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; 70c0b12405SJérôme Glisse hmm->mm = mm; 71c0b12405SJérôme Glisse 7286a2d598SRalph Campbell hmm->mmu_notifier.ops = &hmm_mmu_notifier_ops; 738a9320b7SJason Gunthorpe if (__mmu_notifier_register(&hmm->mmu_notifier, mm)) { 7486a2d598SRalph Campbell kfree(hmm); 7586a2d598SRalph Campbell return NULL; 76133ff0eaSJérôme Glisse } 77133ff0eaSJérôme Glisse 788a9320b7SJason Gunthorpe mmgrab(hmm->mm); 798a9320b7SJason Gunthorpe 808a9320b7SJason Gunthorpe /* 818a9320b7SJason Gunthorpe * We hold the exclusive mmap_sem here so we know that mm->hmm is 828a9320b7SJason Gunthorpe * still NULL or 0 kref, and is safe to update. 838a9320b7SJason Gunthorpe */ 848a9320b7SJason Gunthorpe spin_lock(&mm->page_table_lock); 858a9320b7SJason Gunthorpe mm->hmm = hmm; 868a9320b7SJason Gunthorpe 878a9320b7SJason Gunthorpe out_unlock: 888a9320b7SJason Gunthorpe spin_unlock(&mm->page_table_lock); 898a9320b7SJason Gunthorpe return hmm; 908a9320b7SJason Gunthorpe } 918a9320b7SJason Gunthorpe 926d7c3cdeSJason Gunthorpe static void hmm_free_rcu(struct rcu_head *rcu) 936d7c3cdeSJason Gunthorpe { 948a9320b7SJason Gunthorpe struct hmm *hmm = container_of(rcu, struct hmm, rcu); 958a9320b7SJason Gunthorpe 968a9320b7SJason Gunthorpe mmdrop(hmm->mm); 978a9320b7SJason Gunthorpe kfree(hmm); 986d7c3cdeSJason Gunthorpe } 996d7c3cdeSJason Gunthorpe 100704f3f2cSJérôme Glisse static void hmm_free(struct kref *kref) 101704f3f2cSJérôme Glisse { 102704f3f2cSJérôme Glisse struct hmm *hmm = container_of(kref, struct hmm, kref); 103704f3f2cSJérôme Glisse 1048a9320b7SJason Gunthorpe spin_lock(&hmm->mm->page_table_lock); 1058a9320b7SJason Gunthorpe if (hmm->mm->hmm == hmm) 1068a9320b7SJason Gunthorpe hmm->mm->hmm = NULL; 1078a9320b7SJason Gunthorpe spin_unlock(&hmm->mm->page_table_lock); 108704f3f2cSJérôme Glisse 1098a9320b7SJason Gunthorpe mmu_notifier_unregister_no_release(&hmm->mmu_notifier, hmm->mm); 1106d7c3cdeSJason Gunthorpe mmu_notifier_call_srcu(&hmm->rcu, hmm_free_rcu); 111704f3f2cSJérôme Glisse } 112704f3f2cSJérôme Glisse 113704f3f2cSJérôme Glisse static inline void hmm_put(struct hmm *hmm) 114704f3f2cSJérôme Glisse { 115704f3f2cSJérôme Glisse kref_put(&hmm->kref, hmm_free); 116704f3f2cSJérôme Glisse } 117704f3f2cSJérôme Glisse 118a3e0d41cSJérôme Glisse static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) 119c0b12405SJérôme Glisse { 1206d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 121c0b12405SJérôme Glisse struct hmm_mirror *mirror; 122da4c3c73SJérôme Glisse 1236d7c3cdeSJason Gunthorpe /* Bail out if hmm is in the process of being freed */ 1246d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1256d7c3cdeSJason Gunthorpe return; 1266d7c3cdeSJason Gunthorpe 127*47f24598SJason Gunthorpe /* 128*47f24598SJason Gunthorpe * Since hmm_range_register() holds the mmget() lock hmm_release() is 129*47f24598SJason Gunthorpe * prevented as long as a range exists. 130*47f24598SJason Gunthorpe */ 131*47f24598SJason Gunthorpe WARN_ON(!list_empty_careful(&hmm->ranges)); 132e1401513SRalph Campbell 133e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 134e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, struct hmm_mirror, 135e1401513SRalph Campbell list); 136e1401513SRalph Campbell while (mirror) { 137e1401513SRalph Campbell list_del_init(&mirror->list); 138e1401513SRalph Campbell if (mirror->ops->release) { 139e1401513SRalph Campbell /* 140085ea250SRalph Campbell * Drop mirrors_sem so the release callback can wait 141085ea250SRalph Campbell * on any pending work that might itself trigger a 142085ea250SRalph Campbell * mmu_notifier callback and thus would deadlock with 143085ea250SRalph Campbell * us. 144e1401513SRalph Campbell */ 145e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 146e1401513SRalph Campbell mirror->ops->release(mirror); 147e1401513SRalph Campbell down_write(&hmm->mirrors_sem); 148e1401513SRalph Campbell } 149e1401513SRalph Campbell mirror = list_first_entry_or_null(&hmm->mirrors, 150e1401513SRalph Campbell struct hmm_mirror, list); 151e1401513SRalph Campbell } 152e1401513SRalph Campbell up_write(&hmm->mirrors_sem); 153704f3f2cSJérôme Glisse 154704f3f2cSJérôme Glisse hmm_put(hmm); 155e1401513SRalph Campbell } 156e1401513SRalph Campbell 15793065ac7SMichal Hocko static int hmm_invalidate_range_start(struct mmu_notifier *mn, 158a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 159c0b12405SJérôme Glisse { 1606d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 161a3e0d41cSJérôme Glisse struct hmm_mirror *mirror; 162ec131b2dSJérôme Glisse struct hmm_update update; 163a3e0d41cSJérôme Glisse struct hmm_range *range; 164a3e0d41cSJérôme Glisse int ret = 0; 165c0b12405SJérôme Glisse 1666d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 1676d7c3cdeSJason Gunthorpe return 0; 168c0b12405SJérôme Glisse 169a3e0d41cSJérôme Glisse update.start = nrange->start; 170a3e0d41cSJérôme Glisse update.end = nrange->end; 171ec131b2dSJérôme Glisse update.event = HMM_UPDATE_INVALIDATE; 172dfcd6660SJérôme Glisse update.blockable = mmu_notifier_range_blockable(nrange); 173a3e0d41cSJérôme Glisse 174dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 175a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 176a3e0d41cSJérôme Glisse else if (!mutex_trylock(&hmm->lock)) { 177a3e0d41cSJérôme Glisse ret = -EAGAIN; 178a3e0d41cSJérôme Glisse goto out; 179a3e0d41cSJérôme Glisse } 180a3e0d41cSJérôme Glisse hmm->notifiers++; 181a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 182a3e0d41cSJérôme Glisse if (update.end < range->start || update.start >= range->end) 183a3e0d41cSJérôme Glisse continue; 184a3e0d41cSJérôme Glisse 185a3e0d41cSJérôme Glisse range->valid = false; 186a3e0d41cSJérôme Glisse } 187a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 188a3e0d41cSJérôme Glisse 189dfcd6660SJérôme Glisse if (mmu_notifier_range_blockable(nrange)) 190a3e0d41cSJérôme Glisse down_read(&hmm->mirrors_sem); 191a3e0d41cSJérôme Glisse else if (!down_read_trylock(&hmm->mirrors_sem)) { 192a3e0d41cSJérôme Glisse ret = -EAGAIN; 193a3e0d41cSJérôme Glisse goto out; 194a3e0d41cSJérôme Glisse } 195a3e0d41cSJérôme Glisse list_for_each_entry(mirror, &hmm->mirrors, list) { 196a3e0d41cSJérôme Glisse int ret; 197a3e0d41cSJérôme Glisse 198a3e0d41cSJérôme Glisse ret = mirror->ops->sync_cpu_device_pagetables(mirror, &update); 199085ea250SRalph Campbell if (!update.blockable && ret == -EAGAIN) 200085ea250SRalph Campbell break; 201a3e0d41cSJérôme Glisse } 202a3e0d41cSJérôme Glisse up_read(&hmm->mirrors_sem); 203a3e0d41cSJérôme Glisse 204a3e0d41cSJérôme Glisse out: 205704f3f2cSJérôme Glisse hmm_put(hmm); 206704f3f2cSJérôme Glisse return ret; 207c0b12405SJérôme Glisse } 208c0b12405SJérôme Glisse 209c0b12405SJérôme Glisse static void hmm_invalidate_range_end(struct mmu_notifier *mn, 210a3e0d41cSJérôme Glisse const struct mmu_notifier_range *nrange) 211c0b12405SJérôme Glisse { 2126d7c3cdeSJason Gunthorpe struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); 213c0b12405SJérôme Glisse 2146d7c3cdeSJason Gunthorpe if (!kref_get_unless_zero(&hmm->kref)) 2156d7c3cdeSJason Gunthorpe return; 216c0b12405SJérôme Glisse 217a3e0d41cSJérôme Glisse mutex_lock(&hmm->lock); 218a3e0d41cSJérôme Glisse hmm->notifiers--; 219a3e0d41cSJérôme Glisse if (!hmm->notifiers) { 220a3e0d41cSJérôme Glisse struct hmm_range *range; 221a3e0d41cSJérôme Glisse 222a3e0d41cSJérôme Glisse list_for_each_entry(range, &hmm->ranges, list) { 223a3e0d41cSJérôme Glisse if (range->valid) 224a3e0d41cSJérôme Glisse continue; 225a3e0d41cSJérôme Glisse range->valid = true; 226a3e0d41cSJérôme Glisse } 227a3e0d41cSJérôme Glisse wake_up_all(&hmm->wq); 228a3e0d41cSJérôme Glisse } 229a3e0d41cSJérôme Glisse mutex_unlock(&hmm->lock); 230a3e0d41cSJérôme Glisse 231704f3f2cSJérôme Glisse hmm_put(hmm); 232c0b12405SJérôme Glisse } 233c0b12405SJérôme Glisse 234c0b12405SJérôme Glisse static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { 235e1401513SRalph Campbell .release = hmm_release, 236c0b12405SJérôme Glisse .invalidate_range_start = hmm_invalidate_range_start, 237c0b12405SJérôme Glisse .invalidate_range_end = hmm_invalidate_range_end, 238c0b12405SJérôme Glisse }; 239c0b12405SJérôme Glisse 240c0b12405SJérôme Glisse /* 241c0b12405SJérôme Glisse * hmm_mirror_register() - register a mirror against an mm 242c0b12405SJérôme Glisse * 243c0b12405SJérôme Glisse * @mirror: new mirror struct to register 244c0b12405SJérôme Glisse * @mm: mm to register against 245085ea250SRalph Campbell * Return: 0 on success, -ENOMEM if no memory, -EINVAL if invalid arguments 246c0b12405SJérôme Glisse * 247c0b12405SJérôme Glisse * To start mirroring a process address space, the device driver must register 248c0b12405SJérôme Glisse * an HMM mirror struct. 249c0b12405SJérôme Glisse * 250c0b12405SJérôme Glisse * THE mm->mmap_sem MUST BE HELD IN WRITE MODE ! 251c0b12405SJérôme Glisse */ 252c0b12405SJérôme Glisse int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm) 253c0b12405SJérôme Glisse { 254c0b12405SJérôme Glisse /* Sanity check */ 255c0b12405SJérôme Glisse if (!mm || !mirror || !mirror->ops) 256c0b12405SJérôme Glisse return -EINVAL; 257c0b12405SJérôme Glisse 258704f3f2cSJérôme Glisse mirror->hmm = hmm_get_or_create(mm); 259c0b12405SJérôme Glisse if (!mirror->hmm) 260c0b12405SJérôme Glisse return -ENOMEM; 261c0b12405SJérôme Glisse 262c0b12405SJérôme Glisse down_write(&mirror->hmm->mirrors_sem); 263c0b12405SJérôme Glisse list_add(&mirror->list, &mirror->hmm->mirrors); 264c0b12405SJérôme Glisse up_write(&mirror->hmm->mirrors_sem); 265c0b12405SJérôme Glisse 266c0b12405SJérôme Glisse return 0; 267c0b12405SJérôme Glisse } 268c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_register); 269c0b12405SJérôme Glisse 270c0b12405SJérôme Glisse /* 271c0b12405SJérôme Glisse * hmm_mirror_unregister() - unregister a mirror 272c0b12405SJérôme Glisse * 273085ea250SRalph Campbell * @mirror: mirror struct to unregister 274c0b12405SJérôme Glisse * 275c0b12405SJérôme Glisse * Stop mirroring a process address space, and cleanup. 