diff options
Diffstat (limited to 'drivers/infiniband/core/umem_odp.c')
| -rw-r--r-- | drivers/infiniband/core/umem_odp.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c new file mode 100644 index 000000000..af4af4789 --- /dev/null +++ b/drivers/infiniband/core/umem_odp.c @@ -0,0 +1,521 @@ +/* + * 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/sched/mm.h> +#include <linux/sched/task.h> +#include <linux/pid.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/vmalloc.h> +#include <linux/hugetlb.h> +#include <linux/interval_tree.h> +#include <linux/hmm.h> +#include <linux/pagemap.h> + +#include <rdma/ib_verbs.h> +#include <rdma/ib_umem.h> +#include <rdma/ib_umem_odp.h> + +#include "uverbs.h" + +static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp, + const struct mmu_interval_notifier_ops *ops) +{ + int ret; + + umem_odp->umem.is_odp = 1; + mutex_init(&umem_odp->umem_mutex); + + if (!umem_odp->is_implicit_odp) { + size_t page_size = 1UL << umem_odp->page_shift; + unsigned long start; + unsigned long end; + size_t ndmas, npfns; + + start = ALIGN_DOWN(umem_odp->umem.address, page_size); + if (check_add_overflow(umem_odp->umem.address, + (unsigned long)umem_odp->umem.length, + &end)) + return -EOVERFLOW; + end = ALIGN(end, page_size); + if (unlikely(end < page_size)) + return -EOVERFLOW; + + ndmas = (end - start) >> umem_odp->page_shift; + if (!ndmas) + return -EINVAL; + + npfns = (end - start) >> PAGE_SHIFT; + umem_odp->pfn_list = kvcalloc( + npfns, sizeof(*umem_odp->pfn_list), GFP_KERNEL); + if (!umem_odp->pfn_list) + return -ENOMEM; + + umem_odp->dma_list = kvcalloc( + ndmas, sizeof(*umem_odp->dma_list), GFP_KERNEL); + if (!umem_odp->dma_list) { + ret = -ENOMEM; + goto out_pfn_list; + } + + ret = mmu_interval_notifier_insert(&umem_odp->notifier, + umem_odp->umem.owning_mm, + start, end - start, ops); + if (ret) + goto out_dma_list; + } + + return 0; + +out_dma_list: + kvfree(umem_odp->dma_list); +out_pfn_list: + kvfree(umem_odp->pfn_list); + return ret; +} + +/** + * ib_umem_odp_alloc_implicit - Allocate a parent implicit ODP umem + * + * Implicit ODP umems do not have a VA range and do not have any page lists. + * They exist only to hold the per_mm reference to help the driver create + * children umems. + * + * @device: IB device to create UMEM + * @access: ib_reg_mr access flags + */ +struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device, + int access) +{ + struct ib_umem *umem; + struct ib_umem_odp *umem_odp; + int ret; + + if (access & IB_ACCESS_HUGETLB) + return ERR_PTR(-EINVAL); + + umem_odp = kzalloc(sizeof(*umem_odp), GFP_KERNEL); + if (!umem_odp) + return ERR_PTR(-ENOMEM); + umem = &umem_odp->umem; + umem->ibdev = device; + umem->writable = ib_access_writable(access); + umem->owning_mm = current->mm; + umem_odp->is_implicit_odp = 1; + umem_odp->page_shift = PAGE_SHIFT; + + umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID); + ret = ib_init_umem_odp(umem_odp, NULL); + if (ret) { + put_pid(umem_odp->tgid); + kfree(umem_odp); + return ERR_PTR(ret); + } + return umem_odp; +} +EXPORT_SYMBOL(ib_umem_odp_alloc_implicit); + +/** + * ib_umem_odp_alloc_child - Allocate a child ODP umem under an implicit + * parent ODP umem + * + * @root: The parent umem enclosing the child. This must be allocated using + * ib_alloc_implicit_odp_umem() + * @addr: The starting userspace VA + * @size: The length of the userspace VA + * @ops: MMU interval ops, currently only @invalidate + */ +struct ib_umem_odp * +ib_umem_odp_alloc_child(struct ib_umem_odp *root, unsigned long addr, + size_t size, + const struct mmu_interval_notifier_ops *ops) +{ + /* + * Caller must ensure that root cannot be freed during the call to + * ib_alloc_odp_umem. + */ + struct ib_umem_odp *odp_data; + struct ib_umem *umem; + int ret; + + if (WARN_ON(!root->is_implicit_odp)) + return ERR_PTR(-EINVAL); + + odp_data = kzalloc(sizeof(*odp_data), GFP_KERNEL); + if (!odp_data) + return ERR_PTR(-ENOMEM); + umem = &odp_data->umem; + umem->ibdev = root->umem.ibdev; + umem->length = size; + umem->address = addr; + umem->writable = root->umem.writable; + umem->owning_mm = root->umem.owning_mm; + odp_data->page_shift = PAGE_SHIFT; + odp_data->notifier.ops = ops; + + /* + * A mmget must be held when registering a notifier, the owming_mm only + * has a mm_grab at this point. + */ + if (!mmget_not_zero(umem->owning_mm)) { + ret = -EFAULT; + goto out_free; + } + + odp_data->tgid = get_pid(root->tgid); + ret = ib_init_umem_odp(odp_data, ops); + if (ret) + goto out_tgid; + mmput(umem->owning_mm); + return odp_data; + +out_tgid: + put_pid(odp_data->tgid); + mmput(umem->owning_mm); +out_free: + kfree(odp_data); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(ib_umem_odp_alloc_child); + +/** + * ib_umem_odp_get - Create a umem_odp for a userspace va + * + * @device: IB device struct to get UMEM + * @addr: userspace virtual address to start at + * @size: length of region to pin + * @access: IB_ACCESS_xxx flags for memory being pinned + * @ops: MMU interval ops, currently only @invalidate + * + * The driver should use when the access flags indicate ODP memory. It avoids + * pinning, instead, stores the mm for future page fault handling in + * conjunction with MMU notifiers. + */ +struct ib_umem_odp *ib_umem_odp_get(struct ib_device *device, + unsigned long addr, size_t size, int access, + const struct mmu_interval_notifier_ops *ops) +{ + struct ib_umem_odp *umem_odp; + struct mm_struct *mm; + int ret; + + if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND))) + return ERR_PTR(-EINVAL); + + umem_odp = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL); + if (!umem_odp) + return ERR_PTR(-ENOMEM); + + umem_odp->umem.ibdev = device; + umem_odp->umem.length = size; + umem_odp->umem.address = addr; + umem_odp->umem.writable = ib_access_writable(access); + umem_odp->umem.owning_mm = mm = current->mm; + umem_odp->notifier.ops = ops; + + umem_odp->page_shift = PAGE_SHIFT; +#ifdef CONFIG_HUGETLB_PAGE + if (access & IB_ACCESS_HUGETLB) + umem_odp->page_shift = HPAGE_SHIFT; +#endif + + umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID); + ret = ib_init_umem_odp(umem_odp, ops); + if (ret) + goto err_put_pid; + return umem_odp; + +err_put_pid: + put_pid(umem_odp->tgid); + kfree(umem_odp); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(ib_umem_odp_get); + +void ib_umem_odp_release(struct ib_umem_odp *umem_odp) +{ + /* + * 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. + */ + if (!umem_odp->is_implicit_odp) { + mutex_lock(&umem_odp->umem_mutex); + ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem_odp), + ib_umem_end(umem_odp)); + mutex_unlock(&umem_odp->umem_mutex); + mmu_interval_notifier_remove(&umem_odp->notifier); + kvfree(umem_odp->dma_list); + kvfree(umem_odp->pfn_list); + } + put_pid(umem_odp->tgid); + kfree(umem_odp); +} +EXPORT_SYMBOL(ib_umem_odp_release); + +/* + * Map