/* * Copyright (c) 2006 Oracle. 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 #include #include #include #include "rds.h" struct rds_page_remainder { struct page *r_page; unsigned long r_offset; }; static DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_page_remainder, rds_page_remainders); /* * returns 0 on success or -errno on failure. * * We don't have to worry about flush_dcache_page() as this only works * with private pages. If, say, we were to do directed receive to pinned * user pages we'd have to worry more about cache coherence. (Though * the flush_dcache_page() in get_user_pages() would probably be enough). */ int rds_page_copy_user(struct page *page, unsigned long offset, void __user *ptr, unsigned long bytes, int to_user) { unsigned long ret; void *addr; addr = kmap(page); if (to_user) { rds_stats_add(s_copy_to_user, bytes); ret = copy_to_user(ptr, addr + offset, bytes); } else { rds_stats_add(s_copy_from_user, bytes); ret = copy_from_user(addr + offset, ptr, bytes); } kunmap(page); return ret ? -EFAULT : 0; } EXPORT_SYMBOL_GPL(rds_page_copy_user); /** * rds_page_remainder_alloc - build up regions of a message. * * @scat: Scatter list for message * @bytes: the number of bytes needed. * @gfp: the waiting behaviour of the allocation * * @gfp is always ored with __GFP_HIGHMEM. Callers must be prepared to * kmap the pages, etc. * * If @bytes is at least a full page then this just returns a page from * alloc_page(). * * If @bytes is a partial page then this stores the unused region of the * page in a per-cpu structure. Future partial-page allocations may be * satisfied from that cached region. This lets us waste less memory on * small allocations with minimal complexity. It works because the transmit * path passes read-only page regions down to devices. They hold a page * reference until they are done with the region. */ int rds_page_remainder_alloc(struct scatterlist *scat, unsigned long bytes, gfp_t gfp) { struct rds_page_remainder *rem; unsigned long flags; struct page *page; int ret; gfp |= __GFP_HIGHMEM; /* jump straight to allocation if we're trying for a huge page */ if (bytes >= PAGE_SIZE) { page = alloc_page(gfp); if (!page) { ret = -ENOMEM; } else { sg_set_page(scat, page, PAGE_SIZE, 0); ret = 0; } goto out; } rem = &per_cpu(rds_page_remainders, get_cpu()); local_irq_save(flags); while (1) { /* avoid a tiny region getting stuck by tossing it */ if (rem->r_page && bytes > (PAGE_SIZE - rem->r_offset)) { rds_stats_inc(s_page_remainder_miss); __free_page(rem->r_page); rem->r_page = NULL; } /* hand out a fragment from the cached page */ if (rem->r_page && bytes <= (PAGE_SIZE - rem->r_offset)) { sg_set_page(scat, rem->r_page, bytes, rem->r_offset); get_page(sg_page(scat)); if (rem->r_offset != 0) rds_stats_inc(s_page_remainder_hit); rem->r_offset += ALIGN(bytes, 8); if (rem->r_offset >= PAGE_SIZE) { __free_page(rem->r_page); rem->r_page = NULL; } ret = 0; break; } /* alloc if there is nothing for us to use */ local_irq_restore(flags); put_cpu(); page = alloc_page(gfp); rem = &per_cpu(rds_page_remainders, get_cpu()); local_irq_save(flags); if (!page) { ret = -ENOMEM; break; } /* did someone race to fill the remainder before us? */ if (rem->r_page) { __free_page(page); continue; } /* otherwise install our page and loop around to alloc */ rem->r_page = page; rem->r_offset = 0; } local_irq_restore(flags); put_cpu(); out: rdsdebug("bytes %lu ret %d %p %u %u\n", bytes, ret, ret ? NULL : sg_page(scat), ret ? 0 : scat->offset, ret ? 0 : scat->length); return ret; } EXPORT_SYMBOL_GPL(rds_page_remainder_alloc); void rds_page_exit(void) { unsigned int cpu; for_each_possible_cpu(cpu) { struct rds_page_remainder *rem; rem = &per_cpu(rds_page_remainders, cpu); rdsdebug("cpu %u\n", cpu); if (rem->r_page) __free_page(rem->r_page); rem->r_page = NULL; } } ss='decoration'>HEADmaster
Pull documentation update from Jonathan Corbet: "These are the documentation changes for 4.10. It's another busy cycle for the docs tree, as the sphinx conversion continues. Highlights include: - Further work on PDF output, which remains a bit of a pain but should be more solid now. - Five more DocBook template files converted to Sphinx. Only 27 to go... Lots of plain-text files have also been converted and integrated. - Images in binary formats have been replaced with more source-friendly versions. - Various bits of organizational work, including the renaming of various files discussed at the kernel summit. - New documentation for the device_link mechanism. ... and, of course, lots of typo fixes and small updates" * tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits) dma-buf: Extract dma-buf.rst Update Documentation/00-INDEX docs: 00-INDEX: document directories/files with no docs docs: 00-INDEX: remove non-existing entries docs: 00-INDEX: add missing entries for documentation files/dirs docs: 00-INDEX: consolidate process/ and admin-guide/ description scripts: add a script to check if Documentation/00-INDEX is sane Docs: change sh -> awk in REPORTING-BUGS Documentation/core-api/device_link: Add initial documentation core-api: remove an unexpected unident ppc/idle: Add documentation for powersave=off Doc: Correct typo, "Introdution" => "Introduction" Documentation/atomic_ops.txt: convert to ReST markup Documentation/local_ops.txt: convert to ReST markup Documentation/assoc_array.txt: convert to ReST markup docs-rst: parse-headers.pl: cleanup the documentation docs-rst: fix media cleandocs target docs-rst: media/Makefile: reorganize the rules docs-rst: media: build SVG from graphviz files docs-rst: replace bayer.png by a SVG image ...
Diffstat (limited to 'lib/mpi/mpi-inline.h')