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// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
/*
* Copyright(c) 2015-2017 Intel Corporation.
*/
#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 int usr_ctxts =
dd->num_rcv_contexts - dd->first_dyn_alloc_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);
pinned = atomic64_read(&mm->pinned_vm);
/* 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;
unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0);
ret = pin_user_pages_fast(vaddr, npages, gup_flags, pages);
if (ret < 0)
return ret;
atomic64_add(ret, &mm->pinned_vm);
return ret;
}
void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
size_t npages, bool dirty)
{
unpin_user_pages_dirty_lock(p, npages, dirty);
if (mm) { /* during close after signal, mm can be NULL */
atomic64_sub(npages, &mm->pinned_vm);
}
}
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