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1/*2 * Copyright (c) 2005 Topspin Communications. All rights reserved.3 * Copyright (c) 2005 Cisco Systems. All rights reserved.4 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.5 * Copyright (c) 2020 Intel Corporation. All rights reserved.6 *7 * This software is available to you under a choice of one of two8 * licenses. You may choose to be licensed under the terms of the GNU9 * General Public License (GPL) Version 2, available from the file10 * COPYING in the main directory of this source tree, or the11 * OpenIB.org BSD license below:12 *13 * Redistribution and use in source and binary forms, with or14 * without modification, are permitted provided that the following15 * conditions are met:16 *17 * - Redistributions of source code must retain the above18 * copyright notice, this list of conditions and the following19 * disclaimer.20 *21 * - Redistributions in binary form must reproduce the above22 * copyright notice, this list of conditions and the following23 * disclaimer in the documentation and/or other materials24 * provided with the distribution.25 *26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS30 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN31 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN32 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE33 * SOFTWARE.34 */35 36#include <linux/mm.h>37#include <linux/dma-mapping.h>38#include <linux/sched/signal.h>39#include <linux/sched/mm.h>40#include <linux/export.h>41#include <linux/slab.h>42#include <linux/pagemap.h>43#include <linux/count_zeros.h>44#include <rdma/ib_umem_odp.h>45 46#include "uverbs.h"47 48static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)49{50 bool make_dirty = umem->writable && dirty;51 struct scatterlist *sg;52 unsigned int i;53 54 if (dirty)55 ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt,56 DMA_BIDIRECTIONAL, 0);57 58 for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i)59 unpin_user_page_range_dirty_lock(sg_page(sg),60 DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty);61 62 sg_free_append_table(&umem->sgt_append);63}64 65/**66 * ib_umem_find_best_pgsz - Find best HW page size to use for this MR67 *68 * @umem: umem struct69 * @pgsz_bitmap: bitmap of HW supported page sizes70 * @virt: IOVA71 *72 * This helper is intended for HW that support multiple page73 * sizes but can do only a single page size in an MR.74 *75 * Returns 0 if the umem requires page sizes not supported by76 * the driver to be mapped. Drivers always supporting PAGE_SIZE77 * or smaller will never see a 0 result.78 */79unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,80 unsigned long pgsz_bitmap,81 unsigned long virt)82{83 struct scatterlist *sg;84 unsigned long va, pgoff;85 dma_addr_t mask;86 int i;87 88 umem->iova = va = virt;89 90 if (umem->is_odp) {91 unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift);92 93 /* ODP must always be self consistent. */94 if (!(pgsz_bitmap & page_size))95 return 0;96 return page_size;97 }98 99 /* The best result is the smallest page size that results in the minimum100 * number of required pages. Compute the largest page size that could101 * work based on VA address bits that don't change.102 */103 mask = pgsz_bitmap &104 GENMASK(BITS_PER_LONG - 1,105 bits_per((umem->length - 1 + virt) ^ virt));106 /* offset into first SGL */107 pgoff = umem->address & ~PAGE_MASK;108 109 for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {110 /* Walk SGL and reduce max page size if VA/PA bits differ111 * for any address.112 */113 mask |= (sg_dma_address(sg) + pgoff) ^ va;114 va += sg_dma_len(sg) - pgoff;115 /* Except for the last entry, the ending iova alignment sets116 * the maximum possible page size as the low bits of the iova117 * must be zero when starting the next chunk.118 */119 if (i != (umem->sgt_append.sgt.nents - 1))120 mask |= va;121 pgoff = 0;122 }123 124 /* The mask accumulates 1's in each position where the VA and physical125 * address differ, thus the length of trailing 0 is the largest page126 * size that can pass the VA through to the physical.127 */128 if (mask)129 pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0);130 return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0;131}132EXPORT_SYMBOL(ib_umem_find_best_pgsz);133 134/**135 * ib_umem_get - Pin and DMA map userspace memory.136 *137 * @device: IB device to connect UMEM138 * @addr: