1c942fddfSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 2133ff0eaSJérôme Glisse /* 3133ff0eaSJérôme Glisse * Copyright 2013 Red Hat Inc. 4133ff0eaSJérôme Glisse * 5f813f219SJérôme Glisse * Authors: Jérôme Glisse <jglisse@redhat.com> 6133ff0eaSJérôme Glisse */ 7133ff0eaSJérôme Glisse /* 8133ff0eaSJérôme Glisse * Refer to include/linux/hmm.h for information about heterogeneous memory 9133ff0eaSJérôme Glisse * management or HMM for short. 10133ff0eaSJérôme Glisse */ 11133ff0eaSJérôme Glisse #include <linux/mm.h> 12133ff0eaSJérôme Glisse #include <linux/hmm.h> 13858b54daSJérôme Glisse #include <linux/init.h> 14da4c3c73SJérôme Glisse #include <linux/rmap.h> 15da4c3c73SJérôme Glisse #include <linux/swap.h> 16133ff0eaSJérôme Glisse #include <linux/slab.h> 17133ff0eaSJérôme Glisse #include <linux/sched.h> 184ef589dcSJérôme Glisse #include <linux/mmzone.h> 194ef589dcSJérôme Glisse #include <linux/pagemap.h> 20da4c3c73SJérôme Glisse #include <linux/swapops.h> 21da4c3c73SJérôme Glisse #include <linux/hugetlb.h> 224ef589dcSJérôme Glisse #include <linux/memremap.h> 23*c8a53b2dSJason Gunthorpe #include <linux/sched/mm.h> 247b2d55d2SJérôme Glisse #include <linux/jump_label.h> 2555c0ece8SJérôme Glisse #include <linux/dma-mapping.h> 26c0b12405SJérôme Glisse #include <linux/mmu_notifier.h> 274ef589dcSJérôme Glisse #include <linux/memory_hotplug.h> 284ef589dcSJérôme Glisse 294ef589dcSJérôme Glisse #define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT) 30133ff0eaSJérôme Glisse 316b368cd4SJérôme Glisse #if IS_ENABLED(CONFIG_HMM_MIRROR) 32c0b12405SJérôme Glisse static const struct mmu_notifier_ops hmm_mmu_notifier_ops; 33c0b12405SJérôme Glisse 34704f3f2cSJérôme Glisse static inline struct hmm *mm_get_hmm(struct mm_struct *mm) 35133ff0eaSJérôme Glisse { 36c0b12405SJérôme Glisse struct hmm *hmm = READ_ONCE(mm->hmm); 37704f3f2cSJérôme Glisse 38704f3f2cSJérôme Glisse if (hmm && kref_get_unless_zero(&hmm->kref)) 39704f3f2cSJérôme Glisse return hmm; 40704f3f2cSJérôme Glisse 41704f3f2cSJérôme Glisse return NULL; 42704f3f2cSJérôme Glisse } 43704f3f2cSJérôme Glisse 44704f3f2cSJérôme Glisse /** 45704f3f2cSJérôme Glisse * hmm_get_or_create - register HMM against an mm (HMM internal) 46704f3f2cSJérôme Glisse * 47704f3f2cSJérôme Glisse * @mm: mm struct to attach to 48704f3f2cSJérôme Glisse * Returns: returns an HMM object, either by referencing the existing 49704f3f2cSJérôme Glisse * (per-process) object, or by creating a new one. 50704f3f2cSJérôme Glisse * 51704f3f2cSJérôme Glisse * This is not intended to be used directly by device drivers. If mm already 52704f3f2cSJérôme Glisse * has an HMM struct then it get a reference on it and returns it. Otherwise 53704f3f2cSJérôme Glisse * it allocates an HMM struct, initializes it, associate it with the mm and 54704f3f2cSJérôme Glisse * returns it. 55704f3f2cSJérôme Glisse */ 56704f3f2cSJérôme Glisse static struct hmm *hmm_get_or_create(struct mm_struct *mm) 57704f3f2cSJérôme Glisse { 58704f3f2cSJérôme Glisse struct hmm *hmm = mm_get_hmm(mm); 59c0b12405SJérôme Glisse bool cleanup = false; 60133ff0eaSJérôme Glisse 61c0b12405SJérôme Glisse if (hmm) 62c0b12405SJérôme Glisse return hmm; 63c0b12405SJérôme Glisse 64c0b12405SJérôme Glisse hmm = kmalloc(sizeof(*hmm), GFP_KERNEL); 65c0b12405SJérôme Glisse if (!hmm) 66c0b12405SJérôme Glisse return NULL; 67a3e0d41cSJérôme Glisse init_waitqueue_head(&hmm->wq); 68c0b12405SJérôme Glisse INIT_LIST_HEAD(&hmm->mirrors); 69c0b12405SJérôme Glisse init_rwsem(&hmm->mirrors_sem); 70c0b12405SJérôme Glisse hmm->mmu_notifier.ops = NULL; 71da4c3c73SJérôme Glisse INIT_LIST_HEAD(&hmm->ranges); 72a3e0d41cSJérôme Glisse mutex_init(&hmm->lock); 73704f3f2cSJérôme Glisse kref_init(&hmm->kref); 74a3e0d41cSJérôme Glisse hmm->notifiers = 0; 75a3e0d41cSJérôme Glisse hmm->dead = false; 76c0b12405SJérôme Glisse hmm->mm = mm; 77*c8a53b2dSJason Gunthorpe mmgrab(hmm->mm); 78c0b12405SJérôme Glisse 79c0b12405SJérôme Glisse spin_lock(&mm->page_table_lock); 80c0b12405SJérôme Glisse if (!mm->hmm) 81c0b12405SJérôme Glisse mm->hmm = hmm; 82c0b12405SJérôme Glisse else 83c0b12405SJérôme Glisse cleanup = true; 84c0b12405SJérôme Glisse spin_unlock(&mm->page_table_lock); 85c0b12405SJérôme Glisse 8686a2d598SRalph Campbell if (cleanup) 8786a2d598SRalph Campbell goto error; 8886a2d598SRalph Campbell 8986a2d598SRalph Campbell /* 9086a2d598SRalph Campbell * We should only get here if hold the mmap_sem in write mode ie on 9186a2d598SRalph Campbell * registration of first mirror through hmm_mirror_register() 9286a2d598SRalph Campbell */ 9386a2d598SRalph Campbell hmm->mmu_notifier.ops = &hmm_mmu_notifier_ops; 9486a2d598SRalph Campbell if (__mmu_notifier_register(&hmm->mmu_notifier, mm)) 9586a2d598SRalph Campbell goto error_mm; 96c0b12405SJérôme Glisse 97704f3f2cSJérôme Glisse return hmm; 9886a2d598SRalph Campbell 9986a2d598SRalph Campbell error_mm: 10086a2d598SRalph Campbell spin_lock(&mm->page_table_lock); 10186a2d598SRalph Campbell if (mm->hmm == hmm) 10286a2d598SRalph Campbell mm->hmm = NULL; 10386a2d598SRalph Campbell spin_unlock(&mm->page_table_lock); 10486a2d598SRalph Campbell error: 105*c8a53b2dSJason Gunthorpe mmdrop(hmm->mm); 10686a2d598SRalph Campbell kfree(hmm); 10786a2d598SRalph Campbell return NULL; 108133ff0eaSJérôme Glisse } 109133ff0eaSJérôme Glisse 1106d7c3cdeSJason Gunthorpe static void hmm_free_rcu(struct rcu_head *rcu) 1116d7c3cdeSJason Gunthorpe { 1126d7c3cdeSJason Gunthorpe kfree(container_of(rcu, struct hmm, rcu)); 1136d7c3cdeSJason Gunthorpe } 1146d7c3cdeSJason Gunthorpe 115704f3f2cSJérôme Glisse static void hmm_free(struct kref *kref) 116704f3f2cSJérôme Glisse { 117704f3f2cSJérôme Glisse struct hmm *hmm = container_of(kref, struct hmm, kref); 118704f3f2cSJérôme Glisse struct mm_struct *mm = hmm->mm; 119704f3f2cSJérôme Glisse 120704f3f2cSJérôme Glisse mmu_notifier_unregister_no_release(&hmm->mmu_notifier, mm); 121704f3f2cSJérôme Glisse 122704f3f2cSJérôme Glisse spin_lock(&mm->page_table_lock); 123704f3f2cSJérôme Glisse if (mm->hmm == hmm) 124704f3f2cSJérôme Glisse mm->hmm = NULL; 125704f3f2cSJérôme Glisse spin_unlock(&mm->page_table_lock); 126704f3f2cSJérôme Glisse 127*c8a53b2dSJason Gunthorpe mmdrop(hmm->mm); 1286d7c3cdeSJason Gunthorpe mmu_notifier_call_srcu(&hmm->rcu, hmm_free_rcu); 129704f3f2cSJérôme Glisse } 130704f3f2cSJérôme Glisse 131704f3f2cSJérôme Glisse static inline void hmm_put(struct hmm *hmm) 132704f3f2cSJérôme Glisse { 133704f3f2cSJérôme Glisse kref_put(&hmm->kref, hmm_free); 134704f3f2cSJérôme Glisse } 135704f3f2cSJérôme Glisse 136a3e0d41cSJérôme Glisse static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) 137c0b12405SJérôme Glisse { 1386d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 139c0b12405SJérôme Glisse struct hmm_mirror *mirror; 140da4c3c73SJérôme Glisse struct hmm_range *range; 141da4c3c73SJérôme Glisse 1426d7c3cdeSJason Gunthorpe /* Bail out if hmm is in the process of being freed */ 1436d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1446d7c3cdeSJason Gunthorpe return; 1456d7c3cdeSJason Gunthorpe 146a3e0d41cSJérôme Glisse /* Report this HMM as dying. */ 147a3e0d41cSJérôme Glisse hmm->dead = true; 148da4c3c73SJérôme Glisse 149a3e0d41cSJérôme Glisse /* Wake-up everyone waiting on any range. */ 150a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 151085ea250SRalph Campbell list_for_each_entry(range, &hmm->ranges, list) 152da4c3c73SJérôme Glisse range->valid = false; 153a3e0d41cSJérôme Glisse wake_up_all(&hmm->wq); 154a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 155e1401513SRalph Campbell 156e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 157e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, struct hmm_mirror, 158e1401513SRalph Campbell list); 159e1401513SRalph Campbell while (mirror) { 160e1401513SRalph Campbell list_del_init(&mirror->list); 161e1401513SRalph Campbell if (mirror->ops->release) { 162e1401513SRalph Campbell /* 163085ea250SRalph Campbell * Drop mirrors_sem so the release callback can wait 164085ea250SRalph Campbell * on any pending work that might itself trigger a 165085ea250SRalph Campbell * mmu_notifier callback and thus would deadlock with 166085ea250SRalph Campbell * us. 167e1401513SRalph Campbell */ 168e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 169e1401513SRalph Campbell mirror->ops->release(mirror); 170e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 171e1401513SRalph Campbell } 172e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, 173e1401513SRalph Campbell struct hmm_mirror, list); 174e1401513SRalph Campbell } 175e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 176704f3f2cSJérôme Glisse 177704f3f2cSJérôme Glisse hmm_put(hmm); 178e1401513SRalph Campbell } 179e1401513SRalph Campbell 18093065ac7SMichal Hocko static int hmm_invalidate_range_start(struct mmu_notifier *mn, 181a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 182c0b12405SJérôme Glisse { 1836d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 184a3e0d41cSJérôme Glisse struct hmm_mirror *mirror; 185ec131b2dSJérôme Glisse struct hmm_update update; 186a3e0d41cSJérôme Glisse struct hmm_range *range; 187a3e0d41cSJérôme Glisse int ret = 0; 188c0b12405SJérôme Glisse 1896d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1906d7c3cdeSJason Gunthorpe return 0; 191c0b12405SJérôme Glisse 192a3e0d41cSJérôme Glisse update.start = nrange->start; 193a3e0d41cSJérôme Glisse update.end = nrange->end; 194ec131b2dSJérôme Glisse update.event = HMM_UPDATE_INVALIDATE; 195dfcd6660SJérôme Glisse update.blockable = mmu_notifier_range_blockable(nrange); 196a3e0d41cSJérôme Glisse 197dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 198a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 199a3e0d41cSJérôme Glisse else if (!mutex_trylock(&hmm->lock)) { 200a3e0d41cSJérôme Glisse ret = -EAGAIN; 201a3e0d41cSJérôme Glisse goto out; 202a3e0d41cSJérôme Glisse } 203a3e0d41cSJérôme Glisse hmm->notifiers++; 204a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 205a3e0d41cSJérôme Glisse if (update.end < range->start || update.start >= range->end) 206a3e0d41cSJérôme Glisse continue; 207a3e0d41cSJérôme Glisse 208a3e0d41cSJérôme Glisse range->valid = false; 209a3e0d41cSJérôme