357 строки
9.0 KiB
C
357 строки
9.0 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/signal.h>
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#include <linux/sched/mm.h>
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#include <linux/export.h>
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#include <linux/hugetlb.h>
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#include <linux/slab.h>
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#include <rdma/ib_umem_odp.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->npages,
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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 (!PageDirty(page) && 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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}
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/**
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* ib_umem_get - Pin and DMA map userspace memory.
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*
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* If access flags indicate ODP memory, avoid pinning. Instead, stores
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* the mm for future page fault handling in conjunction with MMU notifiers.
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*
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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 lock_limit;
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unsigned long new_pinned;
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unsigned long cur_base;
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struct mm_struct *mm;
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unsigned long npages;
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int ret;
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int i;
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unsigned long dma_attrs = 0;
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struct scatterlist *sg, *sg_list_start;
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unsigned int gup_flags = FOLL_WRITE;
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if (dmasync)
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dma_attrs |= DMA_ATTR_WRITE_BARRIER;
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/*
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* If the combination of the addr and size requested for this memory
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* region causes an integer overflow, return error.
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*/
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if (((addr + size) < addr) ||
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PAGE_ALIGN(addr + size) < (addr + size))
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return ERR_PTR(-EINVAL);
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if (!can_do_mlock())
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return ERR_PTR(-EPERM);
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if (access & IB_ACCESS_ON_DEMAND) {
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umem = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL);
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if (!umem)
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return ERR_PTR(-ENOMEM);
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umem->is_odp = 1;
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} else {
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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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}
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umem->context = context;
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umem->length = size;
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umem->address = addr;
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umem->page_shift = PAGE_SHIFT;
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umem->writable = ib_access_writable(access);
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umem->owning_mm = mm = current->mm;
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mmgrab(mm);
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if (access & IB_ACCESS_ON_DEMAND) {
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ret = ib_umem_odp_get(to_ib_umem_odp(umem), access);
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if (ret)
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goto umem_kfree;
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return umem;
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}
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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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ret = -ENOMEM;
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goto umem_kfree;
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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 = ib_umem_num_pages(umem);
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if (npages == 0 || npages > UINT_MAX) {
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ret = -EINVAL;
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goto out;
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}
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lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
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down_write(&mm->mmap_sem);
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if (check_add_overflow(mm->pinned_vm, npages, &new_pinned) ||
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(new_pinned > lock_limit && !capable(CAP_IPC_LOCK))) {
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up_write(&mm->mmap_sem);
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ret = -ENOMEM;
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goto out;
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}
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mm->pinned_vm = new_pinned;
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up_write(&mm->mmap_sem);
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cur_base = addr & PAGE_MASK;
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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 vma;
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if (!umem->writable)
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gup_flags |= FOLL_FORCE;
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sg_list_start = umem->sg_head.sgl;
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while (npages) {
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down_read(&mm->mmap_sem);
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ret = get_user_pages_longterm(cur_base,
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min_t(unsigned long, npages,
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PAGE_SIZE / sizeof (struct page *)),
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gup_flags, page_list, vma_list);
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if (ret < 0) {
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up_read(&mm->mmap_sem);
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goto umem_release;
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}
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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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/* Continue to hold the mmap_sem as vma_list access
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* needs to be protected.
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*/
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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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up_read(&mm->mmap_sem);
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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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dma_attrs);
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if (!umem->nmap) {
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ret = -ENOMEM;
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goto umem_release;
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}
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ret = 0;
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goto out;
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umem_release:
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__ib_umem_release(context->device, umem, 0);
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vma:
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down_write(&mm->mmap_sem);
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mm->pinned_vm -= ib_umem_num_pages(umem);
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up_write(&mm->mmap_sem);
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out:
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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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umem_kfree:
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if (ret) {
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mmdrop(umem->owning_mm);
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kfree(umem);
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}
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return ret ? 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_release_tail(struct ib_umem *umem)
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{
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mmdrop(umem->owning_mm);
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if (umem->is_odp)
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kfree(to_ib_umem_odp(umem));
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else
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kfree(umem);
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}
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static void ib_umem_release_defer(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->owning_mm->mmap_sem);
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umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
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up_write(&umem->owning_mm->mmap_sem);
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__ib_umem_release_tail(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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if (umem->is_odp) {
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ib_umem_odp_release(to_ib_umem_odp(umem));
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__ib_umem_release_tail(umem);
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return;
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}
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__ib_umem_release(umem->context->device, umem, 1);
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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 a workqueue.
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*/
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if (context->closing) {
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if (!down_write_trylock(&umem->owning_mm->mmap_sem)) {
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INIT_WORK(&umem->work, ib_umem_release_defer);
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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(&umem->owning_mm->mmap_sem);
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}
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umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
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up_write(&umem->owning_mm->mmap_sem);
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__ib_umem_release_tail(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 i;
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int n;
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struct scatterlist *sg;
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if (umem->is_odp)
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return ib_umem_num_pages(umem);
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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) >> umem->page_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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/*
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* Copy from the given ib_umem's pages to the given buffer.
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*
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* umem - the umem to copy from
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* offset - offset to start copying from
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* dst - destination buffer
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* length - buffer length
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*
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* Returns 0 on success, or an error code.
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*/
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int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
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size_t length)
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{
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size_t end = offset + length;
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int ret;
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if (offset > umem->length || length > umem->length - offset) {
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pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n",
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offset, umem->length, end);
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return -EINVAL;
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}
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ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->npages, dst, length,
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offset + ib_umem_offset(umem));
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if (ret < 0)
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return ret;
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else if (ret != length)
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return -EINVAL;
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else
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return 0;
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}
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EXPORT_SYMBOL(ib_umem_copy_from);
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