[PATCH RESEND 1/2] drm/gpuvm: Send in-place re-maps to the driver as remap

[Rob Clark <robin.clark@oss.qualcomm.com>]

The 'keep' hint on the unmap is only half useful, without being able to
link it to a map cb.  Instead combine the two ops into a remap op to
give the driver a chance to figure things out.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/drm_gpuvm.c            | 21 +++++++++++++++++++++
 drivers/gpu/drm/nouveau/nouveau_uvmm.c |  3 ++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
index bbc7fecb6f4a..e21782a97fbe 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -2125,6 +2125,27 @@ __drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm,
 				 offset == req_offset;
 
 			if (end == req_end) {
+				if (merge) {
+					/*
+					 * This is an exact remap of the existing
+					 * VA (potentially flags change)?  Pass
+					 * this to the driver as a remap so it can
+					 * do an in-place update:
+					 */
+					struct drm_gpuva_op_map n = {
+						.va.addr = va->va.addr,
+						.va.range = va->va.range,
+						.gem.obj = va->gem.obj,
+						.gem.offset = va->gem.offset,
+					};
+					struct drm_gpuva_op_unmap u = {
+						.va = va,
+						.keep = true,
+					};
+
+					return op_remap_cb(ops, priv, NULL, &n, &u);
+				}
+
 				ret = op_unmap_cb(ops, priv, va, merge);
 				if (ret)
 					return ret;
diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
index 48f105239f42..c3e3a15eb3c8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
@@ -820,7 +820,8 @@ op_remap(struct drm_gpuva_op_remap *r,
 	if (r->next)
 		end = r->next->va.addr;
 
-	op_unmap_range(u, addr, end - addr);
+	if (!u->keep)
+		op_unmap_range(u, addr, end - addr);
 }
 
 static int
-- 
2.50.1