Glisse } 210a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 211a3e0d41cSJérôme Glisse 212dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 213a3e0d41cSJérôme Glisse down_read(&hmm->mirrors_sem); 214a3e0d41cSJérôme Glisse else if (!down_read_trylock(&hmm->mirrors_sem)) { 215a3e0d41cSJérôme Glisse ret = -EAGAIN; 216a3e0d41cSJérôme Glisse goto out; 217a3e0d41cSJérôme Glisse } 218a3e0d41cSJérôme Glisse list_for_each_entry(mirror, &hmm->mirrors, list) { 219a3e0d41cSJérôme Glisse int ret; 220a3e0d41cSJérôme Glisse 221a3e0d41cSJérôme Glisse ret = mirror->ops->sync_cpu_device_pagetables(mirror, &update); 222085ea250SRalph Campbell if (!update.blockable && ret == -EAGAIN) 223085ea250SRalph Campbell break; 224a3e0d41cSJérôme Glisse } 225a3e0d41cSJérôme Glisse up_read(&hmm->mirrors_sem); 226a3e0d41cSJérôme Glisse 227a3e0d41cSJérôme Glisse out: 228704f3f2cSJérôme Glisse hmm_put(hmm); 229704f3f2cSJérôme Glisse return ret; 230c0b12405SJérôme Glisse } 231c0b12405SJérôme Glisse 232c0b12405SJérôme Glisse static void hmm_invalidate_range_end(struct mmu_notifier *mn, 233a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 234c0b12405SJérôme Glisse { 2356d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 236c0b12405SJérôme Glisse 2376d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 2386d7c3cdeSJason Gunthorpe return; 239c0b12405SJérôme Glisse 240a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 241a3e0d41cSJérôme Glisse hmm->notifiers--; 242a3e0d41cSJérôme Glisse if (!hmm->notifiers) { 243a3e0d41cSJérôme Glisse struct hmm_range *range; 244a3e0d41cSJérôme Glisse 245a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 246a3e0d41cSJérôme Glisse if (range->valid) 247a3e0d41cSJérôme Glisse continue; 248a3e0d41cSJérôme Glisse range->valid = true; 249a3e0d41cSJérôme Glisse } 250a3e0d41cSJérôme Glisse wake_up_all(&hmm->wq); 251a3e0d41cSJérôme Glisse } 252a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 253a3e0d41cSJérôme Glisse 254704f3f2cSJérôme Glisse hmm_put(hmm); 255c0b12405SJérôme Glisse } 256c0b12405SJérôme Glisse 257c0b12405SJérôme Glisse static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { 258e1401513SRalph Campbell .release = hmm_release, 259c0b12405SJérôme Glisse .invalidate_range_start = hmm_invalidate_range_start, 260c0b12405SJérôme Glisse .invalidate_range_end = hmm_invalidate_range_end, 261c0b12405SJérôme Glisse }; 262c0b12405SJérôme Glisse 263c0b12405SJérôme Glisse /* 264c0b12405SJérôme Glisse * hmm_mirror_register() - register a mirror against an mm 265c0b12405SJérôme Glisse * 266c0b12405SJérôme Glisse * @mirror: new mirror struct to register 267c0b12405SJérôme Glisse * @mm: mm to register against 268085ea250SRalph Campbell * Return: 0 on success, -ENOMEM if no memory, -EINVAL if invalid arguments 269c0b12405SJérôme Glisse * 270c0b12405SJérôme Glisse * To start mirroring a process address space, the device driver must register 271c0b12405SJérôme Glisse * an HMM mirror struct. 272c0b12405SJérôme Glisse * 273c0b12405SJérôme Glisse * THE mm->mmap_sem MUST BE HELD IN WRITE MODE ! 274c0b12405SJérôme Glisse */ 275c0b12405SJérôme Glisse int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm) 276c0b12405SJérôme Glisse { 277c0b12405SJérôme Glisse /* Sanity check */ 278c0b12405SJérôme Glisse if (!mm || !mirror || !mirror->ops) 279c0b12405SJérôme Glisse return -EINVAL; 280c0b12405SJérôme Glisse 281704f3f2cSJérôme Glisse mirror->hmm = hmm_get_or_create(mm); 282c0b12405SJérôme Glisse if (!mirror->hmm) 283c0b12405SJérôme Glisse return -ENOMEM; 284c0b12405SJérôme Glisse 285c0b12405SJérôme Glisse down_write(&mirror->hmm->mirrors_sem); 286c0b12405SJérôme Glisse list_add(&mirror->list, &mirror->hmm->mirrors); 287c0b12405SJérôme Glisse up_write(&mirror->hmm->mirrors_sem); 288c0b12405SJérôme Glisse 289c0b12405SJérôme Glisse return 0; 290c0b12405SJérôme Glisse } 291c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_register); 292c0b12405SJérôme Glisse 293c0b12405SJérôme Glisse /* 294c0b12405SJérôme Glisse * hmm_mirror_unregister() - unregister a mirror 295c0b12405SJérôme Glisse * 296085ea250SRalph Campbell * @mirror: mirror struct to unregister 297c0b12405SJérôme Glisse * 298c0b12405SJérôme Glisse * Stop mirroring a process address space, and cleanup. 299c0b12405SJérôme Glisse */ 300c0b12405SJérôme Glisse void hmm_mirror_unregister(struct hmm_mirror *mirror) 301c0b12405SJérôme Glisse { 302704f3f2cSJérôme Glisse struct hmm *hmm = READ_ONCE(mirror->hmm); 303c0b12405SJérôme Glisse 304704f3f2cSJérôme Glisse if (hmm == NULL) 305c01cbba2SJérôme Glisse return; 306c01cbba2SJérôme Glisse 307c0b12405SJérôme Glisse down_write(&hmm->mirrors_sem); 308e1401513SRalph Campbell list_del_init(&mirror->list); 309704f3f2cSJérôme Glisse /* To protect us against double unregister ... */ 310c01cbba2SJérôme Glisse mirror->hmm = NULL; 311c0b12405SJérôme Glisse up_write(&hmm->mirrors_sem); 312c01cbba2SJérôme Glisse 313704f3f2cSJérôme Glisse hmm_put(hmm); 314c0b12405SJérôme Glisse } 315c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_unregister); 316da4c3c73SJérôme Glisse 31774eee180SJérôme Glisse struct hmm_vma_walk { 31874eee180SJérôme Glisse struct hmm_range *range; 319992de9a8SJérôme Glisse struct dev_pagemap *pgmap; 32074eee180SJérôme Glisse unsigned long last; 32174eee180SJérôme Glisse bool fault; 32274eee180SJérôme Glisse bool block; 32374eee180SJérôme Glisse }; 32474eee180SJérôme Glisse 3252aee09d8SJérôme Glisse static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr, 3262aee09d8SJérôme Glisse bool write_fault, uint64_t *pfn) 32774eee180SJérôme Glisse { 3289b1ae605SKuehling, Felix unsigned int flags = FAULT_FLAG_REMOTE; 32974eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 330f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 33174eee180SJérôme Glisse struct vm_area_struct *vma = walk->vma; 33250a7ca3cSSouptick Joarder vm_fault_t ret; 33374eee180SJérôme Glisse 33474eee180SJérôme Glisse flags |= hmm_vma_walk->block ? 0 : FAULT_FLAG_ALLOW_RETRY; 3352aee09d8SJérôme Glisse flags |= write_fault ? FAULT_FLAG_WRITE : 0; 33650a7ca3cSSouptick Joarder ret = handle_mm_fault(vma, addr, flags); 33750a7ca3cSSouptick Joarder if (ret & VM_FAULT_RETRY) 33873231612SJérôme Glisse return -EAGAIN; 33950a7ca3cSSouptick Joarder if (ret & VM_FAULT_ERROR) { 340f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 34174eee180SJérôme Glisse return -EFAULT; 34274eee180SJérôme Glisse } 34374eee180SJérôme Glisse 34473231612SJérôme Glisse return -EBUSY; 34574eee180SJérôme Glisse } 34674eee180SJérôme Glisse 347da4c3c73SJérôme Glisse static int hmm_pfns_bad(unsigned long addr, 348da4c3c73SJérôme Glisse unsigned long end, 349da4c3c73SJérôme Glisse struct mm_walk *walk) 350da4c3c73SJérôme Glisse { 351c719547fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 352c719547fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 353ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 354da4c3c73SJérôme Glisse unsigned long i; 355da4c3c73SJérôme Glisse 356da4c3c73SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 357da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, i++) 358f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_ERROR]; 359da4c3c73SJérôme Glisse 360da4c3c73SJérôme Glisse return 0; 361da4c3c73SJérôme Glisse } 362da4c3c73SJérôme Glisse 3635504ed29SJérôme Glisse /* 3645504ed29SJérôme Glisse * hmm_vma_walk_hole() - handle a range lacking valid pmd or pte(s) 3655504ed29SJérôme Glisse * @start: range virtual start address (inclusive) 3665504ed29SJérôme Glisse * @end: range virtual end address (exclusive) 3672aee09d8SJérôme Glisse * @fault: should we fault or not ? 3682aee09d8SJérôme Glisse * @write_fault: write fault ? 3695504ed29SJérôme Glisse * @walk: mm_walk structure 370085ea250SRalph Campbell * Return: 0 on success, -EBUSY after page fault, or page fault error 3715504ed29SJérôme Glisse * 3725504ed29SJérôme Glisse * This function will be called whenever pmd_none() or pte_none() returns true, 3735504ed29SJérôme Glisse * or whenever there is no page directory covering the virtual address range. 3745504ed29SJérôme Glisse */ 3752aee09d8SJérôme Glisse static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end, 3762aee09d8SJérôme Glisse bool fault, bool write_fault, 377da4c3c73SJérôme Glisse struct mm_walk *walk) 378da4c3c73SJérôme Glisse { 37974eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 38074eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 381ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 38263d5066fSJérôme Glisse unsigned long i, page_size; 383da4c3c73SJérôme Glisse 38474eee180SJérôme Glisse hmm_vma_walk->last = addr; 38563d5066fSJérôme Glisse page_size = hmm_range_page_size(range); 38663d5066fSJérôme Glisse i = (addr - range->start) >> range->page_shift; 38763d5066fSJérôme Glisse 38863d5066fSJérôme Glisse for (; addr < end; addr += page_size, i++) { 389f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_NONE]; 3902aee09d8SJérôme Glisse if (fault || write_fault) { 39174eee180SJérôme Glisse int ret; 392da4c3c73SJérôme Glisse 3932aee09d8SJérôme Glisse ret = hmm_vma_do_fault(walk, addr, write_fault, 3942aee09d8SJérôme Glisse &pfns[i]); 39573231612SJérôme Glisse if (ret != -EBUSY) 39674eee180SJérôme Glisse return ret; 39774eee180SJérôme Glisse } 39874eee180SJérôme Glisse } 39974eee180SJérôme Glisse 40073231612SJérôme Glisse return (fault || write_fault) ? -EBUSY : 0; 4012aee09d8SJérôme Glisse } 4022aee09d8SJérôme Glisse 4032aee09d8SJérôme Glisse static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 4042aee09d8SJérôme Glisse uint64_t pfns, uint64_t cpu_flags, 4052aee09d8SJérôme Glisse bool *fault, bool *write_fault) 4062aee09d8SJérôme Glisse { 407f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 408f88a1e90SJérôme Glisse 4092aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) 4102aee09d8SJérôme Glisse return; 4112aee09d8SJérôme Glisse 412023a019aSJérôme Glisse /* 413023a019aSJérôme Glisse * So we not only consider the individual per page request we also 414023a019aSJérôme Glisse * consider the default flags requested for the range. The API can 415023a019aSJérôme Glisse * be use in 2 fashions. The first one where the HMM user coalesce 416023a019aSJérôme Glisse * multiple page fault into one request and set flags per pfns for 417023a019aSJérôme Glisse * of those faults. The second one where the HMM user want to pre- 418023a019aSJérôme Glisse * fault a range with specific flags. For the latter one it is a 419023a019aSJérôme Glisse * waste to have the user pre-fill the pfn arrays with a default 420023a019aSJérôme Glisse * flags value. 