Commit 2b539aef authored Feb 25, 2019 by Dave Hansen Committed by Dan Williams Feb 28, 2019

mm/resource: Let walk_system_ram_range() search child resources



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>

parent 2794129e

kernel/resource.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -454,6 +454,9 @@ int walk_mem_res(u64 start, u64 end, void *arg,
		* 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 *))
		@@ -469,7 +472,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
		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)

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