diff options
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/nouveau/nouveau_drm.c | 3 | ||||
| -rw-r--r-- | include/linux/hmm.h | 12 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 6 | ||||
| -rw-r--r-- | kernel/fork.c | 1 | ||||
| -rw-r--r-- | mm/hmm.c | 121 |
6 files changed, 34 insertions, 111 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index f2e8b4238efd..abc233088201 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -35,6 +35,7 @@ #include <linux/pm_runtime.h> #include <linux/vga_switcheroo.h> #include <drm/drm_probe_helper.h> +#include <linux/mmu_notifier.h> #include "amdgpu.h" #include "amdgpu_irq.h" @@ -1464,6 +1465,7 @@ static void __exit amdgpu_exit(void) amdgpu_unregister_atpx_handler(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + mmu_notifier_synchronize(); } module_init(amdgpu_init); diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index 7c2fcaba42d6..a0e48a482452 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -28,6 +28,7 @@ #include <linux/pci.h> #include <linux/pm_runtime.h> #include <linux/vga_switcheroo.h> +#include <linux/mmu_notifier.h> #include <drm/drmP.h> #include <drm/drm_crtc_helper.h> @@ -1292,6 +1293,8 @@ nouveau_drm_exit(void) #ifdef CONFIG_NOUVEAU_PLATFORM_DRIVER platform_driver_unregister(&nouveau_platform_driver); #endif + if (IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM)) + mmu_notifier_synchronize(); } module_init(nouveau_drm_init); diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 51e18fbb8953..3fec513b9c00 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -84,15 +84,12 @@ * @notifiers: count of active mmu notifiers */ struct hmm { - struct mm_struct *mm; - struct kref kref; + struct mmu_notifier mmu_notifier; spinlock_t ranges_lock; struct list_head ranges; struct list_head mirrors; - struct mmu_notifier mmu_notifier; struct rw_semaphore mirrors_sem; wait_queue_head_t wq; - struct rcu_head rcu; long notifiers; }; @@ -409,13 +406,6 @@ long hmm_range_dma_unmap(struct hmm_range *range, */ #define HMM_RANGE_DEFAULT_TIMEOUT 1000 -/* Below are for HMM internal use only! Not to be used by device driver! */ -static inline void hmm_mm_init(struct mm_struct *mm) -{ - mm->hmm = NULL; -} -#else /* IS_ENABLED(CONFIG_HMM_MIRROR) */ -static inline void hmm_mm_init(struct mm_struct *mm) {} #endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */ #endif /* LINUX_HMM_H */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3a37a89eb7a7..525d25d93330 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -25,7 +25,6 @@ struct address_space; struct mem_cgroup; -struct hmm; /* * Each physical page in the system has a struct page associated with @@ -502,11 +501,6 @@ struct mm_struct { atomic_long_t hugetlb_usage; #endif struct work_struct async_put_work; - -#ifdef CONFIG_HMM_MIRROR - /* HMM needs to track a few things per mm */ - struct hmm *hmm; -#endif } __randomize_layout; /* diff --git a/kernel/fork.c b/kernel/fork.c index d8ae0f1b4148..bd4a0762f12f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1007,7 +1007,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_owner(mm, p); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_mm_init(mm); - hmm_mm_init(mm); init_tlb_flush_pending(mm); #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS mm->pmd_huge_pte = NULL; @@ -26,101 +26,37 @@ #include <linux/mmu_notifier.h> #include <linux/memory_hotplug.h> -static const struct mmu_notifier_ops hmm_mmu_notifier_ops; - -/** - * hmm_get_or_create - register HMM against an mm (HMM internal) - * - * @mm: mm struct to attach to - * Return: an HMM object, either by referencing the existing - * (per-process) object, or by creating a new one. - * - * This is not intended to be used directly by device drivers. If mm already - * has an HMM struct then it get a reference on it and returns it. Otherwise - * it allocates an HMM struct, initializes it, associate it with the mm and - * returns it. - */ -static struct hmm *hmm_get_or_create(struct mm_struct *mm) +static struct mmu_notifier *hmm_alloc_notifier(struct mm_struct *mm) { struct hmm *hmm; - lockdep_assert_held_write(&mm->mmap_sem); - - /* Abuse the page_table_lock to also protect mm->hmm. */ - spin_lock(&mm->page_table_lock); - hmm = mm->hmm; - if (mm->hmm && kref_get_unless_zero(&mm->hmm->kref)) - goto out_unlock; - spin_unlock(&mm->page_table_lock); - - hmm = kmalloc(sizeof(*hmm), GFP_KERNEL); + hmm = kzalloc(sizeof(*hmm), GFP_KERNEL); if (!hmm) - return NULL; + return ERR_PTR(-ENOMEM); + init_waitqueue_head(&hmm->wq); INIT_LIST_HEAD(&hmm->mirrors); init_rwsem(&hmm->mirrors_sem); - hmm->mmu_notifier.ops = NULL; INIT_LIST_HEAD(&hmm->ranges); spin_lock_init(&hmm->ranges_lock); - kref_init(&hmm->kref); hmm->notifiers = 0; - hmm->mm = mm; - - hmm->mmu_notifier.ops = &hmm_mmu_notifier_ops; - if (__mmu_notifier_register(&hmm->mmu_notifier, mm)) { - kfree(hmm); - return NULL; - } - - mmgrab(hmm->mm); - - /* - * We hold the