| /* |
| * Copyright (c) 2014 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/types.h> |
| #include <linux/sched.h> |
| #include <linux/pid.h> |
| #include <linux/slab.h> |
| #include <linux/export.h> |
| #include <linux/vmalloc.h> |
| |
| #include <rdma/ib_verbs.h> |
| #include <rdma/ib_umem.h> |
| #include <rdma/ib_umem_odp.h> |
| |
| int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem) |
| { |
| int ret_val; |
| struct pid *our_pid; |
| |
| /* Prevent creating ODP MRs in child processes */ |
| rcu_read_lock(); |
| our_pid = get_task_pid(current->group_leader, PIDTYPE_PID); |
| rcu_read_unlock(); |
| put_pid(our_pid); |
| if (context->tgid != our_pid) |
| return -EINVAL; |
| |
| umem->hugetlb = 0; |
| umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL); |
| if (!umem->odp_data) |
| return -ENOMEM; |
| |
| mutex_init(&umem->odp_data->umem_mutex); |
| |
| umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) * |
| sizeof(*umem->odp_data->page_list)); |
| if (!umem->odp_data->page_list) { |
| ret_val = -ENOMEM; |
| goto out_odp_data; |
| } |
| |
| umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) * |
| sizeof(*umem->odp_data->dma_list)); |
| if (!umem->odp_data->dma_list) { |
| ret_val = -ENOMEM; |
| goto out_page_list; |
| } |
| |
| return 0; |
| |
| out_page_list: |
| vfree(umem->odp_data->page_list); |
| out_odp_data: |
| kfree(umem->odp_data); |
| return ret_val; |
| } |
| |
| void ib_umem_odp_release(struct ib_umem *umem) |
| { |
| /* |
| * Ensure that no more pages are mapped in the umem. |
| * |
| * It is the driver's responsibility to ensure, before calling us, |
| * that the hardware will not attempt to access the MR any more. |
| */ |
| ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem), |
| ib_umem_end(umem)); |
| |
| vfree(umem->odp_data->dma_list); |
| vfree(umem->odp_data->page_list); |
| kfree(umem->odp_data); |
| kfree(umem); |
| } |
| |
| /* |
| * Map for DMA and insert a single page into the on-demand paging page tables. |
| * |
| * @umem: the umem to insert the page to. |
| * @page_index: index in the umem to add the page to. |
| * @page: the page struct to map and add. |
| * @access_mask: access permissions needed for this page. |
| * @current_seq: sequence number for synchronization with invalidations. |
| * the sequence number is taken from |
| * umem->odp_data->notifiers_seq. |
| * |
| * The function returns -EFAULT if the DMA mapping operation fails. |
| * |
| * The page is released via put_page even if the operation failed. For |
| * on-demand pinning, the page is released whenever it isn't stored in the |
| * umem. |
| */ |
| static int ib_umem_odp_map_dma_single_page( |
| struct ib_umem *umem, |
| int page_index, |
| struct page *page, |
| u64 access_mask, |
| unsigned long current_seq) |
| { |
| struct ib_device *dev = umem->context->device; |
| dma_addr_t dma_addr; |
| int stored_page = 0; |
| int ret = 0; |
| |
| mutex_lock(&umem->odp_data->umem_mutex); |
| if (!(umem->odp_data->dma_list[page_index])) { |
| dma_addr = ib_dma_map_page(dev, |
| page, |
| 0, PAGE_SIZE, |
| DMA_BIDIRECTIONAL); |
| if (ib_dma_mapping_error(dev, dma_addr)) { |
| ret = -EFAULT; |
| goto out; |
| } |
| umem->odp_data->dma_list[page_index] = dma_addr | access_mask; |
| umem->odp_data->page_list[page_index] = page; |
| stored_page = 1; |
| } else if (umem->odp_data->page_list[page_index] == page) { |
| umem->odp_data->dma_list[page_index] |= access_mask; |
| } else { |
| pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n", |
| umem->odp_data->page_list[page_index], page); |
| } |
| |
| out: |
| mutex_unlock(&umem->odp_data->umem_mutex); |
| |
| if (!stored_page) |
| put_page(page); |
| |
| return ret; |
| } |
| |
| /** |
| * ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR. |
| * |
| * Pins the range of pages passed in the argument, and maps them to |
| * DMA addresses. The DMA addresses of the mapped pages is updated in |
| * umem->odp_data->dma_list. |
| * |
| * Returns the number of pages mapped in success, negative error code |
| * for failure. |
| * |
| * @umem: the umem to map and pin |
| * @user_virt: the address from which we need to map. |
