mm, memory_hotplug: provide a more generic restrictions for memory hotplug

arch_add_memory, __add_pages take a want_memblock which controls whether
the newly added memory should get the sysfs memblock user API (e.g.
ZONE_DEVICE users do not want/need this interface).  Some callers even
want to control where do we allocate the memmap from by configuring
altmap.

Add a more generic hotplug context for arch_add_memory and __add_pages.
struct mhp_restrictions contains flags which contains additional features
to be enabled by the memory hotplug (MHP_MEMBLOCK_API currently) and
altmap for alternative memmap allocator.

This patch shouldn't introduce any functional change.

[akpm@linux-foundation.org: build fix]
Link: http://lkml.kernel.org/r/20190408082633.2864-3-osalvador@suse.de
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 75f9f6590677..339d5a62d5d5 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -273,12 +273,12 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
  * add the new pages.
  */
 int __ref __add_pages(int nid, unsigned long phys_start_pfn,
-                unsigned long nr_pages, struct vmem_altmap *altmap,
-                bool want_memblock)
+                unsigned long nr_pages, struct mhp_restrictions *restrictions)
 {
         unsigned long i;
         int err = 0;
         int start_sec, end_sec;
+        struct vmem_altmap *altmap = restrictions->altmap;
 
         /* during initialize mem_map, align hot-added range to section */
         start_sec = pfn_to_section_nr(phys_start_pfn);
@@ -299,7 +299,7 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
 
         for (i = start_sec; i <= end_sec; i++) {
                 err = __add_section(nid, section_nr_to_pfn(i), altmap,
-                                want_memblock);
+                                restrictions->flags & MHP_MEMBLOCK_API);
 
                 /*
                  * EEXIST is finally dealt with by ioresource collision
@@ -1097,6 +1097,9 @@ static int online_memory_block(struct memory_block *mem, void *arg)
  */
 int __ref add_memory_resource(int nid, struct resource *res)
 {
+        struct mhp_restrictions restrictions = {
+                .flags = MHP_MEMBLOCK_API,
+        };
         u64 start, size;
         bool new_node = false;
         int ret;
@@ -1124,7 +1127,7 @@ int __ref add_memory_resource(int nid, struct resource *res)
         new_node = ret;
 
         /* call arch's memory hotadd */
-        ret = arch_add_memory(nid, start, size, NULL, true);
+        ret = arch_add_memory(nid, start, size, &restrictions);
         if (ret < 0)
                 goto error;