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 <linux/rbtree.h> 37 38 #include <rdma/ib_umem.h> 39 #include <rdma/ib_verbs.h> 40 41 struct umem_odp_node { 42 u64 __subtree_last; 43 struct rb_node rb; 44 }; 45 46 struct ib_umem_odp { 47 /* 48 * An array of the pages included in the on-demand paging umem. 49 * Indices of pages that are currently not mapped into the device will 50 * contain NULL. 51 */ 52 struct page **page_list; 53 /* 54 * An array of the same size as page_list, with DMA addresses mapped 55 * for pages the pages in page_list. The lower two bits designate 56 * access permissions. See ODP_READ_ALLOWED_BIT and 57 * ODP_WRITE_ALLOWED_BIT. 58 */ 59 dma_addr_t *dma_list; 60 /* 61 * The umem_mutex protects the page_list and dma_list fields of an ODP 62 * umem, allowing only a single thread to map/unmap pages. The mutex 63 * also protects access to the mmu notifier counters. 64 */ 65 struct mutex umem_mutex; 66 void *private; /* for the HW driver to use. */ 67 68 /* When false, use the notifier counter in the ucontext struct. */ 69 bool mn_counters_active; 70 int notifiers_seq; 71 int notifiers_count; 72 73 /* A linked list of umems that don't have private mmu notifier 74 * counters yet. */ 75 struct list_head no_private_counters; 76 struct ib_umem *umem; 77 78 /* Tree tracking */ 79 struct umem_odp_node interval_tree; 80 81 struct completion notifier_completion; 82 int dying; 83 }; 84 85 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING 86 87 int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem); 88 89 void ib_umem_odp_release(struct ib_umem *umem); 90 91 /* 92 * The lower 2 bits of the DMA address signal the R/W permissions for 93 * the entry. To upgrade the permissions, provide the appropriate 94 * bitmask to the map_dma_pages function. 95 * 96 * Be aware that upgrading a mapped address might result in change of 97 * the DMA address for the page. 98 */ 99 #define ODP_READ_ALLOWED_BIT (1<<0ULL) 100 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL) 101 102 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) 103 104 int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 start_offset, u64 bcnt, 105 u64 access_mask, unsigned long current_seq); 106 107 void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 start_offset, 108 u64 bound); 109 110 void rbt_ib_umem_insert(struct umem_odp_node *node, struct rb_root *root); 111 void rbt_ib_umem_remove(struct umem_odp_node *node, struct rb_root *root); 112 typedef int (*umem_call_back)(struct ib_umem *item, u64 start, u64 end, 113 void *cookie); 114 /* 115 * Call the callback on each ib_umem in the range. Returns the logical or of 116 * the return values of the functions called. 117 */ 118 int rbt_ib_umem_for_each_in_range(struct rb_root *root, u64 start, u64 end, 119 umem_call_back cb, void *cookie); 120 121 struct umem_odp_node *rbt_ib_umem_iter_first(struct rb_root *root, 122 u64 start, u64 last); 123 struct umem_odp_node *rbt_ib_umem_iter_next(struct umem_odp_node *node, 124 u64 start, u64 last); 125 126 static inline int ib_umem_mmu_notifier_retry(struct ib_umem *item, 127 unsigned long mmu_seq) 128 { 129 /* 130 * This code is strongly based on the KVM code from 131 * mmu_notifier_retry. Should be called with 132 * the relevant locks taken (item->odp_data->umem_mutex 133 * and the ucontext umem_mutex semaphore locked for read). 134 */ 135 136 /* Do not allow page faults while the new ib_umem hasn't seen a state 137 * with zero notifiers yet, and doesn't have its own valid set of 138 * private counters. */ 139 if (!item->odp_data->mn_counters_active) 140 return 1; 141 142 if (unlikely(item->odp_data->notifiers_count)) 143 return 1; 144 if (item->odp_data->notifiers_seq != mmu_seq) 145 return 1; 146 return 0; 147 } 148 149 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 150 151 static inline int ib_umem_odp_get(struct ib_ucontext *context, 152 struct ib_umem *umem) 153 { 154 return -EINVAL; 155 } 156 157 static inline void ib_umem_odp_release(struct ib_umem *umem) {} 158 159 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 160 161 #endif /* IB_UMEM_ODP_H */ 162