memory unplug: memory hotplug cleanup
A clean up patch for "scanning memory resource [start, end)" operation.
Now, find_next_system_ram() function is used in memory hotplug, but this
interface is not easy to use and codes are complicated.
This patch adds walk_memory_resouce(start,len,arg,func) function.
The function 'func' is called per valid memory resouce range in [start,pfn).
[pbadari@us.ibm.com: Error handling in walk_memory_resource()]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 71ea9231..6187a85 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -110,9 +110,6 @@
int adjust_resource(struct resource *res, resource_size_t start,
resource_size_t size);
-/* get registered SYSTEM_RAM resources in specified area */
-extern int find_next_system_ram(struct resource *res);
-
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name))
#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name))
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index b573d1e..0a14dad 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -63,6 +63,14 @@
extern int __add_pages(struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
+/*
+ * Walk thorugh all memory which is registered as resource.
+ * arg is (start_pfn, nr_pages, private_arg_pointer)
+ */
+extern int walk_memory_resource(unsigned long start_pfn,
+ unsigned long nr_pages, void *arg,
+ int (*func)(unsigned long, unsigned long, void *));
+
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
#else
diff --git a/kernel/resource.c b/kernel/resource.c
index 9bd14fd..a358142 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -234,7 +234,7 @@
* the caller must specify res->start, res->end, res->flags.
* If found, returns 0, res is overwritten, if not found, returns -1.
*/
-int find_next_system_ram(struct resource *res)
+static int find_next_system_ram(struct resource *res)
{
resource_size_t start, end;
struct resource *p;
@@ -267,6 +267,30 @@
res->end = p->end;
return 0;
}
+int
+walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
+ int (*func)(unsigned long, unsigned long, void *))
+{
+ struct resource res;
+ unsigned long pfn, len;
+ u64 orig_end;
+ int ret = -1;
+ res.start = (u64) start_pfn << PAGE_SHIFT;
+ res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
+ res.flags = IORESOURCE_MEM;
+ orig_end = res.end;
+ while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
+ pfn = (unsigned long)(res.start >> PAGE_SHIFT);
+ len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
+ ret = (*func)(pfn, len, arg);
+ if (ret)
+ break;
+ res.start = res.end + 1;
+ res.end = orig_end;
+ }
+ return ret;
+}
+
#endif
/*
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9c12ae5..1cbe957 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -161,14 +161,27 @@
pgdat->node_start_pfn;
}
-int online_pages(unsigned long pfn, unsigned long nr_pages)
+static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
{
unsigned long i;
+ unsigned long onlined_pages = *(unsigned long *)arg;
+ struct page *page;
+ if (PageReserved(pfn_to_page(start_pfn)))
+ for (i = 0; i < nr_pages; i++) {
+ page = pfn_to_page(start_pfn + i);
+ online_page(page);
+ onlined_pages++;
+ }
+ *(unsigned long *)arg = onlined_pages;
+ return 0;
+}
+
+
+int online_pages(unsigned long pfn, unsigned long nr_pages)
+{
unsigned long flags;
unsigned long onlined_pages = 0;
- struct resource res;
- u64 section_end;
- unsigned long start_pfn;
struct zone *zone;
int need_zonelists_rebuild = 0;
@@ -191,28 +204,8 @@
if (!populated_zone(zone))
need_zonelists_rebuild = 1;
- res.start = (u64)pfn << PAGE_SHIFT;
- res.end = res.start + ((u64)nr_pages << PAGE_SHIFT) - 1;
- res.flags = IORESOURCE_MEM; /* we just need system ram */
- section_end = res.end;
-
- while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
- start_pfn = (unsigned long)(res.start >> PAGE_SHIFT);
- nr_pages = (unsigned long)
- ((res.end + 1 - res.start) >> PAGE_SHIFT);
-
- if (PageReserved(pfn_to_page(start_pfn))) {
- /* this region's page is not onlined now */
- for (i = 0; i < nr_pages; i++) {
- struct page *page = pfn_to_page(start_pfn + i);
- online_page(page);
- onlined_pages++;
- }
- }
-
- res.start = res.end + 1;
- res.end = section_end;
- }
+ walk_memory_resource(pfn, nr_pages, &onlined_pages,
+ online_pages_range);
zone->present_pages += onlined_pages;
zone->zone_pgdat->node_present_pages += onlined_pages;