Add XE_BO_FLAG_CPU_ADDR_MIRROR to indicate BO is tied to SVM range.
While these BO's are kernel allocations, we need a VM reference in this
case which this flag indicates. In addition, we do not support CCS on
these BO's either. The later can be revisited later.

v2:
 - Take VM ref for system allocator BOs
v3:
 - s/XE_BO_FLAG_SYSTEM_ALLOC/XE_BO_FLAG_CPU_ADDR_MIRROR (Thomas)
 - Better commit message (Thomas)
 - Drop XE_BO_FLAG_SKIP_CLEAR for now
 - Add comment about possibly supporting CCS (Thomas)
v4:
 - Fix alignment issue (Checkpatch)

Signed-off-by: Matthew Brost <matthew.br...@intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c | 12 ++++++++----
 drivers/gpu/drm/xe/xe_bo.h |  1 +
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index e914a60b8afc..20c96709e267 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1239,7 +1239,7 @@ static void xe_ttm_bo_destroy(struct ttm_buffer_object 
*ttm_bo)
                xe_drm_client_remove_bo(bo);
 #endif
 
-       if (bo->vm && xe_bo_is_user(bo))
+       if (bo->vm && (xe_bo_is_user(bo) || bo->flags & 
XE_BO_FLAG_CPU_ADDR_MIRROR))
                xe_vm_put(bo->vm);
 
        mutex_lock(&xe->mem_access.vram_userfault.lock);
@@ -1435,7 +1435,8 @@ struct xe_bo *___xe_bo_create_locked(struct xe_device 
*xe, struct xe_bo *bo,
        int err;
 
        /* Only kernel objects should set GT */
-       xe_assert(xe, !tile || type == ttm_bo_type_kernel);
+       xe_assert(xe, !tile || type == ttm_bo_type_kernel ||
+                 flags & XE_BO_FLAG_CPU_ADDR_MIRROR);
 
        if (XE_WARN_ON(!size)) {
                xe_bo_free(bo);
@@ -1631,7 +1632,7 @@ __xe_bo_create_locked(struct xe_device *xe,
         * by having all the vm's bo refereferences released at vm close
         * time.
         */
-       if (vm && xe_bo_is_user(bo))
+       if (vm && (xe_bo_is_user(bo) || bo->flags & XE_BO_FLAG_CPU_ADDR_MIRROR))
                xe_vm_get(vm);
        bo->vm = vm;
 
@@ -2503,8 +2504,11 @@ bool xe_bo_needs_ccs_pages(struct xe_bo *bo)
         * system memory (i.e., it allows XE_PL_TT placement), FlatCCS
         * can't be used since there's no CCS storage associated with
         * non-VRAM addresses.
+        *
+        * XXX: Can we support CCS with CPU address mirroring?
         */
-       if (IS_DGFX(xe) && (bo->flags & XE_BO_FLAG_SYSTEM))
+       if (IS_DGFX(xe) && ((bo->flags & XE_BO_FLAG_SYSTEM) ||
+                           (bo->flags & XE_BO_FLAG_CPU_ADDR_MIRROR)))
                return false;
 
        return true;
diff --git a/drivers/gpu/drm/xe/xe_bo.h b/drivers/gpu/drm/xe/xe_bo.h
index ce55a2bb13f6..c01ed535a8c3 100644
--- a/drivers/gpu/drm/xe/xe_bo.h
+++ b/drivers/gpu/drm/xe/xe_bo.h
@@ -47,6 +47,7 @@
                                         XE_BO_FLAG_GGTT1 | \
                                         XE_BO_FLAG_GGTT2 | \
                                         XE_BO_FLAG_GGTT3)
+#define XE_BO_FLAG_CPU_ADDR_MIRROR     BIT(22)
 
 /* this one is trigger internally only */
 #define XE_BO_FLAG_INTERNAL_TEST       BIT(30)
-- 
2.34.1

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