| /* |
| * 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); |
| 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; |
| unsigned long dma_attrs = 0; |
| struct scatterlist *sg, *sg_list_start; |
| int need_release = 0; |
| 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->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) { |
| put_pid(umem->pid); |
| ret = ib_umem_odp_get(context, umem, access); |
| 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) { |
| put_pid(umem->pid); |
| 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 || npages > UINT_MAX) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); |
| if (ret) |
| goto out; |
| |
| if (!umem->writable) |
| gup_flags |= FOLL_FORCE; |
| |
| need_release = 1; |
| sg_list_start = umem->sg_head.sgl; |
| |
| 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) |
| 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, |
| dma_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 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); |