Prepare the memory hot-{add,remove} paths for handling sub-section
ranges by plumbing the starting page frame and number of pages being
handled through arch_{add,remove}_memory() to
sparse_{add,remove}_one_section().
This is simply plumbing, small cleanups, and some identifier renames. No
intended functional changes.
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/x86/mm/init_64.c | 11 +++++
include/linux/memory_hotplug.h | 7 ++-
mm/memory_hotplug.c | 85 ++++++++++++++++++++++------------------
mm/sparse.c | 7 ++-
4 files changed, 66 insertions(+), 44 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 799887eada60..4ae817a79ac3 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -781,6 +781,17 @@ int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
{
int ret;
+ /*
+ * Only allow partial section hotplug for !memblock ranges,
+ * since register_new_memory() requires section alignment, and
+ * CONFIG_SPARSEMEM_VMEMMAP=n requires sections to be fully
+ * populated.
+ */
+ if ((!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) || want_memblock)
+ && ((start_pfn & ~PAGE_SECTION_MASK)
+ || (nr_pages & ~PAGE_SECTION_MASK)))
+ return -EINVAL;
+
ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
WARN_ON_ONCE(ret);
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 8ade08c50d26..83ee937fb67f 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -336,9 +336,10 @@ extern int arch_add_memory(int nid, u64 start, u64 size,
extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages, struct vmem_altmap *altmap);
extern bool is_memblock_offlined(struct memory_block *mem);
-extern int sparse_add_one_section(int nid, unsigned long start_pfn,
- struct vmem_altmap *altmap);
-extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
+extern int sparse_add_section(int nid, unsigned long pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap);
+extern void sparse_remove_section(struct zone *zone, struct mem_section *ms,
+ unsigned long pfn, unsigned long nr_pages,
unsigned long map_offset, struct vmem_altmap *altmap);
extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
unsigned long pnum);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0ea3bb58d223..e093348f5d04 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -250,22 +250,23 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
}
#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
-static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
- struct vmem_altmap *altmap, bool want_memblock)
+static int __meminit __add_section(int nid, unsigned long pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap,
+ bool want_memblock)
{
int ret;
- if (pfn_valid(phys_start_pfn))
+ if (pfn_valid(pfn))
return -EEXIST;
- ret = sparse_add_one_section(nid, phys_start_pfn, altmap);
+ ret = sparse_add_section(nid, pfn, nr_pages, altmap);
if (ret < 0)
return ret;
if (!want_memblock)
return 0;
- return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn));
+ return hotplug_memory_register(nid, __pfn_to_section(pfn));
}
/*
@@ -274,23 +275,18 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
* call this function after deciding the zone to which to
* 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)
+int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages,
+ struct vmem_altmap *altmap, bool want_memblock)
{
unsigned long i;
int err = 0;
int start_sec, end_sec;
- /* during initialize mem_map, align hot-added range to section */
- start_sec = pfn_to_section_nr(phys_start_pfn);
- end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
-
if (altmap) {
/*
* Validate altmap is within bounds of the total request
*/
- if (altmap->base_pfn != phys_start_pfn
+ if (altmap->base_pfn != pfn
|| vmem_altmap_offset(altmap) > nr_pages) {
pr_warn_once("memory add fail, invalid altmap\n");
err = -EINVAL;
@@ -299,9 +295,16 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
altmap->alloc = 0;
}
+ start_sec = pfn_to_section_nr(pfn);
+ end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(nid, section_nr_to_pfn(i), altmap,
- want_memblock);
+ unsigned long pfns;
+
+ pfns = min(nr_pages, PAGES_PER_SECTION
+ - (pfn & ~PAGE_SECTION_MASK));
+ err = __add_section(nid, pfn, pfns, altmap, want_memblock);
+ pfn += pfns;
+ nr_pages -= pfns;
/*
* EEXIST is finally dealt with by ioresource collision
@@ -506,10 +509,10 @@ static void shrink_pgdat_span(struct pglist_data *pgdat,
pgdat->node_spanned_pages = 0;
}
