+ mm-add-device-coherent-vma-selection-for-memory-migration.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: add device coherent vma selection for memory migration
has been added to the -mm tree.  Its filename is
     mm-add-device-coherent-vma-selection-for-memory-migration.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-add-device-coherent-vma-selection-for-memory-migration.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-add-device-coherent-vma-selection-for-memory-migration.patch

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm: add device coherent vma selection for memory migration


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.

Link: https://lkml.kernel.org/r/20220210072828.2930359-17-hch@lst.de
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alistair Poppple <apopple@nvidia.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/include/linux/migrate.h~mm-add-device-coherent-vma-selection-for-memory-migration
+++ a/include/linux/migrate.h
@@ -130,6 +130,7 @@ static inline unsigned long migrate_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 {
--- a/mm/migrate_device.c~mm-add-device-coherent-vma-selection-for-memory-migration
+++ a/mm/migrate_device.c
@@ -147,15 +147,21 @@ again:
 			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;
 		}
_

Patches currently in -mm which might be from hch@lst.de are

mm-unexport-page_init_poison.patch
mm-remove-a-pointless-config_zone_device-check-in-memremap_pages.patch
mm-remove-the-__kernel__-guard-from-linux-mmh.patch
mm-remove-pointless-includes-from-linux-hmmh.patch
mm-move-free_devmap_managed_page-to-memremapc.patch
mm-simplify-freeing-of-devmap-managed-pages.patch
mm-dont-include-linux-memremaph-in-linux-mmh.patch
mm-remove-the-extra-zone_device-struct-page-refcount.patch
fsdax-depend-on-zone_device-fs_dax_limited.patch
mm-generalize-the-pgmap-based-page_free-infrastructure.patch
mm-refactor-check_and_migrate_movable_pages.patch
mm-refactor-the-zone_device-handling-in-migrate_vma_insert_page.patch
mm-refactor-the-zone_device-handling-in-migrate_vma_pages.patch
mm-move-the-migrate_vma_-device-migration-code-into-its-own-file.patch
mm-build-migrate_vma_-for-all-configs-with-zone_device-support.patch
mm-add-zone-device-coherent-type-memory-support.patch
mm-add-device-coherent-vma-selection-for-memory-migration.patch