421023a019aSJérôme Glisse */ 422023a019aSJérôme Glisse pfns = (pfns & range->pfn_flags_mask) | range->default_flags; 423023a019aSJérôme Glisse 4242aee09d8SJérôme Glisse /* We aren't ask to do anything ... */ 425f88a1e90SJérôme Glisse if (!(pfns & range->flags[HMM_PFN_VALID])) 4262aee09d8SJérôme Glisse return; 427f88a1e90SJérôme Glisse /* If this is device memory than only fault if explicitly requested */ 428f88a1e90SJérôme Glisse if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) { 429f88a1e90SJérôme Glisse /* Do we fault on device memory ? */ 430f88a1e90SJérôme Glisse if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) { 431f88a1e90SJérôme Glisse *write_fault = pfns & range->flags[HMM_PFN_WRITE]; 432f88a1e90SJérôme Glisse *fault = true; 433f88a1e90SJérôme Glisse } 4342aee09d8SJérôme Glisse return; 4352aee09d8SJérôme Glisse } 436f88a1e90SJérôme Glisse 437f88a1e90SJérôme Glisse /* If CPU page table is not valid then we need to fault */ 438f88a1e90SJérôme Glisse *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]); 439f88a1e90SJérôme Glisse /* Need to write fault ? */ 440f88a1e90SJérôme Glisse if ((pfns & range->flags[HMM_PFN_WRITE]) && 441f88a1e90SJérôme Glisse !(cpu_flags & range->flags[HMM_PFN_WRITE])) { 442f88a1e90SJérôme Glisse *write_fault = true; 4432aee09d8SJérôme Glisse *fault = true; 4442aee09d8SJérôme Glisse } 4452aee09d8SJérôme Glisse } 4462aee09d8SJérôme Glisse 4472aee09d8SJérôme Glisse static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 4482aee09d8SJérôme Glisse const uint64_t *pfns, unsigned long npages, 4492aee09d8SJérôme Glisse uint64_t cpu_flags, bool *fault, 4502aee09d8SJérôme Glisse bool *write_fault) 4512aee09d8SJérôme Glisse { 4522aee09d8SJérôme Glisse unsigned long i; 4532aee09d8SJérôme Glisse 4542aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) { 4552aee09d8SJérôme Glisse *fault = *write_fault = false; 4562aee09d8SJérôme Glisse return; 4572aee09d8SJérôme Glisse } 4582aee09d8SJérôme Glisse 459a3e0d41cSJérôme Glisse *fault = *write_fault = false; 4602aee09d8SJérôme Glisse for (i = 0; i < npages; ++i) { 4612aee09d8SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags, 4622aee09d8SJérôme Glisse fault, write_fault); 463a3e0d41cSJérôme Glisse if ((*write_fault)) 4642aee09d8SJérôme Glisse return; 4652aee09d8SJérôme Glisse } 4662aee09d8SJérôme Glisse } 4672aee09d8SJérôme Glisse 4682aee09d8SJérôme Glisse static int hmm_vma_walk_hole(unsigned long addr, unsigned long end, 4692aee09d8SJérôme Glisse struct mm_walk *walk) 4702aee09d8SJérôme Glisse { 4712aee09d8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 4722aee09d8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 4732aee09d8SJérôme Glisse bool fault, write_fault; 4742aee09d8SJérôme Glisse unsigned long i, npages; 4752aee09d8SJérôme Glisse uint64_t *pfns; 4762aee09d8SJérôme Glisse 4772aee09d8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 4782aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 4792aee09d8SJérôme Glisse pfns = &range->pfns[i]; 4802aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 4812aee09d8SJérôme Glisse 0, &fault, &write_fault); 4822aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 4832aee09d8SJérôme Glisse } 4842aee09d8SJérôme Glisse 485f88a1e90SJérôme Glisse static inline uint64_t pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd) 4862aee09d8SJérôme Glisse { 4872aee09d8SJérôme Glisse if (pmd_protnone(pmd)) 4882aee09d8SJérôme Glisse return 0; 489f88a1e90SJérôme Glisse return pmd_write(pmd) ? range->flags[HMM_PFN_VALID] | 490f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 491f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 492da4c3c73SJérôme Glisse } 493da4c3c73SJérôme Glisse 494992de9a8SJérôme Glisse static inline uint64_t pud_to_hmm_pfn_flags(struct hmm_range *range, pud_t pud) 495992de9a8SJérôme Glisse { 496992de9a8SJérôme Glisse if (!pud_present(pud)) 497992de9a8SJérôme Glisse return 0; 498992de9a8SJérôme Glisse return pud_write(pud) ? range->flags[HMM_PFN_VALID] | 499992de9a8SJérôme Glisse range->flags[HMM_PFN_WRITE] : 500992de9a8SJérôme Glisse range->flags[HMM_PFN_VALID]; 501992de9a8SJérôme Glisse } 502992de9a8SJérôme Glisse 50353f5c3f4SJérôme Glisse static int hmm_vma_handle_pmd(struct mm_walk *walk, 50453f5c3f4SJérôme Glisse unsigned long addr, 50553f5c3f4SJérôme Glisse unsigned long end, 50653f5c3f4SJérôme Glisse uint64_t *pfns, 50753f5c3f4SJérôme Glisse pmd_t pmd) 50853f5c3f4SJérôme Glisse { 509992de9a8SJérôme Glisse #ifdef CONFIG_TRANSPARENT_HUGEPAGE 51053f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 511f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 5122aee09d8SJérôme Glisse unsigned long pfn, npages, i; 5132aee09d8SJérôme Glisse bool fault, write_fault; 514f88a1e90SJérôme Glisse uint64_t cpu_flags; 51553f5c3f4SJérôme Glisse 5162aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 517f88a1e90SJérôme Glisse cpu_flags = pmd_to_hmm_pfn_flags(range, pmd); 5182aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags, 5192aee09d8SJérôme Glisse &fault, &write_fault); 52053f5c3f4SJérôme Glisse 5212aee09d8SJérôme Glisse if (pmd_protnone(pmd) || fault || write_fault) 5222aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 52353f5c3f4SJérôme Glisse 52453f5c3f4SJérôme Glisse pfn = pmd_pfn(pmd) + pte_index(addr); 525992de9a8SJérôme Glisse for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { 526992de9a8SJérôme Glisse if (pmd_devmap(pmd)) { 527992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 528992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 529992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 530992de9a8SJérôme Glisse return -EBUSY; 531992de9a8SJérôme Glisse } 532391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; 533992de9a8SJérôme Glisse } 534992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 535992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 536992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 537992de9a8SJérôme Glisse } 53853f5c3f4SJérôme Glisse hmm_vma_walk->last = end; 53953f5c3f4SJérôme Glisse return 0; 540992de9a8SJérôme Glisse #else 541992de9a8SJérôme Glisse /* If THP is not enabled then we should never reach that code ! */ 542992de9a8SJérôme Glisse return -EINVAL; 543992de9a8SJérôme Glisse #endif 54453f5c3f4SJérôme Glisse } 54553f5c3f4SJérôme Glisse 546f88a1e90SJérôme Glisse static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte) 5472aee09d8SJérôme Glisse { 548789c2af8SPhilip Yang if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte)) 5492aee09d8SJérôme Glisse return 0; 550f88a1e90SJérôme Glisse return pte_write(pte) ? range->flags[HMM_PFN_VALID] | 551f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 552f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 5532aee09d8SJérôme Glisse } 5542aee09d8SJérôme Glisse 55553f5c3f4SJérôme Glisse static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, 55653f5c3f4SJérôme Glisse unsigned long end, pmd_t *pmdp, pte_t *ptep, 55753f5c3f4SJérôme Glisse uint64_t *pfn) 55853f5c3f4SJérôme Glisse { 55953f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 560f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 56153f5c3f4SJérôme Glisse struct vm_area_struct *vma = walk->vma; 5622aee09d8SJérôme Glisse bool fault, write_fault; 5632aee09d8SJérôme Glisse uint64_t cpu_flags; 56453f5c3f4SJérôme Glisse pte_t pte = *ptep; 565f88a1e90SJérôme Glisse uint64_t orig_pfn = *pfn; 56653f5c3f4SJérôme Glisse 567f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_NONE]; 56873231612SJérôme Glisse fault = write_fault = false; 56953f5c3f4SJérôme Glisse 57053f5c3f4SJérôme Glisse if (pte_none(pte)) { 57173231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, 57273231612SJérôme Glisse &fault, &write_fault); 5732aee09d8SJérôme Glisse if (fault || write_fault) 57453f5c3f4SJérôme Glisse goto fault; 57553f5c3f4SJérôme Glisse return 0; 57653f5c3f4SJérôme Glisse } 57753f5c3f4SJérôme Glisse 57853f5c3f4SJérôme Glisse if (!pte_present(pte)) { 57953f5c3f4SJérôme Glisse swp_entry_t entry = pte_to_swp_entry(pte); 58053f5c3f4SJérôme Glisse 58153f5c3f4SJérôme Glisse if (!non_swap_entry(entry)) { 5822aee09d8SJérôme Glisse if (fault || write_fault) 58353f5c3f4SJérôme Glisse goto fault; 58453f5c3f4SJérôme Glisse return 0; 58553f5c3f4SJérôme Glisse } 58653f5c3f4SJérôme Glisse 58753f5c3f4SJérôme Glisse /* 58853f5c3f4SJérôme Glisse * This is a special swap entry, ignore migration, use 58953f5c3f4SJérôme Glisse * device and report anything else as error. 59053f5c3f4SJérôme Glisse */ 59153f5c3f4SJérôme Glisse if (is_device_private_entry(entry)) { 592f88a1e90SJérôme Glisse cpu_flags = range->flags[HMM_PFN_VALID] | 593f88a1e90SJérôme Glisse range->flags[HMM_PFN_DEVICE_PRIVATE]; 5942aee09d8SJérôme Glisse cpu_flags |= is_write_device_private_entry(entry) ? 