1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c
new file mode 100644
index 000000000..36aaedc65
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/user_pages.c
@@ -0,0 +1,103 @@
+// 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_pages;
+	unsigned long cache_limit_pages;
+	unsigned int usr_ctxts;
+
+	/*
+	 * Perform RLIMIT_MEMLOCK based checks unless CAP_IPC_LOCK is present.
+	 */
+	if (!capable(CAP_IPC_LOCK)) {
+		ulimit_pages =
+			DIV_ROUND_DOWN_ULL(rlimit(RLIMIT_MEMLOCK), PAGE_SIZE);
+
+		/*
+		 * Pinning these pages would exceed this process's locked memory
+		 * limit.
+		 */
+		if (atomic64_read(&mm->pinned_vm) + npages > ulimit_pages)
+			return false;
+
+		/*
+		 * Only allow 1/4 of the user's RLIMIT_MEMLOCK to be used for HFI
+		 * caches.  This fraction is then equally distributed among all
+		 * existing user contexts.  Note that if RLIMIT_MEMLOCK is
+		 * 'unlimited' (-1), the value of this limit will be > 2^42 pages
+		 * (2^64 / 2^12 / 2^8 / 2^2).
+		 *
+		 * The effectiveness of this check may be reduced if I/O occurs on
+		 * some user contexts before all user contexts are created.  This
+		 * check assumes that this process is the only one using this
+		 * context (e.g., the corresponding fd was not passed to another
+		 * process for concurrent access) as there is no per-context,
+		 * per-process tracking of pinned pages.  It also assumes that each
+		 * user context has only one cache to limit.
+		 */
+		usr_ctxts = dd->num_rcv_contexts - dd->first_dyn_alloc_ctxt;
+		if (nlocked + npages > (ulimit_pages / usr_ctxts / 4))
+			return false;
+	}
+
+	/*
+	 * Pinning these pages would exceed the size limit for this cache.
+	 */
+	cache_limit_pages = cache_size * (1024 * 1024) / PAGE_SIZE;
+	if (nlocked + npages > cache_limit_pages)
+		return false;
+
+	return true;
+}
+
+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);
+	}
+}