From: Alex Sierra <alex.sie...@amd.com> This case is used to migrate pages from device memory, back to system memory. Device coherent type memory is cache coherent from device and CPU point of view.
Signed-off-by: Alex Sierra <alex.sie...@amd.com> Acked-by: Felix Kuehling <felix.kuehl...@amd.com> Reviewed-by: Alistair Poppple <apop...@nvidia.com> Signed-off-by: Christoph Hellwig <h...@lst.de> --- include/linux/migrate.h | 1 + mm/migrate_device.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/migrate.h b/include/linux/migrate.h index db96e10eb8da22..66a34eae8cb635 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -130,6 +130,7 @@ static inline unsigned long migrate_pfn(unsigned long pfn) enum migrate_vma_direction { MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, + MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2, }; struct migrate_vma { diff --git a/mm/migrate_device.c b/mm/migrate_device.c index bfd66e7d830b02..0b295594e7626d 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -147,15 +147,21 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, if (is_writable_device_private_entry(entry)) mpfn |= MIGRATE_PFN_WRITE; } else { - if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) - goto next; pfn = pte_pfn(pte); - if (is_zero_pfn(pfn)) { + if (is_zero_pfn(pfn) && + (migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) { mpfn = MIGRATE_PFN_MIGRATE; migrate->cpages++; goto next; } page = vm_normal_page(migrate->vma, addr, pte); + if (page && !is_zone_device_page(page) && + !(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) + goto next; + else if (page && is_device_coherent_page(page) && + (!(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_COHERENT) || + page->pgmap->owner != migrate->pgmap_owner)) + goto next; mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE; mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0; } -- 2.30.2