1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
new file mode 100644
index 000000000..a41792dba
--- /dev/null
+++ b/drivers/infiniband/core/umem.c
@@ -0,0 +1,349 @@
+/*
+ * 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/signal.h>
+#include <linux/sched/mm.h>
+#include <linux/export.h>
+#include <linux/hugetlb.h>
+#include <linux/slab.h>
+#include <rdma/ib_umem_odp.h>
+
+#include "uverbs.h"
+
+
+static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
+{
+	struct scatterlist *sg;
+	struct page *page;
+	int i;
+
+	if (umem->nmap > 0)
+		ib_dma_unmap_sg(dev, umem->sg_head.sgl,
+				umem->npages,
+				DMA_BIDIRECTIONAL);
+
+	for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) {
+
+		page = sg_page(sg);
+		if (!PageDirty(page) && umem->writable && dirty)
+			set_page_dirty_lock(page);
+		put_page(page);
+	}
+
+	sg_free_table(&umem->sg_head);
+}
+
+/**
+ * ib_umem_get - Pin and DMA map userspace memory.
+ *
+ * If access flags indicate ODP memory, avoid pinning. Instead, stores
+ * the mm for future page fault handling in conjunction with MMU notifiers.
+ *
+ * @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;
+	unsigned long lock_limit;
+	unsigned long cur_base;
+	unsigned long npages;
+	int ret;
+	int i;
+	unsigned long dma_attrs = 0;
+	struct scatterlist *sg, *sg_list_start;
+	unsigned int gup_flags = FOLL_WRITE;
+
+	if (dmasync)
+		dma_attrs |= DMA_ATTR_WRITE_BARRIER;
+
+	/*
+	 * If the combination of the addr and size requested for this memory
+	 * region causes an integer overflow, return error.
+	 */
+	if (((addr + size) < addr) ||
+	    PAGE_ALIGN(addr + size) < (addr + size))
+		return ERR_PTR(-EINVAL);
+
+	if (!can_do_mlock())
+		return ERR_PTR(-EPERM);
+
+	umem = kzalloc(sizeof *umem, GFP_KERNEL);
+	if (!umem)
+		return ERR_PTR(-ENOMEM);
+
+	umem->context    = context;
+	umem->length     = size;
+	umem->address    = addr;
+	umem->page_shift = PAGE_SHIFT;
+	umem->writable   = ib_access_writable(access);
+
+	if (access & IB_ACCESS_ON_DEMAND) {
+		ret = ib_umem_odp_get(context, umem, access);
+		if (ret)
+			goto umem_kfree;
+		return umem;
+	}
+
+	umem->odp_data = NULL;
+
+	/* We assume the memory is from hugetlb until proved otherwise */
+	umem->hugetlb   = 1;
+
+	page_list = (struct page **) __get_free_page(GFP_KERNEL);
+	if (!page_list) {
+		ret = -ENOMEM;
+		goto umem_kfree;
+	}
+
+	/*
+	 * 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 = ib_umem_num_pages(umem);
+
+	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+	down_write(&current->mm->mmap_sem);
+	current->mm->pinned_vm += npages;
+	if ((current->mm->pinned_vm > lock_limit) && !capable(CAP_IPC_LOCK)) {
+		up_write(&current->mm->mmap_sem);
+		ret = -ENOMEM;
+		goto vma;
+	}
+	up_write(&current->mm->mmap_sem);
+
+	cur_base = addr & PAGE_MASK;
+
+	if (npages == 0 || npages > UINT_MAX) {
+		ret = -EINVAL;
+		goto vma;
+	}
+
+	ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL);
+	if (ret)
+		goto vma;
+
+	if (!umem->writable)
+		gup_flags |= FOLL_FORCE;
+
+	sg_list_start = umem->sg_head.sgl;
+
+	down_read(&current->mm->mmap_sem);
+	while (npages) {
+		ret = get_user_pages_longterm(cur_base,
+				     min_t(unsigned long, npages,
+					   PAGE_SIZE / sizeof (struct page *)),
+				     gup_flags, page_list, vma_list);
+		if (ret < 0) {
+			up_read(&current->mm->mmap_sem);
+			goto umem_release;
+		}
+
+		umem->npages += ret;
+		cur_base += ret * PAGE_SIZE;
+		npages   -= ret;
+
+		for_each_sg(sg_list_start, sg, ret, i) {
+			if (vma_list && !is_vm_hugetlb_page(vma_list[i]))
+				umem->hugetlb = 0;
+
+			sg_set_page(sg, page_list[i], PAGE_SIZE, 0);
+		}
+
+		/* preparing for next loop */
+		sg_list_start = sg;
+	}
+	up_read(&current->mm->mmap_sem);
+
+	umem->nmap = ib_dma_map_sg_attrs(context->device,
+				  umem->sg_head.sgl,
+				  umem->npages,
+				  DMA_BIDIRECTIONAL,
+				  dma_attrs);
+
+	if (!umem->nmap) {
+		ret = -ENOMEM;
+		goto umem_release;
+	}
+
+	ret = 0;
+	goto out;
+
+umem_release:
+	__ib_umem_release(context->device, umem, 0);
+vma:
+	down_write(&current->mm->mmap_sem);
+	current->mm->pinned_vm -= ib_umem_num_pages(umem);
+	up_write(&current->mm->mmap_sem);
+out:
+	if (vma_list)
+		free_page((unsigned long) vma_list);
+	free_page((unsigned long) page_list);
+umem_kfree:
+	if (ret)
+		kfree(umem);
+	return ret ? 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;
+	struct task_struct *task;
+	unsigned long diff;
+
+	if (umem->odp_data) {
+		ib_umem_odp_release(umem);
+		return;
+	}
+
+	__ib_umem_release(umem->context->device, umem, 1);
+
+	task = get_pid_task(umem->context->tgid, PIDTYPE_PID);
+	if (!task)
+		goto out;
+	mm = get_task_mm(task);
+	put_task_struct(task);
+	if (!mm)
+		goto out;
+
+	diff = ib_umem_num_pages(umem);
+
+	/*
+	 * 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);
+
+	mm->pinned_vm -= diff;
+	up_write(&mm->mmap_sem);
+	mmput(mm);
+out:
+	kfree(umem);
+}
+EXPORT_SYMBOL(ib_umem_release);
+
+int ib_umem_page_count(struct ib_umem *umem)
+{
+	int i;
+	int n;
+	struct scatterlist *sg;
+
+	if (umem->odp_data)
+		return ib_umem_num_pages(umem);
+
+	n = 0;
+	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i)
+		n += sg_dma_len(sg) >> umem->page_shift;
+
+	return n;
+}
+EXPORT_SYMBOL(ib_umem_page_count);
+
+/*
+ * Copy from the given ib_umem's pages to the given buffer.
+ *
+ * umem - the umem to copy from
+ * offset - offset to start copying from
+ * dst - destination buffer
+ * length - buffer length
+ *
+ * Returns 0 on success, or an error code.
+ */
+int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
+		      size_t length)
+{
+	size_t end = offset + length;
+	int ret;
+
+	if (offset > umem->length || length > umem->length - offset) {
+		pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n",
+		       offset, umem->length, end);
+		return -EINVAL;
+	}
+
+	ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->npages, dst, length,
+				 offset + ib_umem_offset(umem));
+
+	if (ret < 0)
+		return ret;
+	else if (ret != length)
+		return -EINVAL;
+	else
+		return 0;
+}
+EXPORT_SYMBOL(ib_umem_copy_from);