drm/msm: Reject MAP_NULL op if no PRR

We need PRR support in order to implement MAP_NULL.  Userspace shouldn't
be trying to use this if it is unsupported.

Reported-by: Valentine Burley <valentine.burley@collabora.com>
Link: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37935#note_3153730
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Tested-by: Valentine Burley <valentine.burley@collabora.com>
Patchwork: https://patchwork.freedesktop.org/patch/682941/
Message-ID: <20251022222051.10030-1-robin.clark@oss.qualcomm.com>

Author: Rob Clark

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

@@ -348,13 +348,6 @@ int adreno_fault_handler(struct msm_gpu *gpu, unsigned long iova, int flags,
 	return 0;
 }
 
-static bool
-adreno_smmu_has_prr(struct msm_gpu *gpu)
-{
-	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(&gpu->pdev->dev);
-	return adreno_smmu && adreno_smmu->set_prr_addr;
-}
-
 int adreno_get_param(struct msm_gpu *gpu, struct msm_context *ctx,
 		     uint32_t param, uint64_t *value, uint32_t *len)
 {

drivers/gpu/drm/msm/msm_gem_vma.c

@@ -964,6 +964,7 @@ static int
 lookup_op(struct msm_vm_bind_job *job, const struct drm_msm_vm_bind_op *op)
 {
 	struct drm_device *dev = job->vm->drm;
+	struct msm_drm_private *priv = dev->dev_private;
 	int i = job->nr_ops++;
 	int ret = 0;
 
@@ -1010,6 +1011,11 @@ lookup_op(struct msm_vm_bind_job *job, const struct drm_msm_vm_bind_op *op)
 		break;
 	}
 
+	if ((op->op == MSM_VM_BIND_OP_MAP_NULL) &&
+	    !adreno_smmu_has_prr(priv->gpu)) {
+		ret = UERR(EINVAL, dev, "PRR not supported\n");
+	}
+
 	return ret;
 }
 

drivers/gpu/drm/msm/msm_gpu.h

@@ -299,6 +299,17 @@ static inline struct msm_gpu *dev_to_gpu(struct device *dev)
 	return container_of(adreno_smmu, struct msm_gpu, adreno_smmu);
 }
 
+static inline bool
+adreno_smmu_has_prr(struct msm_gpu *gpu)
+{
+	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(&gpu->pdev->dev);
+
+	if (!adreno_smmu)
+		return false;
+
+	return adreno_smmu && adreno_smmu->set_prr_addr;
+}
+
 /* It turns out that all targets use the same ringbuffer size */
 #define MSM_GPU_RINGBUFFER_SZ SZ_32K
 #define MSM_GPU_RINGBUFFER_BLKSIZE 32