From: David Hildenbrand david@redhat.com
[ Upstream commit 3c9c797534364593b73ba6ab060a014af8934721 ]
It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY) only on the first level in the resource tree. However, this is no longer holds for driver-managed system RAM (i.e., added via dax/kmem and virtio-mem), which gets added on lower levels, for example, inside device containers.
IORESOURCE_SYSTEM_RAM is defined as IORESOURCE_MEM | IORESOURCE_SYSRAM and just a special type of IORESOURCE_MEM.
The function walk_mem_res() only considers 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 IORESOURCE_MEM | IORESOURCE_BUSY resources, making the function behave similar to walk_system_ram_res().
Link: https://lkml.kernel.org/r/20210325115326.7826-3-david@redhat.com Fixes: ebf71552bb0e ("virtio-mem: Add parent resource for all added "System RAM"") Fixes: c221c0b0308f ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Dan Williams dan.j.williams@intel.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Dan Williams dan.j.williams@intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: Mauro Carvalho Chehab mchehab+huawei@kernel.org Cc: Dave Young dyoung@redhat.com Cc: Baoquan He bhe@redhat.com Cc: Vivek Goyal vgoyal@redhat.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Keith Busch keith.busch@intel.com Cc: Michal Hocko mhocko@suse.com Cc: Qian Cai cai@lca.pw Cc: Oscar Salvador osalvador@suse.de Cc: Eric Biederman ebiederm@xmission.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: "H. Peter Anvin" hpa@zytor.com Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Brijesh Singh brijesh.singh@amd.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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); }