--- /dev/null
+/*
+ * 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 <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->nmap,
+ DMA_BIDIRECTIONAL);
+
+ for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) {
+
+ page = sg_page(sg);
+ if (umem->writable && dirty)
+ set_page_dirty_lock(page);
+ put_page(page);
+ }
+
+ sg_free_table(&umem->sg_head);
+ return;
+
+}
+
+/**
+ * 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 locked;
+ unsigned long lock_limit;
+ unsigned long cur_base;
+ unsigned long npages;
+ int ret;
+ int i;
+ DEFINE_DMA_ATTRS(attrs);
+ struct scatterlist *sg, *sg_list_start;
+ int need_release = 0;
+
+ if (dmasync)
+ dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
+
+ if (!size)
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * 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_size = PAGE_SIZE;
+ umem->pid = get_task_pid(current, PIDTYPE_PID);
+ /*
+ * We ask for writable memory if any of the following
+ * access flags 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_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE |
+ IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
+
+ if (access & IB_ACCESS_ON_DEMAND) {
+ ret = ib_umem_odp_get(context, umem);
+ if (ret) {
+ kfree(umem);
+ return ERR_PTR(ret);
+ }
+ 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) {
+ 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 = ib_umem_num_pages(umem);
+
+ down_write(¤t->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;
+
+ if (npages == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL);
+ if (ret)
+ goto out;
+
+ need_release = 1;
+ sg_list_start = umem->sg_head.sgl;
+
+ 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;
+
+ 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;
+ }
+
+ umem->nmap = ib_dma_map_sg_attrs(context->device,
+ umem->sg_head.sgl,
+ umem->npages,
+ DMA_BIDIRECTIONAL,
+ &attrs);
+
+ if (umem->nmap <= 0) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+ if (ret < 0) {
+ if (need_release)
+ __ib_umem_release(context->device, umem, 0);
+ put_pid(umem->pid);
+ kfree(umem);
+ } else
+ current->mm->pinned_vm = locked;
+
+ up_write(¤t->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;
+ 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->pid, PIDTYPE_PID);
+ put_pid(umem->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 shift;
+ int i;
+ int n;
+ struct scatterlist *sg;
+
+ if (umem->odp_data)
+ return ib_umem_num_pages(umem);
+
+ shift = ilog2(umem->page_size);
+
+ n = 0;
+ for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i)
+ n += sg_dma_len(sg) >> 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->nmap, 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);
Code Review / kvmfornfv.git / blobdiff