595f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 0; 596f88a1e90SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 597f88a1e90SJérôme Glisse &fault, &write_fault); 598f88a1e90SJérôme Glisse if (fault || write_fault) 599f88a1e90SJérôme Glisse goto fault; 600391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, 601391aab11SJérôme Glisse swp_offset(entry)); 602f88a1e90SJérôme Glisse *pfn |= cpu_flags; 60353f5c3f4SJérôme Glisse return 0; 60453f5c3f4SJérôme Glisse } 60553f5c3f4SJérôme Glisse 60653f5c3f4SJérôme Glisse if (is_migration_entry(entry)) { 6072aee09d8SJérôme Glisse if (fault || write_fault) { 60853f5c3f4SJérôme Glisse pte_unmap(ptep); 60953f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 61053f5c3f4SJérôme Glisse migration_entry_wait(vma->vm_mm, 61153f5c3f4SJérôme Glisse pmdp, addr); 61273231612SJérôme Glisse return -EBUSY; 61353f5c3f4SJérôme Glisse } 61453f5c3f4SJérôme Glisse return 0; 61553f5c3f4SJérôme Glisse } 61653f5c3f4SJérôme Glisse 61753f5c3f4SJérôme Glisse /* Report error for everything else */ 618f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 61953f5c3f4SJérôme Glisse return -EFAULT; 62073231612SJérôme Glisse } else { 62173231612SJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, pte); 62273231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 62373231612SJérôme Glisse &fault, &write_fault); 62453f5c3f4SJérôme Glisse } 62553f5c3f4SJérôme Glisse 6262aee09d8SJérôme Glisse if (fault || write_fault) 62753f5c3f4SJérôme Glisse goto fault; 62853f5c3f4SJérôme Glisse 629992de9a8SJérôme Glisse if (pte_devmap(pte)) { 630992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pte_pfn(pte), 631992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 632992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 633992de9a8SJérôme Glisse return -EBUSY; 634992de9a8SJérôme Glisse } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) { 635992de9a8SJérôme Glisse *pfn = range->values[HMM_PFN_SPECIAL]; 636992de9a8SJérôme Glisse return -EFAULT; 637992de9a8SJérôme Glisse } 638992de9a8SJérôme Glisse 639391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags; 64053f5c3f4SJérôme Glisse return 0; 64153f5c3f4SJérôme Glisse 64253f5c3f4SJérôme Glisse fault: 643992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 644992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 645992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 646992de9a8SJérôme Glisse } 64753f5c3f4SJérôme Glisse pte_unmap(ptep); 64853f5c3f4SJérôme Glisse /* Fault any virtual address we were asked to fault */ 6492aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 65053f5c3f4SJérôme Glisse } 65153f5c3f4SJérôme Glisse 652da4c3c73SJérôme Glisse static int hmm_vma_walk_pmd(pmd_t *pmdp, 653da4c3c73SJérôme Glisse unsigned long start, 654da4c3c73SJérôme Glisse unsigned long end, 655da4c3c73SJérôme Glisse struct mm_walk *walk) 656da4c3c73SJérôme Glisse { 65774eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 65874eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 659d08faca0SJérôme Glisse struct vm_area_struct *vma = walk->vma; 660ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 661da4c3c73SJérôme Glisse unsigned long addr = start, i; 662da4c3c73SJérôme Glisse pte_t *ptep; 663da4c3c73SJérôme Glisse pmd_t pmd; 664da4c3c73SJérôme Glisse 665d08faca0SJérôme Glisse 666d08faca0SJérôme Glisse again: 667d08faca0SJérôme Glisse pmd = READ_ONCE(*pmdp); 668d08faca0SJérôme Glisse if (pmd_none(pmd)) 669d08faca0SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 670d08faca0SJérôme Glisse 671d08faca0SJérôme Glisse if (pmd_huge(pmd) && (range->vma->vm_flags & VM_HUGETLB)) 672d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 673d08faca0SJérôme Glisse 674d08faca0SJérôme Glisse if (thp_migration_supported() && is_pmd_migration_entry(pmd)) { 675d08faca0SJérôme Glisse bool fault, write_fault; 676d08faca0SJérôme Glisse unsigned long npages; 677d08faca0SJérôme Glisse uint64_t *pfns; 678d08faca0SJérôme Glisse 679d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 680d08faca0SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 681d08faca0SJérôme Glisse pfns = &range->pfns[i]; 682d08faca0SJérôme Glisse 683d08faca0SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 684d08faca0SJérôme Glisse 0, &fault, &write_fault); 685d08faca0SJérôme Glisse if (fault || write_fault) { 686d08faca0SJérôme Glisse hmm_vma_walk->last = addr; 687d08faca0SJérôme Glisse pmd_migration_entry_wait(vma->vm_mm, pmdp); 68873231612SJérôme Glisse return -EBUSY; 689d08faca0SJérôme Glisse } 690d08faca0SJérôme Glisse return 0; 691d08faca0SJérôme Glisse } else if (!pmd_present(pmd)) 692d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 693d08faca0SJérôme Glisse 694d08faca0SJérôme Glisse if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) { 695da4c3c73SJérôme Glisse /* 696da4c3c73SJérôme Glisse * No need to take pmd_lock here, even if some other threads 697da4c3c73SJérôme Glisse * is splitting the huge pmd we will get that event through 698da4c3c73SJérôme Glisse * mmu_notifier callback. 699da4c3c73SJérôme Glisse * 700da4c3c73SJérôme Glisse * So just read pmd value and check again its a transparent 701da4c3c73SJérôme Glisse * huge or device mapping one and compute corresponding pfn 702da4c3c73SJérôme Glisse * values. 703da4c3c73SJérôme Glisse */ 704da4c3c73SJérôme Glisse pmd = pmd_read_atomic(pmdp); 705da4c3c73SJérôme Glisse barrier(); 706da4c3c73SJérôme Glisse if (!pmd_devmap(pmd) && !pmd_trans_huge(pmd)) 707da4c3c73SJérôme Glisse goto again; 708da4c3c73SJérôme Glisse 709d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 71053f5c3f4SJérôme Glisse return hmm_vma_handle_pmd(walk, addr, end, &pfns[i], pmd); 711da4c3c73SJérôme Glisse } 712da4c3c73SJérôme Glisse 713d08faca0SJérôme Glisse /* 714d08faca0SJérôme Glisse * We have handled all the valid case above ie either none, migration, 715d08faca0SJérôme Glisse * huge or transparent huge. At this point either it is a valid pmd 716d08faca0SJérôme Glisse * entry pointing to pte directory or it is a bad pmd that will not 717d08faca0SJérôme Glisse * recover. 718d08faca0SJérôme Glisse */ 719d08faca0SJérôme Glisse if (pmd_bad(pmd)) 720da4c3c73SJérôme Glisse return hmm_pfns_bad(start, end, walk); 721da4c3c73SJérôme Glisse 722da4c3c73SJérôme Glisse ptep = pte_offset_map(pmdp, addr); 723d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 724da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, ptep++, i++) { 72553f5c3f4SJérôme Glisse int r; 726da4c3c73SJérôme Glisse 72753f5c3f4SJérôme Glisse r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, &pfns[i]); 72853f5c3f4SJérôme Glisse if (r) { 72953f5c3f4SJérôme Glisse /* hmm_vma_handle_pte() did unmap pte directory */ 73074eee180SJérôme Glisse hmm_vma_walk->last = addr; 73153f5c3f4SJérôme Glisse return r; 73274eee180SJérôme Glisse } 733da4c3c73SJérôme Glisse } 734992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 735992de9a8SJérôme Glisse /* 736992de9a8SJérôme Glisse * We do put_dev_pagemap() here and not in hmm_vma_handle_pte() 737992de9a8SJérôme Glisse * so that we can leverage get_dev_pagemap() optimization which 738992de9a8SJérôme Glisse * will not re-take a reference on a pgmap if we already have 739992de9a8SJérôme Glisse * one. 740992de9a8SJérôme Glisse */ 741992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 742992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 743992de9a8SJérôme Glisse } 744da4c3c73SJérôme Glisse pte_unmap(ptep - 1); 745da4c3c73SJérôme Glisse 74653f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 747da4c3c73SJérôme Glisse return 0; 748da4c3c73SJérôme Glisse } 749da4c3c73SJérôme Glisse 750992de9a8SJérôme Glisse static int hmm_vma_walk_pud(pud_t *pudp, 751992de9a8SJérôme Glisse unsigned long start, 752992de9a8SJérôme Glisse unsigned long end, 753992de9a8SJérôme Glisse struct mm_walk *walk) 754992de9a8SJérôme Glisse { 755992de9a8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 756992de9a8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 757992de9a8SJérôme Glisse unsigned long addr = start, next; 758992de9a8SJérôme Glisse pmd_t *pmdp; 759992de9a8SJérôme Glisse pud_t pud; 760992de9a8SJérôme Glisse int ret; 761992de9a8SJérôme Glisse 762992de9a8SJérôme Glisse again: 763992de9a8SJérôme Glisse pud = READ_ONCE(*pudp); 764992de9a8SJérôme Glisse if (pud_none(pud)) 765992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 766992de9a8SJérôme Glisse 767992de9a8SJérôme Glisse if (pud_huge(pud) && pud_devmap(pud)) { 768992de9a8SJérôme Glisse unsigned long i, npages, pfn; 769992de9a8SJérôme Glisse uint64_t *pfns, cpu_flags; 770992de9a8SJérôme Glisse bool fault, write_fault; 771992de9a8SJérôme Glisse 772992de9a8SJérôme Glisse if (!pud_present(pud)) 773992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 774992de9a8SJérôme Glisse 775992de9a8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 776992de9a8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 777992de9a8SJérôme Glisse pfns = &range->pfns[i]; 778992de9a8SJérôme Glisse 779992de9a8SJérôme Glisse cpu_flags = pud_to_hmm_pfn_flags(range, pud); 780992de9a8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 781992de9a8SJérôme Glisse cpu_flags, &fault, &write_fault); 782992de9a8SJérôme Glisse if (fault || write_fault) 783992de9a8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, 784992de9a8SJérôme Glisse write_fault, walk); 785992de9a8SJérôme Glisse 786992de9a8SJérôme Glisse pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); 787992de9a8SJérôme Glisse for (i = 0; i < npages; ++i, ++pfn) { 788992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 789992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 790992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 791992de9a8SJérôme Glisse return -EBUSY; 792391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 793391aab11SJérôme Glisse cpu_flags; 794992de9a8SJérôme Glisse } 795992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 796992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 797992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 798992de9a8SJérôme Glisse } 799992de9a8SJérôme Glisse hmm_vma_walk->last = end; 800992de9a8SJérôme Glisse return 0; 801992de9a8SJérôme Glisse } 802992de9a8SJérôme Glisse 803992de9a8SJérôme Glisse split_huge_pud(walk->vma, pudp, addr); 804992de9a8SJérôme Glisse if (pud_none(*pudp)) 805992de9a8SJérôme Glisse goto again; 806992de9a8SJérôme Glisse 807992de9a8SJérôme Glisse pmdp = pmd_offset(pudp, addr); 808992de9a8SJérôme Glisse do { 809992de9a8SJérôme Glisse next = pmd_addr_end(addr, end); 810992de9a8SJérôme Glisse ret = hmm_vma_walk_pmd(pmdp, addr, next, walk); 811992de9a8SJérôme Glisse if (ret) 812992de9a8SJérôme Glisse return ret; 813992de9a8SJérôme Glisse } while (pmdp++, addr = next, addr != end); 814992de9a8SJérôme Glisse 815992de9a8SJérôme Glisse return 0; 816992de9a8SJérôme Glisse } 817992de9a8SJérôme Glisse 81863d5066fSJérôme Glisse static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, 81963d5066fSJérôme Glisse unsigned long start, unsigned long end, 82063d5066fSJérôme Glisse struct mm_walk *walk) 82163d5066fSJérôme Glisse { 82263d5066fSJérôme