[PATCH v2 1/2] drm/xe: improve hibernation on igpu

[Matthew Brost]

From: Matthew Auld <matthew.auld at intel.com>

The GGTT looks to be stored inside stolen memory on igpu which is not
treated as normal RAM.  The core kernel skips this memory range when
creating the hibernation image, therefore when coming back from
hibernation the GGTT programming is lost. This seems to cause issues
with broken resume where GuC FW fails to load:

[drm] *ERROR* GT0: load failed: status = 0x400000A0, time = 10ms, freq = 1250MHz (req 1300MHz), done = -1
[drm] *ERROR* GT0: load failed: status: Reset = 0, BootROM = 0x50, UKernel = 0x00, MIA = 0x00, Auth = 0x01
[drm] *ERROR* GT0: firmware signature verification failed
[drm] *ERROR* CRITICAL: Xe has declared device 0000:00:02.0 as wedged.

Current GGTT users are kernel internal and tracked as pinned, so it
should be possible to hook into the existing save/restore logic that we
use for dgpu, where the actual evict is skipped but on restore we
importantly restore the GGTT programming.  This has been confirmed to
fix hibernation on at least ADL and MTL, though likely all igpu
platforms are affected.

This also means we have a hole in our testing, where the existing s4
tests only really test the driver hooks, and don't go as far as actually
rebooting and restoring from the hibernation image and in turn powering
down RAM (and therefore losing the contents of stolen).

v2 (Brost)
 - Remove extra newline and drop unnecessary parentheses.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3275
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: <stable at vger.kernel.org> # v6.8+
Reviewed-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c       | 37 ++++++++++++++------------------
 drivers/gpu/drm/xe/xe_bo_evict.c |  6 ------
 2 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 8286cbc23721..549866da5cd1 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -952,7 +952,10 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
 	if (WARN_ON(!xe_bo_is_pinned(bo)))
 		return -EINVAL;
 
-	if (WARN_ON(xe_bo_is_vram(bo) || !bo->ttm.ttm))
+	if (WARN_ON(xe_bo_is_vram(bo)))
+		return -EINVAL;
+
+	if (WARN_ON(!bo->ttm.ttm && !xe_bo_is_stolen(bo)))
 		return -EINVAL;
 
 	if (!mem_type_is_vram(place->mem_type))
@@ -1774,6 +1777,7 @@ int xe_bo_pin_external(struct xe_bo *bo)
 
 int xe_bo_pin(struct xe_bo *bo)
 {
+	struct ttm_place *place = &bo->placements[0];
 	struct xe_device *xe = xe_bo_device(bo);
 	int err;
 
@@ -1804,8 +1808,6 @@ int xe_bo_pin(struct xe_bo *bo)
 	 */
 	if (IS_DGFX(xe) && !(IS_ENABLED(CONFIG_DRM_XE_DEBUG) &&
 	    bo->flags & XE_BO_FLAG_INTERNAL_TEST)) {
-		struct ttm_place *place = &(bo->placements[0]);
-
 		if (mem_type_is_vram(place->mem_type)) {
 			xe_assert(xe, place->flags & TTM_PL_FLAG_CONTIGUOUS);
 
@@ -1813,13 +1815,12 @@ int xe_bo_pin(struct xe_bo *bo)
 				       vram_region_gpu_offset(bo->ttm.resource)) >> PAGE_SHIFT;
 			place->lpfn = place->fpfn + (bo->size >> PAGE_SHIFT);
 		}
+	}
 
-		if (mem_type_is_vram(place->mem_type) ||
-		    bo->flags & XE_BO_FLAG_GGTT) {
-			spin_lock(&xe->pinned.lock);
-			list_add_tail(&bo->pinned_link, &xe->pinned.kernel_bo_present);
-			spin_unlock(&xe->pinned.lock);
-		}
+	if (mem_type_is_vram(place->mem_type) || bo->flags & XE_BO_FLAG_GGTT) {
+		spin_lock(&xe->pinned.lock);
+		list_add_tail(&bo->pinned_link, &xe->pinned.kernel_bo_present);
+		spin_unlock(&xe->pinned.lock);
 	}
 
 	ttm_bo_pin(&bo->ttm);
@@ -1867,24 +1868,18 @@ void xe_bo_unpin_external(struct xe_bo *bo)
 
 void xe_bo_unpin(struct xe_bo *bo)
 {
+	struct ttm_place *place = &bo->placements[0];
 	struct xe_device *xe = xe_bo_device(bo);
 
 	xe_assert(xe, !bo->ttm.base.import_attach);
 	xe_assert(xe, xe_bo_is_pinned(bo));
 
-	if (IS_DGFX(xe) && !(IS_ENABLED(CONFIG_DRM_XE_DEBUG) &&
-	    bo->flags & XE_BO_FLAG_INTERNAL_TEST)) {
-		struct ttm_place *place = &(bo->placements[0]);
-
-		if (mem_type_is_vram(place->mem_type) ||
-		    bo->flags & XE_BO_FLAG_GGTT) {
-			spin_lock(&xe->pinned.lock);
-			xe_assert(xe, !list_empty(&bo->pinned_link));
-			list_del_init(&bo->pinned_link);
-			spin_unlock(&xe->pinned.lock);
-		}
+	if (mem_type_is_vram(place->mem_type) || bo->flags & XE_BO_FLAG_GGTT) {
+		spin_lock(&xe->pinned.lock);
+		xe_assert(xe, !list_empty(&bo->pinned_link));
+		list_del_init(&bo->pinned_link);
+		spin_unlock(&xe->pinned.lock);
 	}
-
 	ttm_bo_unpin(&bo->ttm);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_bo_evict.c b/drivers/gpu/drm/xe/xe_bo_evict.c
index 32043e1e5a86..b01bc20eb90b 100644
--- a/drivers/gpu/drm/xe/xe_bo_evict.c
+++ b/drivers/gpu/drm/xe/xe_bo_evict.c
@@ -34,9 +34,6 @@ int xe_bo_evict_all(struct xe_device *xe)
 	u8 id;
 	int ret;
 
-	if (!IS_DGFX(xe))
-		return 0;
-
 	/* User memory */
 	for (mem_type = XE_PL_VRAM0; mem_type <= XE_PL_VRAM1; ++mem_type) {
 		struct ttm_resource_manager *man =
@@ -125,9 +122,6 @@ int xe_bo_restore_kernel(struct xe_device *xe)
 	struct xe_bo *bo;
 	int ret;
 
-	if (!IS_DGFX(xe))
-		return 0;
-
 	spin_lock(&xe->pinned.lock);
 	for (;;) {
 		bo = list_first_entry_or_null(&xe->pinned.evicted,
-- 
2.34.1