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> 23c8a53b2dSJason 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 /** 35704f3f2cSJérôme Glisse * hmm_get_or_create - register HMM against an mm (HMM internal) 36704f3f2cSJérôme Glisse * 37704f3f2cSJérôme Glisse * @mm: mm struct to attach to 38704f3f2cSJérôme Glisse * Returns: returns an HMM object, either by referencing the existing 39704f3f2cSJérôme Glisse * (per-process) object, or by creating a new one. 40704f3f2cSJérôme Glisse * 41704f3f2cSJérôme Glisse * This is not intended to be used directly by device drivers. If mm already 42704f3f2cSJérôme Glisse * has an HMM struct then it get a reference on it and returns it. Otherwise 43704f3f2cSJérôme Glisse * it allocates an HMM struct, initializes it, associate it with the mm and 44704f3f2cSJérôme Glisse * returns it. 45704f3f2cSJérôme Glisse */ 46704f3f2cSJérôme Glisse static struct hmm *hmm_get_or_create(struct mm_struct *mm) 47704f3f2cSJérôme Glisse { 488a9320b7SJason Gunthorpe struct hmm *hmm; 49133ff0eaSJérôme Glisse 508a9320b7SJason Gunthorpe lockdep_assert_held_exclusive(&mm->mmap_sem); 518a9320b7SJason Gunthorpe 528a9320b7SJason Gunthorpe /* Abuse the page_table_lock to also protect mm->hmm. */ 538a9320b7SJason Gunthorpe spin_lock(&mm->page_table_lock); 548a9320b7SJason Gunthorpe hmm = mm->hmm; 558a9320b7SJason Gunthorpe if (mm->hmm && kref_get_unless_zero(&mm->hmm->kref)) 568a9320b7SJason Gunthorpe goto out_unlock; 578a9320b7SJason Gunthorpe spin_unlock(&mm->page_table_lock); 58c0b12405SJérôme Glisse 59c0b12405SJérôme Glisse hmm = kmalloc(sizeof(*hmm), GFP_KERNEL); 60c0b12405SJérôme Glisse if (!hmm) 61c0b12405SJérôme Glisse return NULL; 62a3e0d41cSJérôme Glisse init_waitqueue_head(&hmm->wq); 63c0b12405SJérôme Glisse INIT_LIST_HEAD(&hmm->mirrors); 64c0b12405SJérôme Glisse init_rwsem(&hmm->mirrors_sem); 65c0b12405SJérôme Glisse hmm->mmu_notifier.ops = NULL; 66da4c3c73SJérôme Glisse INIT_LIST_HEAD(&hmm->ranges); 67a3e0d41cSJérôme Glisse mutex_init(&hmm->lock); 68704f3f2cSJérôme Glisse kref_init(&hmm->kref); 69a3e0d41cSJérôme Glisse hmm->notifiers = 0; 70a3e0d41cSJérôme Glisse hmm->dead = false; 71c0b12405SJérôme Glisse hmm->mm = mm; 72c0b12405SJérôme Glisse 7386a2d598SRalph Campbell hmm->mmu_notifier.ops = &hmm_mmu_notifier_ops; 748a9320b7SJason Gunthorpe if (__mmu_notifier_register(&hmm->mmu_notifier, mm)) { 7586a2d598SRalph Campbell kfree(hmm); 7686a2d598SRalph Campbell return NULL; 77133ff0eaSJérôme Glisse } 78133ff0eaSJérôme Glisse 798a9320b7SJason Gunthorpe mmgrab(hmm->mm); 808a9320b7SJason Gunthorpe 818a9320b7SJason Gunthorpe /* 828a9320b7SJason Gunthorpe * We hold the exclusive mmap_sem here so we know that mm->hmm is 838a9320b7SJason Gunthorpe * still NULL or 0 kref, and is safe to update. 848a9320b7SJason Gunthorpe */ 858a9320b7SJason Gunthorpe spin_lock(&mm->page_table_lock); 868a9320b7SJason Gunthorpe mm->hmm = hmm; 878a9320b7SJason Gunthorpe 888a9320b7SJason Gunthorpe out_unlock: 898a9320b7SJason Gunthorpe spin_unlock(&mm->page_table_lock); 908a9320b7SJason Gunthorpe return hmm; 918a9320b7SJason Gunthorpe } 928a9320b7SJason Gunthorpe 936d7c3cdeSJason Gunthorpe static void hmm_free_rcu(struct rcu_head *rcu) 946d7c3cdeSJason Gunthorpe { 958a9320b7SJason Gunthorpe struct hmm *hmm = container_of(rcu, struct hmm, rcu); 968a9320b7SJason Gunthorpe 978a9320b7SJason Gunthorpe mmdrop(hmm->mm); 988a9320b7SJason Gunthorpe kfree(hmm); 996d7c3cdeSJason Gunthorpe } 1006d7c3cdeSJason Gunthorpe 101704f3f2cSJérôme Glisse static void hmm_free(struct kref *kref) 102704f3f2cSJérôme Glisse { 103704f3f2cSJérôme Glisse struct hmm *hmm = container_of(kref, struct hmm, kref); 104704f3f2cSJérôme Glisse 1058a9320b7SJason Gunthorpe spin_lock(&hmm->mm->page_table_lock); 1068a9320b7SJason Gunthorpe if (hmm->mm->hmm == hmm) 1078a9320b7SJason Gunthorpe hmm->mm->hmm = NULL; 1088a9320b7SJason Gunthorpe spin_unlock(&hmm->mm->page_table_lock); 109704f3f2cSJérôme Glisse 1108a9320b7SJason Gunthorpe mmu_notifier_unregister_no_release(&hmm->mmu_notifier, hmm->mm); 1116d7c3cdeSJason Gunthorpe mmu_notifier_call_srcu(&hmm->rcu, hmm_free_rcu); 112704f3f2cSJérôme Glisse } 113704f3f2cSJérôme Glisse 114704f3f2cSJérôme Glisse static inline void hmm_put(struct hmm *hmm) 115704f3f2cSJérôme Glisse { 116704f3f2cSJérôme Glisse kref_put(&hmm->kref, hmm_free); 117704f3f2cSJérôme Glisse } 118704f3f2cSJérôme Glisse 119a3e0d41cSJérôme Glisse static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) 120c0b12405SJérôme Glisse { 1216d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 122c0b12405SJérôme Glisse struct hmm_mirror *mirror; 123da4c3c73SJérôme Glisse struct hmm_range *range; 124da4c3c73SJérôme Glisse 1256d7c3cdeSJason Gunthorpe /* Bail out if hmm is in the process of being freed */ 1266d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1276d7c3cdeSJason Gunthorpe return; 1286d7c3cdeSJason Gunthorpe 129a3e0d41cSJérôme Glisse /* Report this HMM as dying. */ 130a3e0d41cSJérôme Glisse hmm->dead = true; 131da4c3c73SJérôme Glisse 132a3e0d41cSJérôme Glisse /* Wake-up everyone waiting on any range. */ 133a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 134085ea250SRalph Campbell list_for_each_entry(range, &hmm->ranges, list) 135da4c3c73SJérôme Glisse range->valid = false; 136a3e0d41cSJérôme Glisse wake_up_all(&hmm->wq); 137a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 138e1401513SRalph Campbell 139e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 140e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, struct hmm_mirror, 141e1401513SRalph Campbell list); 142e1401513SRalph Campbell while (mirror) { 143e1401513SRalph Campbell list_del_init(&mirror->list); 144e1401513SRalph Campbell if (mirror->ops->release) { 145e1401513SRalph Campbell /* 146085ea250SRalph Campbell * Drop mirrors_sem so the release callback can wait 147085ea250SRalph Campbell * on any pending work that might itself trigger a 148085ea250SRalph Campbell * mmu_notifier callback and thus would deadlock with 149085ea250SRalph Campbell * us. 150e1401513SRalph Campbell */ 151e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 152e1401513SRalph Campbell mirror->ops->release(mirror); 153e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 154e1401513SRalph Campbell } 155e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, 156e1401513SRalph Campbell struct hmm_mirror, list); 157e1401513SRalph Campbell } 158e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 159704f3f2cSJérôme Glisse 160704f3f2cSJérôme Glisse hmm_put(hmm); 161e1401513SRalph Campbell } 162e1401513SRalph Campbell 16393065ac7SMichal Hocko static int hmm_invalidate_range_start(struct mmu_notifier *mn, 164a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 165c0b12405SJérôme Glisse { 1666d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 167a3e0d41cSJérôme Glisse struct hmm_mirror *mirror; 168ec131b2dSJérôme Glisse struct hmm_update update; 169a3e0d41cSJérôme Glisse struct hmm_range *range; 170a3e0d41cSJérôme Glisse int ret = 0; 171c0b12405SJérôme Glisse 1726d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1736d7c3cdeSJason Gunthorpe return 0; 174c0b12405SJérôme Glisse 175a3e0d41cSJérôme Glisse update.start = nrange->start; 176a3e0d41cSJérôme Glisse update.end = nrange->end; 177ec131b2dSJérôme Glisse update.event = HMM_UPDATE_INVALIDATE; 178dfcd6660SJérôme Glisse update.blockable = mmu_notifier_range_blockable(nrange); 179a3e0d41cSJérôme Glisse 180dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 181a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 182a3e0d41cSJérôme Glisse else if (!mutex_trylock(&hmm->lock)) { 183a3e0d41cSJérôme Glisse ret = -EAGAIN; 184a3e0d41cSJérôme Glisse goto out; 185a3e0d41cSJérôme Glisse } 186a3e0d41cSJérôme Glisse hmm->notifiers++; 187a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 188a3e0d41cSJérôme Glisse if (update.end < range->start || update.start >= range->end) 189a3e0d41cSJérôme Glisse continue; 190a3e0d41cSJérôme Glisse 191a3e0d41cSJérôme Glisse range->valid = false; 192a3e0d41cSJérôme Glisse } 193a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 194a3e0d41cSJérôme Glisse 195dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 196a3e0d41cSJérôme Glisse down_read(&hmm->mirrors_sem); 197a3e0d41cSJérôme Glisse else if (!down_read_trylock(&hmm->mirrors_sem)) { 198a3e0d41cSJérôme Glisse ret = -EAGAIN; 199a3e0d41cSJérôme Glisse goto out; 200a3e0d41cSJérôme Glisse } 201a3e0d41cSJérôme Glisse list_for_each_entry(mirror, &hmm->mirrors, list) { 202a3e0d41cSJérôme Glisse int ret; 203a3e0d41cSJérôme Glisse 204a3e0d41cSJérôme Glisse ret = mirror->ops->sync_cpu_device_pagetables(mirror, &update); 205085ea250SRalph Campbell if (!update.blockable && ret == -EAGAIN) 206085ea250SRalph Campbell break; 207a3e0d41cSJérôme Glisse } 208a3e0d41cSJérôme Glisse up_read(&hmm->mirrors_sem); 209a3e0d41cSJérôme Glisse 210a3e0d41cSJérôme Glisse out: 211704f3f2cSJérôme Glisse hmm_put(hmm); 212704f3f2cSJérôme Glisse return ret; 213c0b12405SJérôme Glisse } 214c0b12405SJérôme Glisse 215c0b12405SJérôme Glisse static void hmm_invalidate_range_end(struct mmu_notifier *mn, 216a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 217c0b12405SJérôme Glisse { 2186d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 219c0b12405SJérôme Glisse 2206d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 2216d7c3cdeSJason Gunthorpe return; 222c0b12405SJérôme Glisse 223a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 224a3e0d41cSJérôme Glisse hmm->notifiers--; 225a3e0d41cSJérôme Glisse if (!hmm->notifiers) { 226a3e0d41cSJérôme Glisse struct hmm_range *range; 227a3e0d41cSJérôme Glisse 228a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 229a3e0d41cSJérôme Glisse if (range->valid) 230a3e0d41cSJérôme Glisse continue; 231a3e0d41cSJérôme Glisse range->valid = true; 232a3e0d41cSJérôme Glisse } 233a3e0d41cSJérôme Glisse wake_up_all(&hmm->wq); 234a3e0d41cSJérôme Glisse } 235a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 236a3e0d41cSJérôme Glisse 237704f3f2cSJérôme Glisse hmm_put(hmm); 238c0b12405SJérôme Glisse } 239c0b12405SJérôme Glisse 240c0b12405SJérôme Glisse static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { 241e1401513SRalph Campbell .release = hmm_release, 242c0b12405SJérôme Glisse .invalidate_range_start = hmm_invalidate_range_start, 243c0b12405SJérôme Glisse .invalidate_range_end = hmm_invalidate_range_end, 244c0b12405SJérôme Glisse }; 245c0b12405SJérôme Glisse 246c0b12405SJérôme Glisse /* 247c0b12405SJérôme Glisse * hmm_mirror_register() - register a mirror against an mm 248c0b12405SJérôme Glisse * 249c0b12405SJérôme Glisse * @mirror: new mirror struct to register 250c0b12405SJérôme Glisse * @mm: mm to register against 251085ea250SRalph Campbell * Return: 0 on success, -ENOMEM if no memory, -EINVAL if invalid arguments 252c0b12405SJérôme Glisse * 253c0b12405SJérôme Glisse * To start mirroring a process address space, the device driver must register 254c0b12405SJérôme Glisse * an HMM mirror struct. 