[PATCH v6 06/12] mm/hotplug: Add mem-hotplug restrictions for remove_memory()

From: Dan Williams
Date: Wed Apr 17 2019 - 14:53:17 EST


Teach the arch_remove_memory() path to consult the same 'struct
mhp_restrictions' context as was specified at arch_add_memory() time.

No functional change, this is a preparation step for teaching
__remove_pages() about how and when to allow sub-section hot-remove, and
a cleanup for an unnecessary "is_dev_zone()" special case.

Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/ia64/mm/init.c | 4 ++--
arch/powerpc/mm/mem.c | 5 +++--
arch/s390/mm/init.c | 2 +-
arch/sh/mm/init.c | 4 ++--
arch/x86/mm/init_32.c | 4 ++--
arch/x86/mm/init_64.c | 5 +++--
include/linux/memory_hotplug.h | 5 +++--
kernel/memremap.c | 14 ++++++++------
mm/memory_hotplug.c | 17 ++++++++---------
9 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index d28e29103bdb..86c69c87e7e8 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -683,14 +683,14 @@ int arch_add_memory(int nid, u64 start, u64 size,

#ifdef CONFIG_MEMORY_HOTREMOVE
void arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;

zone = page_zone(pfn_to_page(start_pfn));
- __remove_pages(zone, start_pfn, nr_pages, altmap);
+ __remove_pages(zone, start_pfn, nr_pages, restrictions);
}
#endif
#endif
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index cc9425fb9056..ccab989f397d 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -132,10 +132,11 @@ int __meminit arch_add_memory(int nid, u64 start, u64 size,

#ifdef CONFIG_MEMORY_HOTREMOVE
void __meminit arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ struct vmem_altmap *altmap = restrictions->altmap;
struct page *page;
int ret;

@@ -147,7 +148,7 @@ void __meminit arch_remove_memory(int nid, u64 start, u64 size,
if (altmap)
page += vmem_altmap_offset(altmap);

- __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
+ __remove_pages(page_zone(page), start_pfn, nr_pages, restrictions);

/* Remove htab bolted mappings for this section of memory */
start = (unsigned long)__va(start);
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 31b1071315d7..3af7b99af1b1 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -235,7 +235,7 @@ int arch_add_memory(int nid, u64 start, u64 size,

#ifdef CONFIG_MEMORY_HOTREMOVE
void arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
/*
* There is no hardware or firmware interface which could trigger a
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 5aeb4d7099a1..3cff7e4723e6 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -430,14 +430,14 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

#ifdef CONFIG_MEMORY_HOTREMOVE
void arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
unsigned long start_pfn = PFN_DOWN(start);
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;

zone = page_zone(pfn_to_page(start_pfn));
- __remove_pages(zone, start_pfn, nr_pages, altmap);
+ __remove_pages(zone, start_pfn, nr_pages, restrictions);
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 075e568098f2..ba888fd38f5d 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -861,14 +861,14 @@ int arch_add_memory(int nid, u64 start, u64 size,

#ifdef CONFIG_MEMORY_HOTREMOVE
void arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;

zone = page_zone(pfn_to_page(start_pfn));
- __remove_pages(zone, start_pfn, nr_pages, altmap);
+ __remove_pages(zone, start_pfn, nr_pages, restrictions);
}
#endif
#endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index bb018d09d2dc..4071632be007 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1142,8 +1142,9 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end)
}

void __ref arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap)
+ struct mhp_restrictions *restrictions)
{
+ struct vmem_altmap *altmap = restrictions->altmap;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct page *page = pfn_to_page(start_pfn);
@@ -1153,7 +1154,7 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
if (altmap)
page += vmem_altmap_offset(altmap);
zone = page_zone(page);
- __remove_pages(zone, start_pfn, nr_pages, altmap);
+ __remove_pages(zone, start_pfn, nr_pages, restrictions);
kernel_physical_mapping_remove(start, start + size);
}
#endif
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index ae892eef8b82..31b768bd1268 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -125,9 +125,10 @@ static inline bool movable_node_is_enabled(void)

