static int ar_context_init()

in ohci.c [969:1020]

• 44 lines of code
• 7 McCabe index (conditional complexity)

static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
			   unsigned int descriptors_offset, u32 regs)
{
	struct device *dev = ohci->card.device;
	unsigned int i;
	dma_addr_t dma_addr;
	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
	struct descriptor *d;

	ctx->regs        = regs;
	ctx->ohci        = ohci;
	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);

	for (i = 0; i < AR_BUFFERS; i++) {
		ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr,
						DMA_FROM_DEVICE, GFP_KERNEL);
		if (!ctx->pages[i])
			goto out_of_memory;
		set_page_private(ctx->pages[i], dma_addr);
		dma_sync_single_for_device(dev, dma_addr, PAGE_SIZE,
					   DMA_FROM_DEVICE);
	}

	for (i = 0; i < AR_BUFFERS; i++)
		pages[i]              = ctx->pages[i];
	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
		pages[AR_BUFFERS + i] = ctx->pages[i];
	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
	if (!ctx->buffer)
		goto out_of_memory;

	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;

	for (i = 0; i < AR_BUFFERS; i++) {
		d = &ctx->descriptors[i];
		d->req_count      = cpu_to_le16(PAGE_SIZE);
		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
						DESCRIPTOR_STATUS |
						DESCRIPTOR_BRANCH_ALWAYS);
		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
			ar_next_buffer_index(i) * sizeof(struct descriptor));
	}

	return 0;

out_of_memory:
	ar_context_release(ctx);

	return -ENOMEM;
}