255c0b12405SJérôme Glisse * 256c0b12405SJérôme Glisse * THE mm->mmap_sem MUST BE HELD IN WRITE MODE ! 257c0b12405SJérôme Glisse */ 258c0b12405SJérôme Glisse int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm) 259c0b12405SJérôme Glisse { 260c0b12405SJérôme Glisse /* Sanity check */ 261c0b12405SJérôme Glisse if (!mm || !mirror || !mirror->ops) 262c0b12405SJérôme Glisse return -EINVAL; 263c0b12405SJérôme Glisse 264704f3f2cSJérôme Glisse mirror->hmm = hmm_get_or_create(mm); 265c0b12405SJérôme Glisse if (!mirror->hmm) 266c0b12405SJérôme Glisse return -ENOMEM; 267c0b12405SJérôme Glisse 268c0b12405SJérôme Glisse down_write(&mirror->hmm->mirrors_sem); 269c0b12405SJérôme Glisse list_add(&mirror->list, &mirror->hmm->mirrors); 270c0b12405SJérôme Glisse up_write(&mirror->hmm->mirrors_sem); 271c0b12405SJérôme Glisse 272c0b12405SJérôme Glisse return 0; 273c0b12405SJérôme Glisse } 274c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_register); 275c0b12405SJérôme Glisse 276c0b12405SJérôme Glisse /* 277c0b12405SJérôme Glisse * hmm_mirror_unregister() - unregister a mirror 278c0b12405SJérôme Glisse * 279085ea250SRalph Campbell * @mirror: mirror struct to unregister 280c0b12405SJérôme Glisse * 281c0b12405SJérôme Glisse * Stop mirroring a process address space, and cleanup. 282c0b12405SJérôme Glisse */ 283c0b12405SJérôme Glisse void hmm_mirror_unregister(struct hmm_mirror *mirror) 284c0b12405SJérôme Glisse { 285704f3f2cSJérôme Glisse struct hmm *hmm = READ_ONCE(mirror->hmm); 286c0b12405SJérôme Glisse 287704f3f2cSJérôme Glisse if (hmm == NULL) 288c01cbba2SJérôme Glisse return; 289c01cbba2SJérôme Glisse 290c0b12405SJérôme Glisse down_write(&hmm->mirrors_sem); 291e1401513SRalph Campbell list_del_init(&mirror->list); 292704f3f2cSJérôme Glisse /* To protect us against double unregister ... */ 293c01cbba2SJérôme Glisse mirror->hmm = NULL; 294c0b12405SJérôme Glisse up_write(&hmm->mirrors_sem); 295c01cbba2SJérôme Glisse 296704f3f2cSJérôme Glisse hmm_put(hmm); 297c0b12405SJérôme Glisse } 298c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_unregister); 299da4c3c73SJérôme Glisse 30074eee180SJérôme Glisse struct hmm_vma_walk { 30174eee180SJérôme Glisse struct hmm_range *range; 302992de9a8SJérôme Glisse struct dev_pagemap *pgmap; 30374eee180SJérôme Glisse unsigned long last; 30474eee180SJérôme Glisse bool fault; 30574eee180SJérôme Glisse bool block; 30674eee180SJérôme Glisse }; 30774eee180SJérôme Glisse 3082aee09d8SJérôme Glisse static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr, 3092aee09d8SJérôme Glisse bool write_fault, uint64_t *pfn) 31074eee180SJérôme Glisse { 3119b1ae605SKuehling, Felix unsigned int flags = FAULT_FLAG_REMOTE; 31274eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 313f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 31474eee180SJérôme Glisse struct vm_area_struct *vma = walk->vma; 31550a7ca3cSSouptick Joarder vm_fault_t ret; 31674eee180SJérôme Glisse 31774eee180SJérôme Glisse flags |= hmm_vma_walk->block ? 0 : FAULT_FLAG_ALLOW_RETRY; 3182aee09d8SJérôme Glisse flags |= write_fault ? FAULT_FLAG_WRITE : 0; 31950a7ca3cSSouptick Joarder ret = handle_mm_fault(vma, addr, flags); 32050a7ca3cSSouptick Joarder if (ret & VM_FAULT_RETRY) 32173231612SJérôme Glisse return -EAGAIN; 32250a7ca3cSSouptick Joarder if (ret & VM_FAULT_ERROR) { 323f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 32474eee180SJérôme Glisse return -EFAULT; 32574eee180SJérôme Glisse } 32674eee180SJérôme Glisse 32773231612SJérôme Glisse return -EBUSY; 32874eee180SJérôme Glisse } 32974eee180SJérôme Glisse 330da4c3c73SJérôme Glisse static int hmm_pfns_bad(unsigned long addr, 331da4c3c73SJérôme Glisse unsigned long end, 332da4c3c73SJérôme Glisse struct mm_walk *walk) 333da4c3c73SJérôme Glisse { 334c719547fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 335c719547fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 336ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 337da4c3c73SJérôme Glisse unsigned long i; 338da4c3c73SJérôme Glisse 339da4c3c73SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 340da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, i++) 341f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_ERROR]; 342da4c3c73SJérôme Glisse 343da4c3c73SJérôme Glisse return 0; 344da4c3c73SJérôme Glisse } 345da4c3c73SJérôme Glisse 3465504ed29SJérôme Glisse /* 3475504ed29SJérôme Glisse * hmm_vma_walk_hole() - handle a range lacking valid pmd or pte(s) 3485504ed29SJérôme Glisse * @start: range virtual start address (inclusive) 3495504ed29SJérôme Glisse * @end: range virtual end address (exclusive) 3502aee09d8SJérôme Glisse * @fault: should we fault or not ? 3512aee09d8SJérôme Glisse * @write_fault: write fault ? 3525504ed29SJérôme Glisse * @walk: mm_walk structure 353085ea250SRalph Campbell * Return: 0 on success, -EBUSY after page fault, or page fault error 3545504ed29SJérôme Glisse * 3555504ed29SJérôme Glisse * This function will be called whenever pmd_none() or pte_none() returns true, 3565504ed29SJérôme Glisse * or whenever there is no page directory covering the virtual address range. 3575504ed29SJérôme Glisse */ 3582aee09d8SJérôme Glisse static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end, 3592aee09d8SJérôme Glisse bool fault, bool write_fault, 360da4c3c73SJérôme Glisse struct mm_walk *walk) 361da4c3c73SJérôme Glisse { 36274eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 36374eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 364ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 36563d5066fSJérôme Glisse unsigned long i, page_size; 366da4c3c73SJérôme Glisse 36774eee180SJérôme Glisse hmm_vma_walk->last = addr; 36863d5066fSJérôme Glisse page_size = hmm_range_page_size(range); 36963d5066fSJérôme Glisse i = (addr - range->start) >> range->page_shift; 37063d5066fSJérôme Glisse 37163d5066fSJérôme Glisse for (; addr < end; addr += page_size, i++) { 372f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_NONE]; 3732aee09d8SJérôme Glisse if (fault || write_fault) { 37474eee180SJérôme Glisse int ret; 375da4c3c73SJérôme Glisse 3762aee09d8SJérôme Glisse ret = hmm_vma_do_fault(walk, addr, write_fault, 3772aee09d8SJérôme Glisse &pfns[i]); 37873231612SJérôme Glisse if (ret != -EBUSY) 37974eee180SJérôme Glisse return ret; 38074eee180SJérôme Glisse } 38174eee180SJérôme Glisse } 38274eee180SJérôme Glisse 38373231612SJérôme Glisse return (fault || write_fault) ? -EBUSY : 0; 3842aee09d8SJérôme Glisse } 3852aee09d8SJérôme Glisse 3862aee09d8SJérôme Glisse static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 3872aee09d8SJérôme Glisse uint64_t pfns, uint64_t cpu_flags, 3882aee09d8SJérôme Glisse bool *fault, bool *write_fault) 3892aee09d8SJérôme Glisse { 390f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 391f88a1e90SJérôme Glisse 3922aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) 3932aee09d8SJérôme Glisse return; 3942aee09d8SJérôme Glisse 395023a019aSJérôme Glisse /* 396023a019aSJérôme Glisse * So we not only consider the individual per page request we also 397023a019aSJérôme Glisse * consider the default flags requested for the range. The API can 398023a019aSJérôme Glisse * be use in 2 fashions. The first one where the HMM user coalesce 399023a019aSJérôme Glisse * multiple page fault into one request and set flags per pfns for 400023a019aSJérôme Glisse * of those faults. The second one where the HMM user want to pre- 401023a019aSJérôme Glisse * fault a range with specific flags. For the latter one it is a 402023a019aSJérôme Glisse * waste to have the user pre-fill the pfn arrays with a default 403023a019aSJérôme Glisse * flags value. 404023a019aSJérôme Glisse */ 405023a019aSJérôme Glisse pfns = (pfns & range->pfn_flags_mask) | range->default_flags; 406023a019aSJérôme Glisse 4072aee09d8SJérôme Glisse /* We aren't ask to do anything ... */ 408f88a1e90SJérôme Glisse if (!(pfns & range->flags[HMM_PFN_VALID])) 4092aee09d8SJérôme Glisse return; 410f88a1e90SJérôme Glisse /* If this is device memory than only fault if explicitly requested */ 411f88a1e90SJérôme Glisse if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) { 412f88a1e90SJérôme Glisse /* Do we fault on device memory ? */ 413f88a1e90SJérôme Glisse if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) { 414f88a1e90SJérôme Glisse *write_fault = pfns & range->flags[HMM_PFN_WRITE]; 415f88a1e90SJérôme Glisse *fault = true; 416f88a1e90SJérôme Glisse } 4172aee09d8SJérôme Glisse return; 4182aee09d8SJérôme Glisse } 419f88a1e90SJérôme Glisse 420f88a1e90SJérôme Glisse /* If CPU page table is not valid then we need to fault */ 421f88a1e90SJérôme Glisse *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]); 422f88a1e90SJérôme Glisse /* Need to write fault ? */ 423f88a1e90SJérôme Glisse if ((pfns & range->flags[HMM_PFN_WRITE]) && 424f88a1e90SJérôme Glisse !