drivers/base/node: consolidate node device subsystem initialization in node_dev_init()

...  and call node_dev_init() after memory_dev_init() from driver_init(),
so before any of the existing arch/subsys calls.  All online nodes should
be known at that point: early during boot, arch code determines node and
zone ranges and sets the relevant nodes online; usually this happens in
setup_arch().

This is in line with memory_dev_init(), which initializes the memory
device subsystem and creates all memory block devices.

Similar to memory_dev_init(), panic() if anything goes wrong, we don't
want to continue with such basic initialization errors.

The important part is that node_dev_init() gets called after
memory_dev_init() and after cpu_dev_init(), but before any of the relevant
archs call register_cpu() to register the new cpu device under the node
device.  The latter should be the case for the current users of
topology_init().

Link: https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Anatoly Pugachev <matorola@gmail.com> (sparc64)
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/node.h b/include/linux/node.h
index 81bbf1c0afd3..7f876d48af11 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -112,6 +112,7 @@ static inline void link_mem_sections(int nid, unsigned long start_pfn,
 
 extern void unregister_node(struct node *node);
 #ifdef CONFIG_NUMA
+extern void node_dev_init(void);
 /* Core of the node registration - only memory hotplug should use this */
 extern int __register_one_node(int nid);
 
@@ -149,6 +150,9 @@ extern void register_hugetlbfs_with_node(node_registration_func_t doregister,
 					 node_registration_func_t unregister);
 #endif
 #else
+static inline void node_dev_init(void)
+{
+}
 static inline int __register_one_node(int nid)
 {
 	return 0;