From 65332b097c2bfd42a5feb0050ce0998eb3c4655c Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon, 11 May 2020 11:35:52 +0200
Subject: drm/shmem-helpers: Redirect mmap for imported dma-buf
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Git-commit: 26d3ac3cb04d171a861952e89324e347598a347f
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Currently this seems to work by converting the sgt into a pages array,
and then treating it like a native object. Do the right thing and
redirect mmap to the exporter.

With this nothing is calling get_pages anymore on imported dma-buf,
and we can start to remove the use of the ->pages array for that case.

v2: Rebase

Tested-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200511093554.211493-8-daniel.vetter@ffwll.ch
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 0aac83ed9f5d..afe9668f1750 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -551,6 +551,9 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	/* Remove the fake offset */
 	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
 
+	if (obj->import_attach)
+		return dma_buf_mmap(obj->dma_buf, vma, 0);
+
 	shmem = to_drm_gem_shmem_obj(obj);
 
 	ret = drm_gem_shmem_get_pages(shmem);
-- 
2.29.2