[PATCH v2 1/2] drm/i915/gem: Adjust vma offset for framebuffer mmap offset

[Andi Shyti <andi.shyti@linux.intel.com>]

When mapping a framebuffer object, the virtual memory area (VMA)
offset ('vm_pgoff') should be adjusted by the start of the
'vma_node' associated with the object. This ensures that the VMA
offset is correctly aligned with the corresponding offset within
the GGTT aperture.

Increment vm_pgoff by the start of the vma_node with the offset=
provided by the user.

Suggested-by: Chris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_mman.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index a2195e28b625..ce10dd259812 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -1084,6 +1084,8 @@ int i915_gem_fb_mmap(struct drm_i915_gem_object *obj, struct vm_area_struct *vma
 		mmo = mmap_offset_attach(obj, mmap_type, NULL);
 		if (IS_ERR(mmo))
 			return PTR_ERR(mmo);
+
+		vma->vm_pgoff += drm_vma_node_start(&mmo->vma_node);
 	}
 
 	/*
-- 
2.45.2