| /* |
| * 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 "uverbs.h" |
| |
| #define IB_UMEM_MAX_PAGE_CHUNK \ |
| ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \ |
| ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \ |
| (void *) &((struct ib_umem_chunk *) 0)->page_list[0])) |
| |
| static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) |
| { |
| struct ib_umem_chunk *chunk, *tmp; |
| int i; |
| |
| list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) { |
| ib_dma_unmap_sg(dev, chunk->page_list, |
| chunk->nents, DMA_BIDIRECTIONAL); |
| for (i = 0; i < chunk->nents; ++i) { |
| struct page *page = sg_page(&chunk->page_list[i]); |
| |
| if (umem->writable && dirty) |
| set_page_dirty_lock(page); |
| put_page(page); |
| } |
| |
| kfree(chunk); |
| } |
| } |
| |
| /** |
| * ib_umem_get - Pin and DMA map userspace memory. |
| * @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; |
| struct ib_umem_chunk *chunk; |
| unsigned long locked; |
| unsigned long lock_limit; |
| unsigned long cur_base; |
| unsigned long npages; |
| int ret; |
| int off; |
| int i; |
| DEFINE_DMA_ATTRS(attrs); |
| |
| if (dmasync) |
| dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs); |
| |
| if (!can_do_mlock()) |
| return ERR_PTR(-EPERM); |
| |
| umem = kmalloc(sizeof *umem, GFP_KERNEL); |
| if (!umem) |
| return ERR_PTR(-ENOMEM); |
| |
| umem->context = context; |
| umem->length = size; |
| umem->offset = addr & ~PAGE_MASK; |
| umem->page_size = PAGE_SIZE; |
| /* |
| * We ask for writable memory if any access flags other than |
| * "remote read" 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_REMOTE_READ); |
| |
| /* We assume the memory is from hugetlb until proved otherwise */ |
| umem->hugetlb = 1; |
| |
| INIT_LIST_HEAD(&umem->chunk_list); |
| |
| 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 = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT; |
| |
| down_write(¤t->mm->mmap_sem); |
| |
| locked = npages + current->mm->locked_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; |
| |
| ret = 0; |
| 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; |
| |
| cur_base += ret * PAGE_SIZE; |
| npages -= ret; |
| |
| off = 0; |
| |
| while (ret) { |
| chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) * |
| min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK), |
| GFP_KERNEL); |
| if (!chunk) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK); |
| sg_init_table(chunk->page_list, chunk->nents); |
| for (i = 0; i < chunk->nents; ++i) { |
| if (vma_list && |
| !is_vm_hugetlb_page(vma_list[i + off])) |
| umem->hugetlb = 0; |
| sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0); |
| } |
| |
| chunk->nmap = ib_dma_map_sg_attrs(context->device, |
| &chunk->page_list[0], |
| chunk->nents, |
| DMA_BIDIRECTIONAL, |
| &attrs); |
| if (chunk->nmap <= 0) { |
| for (i = 0; i < chunk->nents; ++i) |
| put_page(sg_page(&chunk->page_list[i])); |
| kfree(chunk); |
| |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret -= chunk->nents; |
| off += chunk->nents; |
| list_add_tail(&chunk->list, &umem->chunk_list); |
| } |
| |
| ret = 0; |
| } |
| |
| out: |
| if (ret < 0) { |
| __ib_umem_release(context->device, umem, 0); |
| kfree(umem); |
| } else |
| current->mm->locked_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->locked_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; |
| unsigned long diff; |
| |
| __ib_umem_release(umem->context->device, umem, 1); |
| |
| mm = get_task_mm(current); |
| if (!mm) { |
| kfree(umem); |
| return; |
| } |
| |
| diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT; |
| |
| /* |
| * 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); |
| |
| current->mm->locked_vm -= diff; |
| up_write(&mm->mmap_sem); |
| mmput(mm); |
| kfree(umem); |
| } |
| EXPORT_SYMBOL(ib_umem_release); |
| |
| int ib_umem_page_count(struct ib_umem *umem) |
| { |
| struct ib_umem_chunk *chunk; |
| int shift; |
| int i; |
| int n; |
| |
| shift = ilog2(umem->page_size); |
| |
| n = 0; |
| list_for_each_entry(chunk, &umem->chunk_list, list) |
| for (i = 0; i < chunk->nmap; ++i) |
| n += sg_dma_len(&chunk->page_list[i]) >> shift; |
| |
| return n; |
| } |
| EXPORT_SYMBOL(ib_umem_page_count); |