Re: [PATCH v2 2/2] drivers: remoteproc: Add C906L controller for Sophgo CV1800B SoC

[Krzysztof Kozlowski <krzk@kernel.org>]

On 30/07/2025 11:27, Junhui Liu wrote:
> On 30/07/2025 08:46, Krzysztof Kozlowski wrote:
>> On 28/07/2025 13:03, Junhui Liu wrote:
>>> +
>>> +static int cv1800b_c906l_mem_alloc(struct rproc *rproc,
>>> +				   struct rproc_mem_entry *mem)
>>> +{
>>> +	void __iomem *va;
>>> +
>>> +	va = ioremap_wc(mem->dma, mem->len);
>>> +	if (!va)
>>> +		return -ENOMEM;
>>> +
>>> +	/* Update memory entry va */
>>> +	mem->va = (void *)va;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int cv1800b_c906l_mem_release(struct rproc *rproc,
>>> +				     struct rproc_mem_entry *mem)
>>> +{
>>> +	iounmap((void __iomem *)mem->va);
>>> +	return 0;
>>> +}
>>> +
>>> +static int cv1800b_c906l_add_carveout(struct rproc *rproc)
>>> +{
>>> +	struct device *dev = rproc->dev.parent;
>>> +	struct device_node *np = dev->of_node;
>>> +	struct of_phandle_iterator it;
>>> +	struct rproc_mem_entry *mem;
>>> +	struct reserved_mem *rmem;
>>> +	int i = 0;
>>> +
>>> +	/* Register associated reserved memory regions */
>>> +	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
>>> +	while (of_phandle_iterator_next(&it) == 0) {
>>> +		rmem = of_reserved_mem_lookup(it.node);
>>> +		if (!rmem) {
>>> +			of_node_put(it.node);
>>> +			return -EINVAL;
>>> +		}
>>> +
>>> +		if (!strcmp(it.node->name, "vdev0buffer")) {
>>
>> Why are you adding undocumented ABI? And so hidden, not even using
>> standard OF API!
>>
>> How does this behaves when I change your DTS to call it
>> "whateverbuffer"? Does it work? Obviously not.
>>
>> No, stop doing that.
> 
> Yes, you're right. I will consider introducing a "memory-region-names"
> property in the bindings, instead of relying on the node labels directly.


You don't need it. First, you use some old code as template, but you
should look how or re-use Rob's code rewriting this completely.

Second, list has strict order, so you know exactly where the vdev0
buffer is. It cannot be on any other position of the list.

This is why you define the ABI. Use then the ABI.


Best regards,
Krzysztof