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