i = 0; i < GEN8_PTES; i++)

		pt_vaddr[i] = scratch_pte;



	if (!HAS_LLC(vm->dev))

		drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);

	kunmap_atomic(pt_vaddr);

}



static struct i915_page_table *alloc_pt_single(struct drm_device *dev)

{

	struct i915_page_table *pt;
@@ -429,7 +447,7 @@ static struct i915_page_directory *alloc_pd_single(void) 
	if (!pd)

		return ERR_PTR(-ENOMEM);



	pd->page = alloc_page(GFP_KERNEL | __GFP_ZERO);

	pd->page = alloc_page(GFP_KERNEL);

	if (!pd->page) {

		kfree(pd);

		return ERR_PTR(-ENOMEM);
@@ -719,6 +737,8 @@ static int gen8_ppgtt_setup_page_tables(struct i915_hw_ppgtt *ppgtt, 
	struct page *p = ptab->page;

	int ret;



	gen8_initialize_pt(&ppgtt->base, ptab);



	pt_addr = pci_map_page(ppgtt->base.dev->pdev,

			       p, 0, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);

	ret = pci_dma_mapping_error(ppgtt->base.dev->pdev, pt_addr);