Re: [PATCH 2/2] dmaengine: qcom: bam_dma: SCM-assign descriptor FIFOs to a remote VMID

[Konrad Dybcio]

On 7/14/26 7:00 AM, Vishnu Santhosh wrote:
> On Qualcomm SoCs where the BAM is powered by a remote processor that
> enforces XPU access control (e.g. the mDSP on Shikra, VMID 43 / NAV),
> the BAM reads the descriptor FIFO as an AXI master under the remote
> execution environment. Without an SCM grant for the remote VMID, the
> first descriptor enqueue faults with an XPU violation.

[...]

> +	ret = of_property_read_u32_array(dev->of_node, "qcom,vmid",
> +					 bdev->vmids, n);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < n; i++) {
> +		if (bdev->vmids[i] == QCOM_SCM_VMID_HLOS) {
> +			dev_err(dev, "qcom,vmid must not include HLOS (%u)\n",
> +				QCOM_SCM_VMID_HLOS);
> +			return -EINVAL;
> +		}
> +	}

Please switch to device_property_ instead

[...]

> +static int bam_assign_fifo(struct bam_device *bdev, struct bam_chan *bchan)
> +{
> +	struct qcom_scm_vmperm *dst __free(kfree) = NULL;
> +	u64 src = BIT_ULL(QCOM_SCM_VMID_HLOS);
> +	int i, ret;
> +
> +	if (!bdev->num_vmids)
> +		return 0;
> +
> +	dst = kcalloc(bdev->num_vmids + 1, sizeof(*dst), GFP_KERNEL);
> +	if (!dst)
> +		return -ENOMEM;

Please reshuffle this to follow

7c4c14ad3d8c ("tee: qcomtee: mem: Fix confusing cleanup.h syntax")

Konrad