(cpu_flags & range->flags[HMM_PFN_WRITE])) { 425f88a1e90SJérôme Glisse *write_fault = true; 4262aee09d8SJérôme Glisse *fault = true; 4272aee09d8SJérôme Glisse } 4282aee09d8SJérôme Glisse } 4292aee09d8SJérôme Glisse 4302aee09d8SJérôme Glisse static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 4312aee09d8SJérôme Glisse const uint64_t *pfns, unsigned long npages, 4322aee09d8SJérôme Glisse uint64_t cpu_flags, bool *fault, 4332aee09d8SJérôme Glisse bool *write_fault) 4342aee09d8SJérôme Glisse { 4352aee09d8SJérôme Glisse unsigned long i; 4362aee09d8SJérôme Glisse 4372aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) { 4382aee09d8SJérôme Glisse *fault = *write_fault = false; 4392aee09d8SJérôme Glisse return; 4402aee09d8SJérôme Glisse } 4412aee09d8SJérôme Glisse 442a3e0d41cSJérôme Glisse *fault = *write_fault = false; 4432aee09d8SJérôme Glisse for (i = 0; i < npages; ++i) { 4442aee09d8SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags, 4452aee09d8SJérôme Glisse fault, write_fault); 446a3e0d41cSJérôme Glisse if ((*write_fault)) 4472aee09d8SJérôme Glisse return; 4482aee09d8SJérôme Glisse } 4492aee09d8SJérôme Glisse } 4502aee09d8SJérôme Glisse 4512aee09d8SJérôme Glisse static int hmm_vma_walk_hole(unsigned long addr, unsigned long end, 4522aee09d8SJérôme Glisse struct mm_walk *walk) 4532aee09d8SJérôme Glisse { 4542aee09d8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 4552aee09d8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 4562aee09d8SJérôme Glisse bool fault, write_fault; 4572aee09d8SJérôme Glisse unsigned long i, npages; 4582aee09d8SJérôme Glisse uint64_t *pfns; 4592aee09d8SJérôme Glisse 4602aee09d8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 4612aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 4622aee09d8SJérôme Glisse pfns = &range->pfns[i]; 4632aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 4642aee09d8SJérôme Glisse 0, &fault, &write_fault); 4652aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 4662aee09d8SJérôme Glisse } 4672aee09d8SJérôme Glisse 468f88a1e90SJérôme Glisse static inline uint64_t pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd) 4692aee09d8SJérôme Glisse { 4702aee09d8SJérôme Glisse if (pmd_protnone(pmd)) 4712aee09d8SJérôme Glisse return 0; 472f88a1e90SJérôme Glisse return pmd_write(pmd) ? range->flags[HMM_PFN_VALID] | 473f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 474f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 475da4c3c73SJérôme Glisse } 476da4c3c73SJérôme Glisse 477992de9a8SJérôme Glisse static inline uint64_t pud_to_hmm_pfn_flags(struct hmm_range *range, pud_t pud) 478992de9a8SJérôme Glisse { 479992de9a8SJérôme Glisse if (!pud_present(pud)) 480992de9a8SJérôme Glisse return 0; 481992de9a8SJérôme Glisse return pud_write(pud) ? range->flags[HMM_PFN_VALID] | 482992de9a8SJérôme Glisse range->flags[HMM_PFN_WRITE] : 483992de9a8SJérôme Glisse range->flags[HMM_PFN_VALID]; 484992de9a8SJérôme Glisse } 485992de9a8SJérôme Glisse 48653f5c3f4SJérôme Glisse static int hmm_vma_handle_pmd(struct mm_walk *walk, 48753f5c3f4SJérôme Glisse unsigned long addr, 48853f5c3f4SJérôme Glisse unsigned long end, 48953f5c3f4SJérôme Glisse uint64_t *pfns, 49053f5c3f4SJérôme Glisse pmd_t pmd) 49153f5c3f4SJérôme Glisse { 492992de9a8SJérôme Glisse #ifdef CONFIG_TRANSPARENT_HUGEPAGE 49353f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 494f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 4952aee09d8SJérôme Glisse unsigned long pfn, npages, i; 4962aee09d8SJérôme Glisse bool fault, write_fault; 497f88a1e90SJérôme Glisse uint64_t cpu_flags; 49853f5c3f4SJérôme Glisse 4992aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 500f88a1e90SJérôme Glisse cpu_flags = pmd_to_hmm_pfn_flags(range, pmd); 5012aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags, 5022aee09d8SJérôme Glisse &fault, &write_fault); 50353f5c3f4SJérôme Glisse 5042aee09d8SJérôme Glisse if (pmd_protnone(pmd) || fault || write_fault) 5052aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 50653f5c3f4SJérôme Glisse 50753f5c3f4SJérôme Glisse pfn = pmd_pfn(pmd) + pte_index(addr); 508992de9a8SJérôme Glisse for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { 509992de9a8SJérôme Glisse if (pmd_devmap(pmd)) { 510992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 511992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 512992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 513992de9a8SJérôme Glisse return -EBUSY; 514992de9a8SJérôme Glisse } 515391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; 516992de9a8SJérôme Glisse } 517992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 518992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 519992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 520992de9a8SJérôme Glisse } 52153f5c3f4SJérôme Glisse hmm_vma_walk->last = end; 52253f5c3f4SJérôme Glisse return 0; 523992de9a8SJérôme Glisse #else 524992de9a8SJérôme Glisse /* If THP is not enabled then we should never reach that code ! */ 525992de9a8SJérôme Glisse return -EINVAL; 526992de9a8SJérôme Glisse #endif 52753f5c3f4SJérôme Glisse } 52853f5c3f4SJérôme Glisse 529f88a1e90SJérôme Glisse static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte) 5302aee09d8SJérôme Glisse { 531789c2af8SPhilip Yang if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte)) 5322aee09d8SJérôme Glisse return 0; 533f88a1e90SJérôme Glisse return pte_write(pte) ? range->flags[HMM_PFN_VALID] | 534f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 535f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 5362aee09d8SJérôme Glisse } 5372aee09d8SJérôme Glisse 53853f5c3f4SJérôme Glisse static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, 53953f5c3f4SJérôme Glisse unsigned long end, pmd_t *pmdp, pte_t *ptep, 54053f5c3f4SJérôme Glisse uint64_t *pfn) 54153f5c3f4SJérôme Glisse { 54253f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 543f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 54453f5c3f4SJérôme Glisse struct vm_area_struct *vma = walk->vma; 5452aee09d8SJérôme Glisse bool fault, write_fault; 5462aee09d8SJérôme Glisse uint64_t cpu_flags; 54753f5c3f4SJérôme Glisse pte_t pte = *ptep; 548f88a1e90SJérôme Glisse uint64_t orig_pfn = *pfn; 54953f5c3f4SJérôme Glisse 550f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_NONE]; 55173231612SJérôme Glisse fault = write_fault = false; 55253f5c3f4SJérôme Glisse 55353f5c3f4SJérôme Glisse if (pte_none(pte)) { 55473231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, 55573231612SJérôme Glisse &fault, &write_fault); 5562aee09d8SJérôme Glisse if (fault || write_fault) 55753f5c3f4SJérôme Glisse goto fault; 55853f5c3f4SJérôme Glisse return 0; 55953f5c3f4SJérôme Glisse } 56053f5c3f4SJérôme Glisse 56153f5c3f4SJérôme Glisse if (!pte_present(pte)) { 56253f5c3f4SJérôme Glisse swp_entry_t entry = pte_to_swp_entry(pte); 56353f5c3f4SJérôme Glisse 56453f5c3f4SJérôme Glisse if (!non_swap_entry(entry)) { 5652aee09d8SJérôme Glisse if (fault || write_fault) 56653f5c3f4SJérôme Glisse goto fault; 56753f5c3f4SJérôme Glisse return 0; 56853f5c3f4SJérôme Glisse } 56953f5c3f4SJérôme Glisse 57053f5c3f4SJérôme Glisse /* 57153f5c3f4SJérôme Glisse * This is a special swap entry, ignore migration, use 57253f5c3f4SJérôme Glisse * device and report anything else as error. 57353f5c3f4SJérôme Glisse */ 57453f5c3f4SJérôme Glisse if (is_device_private_entry(entry)) { 575f88a1e90SJérôme Glisse cpu_flags = range->flags[HMM_PFN_VALID] | 576f88a1e90SJérôme Glisse range->flags[HMM_PFN_DEVICE_PRIVATE]; 5772aee09d8SJérôme Glisse cpu_flags |= is_write_device_private_entry(entry) ? 578f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 0; 579f88a1e90SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 580f88a1e90SJérôme Glisse &fault, &write_fault); 581f88a1e90SJérôme Glisse if (fault || write_fault) 582f88a1e90SJérôme Glisse goto fault; 583391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, 584391aab11SJérôme Glisse swp_offset(entry)); 585f88a1e90SJérôme Glisse *pfn |= cpu_flags; 58653f5c3f4SJérôme Glisse return 0; 58753f5c3f4SJérôme Glisse } 58853f5c3f4SJérôme Glisse 58953f5c3f4SJérôme Glisse if (is_migration_entry(entry)) { 5902aee09d8SJérôme Glisse if (fault || write_fault) { 59153f5c3f4SJérôme Glisse pte_unmap(ptep); 59253f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 59353f5c3f4SJérôme Glisse migration_entry_wait(vma->vm_mm, 59453f5c3f4SJérôme Glisse pmdp, addr); 59573231612SJérôme Glisse return -EBUSY; 59653f5c3f4SJérôme Glisse } 59753f5c3f4SJérôme Glisse return 0; 59853f5c3f4SJérôme Glisse } 59953f5c3f4SJérôme Glisse 60053f5c3f4SJérôme Glisse /* Report error for everything else */ 601f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 60253f5c3f4SJérôme Glisse return -EFAULT; 60373231612SJérôme Glisse } else { 60473231612SJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, pte); 60573231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 60673231612SJérôme Glisse &fault, &write_fault); 60753f5c3f4SJérôme Glisse } 60853f5c3f4SJérôme Glisse 6092aee09d8SJérôme Glisse if (fault || write_fault) 61053f5c3f4SJérôme Glisse goto fault; 61153f5c3f4SJérôme Glisse 612992de9a8SJérôme Glisse if (pte_devmap(pte)) { 613992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pte_pfn(pte), 614992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 615992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 616992de9a8SJérôme Glisse return -EBUSY; 617992de9a8SJérôme Glisse } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) { 618992de9a8SJérôme Glisse *pfn = range->values[HMM_PFN_SPECIAL]; 619992de9a8SJérôme Glisse return -EFAULT; 620992de9a8SJérôme Glisse } 621992de9a8SJérôme Glisse 622391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags; 62353f5c3f4SJérôme Glisse return 0; 62453f5c3f4SJérôme Glisse 62553f5c3f4SJérôme Glisse fault: 626992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 