Glisse #ifdef CONFIG_HUGETLB_PAGE 82363d5066fSJérôme Glisse unsigned long addr = start, i, pfn, mask, size, pfn_inc; 82463d5066fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 82563d5066fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 82663d5066fSJérôme Glisse struct vm_area_struct *vma = walk->vma; 82763d5066fSJérôme Glisse struct hstate *h = hstate_vma(vma); 82863d5066fSJérôme Glisse uint64_t orig_pfn, cpu_flags; 82963d5066fSJérôme Glisse bool fault, write_fault; 83063d5066fSJérôme Glisse spinlock_t *ptl; 83163d5066fSJérôme Glisse pte_t entry; 83263d5066fSJérôme Glisse int ret = 0; 83363d5066fSJérôme Glisse 83463d5066fSJérôme Glisse size = 1UL << huge_page_shift(h); 83563d5066fSJérôme Glisse mask = size - 1; 83663d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) { 83763d5066fSJérôme Glisse /* Make sure we are looking at full page. */ 83863d5066fSJérôme Glisse if (start & mask) 83963d5066fSJérôme Glisse return -EINVAL; 84063d5066fSJérôme Glisse if (end < (start + size)) 84163d5066fSJérôme Glisse return -EINVAL; 84263d5066fSJérôme Glisse pfn_inc = size >> PAGE_SHIFT; 84363d5066fSJérôme Glisse } else { 84463d5066fSJérôme Glisse pfn_inc = 1; 84563d5066fSJérôme Glisse size = PAGE_SIZE; 84663d5066fSJérôme Glisse } 84763d5066fSJérôme Glisse 84863d5066fSJérôme Glisse 84963d5066fSJérôme Glisse ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); 85063d5066fSJérôme Glisse entry = huge_ptep_get(pte); 85163d5066fSJérôme Glisse 85263d5066fSJérôme Glisse i = (start - range->start) >> range->page_shift; 85363d5066fSJérôme Glisse orig_pfn = range->pfns[i]; 85463d5066fSJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 85563d5066fSJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, entry); 85663d5066fSJérôme Glisse fault = write_fault = false; 85763d5066fSJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 85863d5066fSJérôme Glisse &fault, &write_fault); 85963d5066fSJérôme Glisse if (fault || write_fault) { 86063d5066fSJérôme Glisse ret = -ENOENT; 86163d5066fSJérôme Glisse goto unlock; 86263d5066fSJérôme Glisse } 86363d5066fSJérôme Glisse 86463d5066fSJérôme Glisse pfn = pte_pfn(entry) + ((start & mask) >> range->page_shift); 86563d5066fSJérôme Glisse for (; addr < end; addr += size, i++, pfn += pfn_inc) 866391aab11SJérôme Glisse range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 867391aab11SJérôme Glisse cpu_flags; 86863d5066fSJérôme Glisse hmm_vma_walk->last = end; 86963d5066fSJérôme Glisse 87063d5066fSJérôme Glisse unlock: 87163d5066fSJérôme Glisse spin_unlock(ptl); 87263d5066fSJérôme Glisse 87363d5066fSJérôme Glisse if (ret == -ENOENT) 87463d5066fSJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 87563d5066fSJérôme Glisse 87663d5066fSJérôme Glisse return ret; 87763d5066fSJérôme Glisse #else /* CONFIG_HUGETLB_PAGE */ 87863d5066fSJérôme Glisse return -EINVAL; 87963d5066fSJérôme Glisse #endif 88063d5066fSJérôme Glisse } 88163d5066fSJérôme Glisse 882f88a1e90SJérôme Glisse static void hmm_pfns_clear(struct hmm_range *range, 883f88a1e90SJérôme Glisse uint64_t *pfns, 88433cd47dcSJérôme Glisse unsigned long addr, 88533cd47dcSJérôme Glisse unsigned long end) 88633cd47dcSJérôme Glisse { 88733cd47dcSJérôme Glisse for (; addr < end; addr += PAGE_SIZE, pfns++) 888f88a1e90SJérôme Glisse *pfns = range->values[HMM_PFN_NONE]; 88933cd47dcSJérôme Glisse } 89033cd47dcSJérôme Glisse 891da4c3c73SJérôme Glisse /* 892a3e0d41cSJérôme Glisse * hmm_range_register() - start tracking change to CPU page table over a range 893a3e0d41cSJérôme Glisse * @range: range 894a3e0d41cSJérôme Glisse * @mm: the mm struct for the range of virtual address 895a3e0d41cSJérôme Glisse * @start: start virtual address (inclusive) 896a3e0d41cSJérôme Glisse * @end: end virtual address (exclusive) 89763d5066fSJérôme Glisse * @page_shift: expect page shift for the range 898a3e0d41cSJérôme Glisse * Returns 0 on success, -EFAULT if the address space is no longer valid 899a3e0d41cSJérôme Glisse * 900a3e0d41cSJérôme Glisse * Track updates to the CPU page table see include/linux/hmm.h 901a3e0d41cSJérôme Glisse */ 902a3e0d41cSJérôme Glisse int hmm_range_register(struct hmm_range *range, 903e36acfe6SJason Gunthorpe struct hmm_mirror *mirror, 904a3e0d41cSJérôme Glisse unsigned long start, 90563d5066fSJérôme Glisse unsigned long end, 90663d5066fSJérôme Glisse unsigned page_shift) 907a3e0d41cSJérôme Glisse { 90863d5066fSJérôme Glisse unsigned long mask = ((1UL << page_shift) - 1UL); 909e36acfe6SJason Gunthorpe struct hmm *hmm = mirror->hmm; 91063d5066fSJérôme Glisse 911a3e0d41cSJérôme Glisse range->valid = false; 912a3e0d41cSJérôme Glisse range->hmm = NULL; 913a3e0d41cSJérôme Glisse 91463d5066fSJérôme Glisse if ((start & mask) || (end & mask)) 91563d5066fSJérôme Glisse return -EINVAL; 91663d5066fSJérôme Glisse if (start >= end) 917a3e0d41cSJérôme Glisse return -EINVAL; 918a3e0d41cSJérôme Glisse 91963d5066fSJérôme Glisse range->page_shift = page_shift; 920a3e0d41cSJérôme Glisse range->start = start; 921a3e0d41cSJérôme Glisse range->end = end; 922a3e0d41cSJérôme Glisse 923a3e0d41cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 924e36acfe6SJason Gunthorpe if (hmm->mm == NULL || hmm->dead) 925a3e0d41cSJérôme Glisse return -EFAULT; 926a3e0d41cSJérôme Glisse 927085ea250SRalph Campbell /* Initialize range to track CPU page table updates. */ 928085ea250SRalph Campbell mutex_lock(&hmm->lock); 929a3e0d41cSJérôme Glisse 930085ea250SRalph Campbell range->hmm = hmm; 931e36acfe6SJason Gunthorpe kref_get(&hmm->kref); 932085ea250SRalph Campbell list_add_rcu(&range->list, &hmm->ranges); 933a3e0d41cSJérôme Glisse 934a3e0d41cSJérôme Glisse /* 935a3e0d41cSJérôme Glisse * If there are any concurrent notifiers we have to wait for them for 936a3e0d41cSJérôme Glisse * the range to be valid (see hmm_range_wait_until_valid()). 937a3e0d41cSJérôme Glisse */ 938085ea250SRalph Campbell if (!hmm->notifiers) 939a3e0d41cSJérôme Glisse range->valid = true; 940085ea250SRalph Campbell mutex_unlock(&hmm->lock); 941a3e0d41cSJérôme Glisse 942a3e0d41cSJérôme Glisse return 0; 943a3e0d41cSJérôme Glisse } 944a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_register); 945a3e0d41cSJérôme Glisse 946a3e0d41cSJérôme Glisse /* 947a3e0d41cSJérôme Glisse * hmm_range_unregister() - stop tracking change to CPU page table over a range 948a3e0d41cSJérôme Glisse * @range: range 949a3e0d41cSJérôme Glisse * 950a3e0d41cSJérôme Glisse * Range struct is used to track updates to the CPU page table after a call to 951a3e0d41cSJérôme Glisse * hmm_range_register(). See include/linux/hmm.h for how to use it. 952a3e0d41cSJérôme Glisse */ 953a3e0d41cSJérôme Glisse void hmm_range_unregister(struct hmm_range *range) 954a3e0d41cSJérôme Glisse { 955085ea250SRalph Campbell struct hmm *hmm = range->hmm; 956085ea250SRalph Campbell 957a3e0d41cSJérôme Glisse /* Sanity check this really should not happen. */ 958085ea250SRalph Campbell if (hmm == NULL || range->end <= range->start) 959a3e0d41cSJérôme Glisse return; 960a3e0d41cSJérôme Glisse 961085ea250SRalph Campbell mutex_lock(&hmm->lock); 962a3e0d41cSJérôme Glisse list_del_rcu(&range->list); 963085ea250SRalph Campbell mutex_unlock(&hmm->lock); 964a3e0d41cSJérôme Glisse 965a3e0d41cSJérôme Glisse /* Drop reference taken by hmm_range_register() */ 966a3e0d41cSJérôme Glisse range->valid = false; 967085ea250SRalph Campbell hmm_put(hmm); 968a3e0d41cSJérôme Glisse range->hmm = NULL; 969a3e0d41cSJérôme Glisse } 970a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_unregister); 971a3e0d41cSJérôme Glisse 972a3e0d41cSJérôme Glisse /* 97325f23a0cSJérôme Glisse * hmm_range_snapshot() - snapshot CPU page table for a range 97425f23a0cSJérôme Glisse * @range: range 975085ea250SRalph Campbell * Return: -EINVAL if invalid argument, -ENOMEM out of memory, -EPERM invalid 976a3e0d41cSJérôme Glisse * permission (for instance asking for write and range is read only), 977a3e0d41cSJérôme Glisse * -EAGAIN if you need to retry, -EFAULT invalid (ie either no valid 978a3e0d41cSJérôme Glisse * vma or it is illegal to access that range), number of valid pages 979a3e0d41cSJérôme Glisse * in range->pfns[] (from range start address). 980da4c3c73SJérôme Glisse * 981da4c3c73SJérôme Glisse * This snapshots the CPU page table for a range of virtual addresses. Snapshot 982a3e0d41cSJérôme Glisse * validity is tracked by range struct. See in include/linux/hmm.h for example 983a3e0d41cSJérôme Glisse * on how to use. 984da4c3c73SJérôme Glisse */ 98525f23a0cSJérôme Glisse long hmm_range_snapshot(struct hmm_range *range) 986da4c3c73SJérôme Glisse { 98763d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 988a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 98974eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 990a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 991a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 992da4c3c73SJérôme Glisse struct mm_walk mm_walk; 993704f3f2cSJérôme Glisse 994704f3f2cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 995a3e0d41cSJérôme Glisse if (hmm->mm == NULL || hmm->dead) 996a3e0d41cSJérôme Glisse return -EFAULT; 997da4c3c73SJérôme Glisse 998a3e0d41cSJérôme Glisse do { 999a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 1000a3e0d41cSJérôme Glisse if (!range->valid) 1001a3e0d41cSJérôme Glisse return -EAGAIN; 1002a3e0d41cSJérôme Glisse 1003a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 100463d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 1005a3e0d41cSJérôme Glisse return -EFAULT; 1006a3e0d41cSJérôme Glisse 100763d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 10081c2308f0SJason Gunthorpe if (huge_page_shift(hstate_vma(vma)) != 10091c2308f0SJason Gunthorpe range->page_shift && 101063d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 101163d5066fSJérôme Glisse return -EINVAL; 101263d5066fSJérôme Glisse } else { 101363d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 101463d5066fSJérôme Glisse return -EINVAL; 101563d5066fSJérôme Glisse } 101663d5066fSJérôme Glisse 101786586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 101886586a41SJérôme Glisse /* 1019a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 1020a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 