dirty fix to merging

1 files changed, 295 insertions, 0 deletions

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
new file mode 100644
index 00000000..a8411232
--- /dev/null
+++ b/drivers/infiniband/core/umem.c
@@ -0,0 +1,295 @@
+/*
+ * Copyright (c) 2005 Topspin Communications.  All rights reserved.
+ * Copyright (c) 2005 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/sched.h>
+#include <linux/export.h>
+#include <linux/hugetlb.h>
+#include <linux/dma-attrs.h>
+#include <linux/slab.h>
+
+#include "uverbs.h"
+
+#define IB_UMEM_MAX_PAGE_CHUNK						\
+	((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) /	\
+	 ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] -	\
+	  (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
+
+static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
+{
+	struct ib_umem_chunk *chunk, *tmp;
+	int i;
+
+	list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
+		ib_dma_unmap_sg(dev, chunk->page_list,
+				chunk->nents, DMA_BIDIRECTIONAL);
+		for (i = 0; i < chunk->nents; ++i) {
+			struct page *page = sg_page(&chunk->page_list[i]);
+
+			if (umem->writable && dirty)
+				set_page_dirty_lock(page);
+			put_page(page);
+		}
+
+		kfree(chunk);
+	}
+}
+
+/**
+ * ib_umem_get - Pin and DMA map userspace memory.
+ * @context: userspace context to pin memory for
+ * @addr: userspace virtual address to start at
+ * @size: length of region to pin
+ * @access: IB_ACCESS_xxx flags for memory being pinned
+ * @dmasync: flush in-flight DMA when the memory region is written
+ */
+struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
+			    size_t size, int access, int dmasync)
+{
+	struct ib_umem *umem;
+	struct page **page_list;
+	struct vm_area_struct **vma_list;
+	struct ib_umem_chunk *chunk;
+	unsigned long locked;
+	unsigned long lock_limit;
+	unsigned long cur_base;
+	unsigned long npages;
+	int ret;
+	int off;
+	int i;
+	DEFINE_DMA_ATTRS(attrs);
+
+	if (dmasync)
+		dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
+
+	if (!can_do_mlock())
+		return ERR_PTR(-EPERM);
+
+	umem = kmalloc(sizeof *umem, GFP_KERNEL);
+	if (!umem)
+		return ERR_PTR(-ENOMEM);
+
+	umem->context   = context;
+	umem->length    = size;
+	umem->offset    = addr & ~PAGE_MASK;
+	umem->page_size = PAGE_SIZE;
+	/*
+	 * We ask for writable memory if any access flags other than
+	 * "remote read" are set.  "Local write" and "remote write"
+	 * obviously require write access.  "Remote atomic" can do
+	 * things like fetch and add, which will modify memory, and
+	 * "MW bind" can change permissions by binding a window.
