85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
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// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
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/*
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* Copyright(c) 2015-2017 Intel Corporation.
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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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#include "hfi.h"
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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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* 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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* 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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/* 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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/* Convert to number of pages */
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size = DIV_ROUND_UP(size, PAGE_SIZE);
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pinned = atomic64_read(&mm->pinned_vm);
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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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return ((nlocked + npages) <= size) || can_lock;
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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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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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atomic64_add(ret, &mm->pinned_vm);
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return ret;
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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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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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