mirror of https://gitee.com/openkylin/linux.git
560 lines
16 KiB
C
560 lines
16 KiB
C
/*
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* Copyright (c) 2014 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/types.h>
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#include <linux/sched.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/task.h>
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#include <linux/pid.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/vmalloc.h>
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#include <linux/hugetlb.h>
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#include <linux/interval_tree.h>
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#include <linux/pagemap.h>
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#include <rdma/ib_verbs.h>
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#include <rdma/ib_umem.h>
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#include <rdma/ib_umem_odp.h>
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#include "uverbs.h"
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static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp,
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const struct mmu_interval_notifier_ops *ops)
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{
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int ret;
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umem_odp->umem.is_odp = 1;
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mutex_init(&umem_odp->umem_mutex);
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if (!umem_odp->is_implicit_odp) {
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size_t page_size = 1UL << umem_odp->page_shift;
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unsigned long start;
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unsigned long end;
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size_t pages;
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start = ALIGN_DOWN(umem_odp->umem.address, page_size);
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if (check_add_overflow(umem_odp->umem.address,
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(unsigned long)umem_odp->umem.length,
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&end))
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return -EOVERFLOW;
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end = ALIGN(end, page_size);
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if (unlikely(end < page_size))
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return -EOVERFLOW;
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pages = (end - start) >> umem_odp->page_shift;
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if (!pages)
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return -EINVAL;
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umem_odp->page_list = kvcalloc(
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pages, sizeof(*umem_odp->page_list), GFP_KERNEL);
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if (!umem_odp->page_list)
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return -ENOMEM;
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umem_odp->dma_list = kvcalloc(
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pages, sizeof(*umem_odp->dma_list), GFP_KERNEL);
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if (!umem_odp->dma_list) {
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ret = -ENOMEM;
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goto out_page_list;
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}
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ret = mmu_interval_notifier_insert(&umem_odp->notifier,
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umem_odp->umem.owning_mm,
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start, end - start, ops);
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if (ret)
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goto out_dma_list;
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}
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return 0;
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out_dma_list:
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kvfree(umem_odp->dma_list);
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out_page_list:
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kvfree(umem_odp->page_list);
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return ret;
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}
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/**
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* ib_umem_odp_alloc_implicit - Allocate a parent implicit ODP umem
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*
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* Implicit ODP umems do not have a VA range and do not have any page lists.
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* They exist only to hold the per_mm reference to help the driver create
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* children umems.
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*
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* @udata: udata from the syscall being used to create the umem
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* @access: ib_reg_mr access flags
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*/
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struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
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int access)
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{
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struct ib_ucontext *context =
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container_of(udata, struct uverbs_attr_bundle, driver_udata)
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->context;
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struct ib_umem *umem;
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struct ib_umem_odp *umem_odp;
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int ret;
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if (access & IB_ACCESS_HUGETLB)
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return ERR_PTR(-EINVAL);
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if (!context)
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return ERR_PTR(-EIO);
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umem_odp = kzalloc(sizeof(*umem_odp), GFP_KERNEL);
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if (!umem_odp)
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return ERR_PTR(-ENOMEM);
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umem = &umem_odp->umem;
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umem->ibdev = context->device;
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umem->writable = ib_access_writable(access);
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umem->owning_mm = current->mm;
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umem_odp->is_implicit_odp = 1;
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umem_odp->page_shift = PAGE_SHIFT;
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umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
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ret = ib_init_umem_odp(umem_odp, NULL);
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if (ret) {
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put_pid(umem_odp->tgid);
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kfree(umem_odp);
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return ERR_PTR(ret);
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}
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return umem_odp;
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}
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EXPORT_SYMBOL(ib_umem_odp_alloc_implicit);
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/**
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* ib_umem_odp_alloc_child - Allocate a child ODP umem under an implicit
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* parent ODP umem
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*
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* @root: The parent umem enclosing the child. This must be allocated using
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* ib_alloc_implicit_odp_umem()
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* @addr: The starting userspace VA
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* @size: The length of the userspace VA
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*/
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struct ib_umem_odp *
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ib_umem_odp_alloc_child(struct ib_umem_odp *root, unsigned long addr,
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size_t size,
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const struct mmu_interval_notifier_ops *ops)
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{
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/*
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* Caller must ensure that root cannot be freed during the call to
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* ib_alloc_odp_umem.