276c0b12405SJérôme Glisse */ 277c0b12405SJérôme Glisse void hmm_mirror_unregister(struct hmm_mirror *mirror) 278c0b12405SJérôme Glisse { 279704f3f2cSJérôme Glisse struct hmm *hmm = READ_ONCE(mirror->hmm); 280c0b12405SJérôme Glisse 281704f3f2cSJérôme Glisse if (hmm == NULL) 282c01cbba2SJérôme Glisse return; 283c01cbba2SJérôme Glisse 284c0b12405SJérôme Glisse down_write(&hmm->mirrors_sem); 285e1401513SRalph Campbell list_del_init(&mirror->list); 286704f3f2cSJérôme Glisse /* To protect us against double unregister ... */ 287c01cbba2SJérôme Glisse mirror->hmm = NULL; 288c0b12405SJérôme Glisse up_write(&hmm->mirrors_sem); 289c01cbba2SJérôme Glisse 290704f3f2cSJérôme Glisse hmm_put(hmm); 291c0b12405SJérôme Glisse } 292c0b12405SJérôme Glisse EXPORT_SYMBOL(hmm_mirror_unregister); 293da4c3c73SJérôme Glisse 29474eee180SJérôme Glisse struct hmm_vma_walk { 29574eee180SJérôme Glisse struct hmm_range *range; 296992de9a8SJérôme Glisse struct dev_pagemap *pgmap; 29774eee180SJérôme Glisse unsigned long last; 29874eee180SJérôme Glisse bool fault; 29974eee180SJérôme Glisse bool block; 30074eee180SJérôme Glisse }; 30174eee180SJérôme Glisse 3022aee09d8SJérôme Glisse static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr, 3032aee09d8SJérôme Glisse bool write_fault, uint64_t *pfn) 30474eee180SJérôme Glisse { 3059b1ae605SKuehling, Felix unsigned int flags = FAULT_FLAG_REMOTE; 30674eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 307f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 30874eee180SJérôme Glisse struct vm_area_struct *vma = walk->vma; 30950a7ca3cSSouptick Joarder vm_fault_t ret; 31074eee180SJérôme Glisse 31174eee180SJérôme Glisse flags |= hmm_vma_walk->block ? 0 : FAULT_FLAG_ALLOW_RETRY; 3122aee09d8SJérôme Glisse flags |= write_fault ? FAULT_FLAG_WRITE : 0; 31350a7ca3cSSouptick Joarder ret = handle_mm_fault(vma, addr, flags); 31450a7ca3cSSouptick Joarder if (ret & VM_FAULT_RETRY) 31573231612SJérôme Glisse return -EAGAIN; 31650a7ca3cSSouptick Joarder if (ret & VM_FAULT_ERROR) { 317f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 31874eee180SJérôme Glisse return -EFAULT; 31974eee180SJérôme Glisse } 32074eee180SJérôme Glisse 32173231612SJérôme Glisse return -EBUSY; 32274eee180SJérôme Glisse } 32374eee180SJérôme Glisse 324da4c3c73SJérôme Glisse static int hmm_pfns_bad(unsigned long addr, 325da4c3c73SJérôme Glisse unsigned long end, 326da4c3c73SJérôme Glisse struct mm_walk *walk) 327da4c3c73SJérôme Glisse { 328c719547fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 329c719547fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 330ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 331da4c3c73SJérôme Glisse unsigned long i; 332da4c3c73SJérôme Glisse 333da4c3c73SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 334da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, i++) 335f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_ERROR]; 336da4c3c73SJérôme Glisse 337da4c3c73SJérôme Glisse return 0; 338da4c3c73SJérôme Glisse } 339da4c3c73SJérôme Glisse 3405504ed29SJérôme Glisse /* 3415504ed29SJérôme Glisse * hmm_vma_walk_hole() - handle a range lacking valid pmd or pte(s) 3425504ed29SJérôme Glisse * @start: range virtual start address (inclusive) 3435504ed29SJérôme Glisse * @end: range virtual end address (exclusive) 3442aee09d8SJérôme Glisse * @fault: should we fault or not ? 3452aee09d8SJérôme Glisse * @write_fault: write fault ? 3465504ed29SJérôme Glisse * @walk: mm_walk structure 347085ea250SRalph Campbell * Return: 0 on success, -EBUSY after page fault, or page fault error 3485504ed29SJérôme Glisse * 3495504ed29SJérôme Glisse * This function will be called whenever pmd_none() or pte_none() returns true, 3505504ed29SJérôme Glisse * or whenever there is no page directory covering the virtual address range. 3515504ed29SJérôme Glisse */ 3522aee09d8SJérôme Glisse static int hmm_vma_walk_hole_(unsigned long addr, unsigned long end, 3532aee09d8SJérôme Glisse bool fault, bool write_fault, 354da4c3c73SJérôme Glisse struct mm_walk *walk) 355da4c3c73SJérôme Glisse { 35674eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 35774eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 358ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 35963d5066fSJérôme Glisse unsigned long i, page_size; 360da4c3c73SJérôme Glisse 36174eee180SJérôme Glisse hmm_vma_walk->last = addr; 36263d5066fSJérôme Glisse page_size = hmm_range_page_size(range); 36363d5066fSJérôme Glisse i = (addr - range->start) >> range->page_shift; 36463d5066fSJérôme Glisse 36563d5066fSJérôme Glisse for (; addr < end; addr += page_size, i++) { 366f88a1e90SJérôme Glisse pfns[i] = range->values[HMM_PFN_NONE]; 3672aee09d8SJérôme Glisse if (fault || write_fault) { 36874eee180SJérôme Glisse int ret; 369da4c3c73SJérôme Glisse 3702aee09d8SJérôme Glisse ret = hmm_vma_do_fault(walk, addr, write_fault, 3712aee09d8SJérôme Glisse &pfns[i]); 37273231612SJérôme Glisse if (ret != -EBUSY) 37374eee180SJérôme Glisse return ret; 37474eee180SJérôme Glisse } 37574eee180SJérôme Glisse } 37674eee180SJérôme Glisse 37773231612SJérôme Glisse return (fault || write_fault) ? -EBUSY : 0; 3782aee09d8SJérôme Glisse } 3792aee09d8SJérôme Glisse 3802aee09d8SJérôme Glisse static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 3812aee09d8SJérôme Glisse uint64_t pfns, uint64_t cpu_flags, 3822aee09d8SJérôme Glisse bool *fault, bool *write_fault) 3832aee09d8SJérôme Glisse { 384f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 385f88a1e90SJérôme Glisse 3862aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) 3872aee09d8SJérôme Glisse return; 3882aee09d8SJérôme Glisse 389023a019aSJérôme Glisse /* 390023a019aSJérôme Glisse * So we not only consider the individual per page request we also 391023a019aSJérôme Glisse * consider the default flags requested for the range. The API can 392023a019aSJérôme Glisse * be use in 2 fashions. The first one where the HMM user coalesce 393023a019aSJérôme Glisse * multiple page fault into one request and set flags per pfns for 394023a019aSJérôme Glisse * of those faults. The second one where the HMM user want to pre- 395023a019aSJérôme Glisse * fault a range with specific flags. For the latter one it is a 396023a019aSJérôme Glisse * waste to have the user pre-fill the pfn arrays with a default 397023a019aSJérôme Glisse * flags value. 398023a019aSJérôme Glisse */ 399023a019aSJérôme Glisse pfns = (pfns & range->pfn_flags_mask) | range->default_flags; 400023a019aSJérôme Glisse 4012aee09d8SJérôme Glisse /* We aren't ask to do anything ... */ 402f88a1e90SJérôme Glisse if (!(pfns & range->flags[HMM_PFN_VALID])) 4032aee09d8SJérôme Glisse return; 404f88a1e90SJérôme Glisse /* If this is device memory than only fault if explicitly requested */ 405f88a1e90SJérôme Glisse if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) { 406f88a1e90SJérôme Glisse /* Do we fault on device memory ? */ 407f88a1e90SJérôme Glisse if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) { 408f88a1e90SJérôme Glisse *write_fault = pfns & range->flags[HMM_PFN_WRITE]; 409f88a1e90SJérôme Glisse *fault = true; 410f88a1e90SJérôme Glisse } 4112aee09d8SJérôme Glisse return; 4122aee09d8SJérôme Glisse } 413f88a1e90SJérôme Glisse 414f88a1e90SJérôme Glisse /* If CPU page table is not valid then we need to fault */ 415f88a1e90SJérôme Glisse *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]); 416f88a1e90SJérôme Glisse /* Need to write fault ? */ 417f88a1e90SJérôme Glisse if ((pfns & range->flags[HMM_PFN_WRITE]) && 418f88a1e90SJérôme Glisse !(cpu_flags & range->flags[HMM_PFN_WRITE])) { 419f88a1e90SJérôme Glisse *write_fault = true; 4202aee09d8SJérôme Glisse *fault = true; 4212aee09d8SJérôme Glisse } 4222aee09d8SJérôme Glisse } 4232aee09d8SJérôme Glisse 4242aee09d8SJérôme Glisse static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk, 4252aee09d8SJérôme Glisse const uint64_t *pfns, unsigned long npages, 4262aee09d8SJérôme Glisse uint64_t cpu_flags, bool *fault, 4272aee09d8SJérôme Glisse bool *write_fault) 4282aee09d8SJérôme Glisse { 4292aee09d8SJérôme Glisse unsigned long i; 4302aee09d8SJérôme Glisse 4312aee09d8SJérôme Glisse if (!hmm_vma_walk->fault) { 4322aee09d8SJérôme Glisse *fault = *write_fault = false; 4332aee09d8SJérôme Glisse return; 4342aee09d8SJérôme Glisse } 4352aee09d8SJérôme Glisse 436a3e0d41cSJérôme Glisse *fault = *write_fault = false; 4372aee09d8SJérôme Glisse for (i = 0; i < npages; ++i) { 4382aee09d8SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags, 4392aee09d8SJérôme Glisse fault, write_fault); 440a3e0d41cSJérôme Glisse if ((*write_fault)) 4412aee09d8SJérôme Glisse return; 4422aee09d8SJérôme Glisse } 4432aee09d8SJérôme Glisse } 4442aee09d8SJérôme Glisse 4452aee09d8SJérôme Glisse static int hmm_vma_walk_hole(unsigned long addr, unsigned long end, 4462aee09d8SJérôme Glisse struct mm_walk *walk) 4472aee09d8SJérôme Glisse { 4482aee09d8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 4492aee09d8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 4502aee09d8SJérôme Glisse bool fault, write_fault; 4512aee09d8SJérôme Glisse unsigned long i, npages; 4522aee09d8SJérôme Glisse uint64_t *pfns; 4532aee09d8SJérôme Glisse 4542aee09d8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 4552aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 