[PATCH 3/4] drm/i915/gem: Use set_pte_at() for assigning the vmapped PTE

[Chris Wilson]

Use set_pte_at() to assign the PTE pointer returned by alloc_vm_area(),
rather than a direct assignment.

Fixes: 6056e50033d9 ("drm/i915/gem: Support discontiguous lmem object maps")
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.a...@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_pages.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c 
b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 0fee67f34d74..6838cf9bdae6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -286,23 +286,34 @@ static void *i915_gem_object_map(struct 
drm_i915_gem_object *obj,
        }
 
        if (i915_gem_object_has_struct_page(obj)) {
+               unsigned long addr = (unsigned long)area->addr;
                struct sgt_iter iter;
                struct page *page;
                pte_t **ptes = mem;
 
-               for_each_sgt_page(page, iter, sgt)
-                       **ptes++ = mk_pte(page, pgprot);
+               for_each_sgt_page(page, iter, sgt) {
+                       set_pte_at(&init_mm, addr, *ptes, mk_pte(page, pgprot));
+                       addr += PAGE_SIZE;
+                       ptes++;
+               }
+               GEM_BUG_ON(addr != (unsigned long)area->addr + obj->base.size);
        } else {
+               unsigned long addr = (unsigned long)area->addr;
                resource_size_t iomap;
                struct sgt_iter iter;
                pte_t **ptes = mem;
-               dma_addr_t addr;
+               dma_addr_t offset;
 
                iomap = obj->mm.region->iomap.base;
                iomap -= obj->mm.region->region.start;
 
-               for_each_sgt_daddr(addr, iter, sgt)
-                       **ptes++ = iomap_pte(iomap, addr, pgprot);
+               for_each_sgt_daddr(offset, iter, sgt) {
+                       set_pte_at(&init_mm, addr, *ptes,
+                                  iomap_pte(iomap, offset, pgprot));
+                       addr += PAGE_SIZE;
+                       ptes++;
+               }
+               GEM_BUG_ON(addr != (unsigned long)area->addr + obj->base.size);
        }
        flush_vm_area(area);
 
-- 
2.20.1