diff options
Diffstat (limited to 'mm/hmm.c')
| -rw-r--r-- | mm/hmm.c | 170 |
1 files changed, 170 insertions, 0 deletions
@@ -53,6 +53,10 @@ static int hmm_mirror_migrate_back(struct hmm_mirror *mirror, dma_addr_t *dst, unsigned long start, unsigned long end); +static int hmm_mirror_migrate(struct hmm_mirror *mirror, + struct hmm_event *event, + struct vm_area_struct *vma, + struct hmm_pt_iter *iter); static inline int hmm_mirror_update(struct hmm_mirror *mirror, struct hmm_event *event, struct page *page); @@ -101,6 +105,12 @@ static inline int hmm_event_init(struct hmm_event *event, return 0; } +static inline unsigned long hmm_event_npages(const struct hmm_event *event) +{ + return (PAGE_ALIGN(event->end) - (event->start & PAGE_MASK)) >> + PAGE_SHIFT; +} + /* hmm - core HMM functions. * @@ -1180,6 +1190,9 @@ retry: } switch (event->etype) { + case HMM_COPY_TO_DEVICE: + ret = hmm_mirror_migrate(mirror, event, vma, &iter); + break; case HMM_DEVICE_RFAULT: case HMM_DEVICE_WFAULT: ret = hmm_mirror_handle_fault(mirror, event, vma, &iter); @@ -1307,6 +1320,163 @@ static int hmm_mirror_migrate_back(struct hmm_mirror *mirror, return ret ? ret : r; } +static int hmm_mirror_migrate(struct hmm_mirror *mirror, + struct hmm_event *event, + struct vm_area_struct *vma, + struct hmm_pt_iter *iter) +{ + struct hmm_device *device = mirror->device; + struct hmm *hmm = mirror->hmm; + struct hmm_event invalidate; + unsigned long addr, npages; + struct hmm_mirror *tmp; + dma_addr_t *dst; + pte_t *save_pte; + int r = 0, ret; + + /* Only allow migration of private anonymous memory. */ + if (vma->vm_ops || unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) + return -EINVAL; + + /* + * TODO More advance loop for splitting migration into several chunk. + * For now limit the amount that can be migrated in one shot. Also we + * would need to see if we need rescheduling if this is happening as + * part of system call to the device driver. + */ + npages = hmm_event_npages(event); + if (npages * max(sizeof(*dst), sizeof(*save_pte)) > PAGE_SIZE) + return -EINVAL; + dst = kcalloc(npages, sizeof(*dst), GFP_KERNEL); + if (dst == NULL) + return -ENOMEM; + save_pte = kcalloc(npages, sizeof(*save_pte), GFP_KERNEL); + if (save_pte == NULL) { + ret = -ENOMEM; + goto out; + } + + ret = mm_hmm_migrate(hmm->mm, vma, save_pte, &event->backoff, + &hmm->mmu_notifier, event->start, event->end); + if (ret == -EAGAIN) + goto out; + if (ret) + goto out; + + /* + * Now invalidate for all other device, note that they can not race + * with us as the CPU page table is full of special entry. + */ + hmm_event_init(&invalidate, mirror->hmm, event->start, + event->end, HMM_MIGRATE); +again: + down_read(&hmm->rwsem); + hlist_for_each_entry(tmp, &hmm->mirrors, mlist) { + if (tmp == mirror) + continue; + if (hmm_mirror_update(tmp, &invalidate, NULL)) { + hmm_mirror_ref(tmp); + up_read(&hmm->rwsem); + hmm_mirror_kill(tmp); + hmm_mirror_unref(&tmp); + goto again; + } + } + up_read(&hmm->rwsem); + + /* + * Populate the mirror page table with saved entry and also mark entry + * that can be migrated. + */ + for (addr = event->start; addr < event->end;) { + unsigned long i, idx, next = event->end, npages; + dma_addr_t *hmm_pte; + + hmm_pte = hmm_pt_iter_populate(iter, addr, &next); + if (!hmm_pte) { + ret = -ENOMEM; + goto out_cleanup; + } + + npages = (next - addr) >> PAGE_SHIFT; + idx = (addr - event->start) >> PAGE_SHIFT; + hmm_pt_iter_directory_lock(iter); + for (i = 0; i < npages; i++, idx++) { + hmm_pte_clear_select(&hmm_pte[i]); + if (!pte_present(save_pte[idx])) + continue; + hmm_pte_set_select(&hmm_pte[i]); + /* This can not be a valid device entry here. */ + VM_BUG_ON(hmm_pte_test_valid_dev(&hmm_pte[i])); + if (hmm_pte_test_valid_dma(&hmm_pte[i])) + continue; + + if (hmm_pte_test_valid_pfn(&hmm_pte[i])) + continue; + + hmm_pt_iter_directory_ref(iter); + hmm_pte[i] = hmm_pte_from_pfn(pte_pfn(save_pte[idx])); + if (pte_write(save_pte[idx])) + hmm_pte_set_write(&hmm_pte[i]); + hmm_pte_set_select(&hmm_pte[i]); + } + hmm_pt_iter_directory_unlock(iter); + + if (device->dev) { + spinlock_t *lock; + + lock = hmm_pt_iter_directory_lock_ptr(iter); + ret = hmm_mirror_dma_map_range(mirror, hmm_pte, + lock, npages); + /* Keep going only for entry that have been mapped. */ + if (ret) { + for (i = 0; i < npages; ++i) { + if (!hmm_pte_test_select(&dst[i])) + continue; + if (hmm_pte_test_valid_dma(&dst[i])) + continue; + hmm_pte_clear_select(&hmm_pte[i]); + } + } + } + addr = next; + } + + /* Now Waldo we can do the copy. */ + r = device->ops->copy_to_device(mirror, event, vma, dst, + event->start, event->end); + + /* Update mirror page table with successfully migrated entry. */ + for (addr = event->start; addr < event->end;) { + unsigned long i, idx, next = event->end, npages; + dma_addr_t *hmm_pte; + + hmm_pte = hmm_pt_iter_walk(iter, &addr, &next); + if (!hmm_pte) + continue; + npages = (next - addr) >> PAGE_SHIFT; + idx = (addr - event->start) >> PAGE_SHIFT; + hmm_pt_iter_directory_lock(iter); + for (i = 0; i < npages; i++, idx++) { + if (!hmm_pte_test_valid_dev(&dst[idx])) + continue; + + VM_BUG_ON(!hmm_pte_test_select(&hmm_pte[i])); + hmm_pte[i] = dst[idx]; + } + hmm_pt_iter_directory_unlock(iter); + addr = next; + } + +out_cleanup: + mm_hmm_migrate_cleanup(hmm->mm, vma, save_pte, dst, + event->start, event->end); +out: + kfree(save_pte); + kfree(dst); + return ret ? ret : r; +} + /* hmm_mirror_range_discard() - discard a range of address. * * @mirror: The mirror struct. |