From: Matthew Brost <[email protected]> cpages returned from migrate_vma_setup represents the total number of individual pages found, not the number of 4K pages. The math in drm_pagemap_migrate_to_devmem for npages is based on the number of 4K pages, so cpages != npages can fail even if the entire memory range is found in migrate_vma_setup (e.g., when a single 2M page is found). Add drm_pagemap_cpages, which converts cpages to the number of 4K pages found.
Cc: Andrew Morton <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Liam R. Howlett <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Zi Yan <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Balbir Singh <[email protected]> Cc: [email protected] Signed-off-by: Matthew Brost <[email protected]> Reviewed-by: Francois Dugast <[email protected]> Signed-off-by: Francois Dugast <[email protected]> --- drivers/gpu/drm/drm_pagemap.c | 38 ++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c index 61c6ca59df81..801da343f0a6 100644 --- a/drivers/gpu/drm/drm_pagemap.c +++ b/drivers/gpu/drm/drm_pagemap.c @@ -452,6 +452,41 @@ static int drm_pagemap_migrate_range(struct drm_pagemap_devmem *devmem, return ret; } +/** + * drm_pagemap_cpages() - Count collected pages + * @migrate_pfn: Array of migrate_pfn entries to account + * @npages: Number of entries in @migrate_pfn + * + * Compute the total number of minimum-sized pages represented by the + * collected entries in @migrate_pfn. The total is derived from the + * order encoded in each entry. + * + * Return: Total number of minimum-sized pages. + */ +static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages) +{ + unsigned long i, cpages = 0; + + for (i = 0; i < npages;) { + struct page *page = migrate_pfn_to_page(migrate_pfn[i]); + struct folio *folio; + unsigned int order = 0; + + if (page) { + folio = page_folio(page); + order = folio_order(folio); + cpages += NR_PAGES(order); + } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) { + order = HPAGE_PMD_ORDER; + cpages += NR_PAGES(order); + } + + i += NR_PAGES(order); + } + + return cpages; +} + /** * drm_pagemap_migrate_to_devmem() - Migrate a struct mm_struct range to device memory * @devmem_allocation: The device memory allocation to migrate to. @@ -564,7 +599,8 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation, goto err_free; } - if (migrate.cpages != npages) { + if (migrate.cpages != npages && + drm_pagemap_cpages(migrate.src, npages) != npages) { /* * Some pages to migrate. But we want to migrate all or * nothing. Raced or unknown device pages. -- 2.43.0
