linux/drivers/infiniband/hw/qib/qib_user_pages.c

/*
 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/mm.h>
#include <linux/sched/signal.h>
#include <linux/device.h>

#include "qib.h"

static void __qib_release_user_pages(struct page **p, size_t num_pages,
				     int dirty)
{ … }

/*
 * qib_map_page - a safety wrapper around pci_map_page()
 *
 * A dma_addr of all 0's is interpreted by the chip as "disabled".
 * Unfortunately, it can also be a valid dma_addr returned on some
 * architectures.
 *
 * The powerpc iommu assigns dma_addrs in ascending order, so we don't
 * have to bother with retries or mapping a dummy page to insure we
 * don't just get the same mapping again.
 *
 * I'm sure we won't be so lucky with other iommu's, so FIXME.
 */
int qib_map_page(struct pci_dev *hwdev, struct page *page, dma_addr_t *daddr)
{ … }

/**
 * qib_get_user_pages - lock user pages into memory
 * @start_page: the start page
 * @num_pages: the number of pages
 * @p: the output page structures
 *
 * This function takes a given start page (page aligned user virtual
 * address) and pins it and the following specified number of pages.  For
 * now, num_pages is always 1, but that will probably change at some point
 * (because caller is doing expected sends on a single virtually contiguous
 * buffer, so we can do all pages at once).
 */
int qib_get_user_pages(unsigned long start_page, size_t num_pages,
		       struct page **p)
{ … }

void qib_release_user_pages(struct page **p, size_t num_pages)
{ … }