-static void __remove_zone(struct zone *zone, unsigned long start_pfn)
+static void __remove_zone(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages)
{
struct pglist_data *pgdat = zone->zone_pgdat;
- int nr_pages = PAGES_PER_SECTION;
unsigned long flags;
pgdat_resize_lock(zone->zone_pgdat, &flags);
@@ -518,11 +521,11 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn)
pgdat_resize_unlock(zone->zone_pgdat, &flags);
}
-static int __remove_section(struct zone *zone, struct mem_section *ms,
- unsigned long map_offset, struct vmem_altmap *altmap)
+static int __remove_section(struct zone *zone, unsigned long pfn,
+ unsigned long nr_pages, unsigned long map_offset,
+ struct vmem_altmap *altmap)
{
- unsigned long start_pfn;
- int scn_nr;
+ struct mem_section *ms = __nr_to_section(pfn_to_section_nr(pfn));
int ret = -EINVAL;
if (!valid_section(ms))
@@ -532,18 +535,16 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,
if (ret)
return ret;
- scn_nr = __section_nr(ms);
- start_pfn = section_nr_to_pfn((unsigned long)scn_nr);
- __remove_zone(zone, start_pfn);
+ __remove_zone(zone, pfn, nr_pages);
- sparse_remove_one_section(zone, ms, map_offset, altmap);
+ sparse_remove_section(zone, ms, pfn, nr_pages, map_offset, altmap);
return 0;
}
/**
* __remove_pages() - remove sections of pages from a zone
* @zone: zone from which pages need to be removed
- * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
+ * @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
*
@@ -552,12 +553,11 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,
* sure that pages are marked reserved and zones are adjust properly by
* calling offline_pages().
*/
-int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+int __remove_pages(struct zone *zone, unsigned long pfn,
unsigned long nr_pages, struct vmem_altmap *altmap)
{
- unsigned long i;
unsigned long map_offset = 0;
- int sections_to_remove, ret = 0;
+ int i, start_sec, end_sec, ret = 0;
/* In the ZONE_DEVICE case device driver owns the memory region */
if (is_dev_zone(zone)) {
@@ -566,7 +566,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
} else {
resource_size_t start, size;
- start = phys_start_pfn << PAGE_SHIFT;
+ start = pfn << PAGE_SHIFT;
size = nr_pages * PAGE_SIZE;
ret = release_mem_region_adjustable(&iomem_resource, start,
@@ -582,18 +582,27 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
clear_zone_contiguous(zone);
/*
- * We can only remove entire sections
+ * Only ZONE_DEVICE memory is enabled to remove
+ * section-unaligned ranges. See register_new_memory() which
+ * assumes section alignment and is skipped for ZONE_DEVICE
+ * ranges.
*/
- BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
- BUG_ON(nr_pages % PAGES_PER_SECTION);
+ if (!is_dev_zone(zone) && ((pfn | nr_pages) & ~PAGE_SECTION_MASK)) {
+ WARN(1, "section unaligned removal not supported\n");
+ return -EINVAL;
+ }
- sections_to_remove = nr_pages / PAGES_PER_SECTION;
- for (i = 0; i < sections_to_remove; i++) {
- unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+ start_sec = pfn_to_section_nr(pfn);
+ end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
+ for (i = start_sec; i <= end_sec; i++) {
+ unsigned long pfns;
cond_resched();
- ret = __remove_section(zone, __pfn_to_section(pfn), map_offset,
- altmap);
+ pfns = min(nr_pages, PAGES_PER_SECTION
+ - (pfn & ~PAGE_SECTION_MASK));
+ ret = __remove_section(zone, pfn, pfns, map_offset, altmap);
+ pfn += pfns;
+ nr_pages -= pfns;
map_offset = 0;
if (ret)
break;
diff --git a/mm/sparse.c b/mm/sparse.c
index 38f80639c6cc..767713c88cf5 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -748,8 +748,8 @@ static void free_map_bootmem(struct page *memmap)
* set. If this is <=0, then that means that the passed-in
* map was not consumed and must be freed.
*/
-int __meminit sparse_add_one_section(int nid, unsigned long start_pfn,
- struct vmem_altmap *altmap)
+int __meminit sparse_add_section(int nid, unsigned long start_pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap)
{
unsigned long section_nr = pfn_to_section_nr(start_pfn);
struct mem_section_usage *usage;
@@ -858,7 +858,8 @@ static void free_section_usage(struct page *memmap,
free_map_bootmem(memmap);
}
-void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
+void sparse_remove_section(struct zone *zone, struct mem_section *ms,
+ unsigned long pfn, unsigned long nr_pages,
unsigned long map_offset, struct vmem_altmap *altmap)
{
struct page *memmap = NULL;