627992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 628992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 629992de9a8SJérôme Glisse } 63053f5c3f4SJérôme Glisse pte_unmap(ptep); 63153f5c3f4SJérôme Glisse /* Fault any virtual address we were asked to fault */ 6322aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 63353f5c3f4SJérôme Glisse } 63453f5c3f4SJérôme Glisse 635da4c3c73SJérôme Glisse static int hmm_vma_walk_pmd(pmd_t *pmdp, 636da4c3c73SJérôme Glisse unsigned long start, 637da4c3c73SJérôme Glisse unsigned long end, 638da4c3c73SJérôme Glisse struct mm_walk *walk) 639da4c3c73SJérôme Glisse { 64074eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 64174eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 642d08faca0SJérôme Glisse struct vm_area_struct *vma = walk->vma; 643ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 644da4c3c73SJérôme Glisse unsigned long addr = start, i; 645da4c3c73SJérôme Glisse pte_t *ptep; 646da4c3c73SJérôme Glisse pmd_t pmd; 647da4c3c73SJérôme Glisse 648d08faca0SJérôme Glisse 649d08faca0SJérôme Glisse again: 650d08faca0SJérôme Glisse pmd = READ_ONCE(*pmdp); 651d08faca0SJérôme Glisse if (pmd_none(pmd)) 652d08faca0SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 653d08faca0SJérôme Glisse 654d08faca0SJérôme Glisse if (pmd_huge(pmd) && (range->vma->vm_flags & VM_HUGETLB)) 655d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 656d08faca0SJérôme Glisse 657d08faca0SJérôme Glisse if (thp_migration_supported() && is_pmd_migration_entry(pmd)) { 658d08faca0SJérôme Glisse bool fault, write_fault; 659d08faca0SJérôme Glisse unsigned long npages; 660d08faca0SJérôme Glisse uint64_t *pfns; 661d08faca0SJérôme Glisse 662d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 663d08faca0SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 664d08faca0SJérôme Glisse pfns = &range->pfns[i]; 665d08faca0SJérôme Glisse 666d08faca0SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 667d08faca0SJérôme Glisse 0, &fault, &write_fault); 668d08faca0SJérôme Glisse if (fault || write_fault) { 669d08faca0SJérôme Glisse hmm_vma_walk->last = addr; 670d08faca0SJérôme Glisse pmd_migration_entry_wait(vma->vm_mm, pmdp); 67173231612SJérôme Glisse return -EBUSY; 672d08faca0SJérôme Glisse } 673d08faca0SJérôme Glisse return 0; 674d08faca0SJérôme Glisse } else if (!pmd_present(pmd)) 675d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 676d08faca0SJérôme Glisse 677d08faca0SJérôme Glisse if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) { 678da4c3c73SJérôme Glisse /* 679da4c3c73SJérôme Glisse * No need to take pmd_lock here, even if some other threads 680da4c3c73SJérôme Glisse * is splitting the huge pmd we will get that event through 681da4c3c73SJérôme Glisse * mmu_notifier callback. 682da4c3c73SJérôme Glisse * 683da4c3c73SJérôme Glisse * So just read pmd value and check again its a transparent 684da4c3c73SJérôme Glisse * huge or device mapping one and compute corresponding pfn 685da4c3c73SJérôme Glisse * values. 686da4c3c73SJérôme Glisse */ 687da4c3c73SJérôme Glisse pmd = pmd_read_atomic(pmdp); 688da4c3c73SJérôme Glisse barrier(); 689da4c3c73SJérôme Glisse if (!pmd_devmap(pmd) && !pmd_trans_huge(pmd)) 690da4c3c73SJérôme Glisse goto again; 691da4c3c73SJérôme Glisse 692d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 69353f5c3f4SJérôme Glisse return hmm_vma_handle_pmd(walk, addr, end, &pfns[i], pmd); 694da4c3c73SJérôme Glisse } 695da4c3c73SJérôme Glisse 696d08faca0SJérôme Glisse /* 697d08faca0SJérôme Glisse * We have handled all the valid case above ie either none, migration, 698d08faca0SJérôme Glisse * huge or transparent huge. At this point either it is a valid pmd 699d08faca0SJérôme Glisse * entry pointing to pte directory or it is a bad pmd that will not 700d08faca0SJérôme Glisse * recover. 701d08faca0SJérôme Glisse */ 702d08faca0SJérôme Glisse if (pmd_bad(pmd)) 703da4c3c73SJérôme Glisse return hmm_pfns_bad(start, end, walk); 704da4c3c73SJérôme Glisse 705da4c3c73SJérôme Glisse ptep = pte_offset_map(pmdp, addr); 706d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 707da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, ptep++, i++) { 70853f5c3f4SJérôme Glisse int r; 709da4c3c73SJérôme Glisse 71053f5c3f4SJérôme Glisse r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, &pfns[i]); 71153f5c3f4SJérôme Glisse if (r) { 71253f5c3f4SJérôme Glisse /* hmm_vma_handle_pte() did unmap pte directory */ 71374eee180SJérôme Glisse hmm_vma_walk->last = addr; 71453f5c3f4SJérôme Glisse return r; 71574eee180SJérôme Glisse } 716da4c3c73SJérôme Glisse } 717992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 718992de9a8SJérôme Glisse /* 719992de9a8SJérôme Glisse * We do put_dev_pagemap() here and not in hmm_vma_handle_pte() 720992de9a8SJérôme Glisse * so that we can leverage get_dev_pagemap() optimization which 721992de9a8SJérôme Glisse * will not re-take a reference on a pgmap if we already have 722992de9a8SJérôme Glisse * one. 723992de9a8SJérôme Glisse */ 724992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 725992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 726992de9a8SJérôme Glisse } 727da4c3c73SJérôme Glisse pte_unmap(ptep - 1); 728da4c3c73SJérôme Glisse 72953f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 730da4c3c73SJérôme Glisse return 0; 731da4c3c73SJérôme Glisse } 732da4c3c73SJérôme Glisse 733992de9a8SJérôme Glisse static int hmm_vma_walk_pud(pud_t *pudp, 734992de9a8SJérôme Glisse unsigned long start, 735992de9a8SJérôme Glisse unsigned long end, 736992de9a8SJérôme Glisse struct mm_walk *walk) 737992de9a8SJérôme Glisse { 738992de9a8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 739992de9a8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 740992de9a8SJérôme Glisse unsigned long addr = start, next; 741992de9a8SJérôme Glisse pmd_t *pmdp; 742992de9a8SJérôme Glisse pud_t pud; 743992de9a8SJérôme Glisse int ret; 744992de9a8SJérôme Glisse 745992de9a8SJérôme Glisse again: 746992de9a8SJérôme Glisse pud = READ_ONCE(*pudp); 747992de9a8SJérôme Glisse if (pud_none(pud)) 748992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 749992de9a8SJérôme Glisse 750992de9a8SJérôme Glisse if (pud_huge(pud) && pud_devmap(pud)) { 751992de9a8SJérôme Glisse unsigned long i, npages, pfn; 752992de9a8SJérôme Glisse uint64_t *pfns, cpu_flags; 753992de9a8SJérôme Glisse bool fault, write_fault; 754992de9a8SJérôme Glisse 755992de9a8SJérôme Glisse if (!pud_present(pud)) 756992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 757992de9a8SJérôme Glisse 758992de9a8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 759992de9a8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 760992de9a8SJérôme Glisse pfns = &range->pfns[i]; 761992de9a8SJérôme Glisse 762992de9a8SJérôme Glisse cpu_flags = pud_to_hmm_pfn_flags(range, pud); 763992de9a8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 764992de9a8SJérôme Glisse cpu_flags, &fault, &write_fault); 765992de9a8SJérôme Glisse if (fault || write_fault) 766992de9a8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, 767992de9a8SJérôme Glisse write_fault, walk); 768992de9a8SJérôme Glisse 769992de9a8SJérôme Glisse pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); 770992de9a8SJérôme Glisse for (i = 0; i < npages; ++i, ++pfn) { 771992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 772992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 773992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 774992de9a8SJérôme Glisse return -EBUSY; 775391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 776391aab11SJérôme Glisse cpu_flags; 777992de9a8SJérôme Glisse } 778992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 779992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 780992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 781992de9a8SJérôme Glisse } 782992de9a8SJérôme Glisse hmm_vma_walk->last = end; 783992de9a8SJérôme Glisse return 0; 784992de9a8SJérôme Glisse } 785992de9a8SJérôme Glisse 786992de9a8SJérôme Glisse split_huge_pud(walk->vma, pudp, addr); 787992de9a8SJérôme Glisse if (pud_none(*pudp)) 788992de9a8SJérôme Glisse goto again; 789992de9a8SJérôme Glisse 790992de9a8SJérôme Glisse pmdp = pmd_offset(pudp, addr); 791992de9a8SJérôme Glisse do { 792992de9a8SJérôme Glisse next = pmd_addr_end(addr, end); 793992de9a8SJérôme Glisse ret = hmm_vma_walk_pmd(pmdp, addr, next, walk); 794992de9a8SJérôme Glisse if (ret) 795992de9a8SJérôme Glisse return ret; 796992de9a8SJérôme Glisse } while (pmdp++, addr = next, addr != end); 797992de9a8SJérôme Glisse 798992de9a8SJérôme Glisse return 0; 799992de9a8SJérôme Glisse } 800992de9a8SJérôme Glisse 80163d5066fSJérôme Glisse static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, 80263d5066fSJérôme Glisse unsigned long start, unsigned long end, 80363d5066fSJérôme Glisse struct mm_walk *walk) 80463d5066fSJérôme Glisse { 80563d5066fSJérôme Glisse #ifdef CONFIG_HUGETLB_PAGE 80663d5066fSJérôme Glisse unsigned long addr = start, i, pfn, mask, size, pfn_inc; 80763d5066fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 80863d5066fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 80963d5066fSJérôme Glisse struct vm_area_struct *vma = walk->vma; 81063d5066fSJérôme Glisse struct hstate *h = hstate_vma(vma); 81163d5066fSJérôme Glisse uint64_t orig_pfn, cpu_flags; 81263d5066fSJérôme Glisse bool fault, write_fault; 81363d5066fSJérôme Glisse spinlock_t *ptl; 81463d5066fSJérôme Glisse pte_t entry; 81563d5066fSJérôme Glisse int ret = 0; 81663d5066fSJérôme Glisse 81763d5066fSJérôme Glisse size = 1UL << huge_page_shift(h); 81863d5066fSJérôme Glisse mask = size - 1; 81963d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) { 82063d5066fSJérôme Glisse /* Make sure we are looking at full page. */ 82163d5066fSJérôme Glisse if (start & mask) 82263d5066fSJérôme Glisse return -EINVAL; 82363d5066fSJérôme Glisse if (end < (start + size)) 82463d5066fSJérôme Glisse return -EINVAL; 82563d5066fSJérôme