Re: [PATCH for-next 1/2] RDMA/hns: Support query information of functions from FW

[liweihang <liweihang@huawei.com>]

On 2021/3/24 3:56, Jason Gunthorpe wrote:
> On Fri, Mar 12, 2021 at 05:48:26PM +0800, Weihang Li wrote:
> 
>> +static int hns_roce_query_func_info(struct hns_roce_dev *hr_dev)
>> +{
>> +	struct hns_roce_pf_func_info *resp;
>> +	struct hns_roce_cmq_desc desc;
>> +	int ret;
>> +
>> +	if (hr_dev->pci_dev->revision < PCI_REVISION_ID_HIP09)
>> +		return 0;
>> +
>> +	hns_roce_cmq_setup_basic_desc(&desc, HNS_ROCE_OPC_QUERY_FUNC_INFO,
>> +				      true);
>> +	ret = hns_roce_cmq_send(hr_dev, &desc, 1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	resp = (struct hns_roce_pf_func_info *)desc.data;
> 
> WTF is this cast?
> 
> struct hns_roce_cmq_desc {
>         __le16 opcode;
>         __le16 flag;
>         __le16 retval;
>         __le16 rsv;
>         __le32 data[6];
> };
> 
> Casting __le32 to a pointer is wrong
> 
> Jason
> 

Hi Jason

desc.data is the address of array 'data[6]', it is got from the firmware, we
cast it to 'struct hns_roce_pf_func_info *' to parse its contents. I think this
is a cast from '__le32 *' to 'struct hns_roce_pf_func_info *'.

Thanks
Weihang