4562aee09d8SJérôme Glisse pfns = &range->pfns[i]; 4572aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 4582aee09d8SJérôme Glisse 0, &fault, &write_fault); 4592aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 4602aee09d8SJérôme Glisse } 4612aee09d8SJérôme Glisse 462f88a1e90SJérôme Glisse static inline uint64_t pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd) 4632aee09d8SJérôme Glisse { 4642aee09d8SJérôme Glisse if (pmd_protnone(pmd)) 4652aee09d8SJérôme Glisse return 0; 466f88a1e90SJérôme Glisse return pmd_write(pmd) ? range->flags[HMM_PFN_VALID] | 467f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 468f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 469da4c3c73SJérôme Glisse } 470da4c3c73SJérôme Glisse 471992de9a8SJérôme Glisse static inline uint64_t pud_to_hmm_pfn_flags(struct hmm_range *range, pud_t pud) 472992de9a8SJérôme Glisse { 473992de9a8SJérôme Glisse if (!pud_present(pud)) 474992de9a8SJérôme Glisse return 0; 475992de9a8SJérôme Glisse return pud_write(pud) ? range->flags[HMM_PFN_VALID] | 476992de9a8SJérôme Glisse range->flags[HMM_PFN_WRITE] : 477992de9a8SJérôme Glisse range->flags[HMM_PFN_VALID]; 478992de9a8SJérôme Glisse } 479992de9a8SJérôme Glisse 48053f5c3f4SJérôme Glisse static int hmm_vma_handle_pmd(struct mm_walk *walk, 48153f5c3f4SJérôme Glisse unsigned long addr, 48253f5c3f4SJérôme Glisse unsigned long end, 48353f5c3f4SJérôme Glisse uint64_t *pfns, 48453f5c3f4SJérôme Glisse pmd_t pmd) 48553f5c3f4SJérôme Glisse { 486992de9a8SJérôme Glisse #ifdef CONFIG_TRANSPARENT_HUGEPAGE 48753f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 488f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 4892aee09d8SJérôme Glisse unsigned long pfn, npages, i; 4902aee09d8SJérôme Glisse bool fault, write_fault; 491f88a1e90SJérôme Glisse uint64_t cpu_flags; 49253f5c3f4SJérôme Glisse 4932aee09d8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 494f88a1e90SJérôme Glisse cpu_flags = pmd_to_hmm_pfn_flags(range, pmd); 4952aee09d8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags, 4962aee09d8SJérôme Glisse &fault, &write_fault); 49753f5c3f4SJérôme Glisse 4982aee09d8SJérôme Glisse if (pmd_protnone(pmd) || fault || write_fault) 4992aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 50053f5c3f4SJérôme Glisse 50153f5c3f4SJérôme Glisse pfn = pmd_pfn(pmd) + pte_index(addr); 502992de9a8SJérôme Glisse for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { 503992de9a8SJérôme Glisse if (pmd_devmap(pmd)) { 504992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 505992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 506992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 507992de9a8SJérôme Glisse return -EBUSY; 508992de9a8SJérôme Glisse } 509391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; 510992de9a8SJérôme Glisse } 511992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 512992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 513992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 514992de9a8SJérôme Glisse } 51553f5c3f4SJérôme Glisse hmm_vma_walk->last = end; 51653f5c3f4SJérôme Glisse return 0; 517992de9a8SJérôme Glisse #else 518992de9a8SJérôme Glisse /* If THP is not enabled then we should never reach that code ! */ 519992de9a8SJérôme Glisse return -EINVAL; 520992de9a8SJérôme Glisse #endif 52153f5c3f4SJérôme Glisse } 52253f5c3f4SJérôme Glisse 523f88a1e90SJérôme Glisse static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte) 5242aee09d8SJérôme Glisse { 525789c2af8SPhilip Yang if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte)) 5262aee09d8SJérôme Glisse return 0; 527f88a1e90SJérôme Glisse return pte_write(pte) ? range->flags[HMM_PFN_VALID] | 528f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 529f88a1e90SJérôme Glisse range->flags[HMM_PFN_VALID]; 5302aee09d8SJérôme Glisse } 5312aee09d8SJérôme Glisse 53253f5c3f4SJérôme Glisse static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, 53353f5c3f4SJérôme Glisse unsigned long end, pmd_t *pmdp, pte_t *ptep, 53453f5c3f4SJérôme Glisse uint64_t *pfn) 53553f5c3f4SJérôme Glisse { 53653f5c3f4SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 537f88a1e90SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 53853f5c3f4SJérôme Glisse struct vm_area_struct *vma = walk->vma; 5392aee09d8SJérôme Glisse bool fault, write_fault; 5402aee09d8SJérôme Glisse uint64_t cpu_flags; 54153f5c3f4SJérôme Glisse pte_t pte = *ptep; 542f88a1e90SJérôme Glisse uint64_t orig_pfn = *pfn; 54353f5c3f4SJérôme Glisse 544f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_NONE]; 54573231612SJérôme Glisse fault = write_fault = false; 54653f5c3f4SJérôme Glisse 54753f5c3f4SJérôme Glisse if (pte_none(pte)) { 54873231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, 54973231612SJérôme Glisse &fault, &write_fault); 5502aee09d8SJérôme Glisse if (fault || write_fault) 55153f5c3f4SJérôme Glisse goto fault; 55253f5c3f4SJérôme Glisse return 0; 55353f5c3f4SJérôme Glisse } 55453f5c3f4SJérôme Glisse 55553f5c3f4SJérôme Glisse if (!pte_present(pte)) { 55653f5c3f4SJérôme Glisse swp_entry_t entry = pte_to_swp_entry(pte); 55753f5c3f4SJérôme Glisse 55853f5c3f4SJérôme Glisse if (!non_swap_entry(entry)) { 5592aee09d8SJérôme Glisse if (fault || write_fault) 56053f5c3f4SJérôme Glisse goto fault; 56153f5c3f4SJérôme Glisse return 0; 56253f5c3f4SJérôme Glisse } 56353f5c3f4SJérôme Glisse 56453f5c3f4SJérôme Glisse /* 56553f5c3f4SJérôme Glisse * This is a special swap entry, ignore migration, use 56653f5c3f4SJérôme Glisse * device and report anything else as error. 56753f5c3f4SJérôme Glisse */ 56853f5c3f4SJérôme Glisse if (is_device_private_entry(entry)) { 569f88a1e90SJérôme Glisse cpu_flags = range->flags[HMM_PFN_VALID] | 570f88a1e90SJérôme Glisse range->flags[HMM_PFN_DEVICE_PRIVATE]; 5712aee09d8SJérôme Glisse cpu_flags |= is_write_device_private_entry(entry) ? 572f88a1e90SJérôme Glisse range->flags[HMM_PFN_WRITE] : 0; 573f88a1e90SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 574f88a1e90SJérôme Glisse &fault, &write_fault); 575f88a1e90SJérôme Glisse if (fault || write_fault) 576f88a1e90SJérôme Glisse goto fault; 577391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, 578391aab11SJérôme Glisse swp_offset(entry)); 579f88a1e90SJérôme Glisse *pfn |= cpu_flags; 58053f5c3f4SJérôme Glisse return 0; 58153f5c3f4SJérôme Glisse } 58253f5c3f4SJérôme Glisse 58353f5c3f4SJérôme Glisse if (is_migration_entry(entry)) { 5842aee09d8SJérôme Glisse if (fault || write_fault) { 58553f5c3f4SJérôme Glisse pte_unmap(ptep); 58653f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 58753f5c3f4SJérôme Glisse migration_entry_wait(vma->vm_mm, 58853f5c3f4SJérôme Glisse pmdp, addr); 58973231612SJérôme Glisse return -EBUSY; 59053f5c3f4SJérôme Glisse } 59153f5c3f4SJérôme Glisse return 0; 59253f5c3f4SJérôme Glisse } 59353f5c3f4SJérôme Glisse 59453f5c3f4SJérôme Glisse /* Report error for everything else */ 595f88a1e90SJérôme Glisse *pfn = range->values[HMM_PFN_ERROR]; 59653f5c3f4SJérôme Glisse return -EFAULT; 59773231612SJérôme Glisse } else { 59873231612SJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, pte); 59973231612SJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 60073231612SJérôme Glisse &fault, &write_fault); 60153f5c3f4SJérôme Glisse } 60253f5c3f4SJérôme Glisse 6032aee09d8SJérôme Glisse if (fault || write_fault) 60453f5c3f4SJérôme Glisse goto fault; 60553f5c3f4SJérôme Glisse 606992de9a8SJérôme Glisse if (pte_devmap(pte)) { 607992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pte_pfn(pte), 608992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 609992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 610992de9a8SJérôme Glisse return -EBUSY; 611992de9a8SJérôme Glisse } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) { 612992de9a8SJérôme Glisse *pfn = range->values[HMM_PFN_SPECIAL]; 613992de9a8SJérôme Glisse return -EFAULT; 614992de9a8SJérôme Glisse } 615992de9a8SJérôme Glisse 616391aab11SJérôme Glisse *pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags; 61753f5c3f4SJérôme Glisse return 0; 61853f5c3f4SJérôme Glisse 61953f5c3f4SJérôme Glisse fault: 620992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 621992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 622992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 623992de9a8SJérôme Glisse } 62453f5c3f4SJérôme Glisse pte_unmap(ptep); 62553f5c3f4SJérôme Glisse /* Fault any virtual address we were asked to fault */ 6262aee09d8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 62753f5c3f4SJérôme Glisse } 62853f5c3f4SJérôme Glisse 629da4c3c73SJérôme Glisse static int hmm_vma_walk_pmd(pmd_t *pmdp, 630da4c3c73SJérôme Glisse unsigned long start, 631da4c3c73SJérôme Glisse unsigned long end, 632da4c3c73SJérôme Glisse struct mm_walk *walk) 633da4c3c73SJérôme Glisse { 63474eee180SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 63574eee180SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 636d08faca0SJérôme Glisse struct vm_area_struct *vma = walk->vma; 637ff05c0c6SJérôme Glisse uint64_t *pfns = range->pfns; 638da4c3c73SJérôme Glisse unsigned long addr = start, i; 639da4c3c73SJérôme Glisse pte_t *ptep; 640da4c3c73SJérôme Glisse pmd_t pmd; 641da4c3c73SJérôme Glisse 642d08faca0SJérôme Glisse 643d08faca0SJérôme Glisse again: 644d08faca0SJérôme Glisse pmd = READ_ONCE(*pmdp); 645d08faca0SJérôme Glisse if (pmd_none(pmd)) 646d08faca0SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 647d08faca0SJérôme Glisse 648d08faca0SJérôme Glisse if (pmd_huge(pmd) && (range->vma->vm_flags & VM_HUGETLB)) 649d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 650d08faca0SJérôme Glisse 651d08faca0SJérôme Glisse if (thp_migration_supported() && is_pmd_migration_entry(pmd)) { 652d08faca0SJérôme Glisse bool fault, write_fault; 653d08faca0SJérôme Glisse unsigned long npages; 654d08faca0SJérôme Glisse uint64_t *pfns; 655d08faca0SJérôme Glisse 656d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 657d08faca0SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 658d08faca0SJérôme Glisse pfns = &range->pfns[i]; 659d08faca0SJérôme Glisse 660d08faca0SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 661d08faca0SJérôme Glisse 0, &fault, &write_fault); 662d08faca0SJérôme Glisse if (fault || write_fault) { 663d08faca0SJérôme Glisse hmm_vma_walk->last = addr; 664d08faca0SJérôme Glisse pmd_migration_entry_wait(vma->vm_mm, pmdp); 66573231612SJérôme Glisse return -EBUSY; 666d08faca0SJérôme Glisse } 667d08faca0SJérôme Glisse return 0; 668d08faca0SJérôme Glisse } else if (!pmd_present(pmd)) 669d08faca0SJérôme Glisse return hmm_pfns_bad(start, end, walk); 670d08faca0SJérôme Glisse 671d08faca0SJérôme Glisse if (pmd_devmap(pmd) || pmd_trans_huge(pmd)) { 672da4c3c73SJérôme Glisse /* 673da4c3c73SJérôme Glisse * No need to take pmd_lock here, even if some other threads 674da4c3c73SJérôme Glisse * is splitting the huge pmd we will get that event through 675da4c3c73SJérôme Glisse * mmu_notifier callback. 