mm/memory_hotplug: embed vmem_altmap details in memory block

With memmap on memory, some architecture needs more details w.r.t altmap
such as base_pfn, end_pfn, etc to unmap vmemmap memory.  Instead of
computing them again when we remove a memory block, embed vmem_altmap
details in struct memory_block if we are using memmap on memory block
feature.

[yangyingliang@huawei.com: fix error return code in add_memory_resource()]
  Link: https://lkml.kernel.org/r/20230809081552.1351184-1-yangyingliang@huawei.com
Link: https://lkml.kernel.org/r/20230808091501.287660-7-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b456ac21361058..8191709c9ad283 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -105,7 +105,8 @@ EXPORT_SYMBOL(unregister_memory_notifier);
 static void memory_block_release(struct device *dev)
 {
 	struct memory_block *mem = to_memory_block(dev);
-
+	/* Verify that the altmap is freed */
+	WARN_ON(mem->altmap);
 	kfree(mem);
 }
 
@@ -183,7 +184,7 @@ static int memory_block_online(struct memory_block *mem)
 {
 	unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
 	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
-	unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
+	unsigned long nr_vmemmap_pages = 0;
 	struct zone *zone;
 	int ret;
 
@@ -200,6 +201,9 @@ static int memory_block_online(struct memory_block *mem)
 	 * stage helps to keep accounting easier to follow - e.g vmemmaps
 	 * belong to the same zone as the memory they backed.
 	 */
+	if (mem->altmap)
+		nr_vmemmap_pages = mem->altmap->free;
+
 	if (nr_vmemmap_pages) {
 		ret = mhp_init_memmap_on_memory(start_pfn, nr_vmemmap_pages, zone);
 		if (ret)
@@ -230,7 +234,7 @@ static int memory_block_offline(struct memory_block *mem)
 {
 	unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
 	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
-	unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
+	unsigned long nr_vmemmap_pages = 0;
 	int ret;
 
 	if (!mem->zone)
@@ -240,6 +244,9 @@ static int memory_block_offline(struct memory_block *mem)
 	 * Unaccount before offlining, such that unpopulated zone and kthreads
 	 * can properly be torn down in offline_pages().
 	 */
+	if (mem->altmap)
+		nr_vmemmap_pages = mem->altmap->free;
+
 	if (nr_vmemmap_pages)
 		adjust_present_page_count(pfn_to_page(start_pfn), mem->group,
 					  -nr_vmemmap_pages);
@@ -726,7 +733,7 @@ void memory_block_add_nid(struct memory_block *mem, int nid,
 #endif
 
 static int add_memory_block(unsigned long block_id, unsigned long state,
-			    unsigned long nr_vmemmap_pages,
+			    struct vmem_altmap *altmap,
 			    struct memory_group *group)
 {
 	struct memory_block *mem;
@@ -744,7 +751,7 @@ static int add_memory_block(unsigned long block_id, unsigned long state,
 	mem->start_section_nr = block_id * sections_per_block;
 	mem->state = state;
 	mem->nid = NUMA_NO_NODE;
-	mem->nr_vmemmap_pages = nr_vmemmap_pages;
+	mem->altmap = altmap;
 	INIT_LIST_HEAD(&mem->group_next);
 
 #ifndef CONFIG_NUMA
@@ -783,14 +790,14 @@ static int __init add_boot_memory_block(unsigned long base_section_nr)
 	if (section_count == 0)
 		return 0;
 	return add_memory_block(memory_block_id(base_section_nr),
-				MEM_ONLINE, 0,  NULL);
+				MEM_ONLINE, NULL,  NULL);
 }
 
 static int add_hotplug_memory_block(unsigned long block_id,
-				    unsigned long nr_vmemmap_pages,
+				    struct vmem_altmap *altmap,
 				    struct memory_group *group)
 {
-	return add_memory_block(block_id, MEM_OFFLINE, nr_vmemmap_pages, group);
+	return add_memory_block(block_id, MEM_OFFLINE, altmap, group);
 }
 
 static void remove_memory_block(struct memory_block *memory)
@@ -818,7 +825,7 @@ static void remove_memory_block(struct memory_block *memory)
  * Called under device_hotplug_lock.
  */
 int create_memory_block_devices(unsigned long start, unsigned long size,
-				unsigned long vmemmap_pages,
+				struct vmem_altmap *altmap,
 				struct memory_group *group)
 {
 	const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
@@ -832,7 +839,7 @@ int create_memory_block_devices(unsigned long start, unsigned long size,
 		return -EINVAL;
 
 	for (block_id = start_block_id; block_id != end_block_id; block_id++) {
-		ret = add_hotplug_memory_block(block_id, vmemmap_pages, group);
+		ret = add_hotplug_memory_block(block_id, altmap, group);
 		if (ret)
 			break;
 	}