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*/
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struct ib_umem_odp *odp_data;
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struct ib_umem *umem;
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int ret;
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if (WARN_ON(!root->is_implicit_odp))
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return ERR_PTR(-EINVAL);
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odp_data = kzalloc(sizeof(*odp_data), GFP_KERNEL);
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if (!odp_data)
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return ERR_PTR(-ENOMEM);
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umem = &odp_data->umem;
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umem->ibdev = root->umem.ibdev;
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umem->length = size;
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umem->address = addr;
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umem->writable = root->umem.writable;
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umem->owning_mm = root->umem.owning_mm;
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odp_data->page_shift = PAGE_SHIFT;
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odp_data->notifier.ops = ops;
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odp_data->tgid = get_pid(root->tgid);
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ret = ib_init_umem_odp(odp_data, ops);
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if (ret) {
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put_pid(odp_data->tgid);
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kfree(odp_data);
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return ERR_PTR(ret);
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}
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return odp_data;
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}
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EXPORT_SYMBOL(ib_umem_odp_alloc_child);
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/**
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* ib_umem_odp_get - Create a umem_odp for a userspace va
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*
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* @udata: 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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*
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* The driver should use when the access flags indicate ODP memory. It avoids
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* pinning, instead, stores the mm for future page fault handling in
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* conjunction with MMU notifiers.
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*/
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struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
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size_t size, int access,
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const struct mmu_interval_notifier_ops *ops)
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{
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struct ib_umem_odp *umem_odp;
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struct ib_ucontext *context;
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struct mm_struct *mm;
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int ret;
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if (!udata)
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return ERR_PTR(-EIO);
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context = container_of(udata, struct uverbs_attr_bundle, driver_udata)
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->context;
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if (!context)
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return ERR_PTR(-EIO);
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if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND)))
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return ERR_PTR(-EINVAL);
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umem_odp = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL);
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if (!umem_odp)
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return ERR_PTR(-ENOMEM);
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umem_odp->umem.ibdev = context->device;
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umem_odp->umem.length = size;
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umem_odp->umem.address = addr;
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umem_odp->umem.writable = ib_access_writable(access);
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umem_odp->umem.owning_mm = mm = current->mm;
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umem_odp->notifier.ops = ops;
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if (access & IB_ACCESS_HUGETLB)
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umem_odp->page_shift = HPAGE_SHIFT;
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else
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umem_odp->page_shift = PAGE_SHIFT;
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umem_odp->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
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ret = ib_init_umem_odp(umem_odp, ops);
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if (ret)
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goto err_put_pid;
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return umem_odp;
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err_put_pid:
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put_pid(umem_odp->tgid);
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kfree(umem_odp);
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return ERR_PTR(ret);
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}
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EXPORT_SYMBOL(ib_umem_odp_get);
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void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
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{
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/*
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* Ensure that no more pages are mapped in the umem.
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*
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* It is the driver's responsibility to ensure, before calling us,
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* that the hardware will not attempt to access the MR any more.
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*/
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if (!umem_odp->is_implicit_odp) {
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mutex_lock(&umem_odp->umem_mutex);
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ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem_odp),
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ib_umem_end(umem_odp));
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mutex_unlock(&umem_odp->umem_mutex);
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mmu_interval_notifier_remove(&umem_odp->notifier);
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kvfree(umem_odp->dma_list);
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kvfree(umem_odp->page_list);
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put_pid(umem_odp->tgid);
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}
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kfree(umem_odp);
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}
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EXPORT_SYMBOL(ib_umem_odp_release);
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/*
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* Map for DMA and insert a single page into the on-demand paging page tables.
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*
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* @umem: the umem to insert the page to.
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* @page_index: index in the umem to add the page to.
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* @page: the page struct to map and add.
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* @access_mask: access permissions needed for this page.
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* @current_seq: sequence number for synchronization with invalidations.
