[PATCH v2 26/49] IB/hfi1: add user/kernel memory sharing hooks

Mike Marciniszyn
2015-06-15T13:28:18Z

drivers/infiniband/hw/hfi1/mmap.c | 192 +++++++++++++++++++++++++++++++++++++
1 file changed, 192 insertions(+)
create mode 100644 drivers/infiniband/hw/hfi1/mmap.c

diff --git a/drivers/infiniband/hw/hfi1/mmap.c b/drivers/infiniband/hw/hfi1/mmap.c
new file mode 100644
index 0000000..5173b1c
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/mmap.c
@@ -0,0 +1,192 @@
+/*
+ *
+ * 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
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * 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
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * 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/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <asm/pgtable.h>
+
+#include "verbs.h"
+
+/**
+ * hfi1_release_mmap_info - free mmap info structure
+ * @ref: a pointer to the kref within struct hfi1_mmap_info
+ */
+void hfi1_release_mmap_info(struct kref *ref)
+{
+ struct hfi1_mmap_info *ip =
+ container_of(ref, struct hfi1_mmap_info, ref);
+ struct hfi1_ibdev *dev = to_idev(ip->context->device);
+
+ spin_lock_irq(&dev->pending_lock);
+ list_del(&ip->pending_mmaps);
+ spin_unlock_irq(&dev->pending_lock);
+
+ vfree(ip->obj);
+ kfree(ip);
+}
+
+/*
+ * open and close keep track of how many times the CQ is mapped,
+ * to avoid releasing it.
+ */
+static void hfi1_vma_open(struct vm_area_struct *vma)
+{
+ struct hfi1_mmap_info *ip = vma->vm_private_data;
+
+ kref_get(&ip->ref);
+}
+
+static void hfi1_vma_close(struct vm_area_struct *vma)
+{
+ struct hfi1_mmap_info *ip = vma->vm_private_data;
+
+ kref_put(&ip->ref, hfi1_release_mmap_info);
+}
+
+static struct vm_operations_struct hfi1_vm_ops = {
+ .open = hfi1_vma_open,
+ .close = hfi1_vma_close,
+};
+
+/**
+ * hfi1_mmap - create a new mmap region
+ * @context: the IB user context of the process making the mmap() call
+ * @vma: the VMA to be initialized
+ * Return zero if the mmap is OK. Otherwise, return an errno.
+ */
+int hfi1_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
+{
+ struct hfi1_ibdev *dev = to_idev(context->device);
+ unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+ unsigned long size = vma->vm_end - vma->vm_start;
+ struct hfi1_mmap_info *ip, *pp;
+ int ret = -EINVAL;
+
+ /*
+ * Search the device's list of objects waiting for a mmap call.
+ * Normally, this list is very short since a call to create a
+ * CQ, QP, or SRQ is soon followed by a call to mmap().
+ */
+ spin_lock_irq(&dev->pending_lock);
+ list_for_each_entry_safe(ip, pp, &dev->pending_mmaps,
+ pending_mmaps) {
+ /* Only the creator is allowed to mmap the object */
+ if (context != ip->context || (__u64) offset != ip->offset)
+ continue;
+ /* Don't allow a mmap larger than the object. */
+ if (size > ip->size)
+ break;
+
+ list_del_init(&ip->pending_mmaps);
+ spin_unlock_irq(&dev->pending_lock);
+
+ ret = remap_vmalloc_range(vma, ip->obj, 0);
+ if (ret)
+ goto done;
+ vma->vm_ops = &hfi1_vm_ops;
+ vma->vm_private_data = ip;
+ hfi1_vma_open(vma);
+ goto done;
+ }
+ spin_unlock_irq(&dev->pending_lock);
+done:
+ return ret;
+}
+
+/*
+ * Allocate information for hfi1_mmap
+ */
+struct hfi1_mmap_info *hfi1_create_mmap_info(struct hfi1_ibdev *dev,
+ u32 size,
+ struct ib_ucontext *context,
+ void *obj) {
+ struct hfi1_mmap_info *ip;
+
+ ip = kmalloc(sizeof(*ip), GFP_KERNEL);
+ if (!ip)
+ goto bail;
+
+ size = PAGE_ALIGN(size);
+
+ spin_lock_irq(&dev->mmap_offset_lock);
+ if (dev->mmap_offset == 0)
+ dev->mmap_offset = PAGE_SIZE;
+ ip->offset = dev->mmap_offset;
+ dev->mmap_offset += size;
+ spin_unlock_irq(&dev->mmap_offset_lock);
+
+ INIT_LIST_HEAD(&ip->pending_mmaps);
+ ip->size = size;
+ ip->context = context;
+ ip->obj = obj;
+ kref_init(&ip->ref);
+
+bail:
+ return ip;
+}
+
+void hfi1_update_mmap_info(struct hfi1_ibdev *dev, struct hfi1_mmap_info *ip,
+ u32 size, void *obj)
+{
+ size = PAGE_ALIGN(size);
+
+ spin_lock_irq(&dev->mmap_offset_lock);
+ if (dev->mmap_offset == 0)
+ dev->mmap_offset = PAGE_SIZE;
+ ip->offset = dev->mmap_offset;
+ dev->mmap_offset += size;
+ spin_unlock_irq(&dev->mmap_offset_lock);
+
+ ip->size = size;
+ ip->obj = obj;