Glisse pfn_inc = size >> PAGE_SHIFT; 82663d5066fSJérôme Glisse } else { 82763d5066fSJérôme Glisse pfn_inc = 1; 82863d5066fSJérôme Glisse size = PAGE_SIZE; 82963d5066fSJérôme Glisse } 83063d5066fSJérôme Glisse 83163d5066fSJérôme Glisse 83263d5066fSJérôme Glisse ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); 83363d5066fSJérôme Glisse entry = huge_ptep_get(pte); 83463d5066fSJérôme Glisse 83563d5066fSJérôme Glisse i = (start - range->start) >> range->page_shift; 83663d5066fSJérôme Glisse orig_pfn = range->pfns[i]; 83763d5066fSJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 83863d5066fSJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, entry); 83963d5066fSJérôme Glisse fault = write_fault = false; 84063d5066fSJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 84163d5066fSJérôme Glisse &fault, &write_fault); 84263d5066fSJérôme Glisse if (fault || write_fault) { 84363d5066fSJérôme Glisse ret = -ENOENT; 84463d5066fSJérôme Glisse goto unlock; 84563d5066fSJérôme Glisse } 84663d5066fSJérôme Glisse 84763d5066fSJérôme Glisse pfn = pte_pfn(entry) + ((start & mask) >> range->page_shift); 84863d5066fSJérôme Glisse for (; addr < end; addr += size, i++, pfn += pfn_inc) 849391aab11SJérôme Glisse range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 850391aab11SJérôme Glisse cpu_flags; 85163d5066fSJérôme Glisse hmm_vma_walk->last = end; 85263d5066fSJérôme Glisse 85363d5066fSJérôme Glisse unlock: 85463d5066fSJérôme Glisse spin_unlock(ptl); 85563d5066fSJérôme Glisse 85663d5066fSJérôme Glisse if (ret == -ENOENT) 85763d5066fSJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 85863d5066fSJérôme Glisse 85963d5066fSJérôme Glisse return ret; 86063d5066fSJérôme Glisse #else /* CONFIG_HUGETLB_PAGE */ 86163d5066fSJérôme Glisse return -EINVAL; 86263d5066fSJérôme Glisse #endif 86363d5066fSJérôme Glisse } 86463d5066fSJérôme Glisse 865f88a1e90SJérôme Glisse static void hmm_pfns_clear(struct hmm_range *range, 866f88a1e90SJérôme Glisse uint64_t *pfns, 86733cd47dcSJérôme Glisse unsigned long addr, 86833cd47dcSJérôme Glisse unsigned long end) 86933cd47dcSJérôme Glisse { 87033cd47dcSJérôme Glisse for (; addr < end; addr += PAGE_SIZE, pfns++) 871f88a1e90SJérôme Glisse *pfns = range->values[HMM_PFN_NONE]; 87233cd47dcSJérôme Glisse } 87333cd47dcSJérôme Glisse 874da4c3c73SJérôme Glisse /* 875a3e0d41cSJérôme Glisse * hmm_range_register() - start tracking change to CPU page table over a range 876a3e0d41cSJérôme Glisse * @range: range 877a3e0d41cSJérôme Glisse * @mm: the mm struct for the range of virtual address 878a3e0d41cSJérôme Glisse * @start: start virtual address (inclusive) 879a3e0d41cSJérôme Glisse * @end: end virtual address (exclusive) 88063d5066fSJérôme Glisse * @page_shift: expect page shift for the range 881a3e0d41cSJérôme Glisse * Returns 0 on success, -EFAULT if the address space is no longer valid 882a3e0d41cSJérôme Glisse * 883a3e0d41cSJérôme Glisse * Track updates to the CPU page table see include/linux/hmm.h 884a3e0d41cSJérôme Glisse */ 885a3e0d41cSJérôme Glisse int hmm_range_register(struct hmm_range *range, 886e36acfe6SJason Gunthorpe struct hmm_mirror *mirror, 887a3e0d41cSJérôme Glisse unsigned long start, 88863d5066fSJérôme Glisse unsigned long end, 88963d5066fSJérôme Glisse unsigned page_shift) 890a3e0d41cSJérôme Glisse { 89163d5066fSJérôme Glisse unsigned long mask = ((1UL << page_shift) - 1UL); 892e36acfe6SJason Gunthorpe struct hmm *hmm = mirror->hmm; 89363d5066fSJérôme Glisse 894a3e0d41cSJérôme Glisse range->valid = false; 895a3e0d41cSJérôme Glisse range->hmm = NULL; 896a3e0d41cSJérôme Glisse 89763d5066fSJérôme Glisse if ((start & mask) || (end & mask)) 89863d5066fSJérôme Glisse return -EINVAL; 89963d5066fSJérôme Glisse if (start >= end) 900a3e0d41cSJérôme Glisse return -EINVAL; 901a3e0d41cSJérôme Glisse 90263d5066fSJérôme Glisse range->page_shift = page_shift; 903a3e0d41cSJérôme Glisse range->start = start; 904a3e0d41cSJérôme Glisse range->end = end; 905a3e0d41cSJérôme Glisse 906a3e0d41cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 907e36acfe6SJason Gunthorpe if (hmm->mm == NULL || hmm->dead) 908a3e0d41cSJérôme Glisse return -EFAULT; 909a3e0d41cSJérôme Glisse 910085ea250SRalph Campbell /* Initialize range to track CPU page table updates. */ 911085ea250SRalph Campbell mutex_lock(&hmm->lock); 912a3e0d41cSJérôme Glisse 913085ea250SRalph Campbell range->hmm = hmm; 914e36acfe6SJason Gunthorpe kref_get(&hmm->kref); 915*157816f3SJason Gunthorpe list_add(&range->list, &hmm->ranges); 916a3e0d41cSJérôme Glisse 917a3e0d41cSJérôme Glisse /* 918a3e0d41cSJérôme Glisse * If there are any concurrent notifiers we have to wait for them for 919a3e0d41cSJérôme Glisse * the range to be valid (see hmm_range_wait_until_valid()). 920a3e0d41cSJérôme Glisse */ 921085ea250SRalph Campbell if (!hmm->notifiers) 922a3e0d41cSJérôme Glisse range->valid = true; 923085ea250SRalph Campbell mutex_unlock(&hmm->lock); 924a3e0d41cSJérôme Glisse 925a3e0d41cSJérôme Glisse return 0; 926a3e0d41cSJérôme Glisse } 927a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_register); 928a3e0d41cSJérôme Glisse 929a3e0d41cSJérôme Glisse /* 930a3e0d41cSJérôme Glisse * hmm_range_unregister() - stop tracking change to CPU page table over a range 931a3e0d41cSJérôme Glisse * @range: range 932a3e0d41cSJérôme Glisse * 933a3e0d41cSJérôme Glisse * Range struct is used to track updates to the CPU page table after a call to 934a3e0d41cSJérôme Glisse * hmm_range_register(). See include/linux/hmm.h for how to use it. 935a3e0d41cSJérôme Glisse */ 936a3e0d41cSJérôme Glisse void hmm_range_unregister(struct hmm_range *range) 937a3e0d41cSJérôme Glisse { 938085ea250SRalph Campbell struct hmm *hmm = range->hmm; 939085ea250SRalph Campbell 940a3e0d41cSJérôme Glisse /* Sanity check this really should not happen. */ 941085ea250SRalph Campbell if (hmm == NULL || range->end <= range->start) 942a3e0d41cSJérôme Glisse return; 943a3e0d41cSJérôme Glisse 944085ea250SRalph Campbell mutex_lock(&hmm->lock); 945*157816f3SJason Gunthorpe list_del(&range->list); 946085ea250SRalph Campbell mutex_unlock(&hmm->lock); 947a3e0d41cSJérôme Glisse 948a3e0d41cSJérôme Glisse /* Drop reference taken by hmm_range_register() */ 949a3e0d41cSJérôme Glisse range->valid = false; 950085ea250SRalph Campbell hmm_put(hmm); 951a3e0d41cSJérôme Glisse range->hmm = NULL; 952a3e0d41cSJérôme Glisse } 953a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_unregister); 954a3e0d41cSJérôme Glisse 955a3e0d41cSJérôme Glisse /* 95625f23a0cSJérôme Glisse * hmm_range_snapshot() - snapshot CPU page table for a range 95725f23a0cSJérôme Glisse * @range: range 958085ea250SRalph Campbell * Return: -EINVAL if invalid argument, -ENOMEM out of memory, -EPERM invalid 959a3e0d41cSJérôme Glisse * permission (for instance asking for write and range is read only), 960a3e0d41cSJérôme Glisse * -EAGAIN if you need to retry, -EFAULT invalid (ie either no valid 961a3e0d41cSJérôme Glisse * vma or it is illegal to access that range), number of valid pages 962a3e0d41cSJérôme Glisse * in range->pfns[] (from range start address). 963da4c3c73SJérôme Glisse * 964da4c3c73SJérôme Glisse * This snapshots the CPU page table for a range of virtual addresses. Snapshot 965a3e0d41cSJérôme Glisse * validity is tracked by range struct. See in include/linux/hmm.h for example 966a3e0d41cSJérôme Glisse * on how to use. 967da4c3c73SJérôme Glisse */ 96825f23a0cSJérôme Glisse long hmm_range_snapshot(struct hmm_range *range) 969da4c3c73SJérôme Glisse { 97063d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 971a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 97274eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 973a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 974a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 975da4c3c73SJérôme Glisse struct mm_walk mm_walk; 976704f3f2cSJérôme Glisse 977704f3f2cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 978a3e0d41cSJérôme Glisse if (hmm->mm == NULL || hmm->dead) 979a3e0d41cSJérôme Glisse return -EFAULT; 980da4c3c73SJérôme Glisse 981a3e0d41cSJérôme Glisse do { 982a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 983a3e0d41cSJérôme Glisse if (!range->valid) 984a3e0d41cSJérôme Glisse return -EAGAIN; 985a3e0d41cSJérôme Glisse 986a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 98763d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 988a3e0d41cSJérôme Glisse return -EFAULT; 989a3e0d41cSJérôme Glisse 99063d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 9911c2308f0SJason Gunthorpe if (huge_page_shift(hstate_vma(vma)) != 9921c2308f0SJason Gunthorpe range->page_shift && 99363d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 99463d5066fSJérôme Glisse return -EINVAL; 99563d5066fSJérôme Glisse } else { 99663d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 99763d5066fSJérôme Glisse return -EINVAL; 99863d5066fSJérôme Glisse } 99963d5066fSJérôme Glisse 100086586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 100186586a41SJérôme Glisse /* 1002a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 1003a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 1004a3e0d41cSJérôme Glisse * support architecture that allow write without read. 100586586a41SJérôme Glisse */ 1006a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 1007a3e0d41cSJérôme Glisse range->start, range->end); 100886586a41SJérôme Glisse return -EPERM; 100986586a41SJérôme Glisse } 101086586a41SJérôme Glisse 1011a3e0d41cSJérôme Glisse range->vma = vma; 1012992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1013a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 101474eee180SJérôme Glisse hmm_vma_walk.fault = false; 101574eee180SJérôme Glisse hmm_vma_walk.range = range; 101674eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1017a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 101874eee180SJérôme Glisse 1019da4c3c73SJérôme Glisse mm_walk.vma = vma; 1020da4c3c73SJérôme