| Message ID | 20210201082116.267208-3-boris.brezillon@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panfrost: MMU fixes | expand |
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; >
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;
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> --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)