127 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			127 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright(c) 2015-2017 Intel Corporation.
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|  *
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|  * This file is provided under a dual BSD/GPLv2 license.  When using or
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|  * redistributing this file, you may do so under either license.
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|  *
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|  * GPL LICENSE SUMMARY
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of version 2 of the GNU General Public License as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful, but
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|  * WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * General Public License for more details.
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|  *
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|  * BSD LICENSE
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  *
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|  *  - Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *  - Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in
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|  *    the documentation and/or other materials provided with the
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|  *    distribution.
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|  *  - Neither the name of Intel Corporation nor the names of its
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|  *    contributors may be used to endorse or promote products derived
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|  *    from this software without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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|  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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|  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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|  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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|  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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|  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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|  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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|  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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|  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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|  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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|  *
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|  */
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| 
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| #include <linux/mm.h>
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| #include <linux/sched/signal.h>
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| #include <linux/device.h>
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| #include <linux/module.h>
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| 
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| #include "hfi.h"
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| 
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| static unsigned long cache_size = 256;
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| module_param(cache_size, ulong, S_IRUGO | S_IWUSR);
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| MODULE_PARM_DESC(cache_size, "Send and receive side cache size limit (in MB)");
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| 
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| /*
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|  * Determine whether the caller can pin pages.
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|  *
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|  * This function should be used in the implementation of buffer caches.
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|  * The cache implementation should call this function prior to attempting
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|  * to pin buffer pages in order to determine whether they should do so.
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|  * The function computes cache limits based on the configured ulimit and
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|  * cache size. Use of this function is especially important for caches
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|  * which are not limited in any other way (e.g. by HW resources) and, thus,
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|  * could keeping caching buffers.
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|  *
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|  */
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| bool hfi1_can_pin_pages(struct hfi1_devdata *dd, struct mm_struct *mm,
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| 			u32 nlocked, u32 npages)
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| {
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| 	unsigned long ulimit = rlimit(RLIMIT_MEMLOCK), pinned, cache_limit,
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| 		size = (cache_size * (1UL << 20)); /* convert to bytes */
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| 	unsigned int usr_ctxts =
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| 			dd->num_rcv_contexts - dd->first_dyn_alloc_ctxt;
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| 	bool can_lock = capable(CAP_IPC_LOCK);
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| 
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| 	/*
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| 	 * Calculate per-cache size. The calculation below uses only a quarter
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| 	 * of the available per-context limit. This leaves space for other
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| 	 * pinning. Should we worry about shared ctxts?
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| 	 */
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| 	cache_limit = (ulimit / usr_ctxts) / 4;
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| 
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| 	/* If ulimit isn't set to "unlimited" and is smaller than cache_size. */
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| 	if (ulimit != (-1UL) && size > cache_limit)
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| 		size = cache_limit;
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| 
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| 	/* Convert to number of pages */
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| 	size = DIV_ROUND_UP(size, PAGE_SIZE);
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| 
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| 	pinned = atomic64_read(&mm->pinned_vm);
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| 
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| 	/* First, check the absolute limit against all pinned pages. */
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| 	if (pinned + npages >= ulimit && !can_lock)
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| 		return false;
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| 
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| 	return ((nlocked + npages) <= size) || can_lock;
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| }
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| 
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| int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t npages,
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| 			    bool writable, struct page **pages)
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| {
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| 	int ret;
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| 	unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);
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| 
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| 	ret = pin_user_pages_fast(vaddr, npages, gup_flags, pages);
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| 	if (ret < 0)
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| 		return ret;
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| 
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| 	atomic64_add(ret, &mm->pinned_vm);
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| 
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| 	return ret;
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| }
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| 
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| void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
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| 			     size_t npages, bool dirty)
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| {
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| 	unpin_user_pages_dirty_lock(p, npages, dirty);
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| 
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| 	if (mm) { /* during close after signal, mm can be NULL */
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| 		atomic64_sub(npages, &mm->pinned_vm);
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| 	}
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| }
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