Subject: Re: [Xen-devel] efi_enabled(EFI_PARAVIRT) use

From: Matt Fleming <[email-masked]>
Date: Wed, 4 May 2016 12:36:13 +0100

On Tue, 03 May, at 09:45:22AM, Shannon Zhao wrote:
> > +static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
> > +				       int depth, void *data)
> > +{
> > +	struct param_info *info = data;
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
> > +
> > +		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
> > +			info->missing = dt_params[i].params[0].name;
> > +			continue;
> > +		}
> > +
> So here it needs to check whether the node is /hypervisor. If so, get
> the subnode "uefi". Like below:
> if (strcmp(uname, "hypervisor") == 0) {
> 	offset = of_get_flat_dt_subnode_by_name(node, "uefi");
> 	if (offset < 0)
> 		return 0;
> 	node = offset;
> }

Urgh, right.

How about giving dt_params a const char *subnode field and doing,

	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
		const char *subnode = dt_params[i].sub_node;

		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
			info->missing = dt_params[i].params[0].name;
			continue;
		}

		if (subnode) {
			offset = of_get_flat_dt_subnode_by_name(node, subnode);
			if (offset < 0)
				return 0;
			node = offset;
		}

	...