| Message ID | 1478006856-8313-1-git-send-email-mika.kuoppala@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On ti, 2016-11-01 at 15:27 +0200, Mika Kuoppala wrote: > Comparing pte index to a number of entries is wrong > when clearing a range of pte entries. Use end marker > of 'one past' to correctly point adequate number of > ptes to the scratch page. > > v2: assert early instead of warning late (Chris) > v3: removed consts (Joonas) > > Fixes: d209b9c3cd28 ("drm/i915/gtt: Split gen8_ppgtt_clear_pte_range") > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98282 > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > Cc: Michel Thierry <michel.thierry@intel.com> > Cc: Michał Winiarski <michal.winiarski@intel.com> > Reported-by: Mike Lothian <mike@fireburn.co.uk> > Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> > Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> > Tested-by: Mike Lothian <mike@fireburn.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Regards, Joonas
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index e7afad5..3b968ec 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -716,9 +716,9 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm, uint64_t length) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); - unsigned int pte_start = gen8_pte_index(start); unsigned int num_entries = gen8_pte_count(start, length); - uint64_t pte; + unsigned int pte = gen8_pte_index(start); + unsigned int pte_end = pte + num_entries; gen8_pte_t *pt_vaddr; gen8_pte_t scratch_pte = gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC); @@ -726,7 +726,9 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm, if (WARN_ON(!px_page(pt))) return false; - bitmap_clear(pt->used_ptes, pte_start, num_entries); + GEM_BUG_ON(pte_end > GEN8_PTES); + + bitmap_clear(pt->used_ptes, pte, num_entries); if (bitmap_empty(pt->used_ptes, GEN8_PTES)) { free_pt(vm->dev, pt); @@ -735,8 +737,8 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm, pt_vaddr = kmap_px(pt); - for (pte = pte_start; pte < num_entries; pte++) - pt_vaddr[pte] = scratch_pte; + while (pte < pte_end) + pt_vaddr[pte++] = scratch_pte; kunmap_px(ppgtt, pt_vaddr);
Comparing pte index to a number of entries is wrong when clearing a range of pte entries. Use end marker of 'one past' to correctly point adequate number of ptes to the scratch page. v2: assert early instead of warning late (Chris) v3: removed consts (Joonas) Fixes: d209b9c3cd28 ("drm/i915/gtt: Split gen8_ppgtt_clear_pte_range") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98282 Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Michel Thierry <michel.thierry@intel.com> Cc: Michał Winiarski <michal.winiarski@intel.com> Reported-by: Mike Lothian <mike@fireburn.co.uk> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Mike Lothian <mike@fireburn.co.uk> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)