+	 */
+	umem->writable  = !!(access & ~IB_ACCESS_REMOTE_READ);
+
+	/* We assume the memory is from hugetlb until proved otherwise */
+	umem->hugetlb   = 1;
+
+	INIT_LIST_HEAD(&umem->chunk_list);
+
+	page_list = (struct page **) __get_free_page(GFP_KERNEL);
+	if (!page_list) {
+		kfree(umem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/*
+	 * if we can't alloc the vma_list, it's not so bad;
+	 * just assume the memory is not hugetlb memory
+	 */
+	vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL);
+	if (!vma_list)
+		umem->hugetlb = 0;
+
+	npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
+
+	down_write(&current->mm->mmap_sem);
+
+	locked     = npages + current->mm->pinned_vm;
+	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	cur_base = addr & PAGE_MASK;
+
+	ret = 0;
+	while (npages) {
+		ret = get_user_pages(current, current->mm, cur_base,
+				     min_t(unsigned long, npages,
+					   PAGE_SIZE / sizeof (struct page *)),
+				     1, !umem->writable, page_list, vma_list);
+
+		if (ret < 0)
+			goto out;
+
+		cur_base += ret * PAGE_SIZE;
+		npages   -= ret;
+
+		off = 0;
+
+		while (ret) {
+			chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
+					min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
+					GFP_KERNEL);
+			if (!chunk) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
+			sg_init_table(chunk->page_list, chunk->nents);
+			for (i = 0; i < chunk->nents; ++i) {
+				if (vma_list &&
+				    !is_vm_hugetlb_page(vma_list[i + off]))
+					umem->hugetlb = 0;
+				sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
+			}
+
+			chunk->nmap = ib_dma_map_sg_attrs(context->device,
+							  &chunk->page_list[0],
+							  chunk->nents,
+							  DMA_BIDIRECTIONAL,
+							  &attrs);
+			if (chunk->nmap <= 0) {
+				for (i = 0; i < chunk->nents; ++i)
+					put_page(sg_page(&chunk->page_list[i]));
+				kfree(chunk);
+
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			ret -= chunk->nents;
+			off += chunk->nents;
+			list_add_tail(&chunk->list, &umem->chunk_list);
+		}
+
+		ret = 0;
+	}
+
+out:
+	if (ret < 0) {
+		__ib_umem_release(context->device, umem, 0);
+		kfree(umem);
+	} else
+		current->mm->pinned_vm = locked;
+
+	up_write(&current->mm->mmap_sem);
+	if (vma_list)
+		free_page((unsigned long) vma_list);
+	free_page((unsigned long) page_list);
+
+	return ret < 0 ? ERR_PTR(ret) : umem;
+}
+EXPORT_SYMBOL(ib_umem_get);
+
+static void ib_umem_account(struct work_struct *work)
+{
+	struct ib_umem *umem = container_of(work, struct ib_umem, work);
+
+	down_write(&umem->mm->mmap_sem);
+	umem->mm->pinned_vm -= umem->diff;
+	up_write(&umem->mm->mmap_sem);
+	mmput(umem->mm);
+	kfree(umem);
+}
+
+/**
+ * ib_umem_release - release memory pinned with ib_umem_get
+ * @umem: umem struct to release
+ */
+void ib_umem_release(struct ib_umem *umem)
+{
+	struct ib_ucontext *context = umem->context;
+	struct mm_struct *mm;
+	unsigned long diff;
+
+	__ib_umem_release(umem->context->device, umem, 1);
+
+	mm = get_task_mm(current);
+	if (!mm) {
+		kfree(umem);
+		return;
+	}
+
+	diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
+
+	/*
+	 * We may be called with the mm's mmap_sem already held.  This
+	 * can happen when a userspace munmap() is the call that drops
+	 * the last reference to our file and calls our release
+	 * method.  If there are memory regions to destroy, we'll end
+	 * up here and not be able to take the mmap_sem.  In that case
+	 * we defer the vm_locked accounting to the system workqueue.
+	 */
+	if (context->closing) {
+		if (!down_write_trylock(&mm->mmap_sem)) {
+			INIT_WORK(&umem->work, ib_umem_account);
+			umem->mm   = mm;
+			umem->diff = diff;
+
+			queue_work(ib_wq, &umem->work);
+			return;
+		}
+	} else
+		down_write(&mm->mmap_sem);
+
+	current->mm->pinned_vm -= diff;
+	up_write(&mm->mmap_sem);
+	mmput(mm);
+	kfree(umem);
+}
+EXPORT_SYMBOL(ib_umem_release);
+
+int ib_umem_page_count(struct ib_umem *umem)
+{
+	struct ib_umem_chunk *chunk;
+	int shift;
+	int i;
+	int n;
+
+	shift = ilog2(umem->page_size);
+
+	n = 0;
+	list_for_each_entry(chunk, &umem->chunk_list, list)
+		for (i = 0; i < chunk->nmap; ++i)
+			n += sg_dma_len(&chunk->page_list[i]) >> shift;
+
+	return n;
+}
+EXPORT_SYMBOL(ib_umem_page_count);