Glisse mm_walk.mm = vma->vm_mm; 1021da4c3c73SJérôme Glisse mm_walk.pte_entry = NULL; 1022da4c3c73SJérôme Glisse mm_walk.test_walk = NULL; 1023da4c3c73SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1024992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 1025da4c3c73SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 1026da4c3c73SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 102763d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 1028da4c3c73SJérôme Glisse 1029a3e0d41cSJérôme Glisse walk_page_range(start, end, &mm_walk); 1030a3e0d41cSJérôme Glisse start = end; 1031a3e0d41cSJérôme Glisse } while (start < range->end); 1032a3e0d41cSJérôme Glisse 103325f23a0cSJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1034da4c3c73SJérôme Glisse } 103525f23a0cSJérôme Glisse EXPORT_SYMBOL(hmm_range_snapshot); 1036da4c3c73SJérôme Glisse 1037da4c3c73SJérôme Glisse /* 103873231612SJérôme Glisse * hmm_range_fault() - try to fault some address in a virtual address range 103908232a45SJérôme Glisse * @range: range being faulted 104074eee180SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1041085ea250SRalph Campbell * Return: number of valid pages in range->pfns[] (from range start 104273231612SJérôme Glisse * address). This may be zero. If the return value is negative, 104373231612SJérôme Glisse * then one of the following values may be returned: 104473231612SJérôme Glisse * 104573231612SJérôme Glisse * -EINVAL invalid arguments or mm or virtual address are in an 104663d5066fSJérôme Glisse * invalid vma (for instance device file vma). 104773231612SJérôme Glisse * -ENOMEM: Out of memory. 104873231612SJérôme Glisse * -EPERM: Invalid permission (for instance asking for write and 104973231612SJérôme Glisse * range is read only). 105073231612SJérôme Glisse * -EAGAIN: If you need to retry and mmap_sem was drop. This can only 105173231612SJérôme Glisse * happens if block argument is false. 105273231612SJérôme Glisse * -EBUSY: If the the range is being invalidated and you should wait 105373231612SJérôme Glisse * for invalidation to finish. 105473231612SJérôme Glisse * -EFAULT: Invalid (ie either no valid vma or it is illegal to access 105573231612SJérôme Glisse * that range), number of valid pages in range->pfns[] (from 105673231612SJérôme Glisse * range start address). 105774eee180SJérôme Glisse * 105874eee180SJérôme Glisse * This is similar to a regular CPU page fault except that it will not trigger 105973231612SJérôme Glisse * any memory migration if the memory being faulted is not accessible by CPUs 106073231612SJérôme Glisse * and caller does not ask for migration. 106174eee180SJérôme Glisse * 1062ff05c0c6SJérôme Glisse * On error, for one virtual address in the range, the function will mark the 1063ff05c0c6SJérôme Glisse * corresponding HMM pfn entry with an error flag. 106474eee180SJérôme Glisse */ 106573231612SJérôme Glisse long hmm_range_fault(struct hmm_range *range, bool block) 106674eee180SJérôme Glisse { 106763d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 1068a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 106974eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 1070a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 1071a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 107274eee180SJérôme Glisse struct mm_walk mm_walk; 107374eee180SJérôme Glisse int ret; 107474eee180SJérôme Glisse 1075704f3f2cSJérôme Glisse /* Check if hmm_mm_destroy() was call. */ 1076a3e0d41cSJérôme Glisse if (hmm->mm == NULL || hmm->dead) 1077a3e0d41cSJérôme Glisse return -EFAULT; 1078a3e0d41cSJérôme Glisse 1079a3e0d41cSJérôme Glisse do { 1080a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 1081a3e0d41cSJérôme Glisse if (!range->valid) { 1082a3e0d41cSJérôme Glisse up_read(&hmm->mm->mmap_sem); 1083a3e0d41cSJérôme Glisse return -EAGAIN; 1084704f3f2cSJérôme Glisse } 108574eee180SJérôme Glisse 1086a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 108763d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 1088a3e0d41cSJérôme Glisse return -EFAULT; 1089a3e0d41cSJérôme Glisse 109063d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 109163d5066fSJérôme Glisse if (huge_page_shift(hstate_vma(vma)) != 109263d5066fSJérôme Glisse range->page_shift && 109363d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 109463d5066fSJérôme Glisse return -EINVAL; 109563d5066fSJérôme Glisse } else { 109663d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 109763d5066fSJérôme Glisse return -EINVAL; 109863d5066fSJérôme Glisse } 109963d5066fSJérôme Glisse 110086586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 110186586a41SJérôme Glisse /* 1102a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 1103a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 1104a3e0d41cSJérôme Glisse * support architecture that allow write without read. 110586586a41SJérôme Glisse */ 1106a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 1107a3e0d41cSJérôme Glisse range->start, range->end); 110886586a41SJérôme Glisse return -EPERM; 110986586a41SJérôme Glisse } 111074eee180SJérôme Glisse 1111a3e0d41cSJérôme Glisse range->vma = vma; 1112992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1113a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 111474eee180SJérôme Glisse hmm_vma_walk.fault = true; 111574eee180SJérôme Glisse hmm_vma_walk.block = block; 111674eee180SJérôme Glisse hmm_vma_walk.range = range; 111774eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1118a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 111974eee180SJérôme Glisse 112074eee180SJérôme Glisse mm_walk.vma = vma; 112174eee180SJérôme Glisse mm_walk.mm = vma->vm_mm; 112274eee180SJérôme Glisse mm_walk.pte_entry = NULL; 112374eee180SJérôme Glisse mm_walk.test_walk = NULL; 112474eee180SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1125992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 112674eee180SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 112774eee180SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 112863d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 112974eee180SJérôme Glisse 113074eee180SJérôme Glisse do { 1131a3e0d41cSJérôme Glisse ret = walk_page_range(start, end, &mm_walk); 113274eee180SJérôme Glisse start = hmm_vma_walk.last; 1133a3e0d41cSJérôme Glisse 113473231612SJérôme Glisse /* Keep trying while the range is valid. */ 113573231612SJérôme Glisse } while (ret == -EBUSY && range->valid); 113674eee180SJérôme Glisse 113774eee180SJérôme Glisse if (ret) { 113874eee180SJérôme Glisse unsigned long i; 113974eee180SJérôme Glisse 114074eee180SJérôme Glisse i = (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1141a3e0d41cSJérôme Glisse hmm_pfns_clear(range, &range->pfns[i], 1142a3e0d41cSJérôme Glisse hmm_vma_walk.last, range->end); 114373231612SJérôme Glisse return ret; 114474eee180SJérôme Glisse } 1145a3e0d41cSJérôme Glisse start = end; 1146a3e0d41cSJérôme Glisse 1147a3e0d41cSJérôme Glisse } while (start < range->end); 1148704f3f2cSJérôme Glisse 114973231612SJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 115074eee180SJérôme Glisse } 115173231612SJérôme Glisse EXPORT_SYMBOL(hmm_range_fault); 115255c0ece8SJérôme Glisse 115355c0ece8SJérôme Glisse /** 115455c0ece8SJérôme Glisse * hmm_range_dma_map() - hmm_range_fault() and dma map page all in one. 115555c0ece8SJérôme Glisse * @range: range being faulted 115655c0ece8SJérôme Glisse * @device: device against to dma map page to 115755c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 115855c0ece8SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1159085ea250SRalph Campbell * Return: number of pages mapped on success, -EAGAIN if mmap_sem have been 116055c0ece8SJérôme Glisse * drop and you need to try again, some other error value otherwise 116155c0ece8SJérôme Glisse * 116255c0ece8SJérôme Glisse * Note same usage pattern as hmm_range_fault(). 116355c0ece8SJérôme Glisse */ 116455c0ece8SJérôme Glisse long hmm_range_dma_map(struct hmm_range *range, 116555c0ece8SJérôme Glisse struct device *device, 116655c0ece8SJérôme Glisse dma_addr_t *daddrs, 116755c0ece8SJérôme Glisse bool block) 116855c0ece8SJérôme Glisse { 116955c0ece8SJérôme Glisse unsigned long i, npages, mapped; 117055c0ece8SJérôme Glisse long ret; 117155c0ece8SJérôme Glisse 117255c0ece8SJérôme Glisse ret = hmm_range_fault(range, block); 117355c0ece8SJérôme Glisse if (ret <= 0) 117455c0ece8SJérôme Glisse return ret ? ret : -EBUSY; 117555c0ece8SJérôme Glisse 117655c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 117755c0ece8SJérôme Glisse for (i = 0, mapped = 0; i < npages; ++i) { 117855c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 117955c0ece8SJérôme Glisse struct page *page; 118055c0ece8SJérôme Glisse 118155c0ece8SJérôme Glisse /* 118255c0ece8SJérôme Glisse * FIXME need to update DMA API to provide invalid DMA address 118355c0ece8SJérôme Glisse * value instead of a function to test dma address value. This 118455c0ece8SJérôme Glisse * would remove lot of dumb code duplicated accross many arch. 118555c0ece8SJérôme Glisse * 118655c0ece8SJérôme Glisse * For now setting it to 0 here is good enough as the pfns[] 118755c0ece8SJérôme Glisse * value is what is use to check what is valid and what isn't. 118855c0ece8SJérôme Glisse */ 118955c0ece8SJérôme Glisse daddrs[i] = 0; 119055c0ece8SJérôme Glisse 1191391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 119255c0ece8SJérôme Glisse if (page == NULL) 119355c0ece8SJérôme Glisse continue; 119455c0ece8SJérôme Glisse 119555c0ece8SJérôme Glisse /* Check if range is being invalidated */ 119655c0ece8SJérôme Glisse if (!range->valid) { 119755c0ece8SJérôme Glisse ret = -EBUSY; 119855c0ece8SJérôme Glisse goto unmap; 119955c0ece8SJérôme Glisse } 120055c0ece8SJérôme Glisse 120155c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 120255c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) 120355c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 