mm: add folio_mc_copy()

Add a #MC variant of folio_copy() which uses copy_mc_highpage() to support
#MC handled during folio copy, it will be used in folio migration soon.

Link: https://lkml.kernel.org/r/20240626085328.608006-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index e2140ea6ae98221093f8d3034360c146bc99b735..a2e3ebead4105821175d1ab37b778931e40b4aff 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1291,6 +1291,7 @@ void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
 void folio_copy(struct folio *dst, struct folio *src);
+int folio_mc_copy(struct folio *dst, struct folio *src);
 
 unsigned long nr_free_buffer_pages(void);
 

diff --git a/mm/util.c b/mm/util.c
index fe723241b66f73d89fd7e9ed618dabe727708824..172213f27c31bee28e8eaa6c63b92d0fda571cca 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -828,6 +828,23 @@ void folio_copy(struct folio *dst, struct folio *src)
 }
 EXPORT_SYMBOL(folio_copy);
 
+int folio_mc_copy(struct folio *dst, struct folio *src)
+{
+       long nr = folio_nr_pages(src);
+       long i = 0;
+
+       for (;;) {
+               if (copy_mc_highpage(folio_page(dst, i), folio_page(src, i)))
+                       return -EHWPOISON;
+               if (++i == nr)
+                       break;
+               cond_resched();
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(folio_mc_copy);
+
 int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS;
 int sysctl_overcommit_ratio __read_mostly = 50;
 unsigned long sysctl_overcommit_kbytes __read_mostly;