[PATCH v3 6/6] nouveau: support THP migration to private memory

Add support for migrating transparent huge pages to and from device private memory.

Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- drivers/gpu/drm/nouveau/nouveau_dmem.c | 289 ++++++++++++++++++------- drivers/gpu/drm/nouveau/nouveau_svm.c | 11 +- drivers/gpu/drm/nouveau/nouveau_svm.h | 3 +- 3 files changed, 215 insertions(+), 88 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 92987daa5e17..93eea8e9d987 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -82,6 +82,7 @@ struct nouveau_dmem { struct list_head chunks; struct mutex mutex; struct page *free_pages; + struct page *free_huge_pages; spinlock_t lock; };

@@ -112,8 +113,13 @@ static void nouveau_dmem_page_free(struct page *page) struct nouveau_dmem *dmem = chunk->drm->dmem;

spin_lock(&dmem->lock); - page->zone_device_data = dmem->free_pages; - dmem->free_pages = page; + if (PageHead(page)) { + page->zone_device_data = dmem->free_huge_pages; + dmem->free_huge_pages = page; + } else { + page->zone_device_data = dmem->free_pages; + dmem->free_pages = page; + }

WARN_ON(!chunk->callocated); chunk->callocated--; @@ -139,51 +145,100 @@ static void nouveau_dmem_fence_done(struct nouveau_fence **fence)

static vm_fault_t nouveau_dmem_fault_copy_one(struct nouveau_drm *drm, struct vm_fault *vmf, struct migrate_vma *args, - dma_addr_t *dma_addr) + struct page *spage, bool is_huge, dma_addr_t *dma_addr) { + struct nouveau_svmm *svmm = spage->zone_device_data; struct device *dev = drm->dev->dev; - struct page *dpage, *spage; - struct nouveau_svmm *svmm; - - spage = migrate_pfn_to_page(args->src[0]); - if (!spage || !(args->src[0] & MIGRATE_PFN_MIGRATE)) - return 0; + struct page *dpage; + unsigned int i;

- dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address); + if (is_huge) + dpage = alloc_transhugepage(vmf->vma, args->start); + else + dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address); if (!dpage) - return VM_FAULT_SIGBUS; - lock_page(dpage); + return VM_FAULT_OOM; + WARN_ON_ONCE(thp_order(spage) != thp_order(dpage));

- *dma_addr = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL); + *dma_addr = dma_map_page(dev, dpage, 0, page_size(dpage), + DMA_BIDIRECTIONAL); if (dma_mapping_error(dev, *dma_addr)) goto error_free_page;

- svmm = spage->zone_device_data; + lock_page(dpage); + i = (vmf->address - args->start) >> PAGE_SHIFT; + spage += i; mutex_lock(&svmm->mutex); nouveau_svmm_invalidate(svmm, args->start, args->end); - if (drm->dmem->migrate.copy_func(drm, 1, NOUVEAU_APER_HOST, *dma_addr, - NOUVEAU_APER_VRAM, nouveau_dmem_page_addr(spage))) + if (drm->dmem->migrate.copy_func(drm, thp_nr_pages(dpage), + NOUVEAU_APER_HOST, *dma_addr, NOUVEAU_APER_VRAM, + nouveau_dmem_page_addr(spage))) goto error_dma_unmap; mutex_unlock(&svmm->mutex);

- args->dst[0] = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + args->dst[i] = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + if (is_huge) + args->dst[i] |= MIGRATE_PFN_COMPOUND; return 0;

error_dma_unmap: mutex_unlock(&svmm->mutex); - dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL); + unlock_page(dpage); + dma_unmap_page(dev, *dma_addr, page_size(dpage), DMA_BIDIRECTIONAL); error_free_page: __free_page(dpage); return VM_FAULT_SIGBUS; }