120455c0ece8SJérôme Glisse 120555c0ece8SJérôme Glisse daddrs[i] = dma_map_page(device, page, 0, PAGE_SIZE, dir); 120655c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) { 120755c0ece8SJérôme Glisse ret = -EFAULT; 120855c0ece8SJérôme Glisse goto unmap; 120955c0ece8SJérôme Glisse } 121055c0ece8SJérôme Glisse 121155c0ece8SJérôme Glisse mapped++; 121255c0ece8SJérôme Glisse } 121355c0ece8SJérôme Glisse 121455c0ece8SJérôme Glisse return mapped; 121555c0ece8SJérôme Glisse 121655c0ece8SJérôme Glisse unmap: 121755c0ece8SJérôme Glisse for (npages = i, i = 0; (i < npages) && mapped; ++i) { 121855c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 121955c0ece8SJérôme Glisse struct page *page; 122055c0ece8SJérôme Glisse 1221391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 122255c0ece8SJérôme Glisse if (page == NULL) 122355c0ece8SJérôme Glisse continue; 122455c0ece8SJérôme Glisse 122555c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) 122655c0ece8SJérôme Glisse continue; 122755c0ece8SJérôme Glisse 122855c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 122955c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) 123055c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 123155c0ece8SJérôme Glisse 123255c0ece8SJérôme Glisse dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 123355c0ece8SJérôme Glisse mapped--; 123455c0ece8SJérôme Glisse } 123555c0ece8SJérôme Glisse 123655c0ece8SJérôme Glisse return ret; 123755c0ece8SJérôme Glisse } 123855c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_map); 123955c0ece8SJérôme Glisse 124055c0ece8SJérôme Glisse /** 124155c0ece8SJérôme Glisse * hmm_range_dma_unmap() - unmap range of that was map with hmm_range_dma_map() 124255c0ece8SJérôme Glisse * @range: range being unmapped 124355c0ece8SJérôme Glisse * @vma: the vma against which the range (optional) 124455c0ece8SJérôme Glisse * @device: device against which dma map was done 124555c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 124655c0ece8SJérôme Glisse * @dirty: dirty page if it had the write flag set 1247085ea250SRalph Campbell * Return: number of page unmapped on success, -EINVAL otherwise 124855c0ece8SJérôme Glisse * 124955c0ece8SJérôme Glisse * Note that caller MUST abide by mmu notifier or use HMM mirror and abide 125055c0ece8SJérôme Glisse * to the sync_cpu_device_pagetables() callback so that it is safe here to 125155c0ece8SJérôme Glisse * call set_page_dirty(). Caller must also take appropriate locks to avoid 125255c0ece8SJérôme Glisse * concurrent mmu notifier or sync_cpu_device_pagetables() to make progress. 125355c0ece8SJérôme Glisse */ 125455c0ece8SJérôme Glisse long hmm_range_dma_unmap(struct hmm_range *range, 125555c0ece8SJérôme Glisse struct vm_area_struct *vma, 125655c0ece8SJérôme Glisse struct device *device, 125755c0ece8SJérôme Glisse dma_addr_t *daddrs, 125855c0ece8SJérôme Glisse bool dirty) 125955c0ece8SJérôme Glisse { 126055c0ece8SJérôme Glisse unsigned long i, npages; 126155c0ece8SJérôme Glisse long cpages = 0; 126255c0ece8SJérôme Glisse 126355c0ece8SJérôme Glisse /* Sanity check. */ 126455c0ece8SJérôme Glisse if (range->end <= range->start) 126555c0ece8SJérôme Glisse return -EINVAL; 126655c0ece8SJérôme Glisse if (!daddrs) 126755c0ece8SJérôme Glisse return -EINVAL; 126855c0ece8SJérôme Glisse if (!range->pfns) 126955c0ece8SJérôme Glisse return -EINVAL; 127055c0ece8SJérôme Glisse 127155c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 127255c0ece8SJérôme Glisse for (i = 0; i < npages; ++i) { 127355c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 127455c0ece8SJérôme Glisse struct page *page; 127555c0ece8SJérôme Glisse 1276391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 127755c0ece8SJérôme Glisse if (page == NULL) 127855c0ece8SJérôme Glisse continue; 127955c0ece8SJérôme Glisse 128055c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 128155c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) { 128255c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 128355c0ece8SJérôme Glisse 128455c0ece8SJérôme Glisse /* 128555c0ece8SJérôme Glisse * See comments in function description on why it is 128655c0ece8SJérôme Glisse * safe here to call set_page_dirty() 128755c0ece8SJérôme Glisse */ 128855c0ece8SJérôme Glisse if (dirty) 128955c0ece8SJérôme Glisse set_page_dirty(page); 129055c0ece8SJérôme Glisse } 129155c0ece8SJérôme Glisse 129255c0ece8SJérôme Glisse /* Unmap and clear pfns/dma address */ 129355c0ece8SJérôme Glisse dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 129455c0ece8SJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 129555c0ece8SJérôme Glisse /* FIXME see comments in hmm_vma_dma_map() */ 129655c0ece8SJérôme Glisse daddrs[i] = 0; 129755c0ece8SJérôme Glisse cpages++; 129855c0ece8SJérôme Glisse } 129955c0ece8SJérôme Glisse 130055c0ece8SJérôme Glisse return cpages; 130155c0ece8SJérôme Glisse } 130255c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_unmap); 1303c0b12405SJérôme Glisse #endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */ 13044ef589dcSJérôme Glisse 13054ef589dcSJérôme Glisse 1306df6ad698SJérôme Glisse #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) 13074ef589dcSJérôme Glisse struct page *hmm_vma_alloc_locked_page(struct vm_area_struct *vma, 13084ef589dcSJérôme Glisse unsigned long addr) 13094ef589dcSJérôme Glisse { 13104ef589dcSJérôme Glisse struct page *page; 13114ef589dcSJérôme Glisse 13124ef589dcSJérôme Glisse page = alloc_page_vma(GFP_HIGHUSER, vma, addr); 13134ef589dcSJérôme Glisse if (!page) 13144ef589dcSJérôme Glisse return NULL; 13154ef589dcSJérôme Glisse lock_page(page); 13164ef589dcSJérôme Glisse return page; 13174ef589dcSJérôme Glisse } 13184ef589dcSJérôme Glisse EXPORT_SYMBOL(hmm_vma_alloc_locked_page); 13194ef589dcSJérôme Glisse 13204ef589dcSJérôme Glisse 13214ef589dcSJérôme Glisse static void hmm_devmem_ref_release(struct percpu_ref *ref) 13224ef589dcSJérôme Glisse { 13234ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13244ef589dcSJérôme Glisse 13254ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 13264ef589dcSJérôme Glisse complete(&devmem->completion); 13274ef589dcSJérôme Glisse } 13284ef589dcSJérôme Glisse 13294ef589dcSJérôme Glisse static void hmm_devmem_ref_exit(void *data) 13304ef589dcSJérôme Glisse { 13314ef589dcSJérôme Glisse struct percpu_ref *ref = data; 13324ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13334ef589dcSJérôme Glisse 13344ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 1335bbecd94eSDan Williams wait_for_completion(&devmem->completion); 13364ef589dcSJérôme Glisse percpu_ref_exit(ref); 13374ef589dcSJérôme Glisse } 13384ef589dcSJérôme Glisse 1339bbecd94eSDan Williams static void hmm_devmem_ref_kill(struct percpu_ref *ref) 13404ef589dcSJérôme Glisse { 13414ef589dcSJérôme Glisse percpu_ref_kill(ref); 13424ef589dcSJérôme Glisse } 13434ef589dcSJérôme Glisse 1344b57e622eSSouptick Joarder static vm_fault_t hmm_devmem_fault(struct vm_area_struct *vma, 13454ef589dcSJérôme Glisse unsigned long addr, 13464ef589dcSJérôme Glisse const struct page *page, 13474ef589dcSJérôme Glisse unsigned int flags, 13484ef589dcSJérôme Glisse pmd_t *pmdp) 13494ef589dcSJérôme Glisse { 13504ef589dcSJérôme Glisse struct hmm_devmem *devmem = page->pgmap->data; 13514ef589dcSJérôme Glisse 13524ef589dcSJérôme Glisse return devmem->ops->fault(devmem, vma, addr, page, flags, pmdp); 13534ef589dcSJérôme Glisse } 13544ef589dcSJérôme Glisse 13554ef589dcSJérôme Glisse static void hmm_devmem_free(struct page *page, void *data) 13564ef589dcSJérôme Glisse { 13574ef589dcSJérôme Glisse struct hmm_devmem *devmem = data; 13584ef589dcSJérôme Glisse 13592fa147bdSDan Williams page->mapping = NULL; 13602fa147bdSDan Williams 13614ef589dcSJérôme Glisse devmem->ops->free(devmem, page); 13624ef589dcSJérôme Glisse } 13634ef589dcSJérôme Glisse 13644ef589dcSJérôme Glisse /* 13654ef589dcSJérôme Glisse * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory 13664ef589dcSJérôme Glisse * 13674ef589dcSJérôme Glisse * @ops: memory event device driver callback (see struct hmm_devmem_ops) 13684ef589dcSJérôme Glisse * @device: device struct to bind the resource too 13694ef589dcSJérôme Glisse * @size: size in bytes of the device memory to add 1370085ea250SRalph Campbell * Return: pointer to new hmm_devmem struct ERR_PTR otherwise 13714ef589dcSJérôme Glisse * 13724ef589dcSJérôme Glisse * This function first finds an empty range of physical address big enough to 13734ef589dcSJérôme Glisse * contain the new resource, and then hotplugs it as ZONE_DEVICE memory, which 13744ef589dcSJérôme Glisse * in turn allocates struct pages. It does not do anything beyond that; all 13754ef589dcSJérôme Glisse * events affecting the memory will go through the various callbacks provided 13764ef589dcSJérôme Glisse * by hmm_devmem_ops struct. 13774ef589dcSJérôme Glisse * 13784ef589dcSJérôme Glisse * Device driver should call this function during device initialization and 13794ef589dcSJérôme Glisse * is then responsible of memory management. HMM only provides helpers. 