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-rw-r--r--drivers/infiniband/hw/hfi1/user_pages.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c
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+++ b/drivers/infiniband/hw/hfi1/user_pages.c
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+/*
+ * Copyright(c) 2015-2017 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 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);
+
+ 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);
+ }
+}