#ifdef CONFIG_MEMORY_HOTREMOVE
extern void arch_remove_memory(int nid, u64 start, u64 size,
- struct vmem_altmap *altmap);
+ struct mhp_restrictions *restrictions);
extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
- unsigned long nr_pages, struct vmem_altmap *altmap);
+ unsigned long nr_pages,
+ struct mhp_restrictions *restrictions);
#endif /* CONFIG_MEMORY_HOTREMOVE */

/*
diff --git a/kernel/memremap.c b/kernel/memremap.c
index f355586ea54a..33475e211568 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -108,8 +108,11 @@ static void devm_memremap_pages_release(void *data)
__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
align_size >> PAGE_SHIFT, NULL);
} else {
- arch_remove_memory(nid, align_start, align_size,
- pgmap->altmap_valid ? &pgmap->altmap : NULL);
+ struct mhp_restrictions restrictions = {
+ .altmap = pgmap->altmap_valid ? &pgmap->altmap : NULL,
+ };
+
+ arch_remove_memory(nid, align_start, align_size, &restrictions);
kasan_remove_zero_shadow(__va(align_start), align_size);
}
mem_hotplug_done();
@@ -142,15 +145,14 @@ static void devm_memremap_pages_release(void *data)
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
resource_size_t align_start, align_size, align_end;
- struct vmem_altmap *altmap = pgmap->altmap_valid ?
- &pgmap->altmap : NULL;
struct resource *res = &pgmap->res;
struct dev_pagemap *conflict_pgmap;
struct mhp_restrictions restrictions = {
/*
* We do not want any optional features only our own memmap
*/
- .altmap = altmap,
+
+ .altmap = pgmap->altmap_valid ? &pgmap->altmap : NULL,
};
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
@@ -235,7 +237,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)

zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, altmap);
+ align_size >> PAGE_SHIFT, restrictions.altmap);
}

mem_hotplug_done();
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d5874f9d4043..055cea62be6e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -543,7 +543,7 @@ static void __remove_section(struct zone *zone, struct mem_section *ms,
* @zone: zone from which pages need to be removed
* @phys_start_pfn: starting pageframe (must be aligned to start of a section)
* @nr_pages: number of pages to remove (must be multiple of section size)
- * @altmap: alternative device page map or %NULL if default memmap is used
+ * @restrictions: optional alternative device page map and other features
*
* Generic helper function to remove section mappings and sysfs entries
* for the section of the memory we are removing. Caller needs to make
@@ -551,17 +551,15 @@ static void __remove_section(struct zone *zone, struct mem_section *ms,
* calling offline_pages().
*/
void __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages, struct vmem_altmap *altmap)
+ unsigned long nr_pages, struct mhp_restrictions *restrictions)
{
unsigned long i;
- unsigned long map_offset = 0;
int sections_to_remove;
+ unsigned long map_offset = 0;
+ struct vmem_altmap *altmap = restrictions->altmap;

- /* In the ZONE_DEVICE case device driver owns the memory region */
- if (is_dev_zone(zone)) {
- if (altmap)
- map_offset = vmem_altmap_offset(altmap);
- }
+ if (altmap)
+ map_offset = vmem_altmap_offset(altmap);

clear_zone_contiguous(zone);

@@ -1832,6 +1830,7 @@ static void __release_memory_resource(u64 start, u64 size)
*/
void __ref __remove_memory(int nid, u64 start, u64 size)
{
+ struct mhp_restrictions restrictions = { 0 };
int ret;

BUG_ON(check_hotplug_memory_range(start, size));
@@ -1853,7 +1852,7 @@ void __ref __remove_memory(int nid, u64 start, u64 size)
memblock_free(start, size);
memblock_remove(start, size);

- arch_remove_memory(nid, start, size, NULL);
+ arch_remove_memory(nid, start, size, &restrictions);
__release_memory_resource(start, size);

try_offline_node(nid);