static int udma_alloc_chan_resources()

in ti/k3-udma.c [2156:2359]

• 159 lines of code
• 25 McCabe index (conditional complexity)

static int udma_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_soc_data *soc_data = ud->soc_data;
	struct k3_ring *irq_ring;
	u32 irq_udma_idx;
	int ret;

	uc->dma_dev = ud->dev;

	if (uc->config.pkt_mode || uc->config.dir == DMA_MEM_TO_MEM) {
		uc->use_dma_pool = true;
		/* in case of MEM_TO_MEM we have maximum of two TRs */
		if (uc->config.dir == DMA_MEM_TO_MEM) {
			uc->config.hdesc_size = cppi5_trdesc_calc_size(
					sizeof(struct cppi5_tr_type15_t), 2);
			uc->config.pkt_mode = false;
		}
	}

	if (uc->use_dma_pool) {
		uc->hdesc_pool = dma_pool_create(uc->name, ud->ddev.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_cleanup;
		}
	}

	/*
	 * 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_MEM:
		/* Non synchronized - mem to mem type of transfer */
		dev_dbg(uc->ud->dev, "%s: chan%d as MEM-to-MEM\n", __func__,
			uc->id);

		ret = udma_get_chan_pair(uc);
		if (ret)
			goto err_cleanup;

		ret = udma_alloc_tx_resources(uc);
		if (ret) {
			udma_put_rchan(uc);
			goto err_cleanup;
		}

		ret = udma_alloc_rx_resources(uc);
		if (ret) {
			udma_free_tx_resources(uc);
			goto err_cleanup;
		}

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

		irq_ring = uc->tchan->tc_ring;
		irq_udma_idx = uc->tchan->id;

		ret = udma_tisci_m2m_channel_config(uc);
		break;
	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)
			goto err_cleanup;

		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 = uc->tchan->tc_ring;
		irq_udma_idx = uc->tchan->id;

		ret = udma_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)
			goto err_cleanup;

		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 = uc->rflow->r_ring;
		irq_udma_idx = soc_data->oes.udma_rchan + uc->rchan->id;

		ret = udma_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);
		ret = -EINVAL;
		goto err_cleanup;

	}

	/* 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;
		}
	}

	/* 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 = k3_ringacc_get_ring_irq_num(irq_ring);
	if (uc->irq_num_ring <= 0) {
		dev_err(ud->dev, "Failed to get ring irq (index: %u)\n",
			k3_ringacc_get_ring_id(irq_ring));
		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;
	}

	/* Event from UDMA (TR events) only needed for slave TR mode channels */
	if (is_slave_direction(uc->config.dir) && !uc->config.pkt_mode) {
		uc->irq_num_udma = msi_get_virq(ud->dev, irq_udma_idx);
		if (uc->irq_num_udma <= 0) {
			dev_err(ud->dev, "Failed to get udma irq (index: %u)\n",
				irq_udma_idx);
			free_irq(uc->irq_num_ring, uc);
			ret = -EINVAL;
			goto err_irq_free;
		}

		ret = request_irq(uc->irq_num_udma, udma_udma_irq_handler, 0,
				  uc->name, uc);
		if (ret) {
			dev_err(ud->dev, "chan%d: UDMA irq request failed\n",
				uc->id);
			free_irq(uc->irq_num_ring, uc);
			goto err_irq_free;
		}
	} else {
		uc->irq_num_udma = 0;
	}

	udma_reset_rings(uc);

	return 0;

err_irq_free:
	uc->irq_num_ring = 0;
	uc->irq_num_udma = 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);
err_cleanup:
	udma_reset_uchan(uc);

	if (uc->use_dma_pool) {
		dma_pool_destroy(uc->hdesc_pool);
		uc->use_dma_pool = false;
	}

	return ret;
}