static int pktdma_alloc_chan_resources()

in ti/k3-udma.c [2573:2722]

• 115 lines of code
• 14 McCabe index (conditional complexity)

static int pktdma_alloc_chan_resources(struct dma_chan *chan)
{
	struct udma_chan *uc = to_udma_chan(chan);
	struct udma_dev *ud = to_udma_dev(chan->device);
	const struct udma_oes_offsets *oes = &ud->soc_data->oes;
	u32 irq_ring_idx;
	int ret;

	/*
	 * Make sure that the completion is in a known state:
	 * No teardown, the channel is idle
	 */
	reinit_completion(&uc->teardown_completed);
	complete_all(&uc->teardown_completed);
	uc->state = UDMA_CHAN_IS_IDLE;

	switch (uc->config.dir) {
	case DMA_MEM_TO_DEV:
		/* Slave transfer synchronized - mem to dev (TX) trasnfer */
		dev_dbg(uc->ud->dev, "%s: chan%d as MEM-to-DEV\n", __func__,
			uc->id);

		ret = udma_alloc_tx_resources(uc);
		if (ret) {
			uc->config.remote_thread_id = -1;
			return ret;
		}

		uc->config.src_thread = ud->psil_base + uc->tchan->id;
		uc->config.dst_thread = uc->config.remote_thread_id;
		uc->config.dst_thread |= K3_PSIL_DST_THREAD_ID_OFFSET;

		irq_ring_idx = uc->tchan->tflow_id + oes->pktdma_tchan_flow;

		ret = pktdma_tisci_tx_channel_config(uc);
		break;
	case DMA_DEV_TO_MEM:
		/* Slave transfer synchronized - dev to mem (RX) trasnfer */
		dev_dbg(uc->ud->dev, "%s: chan%d as DEV-to-MEM\n", __func__,
			uc->id);

		ret = udma_alloc_rx_resources(uc);
		if (ret) {
			uc->config.remote_thread_id = -1;
			return ret;
		}

		uc->config.src_thread = uc->config.remote_thread_id;
		uc->config.dst_thread = (ud->psil_base + uc->rchan->id) |
					K3_PSIL_DST_THREAD_ID_OFFSET;

		irq_ring_idx = uc->rflow->id + oes->pktdma_rchan_flow;

		ret = pktdma_tisci_rx_channel_config(uc);
		break;
	default:
		/* Can not happen */
		dev_err(uc->ud->dev, "%s: chan%d invalid direction (%u)\n",
			__func__, uc->id, uc->config.dir);
		return -EINVAL;
	}

	/* check if the channel configuration was successful */
	if (ret)
		goto err_res_free;

	if (udma_is_chan_running(uc)) {
		dev_warn(ud->dev, "chan%d: is running!\n", uc->id);
		udma_reset_chan(uc, false);
		if (udma_is_chan_running(uc)) {
			dev_err(ud->dev, "chan%d: won't stop!\n", uc->id);
			ret = -EBUSY;
			goto err_res_free;
		}
	}

	uc->dma_dev = dmaengine_get_dma_device(chan);
	uc->hdesc_pool = dma_pool_create(uc->name, uc->dma_dev,
					 uc->config.hdesc_size, ud->desc_align,
					 0);
	if (!uc->hdesc_pool) {
		dev_err(ud->ddev.dev,
			"Descriptor pool allocation failed\n");
		uc->use_dma_pool = false;
		ret = -ENOMEM;
		goto err_res_free;
	}

	uc->use_dma_pool = true;

	/* PSI-L pairing */
	ret = navss_psil_pair(ud, uc->config.src_thread, uc->config.dst_thread);
	if (ret) {
		dev_err(ud->dev, "PSI-L pairing failed: 0x%04x -> 0x%04x\n",
			uc->config.src_thread, uc->config.dst_thread);
		goto err_res_free;
	}

	uc->psil_paired = true;

	uc->irq_num_ring = msi_get_virq(ud->dev, irq_ring_idx);
	if (uc->irq_num_ring <= 0) {
		dev_err(ud->dev, "Failed to get ring irq (index: %u)\n",
			irq_ring_idx);
		ret = -EINVAL;
		goto err_psi_free;
	}

	ret = request_irq(uc->irq_num_ring, udma_ring_irq_handler,
			  IRQF_TRIGGER_HIGH, uc->name, uc);
	if (ret) {
		dev_err(ud->dev, "chan%d: ring irq request failed\n", uc->id);
		goto err_irq_free;
	}

	uc->irq_num_udma = 0;

	udma_reset_rings(uc);

	INIT_DELAYED_WORK_ONSTACK(&uc->tx_drain.work,
				  udma_check_tx_completion);

	if (uc->tchan)
		dev_dbg(ud->dev,
			"chan%d: tchan%d, tflow%d, Remote thread: 0x%04x\n",
			uc->id, uc->tchan->id, uc->tchan->tflow_id,
			uc->config.remote_thread_id);
	else if (uc->rchan)
		dev_dbg(ud->dev,
			"chan%d: rchan%d, rflow%d, Remote thread: 0x%04x\n",
			uc->id, uc->rchan->id, uc->rflow->id,
			uc->config.remote_thread_id);
	return 0;

err_irq_free:
	uc->irq_num_ring = 0;
err_psi_free:
	navss_psil_unpair(ud, uc->config.src_thread, uc->config.dst_thread);
	uc->psil_paired = false;
err_res_free:
	udma_free_tx_resources(uc);
	udma_free_rx_resources(uc);

	udma_reset_uchan(uc);

	dma_pool_destroy(uc->hdesc_pool);
	uc->use_dma_pool = false;

	return ret;
}