1021a3e0d41cSJérôme Glisse * support architecture that allow write without read. 102286586a41SJérôme Glisse */ 1023a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 1024a3e0d41cSJérôme Glisse range->start, range->end); 102586586a41SJérôme Glisse return -EPERM; 102686586a41SJérôme Glisse } 102786586a41SJérôme Glisse 1028a3e0d41cSJérôme Glisse range->vma = vma; 1029992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1030a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 103174eee180SJérôme Glisse hmm_vma_walk.fault = false; 103274eee180SJérôme Glisse hmm_vma_walk.range = range; 103374eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1034a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 103574eee180SJérôme Glisse 1036da4c3c73SJérôme Glisse mm_walk.vma = vma; 1037da4c3c73SJérôme Glisse mm_walk.mm = vma->vm_mm; 1038da4c3c73SJérôme Glisse mm_walk.pte_entry = NULL; 1039da4c3c73SJérôme Glisse mm_walk.test_walk = NULL; 1040da4c3c73SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1041992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 1042da4c3c73SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 1043da4c3c73SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 104463d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 1045da4c3c73SJérôme Glisse 1046a3e0d41cSJérôme Glisse walk_page_range(start, end, &mm_walk); 1047a3e0d41cSJérôme Glisse start = end; 1048a3e0d41cSJérôme Glisse } while (start < range->end); 1049a3e0d41cSJérôme Glisse 105025f23a0cSJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1051da4c3c73SJérôme Glisse } 105225f23a0cSJérôme Glisse EXPORT_SYMBOL(hmm_range_snapshot); 1053da4c3c73SJérôme Glisse 1054da4c3c73SJérôme Glisse /* 105573231612SJérôme Glisse * hmm_range_fault() - try to fault some address in a virtual address range 105608232a45SJérôme Glisse * @range: range being faulted 105774eee180SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1058085ea250SRalph Campbell * Return: number of valid pages in range->pfns[] (from range start 105973231612SJérôme Glisse * address). This may be zero. If the return value is negative, 106073231612SJérôme Glisse * then one of the following values may be returned: 106173231612SJérôme Glisse * 106273231612SJérôme Glisse * -EINVAL invalid arguments or mm or virtual address are in an 106363d5066fSJérôme Glisse * invalid vma (for instance device file vma). 106473231612SJérôme Glisse * -ENOMEM: Out of memory. 106573231612SJérôme Glisse * -EPERM: Invalid permission (for instance asking for write and 106673231612SJérôme Glisse * range is read only). 106773231612SJérôme Glisse * -EAGAIN: If you need to retry and mmap_sem was drop. This can only 106873231612SJérôme Glisse * happens if block argument is false. 106973231612SJérôme Glisse * -EBUSY: If the the range is being invalidated and you should wait 107073231612SJérôme Glisse * for invalidation to finish. 107173231612SJérôme Glisse * -EFAULT: Invalid (ie either no valid vma or it is illegal to access 107273231612SJérôme Glisse * that range), number of valid pages in range->pfns[] (from 107373231612SJérôme Glisse * range start address). 107474eee180SJérôme Glisse * 107574eee180SJérôme Glisse * This is similar to a regular CPU page fault except that it will not trigger 107673231612SJérôme Glisse * any memory migration if the memory being faulted is not accessible by CPUs 107773231612SJérôme Glisse * and caller does not ask for migration. 107874eee180SJérôme Glisse * 1079ff05c0c6SJérôme Glisse * On error, for one virtual address in the range, the function will mark the 1080ff05c0c6SJérôme Glisse * corresponding HMM pfn entry with an error flag. 108174eee180SJérôme Glisse */ 108273231612SJérôme Glisse long hmm_range_fault(struct hmm_range *range, bool block) 108374eee180SJérôme Glisse { 108463d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 1085a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 108674eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 1087a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 1088a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 108974eee180SJérôme Glisse struct mm_walk mm_walk; 109074eee180SJérôme Glisse int ret; 109174eee180SJérôme Glisse 1092704f3f2cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 1093a3e0d41cSJérôme Glisse if (hmm->mm == NULL || hmm->dead) 1094a3e0d41cSJérôme Glisse return -EFAULT; 1095a3e0d41cSJérôme Glisse 1096a3e0d41cSJérôme Glisse do { 1097a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 1098a3e0d41cSJérôme Glisse if (!range->valid) { 1099a3e0d41cSJérôme Glisse up_read(&hmm->mm->mmap_sem); 1100a3e0d41cSJérôme Glisse return -EAGAIN; 1101704f3f2cSJérôme Glisse } 110274eee180SJérôme Glisse 1103a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 110463d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 1105a3e0d41cSJérôme Glisse return -EFAULT; 1106a3e0d41cSJérôme Glisse 110763d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 110863d5066fSJérôme Glisse if (huge_page_shift(hstate_vma(vma)) != 110963d5066fSJérôme Glisse range->page_shift && 111063d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 111163d5066fSJérôme Glisse return -EINVAL; 111263d5066fSJérôme Glisse } else { 111363d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 111463d5066fSJérôme Glisse return -EINVAL; 111563d5066fSJérôme Glisse } 111663d5066fSJérôme Glisse 111786586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 111886586a41SJérôme Glisse /* 1119a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 1120a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 1121a3e0d41cSJérôme Glisse * support architecture that allow write without read. 112286586a41SJérôme Glisse */ 1123a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 1124a3e0d41cSJérôme Glisse range->start, range->end); 112586586a41SJérôme Glisse return -EPERM; 112686586a41SJérôme Glisse } 112774eee180SJérôme Glisse 1128a3e0d41cSJérôme Glisse range->vma = vma; 1129992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1130a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 113174eee180SJérôme Glisse hmm_vma_walk.fault = true; 113274eee180SJérôme Glisse hmm_vma_walk.block = block; 113374eee180SJérôme Glisse hmm_vma_walk.range = range; 113474eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1135a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 113674eee180SJérôme Glisse 113774eee180SJérôme Glisse mm_walk.vma = vma; 113874eee180SJérôme Glisse mm_walk.mm = vma->vm_mm; 113974eee180SJérôme Glisse mm_walk.pte_entry = NULL; 114074eee180SJérôme Glisse mm_walk.test_walk = NULL; 114174eee180SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1142992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 114374eee180SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 114474eee180SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 114563d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 114674eee180SJérôme Glisse 114774eee180SJérôme Glisse do { 1148a3e0d41cSJérôme Glisse ret = walk_page_range(start, end, &mm_walk); 114974eee180SJérôme Glisse start = hmm_vma_walk.last; 1150a3e0d41cSJérôme Glisse 115173231612SJérôme Glisse /* Keep trying while the range is valid. */ 115273231612SJérôme Glisse } while (ret == -EBUSY && range->valid); 115374eee180SJérôme Glisse 115474eee180SJérôme Glisse if (ret) { 115574eee180SJérôme Glisse unsigned long i; 115674eee180SJérôme Glisse 115774eee180SJérôme Glisse i = (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1158a3e0d41cSJérôme Glisse hmm_pfns_clear(range, &range->pfns[i], 1159a3e0d41cSJérôme Glisse hmm_vma_walk.last, range->end); 116073231612SJérôme Glisse return ret; 116174eee180SJérôme Glisse } 1162a3e0d41cSJérôme Glisse start = end; 1163a3e0d41cSJérôme Glisse 1164a3e0d41cSJérôme Glisse } while (start < range->end); 1165704f3f2cSJérôme Glisse 116673231612SJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 116774eee180SJérôme Glisse } 116873231612SJérôme Glisse EXPORT_SYMBOL(hmm_range_fault); 116955c0ece8SJérôme Glisse 117055c0ece8SJérôme Glisse /** 117155c0ece8SJérôme Glisse * hmm_range_dma_map() - hmm_range_fault() and dma map page all in one. 117255c0ece8SJérôme Glisse * @range: range being faulted 117355c0ece8SJérôme Glisse * @device: device against to dma map page to 117455c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 117555c0ece8SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1176085ea250SRalph Campbell * Return: number of pages mapped on success, -EAGAIN if mmap_sem have been 117755c0ece8SJérôme Glisse * drop and you need to try again, some other error value otherwise 117855c0ece8SJérôme Glisse * 117955c0ece8SJérôme Glisse * Note same usage pattern as hmm_range_fault(). 