2 * pseries Memory Hotplug infrastructure.
4 * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
13 #include <linux/memblock.h>
14 #include <linux/vmalloc.h>
15 #include <linux/memory.h>
17 #include <asm/firmware.h>
18 #include <asm/machdep.h>
19 #include <asm/pSeries_reconfig.h>
20 #include <asm/sparsemem.h>
22 static unsigned long get_memblock_size(void)
24 struct device_node *np;
25 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
28 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
32 size = of_get_property(np, "ibm,lmb-size", NULL);
34 memblock_size = be64_to_cpup(size);
36 } else if (machine_is(pseries)) {
37 /* This fallback really only applies to pseries */
38 unsigned int memzero_size = 0;
40 np = of_find_node_by_path("/memory@0");
42 if (!of_address_to_resource(np, 0, &r))
43 memzero_size = resource_size(&r);
48 /* We now know the size of memory@0, use this to find
49 * the first memoryblock and get its size.
53 sprintf(buf, "/memory@%x", memzero_size);
54 np = of_find_node_by_path(buf);
56 if (!of_address_to_resource(np, 0, &r))
57 memblock_size = resource_size(&r);
65 /* WARNING: This is going to override the generic definition whenever
66 * pseries is built-in regardless of what platform is active at boot
67 * time. This is fine for now as this is the only "option" and it
68 * should work everywhere. If not, we'll have to turn this into a
71 unsigned long memory_block_size_bytes(void)
73 return get_memblock_size();
76 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
78 unsigned long start, start_pfn;
81 unsigned long section;
82 unsigned long sections_to_remove;
84 start_pfn = base >> PAGE_SHIFT;
86 if (!pfn_valid(start_pfn)) {
87 memblock_remove(base, memblock_size);
91 zone = page_zone(pfn_to_page(start_pfn));
94 * Remove section mappings and sysfs entries for the
95 * section of the memory we are removing.
97 * NOTE: Ideally, this should be done in generic code like
98 * remove_memory(). But remove_memory() gets called by writing
99 * to sysfs "state" file and we can't remove sysfs entries
100 * while writing to it. So we have to defer it to here.
102 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
103 for (section = 0; section < sections_to_remove; section++) {
104 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION;
105 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
111 * Update memory regions for memory remove
113 memblock_remove(base, memblock_size);
116 * Remove htab bolted mappings for this section of memory
118 start = (unsigned long)__va(base);
119 ret = remove_section_mapping(start, start + memblock_size);
121 /* Ensure all vmalloc mappings are flushed in case they also
122 * hit that section of memory
129 static int pseries_remove_memory(struct device_node *np)
132 const unsigned int *regs;
134 unsigned int lmb_size;
138 * Check to see if we are actually removing memory
140 type = of_get_property(np, "device_type", NULL);
141 if (type == NULL || strcmp(type, "memory") != 0)
145 * Find the bae address and size of the memblock
147 regs = of_get_property(np, "reg", NULL);
151 base = *(unsigned long *)regs;
154 ret = pseries_remove_memblock(base, lmb_size);
158 static int pseries_add_memory(struct device_node *np)
161 const unsigned int *regs;
163 unsigned int lmb_size;
167 * Check to see if we are actually adding memory
169 type = of_get_property(np, "device_type", NULL);
170 if (type == NULL || strcmp(type, "memory") != 0)
174 * Find the base and size of the memblock
176 regs = of_get_property(np, "reg", NULL);
180 base = *(unsigned long *)regs;
184 * Update memory region to represent the memory add
186 ret = memblock_add(base, lmb_size);
187 return (ret < 0) ? -EINVAL : 0;
190 static int pseries_drconf_memory(unsigned long *base, unsigned int action)
192 unsigned long memblock_size;
195 memblock_size = get_memblock_size();
199 if (action == PSERIES_DRCONF_MEM_ADD) {
200 rc = memblock_add(*base, memblock_size);
201 rc = (rc < 0) ? -EINVAL : 0;
202 } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
203 rc = pseries_remove_memblock(*base, memblock_size);
211 static int pseries_memory_notifier(struct notifier_block *nb,
212 unsigned long action, void *node)
217 case PSERIES_RECONFIG_ADD:
218 err = pseries_add_memory(node);
220 case PSERIES_RECONFIG_REMOVE:
221 err = pseries_remove_memory(node);
223 case PSERIES_DRCONF_MEM_ADD:
224 case PSERIES_DRCONF_MEM_REMOVE:
225 err = pseries_drconf_memory(node, action);
228 return notifier_from_errno(err);
231 static struct notifier_block pseries_mem_nb = {
232 .notifier_call = pseries_memory_notifier,
235 static int __init pseries_memory_hotplug_init(void)
237 if (firmware_has_feature(FW_FEATURE_LPAR))
238 pSeries_reconfig_notifier_register(&pseries_mem_nb);
242 machine_device_initcall(pseries, pseries_memory_hotplug_init);