static int tsi148_dma_list_add()

in bridges/vme_tsi148.c [1620:1774]

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

static int tsi148_dma_list_add(struct vme_dma_list *list,
	struct vme_dma_attr *src, struct vme_dma_attr *dest, size_t count)
{
	struct tsi148_dma_entry *entry, *prev;
	u32 address_high, address_low, val;
	struct vme_dma_pattern *pattern_attr;
	struct vme_dma_pci *pci_attr;
	struct vme_dma_vme *vme_attr;
	int retval = 0;
	struct vme_bridge *tsi148_bridge;

	tsi148_bridge = list->parent->parent;

	/* Descriptor must be aligned on 64-bit boundaries */
	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
	if (!entry) {
		retval = -ENOMEM;
		goto err_mem;
	}

	/* Test descriptor alignment */
	if ((unsigned long)&entry->descriptor & 0x7) {
		dev_err(tsi148_bridge->parent, "Descriptor not aligned to 8 "
			"byte boundary as required: %p\n",
			&entry->descriptor);
		retval = -EINVAL;
		goto err_align;
	}

	/* Given we are going to fill out the structure, we probably don't
	 * need to zero it, but better safe than sorry for now.
	 */
	memset(&entry->descriptor, 0, sizeof(entry->descriptor));

	/* Fill out source part */
	switch (src->type) {
	case VME_DMA_PATTERN:
		pattern_attr = src->private;

		entry->descriptor.dsal = cpu_to_be32(pattern_attr->pattern);

		val = TSI148_LCSR_DSAT_TYP_PAT;

		/* Default behaviour is 32 bit pattern */
		if (pattern_attr->type & VME_DMA_PATTERN_BYTE)
			val |= TSI148_LCSR_DSAT_PSZ;

		/* It seems that the default behaviour is to increment */
		if ((pattern_attr->type & VME_DMA_PATTERN_INCREMENT) == 0)
			val |= TSI148_LCSR_DSAT_NIN;
		entry->descriptor.dsat = cpu_to_be32(val);
		break;
	case VME_DMA_PCI:
		pci_attr = src->private;

		reg_split((unsigned long long)pci_attr->address, &address_high,
			&address_low);
		entry->descriptor.dsau = cpu_to_be32(address_high);
		entry->descriptor.dsal = cpu_to_be32(address_low);
		entry->descriptor.dsat = cpu_to_be32(TSI148_LCSR_DSAT_TYP_PCI);
		break;
	case VME_DMA_VME:
		vme_attr = src->private;

		reg_split((unsigned long long)vme_attr->address, &address_high,
			&address_low);
		entry->descriptor.dsau = cpu_to_be32(address_high);
		entry->descriptor.dsal = cpu_to_be32(address_low);
		entry->descriptor.dsat = cpu_to_be32(TSI148_LCSR_DSAT_TYP_VME);

		retval = tsi148_dma_set_vme_src_attributes(
			tsi148_bridge->parent, &entry->descriptor.dsat,
			vme_attr->aspace, vme_attr->cycle, vme_attr->dwidth);
		if (retval < 0)
			goto err_source;
		break;
	default:
		dev_err(tsi148_bridge->parent, "Invalid source type\n");
		retval = -EINVAL;
		goto err_source;
	}

	/* Assume last link - this will be over-written by adding another */
	entry->descriptor.dnlau = cpu_to_be32(0);
	entry->descriptor.dnlal = cpu_to_be32(TSI148_LCSR_DNLAL_LLA);

	/* Fill out destination part */
	switch (dest->type) {
	case VME_DMA_PCI:
		pci_attr = dest->private;

		reg_split((unsigned long long)pci_attr->address, &address_high,
			&address_low);
		entry->descriptor.ddau = cpu_to_be32(address_high);
		entry->descriptor.ddal = cpu_to_be32(address_low);
		entry->descriptor.ddat = cpu_to_be32(TSI148_LCSR_DDAT_TYP_PCI);
		break;
	case VME_DMA_VME:
		vme_attr = dest->private;

		reg_split((unsigned long long)vme_attr->address, &address_high,
			&address_low);
		entry->descriptor.ddau = cpu_to_be32(address_high);
		entry->descriptor.ddal = cpu_to_be32(address_low);
		entry->descriptor.ddat = cpu_to_be32(TSI148_LCSR_DDAT_TYP_VME);

		retval = tsi148_dma_set_vme_dest_attributes(
			tsi148_bridge->parent, &entry->descriptor.ddat,
			vme_attr->aspace, vme_attr->cycle, vme_attr->dwidth);
		if (retval < 0)
			goto err_dest;
		break;
	default:
		dev_err(tsi148_bridge->parent, "Invalid destination type\n");
		retval = -EINVAL;
		goto err_dest;
	}

	/* Fill out count */
	entry->descriptor.dcnt = cpu_to_be32((u32)count);

	/* Add to list */
	list_add_tail(&entry->list, &list->entries);

	entry->dma_handle = dma_map_single(tsi148_bridge->parent,
					   &entry->descriptor,
					   sizeof(entry->descriptor),
					   DMA_TO_DEVICE);
	if (dma_mapping_error(tsi148_bridge->parent, entry->dma_handle)) {
		dev_err(tsi148_bridge->parent, "DMA mapping error\n");
		retval = -EINVAL;
		goto err_dma;
	}

	/* Fill out previous descriptors "Next Address" */
	if (entry->list.prev != &list->entries) {
		reg_split((unsigned long long)entry->dma_handle, &address_high,
			&address_low);
		prev = list_entry(entry->list.prev, struct tsi148_dma_entry,
				  list);
		prev->descriptor.dnlau = cpu_to_be32(address_high);
		prev->descriptor.dnlal = cpu_to_be32(address_low);

	}

	return 0;

err_dma:
err_dest:
err_source:
err_align:
		kfree(entry);
err_mem:
	return retval;
}