118055c0ece8SJérôme Glisse */ 118155c0ece8SJérôme Glisse long hmm_range_dma_map(struct hmm_range *range, 118255c0ece8SJérôme Glisse struct device *device, 118355c0ece8SJérôme Glisse dma_addr_t *daddrs, 118455c0ece8SJérôme Glisse bool block) 118555c0ece8SJérôme Glisse { 118655c0ece8SJérôme Glisse unsigned long i, npages, mapped; 118755c0ece8SJérôme Glisse long ret; 118855c0ece8SJérôme Glisse 118955c0ece8SJérôme Glisse ret = hmm_range_fault(range, block); 119055c0ece8SJérôme Glisse if (ret <= 0) 119155c0ece8SJérôme Glisse return ret ? ret : -EBUSY; 119255c0ece8SJérôme Glisse 119355c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 119455c0ece8SJérôme Glisse for (i = 0, mapped = 0; i < npages; ++i) { 119555c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 119655c0ece8SJérôme Glisse struct page *page; 119755c0ece8SJérôme Glisse 119855c0ece8SJérôme Glisse /* 119955c0ece8SJérôme Glisse * FIXME need to update DMA API to provide invalid DMA address 120055c0ece8SJérôme Glisse * value instead of a function to test dma address value. This 120155c0ece8SJérôme Glisse * would remove lot of dumb code duplicated accross many arch. 120255c0ece8SJérôme Glisse * 120355c0ece8SJérôme Glisse * For now setting it to 0 here is good enough as the pfns[] 120455c0ece8SJérôme Glisse * value is what is use to check what is valid and what isn't. 120555c0ece8SJérôme Glisse */ 120655c0ece8SJérôme Glisse daddrs[i] = 0; 120755c0ece8SJérôme Glisse 1208391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 120955c0ece8SJérôme Glisse if (page == NULL) 121055c0ece8SJérôme Glisse continue; 121155c0ece8SJérôme Glisse 121255c0ece8SJérôme Glisse /* Check if range is being invalidated */ 121355c0ece8SJérôme Glisse if (!range->valid) { 121455c0ece8SJérôme Glisse ret = -EBUSY; 121555c0ece8SJérôme Glisse goto unmap; 121655c0ece8SJérôme Glisse } 121755c0ece8SJérôme Glisse 121855c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 121955c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) 122055c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 122155c0ece8SJérôme Glisse 122255c0ece8SJérôme Glisse daddrs[i] = dma_map_page(device, page, 0, PAGE_SIZE, dir); 122355c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) { 122455c0ece8SJérôme Glisse ret = -EFAULT; 122555c0ece8SJérôme Glisse goto unmap; 122655c0ece8SJérôme Glisse } 122755c0ece8SJérôme Glisse 122855c0ece8SJérôme Glisse mapped++; 122955c0ece8SJérôme Glisse } 123055c0ece8SJérôme Glisse 123155c0ece8SJérôme Glisse return mapped; 123255c0ece8SJérôme Glisse 123355c0ece8SJérôme Glisse unmap: 123455c0ece8SJérôme Glisse for (npages = i, i = 0; (i < npages) && mapped; ++i) { 123555c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 123655c0ece8SJérôme Glisse struct page *page; 123755c0ece8SJérôme Glisse 1238391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 123955c0ece8SJérôme Glisse if (page == NULL) 124055c0ece8SJérôme Glisse continue; 124155c0ece8SJérôme Glisse 124255c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) 124355c0ece8SJérôme Glisse continue; 124455c0ece8SJérôme Glisse 124555c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 124655c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) 124755c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 124855c0ece8SJérôme Glisse 124955c0ece8SJérôme Glisse dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 125055c0ece8SJérôme Glisse mapped--; 125155c0ece8SJérôme Glisse } 125255c0ece8SJérôme Glisse 125355c0ece8SJérôme Glisse return ret; 125455c0ece8SJérôme Glisse } 125555c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_map); 125655c0ece8SJérôme Glisse 125755c0ece8SJérôme Glisse /** 125855c0ece8SJérôme Glisse * hmm_range_dma_unmap() - unmap range of that was map with hmm_range_dma_map() 125955c0ece8SJérôme Glisse * @range: range being unmapped 126055c0ece8SJérôme Glisse * @vma: the vma against which the range (optional) 126155c0ece8SJérôme Glisse * @device: device against which dma map was done 126255c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 126355c0ece8SJérôme Glisse * @dirty: dirty page if it had the write flag set 1264085ea250SRalph Campbell * Return: number of page unmapped on success, -EINVAL otherwise 126555c0ece8SJérôme Glisse * 126655c0ece8SJérôme Glisse * Note that caller MUST abide by mmu notifier or use HMM mirror and abide 126755c0ece8SJérôme Glisse * to the sync_cpu_device_pagetables() callback so that it is safe here to 126855c0ece8SJérôme Glisse * call set_page_dirty(). Caller must also take appropriate locks to avoid 126955c0ece8SJérôme Glisse * concurrent mmu notifier or sync_cpu_device_pagetables() to make progress. 127055c0ece8SJérôme Glisse */ 127155c0ece8SJérôme Glisse long hmm_range_dma_unmap(struct hmm_range *range, 127255c0ece8SJérôme Glisse struct vm_area_struct *vma, 127355c0ece8SJérôme Glisse struct device *device, 127455c0ece8SJérôme Glisse dma_addr_t *daddrs, 127555c0ece8SJérôme Glisse bool dirty) 127655c0ece8SJérôme Glisse { 127755c0ece8SJérôme Glisse unsigned long i, npages; 127855c0ece8SJérôme Glisse long cpages = 0; 127955c0ece8SJérôme Glisse 128055c0ece8SJérôme Glisse /* Sanity check. */ 128155c0ece8SJérôme Glisse if (range->end <= range->start) 128255c0ece8SJérôme Glisse return -EINVAL; 128355c0ece8SJérôme Glisse if (!daddrs) 128455c0ece8SJérôme Glisse return -EINVAL; 128555c0ece8SJérôme Glisse if (!range->pfns) 128655c0ece8SJérôme Glisse return -EINVAL; 128755c0ece8SJérôme Glisse 128855c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 128955c0ece8SJérôme Glisse for (i = 0; i < npages; ++i) { 129055c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 129155c0ece8SJérôme Glisse struct page *page; 129255c0ece8SJérôme Glisse 1293391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 129455c0ece8SJérôme Glisse if (page == NULL) 129555c0ece8SJérôme Glisse continue; 129655c0ece8SJérôme Glisse 129755c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 129855c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) { 129955c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 130055c0ece8SJérôme Glisse 130155c0ece8SJérôme Glisse /* 130255c0ece8SJérôme Glisse * See comments in function description on why it is 130355c0ece8SJérôme Glisse * safe here to call set_page_dirty() 130455c0ece8SJérôme Glisse */ 130555c0ece8SJérôme Glisse if (dirty) 130655c0ece8SJérôme Glisse set_page_dirty(page); 130755c0ece8SJérôme Glisse } 130855c0ece8SJérôme Glisse 130955c0ece8SJérôme Glisse /* Unmap and clear pfns/dma address */ 131055c0ece8SJérôme Glisse dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 131155c0ece8SJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 131255c0ece8SJérôme Glisse /* FIXME see comments in hmm_vma_dma_map() */ 131355c0ece8SJérôme Glisse daddrs[i] = 0; 131455c0ece8SJérôme Glisse cpages++; 131555c0ece8SJérôme Glisse } 131655c0ece8SJérôme Glisse 131755c0ece8SJérôme Glisse return cpages; 131855c0ece8SJérôme Glisse } 131955c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_unmap); 1320c0b12405SJérôme Glisse #endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */ 13214ef589dcSJérôme Glisse 13224ef589dcSJérôme Glisse 1323df6ad698SJérôme Glisse #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) 13244ef589dcSJérôme Glisse struct page *hmm_vma_alloc_locked_page(struct vm_area_struct *vma, 13254ef589dcSJérôme Glisse unsigned long addr) 13264ef589dcSJérôme Glisse { 13274ef589dcSJérôme Glisse struct page *page; 13284ef589dcSJérôme Glisse 13294ef589dcSJérôme Glisse page = alloc_page_vma(GFP_HIGHUSER, vma, addr); 13304ef589dcSJérôme Glisse if (!page) 13314ef589dcSJérôme Glisse return NULL; 13324ef589dcSJérôme Glisse lock_page(page); 13334ef589dcSJérôme Glisse return page; 13344ef589dcSJérôme Glisse } 13354ef589dcSJérôme Glisse EXPORT_SYMBOL(hmm_vma_alloc_locked_page); 13364ef589dcSJérôme Glisse 13374ef589dcSJérôme Glisse 13384ef589dcSJérôme Glisse static void hmm_devmem_ref_release(struct percpu_ref *ref) 13394ef589dcSJérôme Glisse { 13404ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13414ef589dcSJérôme Glisse 13424ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 13434ef589dcSJérôme Glisse complete(&devmem->completion); 13444ef589dcSJérôme Glisse } 13454ef589dcSJérôme Glisse 13464ef589dcSJérôme Glisse static void hmm_devmem_ref_exit(void *data) 13474ef589dcSJérôme Glisse { 13484ef589dcSJérôme Glisse struct percpu_ref *ref = data; 13494ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13504ef589dcSJérôme Glisse 13514ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 1352bbecd94eSDan Williams wait_for_completion(&devmem->completion); 13534ef589dcSJérôme Glisse percpu_ref_exit(ref); 13544ef589dcSJérôme Glisse } 13554ef589dcSJérôme Glisse 1356bbecd94eSDan Williams static void hmm_devmem_ref_kill(struct percpu_ref *ref) 13574ef589dcSJérôme Glisse { 13584ef589dcSJérôme Glisse percpu_ref_kill(ref); 13594ef589dcSJérôme Glisse } 13604ef589dcSJérôme Glisse 1361b57e622eSSouptick Joarder static vm_fault_t hmm_devmem_fault(struct vm_area_struct *vma, 13624ef589dcSJérôme Glisse unsigned long addr, 13634ef589dcSJérôme Glisse const struct page *page, 13644ef589dcSJérôme Glisse unsigned int flags, 13654ef589dcSJérôme Glisse pmd_t *pmdp) 13664ef589dcSJérôme Glisse { 13674ef589dcSJérôme Glisse struct hmm_devmem *devmem = page->pgmap->data; 13684ef589dcSJérôme Glisse 13694ef589dcSJérôme Glisse return devmem->ops->fault(devmem, vma, addr, page, flags, pmdp); 13704ef589dcSJérôme Glisse } 13714ef589dcSJérôme Glisse 13724ef589dcSJérôme Glisse static void hmm_devmem_free(struct page *page, void *data) 13734ef589dcSJérôme Glisse { 13744ef589dcSJérôme Glisse struct hmm_devmem *devmem = data; 13754ef589dcSJérôme Glisse 13762fa147bdSDan Williams page->mapping = NULL; 13772fa147bdSDan Williams 13784ef589dcSJérôme Glisse devmem->ops->free(devmem, page); 13794ef589dcSJérôme Glisse } 13804ef589dcSJérôme Glisse 13814ef589dcSJérôme Glisse /* 13824ef589dcSJérôme Glisse * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory 13834ef589dcSJérôme Glisse * 13844ef589dcSJérôme Glisse * @ops: memory event device driver callback (see struct hmm_devmem_ops) 13854ef589dcSJérôme Glisse * @device: device struct to bind the resource too 13864ef589dcSJérôme Glisse * @size: size in bytes of the device memory to add 1387085ea250SRalph Campbell * Return: pointer to new hmm_devmem struct ERR_PTR otherwise 13884ef589dcSJérôme Glisse * 13894ef589dcSJérôme Glisse * This function first finds an empty range of physical address big enough to 13904ef589dcSJérôme Glisse * contain the new resource, and then hotplugs it as ZONE_DEVICE memory, which 13914ef589dcSJérôme Glisse * in turn allocates struct pages. It does not do anything beyond that; all 13924ef589dcSJérôme Glisse * events affecting the memory will go through the various callbacks provided 13934ef589dcSJérôme Glisse * by hmm_devmem_ops struct. 13944ef589dcSJérôme Glisse * 13954ef589dcSJérôme Glisse * Device driver should call this function during device initialization and 13964ef589dcSJérôme Glisse * is then responsible of memory management. HMM only provides helpers. 