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 int npages; 73 74 /* Tree tracking */ 75 struct umem_odp_node interval_tree; 76 77 struct completion notifier_completion; 78 int dying; 79 unsigned int page_shift; 80 struct work_struct work; 81 }; 82 83 static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem) 84 { 85 return container_of(umem, struct ib_umem_odp, umem); 86 } 87 88 /* Returns the first page of an ODP umem. */ 89 static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp) 90 { 91 return ALIGN_DOWN(umem_odp->umem.address, 1UL << umem_odp->page_shift); 92 } 93 94 /* Returns the address of the page after the last one of an ODP umem. */ 95 static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp) 96 { 97 return ALIGN(umem_odp->umem.address + umem_odp->umem.length, 98 1UL << umem_odp->page_shift); 99 } 100 101 static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp) 102 { 103 return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >> 104 umem_odp->page_shift; 105 } 106 107 /* 108 * The lower 2 bits of the DMA address signal the R/W permissions for 109 * the entry. To upgrade the permissions, provide the appropriate 110 * bitmask to the map_dma_pages function. 111 * 112 * Be aware that upgrading a mapped address might result in change of 113 * the DMA address for the page. 114 */ 115 #define ODP_READ_ALLOWED_BIT (1<<0ULL) 116 #define ODP_WRITE_ALLOWED_BIT (1<<1ULL) 117 118 #define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) 119 120 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING 121 122 struct ib_ucontext_per_mm { 123 struct ib_ucontext *context; 124 struct mm_struct *mm; 125 struct pid *tgid; 126 bool active; 127 128 struct rb_root_cached umem_tree; 129 /* Protects umem_tree */ 130 struct rw_semaphore umem_rwsem; 131 132 struct mmu_notifier mn; 133 unsigned int odp_mrs_count; 134 135 struct list_head ucontext_list; 136 struct rcu_head rcu; 137 }; 138 139 int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access); 140 struct ib_umem_odp *ib_alloc_odp_umem(struct ib_umem_odp *root_umem, 141 unsigned long addr, size_t size); 142 void ib_umem_odp_release(struct ib_umem_odp *umem_odp); 143 144 int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, 145 u64 bcnt, u64 access_mask, 146 unsigned long current_seq); 147 148 void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset, 149 u64 bound); 150 151 typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end, 152 void *cookie); 153 /* 154 * Call the callback on each ib_umem in the range. Returns the logical or of 155 * the return values of the functions called. 156 */ 157 int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root, 158 u64 start, u64 end, 159 umem_call_back cb, 160 bool blockable, void *cookie); 161 162 /* 163 * Find first region intersecting with address range. 164 * Return NULL if not found 165 */ 166 struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root, 167 u64 addr, u64 length); 168 169 static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp, 170 unsigned long mmu_seq) 171 { 172 /* 173 * This code is strongly based on the KVM code from 174 * mmu_notifier_retry. Should be called with 175 * the relevant locks taken (umem_odp->umem_mutex 176 * and the ucontext umem_mutex semaphore locked for read). 177 */ 178 179 if (unlikely(umem_odp->notifiers_count)) 180 return 1; 181 if (umem_odp->notifiers_seq != mmu_seq) 182 return 1; 183 return 0; 184 } 185 186 #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 187 188 static inline int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 189 { 190 return -EINVAL; 191 } 192 193 static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {} 194 195 #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ 196 197 #endif /* IB_UMEM_ODP_H */ 198