It used to be true that we can have system RAM only on the first level in the resourc tree. However, this is no longer holds for driver-managed system RAM (i.e., dax/kmem and virtio-mem).
The function walk_mem_res() only consideres the first level and is used in arch/x86/mm/ioremap.c:__ioremap_check_mem() only. We currently fail to identify System RAM added by dax/kmem and virtio-mem as "IORES_MAP_SYSTEM_RAM", for example, allowing for remapping of such "normal RAM" in __ioremap_caller(). Let's find all busy IORESOURCE_MEM resources, making the function behave similar to walk_system_ram_res(). Cc: Andrew Morton <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Dan Williams <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Mauro Carvalho Chehab <[email protected]> Cc: Signed-off-by: David Hildenbrand <[email protected]> Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Keith Busch <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Qian Cai <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Eric Biederman <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Brijesh Singh <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: David Hildenbrand <[email protected]> --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/resource.c b/kernel/resource.c index 4efd6e912279..16e0c7e8ed24 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -470,7 +470,7 @@ int walk_mem_res(u64 start, u64 end, void *arg, { unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; - return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true, + return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false, arg, func); } -- 2.29.2
