diff options
Diffstat (limited to 'drivers/staging/rdma/hfi1/user_pages.c')
| -rw-r--r-- | drivers/staging/rdma/hfi1/user_pages.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/staging/rdma/hfi1/user_pages.c b/drivers/staging/rdma/hfi1/user_pages.c new file mode 100644 index 000000000000..9071afbd7bf4 --- /dev/null +++ b/drivers/staging/rdma/hfi1/user_pages.c @@ -0,0 +1,156 @@ +/* + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2015 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * Copyright(c) 2015 Intel Corporation. + * + * 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. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <linux/mm.h> +#include <linux/device.h> + +#include "hfi.h" + +static void __hfi1_release_user_pages(struct page **p, size_t num_pages, + int dirty) +{ + size_t i; + + for (i = 0; i < num_pages; i++) { + if (dirty) + set_page_dirty_lock(p[i]); + put_page(p[i]); + } +} + +/* + * Call with current->mm->mmap_sem held. + */ +static int __hfi1_get_user_pages(unsigned long start_page, size_t num_pages, + struct page **p) +{ + unsigned long lock_limit; + size_t got; + int ret; + + lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) { + ret = -ENOMEM; + goto bail; + } + + for (got = 0; got < num_pages; got += ret) { + ret = get_user_pages(current, current->mm, + start_page + got * PAGE_SIZE, + num_pages - got, 1, 1, + p + got, NULL); + if (ret < 0) + goto bail_release; + } + + current->mm->pinned_vm += num_pages; + + ret = 0; + goto bail; + +bail_release: + __hfi1_release_user_pages(p, got, 0); +bail: + return ret; +} + +/** + * hfi1_map_page - a safety wrapper around pci_map_page() + * + */ +dma_addr_t hfi1_map_page(struct pci_dev *hwdev, struct page *page, + unsigned long offset, size_t size, int direction) +{ + dma_addr_t phys; + + phys = pci_map_page(hwdev, page, offset, size, direction); + + return phys; +} + +/** + * hfi1_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 hfi1_get_user_pages(unsigned long start_page, size_t num_pages, + struct page **p) +{ + int ret; + + down_write(¤t->mm->mmap_sem); + + ret = __hfi1_get_user_pages(start_page, num_pages, p); + + up_write(¤t->mm->mmap_sem); + + return ret; +} + +void hfi1_release_user_pages(struct page **p, size_t num_pages) +{ + if (current->mm) /* during close after signal, mm can be NULL */ + down_write(¤t->mm->mmap_sem); + + __hfi1_release_user_pages(p, num_pages, 1); + + if (current->mm) { + current->mm->pinned_vm -= num_pages; + up_write(¤t->mm->mmap_sem); + } +} |