+static vm_fault_t nouveau_dmem_fault_chunk(struct nouveau_drm *drm, + struct vm_fault *vmf, struct migrate_vma *args) +{ + struct device *dev = drm->dev->dev; + struct nouveau_fence *fence; + struct page *spage; + unsigned long src = args->src[0]; + bool is_huge = (src & (MIGRATE_PFN_MIGRATE | MIGRATE_PFN_COMPOUND)) == + (MIGRATE_PFN_MIGRATE | MIGRATE_PFN_COMPOUND); + unsigned long dma_page_size; + dma_addr_t dma_addr; + vm_fault_t ret = 0; + + spage = migrate_pfn_to_page(src); + if (!spage) { + ret = VM_FAULT_SIGBUS; + goto out; + } + if (is_huge) { + dma_page_size = PMD_SIZE; + ret = nouveau_dmem_fault_copy_one(drm, vmf, args, spage, true, + &dma_addr); + if (!ret) + goto fence; + /* + * If we couldn't allocate a huge page, fallback to migrating + * a single page. + */ + } + dma_page_size = PAGE_SIZE; + ret = nouveau_dmem_fault_copy_one(drm, vmf, args, spage, false, + &dma_addr); + if (ret) + goto out; +fence: + nouveau_fence_new(drm->dmem->migrate.chan, false, &fence); + migrate_vma_pages(args); + nouveau_dmem_fence_done(&fence); + dma_unmap_page(dev, dma_addr, dma_page_size, DMA_BIDIRECTIONAL); +out: + migrate_vma_finalize(args); + return ret; +} + static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf) { struct nouveau_drm *drm = page_to_drm(vmf->page); - struct nouveau_dmem *dmem = drm->dmem; - struct nouveau_fence *fence; unsigned long src = 0, dst = 0; - dma_addr_t dma_addr = 0; + struct page *page; vm_fault_t ret; struct migrate_vma args = { .vma = vmf->vma, @@ -192,39 +247,64 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf) .src = &src, .dst = &dst, .pgmap_owner = drm->dev, - .flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE, + .flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE | + MIGRATE_VMA_SELECT_COMPOUND, };

+ /* + * If the page was migrated to the GPU as a huge page, try to + * migrate it back the same way. + */ + page = thp_head(vmf->page); + if (PageHead(page)) { + unsigned int order = thp_order(page); + unsigned int nr_pages = 1U << order; + + args.start &= PAGE_MASK << order; + args.end = args.start + (PAGE_SIZE << order); + args.src = kmalloc_array(nr_pages, sizeof(*args.src), + GFP_KERNEL); + if (!args.src) + return VM_FAULT_OOM; + args.dst = kmalloc_array(nr_pages, sizeof(*args.dst), + GFP_KERNEL); + if (!args.dst) { + ret = VM_FAULT_OOM; + goto error_src; + } + } + /* * FIXME what we really want is to find some heuristic to migrate more * than just one page on CPU fault. When such fault happens it is very * likely that more surrounding page will CPU fault too. */ - if (migrate_vma_setup(&args) < 0) - return VM_FAULT_SIGBUS; - if (!args.cpages) - return 0; - - ret = nouveau_dmem_fault_copy_one(drm, vmf, &args, &dma_addr); - if (ret || dst == 0) - goto done; - - nouveau_fence_new(dmem->migrate.chan, false, &fence); - migrate_vma_pages(&args); - nouveau_dmem_fence_done(&fence); - dma_unmap_page(drm->dev->dev, dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL); -done: - migrate_vma_finalize(&args); + if (migrate_vma_setup(&args)) + ret = VM_FAULT_SIGBUS; + else + ret = nouveau_dmem_fault_chunk(drm, vmf, &args); + if (args.dst != &dst) + kfree(args.dst); +error_src: + if (args.src != &src) + kfree(args.src); return ret; }

+static void nouveau_page_split(struct page *head, struct page *page) +{ + page->pgmap = head->pgmap; + page->zone_device_data = head->zone_device_data; +} + static const struct dev_pagemap_ops nouveau_dmem_pagemap_ops = { .page_free = nouveau_dmem_page_free, .migrate_to_ram = nouveau_dmem_migrate_to_ram, + .page_split = nouveau_page_split, };