676da4c3c73SJérôme Glisse * 677da4c3c73SJérôme Glisse * So just read pmd value and check again its a transparent 678da4c3c73SJérôme Glisse * huge or device mapping one and compute corresponding pfn 679da4c3c73SJérôme Glisse * values. 680da4c3c73SJérôme Glisse */ 681da4c3c73SJérôme Glisse pmd = pmd_read_atomic(pmdp); 682da4c3c73SJérôme Glisse barrier(); 683da4c3c73SJérôme Glisse if (!pmd_devmap(pmd) && !pmd_trans_huge(pmd)) 684da4c3c73SJérôme Glisse goto again; 685da4c3c73SJérôme Glisse 686d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 68753f5c3f4SJérôme Glisse return hmm_vma_handle_pmd(walk, addr, end, &pfns[i], pmd); 688da4c3c73SJérôme Glisse } 689da4c3c73SJérôme Glisse 690d08faca0SJérôme Glisse /* 691d08faca0SJérôme Glisse * We have handled all the valid case above ie either none, migration, 692d08faca0SJérôme Glisse * huge or transparent huge. At this point either it is a valid pmd 693d08faca0SJérôme Glisse * entry pointing to pte directory or it is a bad pmd that will not 694d08faca0SJérôme Glisse * recover. 695d08faca0SJérôme Glisse */ 696d08faca0SJérôme Glisse if (pmd_bad(pmd)) 697da4c3c73SJérôme Glisse return hmm_pfns_bad(start, end, walk); 698da4c3c73SJérôme Glisse 699da4c3c73SJérôme Glisse ptep = pte_offset_map(pmdp, addr); 700d08faca0SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 701da4c3c73SJérôme Glisse for (; addr < end; addr += PAGE_SIZE, ptep++, i++) { 70253f5c3f4SJérôme Glisse int r; 703da4c3c73SJérôme Glisse 70453f5c3f4SJérôme Glisse r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, &pfns[i]); 70553f5c3f4SJérôme Glisse if (r) { 70653f5c3f4SJérôme Glisse /* hmm_vma_handle_pte() did unmap pte directory */ 70774eee180SJérôme Glisse hmm_vma_walk->last = addr; 70853f5c3f4SJérôme Glisse return r; 70974eee180SJérôme Glisse } 710da4c3c73SJérôme Glisse } 711992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 712992de9a8SJérôme Glisse /* 713992de9a8SJérôme Glisse * We do put_dev_pagemap() here and not in hmm_vma_handle_pte() 714992de9a8SJérôme Glisse * so that we can leverage get_dev_pagemap() optimization which 715992de9a8SJérôme Glisse * will not re-take a reference on a pgmap if we already have 716992de9a8SJérôme Glisse * one. 717992de9a8SJérôme Glisse */ 718992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 719992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 720992de9a8SJérôme Glisse } 721da4c3c73SJérôme Glisse pte_unmap(ptep - 1); 722da4c3c73SJérôme Glisse 72353f5c3f4SJérôme Glisse hmm_vma_walk->last = addr; 724da4c3c73SJérôme Glisse return 0; 725da4c3c73SJérôme Glisse } 726da4c3c73SJérôme Glisse 727992de9a8SJérôme Glisse static int hmm_vma_walk_pud(pud_t *pudp, 728992de9a8SJérôme Glisse unsigned long start, 729992de9a8SJérôme Glisse unsigned long end, 730992de9a8SJérôme Glisse struct mm_walk *walk) 731992de9a8SJérôme Glisse { 732992de9a8SJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 733992de9a8SJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 734992de9a8SJérôme Glisse unsigned long addr = start, next; 735992de9a8SJérôme Glisse pmd_t *pmdp; 736992de9a8SJérôme Glisse pud_t pud; 737992de9a8SJérôme Glisse int ret; 738992de9a8SJérôme Glisse 739992de9a8SJérôme Glisse again: 740992de9a8SJérôme Glisse pud = READ_ONCE(*pudp); 741992de9a8SJérôme Glisse if (pud_none(pud)) 742992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 743992de9a8SJérôme Glisse 744992de9a8SJérôme Glisse if (pud_huge(pud) && pud_devmap(pud)) { 745992de9a8SJérôme Glisse unsigned long i, npages, pfn; 746992de9a8SJérôme Glisse uint64_t *pfns, cpu_flags; 747992de9a8SJérôme Glisse bool fault, write_fault; 748992de9a8SJérôme Glisse 749992de9a8SJérôme Glisse if (!pud_present(pud)) 750992de9a8SJérôme Glisse return hmm_vma_walk_hole(start, end, walk); 751992de9a8SJérôme Glisse 752992de9a8SJérôme Glisse i = (addr - range->start) >> PAGE_SHIFT; 753992de9a8SJérôme Glisse npages = (end - addr) >> PAGE_SHIFT; 754992de9a8SJérôme Glisse pfns = &range->pfns[i]; 755992de9a8SJérôme Glisse 756992de9a8SJérôme Glisse cpu_flags = pud_to_hmm_pfn_flags(range, pud); 757992de9a8SJérôme Glisse hmm_range_need_fault(hmm_vma_walk, pfns, npages, 758992de9a8SJérôme Glisse cpu_flags, &fault, &write_fault); 759992de9a8SJérôme Glisse if (fault || write_fault) 760992de9a8SJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, 761992de9a8SJérôme Glisse write_fault, walk); 762992de9a8SJérôme Glisse 763992de9a8SJérôme Glisse pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); 764992de9a8SJérôme Glisse for (i = 0; i < npages; ++i, ++pfn) { 765992de9a8SJérôme Glisse hmm_vma_walk->pgmap = get_dev_pagemap(pfn, 766992de9a8SJérôme Glisse hmm_vma_walk->pgmap); 767992de9a8SJérôme Glisse if (unlikely(!hmm_vma_walk->pgmap)) 768992de9a8SJérôme Glisse return -EBUSY; 769391aab11SJérôme Glisse pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 770391aab11SJérôme Glisse cpu_flags; 771992de9a8SJérôme Glisse } 772992de9a8SJérôme Glisse if (hmm_vma_walk->pgmap) { 773992de9a8SJérôme Glisse put_dev_pagemap(hmm_vma_walk->pgmap); 774992de9a8SJérôme Glisse hmm_vma_walk->pgmap = NULL; 775992de9a8SJérôme Glisse } 776992de9a8SJérôme Glisse hmm_vma_walk->last = end; 777992de9a8SJérôme Glisse return 0; 778992de9a8SJérôme Glisse } 779992de9a8SJérôme Glisse 780992de9a8SJérôme Glisse split_huge_pud(walk->vma, pudp, addr); 781992de9a8SJérôme Glisse if (pud_none(*pudp)) 782992de9a8SJérôme Glisse goto again; 783992de9a8SJérôme Glisse 784992de9a8SJérôme Glisse pmdp = pmd_offset(pudp, addr); 785992de9a8SJérôme Glisse do { 786992de9a8SJérôme Glisse next = pmd_addr_end(addr, end); 787992de9a8SJérôme Glisse ret = hmm_vma_walk_pmd(pmdp, addr, next, walk); 788992de9a8SJérôme Glisse if (ret) 789992de9a8SJérôme Glisse return ret; 790992de9a8SJérôme Glisse } while (pmdp++, addr = next, addr != end); 791992de9a8SJérôme Glisse 792992de9a8SJérôme Glisse return 0; 793992de9a8SJérôme Glisse } 794992de9a8SJérôme Glisse 79563d5066fSJérôme Glisse static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, 79663d5066fSJérôme Glisse unsigned long start, unsigned long end, 79763d5066fSJérôme Glisse struct mm_walk *walk) 79863d5066fSJérôme Glisse { 79963d5066fSJérôme Glisse #ifdef CONFIG_HUGETLB_PAGE 80063d5066fSJérôme Glisse unsigned long addr = start, i, pfn, mask, size, pfn_inc; 80163d5066fSJérôme Glisse struct hmm_vma_walk *hmm_vma_walk = walk->private; 80263d5066fSJérôme Glisse struct hmm_range *range = hmm_vma_walk->range; 80363d5066fSJérôme Glisse struct vm_area_struct *vma = walk->vma; 80463d5066fSJérôme Glisse struct hstate *h = hstate_vma(vma); 80563d5066fSJérôme Glisse uint64_t orig_pfn, cpu_flags; 80663d5066fSJérôme Glisse bool fault, write_fault; 80763d5066fSJérôme Glisse spinlock_t *ptl; 80863d5066fSJérôme Glisse pte_t entry; 80963d5066fSJérôme Glisse int ret = 0; 81063d5066fSJérôme Glisse 81163d5066fSJérôme Glisse size = 1UL << huge_page_shift(h); 81263d5066fSJérôme Glisse mask = size - 1; 81363d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) { 81463d5066fSJérôme Glisse /* Make sure we are looking at full page. */ 81563d5066fSJérôme Glisse if (start & mask) 81663d5066fSJérôme Glisse return -EINVAL; 81763d5066fSJérôme Glisse if (end < (start + size)) 81863d5066fSJérôme Glisse return -EINVAL; 81963d5066fSJérôme Glisse pfn_inc = size >> PAGE_SHIFT; 82063d5066fSJérôme Glisse } else { 82163d5066fSJérôme Glisse pfn_inc = 1; 82263d5066fSJérôme Glisse size = PAGE_SIZE; 82363d5066fSJérôme Glisse } 82463d5066fSJérôme Glisse 82563d5066fSJérôme Glisse 82663d5066fSJérôme Glisse ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); 82763d5066fSJérôme Glisse entry = huge_ptep_get(pte); 82863d5066fSJérôme Glisse 82963d5066fSJérôme Glisse i = (start - range->start) >> range->page_shift; 83063d5066fSJérôme Glisse orig_pfn = range->pfns[i]; 83163d5066fSJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 83263d5066fSJérôme Glisse cpu_flags = pte_to_hmm_pfn_flags(range, entry); 83363d5066fSJérôme Glisse fault = write_fault = false; 83463d5066fSJérôme Glisse hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, 83563d5066fSJérôme Glisse &fault, &write_fault); 83663d5066fSJérôme Glisse if (fault || write_fault) { 83763d5066fSJérôme Glisse ret = -ENOENT; 83863d5066fSJérôme Glisse goto unlock; 83963d5066fSJérôme Glisse } 84063d5066fSJérôme Glisse 84163d5066fSJérôme Glisse pfn = pte_pfn(entry) + ((start & mask) >> range->page_shift); 84263d5066fSJérôme Glisse for (; addr < end; addr += size, i++, pfn += pfn_inc) 843391aab11SJérôme Glisse range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | 844391aab11SJérôme Glisse cpu_flags; 84563d5066fSJérôme Glisse hmm_vma_walk->last = end; 84663d5066fSJérôme Glisse 84763d5066fSJérôme Glisse unlock: 84863d5066fSJérôme Glisse spin_unlock(ptl); 84963d5066fSJérôme Glisse 85063d5066fSJérôme Glisse if (ret == -ENOENT) 85163d5066fSJérôme Glisse return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk); 85263d5066fSJérôme Glisse 85363d5066fSJérôme Glisse return ret; 85463d5066fSJérôme Glisse #else /* CONFIG_HUGETLB_PAGE */ 85563d5066fSJérôme Glisse return -EINVAL; 85663d5066fSJérôme Glisse #endif 85763d5066fSJérôme Glisse } 85863d5066fSJérôme Glisse 859f88a1e90SJérôme Glisse static void hmm_pfns_clear(struct hmm_range *range, 860f88a1e90SJérôme Glisse uint64_t *pfns, 86133cd47dcSJérôme Glisse unsigned long addr, 86233cd47dcSJérôme Glisse unsigned long end) 86333cd47dcSJérôme Glisse { 86433cd47dcSJérôme Glisse for (; addr < end; addr += PAGE_SIZE, pfns++) 865f88a1e90SJérôme Glisse *pfns = range->values[HMM_PFN_NONE]; 86633cd47dcSJérôme Glisse } 86733cd47dcSJérôme Glisse 868da4c3c73SJérôme Glisse /* 869a3e0d41cSJérôme Glisse * hmm_range_register() - start tracking change to CPU page table over a range 870a3e0d41cSJérôme Glisse * @range: range 871a3e0d41cSJérôme Glisse * @mm: the mm struct for the range of virtual address 872a3e0d41cSJérôme Glisse * @start: start virtual address (inclusive) 873a3e0d41cSJérôme Glisse * @end: end virtual address (exclusive) 87463d5066fSJérôme Glisse * @page_shift: expect page shift for the range 875a3e0d41cSJérôme Glisse * Returns 0 on success, -EFAULT if the address space is no longer valid 876a3e0d41cSJérôme Glisse * 877a3e0d41cSJérôme Glisse * Track updates to the CPU page table see include/linux/hmm.h 878a3e0d41cSJérôme Glisse */ 879a3e0d41cSJérôme Glisse int hmm_range_register(struct hmm_range *range, 880e36acfe6SJason Gunthorpe struct hmm_mirror *mirror, 881a3e0d41cSJérôme Glisse unsigned long start, 88263d5066fSJérôme Glisse unsigned long end, 88363d5066fSJérôme Glisse unsigned page_shift) 884a3e0d41cSJérôme Glisse { 88563d5066fSJérôme Glisse unsigned long mask = ((1UL << page_shift) - 1UL); 886e36acfe6SJason Gunthorpe struct hmm *hmm = mirror->hmm; 88763d5066fSJérôme Glisse 888a3e0d41cSJérôme Glisse range->valid = false; 889a3e0d41cSJérôme Glisse range->hmm = NULL; 890a3e0d41cSJérôme Glisse 89163d5066fSJérôme Glisse if ((start & mask) || (end & mask)) 89263d5066fSJérôme Glisse return -EINVAL; 89363d5066fSJérôme Glisse if (start >= end) 894a3e0d41cSJérôme Glisse return -EINVAL; 895a3e0d41cSJérôme Glisse 89663d5066fSJérôme Glisse range->page_shift = page_shift; 897a3e0d41cSJérôme Glisse range->start = start; 898a3e0d41cSJérôme Glisse range->end = end; 899a3e0d41cSJérôme Glisse 900*47f24598SJason Gunthorpe /* Prevent hmm_release() from running while the range is valid */ 901*47f24598SJason Gunthorpe if (!mmget_not_zero(hmm->mm)) 902a3e0d41cSJérôme Glisse return -EFAULT; 903a3e0d41cSJérôme Glisse 904085ea250SRalph Campbell /* Initialize range to track CPU page table updates. */ 905085ea250SRalph Campbell mutex_lock(&hmm->lock); 906a3e0d41cSJérôme Glisse 907085ea250SRalph Campbell range->hmm = hmm; 908e36acfe6SJason Gunthorpe kref_get(&hmm->kref); 909157816f3SJason Gunthorpe list_add(&range->list, &hmm->ranges); 910a3e0d41cSJérôme Glisse 911a3e0d41cSJérôme Glisse /* 912a3e0d41cSJérôme Glisse * If there are any concurrent notifiers we have to wait for them for 913a3e0d41cSJérôme Glisse * the range to be valid (see hmm_range_wait_until_valid()). 914a3e0d41cSJérôme Glisse */ 915085ea250SRalph Campbell if (!hmm->notifiers) 916a3e0d41cSJérôme Glisse range->valid = true; 917085ea250SRalph Campbell mutex_unlock(&hmm->lock); 918a3e0d41cSJérôme Glisse 919a3e0d41cSJérôme Glisse return 0; 920a3e0d41cSJérôme Glisse } 921a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_register); 922a3e0d41cSJérôme Glisse 923a3e0d41cSJérôme Glisse /* 924a3e0d41cSJérôme Glisse * hmm_range_unregister() - stop tracking change to CPU page table over a range 925a3e0d41cSJérôme Glisse * @range: range 926a3e0d41cSJérôme Glisse * 927a3e0d41cSJérôme Glisse * Range struct is used to track updates to the CPU page table after a call to 928a3e0d41cSJérôme Glisse * hmm_range_register(). See include/linux/hmm.h for how to use it. 929a3e0d41cSJérôme Glisse */ 930a3e0d41cSJérôme Glisse void hmm_range_unregister(struct hmm_range *range) 931a3e0d41cSJérôme Glisse { 932085ea250SRalph Campbell struct hmm *hmm = range->hmm; 933085ea250SRalph Campbell 934a3e0d41cSJérôme Glisse /* Sanity check this really should not happen. */ 935085ea250SRalph Campbell if (hmm == NULL || range->end <= range->start) 936a3e0d41cSJérôme Glisse return; 937a3e0d41cSJérôme Glisse 938085ea250SRalph Campbell mutex_lock(&hmm->lock); 939*47f24598SJason Gunthorpe list_del_init(&range->list); 940085ea250SRalph Campbell mutex_unlock(&hmm->lock); 941a3e0d41cSJérôme Glisse 942a3e0d41cSJérôme Glisse /* Drop reference taken by hmm_range_register() */ 943a3e0d41cSJérôme Glisse range->valid = false; 944*47f24598SJason Gunthorpe mmput(hmm->mm); 945085ea250SRalph Campbell hmm_put(hmm); 946a3e0d41cSJérôme Glisse range->hmm = NULL; 947a3e0d41cSJérôme Glisse } 948a3e0d41cSJérôme Glisse EXPORT_SYMBOL(hmm_range_unregister); 949a3e0d41cSJérôme Glisse 950a3e0d41cSJérôme Glisse /* 95125f23a0cSJérôme Glisse * hmm_range_snapshot() - snapshot CPU page table for a range 95225f23a0cSJérôme Glisse * @range: range 953085ea250SRalph Campbell * Return: -EINVAL if invalid argument, -ENOMEM out of memory, -EPERM invalid 954a3e0d41cSJérôme Glisse * permission (for instance asking for write and range is read only), 955a3e0d41cSJérôme Glisse * -EAGAIN if you need to retry, -EFAULT invalid (ie either no valid 956a3e0d41cSJérôme Glisse * vma or it is illegal to access that range), number of valid pages 957a3e0d41cSJérôme Glisse * in range->pfns[] (from range start address). 958da4c3c73SJérôme Glisse * 959da4c3c73SJérôme Glisse * This snapshots the CPU page table for a range of virtual addresses. Snapshot 960a3e0d41cSJérôme Glisse * validity is tracked by range struct. See in include/linux/hmm.h for example 961a3e0d41cSJérôme Glisse * on how to use. 962da4c3c73SJérôme Glisse */ 96325f23a0cSJérôme Glisse long hmm_range_snapshot(struct hmm_range *range) 964da4c3c73SJérôme Glisse { 96563d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 966a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 96774eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 968a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 969a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 970da4c3c73SJérôme Glisse struct mm_walk mm_walk; 971704f3f2cSJérôme Glisse 972*47f24598SJason Gunthorpe lockdep_assert_held(&hmm->mm->mmap_sem); 973a3e0d41cSJérôme Glisse do { 974a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 975a3e0d41cSJérôme Glisse if (!range->valid) 976a3e0d41cSJérôme Glisse return -EAGAIN; 977a3e0d41cSJérôme Glisse 978a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 97963d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 980a3e0d41cSJérôme Glisse return -EFAULT; 981a3e0d41cSJérôme Glisse 98263d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 9831c2308f0SJason Gunthorpe if (huge_page_shift(hstate_vma(vma)) != 9841c2308f0SJason Gunthorpe range->page_shift && 98563d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 98663d5066fSJérôme Glisse return -EINVAL; 98763d5066fSJérôme Glisse } else { 98863d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 98963d5066fSJérôme Glisse return -EINVAL; 99063d5066fSJérôme Glisse } 99163d5066fSJérôme Glisse 99286586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 99386586a41SJérôme Glisse /* 994a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 995a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 996a3e0d41cSJérôme Glisse * support architecture that allow write without read. 99786586a41SJérôme Glisse */ 998a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 999a3e0d41cSJérôme Glisse range->start, range->end); 100086586a41SJérôme Glisse return -EPERM; 100186586a41SJérôme Glisse } 100286586a41SJérôme Glisse 1003a3e0d41cSJérôme Glisse range->vma = vma; 1004992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1005a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 100674eee180SJérôme Glisse hmm_vma_walk.fault = false; 100774eee180SJérôme Glisse hmm_vma_walk.range = range; 100874eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1009a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 101074eee180SJérôme Glisse 1011da4c3c73SJérôme Glisse mm_walk.vma = vma; 1012da4c3c73SJérôme Glisse mm_walk.mm = vma->vm_mm; 1013da4c3c73SJérôme Glisse mm_walk.pte_entry = NULL; 1014da4c3c73SJérôme Glisse mm_walk.test_walk = NULL; 1015da4c3c73SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1016992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 1017da4c3c73SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 1018da4c3c73SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 101963d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 1020da4c3c73SJérôme Glisse 1021a3e0d41cSJérôme Glisse walk_page_range(start, end, &mm_walk); 1022a3e0d41cSJérôme Glisse start = end; 1023a3e0d41cSJérôme Glisse } while (start < range->end); 1024a3e0d41cSJérôme Glisse 102525f23a0cSJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1026da4c3c73SJérôme Glisse } 102725f23a0cSJérôme Glisse EXPORT_SYMBOL(hmm_range_snapshot); 1028da4c3c73SJérôme Glisse 1029da4c3c73SJérôme Glisse /* 103073231612SJérôme Glisse * hmm_range_fault() - try to fault some address in a virtual address range 103108232a45SJérôme Glisse * @range: range being faulted 103274eee180SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1033085ea250SRalph Campbell * Return: number of valid pages in range->pfns[] (from range start 103473231612SJérôme Glisse * address). This may be zero. If the return value is negative, 103573231612SJérôme Glisse * then one of the following values may be returned: 103673231612SJérôme Glisse * 103773231612SJérôme Glisse * -EINVAL invalid arguments or mm or virtual address are in an 103863d5066fSJérôme Glisse * invalid vma (for instance device file vma). 