userspace virtual address to start at139 * @size: length of region to pin140 * @access: IB_ACCESS_xxx flags for memory being pinned141 */142struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,143 size_t size, int access)144{145 struct ib_umem *umem;146 struct page **page_list;147 unsigned long lock_limit;148 unsigned long new_pinned;149 unsigned long cur_base;150 unsigned long dma_attr = 0;151 struct mm_struct *mm;152 unsigned long npages;153 int pinned, ret;154 unsigned int gup_flags = FOLL_LONGTERM;155 156 /*157 * If the combination of the addr and size requested for this memory158 * region causes an integer overflow, return error.159 */160 if (((addr + size) < addr) ||161 PAGE_ALIGN(addr + size) < (addr + size))162 return ERR_PTR(-EINVAL);163 164 if (!can_do_mlock())165 return ERR_PTR(-EPERM);166 167 if (access & IB_ACCESS_ON_DEMAND)168 return ERR_PTR(-EOPNOTSUPP);169 170 umem = kzalloc(sizeof(*umem), GFP_KERNEL);171 if (!umem)172 return ERR_PTR(-ENOMEM);173 umem->ibdev = device;174 umem->length = size;175 umem->address = addr;176 /*177 * Drivers should call ib_umem_find_best_pgsz() to set the iova178 * correctly.179 */180 umem->iova = addr;181 umem->writable = ib_access_writable(access);182 umem->owning_mm = mm = current->mm;183 mmgrab(mm);184 185 page_list = (struct page **) __get_free_page(GFP_KERNEL);186 if (!page_list) {187 ret = -ENOMEM;188 goto umem_kfree;189 }190 191 npages = ib_umem_num_pages(umem);192 if (npages == 0 || npages > UINT_MAX) {193 ret = -EINVAL;194 goto out;195 }196 197 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;198 199 new_pinned = atomic64_add_return(npages, &mm->pinned_vm);200 if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {201 atomic64_sub(npages, &mm->pinned_vm);202 ret = -ENOMEM;203 goto out;204 }205 206 cur_base = addr & PAGE_MASK;207 208 if (umem->writable)209 gup_flags |= FOLL_WRITE;210 211 while (npages) {212 cond_resched();213 pinned = pin_user_pages_fast(cur_base,214 min_t(unsigned long, npages,215 PAGE_SIZE /216 sizeof(struct page *)),217 gup_flags, page_list);218 if (pinned < 0) {219 ret = pinned;220 goto umem_release;221 }222 223 cur_base += pinned * PAGE_SIZE;224 npages -= pinned;225 ret = sg_alloc_append_table_from_pages(226 &umem->sgt_append, page_list, pinned, 0,227 pinned << PAGE_SHIFT, ib_dma_max_seg_size(device),228 npages, GFP_KERNEL);229 if (ret) {230 unpin_user_pages_dirty_lock(page_list, pinned, 0);231 goto umem_release;232 }233 }234 235 if (access & IB_ACCESS_RELAXED_ORDERING)236 dma_attr |= DMA_ATTR_WEAK_ORDERING;237 238 ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt,239 DMA_BIDIRECTIONAL, dma_attr);240 if (ret)241 goto umem_release;242 goto out;243 244umem_release:245 __ib_umem_release(device, umem, 0);246 atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);247out:248 free_page((unsigned long) page_list);249umem_kfree:250 if (ret) {251 mmdrop(umem->owning_mm);252 kfree(umem);253 }254 return ret ? ERR_PTR(ret) : umem;255}256EXPORT_SYMBOL(ib_umem_get);257 258/**259 * ib_umem_release - release memory pinned with ib_umem_get260 * @umem: umem struct to release261 */262void ib_umem_release(struct ib_umem *umem)263{264 if (!umem)265 return;266 if (umem->is_dmabuf)267 return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));268 if (umem->is_odp)269 return ib_umem_odp_release(to_ib_umem_odp(umem));270 271 __ib_umem_release(umem->ibdev, umem, 1);272 273 atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);274 mmdrop(umem->owning_mm);275 kfree(umem);276}277EXPORT_SYMBOL(ib_umem_release);278 279/*280 * Copy from the given ib_umem's pages to the given buffer.281 *282 * umem - the umem to copy from283 * offset - offset to start copying from284 * dst - destination buffer285 * length - buffer length286 *287 * Returns 0 on success, or an error code.288 */289int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,290 size_t length)291{292 size_t end = offset + length;293 int ret;294 295 if (offset > umem->length || length > umem->length - offset) {296 pr_err("%s not in range. offset: %zd umem length: %zd end: %zd\n",297 __func__, offset, umem->length, end);298 return -EINVAL;299 }300 301 ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl,302 umem->sgt_append.sgt.orig_nents, dst, length,303 offset + ib_umem_offset(umem));304 305 if (ret < 0)306 return ret;307 else if (ret != length)308 return -EINVAL;309 else310 return 0;311}312EXPORT_SYMBOL(ib_umem_copy_from);313