On 01/02/2021 08:21, Boris Brezillon wrote:

We allocate 2MB chunks at a time, so it might appear that a page fault has already been handled by a previous page fault when we reach panfrost_mmu_map_fault_addr(). Bail out in that case to avoid mapping the same area twice.

Cc: stable@vger.kernel.org Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations") Signed-off-by: Boris Brezillon boris.brezillon@collabora.com

Reviewed-by: Steven Price steven.price@arm.com

---

drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index 904d63450862..21e552d1ac71 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -488,8 +488,14 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, } bo->base.pages = pages; bo->base.pages_use_count = 1;

• } else

• } else { pages = bo->base.pages;

• if (pages[page_offset]) {
  

• 	/* Pages are already mapped, bail out. */
  

• 	mutex_unlock(&bo->base.pages_lock);
  

• 	goto out;
  

• }
  

• }

mapping = bo->base.base.filp->f_mapping; mapping_set_unevictable(mapping); @@ -522,6 +528,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr); +out: panfrost_gem_mapping_put(bomapping); return 0;