103973231612SJérôme Glisse * -ENOMEM: Out of memory. 104073231612SJérôme Glisse * -EPERM: Invalid permission (for instance asking for write and 104173231612SJérôme Glisse * range is read only). 104273231612SJérôme Glisse * -EAGAIN: If you need to retry and mmap_sem was drop. This can only 104373231612SJérôme Glisse * happens if block argument is false. 104473231612SJérôme Glisse * -EBUSY: If the the range is being invalidated and you should wait 104573231612SJérôme Glisse * for invalidation to finish. 104673231612SJérôme Glisse * -EFAULT: Invalid (ie either no valid vma or it is illegal to access 104773231612SJérôme Glisse * that range), number of valid pages in range->pfns[] (from 104873231612SJérôme Glisse * range start address). 104974eee180SJérôme Glisse * 105074eee180SJérôme Glisse * This is similar to a regular CPU page fault except that it will not trigger 105173231612SJérôme Glisse * any memory migration if the memory being faulted is not accessible by CPUs 105273231612SJérôme Glisse * and caller does not ask for migration. 105374eee180SJérôme Glisse * 1054ff05c0c6SJérôme Glisse * On error, for one virtual address in the range, the function will mark the 1055ff05c0c6SJérôme Glisse * corresponding HMM pfn entry with an error flag. 105674eee180SJérôme Glisse */ 105773231612SJérôme Glisse long hmm_range_fault(struct hmm_range *range, bool block) 105874eee180SJérôme Glisse { 105963d5066fSJérôme Glisse const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; 1060a3e0d41cSJérôme Glisse unsigned long start = range->start, end; 106174eee180SJérôme Glisse struct hmm_vma_walk hmm_vma_walk; 1062a3e0d41cSJérôme Glisse struct hmm *hmm = range->hmm; 1063a3e0d41cSJérôme Glisse struct vm_area_struct *vma; 106474eee180SJérôme Glisse struct mm_walk mm_walk; 106574eee180SJérôme Glisse int ret; 106674eee180SJérôme Glisse 1067*47f24598SJason Gunthorpe lockdep_assert_held(&hmm->mm->mmap_sem); 1068a3e0d41cSJérôme Glisse 1069a3e0d41cSJérôme Glisse do { 1070a3e0d41cSJérôme Glisse /* If range is no longer valid force retry. */ 1071a3e0d41cSJérôme Glisse if (!range->valid) { 1072a3e0d41cSJérôme Glisse up_read(&hmm->mm->mmap_sem); 1073a3e0d41cSJérôme Glisse return -EAGAIN; 1074704f3f2cSJérôme Glisse } 107574eee180SJérôme Glisse 1076a3e0d41cSJérôme Glisse vma = find_vma(hmm->mm, start); 107763d5066fSJérôme Glisse if (vma == NULL || (vma->vm_flags & device_vma)) 1078a3e0d41cSJérôme Glisse return -EFAULT; 1079a3e0d41cSJérôme Glisse 108063d5066fSJérôme Glisse if (is_vm_hugetlb_page(vma)) { 108163d5066fSJérôme Glisse if (huge_page_shift(hstate_vma(vma)) != 108263d5066fSJérôme Glisse range->page_shift && 108363d5066fSJérôme Glisse range->page_shift != PAGE_SHIFT) 108463d5066fSJérôme Glisse return -EINVAL; 108563d5066fSJérôme Glisse } else { 108663d5066fSJérôme Glisse if (range->page_shift != PAGE_SHIFT) 108763d5066fSJérôme Glisse return -EINVAL; 108863d5066fSJérôme Glisse } 108963d5066fSJérôme Glisse 109086586a41SJérôme Glisse if (!(vma->vm_flags & VM_READ)) { 109186586a41SJérôme Glisse /* 1092a3e0d41cSJérôme Glisse * If vma do not allow read access, then assume that it 1093a3e0d41cSJérôme Glisse * does not allow write access, either. HMM does not 1094a3e0d41cSJérôme Glisse * support architecture that allow write without read. 109586586a41SJérôme Glisse */ 1096a3e0d41cSJérôme Glisse hmm_pfns_clear(range, range->pfns, 1097a3e0d41cSJérôme Glisse range->start, range->end); 109886586a41SJérôme Glisse return -EPERM; 109986586a41SJérôme Glisse } 110074eee180SJérôme Glisse 1101a3e0d41cSJérôme Glisse range->vma = vma; 1102992de9a8SJérôme Glisse hmm_vma_walk.pgmap = NULL; 1103a3e0d41cSJérôme Glisse hmm_vma_walk.last = start; 110474eee180SJérôme Glisse hmm_vma_walk.fault = true; 110574eee180SJérôme Glisse hmm_vma_walk.block = block; 110674eee180SJérôme Glisse hmm_vma_walk.range = range; 110774eee180SJérôme Glisse mm_walk.private = &hmm_vma_walk; 1108a3e0d41cSJérôme Glisse end = min(range->end, vma->vm_end); 110974eee180SJérôme Glisse 111074eee180SJérôme Glisse mm_walk.vma = vma; 111174eee180SJérôme Glisse mm_walk.mm = vma->vm_mm; 111274eee180SJérôme Glisse mm_walk.pte_entry = NULL; 111374eee180SJérôme Glisse mm_walk.test_walk = NULL; 111474eee180SJérôme Glisse mm_walk.hugetlb_entry = NULL; 1115992de9a8SJérôme Glisse mm_walk.pud_entry = hmm_vma_walk_pud; 111674eee180SJérôme Glisse mm_walk.pmd_entry = hmm_vma_walk_pmd; 111774eee180SJérôme Glisse mm_walk.pte_hole = hmm_vma_walk_hole; 111863d5066fSJérôme Glisse mm_walk.hugetlb_entry = hmm_vma_walk_hugetlb_entry; 111974eee180SJérôme Glisse 112074eee180SJérôme Glisse do { 1121a3e0d41cSJérôme Glisse ret = walk_page_range(start, end, &mm_walk); 112274eee180SJérôme Glisse start = hmm_vma_walk.last; 1123a3e0d41cSJérôme Glisse 112473231612SJérôme Glisse /* Keep trying while the range is valid. */ 112573231612SJérôme Glisse } while (ret == -EBUSY && range->valid); 112674eee180SJérôme Glisse 112774eee180SJérôme Glisse if (ret) { 112874eee180SJérôme Glisse unsigned long i; 112974eee180SJérôme Glisse 113074eee180SJérôme Glisse i = (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 1131a3e0d41cSJérôme Glisse hmm_pfns_clear(range, &range->pfns[i], 1132a3e0d41cSJérôme Glisse hmm_vma_walk.last, range->end); 113373231612SJérôme Glisse return ret; 113474eee180SJérôme Glisse } 1135a3e0d41cSJérôme Glisse start = end; 1136a3e0d41cSJérôme Glisse 1137a3e0d41cSJérôme Glisse } while (start < range->end); 1138704f3f2cSJérôme Glisse 113973231612SJérôme Glisse return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; 114074eee180SJérôme Glisse } 114173231612SJérôme Glisse EXPORT_SYMBOL(hmm_range_fault); 114255c0ece8SJérôme Glisse 114355c0ece8SJérôme Glisse /** 114455c0ece8SJérôme Glisse * hmm_range_dma_map() - hmm_range_fault() and dma map page all in one. 114555c0ece8SJérôme Glisse * @range: range being faulted 114655c0ece8SJérôme Glisse * @device: device against to dma map page to 114755c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 114855c0ece8SJérôme Glisse * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem) 1149085ea250SRalph Campbell * Return: number of pages mapped on success, -EAGAIN if mmap_sem have been 115055c0ece8SJérôme Glisse * drop and you need to try again, some other error value otherwise 115155c0ece8SJérôme Glisse * 115255c0ece8SJérôme Glisse * Note same usage pattern as hmm_range_fault(). 115355c0ece8SJérôme Glisse */ 115455c0ece8SJérôme Glisse long hmm_range_dma_map(struct hmm_range *range, 115555c0ece8SJérôme Glisse struct device *device, 115655c0ece8SJérôme Glisse dma_addr_t *daddrs, 115755c0ece8SJérôme Glisse bool block) 115855c0ece8SJérôme Glisse { 115955c0ece8SJérôme Glisse unsigned long i, npages, mapped; 116055c0ece8SJérôme Glisse long ret; 116155c0ece8SJérôme Glisse 116255c0ece8SJérôme Glisse ret = hmm_range_fault(range, block); 116355c0ece8SJérôme Glisse if (ret <= 0) 116455c0ece8SJérôme Glisse return ret ? ret : -EBUSY; 116555c0ece8SJérôme Glisse 116655c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 116755c0ece8SJérôme Glisse for (i = 0, mapped = 0; i < npages; ++i) { 116855c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 116955c0ece8SJérôme Glisse struct page *page; 117055c0ece8SJérôme Glisse 117155c0ece8SJérôme Glisse /* 117255c0ece8SJérôme Glisse * FIXME need to update DMA API to provide invalid DMA address 117355c0ece8SJérôme Glisse * value instead of a function to test dma address value. This 117455c0ece8SJérôme Glisse * would remove lot of dumb code duplicated accross many arch. 117555c0ece8SJérôme Glisse * 117655c0ece8SJérôme Glisse * For now setting it to 0 here is good enough as the pfns[] 117755c0ece8SJérôme Glisse * value is what is use to check what is valid and what isn't. 117855c0ece8SJérôme Glisse */ 117955c0ece8SJérôme Glisse daddrs[i] = 0; 118055c0ece8SJérôme Glisse 1181391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 118255c0ece8SJérôme Glisse if (page == NULL) 118355c0ece8SJérôme Glisse continue; 118455c0ece8SJérôme Glisse 118555c0ece8SJérôme Glisse /* Check if range is being invalidated */ 118655c0ece8SJérôme Glisse if (!range->valid) { 118755c0ece8SJérôme Glisse ret = -EBUSY; 118855c0ece8SJérôme Glisse goto unmap; 118955c0ece8SJérôme Glisse } 119055c0ece8SJérôme Glisse 119155c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 119255c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) 119355c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 119455c0ece8SJérôme Glisse 119555c0ece8SJérôme Glisse daddrs[i] = dma_map_page(device, page, 0, PAGE_SIZE, dir); 119655c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) { 119755c0ece8SJérôme Glisse ret = -EFAULT; 119855c0ece8SJérôme Glisse goto unmap; 119955c0ece8SJérôme Glisse } 120055c0ece8SJérôme Glisse 120155c0ece8SJérôme Glisse mapped++; 120255c0ece8SJérôme Glisse } 120355c0ece8SJérôme Glisse 120455c0ece8SJérôme Glisse return mapped; 120555c0ece8SJérôme Glisse 120655c0ece8SJérôme Glisse unmap: 120755c0ece8SJérôme Glisse