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* the sequence number is taken from
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* umem_odp->notifiers_seq.
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*
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* The function returns -EFAULT if the DMA mapping operation fails. It returns
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* -EAGAIN if a concurrent invalidation prevents us from updating the page.
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*
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* The page is released via put_user_page even if the operation failed. For
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* on-demand pinning, the page is released whenever it isn't stored in the
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* umem.
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*/
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static int ib_umem_odp_map_dma_single_page(
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struct ib_umem_odp *umem_odp,
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unsigned int page_index,
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struct page *page,
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u64 access_mask,
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unsigned long current_seq)
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{
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struct ib_device *dev = umem_odp->umem.ibdev;
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dma_addr_t dma_addr;
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int ret = 0;
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if (mmu_interval_check_retry(&umem_odp->notifier, current_seq)) {
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ret = -EAGAIN;
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goto out;
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}
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if (!(umem_odp->dma_list[page_index])) {
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dma_addr =
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ib_dma_map_page(dev, page, 0, BIT(umem_odp->page_shift),
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DMA_BIDIRECTIONAL);
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if (ib_dma_mapping_error(dev, dma_addr)) {
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ret = -EFAULT;
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goto out;
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}
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umem_odp->dma_list[page_index] = dma_addr | access_mask;
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umem_odp->page_list[page_index] = page;
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umem_odp->npages++;
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} else if (umem_odp->page_list[page_index] == page) {
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umem_odp->dma_list[page_index] |= access_mask;
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} else {
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/*
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* This is a race here where we could have done:
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*
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* CPU0 CPU1
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* get_user_pages()
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* invalidate()
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* page_fault()
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* mutex_lock(umem_mutex)
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* page from GUP != page in ODP
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*
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* It should be prevented by the retry test above as reading
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* the seq number should be reliable under the
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* umem_mutex. Thus something is really not working right if
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* things get here.
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*/
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WARN(true,
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"Got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
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umem_odp->page_list[page_index], page);
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ret = -EAGAIN;
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}
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out:
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put_user_page(page);
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return ret;
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}
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/**
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* ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR.
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*
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* Pins the range of pages passed in the argument, and maps them to
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* DMA addresses. The DMA addresses of the mapped pages is updated in
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* umem_odp->dma_list.
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*
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* Returns the number of pages mapped in success, negative error code
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* for failure.
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* An -EAGAIN error code is returned when a concurrent mmu notifier prevents
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* the function from completing its task.
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* An -ENOENT error code indicates that userspace process is being terminated
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* and mm was already destroyed.
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* @umem_odp: the umem to map and pin
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* @user_virt: the address from which we need to map.
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* @bcnt: the minimal number of bytes to pin and map. The mapping might be
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* bigger due to alignment, and may also be smaller in case of an error
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* pinning or mapping a page. The actual pages mapped is returned in
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* the return value.
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* @access_mask: bit mask of the requested access permissions for the given
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* range.
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* @current_seq: the MMU notifiers sequance value for synchronization with
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* invalidations. the sequance number is read from
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* umem_odp->notifiers_seq before calling this function
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*/
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int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt,
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u64 bcnt, u64 access_mask,
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unsigned long current_seq)
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{
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struct task_struct *owning_process = NULL;
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struct mm_struct *owning_mm = umem_odp->umem.owning_mm;
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struct page **local_page_list = NULL;
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u64 page_mask, off;
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int j, k, ret = 0, start_idx, npages = 0;
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unsigned int flags = 0, page_shift;
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phys_addr_t p = 0;
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if (access_mask == 0)
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return -EINVAL;
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if (user_virt < ib_umem_start(umem_odp) ||
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user_virt + bcnt > ib_umem_end(umem_odp))
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return -EFAULT;
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local_page_list = (struct page **)__get_free_page(GFP_KERNEL);
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if (!local_page_list)
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return -ENOMEM;
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page_shift = umem_odp->page_shift;
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page_mask = ~(BIT(page_shift) - 1);
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off = user_virt & (~page_mask);
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user_virt = user_virt & page_mask;
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bcnt += off; /* Charge for the first page offset as well. */
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/*
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* owning_process is allowed to be NULL, this means somehow the mm is
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* existing beyond the lifetime of the originating process.. Presumably
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* mmget_not_zero will fail in this case.