13974ef589dcSJérôme Glisse */ 13984ef589dcSJérôme Glisse struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 13994ef589dcSJérôme Glisse struct device *device, 14004ef589dcSJérôme Glisse unsigned long size) 14014ef589dcSJérôme Glisse { 14024ef589dcSJérôme Glisse struct hmm_devmem *devmem; 14034ef589dcSJérôme Glisse resource_size_t addr; 1404bbecd94eSDan Williams void *result; 14054ef589dcSJérôme Glisse int ret; 14064ef589dcSJérôme Glisse 1407e7638488SDan Williams dev_pagemap_get_ops(); 14084ef589dcSJérôme Glisse 140958ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 14104ef589dcSJérôme Glisse if (!devmem) 14114ef589dcSJérôme Glisse return ERR_PTR(-ENOMEM); 14124ef589dcSJérôme Glisse 14134ef589dcSJérôme Glisse init_completion(&devmem->completion); 14144ef589dcSJérôme Glisse devmem->pfn_first = -1UL; 14154ef589dcSJérôme Glisse devmem->pfn_last = -1UL; 14164ef589dcSJérôme Glisse devmem->resource = NULL; 14174ef589dcSJérôme Glisse devmem->device = device; 14184ef589dcSJérôme Glisse devmem->ops = ops; 14194ef589dcSJérôme Glisse 14204ef589dcSJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 14214ef589dcSJérôme Glisse 0, GFP_KERNEL); 14224ef589dcSJérôme Glisse if (ret) 142358ef15b7SDan Williams return ERR_PTR(ret); 14244ef589dcSJérôme Glisse 142558ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, &devmem->ref); 14264ef589dcSJérôme Glisse if (ret) 142758ef15b7SDan Williams return ERR_PTR(ret); 14284ef589dcSJérôme Glisse 14294ef589dcSJérôme Glisse size = ALIGN(size, PA_SECTION_SIZE); 14304ef589dcSJérôme Glisse addr = min((unsigned long)iomem_resource.end, 14314ef589dcSJérôme Glisse (1UL << MAX_PHYSMEM_BITS) - 1); 14324ef589dcSJérôme Glisse addr = addr - size + 1UL; 14334ef589dcSJérôme Glisse 14344ef589dcSJérôme Glisse /* 14354ef589dcSJérôme Glisse * FIXME add a new helper to quickly walk resource tree and find free 14364ef589dcSJérôme Glisse * range 14374ef589dcSJérôme Glisse * 14384ef589dcSJérôme Glisse * FIXME what about ioport_resource resource ? 14394ef589dcSJérôme Glisse */ 14404ef589dcSJérôme Glisse for (; addr > size && addr >= iomem_resource.start; addr -= size) { 14414ef589dcSJérôme Glisse ret = region_intersects(addr, size, 0, IORES_DESC_NONE); 14424ef589dcSJérôme Glisse if (ret != REGION_DISJOINT) 14434ef589dcSJérôme Glisse continue; 14444ef589dcSJérôme Glisse 14454ef589dcSJérôme Glisse devmem->resource = devm_request_mem_region(device, addr, size, 14464ef589dcSJérôme Glisse dev_name(device)); 144758ef15b7SDan Williams if (!devmem->resource) 144858ef15b7SDan Williams return ERR_PTR(-ENOMEM); 14494ef589dcSJérôme Glisse break; 14504ef589dcSJérôme Glisse } 145158ef15b7SDan Williams if (!devmem->resource) 145258ef15b7SDan Williams return ERR_PTR(-ERANGE); 14534ef589dcSJérôme Glisse 14544ef589dcSJérôme Glisse devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; 14554ef589dcSJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 14564ef589dcSJérôme Glisse devmem->pfn_last = devmem->pfn_first + 14574ef589dcSJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1458063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 14594ef589dcSJérôme Glisse 1460bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; 1461bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1462bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1463bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1464bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1465bbecd94eSDan Williams devmem->pagemap.data = devmem; 1466bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 146758ef15b7SDan Williams 1468bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1469bbecd94eSDan Williams if (IS_ERR(result)) 1470bbecd94eSDan Williams return result; 14714ef589dcSJérôme Glisse return devmem; 14724ef589dcSJérôme Glisse } 147302917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add); 14744ef589dcSJérôme Glisse 1475d3df0a42SJérôme Glisse struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, 1476d3df0a42SJérôme Glisse struct device *device, 1477d3df0a42SJérôme Glisse struct resource *res) 1478d3df0a42SJérôme Glisse { 1479d3df0a42SJérôme Glisse struct hmm_devmem *devmem; 1480bbecd94eSDan Williams void *result; 1481d3df0a42SJérôme Glisse int ret; 1482d3df0a42SJérôme Glisse 1483d3df0a42SJérôme Glisse if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) 1484d3df0a42SJérôme Glisse return ERR_PTR(-EINVAL); 1485d3df0a42SJérôme Glisse 1486e7638488SDan Williams dev_pagemap_get_ops(); 1487d3df0a42SJérôme Glisse 148858ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 1489d3df0a42SJérôme Glisse if (!devmem) 1490d3df0a42SJérôme Glisse return ERR_PTR(-ENOMEM); 1491d3df0a42SJérôme Glisse 1492d3df0a42SJérôme Glisse init_completion(&devmem->completion); 1493d3df0a42SJérôme Glisse devmem->pfn_first = -1UL; 1494d3df0a42SJérôme Glisse devmem->pfn_last = -1UL; 1495d3df0a42SJérôme Glisse devmem->resource = res; 1496d3df0a42SJérôme Glisse devmem->device = device; 1497d3df0a42SJérôme Glisse devmem->ops = ops; 1498d3df0a42SJérôme Glisse 1499d3df0a42SJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 1500d3df0a42SJérôme Glisse 0, GFP_KERNEL); 1501d3df0a42SJérôme Glisse if (ret) 150258ef15b7SDan Williams return ERR_PTR(ret); 1503d3df0a42SJérôme Glisse 150458ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, 150558ef15b7SDan Williams &devmem->ref); 1506d3df0a42SJérôme Glisse if (ret) 150758ef15b7SDan Williams return ERR_PTR(ret); 1508d3df0a42SJérôme Glisse 1509d3df0a42SJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 1510d3df0a42SJérôme Glisse devmem->pfn_last = devmem->pfn_first + 1511d3df0a42SJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1512063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 1513d3df0a42SJérôme Glisse 1514bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PUBLIC; 1515bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1516bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1517bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1518bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1519bbecd94eSDan Williams devmem->pagemap.data = devmem; 1520bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 152158ef15b7SDan Williams 1522bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1523bbecd94eSDan Williams if (IS_ERR(result)) 1524bbecd94eSDan Williams return result; 1525d3df0a42SJérôme Glisse return devmem; 1526d3df0a42SJérôme Glisse } 152702917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add_resource); 1528d3df0a42SJérôme Glisse 15294ef589dcSJérôme Glisse /* 1530858b54daSJérôme Glisse * A device driver that wants to handle multiple devices memory through a 1531858b54daSJérôme Glisse * single fake device can use hmm_device to do so. This is purely a helper 1532858b54daSJérôme Glisse * and it is not needed to make use of any HMM functionality. 1533858b54daSJérôme Glisse */ 1534858b54daSJérôme Glisse #define HMM_DEVICE_MAX 256 1535858b54daSJérôme Glisse 1536858b54daSJérôme Glisse static DECLARE_BITMAP(hmm_device_mask, HMM_DEVICE_MAX); 1537858b54daSJérôme Glisse static DEFINE_SPINLOCK(hmm_device_lock); 1538858b54daSJérôme Glisse static struct class *hmm_device_class; 1539858b54daSJérôme Glisse static dev_t hmm_device_devt; 1540858b54daSJérôme Glisse 1541858b54daSJérôme Glisse static void hmm_device_release(struct device *device) 1542858b54daSJérôme Glisse { 1543858b54daSJérôme Glisse struct hmm_device *hmm_device; 1544858b54daSJérôme Glisse 1545858b54daSJérôme Glisse hmm_device = container_of(device, struct hmm_device, device); 1546858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1547858b54daSJérôme Glisse clear_bit(hmm_device->minor, hmm_device_mask); 1548858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1549858b54daSJérôme Glisse 1550858b54daSJérôme Glisse kfree(hmm_device); 1551858b54daSJérôme Glisse } 1552858b54daSJérôme Glisse 1553858b54daSJérôme Glisse struct hmm_device *hmm_device_new(void *drvdata) 1554858b54daSJérôme Glisse { 1555858b54daSJérôme Glisse struct hmm_device *hmm_device; 1556858b54daSJérôme Glisse 1557858b54daSJérôme Glisse hmm_device = kzalloc(sizeof(*hmm_device), GFP_KERNEL); 1558858b54daSJérôme Glisse if (!hmm_device) 1559858b54daSJérôme Glisse return ERR_PTR(-ENOMEM); 1560858b54daSJérôme Glisse 1561858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1562858b54daSJérôme Glisse hmm_device->minor = find_first_zero_bit(hmm_device_mask, HMM_DEVICE_MAX); 1563858b54daSJérôme Glisse if (hmm_device->minor >= HMM_DEVICE_MAX) { 1564858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1565858b54daSJérôme Glisse kfree(hmm_device); 1566858b54daSJérôme Glisse return ERR_PTR(-EBUSY); 1567858b54daSJérôme Glisse } 1568858b54daSJérôme Glisse set_bit(hmm_device->minor, hmm_device_mask); 1569858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1570858b54daSJérôme Glisse 1571858b54daSJérôme Glisse dev_set_name(&hmm_device->device, "hmm_device%d", hmm_device->minor); 1572858b54daSJérôme Glisse hmm_device->device.devt = MKDEV(MAJOR(hmm_device_devt), 1573858b54daSJérôme Glisse hmm_device->minor); 1574858b54daSJérôme Glisse hmm_device->device.release = hmm_device_release; 1575858b54daSJérôme Glisse dev_set_drvdata(&hmm_device->device, drvdata); 1576858b54daSJérôme Glisse hmm_device->device.class = hmm_device_class; 1577858b54daSJérôme Glisse device_initialize(&hmm_device->device); 1578858b54daSJérôme Glisse 1579858b54daSJérôme Glisse return hmm_device; 1580858b54daSJérôme Glisse } 1581858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_new); 1582858b54daSJérôme Glisse 1583858b54daSJérôme Glisse void hmm_device_put(struct hmm_device *hmm_device) 1584858b54daSJérôme Glisse { 1585858b54daSJérôme Glisse put_device(&hmm_device->device); 1586858b54daSJérôme Glisse } 1587858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_put); 1588858b54daSJérôme Glisse 1589858b54daSJérôme Glisse static int __init hmm_init(void) 1590858b54daSJérôme Glisse { 1591858b54daSJérôme Glisse int ret; 1592858b54daSJérôme Glisse 1593858b54daSJérôme Glisse ret = alloc_chrdev_region(&hmm_device_devt, 0, 1594858b54daSJérôme Glisse HMM_DEVICE_MAX, 1595858b54daSJérôme Glisse "hmm_device"); 1596858b54daSJérôme Glisse if (ret) 1597858b54daSJérôme Glisse return ret; 1598858b54daSJérôme Glisse 1599858b54daSJérôme Glisse hmm_device_class = class_create(THIS_MODULE, "hmm_device"); 1600858b54daSJérôme Glisse if (IS_ERR(hmm_device_class)) { 1601858b54daSJérôme Glisse unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX); 1602858b54daSJérôme Glisse return PTR_ERR(hmm_device_class); 1603858b54daSJérôme Glisse } 1604858b54daSJérôme Glisse return 0; 1605858b54daSJérôme Glisse } 1606858b54daSJérôme Glisse 1607858b54daSJérôme Glisse device_initcall(hmm_init); 1608df6ad698SJérôme Glisse #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ 1609