-static int -nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage) +static int nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, bool is_huge, + struct page **ppage) { struct nouveau_dmem_chunk *chunk; struct resource *res; @@ -278,16 +358,20 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage) pfn_first = chunk->pagemap.range.start >> PAGE_SHIFT; page = pfn_to_page(pfn_first); spin_lock(&drm->dmem->lock); - for (i = 0; i < DMEM_CHUNK_NPAGES - 1; ++i, ++page) { - page->zone_device_data = drm->dmem->free_pages; - drm->dmem->free_pages = page; - } + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && is_huge) + prep_transhuge_device_private_page(page); + else + for (i = 0; i < DMEM_CHUNK_NPAGES - 1; ++i, ++page) { + page->zone_device_data = drm->dmem->free_pages; + drm->dmem->free_pages = page; + } *ppage = page; chunk->callocated++; spin_unlock(&drm->dmem->lock);

- NV_INFO(drm, "DMEM: registered %ldMB of device memory\n", - DMEM_CHUNK_SIZE >> 20); + NV_INFO(drm, "DMEM: registered %ldMB of %sdevice memory %lx %lx\n", + DMEM_CHUNK_SIZE >> 20, is_huge ? "huge " : "", pfn_first, + nouveau_dmem_page_addr(page));

return 0;

@@ -304,14 +388,20 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage) }

static struct page * -nouveau_dmem_page_alloc_locked(struct nouveau_drm *drm) +nouveau_dmem_page_alloc_locked(struct nouveau_drm *drm, bool is_huge) { struct nouveau_dmem_chunk *chunk; struct page *page = NULL; int ret;

spin_lock(&drm->dmem->lock); - if (drm->dmem->free_pages) { + if (is_huge && drm->dmem->free_huge_pages) { + page = drm->dmem->free_huge_pages; + drm->dmem->free_huge_pages = page->zone_device_data; + chunk = nouveau_page_to_chunk(page); + chunk->callocated++; + spin_unlock(&drm->dmem->lock); + } else if (!is_huge && drm->dmem->free_pages) { page = drm->dmem->free_pages; drm->dmem->free_pages = page->zone_device_data; chunk = nouveau_page_to_chunk(page); @@ -319,7 +409,7 @@ nouveau_dmem_page_alloc_locked(struct nouveau_drm *drm) spin_unlock(&drm->dmem->lock); } else { spin_unlock(&drm->dmem->lock); - ret = nouveau_dmem_chunk_alloc(drm, &page); + ret = nouveau_dmem_chunk_alloc(drm, is_huge, &page); if (ret) return NULL; } @@ -567,31 +657,22 @@ nouveau_dmem_init(struct nouveau_drm *drm)

static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, struct nouveau_svmm *svmm, unsigned long src, - dma_addr_t *dma_addr, u64 *pfn) + struct page *spage, bool is_huge, dma_addr_t dma_addr, u64 *pfn) { - struct device *dev = drm->dev->dev; - struct page *dpage, *spage; + struct page *dpage; unsigned long paddr; + unsigned long dst;

- spage = migrate_pfn_to_page(src); - if (!(src & MIGRATE_PFN_MIGRATE)) - goto out; - - dpage = nouveau_dmem_page_alloc_locked(drm); + dpage = nouveau_dmem_page_alloc_locked(drm, is_huge); if (!dpage) goto out;