13804ef589dcSJérôme Glisse */ 13814ef589dcSJérôme Glisse struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 13824ef589dcSJérôme Glisse struct device *device, 13834ef589dcSJérôme Glisse unsigned long size) 13844ef589dcSJérôme Glisse { 13854ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13864ef589dcSJérôme Glisse resource_size_t addr; 1387bbecd94eSDan Williams void *result; 13884ef589dcSJérôme Glisse int ret; 13894ef589dcSJérôme Glisse 1390e7638488SDan Williams dev_pagemap_get_ops(); 13914ef589dcSJérôme Glisse 139258ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 13934ef589dcSJérôme Glisse if (!devmem) 13944ef589dcSJérôme Glisse return ERR_PTR(-ENOMEM); 13954ef589dcSJérôme Glisse 13964ef589dcSJérôme Glisse init_completion(&devmem->completion); 13974ef589dcSJérôme Glisse devmem->pfn_first = -1UL; 13984ef589dcSJérôme Glisse devmem->pfn_last = -1UL; 13994ef589dcSJérôme Glisse devmem->resource = NULL; 14004ef589dcSJérôme Glisse devmem->device = device; 14014ef589dcSJérôme Glisse devmem->ops = ops; 14024ef589dcSJérôme Glisse 14034ef589dcSJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 14044ef589dcSJérôme Glisse 0, GFP_KERNEL); 14054ef589dcSJérôme Glisse if (ret) 140658ef15b7SDan Williams return ERR_PTR(ret); 14074ef589dcSJérôme Glisse 140858ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, &devmem->ref); 14094ef589dcSJérôme Glisse if (ret) 141058ef15b7SDan Williams return ERR_PTR(ret); 14114ef589dcSJérôme Glisse 14124ef589dcSJérôme Glisse size = ALIGN(size, PA_SECTION_SIZE); 14134ef589dcSJérôme Glisse addr = min((unsigned long)iomem_resource.end, 14144ef589dcSJérôme Glisse (1UL << MAX_PHYSMEM_BITS) - 1); 14154ef589dcSJérôme Glisse addr = addr - size + 1UL; 14164ef589dcSJérôme Glisse 14174ef589dcSJérôme Glisse /* 14184ef589dcSJérôme Glisse * FIXME add a new helper to quickly walk resource tree and find free 14194ef589dcSJérôme Glisse * range 14204ef589dcSJérôme Glisse * 14214ef589dcSJérôme Glisse * FIXME what about ioport_resource resource ? 14224ef589dcSJérôme Glisse */ 14234ef589dcSJérôme Glisse for (; addr > size && addr >= iomem_resource.start; addr -= size) { 14244ef589dcSJérôme Glisse ret = region_intersects(addr, size, 0, IORES_DESC_NONE); 14254ef589dcSJérôme Glisse if (ret != REGION_DISJOINT) 14264ef589dcSJérôme Glisse continue; 14274ef589dcSJérôme Glisse 14284ef589dcSJérôme Glisse devmem->resource = devm_request_mem_region(device, addr, size, 14294ef589dcSJérôme Glisse dev_name(device)); 143058ef15b7SDan Williams if (!devmem->resource) 143158ef15b7SDan Williams return ERR_PTR(-ENOMEM); 14324ef589dcSJérôme Glisse break; 14334ef589dcSJérôme Glisse } 143458ef15b7SDan Williams if (!devmem->resource) 143558ef15b7SDan Williams return ERR_PTR(-ERANGE); 14364ef589dcSJérôme Glisse 14374ef589dcSJérôme Glisse devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; 14384ef589dcSJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 14394ef589dcSJérôme Glisse devmem->pfn_last = devmem->pfn_first + 14404ef589dcSJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1441063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 14424ef589dcSJérôme Glisse 1443bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; 1444bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1445bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1446bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1447bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1448bbecd94eSDan Williams devmem->pagemap.data = devmem; 1449bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 145058ef15b7SDan Williams 1451bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1452bbecd94eSDan Williams if (IS_ERR(result)) 1453bbecd94eSDan Williams return result; 14544ef589dcSJérôme Glisse return devmem; 14554ef589dcSJérôme Glisse } 145602917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add); 14574ef589dcSJérôme Glisse 1458d3df0a42SJérôme Glisse struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, 1459d3df0a42SJérôme Glisse struct device *device, 1460d3df0a42SJérôme Glisse struct resource *res) 1461d3df0a42SJérôme Glisse { 1462d3df0a42SJérôme Glisse struct hmm_devmem *devmem; 1463bbecd94eSDan Williams void *result; 1464d3df0a42SJérôme Glisse int ret; 1465d3df0a42SJérôme Glisse 1466d3df0a42SJérôme Glisse if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) 1467d3df0a42SJérôme Glisse return ERR_PTR(-EINVAL); 1468d3df0a42SJérôme Glisse 1469e7638488SDan Williams dev_pagemap_get_ops(); 1470d3df0a42SJérôme Glisse 147158ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 1472d3df0a42SJérôme Glisse if (!devmem) 1473d3df0a42SJérôme Glisse return ERR_PTR(-ENOMEM); 1474d3df0a42SJérôme Glisse 1475d3df0a42SJérôme Glisse init_completion(&devmem->completion); 1476d3df0a42SJérôme Glisse devmem->pfn_first = -1UL; 1477d3df0a42SJérôme Glisse devmem->pfn_last = -1UL; 1478d3df0a42SJérôme Glisse devmem->resource = res; 1479d3df0a42SJérôme Glisse devmem->device = device; 1480d3df0a42SJérôme Glisse devmem->ops = ops; 1481d3df0a42SJérôme Glisse 1482d3df0a42SJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 1483d3df0a42SJérôme Glisse 0, GFP_KERNEL); 1484d3df0a42SJérôme Glisse if (ret) 148558ef15b7SDan Williams return ERR_PTR(ret); 1486d3df0a42SJérôme Glisse 148758ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, 148858ef15b7SDan Williams &devmem->ref); 1489d3df0a42SJérôme Glisse if (ret) 149058ef15b7SDan Williams return ERR_PTR(ret); 1491d3df0a42SJérôme Glisse 1492d3df0a42SJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 1493d3df0a42SJérôme Glisse devmem->pfn_last = devmem->pfn_first + 1494d3df0a42SJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1495063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 1496d3df0a42SJérôme Glisse 1497bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PUBLIC; 1498bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1499bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1500bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1501bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1502bbecd94eSDan Williams devmem->pagemap.data = devmem; 1503bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 150458ef15b7SDan Williams 1505bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1506bbecd94eSDan Williams if (IS_ERR(result)) 1507bbecd94eSDan Williams return result; 1508d3df0a42SJérôme Glisse return devmem; 1509d3df0a42SJérôme Glisse } 151002917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add_resource); 1511d3df0a42SJérôme Glisse 15124ef589dcSJérôme Glisse /* 1513858b54daSJérôme Glisse * A device driver that wants to handle multiple devices memory through a 1514858b54daSJérôme Glisse * single fake device can use hmm_device to do so. This is purely a helper 1515858b54daSJérôme Glisse * and it is not needed to make use of any HMM functionality. 1516858b54daSJérôme Glisse */ 1517858b54daSJérôme Glisse #define HMM_DEVICE_MAX 256 1518858b54daSJérôme Glisse 1519858b54daSJérôme Glisse static DECLARE_BITMAP(hmm_device_mask, HMM_DEVICE_MAX); 1520858b54daSJérôme Glisse static DEFINE_SPINLOCK(hmm_device_lock); 1521858b54daSJérôme Glisse static struct class *hmm_device_class; 1522858b54daSJérôme Glisse static dev_t hmm_device_devt; 1523858b54daSJérôme Glisse 1524858b54daSJérôme Glisse static void hmm_device_release(struct device *device) 1525858b54daSJérôme Glisse { 1526858b54daSJérôme Glisse struct hmm_device *hmm_device; 1527858b54daSJérôme Glisse 1528858b54daSJérôme Glisse hmm_device = container_of(device, struct hmm_device, device); 1529858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1530858b54daSJérôme Glisse clear_bit(hmm_device->minor, hmm_device_mask); 1531858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1532858b54daSJérôme Glisse 1533858b54daSJérôme Glisse kfree(hmm_device); 1534858b54daSJérôme Glisse } 1535858b54daSJérôme Glisse 1536858b54daSJérôme Glisse struct hmm_device *hmm_device_new(void *drvdata) 1537858b54daSJérôme Glisse { 1538858b54daSJérôme Glisse struct hmm_device *hmm_device; 1539858b54daSJérôme Glisse 1540858b54daSJérôme Glisse hmm_device = kzalloc(sizeof(*hmm_device), GFP_KERNEL); 1541858b54daSJérôme Glisse if (!hmm_device) 1542858b54daSJérôme Glisse return ERR_PTR(-ENOMEM); 1543858b54daSJérôme Glisse 1544858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1545858b54daSJérôme Glisse hmm_device->minor = find_first_zero_bit(hmm_device_mask, HMM_DEVICE_MAX); 1546858b54daSJérôme Glisse if (hmm_device->minor >= HMM_DEVICE_MAX) { 1547858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1548858b54daSJérôme Glisse kfree(hmm_device); 1549858b54daSJérôme Glisse return ERR_PTR(-EBUSY); 1550858b54daSJérôme Glisse } 1551858b54daSJérôme Glisse set_bit(hmm_device->minor, hmm_device_mask); 1552858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1553858b54daSJérôme Glisse 1554858b54daSJérôme Glisse dev_set_name(&hmm_device->device, "hmm_device%d", hmm_device->minor); 1555858b54daSJérôme Glisse hmm_device->device.devt = MKDEV(MAJOR(hmm_device_devt), 1556858b54daSJérôme Glisse hmm_device->minor); 1557858b54daSJérôme Glisse hmm_device->device.release = hmm_device_release; 1558858b54daSJérôme Glisse dev_set_drvdata(&hmm_device->device, drvdata); 1559858b54daSJérôme Glisse hmm_device->device.class = hmm_device_class; 1560858b54daSJérôme Glisse device_initialize(&hmm_device->device); 1561858b54daSJérôme Glisse 1562858b54daSJérôme Glisse return hmm_device; 1563858b54daSJérôme Glisse } 1564858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_new); 1565858b54daSJérôme Glisse 1566858b54daSJérôme Glisse void hmm_device_put(struct hmm_device *hmm_device) 1567858b54daSJérôme Glisse { 1568858b54daSJérôme Glisse put_device(&hmm_device->device); 1569858b54daSJérôme Glisse } 1570858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_put); 1571858b54daSJérôme Glisse 1572858b54daSJérôme Glisse static int __init hmm_init(void) 1573858b54daSJérôme Glisse { 1574858b54daSJérôme Glisse int ret; 1575858b54daSJérôme Glisse 1576858b54daSJérôme Glisse ret = alloc_chrdev_region(&hmm_device_devt, 0, 1577858b54daSJérôme Glisse HMM_DEVICE_MAX, 1578858b54daSJérôme Glisse "hmm_device"); 1579858b54daSJérôme Glisse if (ret) 1580858b54daSJérôme Glisse return ret; 1581858b54daSJérôme Glisse 1582858b54daSJérôme Glisse hmm_device_class = class_create(THIS_MODULE, "hmm_device"); 1583858b54daSJérôme Glisse if (IS_ERR(hmm_device_class)) { 1584858b54daSJérôme Glisse unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX); 1585858b54daSJérôme Glisse return PTR_ERR(hmm_device_class); 1586858b54daSJérôme Glisse } 1587858b54daSJérôme Glisse return 0; 1588858b54daSJérôme Glisse } 1589858b54daSJérôme Glisse 1590858b54daSJérôme Glisse device_initcall(hmm_init); 1591df6ad698SJérôme Glisse #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ 1592