for DMA and insert a single page into the on-demand paging page tables. + * + * @umem: the umem to insert the page to. + * @dma_index: index in the umem to add the dma 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->notifiers_seq. + * + * The function returns -EFAULT if the DMA mapping operation fails. + * + */ +static int ib_umem_odp_map_dma_single_page( + struct ib_umem_odp *umem_odp, + unsigned int dma_index, + struct page *page, + u64 access_mask) +{ + struct ib_device *dev = umem_odp->umem.ibdev; + dma_addr_t *dma_addr = &umem_odp->dma_list[dma_index]; + + if (*dma_addr) { + /* + * If the page is already dma mapped it means it went through + * a non-invalidating trasition, like read-only to writable. + * Resync the flags. + */ + *dma_addr = (*dma_addr & ODP_DMA_ADDR_MASK) | access_mask; + return 0; + } + + *dma_addr = ib_dma_map_page(dev, page, 0, 1 << umem_odp->page_shift, + DMA_BIDIRECTIONAL); + if (ib_dma_mapping_error(dev, *dma_addr)) { + *dma_addr = 0; + return -EFAULT; + } + umem_odp->npages++; + *dma_addr |= access_mask; + return 0; +} + +/** + * ib_umem_odp_map_dma_and_lock - DMA map userspace memory in an ODP MR and lock it. + * + * Maps the range passed in the argument to DMA addresses. + * The DMA addresses of the mapped pages is updated in umem_odp->dma_list. + * Upon success the ODP MR will be locked to let caller complete its device + * page table update. + * + * Returns the number of pages mapped in success, negative error code + * for failure. + * @umem_odp: 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. + * @fault: is faulting required for the given range + */ +int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt, + u64 bcnt, u64 access_mask, bool fault) + __acquires(&umem_odp->umem_mutex) +{ + struct task_struct *owning_process = NULL; + struct mm_struct *owning_mm = umem_odp->umem.owning_mm; + int pfn_index, dma_index, ret = 0, start_idx; + unsigned int page_shift, hmm_order, pfn_start_idx; + unsigned long num_pfns, current_seq; + struct hmm_range range = {}; + unsigned long timeout; + + if (access_mask == 0) + return -EINVAL; + + if (user_virt < ib_umem_start(umem_odp) || + user_virt + bcnt > ib_umem_end(umem_odp)) + return -EFAULT; + + page_shift = umem_odp->page_shift; + + /* + * owning_process is allowed to be NULL, this means somehow the mm is + * existing beyond the lifetime of the originating process.. Presumably + * mmget_not_zero will fail in this case. + */ + owning_process = get_pid_task(umem_odp->tgid, PIDTYPE_PID); + if (!owning_process || !mmget_not_zero(owning_mm)) { + ret = -EINVAL; + goto out_put_task; + } + + range.notifier = &umem_odp->notifier; + range.start = ALIGN_DOWN(user_virt, 1UL << page_shift); + range.end = ALIGN(user_virt + bcnt, 1UL << page_shift); + pfn_start_idx = (range.start - ib_umem_start(umem_odp)) >> PAGE_SHIFT; + num_pfns = (range.end - range.start) >> PAGE_SHIFT; + if (fault) { + range.default_flags = HMM_PFN_REQ_FAULT; + + if (access_mask & ODP_WRITE_ALLOWED_BIT) + range.default_flags |= HMM_PFN_REQ_WRITE; + } + + range.hmm_pfns = &(umem_odp->pfn_list[pfn_start_idx]); + timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + +retry: + current_seq = range.notifier_seq = + mmu_interval_read_begin(&umem_odp->notifier); + + mmap_read_lock(owning_mm); + ret = hmm_range_fault(&range); + mmap_read_unlock(owning_mm); + if (unlikely(ret)) { + if (ret == -EBUSY && !time_after(jiffies, timeout)) + goto retry; + goto out_put_mm; + } + + start_idx = (range.start - ib_umem_start(umem_odp)) >> page_shift; + dma_index = start_idx; + + mutex_lock(&umem_odp->umem_mutex); + if (mmu_interval_read_retry(&umem_odp->notifier, current_seq)) { + mutex_unlock(&umem_odp->umem_mutex); + goto retry; + } + + for (pfn_index = 0; pfn_index < num_pfns; + pfn_index += 1 << (page_shift - PAGE_SHIFT), dma_index++) { + + if (fault) { + /* + * Since we asked for hmm_range_fault() to populate + * pages it shouldn't return an error entry on success. + */ + WARN_ON(range.hmm_pfns[pfn_index] & HMM_PFN_ERROR); + WARN_ON(!(range.hmm_pfns[pfn_index] & HMM_PFN_VALID)); + } else { + if (!(range.hmm_pfns[pfn_index] & HMM_PFN_VALID)) { + WARN_ON(umem_odp->dma_list[dma_index]); + continue; + } + access_mask = ODP_READ_ALLOWED_BIT; + if (range.hmm_pfns[pfn_index] & HMM_PFN_WRITE) + access_mask |= ODP_WRITE_ALLOWED_BIT; + } + + hmm_order = hmm_pfn_to_map_order(range.hmm_pfns[pfn_index]); + /* If a hugepage was detected and ODP wasn't set for, the umem + * page_shift will be used, the opposite case is an error. + */ + if (hmm_order + PAGE_SHIFT < page_shift) { + ret = -EINVAL; + ibdev_dbg(umem_odp->umem.ibdev, + "%s: un-expected hmm_order %d, page_shift %d\n", + __func__, hmm_order, page_shift); + break; + } + + ret = ib_umem_odp_map_dma_single_page( + umem_odp, dma_index, hmm_pfn_to_page(range.hmm_pfns[pfn_index]), + access_mask); + if (ret < 0) { + ibdev_dbg(umem_odp->umem.ibdev, + "ib_umem_odp_map_dma_single_page failed with error %d\n", ret); + break; + } + } + /* upon sucesss lock should stay on hold for the callee */ + if (!ret) + ret = dma_index - start_idx; + else + mutex_unlock(&umem_odp->umem_mutex); + +out_put_mm: + mmput_async(owning_mm); +out_put_task: + if (owning_process) + put_task_struct(owning_process); + return ret; +} +EXPORT_SYMBOL(ib_umem_odp_map_dma_and_lock); + +void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 virt, + u64 bound) +{ + dma_addr_t dma_addr; + dma_addr_t dma; + int idx; + u64 addr; + struct ib_device *dev = umem_odp->umem.ibdev; + + lockdep_assert_held(&umem_odp->umem_mutex); + + virt = max_t(u64, virt, ib_umem_start(umem_odp)); + bound = min_t(u64, bound, ib_umem_end(umem_odp)); + for (addr = virt; addr < bound; addr += BIT(umem_odp->page_shift)) { + idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift; + dma = umem_odp->dma_list[idx]; + + /* The access flags guaranteed a valid DMA address in case was NULL */ + if (dma) { + unsigned long pfn_idx = (addr - ib_umem_start(umem_odp)) >> PAGE_SHIFT; + struct page *page = hmm_pfn_to_page(umem_odp->pfn_list[pfn_idx]); + + dma_addr = dma & ODP_DMA_ADDR_MASK; + ib_dma_unmap_page(dev, dma_addr, + BIT(umem_odp->page_shift), + DMA_BIDIRECTIONAL); + if (dma & ODP_WRITE_ALLOWED_BIT) { + struct page *head_page = compound_head(page); + /* + * set_page_dirty prefers being called with + * the page lock. However, MMU notifiers are + * called sometimes with and sometimes without + * the lock. We rely on the umem_mutex instead + * to prevent other mmu notifiers from + * continuing and allowing the page mapping to + * be removed. + */ + set_page_dirty(head_page); + } + umem_odp->dma_list[idx] = 0; + umem_odp->npages--; + } + } +} +EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); |