paddr = nouveau_dmem_page_addr(dpage); if (spage) { - *dma_addr = dma_map_page(dev, spage, 0, page_size(spage), - DMA_BIDIRECTIONAL); - if (dma_mapping_error(dev, *dma_addr)) + if (drm->dmem->migrate.copy_func(drm, thp_nr_pages(dpage), + NOUVEAU_APER_VRAM, paddr, NOUVEAU_APER_HOST, dma_addr)) goto out_free_page; - if (drm->dmem->migrate.copy_func(drm, 1, - NOUVEAU_APER_VRAM, paddr, NOUVEAU_APER_HOST, *dma_addr)) - goto out_dma_unmap; } else { - *dma_addr = DMA_MAPPING_ERROR; if (drm->dmem->migrate.clear_func(drm, page_size(dpage), NOUVEAU_APER_VRAM, paddr)) goto out_free_page; @@ -602,10 +683,11 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, ((paddr >> PAGE_SHIFT) << NVIF_VMM_PFNMAP_V0_ADDR_SHIFT); if (src & MIGRATE_PFN_WRITE) *pfn |= NVIF_VMM_PFNMAP_V0_W; - return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + if (PageHead(dpage)) + dst |= MIGRATE_PFN_COMPOUND; + return dst;

-out_dma_unmap: - dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL); out_free_page: nouveau_dmem_page_free_locked(drm, dpage); out: @@ -617,26 +699,64 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm, struct nouveau_svmm *svmm, struct migrate_vma *args, dma_addr_t *dma_addrs, u64 *pfns) { + struct device *dev = drm->dev->dev; struct nouveau_fence *fence; unsigned long addr = args->start, nr_dma = 0, i; + unsigned int page_shift = PAGE_SHIFT; + struct page *spage; + unsigned long src = args->src[0]; + bool is_huge = (src & (MIGRATE_PFN_MIGRATE | MIGRATE_PFN_COMPOUND)) == + (MIGRATE_PFN_MIGRATE | MIGRATE_PFN_COMPOUND); + unsigned long dma_page_size = is_huge ? PMD_SIZE : PAGE_SIZE; + + if (is_huge) { + spage = migrate_pfn_to_page(src); + if (spage) { + dma_addrs[nr_dma] = dma_map_page(dev, spage, 0, + page_size(spage), + DMA_BIDIRECTIONAL); + if (dma_mapping_error(dev, dma_addrs[nr_dma])) + goto out; + nr_dma++; + } + args->dst[0] = nouveau_dmem_migrate_copy_one(drm, svmm, src, + spage, true, *dma_addrs, pfns); + if (args->dst[0] & MIGRATE_PFN_COMPOUND) { + page_shift = PMD_SHIFT; + i = 1; + goto fence; + } + }

- for (i = 0; addr < args->end; i++) { - args->dst[i] = nouveau_dmem_migrate_copy_one(drm, svmm, - args->src[i], dma_addrs + nr_dma, pfns + i); - if (!dma_mapping_error(drm->dev->dev, dma_addrs[nr_dma])) + for (i = 0; addr < args->end; i++, addr += PAGE_SIZE) { + src = args->src[i]; + if (!(src & MIGRATE_PFN_MIGRATE)) + continue; + spage = migrate_pfn_to_page(src); + if (spage && !is_huge) { + dma_addrs[i] = dma_map_page(dev, spage, 0, + page_size(spage), + DMA_BIDIRECTIONAL); + if (dma_mapping_error(dev, dma_addrs[i])) + break; nr_dma++; - addr += PAGE_SIZE; + } else if (spage && is_huge && i != 0) + dma_addrs[i] = dma_addrs[i - 1] + PAGE_SIZE; + args->dst[i] = nouveau_dmem_migrate_copy_one(drm, svmm, src, + spage, false, dma_addrs[i], pfns + i); }

+fence: nouveau_fence_new(drm->dmem->migrate.chan, false, &fence); migrate_vma_pages(args); nouveau_dmem_fence_done(&fence); - nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, i); + nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, i, + page_shift);

- while (nr_dma--) { - dma_unmap_page(drm->dev->dev, dma_addrs[nr_dma], PAGE_SIZE, - DMA_BIDIRECTIONAL); - } + while (nr_dma) + dma_unmap_page(drm->dev->dev, dma_addrs[--nr_dma], + dma_page_size, DMA_BIDIRECTIONAL); +out: migrate_vma_finalize(args); }