exclusive mmap_sem here so we know that mm->hmm is - * still NULL or 0 kref, and is safe to update. - */ - spin_lock(&mm->page_table_lock); - mm->hmm = hmm; - -out_unlock: - spin_unlock(&mm->page_table_lock); - return hmm; + return &hmm->mmu_notifier; } -static void hmm_free_rcu(struct rcu_head *rcu) +static void hmm_free_notifier(struct mmu_notifier *mn) { - struct hmm *hmm = container_of(rcu, struct hmm, rcu); + struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); - mmdrop(hmm->mm); + WARN_ON(!list_empty(&hmm->ranges)); + WARN_ON(!list_empty(&hmm->mirrors)); kfree(hmm); } -static void hmm_free(struct kref *kref) -{ - struct hmm *hmm = container_of(kref, struct hmm, kref); - - spin_lock(&hmm->mm->page_table_lock); - if (hmm->mm->hmm == hmm) - hmm->mm->hmm = NULL; - spin_unlock(&hmm->mm->page_table_lock); - - mmu_notifier_unregister_no_release(&hmm->mmu_notifier, hmm->mm); - mmu_notifier_call_srcu(&hmm->rcu, hmm_free_rcu); -} - -static inline void hmm_put(struct hmm *hmm) -{ - kref_put(&hmm->kref, hmm_free); -} - static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) { struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); struct hmm_mirror *mirror; - /* Bail out if hmm is in the process of being freed */ - if (!kref_get_unless_zero(&hmm->kref)) - return; - /* * Since hmm_range_register() holds the mmget() lock hmm_release() is * prevented as long as a range exists. @@ -137,8 +73,6 @@ static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) mirror->ops->release(mirror); } up_read(&hmm->mirrors_sem); - - hmm_put(hmm); } static void notifiers_decrement(struct hmm *hmm) @@ -169,9 +103,6 @@ static int hmm_invalidate_range_start(struct mmu_notifier *mn, unsigned long flags; int ret = 0; - if (!kref_get_unless_zero(&hmm->kref)) - return 0; - spin_lock_irqsave(&hmm->ranges_lock, flags); hmm->notifiers++; list_for_each_entry(range, &hmm->ranges, list) { @@ -206,7 +137,6 @@ static int hmm_invalidate_range_start(struct mmu_notifier *mn, out: if (ret) notifiers_decrement(hmm); - hmm_put(hmm); return ret; } @@ -215,17 +145,15 @@ static void hmm_invalidate_range_end(struct mmu_notifier *mn, { struct hmm *hmm = container_of(mn, struct hmm, mmu_notifier); - if (!kref_get_unless_zero(&hmm->kref)) - return; - notifiers_decrement(hmm); - hmm_put(hmm); } static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { .release = hmm_release, .invalidate_range_start = hmm_invalidate_range_start, .invalidate_range_end = hmm_invalidate_range_end, + .alloc_notifier = hmm_alloc_notifier, + .free_notifier = hmm_free_notifier, }; /* @@ -237,18 +165,27 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { * * To start mirroring a process address space, the device driver must register * an HMM mirror struct. + * + * The caller cannot unregister the hmm_mirror while any ranges are + * registered. + * + * Callers using this function must put a call to mmu_notifier_synchronize() + * in their module exit functions. */ int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm) { + struct mmu_notifier *mn; + lockdep_assert_held_write(&mm->mmap_sem); /* Sanity check */ if (!mm || !mirror || !mirror->ops) return -EINVAL; - mirror->hmm = hmm_get_or_create(mm); - if (!mirror->hmm) - return -ENOMEM; + mn = mmu_notifier_get_locked(&hmm_mmu_notifier_ops, mm); + if (IS_ERR(mn)) + return PTR_ERR(mn); + mirror->hmm = container_of(mn, struct hmm, mmu_notifier); down_write(&mirror->hmm->mirrors_sem); list_add(&mirror->list, &mirror->hmm->mirrors); @@ -272,7 +209,7 @@ void hmm_mirror_unregister(struct hmm_mirror *mirror) down_write(&hmm->mirrors_sem); list_del(&mirror->list); up_write(&hmm->mirrors_sem); - hmm_put(hmm); + mmu_notifier_put(&hmm->mmu_notifier); } EXPORT_SYMBOL(hmm_mirror_unregister); @@ -854,14 +791,13 @@ int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror) return -EINVAL; /* Prevent hmm_release() from running while the range is valid */ - if (!mmget_not_zero(hmm->mm)) + if (!mmget_not_zero(hmm->mmu_notifier.mm)) return -EFAULT; /* Initialize range to track CPU page table updates. */ spin_lock_irqsave(&hmm->ranges_lock, flags); range->hmm = hmm; - kref_get(&hmm->kref); list_add(&range->list, &hmm->ranges); /* @@ -893,8 +829,7 @@ void hmm_range_unregister(struct hmm_range *range) spin_unlock_irqrestore(&hmm->ranges_lock, flags); /* Drop reference taken by hmm_range_register() */ - mmput(hmm->mm); - hmm_put(hmm); + mmput(hmm->mmu_notifier.mm); /* * The range is now invalid and the ref on the hmm is dropped, so @@ -944,14 +879,14 @@ long hmm_range_fault(struct hmm_range *range, unsigned int flags) struct mm_walk mm_walk; int ret; - lockdep_assert_held(&hmm->mm->mmap_sem); + lockdep_assert_held(&hmm->mmu_notifier.mm->mmap_sem); do { /* If range is no longer valid force retry. */ if (!range->valid) return -EBUSY; - vma = find_vma(hmm->mm, start); + vma = find_vma(hmm->mmu_notifier.mm, start); if (vma == NULL || (vma->vm_flags & device_vma)) return -EFAULT; |