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*/
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owning_process = get_pid_task(umem_odp->tgid, PIDTYPE_PID);
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if (!owning_process || !mmget_not_zero(owning_mm)) {
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ret = -EINVAL;
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goto out_put_task;
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}
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if (access_mask & ODP_WRITE_ALLOWED_BIT)
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flags |= FOLL_WRITE;
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start_idx = (user_virt - ib_umem_start(umem_odp)) >> page_shift;
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k = start_idx;
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while (bcnt > 0) {
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const size_t gup_num_pages = min_t(size_t,
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ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE,
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PAGE_SIZE / sizeof(struct page *));
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down_read(&owning_mm->mmap_sem);
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/*
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* Note: this might result in redundent page getting. We can
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* avoid this by checking dma_list to be 0 before calling
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* get_user_pages. However, this make the code much more
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* complex (and doesn't gain us much performance in most use
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* cases).
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*/
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npages = get_user_pages_remote(owning_process, owning_mm,
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user_virt, gup_num_pages,
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flags, local_page_list, NULL, NULL);
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up_read(&owning_mm->mmap_sem);
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if (npages < 0) {
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if (npages != -EAGAIN)
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pr_warn("fail to get %zu user pages with error %d\n", gup_num_pages, npages);
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else
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pr_debug("fail to get %zu user pages with error %d\n", gup_num_pages, npages);
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break;
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}
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bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt);
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mutex_lock(&umem_odp->umem_mutex);
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for (j = 0; j < npages; j++, user_virt += PAGE_SIZE) {
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if (user_virt & ~page_mask) {
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p += PAGE_SIZE;
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if (page_to_phys(local_page_list[j]) != p) {
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ret = -EFAULT;
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break;
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}
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put_user_page(local_page_list[j]);
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continue;
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}
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ret = ib_umem_odp_map_dma_single_page(
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umem_odp, k, local_page_list[j],
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access_mask, current_seq);
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if (ret < 0) {
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if (ret != -EAGAIN)
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pr_warn("ib_umem_odp_map_dma_single_page failed with error %d\n", ret);
|
|
else
|
|
pr_debug("ib_umem_odp_map_dma_single_page failed with error %d\n", ret);
|
|
break;
|
|
}
|
|
|
|
p = page_to_phys(local_page_list[j]);
|
|
k++;
|
|
}
|
|
mutex_unlock(&umem_odp->umem_mutex);
|
|
|
|
if (ret < 0) {
|
|
/*
|
|
* Release pages, remembering that the first page
|
|
* to hit an error was already released by
|
|
* ib_umem_odp_map_dma_single_page().
|
|
*/
|
|
if (npages - (j + 1) > 0)
|
|
put_user_pages(&local_page_list[j+1],
|
|
npages - (j + 1));
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ret >= 0) {
|
|
if (npages < 0 && k == start_idx)
|
|
ret = npages;
|
|
else
|
|
ret = k - start_idx;
|
|
}
|
|
|
|
mmput(owning_mm);
|
|
out_put_task:
|
|
if (owning_process)
|
|
put_task_struct(owning_process);
|
|
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_odp *umem_odp, u64 virt,
|
|
u64 bound)
|
|
{
|
|
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));
|
|
/* Note that during the run of this function, the
|
|
* notifiers_count of the MR is > 0, preventing any racing
|
|
* faults from completion. We might be racing with other
|
|
* invalidations, so we must make sure we free each page only
|
|
* once. */
|
|
for (addr = virt; addr < bound; addr += BIT(umem_odp->page_shift)) {
|
|
idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift;
|
|
if (umem_odp->page_list[idx]) {
|
|
struct page *page = umem_odp->page_list[idx];
|
|
dma_addr_t dma = umem_odp->dma_list[idx];
|
|
dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK;
|
|
|
|
WARN_ON(!dma_addr);
|
|
|
|
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->page_list[idx] = NULL;
|
|
umem_odp->dma_list[idx] = 0;
|
|
umem_odp->npages--;
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
|