for (npages = i, i = 0; (i < npages) && mapped; ++i) { 120855c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 120955c0ece8SJérôme Glisse struct page *page; 121055c0ece8SJérôme Glisse 1211391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 121255c0ece8SJérôme Glisse if (page == NULL) 121355c0ece8SJérôme Glisse continue; 121455c0ece8SJérôme Glisse 121555c0ece8SJérôme Glisse if (dma_mapping_error(device, daddrs[i])) 121655c0ece8SJérôme Glisse continue; 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 dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 122355c0ece8SJérôme Glisse mapped--; 122455c0ece8SJérôme Glisse } 122555c0ece8SJérôme Glisse 122655c0ece8SJérôme Glisse return ret; 122755c0ece8SJérôme Glisse } 122855c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_map); 122955c0ece8SJérôme Glisse 123055c0ece8SJérôme Glisse /** 123155c0ece8SJérôme Glisse * hmm_range_dma_unmap() - unmap range of that was map with hmm_range_dma_map() 123255c0ece8SJérôme Glisse * @range: range being unmapped 123355c0ece8SJérôme Glisse * @vma: the vma against which the range (optional) 123455c0ece8SJérôme Glisse * @device: device against which dma map was done 123555c0ece8SJérôme Glisse * @daddrs: dma address of mapped pages 123655c0ece8SJérôme Glisse * @dirty: dirty page if it had the write flag set 1237085ea250SRalph Campbell * Return: number of page unmapped on success, -EINVAL otherwise 123855c0ece8SJérôme Glisse * 123955c0ece8SJérôme Glisse * Note that caller MUST abide by mmu notifier or use HMM mirror and abide 124055c0ece8SJérôme Glisse * to the sync_cpu_device_pagetables() callback so that it is safe here to 124155c0ece8SJérôme Glisse * call set_page_dirty(). Caller must also take appropriate locks to avoid 124255c0ece8SJérôme Glisse * concurrent mmu notifier or sync_cpu_device_pagetables() to make progress. 124355c0ece8SJérôme Glisse */ 124455c0ece8SJérôme Glisse long hmm_range_dma_unmap(struct hmm_range *range, 124555c0ece8SJérôme Glisse struct vm_area_struct *vma, 124655c0ece8SJérôme Glisse struct device *device, 124755c0ece8SJérôme Glisse dma_addr_t *daddrs, 124855c0ece8SJérôme Glisse bool dirty) 124955c0ece8SJérôme Glisse { 125055c0ece8SJérôme Glisse unsigned long i, npages; 125155c0ece8SJérôme Glisse long cpages = 0; 125255c0ece8SJérôme Glisse 125355c0ece8SJérôme Glisse /* Sanity check. */ 125455c0ece8SJérôme Glisse if (range->end <= range->start) 125555c0ece8SJérôme Glisse return -EINVAL; 125655c0ece8SJérôme Glisse if (!daddrs) 125755c0ece8SJérôme Glisse return -EINVAL; 125855c0ece8SJérôme Glisse if (!range->pfns) 125955c0ece8SJérôme Glisse return -EINVAL; 126055c0ece8SJérôme Glisse 126155c0ece8SJérôme Glisse npages = (range->end - range->start) >> PAGE_SHIFT; 126255c0ece8SJérôme Glisse for (i = 0; i < npages; ++i) { 126355c0ece8SJérôme Glisse enum dma_data_direction dir = DMA_TO_DEVICE; 126455c0ece8SJérôme Glisse struct page *page; 126555c0ece8SJérôme Glisse 1266391aab11SJérôme Glisse page = hmm_device_entry_to_page(range, range->pfns[i]); 126755c0ece8SJérôme Glisse if (page == NULL) 126855c0ece8SJérôme Glisse continue; 126955c0ece8SJérôme Glisse 127055c0ece8SJérôme Glisse /* If it is read and write than map bi-directional. */ 127155c0ece8SJérôme Glisse if (range->pfns[i] & range->flags[HMM_PFN_WRITE]) { 127255c0ece8SJérôme Glisse dir = DMA_BIDIRECTIONAL; 127355c0ece8SJérôme Glisse 127455c0ece8SJérôme Glisse /* 127555c0ece8SJérôme Glisse * See comments in function description on why it is 127655c0ece8SJérôme Glisse * safe here to call set_page_dirty() 127755c0ece8SJérôme Glisse */ 127855c0ece8SJérôme Glisse if (dirty) 127955c0ece8SJérôme Glisse set_page_dirty(page); 128055c0ece8SJérôme Glisse } 128155c0ece8SJérôme Glisse 128255c0ece8SJérôme Glisse /* Unmap and clear pfns/dma address */ 128355c0ece8SJérôme Glisse dma_unmap_page(device, daddrs[i], PAGE_SIZE, dir); 128455c0ece8SJérôme Glisse range->pfns[i] = range->values[HMM_PFN_NONE]; 128555c0ece8SJérôme Glisse /* FIXME see comments in hmm_vma_dma_map() */ 128655c0ece8SJérôme Glisse daddrs[i] = 0; 128755c0ece8SJérôme Glisse cpages++; 128855c0ece8SJérôme Glisse } 128955c0ece8SJérôme Glisse 129055c0ece8SJérôme Glisse return cpages; 129155c0ece8SJérôme Glisse } 129255c0ece8SJérôme Glisse EXPORT_SYMBOL(hmm_range_dma_unmap); 1293c0b12405SJérôme Glisse #endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */ 12944ef589dcSJérôme Glisse 12954ef589dcSJérôme Glisse 1296df6ad698SJérôme Glisse #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) 12974ef589dcSJérôme Glisse struct page *hmm_vma_alloc_locked_page(struct vm_area_struct *vma, 12984ef589dcSJérôme Glisse unsigned long addr) 12994ef589dcSJérôme Glisse { 13004ef589dcSJérôme Glisse struct page *page; 13014ef589dcSJérôme Glisse 13024ef589dcSJérôme Glisse page = alloc_page_vma(GFP_HIGHUSER, vma, addr); 13034ef589dcSJérôme Glisse if (!page) 13044ef589dcSJérôme Glisse return NULL; 13054ef589dcSJérôme Glisse lock_page(page); 13064ef589dcSJérôme Glisse return page; 13074ef589dcSJérôme Glisse } 13084ef589dcSJérôme Glisse EXPORT_SYMBOL(hmm_vma_alloc_locked_page); 13094ef589dcSJérôme Glisse 13104ef589dcSJérôme Glisse 13114ef589dcSJérôme Glisse static void hmm_devmem_ref_release(struct percpu_ref *ref) 13124ef589dcSJérôme Glisse { 13134ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13144ef589dcSJérôme Glisse 13154ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 13164ef589dcSJérôme Glisse complete(&devmem->completion); 13174ef589dcSJérôme Glisse } 13184ef589dcSJérôme Glisse 13194ef589dcSJérôme Glisse static void hmm_devmem_ref_exit(void *data) 13204ef589dcSJérôme Glisse { 13214ef589dcSJérôme Glisse struct percpu_ref *ref = data; 13224ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13234ef589dcSJérôme Glisse 13244ef589dcSJérôme Glisse devmem = container_of(ref, struct hmm_devmem, ref); 1325bbecd94eSDan Williams wait_for_completion(&devmem->completion); 13264ef589dcSJérôme Glisse percpu_ref_exit(ref); 13274ef589dcSJérôme Glisse } 13284ef589dcSJérôme Glisse 1329bbecd94eSDan Williams static void hmm_devmem_ref_kill(struct percpu_ref *ref) 13304ef589dcSJérôme Glisse { 13314ef589dcSJérôme Glisse percpu_ref_kill(ref); 13324ef589dcSJérôme Glisse } 13334ef589dcSJérôme Glisse 1334b57e622eSSouptick Joarder static vm_fault_t hmm_devmem_fault(struct vm_area_struct *vma, 13354ef589dcSJérôme Glisse unsigned long addr, 13364ef589dcSJérôme Glisse const struct page *page, 13374ef589dcSJérôme Glisse unsigned int flags, 13384ef589dcSJérôme Glisse pmd_t *pmdp) 13394ef589dcSJérôme Glisse { 13404ef589dcSJérôme Glisse struct hmm_devmem *devmem = page->pgmap->data; 13414ef589dcSJérôme Glisse 13424ef589dcSJérôme Glisse return devmem->ops->fault(devmem, vma, addr, page, flags, pmdp); 13434ef589dcSJérôme Glisse } 13444ef589dcSJérôme Glisse 13454ef589dcSJérôme Glisse static void hmm_devmem_free(struct page *page, void *data) 13464ef589dcSJérôme Glisse { 13474ef589dcSJérôme Glisse struct hmm_devmem *devmem = data; 13484ef589dcSJérôme Glisse 13492fa147bdSDan Williams page->mapping = NULL; 13502fa147bdSDan Williams 13514ef589dcSJérôme Glisse devmem->ops->free(devmem, page); 13524ef589dcSJérôme Glisse } 13534ef589dcSJérôme Glisse 13544ef589dcSJérôme Glisse /* 13554ef589dcSJérôme Glisse * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory 13564ef589dcSJérôme Glisse * 13574ef589dcSJérôme Glisse * @ops: memory event device driver callback (see struct hmm_devmem_ops) 13584ef589dcSJérôme Glisse * @device: device struct to bind the resource too 13594ef589dcSJérôme Glisse * @size: size in bytes of the device memory to add 1360085ea250SRalph Campbell * Return: pointer to new hmm_devmem struct ERR_PTR otherwise 13614ef589dcSJérôme Glisse * 13624ef589dcSJérôme Glisse * This function first finds an empty range of physical address big enough to 13634ef589dcSJérôme Glisse * contain the new resource, and then hotplugs it as ZONE_DEVICE memory, which 13644ef589dcSJérôme Glisse * in turn allocates struct pages. It does not do anything beyond that; all 13654ef589dcSJérôme Glisse * events affecting the memory will go through the various callbacks provided 13664ef589dcSJérôme Glisse * by hmm_devmem_ops struct. 13674ef589dcSJérôme Glisse * 13684ef589dcSJérôme Glisse * Device driver should call this function during device initialization and 13694ef589dcSJérôme Glisse * is then responsible of memory management. HMM only provides helpers. 13704ef589dcSJérôme Glisse */ 13714ef589dcSJérôme Glisse struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 13724ef589dcSJérôme Glisse struct device *device, 13734ef589dcSJérôme Glisse unsigned long size) 13744ef589dcSJérôme Glisse { 13754ef589dcSJérôme Glisse struct hmm_devmem *devmem; 13764ef589dcSJérôme Glisse resource_size_t addr; 1377bbecd94eSDan Williams void *result; 13784ef589dcSJérôme Glisse int ret; 13794ef589dcSJérôme Glisse 1380e7638488SDan Williams dev_pagemap_get_ops(); 13814ef589dcSJérôme Glisse 138258ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 13834ef589dcSJérôme Glisse if (!devmem) 13844ef589dcSJérôme Glisse return ERR_PTR(-ENOMEM); 13854ef589dcSJérôme Glisse 13864ef589dcSJérôme Glisse init_completion(&devmem->completion); 13874ef589dcSJérôme Glisse devmem->pfn_first = -1UL; 13884ef589dcSJérôme Glisse devmem->pfn_last = -1UL; 13894ef589dcSJérôme Glisse devmem->resource = NULL; 13904ef589dcSJérôme Glisse devmem->device = device; 13914ef589dcSJérôme Glisse devmem->ops = ops; 13924ef589dcSJérôme Glisse 13934ef589dcSJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 13944ef589dcSJérôme Glisse 0, GFP_KERNEL); 13954ef589dcSJérôme Glisse if (ret) 139658ef15b7SDan Williams return ERR_PTR(ret); 13974ef589dcSJérôme Glisse 139858ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, &devmem->ref); 13994ef589dcSJérôme Glisse if (ret) 140058ef15b7SDan Williams return ERR_PTR(ret); 14014ef589dcSJérôme Glisse 14024ef589dcSJérôme Glisse size = ALIGN(size, PA_SECTION_SIZE); 14034ef589dcSJérôme Glisse addr = min((unsigned long)iomem_resource.end, 14044ef589dcSJérôme Glisse (1UL << MAX_PHYSMEM_BITS) - 1); 14054ef589dcSJérôme Glisse addr = addr - size + 1UL; 14064ef589dcSJérôme Glisse 14074ef589dcSJérôme Glisse /* 14084ef589dcSJérôme Glisse * FIXME add a new helper to quickly walk resource tree and find free 14094ef589dcSJérôme Glisse * range 14104ef589dcSJérôme Glisse * 14114ef589dcSJérôme Glisse * FIXME what about ioport_resource resource ? 