This was always the way it was supposed to work, and when we drop the page array for imported dma-bufs our fault handling path will no longer work.
Signed-off-by: Rob Clark <[email protected]> --- drivers/gpu/drm/msm/msm_gem.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index e8390ebd5dd5..c90336b3b231 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -23,6 +23,8 @@ #include "msm_gpu.h" #include "msm_kms.h" +MODULE_IMPORT_NS("DMA_BUF"); + static void update_device_mem(struct msm_drm_private *priv, ssize_t size) { uint64_t total_mem = atomic64_add_return(size, &priv->total_mem); @@ -338,6 +340,9 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf) int err; vm_fault_t ret; + if (drm_WARN_ON_ONCE(obj->dev, drm_gem_is_imported(obj))) + return VM_FAULT_SIGBUS; + /* * vm_ops.open/drm_gem_mmap_obj and close get and put * a reference on obj. So, we dont need to hold one here. @@ -1126,6 +1131,25 @@ static int msm_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct { struct msm_gem_object *msm_obj = to_msm_bo(obj); + if (drm_gem_is_imported(obj)) { + int ret; + + /* Reset both vm_ops and vm_private_data, so we don't end up with + * vm_ops pointing to our implementation if the dma-buf backend + * doesn't set those fields. + */ + vma->vm_private_data = NULL; + vma->vm_ops = NULL; + + ret = dma_buf_mmap(obj->dma_buf, vma, 0); + + /* Drop the reference drm_gem_mmap_obj() acquired.*/ + if (!ret) + drm_gem_object_put(obj); + + return ret; + } + vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); vma->vm_page_prot = msm_gem_pgprot(msm_obj, vma_get_page_prot(vma)); -- 2.55.0
