Commit ea884641 authored by David Hildenbrand's avatar David Hildenbrand Committed by Linus Torvalds
Browse files

mm/memory_hotplug: move and simplify walk_memory_blocks() 

Let's move walk_memory_blocks() to the place where memory block logic
resides and simplify it.  While at it, add a type for the callback
function.

Link: http://lkml.kernel.org/r/20190614100114.311-6-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fbcf73ce

drivers/base/memory.c

+42 −0
Original line number Diff line number Diff line
@@ -44,6 +44,11 @@ static inline unsigned long pfn_to_block_id(unsigned long pfn) 
	return base_memory_block_id(pfn_to_section_nr(pfn));

}



static inline unsigned long phys_to_block_id(unsigned long phys)

{

	return pfn_to_block_id(PFN_DOWN(phys));

}



static int memory_subsys_online(struct device *dev);

static int memory_subsys_offline(struct device *dev);
@@ -851,3 +856,40 @@ out: 
		printk(KERN_ERR "%s() failed: %d\n", __func__, ret);

	return ret;

}



/**

 * walk_memory_blocks - walk through all present memory blocks overlapped

 *			by the range [start, start + size)

 *

 * @start: start address of the memory range

 * @size: size of the memory range

 * @arg: argument passed to func

 * @func: callback for each memory section walked

 *

 * This function walks through all present memory blocks overlapped by the

 * range [start, start + size), calling func on each memory block.

 *

 * In case func() returns an error, walking is aborted and the error is

 * returned.

 */

int walk_memory_blocks(unsigned long start, unsigned long size,

		       void *arg, walk_memory_blocks_func_t func)

{

	const unsigned long start_block_id = phys_to_block_id(start);

	const unsigned long end_block_id = phys_to_block_id(start + size - 1);

	struct memory_block *mem;

	unsigned long block_id;

	int ret = 0;



	for (block_id = start_block_id; block_id <= end_block_id; block_id++) {

		mem = find_memory_block_by_id(block_id, NULL);

		if (!mem)

			continue;



		ret = func(mem, arg);

		put_device(&mem->dev);

		if (ret)

			break;

	}

	return ret;

}

include/linux/memory.h

+3 −0
Original line number Diff line number Diff line
@@ -119,6 +119,9 @@ extern int memory_isolate_notify(unsigned long val, void *v); 
extern struct memory_block *find_memory_block_hinted(struct mem_section *,

							struct memory_block *);

extern struct memory_block *find_memory_block(struct mem_section *);

typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);

extern int walk_memory_blocks(unsigned long start, unsigned long size,

			      void *arg, walk_memory_blocks_func_t func);

#define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)

#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */

include/linux/memory_hotplug.h

+0 −2
Original line number Diff line number Diff line
@@ -340,8 +340,6 @@ static inline void __remove_memory(int nid, u64 start, u64 size) {} 
#endif /* CONFIG_MEMORY_HOTREMOVE */



extern void __ref free_area_init_core_hotplug(int nid);

extern int walk_memory_blocks(unsigned long start, unsigned long size,

		void *arg, int (*func)(struct memory_block *, void *));

extern int __add_memory(int nid, u64 start, u64 size);

extern int add_memory(int nid, u64 start, u64 size);

extern int add_memory_resource(int nid, struct resource *resource);

mm/memory_hotplug.c

+0 −55
Original line number Diff line number Diff line
@@ -1659,62 +1659,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 
{

	return __offline_pages(start_pfn, start_pfn + nr_pages);

}

#endif /* CONFIG_MEMORY_HOTREMOVE */



/**

 * walk_memory_blocks - walk through all present memory blocks overlapped

 *			by the range [start, start + size)

 *

 * @start: start address of the memory range

 * @size: size of the memory range

 * @arg: argument passed to func

 * @func: callback for each memory block walked

 *

 * This function walks through all present memory blocks overlapped by the

 * range [start, start + size), calling func on each memory block.

 *

 * Returns the return value of func.

 */

int walk_memory_blocks(unsigned long start, unsigned long size,

		void *arg, int (*func)(struct memory_block *, void *))

{

	const unsigned long start_pfn = PFN_DOWN(start);

	const unsigned long end_pfn = PFN_UP(start + size - 1);

	struct memory_block *mem = NULL;

	struct mem_section *section;

	unsigned long pfn, section_nr;

	int ret;



	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {

		section_nr = pfn_to_section_nr(pfn);

		if (!present_section_nr(section_nr))

			continue;



		section = __nr_to_section(section_nr);

		/* same memblock? */

		if (mem)

			if ((section_nr >= mem->start_section_nr) &&

			    (section_nr <= mem->end_section_nr))

				continue;



		mem = find_memory_block_hinted(section, mem);

		if (!mem)

			continue;



		ret = func(mem, arg);

		if (ret) {

			kobject_put(&mem->dev.kobj);

			return ret;

		}

	}



	if (mem)

		kobject_put(&mem->dev.kobj);



	return 0;

}



#ifdef CONFIG_MEMORY_HOTREMOVE

static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)

{

	int ret = !is_memblock_offlined(mem);

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