The patch titled
Subject: kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources
has been added to the -mm tree. Its filename is
kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources.patch
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources
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@xxxxxxxxxx
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@xxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/resource.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/resource.c~kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources
+++ a/kernel/resource.c
@@ -470,7 +470,7 @@ int walk_mem_res(u64 start, u64 end, voi
{
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);
}
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-page_alloc-drop-pr_info_ratelimited-in-alloc_contig_range.patch
kernel-resource-make-walk_system_ram_res-find-all-busy-ioresource_system_ram-resources.patch
kernel-resource-make-walk_mem_res-find-all-busy-ioresource_mem-resources.patch
kernel-resource-remove-first_lvl-siblings_only-logic.patch
drivers-char-remove-dev-kmem-for-good.patch
mm-remove-xlate_dev_kmem_ptr.patch
mm-vmalloc-remove-vwrite.patch
