These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / staging / rdma / hfi1 / mmap.c
diff --git a/kernel/drivers/staging/rdma/hfi1/mmap.c b/kernel/drivers/staging/rdma/hfi1/mmap.c
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+/*
+ *
+ * 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;
+}