linux/drivers/infiniband/core/umem.c

/*
 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Cisco Systems.  All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2020 Intel Corporation. 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/dma-mapping.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/count_zeros.h>
#include <rdma/ib_umem_odp.h>

#include "uverbs.h"

static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{ … }

/**
 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR
 *
 * @umem: umem struct
 * @pgsz_bitmap: bitmap of HW supported page sizes
 * @virt: IOVA
 *
 * This helper is intended for HW that support multiple page
 * sizes but can do only a single page size in an MR.
 *
 * Returns 0 if the umem requires page sizes not supported by
 * the driver to be mapped. Drivers always supporting PAGE_SIZE
 * or smaller will never see a 0 result.
 */
unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
				     unsigned long pgsz_bitmap,
				     unsigned long virt)
{ … }
EXPORT_SYMBOL(…);

/**
 * ib_umem_get - Pin and DMA map userspace memory.
 *
 * @device: IB device to connect UMEM
 * @addr: userspace virtual address to start at
 * @size: length of region to pin
 * @access: IB_ACCESS_xxx flags for memory being pinned
 */
struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
			    size_t size, int access)
{ … }
EXPORT_SYMBOL(…);

/**
 * ib_umem_release - release memory pinned with ib_umem_get
 * @umem: umem struct to release
 */
void ib_umem_release(struct ib_umem *umem)
{ … }
EXPORT_SYMBOL(…);

/*
 * Copy from the given ib_umem's pages to the given buffer.
 *
 * umem - the umem to copy from
 * offset - offset to start copying from
 * dst - destination buffer
 * length - buffer length
 *
 * Returns 0 on success, or an error code.
 */
int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
		      size_t length)
{ … }
EXPORT_SYMBOL(…);