3  * Memory subsystem support
9  * a SPARSEMEM-memory-model system's physical memory in /sysfs.
19 #include <linux/memory.h>
29 #define MEMORY_CLASS_NAME	"memory"
79  * Memory blocks are cached in a local radix tree to avoid
86  * Memory groups, indexed by memory group id (mgid).
119  * Show the first physical section index (number) of this memory block.
191 	 * they describe (they remain until the memory is unplugged), doing  in memory_block_online()
192 	 * their initialization and accounting at memory onlining/offlining  in memory_block_online()
194 	 * belong to the same zone as the memory they backed.  in memory_block_online()
367  * covered by a memory block, allowing for identifying which memory blocks
368  * comprise a storage increment. Since a memory block spans complete
446  * Show the memory block size (shared by all memory blocks).
457  * Memory auto online policy.
526  * Support for offlining pages of memory
572  * A reference for the returned memory block device is acquired.
617  * register_memory - Setup a sysfs device for a memory block
620 int register_memory(struct memory_block *memory)  in register_memory()  argument
624 	memory->dev.bus = &memory_subsys;  in register_memory()
625 	memory->dev.id = memory->start_section_nr / sections_per_block;  in register_memory()
626 	memory->dev.release = memory_block_release;  in register_memory()
627 	memory->dev.groups = memory_memblk_attr_groups;  in register_memory()
628 	memory->dev.offline = memory->state == MEM_OFFLINE;  in register_memory()
630 	ret = device_register(&memory->dev);  in register_memory()
632 		put_device(&memory->dev);  in register_memory()
635 	ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory,  in register_memory()
638 		put_device(&memory->dev);  in register_memory()
639 		device_unregister(&memory->dev);  in register_memory()
692 static void unregister_memory(struct memory_block *memory)  in unregister_memory()  argument
694 	if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys))  in unregister_memory()
697 	WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL);  in unregister_memory()
699 	if (memory->group) {  in unregister_memory()
700 		list_del(&memory->group_next);  in unregister_memory()
701 		memory->group = NULL;  in unregister_memory()
705 	put_device(&memory->dev);  in unregister_memory()
706 	device_unregister(&memory->dev);  in unregister_memory()
710  * Create memory block devices for the given memory area. Start and size
711  * have to be aligned to memory block granularity. Memory block devices
750  * Remove memory block devices for the given memory area. Start and size
751  * have to be aligned to memory block granularity. Memory block devices
776 /* return true if the memory block is offlined, otherwise, return false */
807  * Initialize the sysfs support for memory devices. At the time this function
808  * is called, we cannot have concurrent creation/deletion of memory block
816 	/* Validate the configured memory block size */  in memory_dev_init()
819 		panic("Memory block size not suitable: 0x%lx\n", block_sz);  in memory_dev_init()
827 	 * Create entries for memory sections that were found  in memory_dev_init()
834 			panic("%s() failed to add memory block: %d\n", __func__,  in memory_dev_init()
840  * walk_memory_blocks - walk through all present memory blocks overlapped
843  * @start: start address of the memory range
844  * @size: size of the memory range
846  * @func: callback for each memory section walked
848  * This function walks through all present memory blocks overlapped by the
849  * range [start, start + size), calling func on each memory block.
895  * for_each_memory_block - walk through all present memory blocks
898  * @func: callback for each memory block walked
900  * This function walks through all present memory blocks, calling func on
901  * each memory block.
919  * memory groups. Note that the passed memory group will be copied to a
920  * dynamically allocated memory group. After this call, the passed
921  * memory group should no longer be used.
950  * memory_group_register_static() - Register a static memory group.
952  * @max_pages: The maximum number of pages we'll have in this static memory
955  * Register a new static memory group and return the memory group id.
956  * All memory in the group belongs to a single unit, such as a DIMM. All
957  * memory belonging to a static memory group is added in one go to be removed
960  * Returns an error if out of memory, if the node id is invalid, if no new
961  * memory groups can be registered, or if max_pages is invalid (0). Otherwise,
962  * returns the new memory group id.
980  * memory_group_register_dynamic() - Register a dynamic memory group.
982  * @unit_pages: Unit in pages in which is memory added/removed in this dynamic
983  *		memory group.
985  * Register a new dynamic memory group and return the memory group id.
986  * Memory within a dynamic memory group is added/removed dynamically
989  * Returns an error if out of memory, if the node id is invalid, if no new
990  * memory groups can be registered, or if unit_pages is invalid (0, not a
991  * power of two, smaller than a single memory block). Otherwise, returns the
992  * new memory group id.
1012  * memory_group_unregister() - Unregister a memory group.
1013  * @mgid: the memory group id
1015  * Unregister a memory group. If any memory block still belongs to this
1016  * memory group, unregistering will fail.
1018  * Returns -EINVAL if the memory group id is invalid, returns -EBUSY if some
1019  * memory blocks still belong to this memory group and returns 0 if
1041  * This is an internal helper only to be used in core memory hotplug code to
1042  * lookup a memory group. We don't care about locking, as we don't expect a
1043  * memory group to get unregistered while adding memory to it -- because
1044  * the group and the memory is managed by the same driver.
1052  * This is an internal helper only to be used in core memory hotplug code to
1053  * walk all dynamic memory groups excluding a given memory group, either