@@ -648,25 +768,25 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, unsigned long end) { unsigned long npages = (end - start) >> PAGE_SHIFT; - unsigned long max = min(SG_MAX_SINGLE_ALLOC, npages); + unsigned long max = min(1UL << (PMD_SHIFT - PAGE_SHIFT), npages); dma_addr_t *dma_addrs; struct migrate_vma args = { .vma = vma, .start = start, .pgmap_owner = drm->dev, - .flags = MIGRATE_VMA_SELECT_SYSTEM, + .flags = MIGRATE_VMA_SELECT_SYSTEM | + MIGRATE_VMA_SELECT_COMPOUND, }; - unsigned long i; u64 *pfns; int ret = -ENOMEM;

if (drm->dmem == NULL) return -ENODEV;

- args.src = kcalloc(max, sizeof(*args.src), GFP_KERNEL); + args.src = kmalloc_array(max, sizeof(*args.src), GFP_KERNEL); if (!args.src) goto out; - args.dst = kcalloc(max, sizeof(*args.dst), GFP_KERNEL); + args.dst = kmalloc_array(max, sizeof(*args.dst), GFP_KERNEL); if (!args.dst) goto out_free_src;

@@ -678,8 +798,10 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, if (!pfns) goto out_free_dma;

- for (i = 0; i < npages; i += max) { - args.end = start + (max << PAGE_SHIFT); + for (; args.start < end; args.start = args.end) { + args.end = min(end, ALIGN(args.start, PMD_SIZE)); + if (args.start == args.end) + args.end = min(end, args.start + PMD_SIZE); ret = migrate_vma_setup(&args); if (ret) goto out_free_pfns; @@ -687,7 +809,6 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, if (args.cpages) nouveau_dmem_migrate_chunk(drm, svmm, &args, dma_addrs, pfns); - args.start = args.end; }

ret = 0; diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 4f69e4c3dafd..3db0997f21b5 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -681,7 +681,6 @@ nouveau_svm_fault(struct nvif_notify *notify) nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]); continue; } - SVMM_DBG(svmm, "addr %016llx", buffer->fault[fi]->addr);

/* We try and group handling of faults within a small * window into a single update. @@ -733,6 +732,10 @@ nouveau_svm_fault(struct nvif_notify *notify) } mmput(mm);

+ SVMM_DBG(svmm, "addr %llx %s %c", buffer->fault[fi]->addr, + args.phys[0] & NVIF_VMM_PFNMAP_V0_VRAM ? + "vram" : "sysmem", + args.i.p.size > PAGE_SIZE ? 'H' : 'N'); limit = args.i.p.addr + args.i.p.size; for (fn = fi; ++fn < buffer->fault_nr; ) { /* It's okay to skip over duplicate addresses from the @@ -804,13 +807,15 @@ nouveau_pfns_free(u64 *pfns)

void nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm, - unsigned long addr, u64 *pfns, unsigned long npages) + unsigned long addr, u64 *pfns, unsigned long npages, + unsigned int page_shift) { struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns); int ret;

args->p.addr = addr; - args->p.size = npages << PAGE_SHIFT; + args->p.page = page_shift; + args->p.size = npages << args->p.page;

mutex_lock(&svmm->mutex);

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.h b/drivers/gpu/drm/nouveau/nouveau_svm.h index e7d63d7f0c2d..3fd78662f17e 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.h +++ b/drivers/gpu/drm/nouveau/nouveau_svm.h @@ -33,7 +33,8 @@ void nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit); u64 *nouveau_pfns_alloc(unsigned long npages); void nouveau_pfns_free(u64 *pfns); void nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm, - unsigned long addr, u64 *pfns, unsigned long npages); + unsigned long addr, u64 *pfns, unsigned long npages, + unsigned int page_shift); #else /* IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) */ static inline void nouveau_svm_init(struct nouveau_drm *drm) {} static inline void nouveau_svm_fini(struct nouveau_drm *drm) {}