[PATCH 4.10 81/81] drm/i915: A hotfix for making aliasing PPGTT work for GVT-g

Greg Kroah-Hartman
2017-04-06T08:52:28Z

From: Zhi Wang <zhi.a.wang@intel.com>

commit 3e52d71ede206df75b56208e7c7a277ef157bb71 upstream.

This patch makes PPGTT page table non-shrinkable when using aliasing PPGTT
mode. It's just a temporary solution for making GVT-g work.

Fixes: 2ce5179fe826 ("drm/i915/gtt: Free unused lower-level page tables")
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhiyuan Lv <zhiyuan.lv@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1486559013-25251-2-git-send-email-zhi.a.wang@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit e81ecb5e31db6c2a259d694738cf620d9fa70861)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/i915/i915_gem_gtt.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -735,9 +735,10 @@ static bool gen8_ppgtt_clear_pt(struct i
GEM_BUG_ON(pte_end > GEN8_PTES);

bitmap_clear(pt->used_ptes, pte, num_entries);
-
- if (bitmap_empty(pt->used_ptes, GEN8_PTES))
- return true;
+ if (USES_FULL_PPGTT(vm->i915)) {
+ if (bitmap_empty(pt->used_ptes, GEN8_PTES))
+ return true;
+ }

pt_vaddr = kmap_px(pt);