linux/include/rdma/ib_umem.h
Haggai Eran c5d76f130b IB/core: Add umem function to read data from user-space
In some drivers there's a need to read data from a user space area
that was pinned using ib_umem when running from a different process
context.

The ib_umem_copy_from function allows reading data from the physical
pages pinned in the ib_umem struct.

Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-12-15 18:13:35 -08:00

105 lines
3.3 KiB
C

/*
* Copyright (c) 2007 Cisco Systems. 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.
*/
#ifndef IB_UMEM_H
#define IB_UMEM_H
#include <linux/list.h>
#include <linux/scatterlist.h>
#include <linux/workqueue.h>
struct ib_ucontext;
struct ib_umem {
struct ib_ucontext *context;
size_t length;
unsigned long address;
int page_size;
int writable;
int hugetlb;
struct work_struct work;
struct pid *pid;
struct mm_struct *mm;
unsigned long diff;
struct sg_table sg_head;
int nmap;
int npages;
};
/* Returns the offset of the umem start relative to the first page. */
static inline int ib_umem_offset(struct ib_umem *umem)
{
return umem->address & ((unsigned long)umem->page_size - 1);
}
/* Returns the first page of an ODP umem. */
static inline unsigned long ib_umem_start(struct ib_umem *umem)
{
return umem->address - ib_umem_offset(umem);
}
/* Returns the address of the page after the last one of an ODP umem. */
static inline unsigned long ib_umem_end(struct ib_umem *umem)
{
return PAGE_ALIGN(umem->address + umem->length);
}
static inline size_t ib_umem_num_pages(struct ib_umem *umem)
{
return (ib_umem_end(umem) - ib_umem_start(umem)) >> PAGE_SHIFT;
}
#ifdef CONFIG_INFINIBAND_USER_MEM
struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
size_t size, int access, int dmasync);
void ib_umem_release(struct ib_umem *umem);
int ib_umem_page_count(struct ib_umem *umem);
int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
size_t length);
#else /* CONFIG_INFINIBAND_USER_MEM */
#include <linux/err.h>
static inline struct ib_umem *ib_umem_get(struct ib_ucontext *context,
unsigned long addr, size_t size,
int access, int dmasync) {
return ERR_PTR(-EINVAL);
}
static inline void ib_umem_release(struct ib_umem *umem) { }
static inline int ib_umem_page_count(struct ib_umem *umem) { return 0; }
#endif /* CONFIG_INFINIBAND_USER_MEM */
#endif /* IB_UMEM_H */