From: Boris Brezillon boris.brezillon@collabora.com
commit f45da8204ff1707c529a8769f5467ff16f504b26 upstream.
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 Link: https://patchwork.freedesktop.org/patch/msgid/20210205111757.585248-3-boris.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- 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(s } 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(s
dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
+out: panfrost_gem_mapping_put(bomapping);
return 0;