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 struct ib_umem umem; 47 struct ib_ucontext_per_mm *per_mm; 48 49 /* 50 * An array of the pages included in the on-demand paging umem. 51 * Indices of pages that are currently not mapped into the device will 52 * contain NULL. 53 */ 54 struct page **page_list; 55 /* 56 * An array of the same size as page_list, with DMA addresses mapped 57 * for pages the pages in page_list. The lower two bits designate 58 * access permissions. See ODP_READ_ALLOWED_BIT and 59 * ODP_WRITE_ALLOWED_BIT. 60 */ 61 dma_addr_t *dma_list; 62 /* 63 * The umem_mutex protects the page_list and dma_list fields of an ODP 64 * umem, allowing only a single thread to map/unmap pages. The mutex 65 * also protects access to the mmu notifier counters. 66 */ 67 struct mutex umem_mutex; 68 void *private; /* for the HW driver to use. */ 69 70 int notifiers_seq; 71 int notifiers_count; 72 73 /* Tree tracking */ 74 struct umem_odp_node interval_tree; 75 76 struct completion notifier_completion; 77 int dying; 78 struct work_struct work; 79 }; 80 81 static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem) 82 { 83 return container_of(umem, struct ib_umem_odp, umem); 84 } 85 86 /* 87 * The lower 2 bits of the DMA address signal the R/W permissions for 88 * the entry. To upgrade the permissions, provide the appropriate 89 * bitmask to the map_dma_pages function. 90 * 91 * Be aware that upgrading a mapped address might result in change of 92 * the DMA address for the page. 93 */ 94 #define ODP_READ_ALLOWED_BIT (1<<0ULL) 95 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL) 96 97 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) 98 99 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING 100 101 struct ib_ucontext_per_mm { 102 struct ib_ucontext *context; 103 struct mm_struct *mm; 104 struct pid *tgid; 105 bool active; 106 107 struct rb_root_cached umem_tree; 108 /* Protects umem_tree */ 109 struct rw_semaphore umem_rwsem; 110 111 struct mmu_notifier mn; 112 unsigned int odp_mrs_count; 113 114 struct list_head ucontext_list; 115 struct rcu_head rcu; 116 }; 117 118 int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access); 119 struct ib_umem_odp *ib_alloc_odp_umem(struct ib_umem_odp *root_umem, 120 unsigned long addr, size_t size); 121 void ib_umem_odp_release(struct ib_umem_odp *umem_odp); 122 123 int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, 124 u64 bcnt, u64 access_mask, 125 unsigned long current_seq); 126 127 void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, 128 u64 bound); 129 130 typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end, 131 void *cookie); 132 /* 133 * Call the callback on each ib_umem in the range. Returns the logical or of 134 * the return values of the functions called. 135 */ 136 int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root, 137 u64 start, u64 end, 138 umem_call_back cb, 139 bool blockable, void *cookie); 140 141 /* 142 * Find first region intersecting with address range. 143 * Return NULL if not found 144 */ 145 struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root, 146 u64 addr, u64 length); 147 148 static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp, 149 unsigned long mmu_seq) 150 { 151 /* 152 * This code is strongly based on the KVM code from 153 * mmu_notifier_retry. Should be called with 154 * the relevant locks taken (umem_odp->umem_mutex 155 * and the ucontext umem_mutex semaphore locked for read). 156 */ 157 158 if (unlikely(umem_odp->notifiers_count)) 159 return 1; 160 if (umem_odp->notifiers_seq != mmu_seq) 161 return 1; 162 return 0; 163 } 164 165 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 166 167 static inline int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 168 { 169 return -EINVAL; 170 } 171 172 static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {} 173 174 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 175 176 #endif /* IB_UMEM_ODP_H */ 177