| * @bcnt: the minimal number of bytes to pin and map. The mapping might be |
| * bigger due to alignment, and may also be smaller in case of an error |
| * pinning or mapping a page. The actual pages mapped is returned in |
| * the return value. |
| * @access_mask: bit mask of the requested access permissions for the given |
| * range. |
| * @current_seq: the MMU notifiers sequance value for synchronization with |
| * invalidations. the sequance number is read from |
| * umem->odp_data->notifiers_seq before calling this function |
| */ |
| int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt, |
| u64 access_mask, unsigned long current_seq) |
| { |
| struct task_struct *owning_process = NULL; |
| struct mm_struct *owning_mm = NULL; |
| struct page **local_page_list = NULL; |
| u64 off; |
| int j, k, ret = 0, start_idx, npages = 0; |
| |
| if (access_mask == 0) |
| return -EINVAL; |
| |
| if (user_virt < ib_umem_start(umem) || |
| user_virt + bcnt > ib_umem_end(umem)) |
| return -EFAULT; |
| |
| local_page_list = (struct page **)__get_free_page(GFP_KERNEL); |
| if (!local_page_list) |
| return -ENOMEM; |
| |
| off = user_virt & (~PAGE_MASK); |
| user_virt = user_virt & PAGE_MASK; |
| bcnt += off; /* Charge for the first page offset as well. */ |
| |
| owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID); |
| if (owning_process == NULL) { |
| ret = -EINVAL; |
| goto out_no_task; |
| } |
| |
| owning_mm = get_task_mm(owning_process); |
| if (owning_mm == NULL) { |
| ret = -EINVAL; |
| goto out_put_task; |
| } |
| |
| start_idx = (user_virt - ib_umem_start(umem)) >> PAGE_SHIFT; |
| k = start_idx; |
| |
| while (bcnt > 0) { |
| const size_t gup_num_pages = |
| min_t(size_t, ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE, |
| PAGE_SIZE / sizeof(struct page *)); |
| |
| down_read(&owning_mm->mmap_sem); |
| /* |
| * Note: this might result in redundent page getting. We can |
| * avoid this by checking dma_list to be 0 before calling |
| * get_user_pages. However, this make the code much more |
| * complex (and doesn't gain us much performance in most use |
| * cases). |
| */ |
| npages = get_user_pages(owning_process, owning_mm, user_virt, |
| gup_num_pages, |
| access_mask & ODP_WRITE_ALLOWED_BIT, 0, |
| local_page_list, NULL); |
| up_read(&owning_mm->mmap_sem); |
| |
| if (npages < 0) |
| break; |
| |
| bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt); |
| user_virt += npages << PAGE_SHIFT; |
| for (j = 0; j < npages; ++j) { |
| ret = ib_umem_odp_map_dma_single_page( |
| umem, k, local_page_list[j], access_mask, |
| current_seq); |
| if (ret < 0) |
| break; |
| k++; |
| } |
| |
| if (ret < 0) { |
| /* Release left over pages when handling errors. */ |
| for (++j; j < npages; ++j) |
| put_page(local_page_list[j]); |
| break; |
| } |
| } |
| |
| if (ret >= 0) { |
| if (npages < 0 && k == start_idx) |
| ret = npages; |
| else |
| ret = k - start_idx; |
| } |
| |
| mmput(owning_mm); |
| out_put_task: |
| put_task_struct(owning_process); |
| out_no_task: |
| free_page((unsigned long)local_page_list); |
| return ret; |
| } |
| EXPORT_SYMBOL(ib_umem_odp_map_dma_pages); |
| |
| void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt, |
| u64 bound) |
| { |
| int idx; |
| u64 addr; |
| struct ib_device *dev = umem->context->device; |
| |
| virt = max_t(u64, virt, ib_umem_start(umem)); |
| bound = min_t(u64, bound, ib_umem_end(umem)); |
| for (addr = virt; addr < bound; addr += (u64)umem->page_size) { |
| idx = (addr - ib_umem_start(umem)) / PAGE_SIZE; |
| mutex_lock(&umem->odp_data->umem_mutex); |
| if (umem->odp_data->page_list[idx]) { |
| struct page *page = umem->odp_data->page_list[idx]; |
| struct page *head_page = compound_head(page); |
| dma_addr_t dma = umem->odp_data->dma_list[idx]; |
| dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK; |
| |
| WARN_ON(!dma_addr); |
| |
| ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE, |
| DMA_BIDIRECTIONAL); |
| if (dma & ODP_WRITE_ALLOWED_BIT) |
| set_page_dirty_lock(head_page); |
| put_page(page); |
| } |
| mutex_unlock(&umem->odp_data->umem_mutex); |
| } |
| } |
| EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); |