[Intel-gfx] [PATCH v2 3/8] drm/i915/stolen: consider I915_BO_ALLOC_GPU_ONLY

[Matthew Auld]

Keep the behaviour consistent with normal lmem, where we assume CPU
access if by default required.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index 6df1600708a7..369a2a60bd7a 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -695,6 +695,14 @@ static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,
 	if (size == 0)
 		return -EINVAL;
 
+	/*
+	 * With discrete devices, where we lack a mappable aperture there is no
+	 * possible way to ever access this memory on the CPU side.
+	 */
+	if (mem->type == INTEL_MEMORY_STOLEN_LOCAL && !mem->io_size &&
+	    !(flags & I915_BO_ALLOC_GPU_ONLY))
+		return -ENOSPC;
+
 	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 	if (!stolen)
 		return -ENOMEM;
-- 
2.34.1