1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0 3 * 4 * Copyright (c) 2014 Mellanox Technologies. All rights reserved. 5 * 6 * This software is available to you under a choice of one of two 7 * licenses. You may choose to be licensed under the terms of the GNU 8 * General Public License (GPL) Version 2, available from the file 9 * COPYING in the main directory of this source tree, or the 10 * OpenIB.org BSD license below: 11 * 12 * Redistribution and use in source and binary forms, with or 13 * without modification, are permitted provided that the following 14 * conditions are met: 15 * 16 * - Redistributions of source code must retain the above 17 * copyright notice, this list of conditions and the following 18 * disclaimer. 19 * 20 * - Redistributions in binary form must reproduce the above 21 * copyright notice, this list of conditions and the following 22 * disclaimer in the documentation and/or other materials 23 * provided with the distribution. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 32 * SOFTWARE. 33 * 34 * $FreeBSD$ 35 */ 36 37 #ifndef IB_UMEM_ODP_H 38 #define IB_UMEM_ODP_H 39 40 #include <linux/rbtree.h> 41 42 #include <rdma/ib_umem.h> 43 #include <rdma/ib_verbs.h> 44 45 struct umem_odp_node { 46 u64 __subtree_last; 47 struct rb_node rb; 48 }; 49 50 struct ib_umem_odp { 51 /* 52 * An array of the pages included in the on-demand paging umem. 53 * Indices of pages that are currently not mapped into the device will 54 * contain NULL. 55 */ 56 struct page **page_list; 57 /* 58 * An array of the same size as page_list, with DMA addresses mapped 59 * for pages the pages in page_list. The lower two bits designate 60 * access permissions. See ODP_READ_ALLOWED_BIT and 61 * ODP_WRITE_ALLOWED_BIT. 62 */ 63 dma_addr_t *dma_list; 64 /* 65 * The umem_mutex protects the page_list and dma_list fields of an ODP 66 * umem, allowing only a single thread to map/unmap pages. The mutex 67 * also protects access to the mmu notifier counters. 68 */ 69 struct mutex umem_mutex; 70 void *private; /* for the HW driver to use. */ 71 72 /* When false, use the notifier counter in the ucontext struct. */ 73 bool mn_counters_active; 74 int notifiers_seq; 75 int notifiers_count; 76 77 /* A linked list of umems that don't have private mmu notifier 78 * counters yet. */ 79 struct list_head no_private_counters; 80 struct ib_umem *umem; 81 82 /* Tree tracking */ 83 struct umem_odp_node interval_tree; 84 85 struct completion notifier_completion; 86 int dying; 87 }; 88 89 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING 90 91 int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem); 92 93 void ib_umem_odp_release(struct ib_umem *umem); 94 95 /* 96 * The lower 2 bits of the DMA address signal the R/W permissions for 97 * the entry. To upgrade the permissions, provide the appropriate 98 * bitmask to the map_dma_pages function. 99 * 100 * Be aware that upgrading a mapped address might result in change of 101 * the DMA address for the page. 102 */ 103 #define ODP_READ_ALLOWED_BIT (1<<0ULL) 104 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL) 105 106 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) 107 108 int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 start_offset, u64 bcnt, 109 u64 access_mask, unsigned long current_seq); 110 111 void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 start_offset, 112 u64 bound); 113 114 void rbt_ib_umem_insert(struct umem_odp_node *node, struct rb_root *root); 115 void rbt_ib_umem_remove(struct umem_odp_node *node, struct rb_root *root); 116 typedef int (*umem_call_back)(struct ib_umem *item, u64 start, u64 end, 117 void *cookie); 118 /* 119 * Call the callback on each ib_umem in the range. Returns the logical or of 120 * the return values of the functions called. 121 */ 122 int rbt_ib_umem_for_each_in_range(struct rb_root *root, u64 start, u64 end, 123 umem_call_back cb, void *cookie); 124 125 struct umem_odp_node *rbt_ib_umem_iter_first(struct rb_root *root, 126 u64 start, u64 last); 127 struct umem_odp_node *rbt_ib_umem_iter_next(struct umem_odp_node *node, 128 u64 start, u64 last); 129 130 static inline int ib_umem_mmu_notifier_retry(struct ib_umem *item, 131 unsigned long mmu_seq) 132 { 133 /* 134 * This code is strongly based on the KVM code from 135 * mmu_notifier_retry. Should be called with 136 * the relevant locks taken (item->odp_data->umem_mutex 137 * and the ucontext umem_mutex semaphore locked for read). 138 */ 139 140 /* Do not allow page faults while the new ib_umem hasn't seen a state 141 * with zero notifiers yet, and doesn't have its own valid set of 142 * private counters. */ 143 if (!item->odp_data->mn_counters_active) 144 return 1; 145 146 if (unlikely(item->odp_data->notifiers_count)) 147 return 1; 148 if (item->odp_data->notifiers_seq != mmu_seq) 149 return 1; 150 return 0; 151 } 152 153 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 154 155 static inline int ib_umem_odp_get(struct ib_ucontext *context, 156 struct ib_umem *umem) 157 { 158 return -EINVAL; 159 } 160 161 static inline void ib_umem_odp_release(struct ib_umem *umem) {} 162 163 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 164 165 #endif /* IB_UMEM_ODP_H */ 166