[PATCH v9 12/27] gunyah: rsc_mgr: Add RPC for sharing memory

[Srivatsa Vaddagiri]

* Elliot Berman <quic_eberman at quicinc.com> [2023-01-20 14:46:11]:

> +static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_mem_parcel *p)
> +{
> +	size_t msg_size = 0, initial_n_mem_entries = p->n_mem_entries;
> +	void *msg;
> +	__le32 *resp;
> +	struct gh_mem_share_req_header *req_header;
> +	struct gh_mem_share_req_acl_section *acl_section;
> +	struct gh_mem_share_req_mem_section *mem_section;
> +	u32 *mem_attr_section;
> +	size_t resp_size;
> +	int ret;
> +
> +	if (!p->acl_entries || !p->n_acl_entries || !p->mem_entries || !p->n_mem_entries ||
> +	    p->n_acl_entries > U8_MAX || p->mem_handle != GH_MEM_HANDLE_INVAL)
> +		return -EINVAL;
> +
> +	if (initial_n_mem_entries > GH_RM_MAX_MEM_ENTRIES)
> +		initial_n_mem_entries = GH_RM_MAX_MEM_ENTRIES;
> +
> +	/* The format of the message goes:
> +	 * request header
> +	 * ACL entries (which VMs get what kind of access to this memory parcel)
> +	 * Memory entries (list of memory regions to share)
> +	 * Memory attributes (currently unused, we'll hard-code the size to 0)
> +	 */
> +	msg_size += sizeof(struct gh_mem_share_req_header);
> +	msg_size += offsetof(struct gh_mem_share_req_acl_section, entries[p->n_acl_entries]);
> +	msg_size += offsetof(struct gh_mem_share_req_mem_section, entries[initial_n_mem_entries]);
> +	msg_size += sizeof(u32); /* for memory attributes, currently unused */
> +
> +	msg = kzalloc(msg_size, GFP_KERNEL);
> +	if (!msg)
> +		return -ENOMEM;
> +
> +	ret = gh_rm_platform_pre_mem_share(rm, p);

Hmm ..I think gh_rm_platform_pre_mem_share() is not yet defined as of this
patch, so you probably want this in a later patch.

> +	if (ret) {
> +		kfree(msg);
> +		return ret;
> +	}
> +