linux/net/9p/trans_common.h
Venkateswararao Jujjuri (JV) 022cae3655 [net/9p] Preparation and helper functions for zero copy
This patch prepares p9_fcall structure for zero copy. Added
fields send the payload buffer information to the transport layer.
In addition it adds a 'private' field for the transport layer to
store mapped/pinned page information so that it can be freed/unpinned
during req_done.

This patch also creates trans_common.[ch] to house helper functions.
It adds the following helper functions.

p9_release_req_pages - Release pages after the transaction.
p9_nr_pages - Return number of pages needed to accomodate the payload.
payload_gup - Translates user buffer into kernel pages.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-15 09:57:34 -05:00

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978 B
C

/*
* Copyright IBM Corporation, 2010
* Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
/**
* struct trans_rpage_info - To store mapped page information in PDU.
* @rp_alloc:Set if this structure is allocd, not a reuse unused space in pdu.
* @rp_nr_pages: Number of mapped pages
* @rp_data: Array of page pointers
*/
struct trans_rpage_info {
u8 rp_alloc;
int rp_nr_pages;
struct page *rp_data[0];
};
void p9_release_req_pages(struct trans_rpage_info *);
int p9_payload_gup(struct p9_req_t *, size_t *, int *, int, u8);
int p9_nr_pages(struct p9_req_t *);