+ mm-generalize-the-pgmap-based-page_free-infrastructure.patch added to -mm tree

+ mm-generalize-the-pgmap-based-page_free-infrastructure.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm: generalize the pgmap based page_free infrastructure
has been added to the -mm tree.  Its filename is
     mm-generalize-the-pgmap-based-page_free-infrastructure.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-generalize-the-pgmap-based-page_free-infrastructure.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-generalize-the-pgmap-based-page_free-infrastructure.patch

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm: generalize the pgmap based page_free infrastructure

Key off on the existence of ->page_free to prepare for adding support for
more pgmap types that are device managed and thus need the free callback.

Link: https://lkml.kernel.org/r/20220210072828.2930359-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com>

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Alistair Popple <apopple@nvidia.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: Felix Kuehling <Felix.Kuehling@amd.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/mm/memremap.c~mm-generalize-the-pgmap-based-page_free-infrastructure
+++ a/mm/memremap.c
@@ -473,7 +473,7 @@ EXPORT_SYMBOL_GPL(get_dev_pagemap);
 
 void free_zone_device_page(struct page *page)
 {
-	if (WARN_ON_ONCE(!is_device_private_page(page)))
+	if (WARN_ON_ONCE(!page->pgmap->ops || !page->pgmap->ops->page_free))
 		return;
 
 	__ClearPageWaiters(page);
@@ -481,7 +481,7 @@ void free_zone_device_page(struct page *
 	mem_cgroup_uncharge(page_folio(page));
 
 	/*
-	 * When a device_private page is freed, the page->mapping field
+	 * When a device managed page is freed, the page->mapping field
 	 * may still contain a (stale) mapping value. For example, the
 	 * lower bits of page->mapping may still identify the page as an
 	 * anonymous page. Ultimately, this entire field is just stale
_

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