drm/i915: Allow relocation deltas outside of target bo

Userspace has a legitimate requirement to use a delta that points to
outside of the target bo, and so we need to enable this. (As this is an
abi break, albeit a relaxation of the current restrictions, mark the change
with a new flag.)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

2 files changed, 3 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ffa2196eb3b9..51150692af2d 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -772,6 +772,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
         case I915_PARAM_HAS_EXEC_CONSTANTS:
                 value = INTEL_INFO(dev)->gen >= 4;
                 break;
+        case I915_PARAM_HAS_RELAXED_DELTA:
+                value = 1;
+                break;
         default:
                 DRM_DEBUG_DRIVER("Unknown parameter %d\n",
                                  param->param);
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 71a4a3b69158..1c3b76a8a6fb 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -350,16 +350,6 @@ i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj,
                 return ret;
         }
 
-        /* and points to somewhere within the target object. */
-        if (unlikely(reloc->delta >= target_obj->size)) {
-                DRM_ERROR("Relocation beyond target object bounds: "
-                          "obj %p target %d delta %d size %d.\n",
-                          obj, reloc->target_handle,
-                          (int) reloc->delta,
-                          (int) target_obj->size);
-                return ret;
-        }
-
         reloc->delta += target_offset;
         if (obj->base.write_domain == I915_GEM_DOMAIN_CPU) {
                 uint32_t page_offset = reloc->offset & ~PAGE_MASK;