drm/xe: Always check force_wake_get return code

A force_wake_get failure means that the HW might not be awake for the
access we're doing; this can lead to an immediate error or it can be a
more subtle problem (e.g. a register read might return an incorrect
value that is still valid, leading the driver to make a wrong choice
instead of flagging an error).
We avoid an error from the force_wake function because callers might
handle or tolerate the error, but this only works if all callers
are checking the error code. The majority already do, but a few are not.
These are mainly falling into 3 categories, which are each handled
differently:

1) error capture: in this case we want to continue the capture, but we
   log an info message in dmesg to notify the user that the capture
   might have incorrect data.

2) ioctl: in this case we return a -EIO error to userspace

3) unabortable actions: these are scenarios where we can't simply abort
   and retry and so it's better to just try it anyway because there is a
   chance the HW is awake even with the failure. In this case we throw a
   warning so we know there was a forcewake problem if something fails
   down the line.

v2: use gt_WARN_ON where appropriate

Signed-off-by: Daniele Ceraolo Spurio <[email protected]>
Cc: Tejas Upadhyay <[email protected]>
Reviewed-by: Matt Roper <[email protected]>
Reviewed-by: Tejas Upadhyay <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

drivers/gpu/drm/xe/xe_devcoredump.c

@@ -13,6 +13,7 @@
 #include "xe_exec_queue.h"
 #include "xe_force_wake.h"
 #include "xe_gt.h"
+#include "xe_gt_printk.h"
 #include "xe_guc_ct.h"
 #include "xe_guc_submit.h"
 #include "xe_hw_engine.h"
@@ -64,7 +65,9 @@ static void xe_devcoredump_deferred_snap_work(struct work_struct *work)
 {
 	struct xe_devcoredump_snapshot *ss = container_of(work, typeof(*ss), work);
 
-	xe_force_wake_get(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL);
+	/* keep going if fw fails as we still want to save the memory and SW data */
+	if (xe_force_wake_get(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL))
+		xe_gt_info(ss->gt, "failed to get forcewake for coredump capture\n");
 	xe_vm_snapshot_capture_delayed(ss->vm);
 	xe_guc_exec_queue_snapshot_capture_delayed(ss->ge);
 	xe_force_wake_put(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL);
@@ -180,7 +183,9 @@ static void devcoredump_snapshot(struct xe_devcoredump *coredump,
 		}
 	}
 
-	xe_force_wake_get(gt_to_fw(q->gt), XE_FORCEWAKE_ALL);
+	/* keep going if fw fails as we still want to save the memory and SW data */
+	if (xe_force_wake_get(gt_to_fw(q->gt), XE_FORCEWAKE_ALL))
+		xe_gt_info(ss->gt, "failed to get forcewake for coredump capture\n");
 
 	coredump->snapshot.ct = xe_guc_ct_snapshot_capture(&guc->ct, true);
 	coredump->snapshot.ge = xe_guc_exec_queue_snapshot_capture(job);

drivers/gpu/drm/xe/xe_gsc.c

@@ -281,7 +281,7 @@ static void gsc_work(struct work_struct *work)
 	int ret;
 
 	xe_pm_runtime_get(xe);
-	xe_force_wake_get(gt_to_fw(gt), XE_FW_GSC);
+	xe_gt_WARN_ON(gt, xe_force_wake_get(gt_to_fw(gt), XE_FW_GSC));
 
 	ret = gsc_upload_and_init(gsc);
 	if (ret && ret != -EEXIST)

drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c

@@ -249,7 +249,7 @@ int xe_gt_tlb_invalidation_ggtt(struct xe_gt *gt)
 
 		xe_gt_tlb_invalidation_wait(gt, seqno);
 	} else if (xe_device_uc_enabled(xe)) {
-		xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
+		xe_gt_WARN_ON(gt, xe_force_wake_get(gt_to_fw(gt), XE_FW_GT));
 		if (xe->info.platform == XE_PVC || GRAPHICS_VER(xe) >= 20) {
 			xe_mmio_write32(gt, PVC_GUC_TLB_INV_DESC1,
 					PVC_GUC_TLB_INV_DESC1_INVALIDATE);

drivers/gpu/drm/xe/xe_guc.c

@@ -240,10 +240,11 @@ static void guc_write_params(struct xe_guc *guc)
 static void guc_fini(struct drm_device *drm, void *arg)
 {
 	struct xe_guc *guc = arg;
+	struct xe_gt *gt = guc_to_gt(guc);
 
-	xe_force_wake_get(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL);
+	xe_gt_WARN_ON(gt, xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL));
 	xe_uc_fini_hw(&guc_to_gt(guc)->uc);
-	xe_force_wake_put(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL);
+	xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL);
 }
 
 /**

drivers/gpu/drm/xe/xe_guc_pc.c

@@ -927,7 +927,7 @@ static void xe_guc_pc_fini(struct drm_device *drm, void *arg)
 		return;
 	}
 
-	xe_force_wake_get(gt_to_fw(pc_to_gt(pc)), XE_FORCEWAKE_ALL);
+	XE_WARN_ON(xe_force_wake_get(gt_to_fw(pc_to_gt(pc)), XE_FORCEWAKE_ALL));
 	XE_WARN_ON(xe_guc_pc_gucrc_disable(pc));
 	XE_WARN_ON(xe_guc_pc_stop(pc));
 	xe_force_wake_put(gt_to_fw(pc_to_gt(pc)), XE_FORCEWAKE_ALL);

drivers/gpu/drm/xe/xe_guc_submit.c

@@ -833,7 +833,9 @@ static void simple_error_capture(struct xe_exec_queue *q)
 			}
 		}
 
-		xe_force_wake_get(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL);
+		if (xe_force_wake_get(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL))
+			xe_gt_info(guc_to_gt(guc),
+				   "failed to get forcewake for error capture");
 		xe_guc_ct_print(&guc->ct, &p, true);
 		guc_exec_queue_print(q, &p);
 		for_each_hw_engine(hwe, guc_to_gt(guc), id) {

drivers/gpu/drm/xe/xe_query.c

@@ -150,7 +150,8 @@ query_engine_cycles(struct xe_device *xe,
 	if (!hwe)
 		return -EINVAL;
 
-	xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
+	if (xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL))
+		return -EIO;
 
 	__read_timestamps(gt,
 			  RING_TIMESTAMP(hwe->mmio_base),