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/*
* Copyright(c) 2015, 2016 Intel Corporation.
*
* 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
*
* 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
*
* 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/sched/signal.h>
#include <linux/device.h>
#include <linux/module.h>
#include "hfi.h"
static unsigned long cache_size = 256;
module_param(cache_size, ulong, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(cache_size, "Send and receive side cache size limit (in MB)");
/*
* Determine whether the caller can pin pages.
*
* This function should be used in the implementation of buffer caches.
* The cache implementation should call this function prior to attempting
* to pin buffer pages in order to determine whether they should do so.
* The function computes cache limits based on the configured ulimit and
* cache size. Use of this function is especially important for caches
* which are not limited in any other way (e.g. by HW resources) and, thus,
* could keeping caching buffers.
*
*/
bool hfi1_can_pin_pages(struct hfi1_devdata *dd, struct mm_struct *mm,
u32 nlocked, u32 npages)
{
unsigned long ulimit = rlimit(RLIMIT_MEMLOCK), pinned, cache_limit,
size = (cache_size * (1UL << 20)); /* convert to bytes */
unsigned usr_ctxts = dd->num_rcv_contexts - dd->first_user_ctxt;
bool can_lock = capable(CAP_IPC_LOCK);
/*
* Calculate per-cache size. The calculation below uses only a quarter
* of the available per-context limit. This leaves space for other
* pinning. Should we worry about shared ctxts?
*/
cache_limit = (ulimit / usr_ctxts) / 4;
/* If ulimit isn't set to "unlimited" and is smaller than cache_size. */
if (ulimit != (-1UL) && size > cache_limit)
size = cache_limit;
/* Convert to number of pages */
size = DIV_ROUND_UP(size, PAGE_SIZE);
down_read(&mm->mmap_sem);
pinned = mm->pinned_vm;
up_read(&mm->mmap_sem);
/* First, check the absolute limit against all pinned pages. */
if (pinned + npages >= ulimit && !can_lock)
return false;
return ((nlocked + npages) <= size) || can_lock;
}
int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t npages,
bool writable, struct page **pages)
{
int ret;
ret = get_user_pages_fast(vaddr, npages, writable, pages);
if (ret < 0)
return ret;
down_write(&mm->mmap_sem);
mm->pinned_vm += ret;
up_write(&mm->mmap_sem);
return ret;
}
void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
size_t npages, bool dirty)
{
size_t i;
for (i = 0; i < npages; i++) {
if (dirty)
set_page_dirty_lock(p[i]);
put_page(p[i]);
}
if (mm) { /* during close after signal, mm can be NULL */
down_write(&mm->mmap_sem);
mm->pinned_vm -= npages;
up_write(&mm->mmap_sem);
}
}
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