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 struct work_struct work; 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 int access); 89 struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context, 90 unsigned long addr, 91 size_t size); 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 typedef int (*umem_call_back)(struct ib_umem *item, u64 start, u64 end, 115 void *cookie); 116 /* 117 * Call the callback on each ib_umem in the range. Returns the logical or of 118 * the return values of the functions called. 119 */ 120 int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root, 121 u64 start, u64 end, 122 umem_call_back cb, void *cookie); 123 124 /* 125 * Find first region intersecting with address range. 126 * Return NULL if not found 127 */ 128 struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root, 129 u64 addr, u64 length); 130 131 static inline int ib_umem_mmu_notifier_retry(struct ib_umem *item, 132 unsigned long mmu_seq) 133 { 134 /* 135 * This code is strongly based on the KVM code from 136 * mmu_notifier_retry. Should be called with 137 * the relevant locks taken (item->odp_data->umem_mutex 138 * and the ucontext umem_mutex semaphore locked for read). 139 */ 140 141 /* Do not allow page faults while the new ib_umem hasn't seen a state 142 * with zero notifiers yet, and doesn't have its own valid set of 143 * private counters. */ 144 if (!item->odp_data->mn_counters_active) 145 return 1; 146 147 if (unlikely(item->odp_data->notifiers_count)) 148 return 1; 149 if (item->odp_data->notifiers_seq != mmu_seq) 150 return 1; 151 return 0; 152 } 153 154 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 155 156 static inline int ib_umem_odp_get(struct ib_ucontext *context, 157 struct ib_umem *umem, 158 int access) 159 { 160 return -EINVAL; 161 } 162 163 static inline struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context, 164 unsigned long addr, 165 size_t size) 166 { 167 return ERR_PTR(-EINVAL); 168 } 169 170 static inline void ib_umem_odp_release(struct ib_umem *umem) {} 171 172 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 173 174 #endif /* IB_UMEM_ODP_H */ 175