Right now, ZONE_DEVICE memory is always set PG_reserved. We want to
change that.
We could explicitly check for is_zone_device_page(page). But looking at
the pfn_valid() check, it seems safer to just use pfn_to_online_page()
here, that will skip all ZONE_DEVICE pages right away.
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
arch/x86/mm/ioremap.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index a39dcdb5ae34..db6913b48edf 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -77,10 +77,17 @@ static unsigned int __ioremap_check_ram(struct resource *res)
start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
stop_pfn = (res->end + 1) >> PAGE_SHIFT;
if (stop_pfn > start_pfn) {
- for (i = 0; i < (stop_pfn - start_pfn); ++i)
- if (pfn_valid(start_pfn + i) &&
- !PageReserved(pfn_to_page(start_pfn + i)))
+ for (i = 0; i < (stop_pfn - start_pfn); ++i) {
+ struct page *page;
+ /*
+ * We treat any pages that are not online (not managed
+ * by the buddy) as not being RAM. This includes
+ * ZONE_DEVICE pages.
+ */
+ page = pfn_to_online_page(start_pfn + i);
+ if (page && !PageReserved(page))
return IORES_MAP_SYSTEM_RAM;
+ }
}
return 0;
--
2.21.0
