static int k3_r5_reserved_mem_init()

in ti_k3_r5_remoteproc.c [862:952]

• 70 lines of code
• 10 McCabe index (conditional complexity)

static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
{
	struct device *dev = kproc->dev;
	struct device_node *np = dev_of_node(dev);
	struct device_node *rmem_np;
	struct reserved_mem *rmem;
	int num_rmems;
	int ret, i;

	num_rmems = of_property_count_elems_of_size(np, "memory-region",
						    sizeof(phandle));
	if (num_rmems <= 0) {
		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
			num_rmems);
		return -EINVAL;
	}
	if (num_rmems < 2) {
		dev_err(dev, "device needs at least two memory regions to be defined, num = %d\n",
			num_rmems);
		return -EINVAL;
	}

	/* use reserved memory region 0 for vring DMA allocations */
	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
	if (ret) {
		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
			ret);
		return ret;
	}

	num_rmems--;
	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
	if (!kproc->rmem) {
		ret = -ENOMEM;
		goto release_rmem;
	}

	/* use remaining reserved memory regions for static carveouts */
	for (i = 0; i < num_rmems; i++) {
		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
		if (!rmem_np) {
			ret = -EINVAL;
			goto unmap_rmem;
		}

		rmem = of_reserved_mem_lookup(rmem_np);
		if (!rmem) {
			of_node_put(rmem_np);
			ret = -EINVAL;
			goto unmap_rmem;
		}
		of_node_put(rmem_np);

		kproc->rmem[i].bus_addr = rmem->base;
		/*
		 * R5Fs do not have an MMU, but have a Region Address Translator
		 * (RAT) module that provides a fixed entry translation between
		 * the 32-bit processor addresses to 64-bit bus addresses. The
		 * RAT is programmable only by the R5F cores. Support for RAT
		 * is currently not supported, so 64-bit address regions are not
		 * supported. The absence of MMUs implies that the R5F device
		 * addresses/supported memory regions are restricted to 32-bit
		 * bus addresses, and are identical
		 */
		kproc->rmem[i].dev_addr = (u32)rmem->base;
		kproc->rmem[i].size = rmem->size;
		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
		if (!kproc->rmem[i].cpu_addr) {
			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
				i + 1, &rmem->base, &rmem->size);
			ret = -ENOMEM;
			goto unmap_rmem;
		}

		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
			i + 1, &kproc->rmem[i].bus_addr,
			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
			kproc->rmem[i].dev_addr);
	}
	kproc->num_rmems = num_rmems;

	return 0;

unmap_rmem:
	for (i--; i >= 0; i--)
		iounmap(kproc->rmem[i].cpu_addr);
	kfree(kproc->rmem);
release_rmem:
	of_reserved_mem_device_release(dev);
	return ret;
}