memblock: allow to specify flags with memblock_add_node()

We want to specify flags when hotplugging memory.  Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.

Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images.  It's important to add the memory
directly to memblock via a single call with the right flags, instead of
adding the memory first and apply flags later: otherwise, concurrent
memblock users might temporarily stumble over memblocks with wrong
flags, which will be important in a follow-up patch that introduces a
new flag to properly handle add_memory_driver_managed().

Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shahab Vahedi <shahab@synopsys.com>	[arch/arc]
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 3 insertions, 2 deletions

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 1d2b3e902a84..8b6560dc7a9e 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -104,7 +104,8 @@ static inline void memblock_discard(void) {}
 #endif
 
 void memblock_allow_resize(void);
-int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
+int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid,
+		      enum memblock_flags flags);
 int memblock_add(phys_addr_t base, phys_addr_t size);
 int memblock_remove(phys_addr_t base, phys_addr_t size);
 int memblock_phys_free(phys_addr_t base, phys_addr_t size);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7e37c726b9db..15058d9cec99 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2425,7 +2425,7 @@ static inline unsigned long get_num_physpages(void)
  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
  * 							 max_highmem_pfn};
  * for_each_valid_physical_page_range()
- * 	memblock_add_node(base, size, nid)
+ *	memblock_add_node(base, size, nid, MEMBLOCK_NONE)
  * free_area_init(max_zone_pfns);
  */
 void free_area_init(unsigned long *max_zone_pfn);