14124ef589dcSJérôme Glisse */ 14134ef589dcSJérôme Glisse for (; addr > size && addr >= iomem_resource.start; addr -= size) { 14144ef589dcSJérôme Glisse ret = region_intersects(addr, size, 0, IORES_DESC_NONE); 14154ef589dcSJérôme Glisse if (ret != REGION_DISJOINT) 14164ef589dcSJérôme Glisse continue; 14174ef589dcSJérôme Glisse 14184ef589dcSJérôme Glisse devmem->resource = devm_request_mem_region(device, addr, size, 14194ef589dcSJérôme Glisse dev_name(device)); 142058ef15b7SDan Williams if (!devmem->resource) 142158ef15b7SDan Williams return ERR_PTR(-ENOMEM); 14224ef589dcSJérôme Glisse break; 14234ef589dcSJérôme Glisse } 142458ef15b7SDan Williams if (!devmem->resource) 142558ef15b7SDan Williams return ERR_PTR(-ERANGE); 14264ef589dcSJérôme Glisse 14274ef589dcSJérôme Glisse devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; 14284ef589dcSJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 14294ef589dcSJérôme Glisse devmem->pfn_last = devmem->pfn_first + 14304ef589dcSJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1431063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 14324ef589dcSJérôme Glisse 1433bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; 1434bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1435bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1436bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1437bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1438bbecd94eSDan Williams devmem->pagemap.data = devmem; 1439bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 144058ef15b7SDan Williams 1441bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1442bbecd94eSDan Williams if (IS_ERR(result)) 1443bbecd94eSDan Williams return result; 14444ef589dcSJérôme Glisse return devmem; 14454ef589dcSJérôme Glisse } 144602917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add); 14474ef589dcSJérôme Glisse 1448d3df0a42SJérôme Glisse struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, 1449d3df0a42SJérôme Glisse struct device *device, 1450d3df0a42SJérôme Glisse struct resource *res) 1451d3df0a42SJérôme Glisse { 1452d3df0a42SJérôme Glisse struct hmm_devmem *devmem; 1453bbecd94eSDan Williams void *result; 1454d3df0a42SJérôme Glisse int ret; 1455d3df0a42SJérôme Glisse 1456d3df0a42SJérôme Glisse if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) 1457d3df0a42SJérôme Glisse return ERR_PTR(-EINVAL); 1458d3df0a42SJérôme Glisse 1459e7638488SDan Williams dev_pagemap_get_ops(); 1460d3df0a42SJérôme Glisse 146158ef15b7SDan Williams devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); 1462d3df0a42SJérôme Glisse if (!devmem) 1463d3df0a42SJérôme Glisse return ERR_PTR(-ENOMEM); 1464d3df0a42SJérôme Glisse 1465d3df0a42SJérôme Glisse init_completion(&devmem->completion); 1466d3df0a42SJérôme Glisse devmem->pfn_first = -1UL; 1467d3df0a42SJérôme Glisse devmem->pfn_last = -1UL; 1468d3df0a42SJérôme Glisse devmem->resource = res; 1469d3df0a42SJérôme Glisse devmem->device = device; 1470d3df0a42SJérôme Glisse devmem->ops = ops; 1471d3df0a42SJérôme Glisse 1472d3df0a42SJérôme Glisse ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 1473d3df0a42SJérôme Glisse 0, GFP_KERNEL); 1474d3df0a42SJérôme Glisse if (ret) 147558ef15b7SDan Williams return ERR_PTR(ret); 1476d3df0a42SJérôme Glisse 147758ef15b7SDan Williams ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, 147858ef15b7SDan Williams &devmem->ref); 1479d3df0a42SJérôme Glisse if (ret) 148058ef15b7SDan Williams return ERR_PTR(ret); 1481d3df0a42SJérôme Glisse 1482d3df0a42SJérôme Glisse devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; 1483d3df0a42SJérôme Glisse devmem->pfn_last = devmem->pfn_first + 1484d3df0a42SJérôme Glisse (resource_size(devmem->resource) >> PAGE_SHIFT); 1485063a7d1dSDan Williams devmem->page_fault = hmm_devmem_fault; 1486d3df0a42SJérôme Glisse 1487bbecd94eSDan Williams devmem->pagemap.type = MEMORY_DEVICE_PUBLIC; 1488bbecd94eSDan Williams devmem->pagemap.res = *devmem->resource; 1489bbecd94eSDan Williams devmem->pagemap.page_free = hmm_devmem_free; 1490bbecd94eSDan Williams devmem->pagemap.altmap_valid = false; 1491bbecd94eSDan Williams devmem->pagemap.ref = &devmem->ref; 1492bbecd94eSDan Williams devmem->pagemap.data = devmem; 1493bbecd94eSDan Williams devmem->pagemap.kill = hmm_devmem_ref_kill; 149458ef15b7SDan Williams 1495bbecd94eSDan Williams result = devm_memremap_pages(devmem->device, &devmem->pagemap); 1496bbecd94eSDan Williams if (IS_ERR(result)) 1497bbecd94eSDan Williams return result; 1498d3df0a42SJérôme Glisse return devmem; 1499d3df0a42SJérôme Glisse } 150002917e9fSDan Williams EXPORT_SYMBOL_GPL(hmm_devmem_add_resource); 1501d3df0a42SJérôme Glisse 15024ef589dcSJérôme Glisse /* 1503858b54daSJérôme Glisse * A device driver that wants to handle multiple devices memory through a 1504858b54daSJérôme Glisse * single fake device can use hmm_device to do so. This is purely a helper 1505858b54daSJérôme Glisse * and it is not needed to make use of any HMM functionality. 1506858b54daSJérôme Glisse */ 1507858b54daSJérôme Glisse #define HMM_DEVICE_MAX 256 1508858b54daSJérôme Glisse 1509858b54daSJérôme Glisse static DECLARE_BITMAP(hmm_device_mask, HMM_DEVICE_MAX); 1510858b54daSJérôme Glisse static DEFINE_SPINLOCK(hmm_device_lock); 1511858b54daSJérôme Glisse static struct class *hmm_device_class; 1512858b54daSJérôme Glisse static dev_t hmm_device_devt; 1513858b54daSJérôme Glisse 1514858b54daSJérôme Glisse static void hmm_device_release(struct device *device) 1515858b54daSJérôme Glisse { 1516858b54daSJérôme Glisse struct hmm_device *hmm_device; 1517858b54daSJérôme Glisse 1518858b54daSJérôme Glisse hmm_device = container_of(device, struct hmm_device, device); 1519858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1520858b54daSJérôme Glisse clear_bit(hmm_device->minor, hmm_device_mask); 1521858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1522858b54daSJérôme Glisse 1523858b54daSJérôme Glisse kfree(hmm_device); 1524858b54daSJérôme Glisse } 1525858b54daSJérôme Glisse 1526858b54daSJérôme Glisse struct hmm_device *hmm_device_new(void *drvdata) 1527858b54daSJérôme Glisse { 1528858b54daSJérôme Glisse struct hmm_device *hmm_device; 1529858b54daSJérôme Glisse 1530858b54daSJérôme Glisse hmm_device = kzalloc(sizeof(*hmm_device), GFP_KERNEL); 1531858b54daSJérôme Glisse if (!hmm_device) 1532858b54daSJérôme Glisse return ERR_PTR(-ENOMEM); 1533858b54daSJérôme Glisse 1534858b54daSJérôme Glisse spin_lock(&hmm_device_lock); 1535858b54daSJérôme Glisse hmm_device->minor = find_first_zero_bit(hmm_device_mask, HMM_DEVICE_MAX); 1536858b54daSJérôme Glisse if (hmm_device->minor >= HMM_DEVICE_MAX) { 1537858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1538858b54daSJérôme Glisse kfree(hmm_device); 1539858b54daSJérôme Glisse return ERR_PTR(-EBUSY); 1540858b54daSJérôme Glisse } 1541858b54daSJérôme Glisse set_bit(hmm_device->minor, hmm_device_mask); 1542858b54daSJérôme Glisse spin_unlock(&hmm_device_lock); 1543858b54daSJérôme Glisse 1544858b54daSJérôme Glisse dev_set_name(&hmm_device->device, "hmm_device%d", hmm_device->minor); 1545858b54daSJérôme Glisse hmm_device->device.devt = MKDEV(MAJOR(hmm_device_devt), 1546858b54daSJérôme Glisse hmm_device->minor); 1547858b54daSJérôme Glisse hmm_device->device.release = hmm_device_release; 1548858b54daSJérôme Glisse dev_set_drvdata(&hmm_device->device, drvdata); 1549858b54daSJérôme Glisse hmm_device->device.class = hmm_device_class; 1550858b54daSJérôme Glisse device_initialize(&hmm_device->device); 1551858b54daSJérôme Glisse 1552858b54daSJérôme Glisse return hmm_device; 1553858b54daSJérôme Glisse } 1554858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_new); 1555858b54daSJérôme Glisse 1556858b54daSJérôme Glisse void hmm_device_put(struct hmm_device *hmm_device) 1557858b54daSJérôme Glisse { 1558858b54daSJérôme Glisse put_device(&hmm_device->device); 1559858b54daSJérôme Glisse } 1560858b54daSJérôme Glisse EXPORT_SYMBOL(hmm_device_put); 1561858b54daSJérôme Glisse 1562858b54daSJérôme Glisse static int __init hmm_init(void) 1563858b54daSJérôme Glisse { 1564858b54daSJérôme Glisse int ret; 1565858b54daSJérôme Glisse 1566858b54daSJérôme Glisse ret = alloc_chrdev_region(&hmm_device_devt, 0, 1567858b54daSJérôme Glisse HMM_DEVICE_MAX, 1568858b54daSJérôme Glisse "hmm_device"); 1569858b54daSJérôme Glisse if (ret) 1570858b54daSJérôme Glisse return ret; 1571858b54daSJérôme Glisse 1572858b54daSJérôme Glisse hmm_device_class = class_create(THIS_MODULE, "hmm_device"); 1573858b54daSJérôme Glisse if (IS_ERR(hmm_device_class)) { 1574858b54daSJérôme Glisse unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX); 1575858b54daSJérôme Glisse return PTR_ERR(hmm_device_class); 1576858b54daSJérôme Glisse } 1577858b54daSJérôme Glisse return 0; 1578858b54daSJérôme Glisse } 1579858b54daSJérôme Glisse 1580858b54daSJérôme Glisse device_initcall(hmm_init); 1581df6ad698SJérôme Glisse #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ 1582