drm/msm: Fix null pointer dereferences without iommu

Check if 'aspace' is set before using it as it will stay null without
IOMMU, such as on msm8974.

Fixes: bc211258 ("drm/msm/gpu: Track global faults per address-space")
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Link: https://lore.kernel.org/r/20220421203455.313523-1-luca@z3ntu.xyzSigned-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -276,7 +276,10 @@ int adreno_get_param(struct msm_gpu *gpu, struct msm_file_private *ctx,
 		*value = 0;
 		return 0;
 	case MSM_PARAM_FAULTS:
+		if (ctx->aspace)
 			*value = gpu->global_faults + ctx->aspace->faults;
+		else
+			*value = gpu->global_faults;
 		return 0;
 	case MSM_PARAM_SUSPENDS:
 		*value = gpu->suspend_count;

drivers/gpu/drm/msm/msm_gpu.c

@@ -391,6 +391,7 @@ static void recover_worker(struct kthread_work *work)
 	if (submit) {
 		/* Increment the fault counts */
 		submit->queue->faults++;
+		if (submit->aspace)
 			submit->aspace->faults++;
 
 		get_comm_cmdline(submit, &comm, &cmd);