diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c index 6aa745682270..a0546955d0b9 100644 --- a/drivers/gpu/drm/drm_pagemap.c +++ b/drivers/gpu/drm/drm_pagemap.c @@ -383,6 +383,58 @@ drm_pagemap_migrate_map_system_pages(struct device *dev, return 0; } +/** + * drm_pagemap_migrate_populate_src_pages() - Populate the source page array + * @pages: Array of source pages to populate + * @src_mpfn: Source array of migrate PFNs + * @dst_mpfn: Destination array of migrate PFNs + * @npages: Number of pages in the arrays + * + * Populate @pages with the device pages the copy callback is to read from. + * + * Entries are normally only populated at the head of each source folio, with + * the copy callback deriving the rest of the folio from the order recorded in + * the corresponding drm_pagemap_addr. That does not work where + * drm_pagemap_migrate_populate_ram_pfn() had to demote a higher-order source + * folio to order-0 destination folios: the drm_pagemap_addr entries are then + * per-page, and the copy callback needs a source page for each of them. + * Populate every entry for those ranges. + * + * Note that the source folio itself is only split later, by + * migrate_vma_pages() / migrate_device_pages(), so its order cannot be used to + * detect the demotion - the destination has to be inspected instead. + */ +static void drm_pagemap_migrate_populate_src_pages(struct page **pages, + unsigned long *src_mpfn, + unsigned long *dst_mpfn, + unsigned long npages) +{ + unsigned long i; + + for (i = 0; i < npages;) { + struct page *page = migrate_pfn_to_page(src_mpfn[i]); + unsigned int order = 0; + unsigned long j, nr; + + if (!page) { + i++; + continue; + } + + order = folio_order(page_folio(page)); + nr = NR_PAGES(order); + + if (order && !(dst_mpfn[i] & MIGRATE_PFN_COMPOUND)) { + for (j = 0; j < nr && i + j < npages; j++) + pages[i + j] = folio_page(page_folio(page), j); + } else { + pages[i] = page; + } + + i += nr; + } +} + /** * drm_pagemap_migrate_unmap_pages() - Unmap pages previously mapped for GPU SVM migration * @dev: The device for which the pages were mapped @@ -875,6 +927,7 @@ static int drm_pagemap_migrate_populate_ram_pfn(struct vm_area_struct *vas, struct page *page = NULL, *src_page; struct folio *folio; unsigned int order = 0; + gfp_t gfp = GFP_HIGHUSER; if (!(src_mpfn[i] & MIGRATE_PFN_MIGRATE)) goto next; @@ -891,11 +944,51 @@ static int drm_pagemap_migrate_populate_ram_pfn(struct vm_area_struct *vas, order = folio_order(page_folio(src_page)); - /* TODO: Support fallback to single pages if THP allocation fails */ + /* + * A large source folio is always collected whole, at its head + * page, PMD aligned and flagged MIGRATE_PFN_COMPOUND: anything + * else is split before it reaches us, either by + * migrate_vma_collect_pmd() or, for the eviction path, by + * migrate_device_pfns(). Both the order-0 fallback below and + * drm_pagemap_migrate_populate_src_pages() rely on that, as + * they index the folio from @i. + */ + WARN_ON_ONCE(order && + (src_page != folio_page(page_folio(src_page), 0) || + !(src_mpfn[i] & MIGRATE_PFN_COMPOUND))); + + if (order) + gfp |= __GFP_NOWARN; + if (vas) - folio = vma_alloc_folio(GFP_HIGHUSER, order, vas, addr); + folio = vma_alloc_folio(gfp, order, vas, addr); else - folio = folio_alloc(GFP_HIGHUSER, order); + folio = folio_alloc(gfp, order); + + if (!folio && order) { + /* + * Higher-order allocation failed, fall back to + * order-0 allocations for the entire range covered + * by the original higher-order allocation, without + * setting MIGRATE_PFN_COMPOUND, until we move past + * that range. + */ + unsigned long nr = NR_PAGES(order); + unsigned long j; + + gfp &= ~__GFP_NOWARN; + for (j = 0; j < nr && i < npages; j++, i++, addr += PAGE_SIZE) { + folio = vas ? + vma_alloc_folio(gfp, 0, vas, addr) : + folio_alloc(gfp, 0); + if (!folio) + goto free_pages; + + page = folio_page(folio, 0); + mpfn[i] = migrate_pfn(page_to_pfn(page)); + } + continue; + } if (!folio) goto free_pages; @@ -940,11 +1033,11 @@ static int drm_pagemap_migrate_populate_ram_pfn(struct vm_area_struct *vas, if (!page) goto next_put; + order = folio_order(page_folio(page)); + put_page(page); mpfn[i] = 0; - order = folio_order(page_folio(page)); - next_put: i += NR_PAGES(order); } @@ -1225,7 +1318,7 @@ int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation) unsigned long *src, *dst; struct drm_pagemap_addr *pagemap_addr; void *buf; - int i, err = 0; + int err = 0; unsigned int retry_count = 2; npages = devmem_allocation->size >> PAGE_SHIFT; @@ -1268,15 +1361,7 @@ int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation) if (err) goto err_finalize; - for (i = 0; i < npages;) { - unsigned int order = 0; - - pages[i] = migrate_pfn_to_page(src[i]); - if (pages[i]) - order = folio_order(page_folio(pages[i])); - - i += NR_PAGES(order); - } + drm_pagemap_migrate_populate_src_pages(pages, src, dst, npages); err = ops->copy_to_ram(pages, pagemap_addr, npages, NULL); if (err) @@ -1344,7 +1429,7 @@ static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas, struct drm_pagemap_addr *pagemap_addr; unsigned long start, end; void *buf; - int i, err = 0; + int err = 0; zdd = drm_pagemap_page_zone_device_data(page); if (time_before64(get_jiffies_64(), zdd->devmem_allocation->timeslice_expiration)) @@ -1401,15 +1486,8 @@ static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas, if (err) goto err_finalize; - for (i = 0; i < npages;) { - unsigned int order = 0; - - pages[i] = migrate_pfn_to_page(migrate.src[i]); - if (pages[i]) - order = folio_order(page_folio(pages[i])); - - i += NR_PAGES(order); - } + drm_pagemap_migrate_populate_src_pages(pages, migrate.src, migrate.dst, + npages); err = ops->copy_to_ram(pages, pagemap_addr, npages, NULL); if (err)