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