mm, memory_hotplug: add nid parameter to arch_remove_memory

Patch series "Do not touch pages in hot-remove path", v2.

This patchset aims for two things:

 1) A better definition about offline and hot-remove stage
 2) Solving bugs where we can access non-initialized pages
    during hot-remove operations [2] [3].

This is achieved by moving all page/zone handling to the offline
stage, so we do not need to access pages when hot-removing memory.

[1] https://patchwork.kernel.org/cover/10691415/
[2] https://patchwork.kernel.org/patch/10547445/
[3] https://www.spinics.net/lists/linux-mm/msg161316.html

This patch (of 5):

This is a preparation for the following-up patches.  The idea of passing
the nid is that it will allow us to get rid of the zone parameter
afterwards.

Link: http://lkml.kernel.org/r/20181127162005.15833-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.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>

arch/ia64/mm/init.c

@@ -661,7 +661,7 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;

arch/powerpc/mm/mem.c

@@ -139,7 +139,8 @@ int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int __meminit arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int __meminit arch_remove_memory(int nid, u64 start, u64 size,
+					struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;

arch/s390/mm/init.c

@@ -242,7 +242,7 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 {
 	/*
 	 * There is no hardware or firmware interface which could trigger a

arch/sh/mm/init.c

@@ -443,7 +443,7 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long nr_pages = size >> PAGE_SHIFT;

arch/x86/mm/init_32.c

@@ -860,7 +860,7 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;

arch/x86/mm/init_64.c

@@ -1141,7 +1141,8 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end)
 	remove_pagetable(start, end, true, NULL);
 }
 
-int __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+int __ref arch_remove_memory(int nid, u64 start, u64 size,
+				struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;

include/linux/memory_hotplug.h

@@ -107,8 +107,8 @@ static inline bool movable_node_is_enabled(void)
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-extern int arch_remove_memory(u64 start, u64 size,
-		struct vmem_altmap *altmap);
+extern int arch_remove_memory(int nid, u64 start, u64 size,
+				struct vmem_altmap *altmap);
 extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
 	unsigned long nr_pages, struct vmem_altmap *altmap);
 #endif /* CONFIG_MEMORY_HOTREMOVE */

kernel/memremap.c

@@ -87,6 +87,7 @@ static void devm_memremap_pages_release(void *data)
 	struct resource *res = &pgmap->res;
 	resource_size_t align_start, align_size;
 	unsigned long pfn;
+	int nid;
 
 	pgmap->kill(pgmap->ref);
 	for_each_device_pfn(pfn, pgmap)
@@ -97,13 +98,15 @@ static void devm_memremap_pages_release(void *data)
 	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
 		- align_start;
 
+	nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
+
 	mem_hotplug_begin();
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
 		pfn = align_start >> PAGE_SHIFT;
 		__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
 				align_size >> PAGE_SHIFT, NULL);
 	} else {
-		arch_remove_memory(align_start, align_size,
+		arch_remove_memory(nid, align_start, align_size,
 				pgmap->altmap_valid ? &pgmap->altmap : NULL);
 		kasan_remove_zero_shadow(__va(align_start), align_size);
 	}

mm/memory_hotplug.c

@@ -1841,7 +1841,7 @@ void __ref __remove_memory(int nid, u64 start, u64 size)
 	memblock_free(start, size);
 	memblock_remove(start, size);
 
-	arch_remove_memory(start, size, NULL);
+	arch_remove_memory(nid, start, size, NULL);
 
 	try_offline_node(nid);