From 2b539aefe9e48e3908cff02699aa63a8b9bd268e Mon Sep 17 00:00:00 2001
From: Dave Hansen <dave.hansen@linux.intel.com>
Date: Mon, 25 Feb 2019 10:57:38 -0800
Subject: [PATCH] mm/resource: Let walk_system_ram_range() search child
resources
Git-commit: 2b539aefe9e48e3908cff02699aa63a8b9bd268e
Patch-mainline: v5.1-rc1
References: jsc#SLE-5340
mhocko@suse.cz:
we are missing 010a93bf97c72 and co. which restructured the code quite.
I haven't pulled those in as they do not seem to be directly related
and I am not aware of bug reports about issues mentioned in those commits.
jlee@suse.com:
I has backported 010a93bf97c72 for bsc#1181193. So this patch be respin
back to the original code from v5.1-rc1 kernel mainline.
In the process of onlining memory, we use walk_system_ram_range()
to find the actual RAM areas inside of the area being onlined.
However, it currently only finds memory resources which are
"top-level" iomem_resources. Children are not currently
searched which causes it to skip System RAM in areas like this
(in the format of /proc/iomem):
a0000000-bfffffff : Persistent Memory (legacy)
a0000000-afffffff : System RAM
Changing the true->false here allows children to be searched
as well. We need this because we add a new "System RAM"
resource underneath the "persistent memory" resource when
we use persistent memory in a volatile mode.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: linux-nvdimm@lists.01.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Huang Ying <ying.huang@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Joey Lee <jlee@suse.com>
---
kernel/resource.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -479,6 +479,9 @@ int walk_mem_res(u64 start, u64 end, voi
* This function calls the @func callback against all memory ranges of type
* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
* It is to be used only for System RAM.
+ *
+ * This will find System RAM ranges that are children of top-level resources
+ * in addition to top-level System RAM resources.
*/
int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
@@ -494,7 +497,7 @@ int walk_system_ram_range(unsigned long
flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
while (start < end &&
!find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
- true, &res)) {
+ false, &res)) {
pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
end_pfn = (res.end + 1) >> PAGE_SHIFT;
if (end_pfn > pfn)