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/of_address.h>
14 #include <linux/memblock.h>
15 #include <linux/vmalloc.h>
16 #include <linux/memory.h>
18 #include <asm/firmware.h>
19 #include <asm/machdep.h>
21 #include <asm/sparsemem.h>
23 static unsigned long get_memblock_size(void)
25 struct device_node *np;
26 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
29 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
33 size = of_get_property(np, "ibm,lmb-size", NULL);
35 memblock_size = be64_to_cpup(size);
37 } else if (machine_is(pseries)) {
38 /* This fallback really only applies to pseries */
39 unsigned int memzero_size = 0;
41 np = of_find_node_by_path("/memory@0");
43 if (!of_address_to_resource(np, 0, &r))
44 memzero_size = resource_size(&r);
49 /* We now know the size of memory@0, use this to find
50 * the first memoryblock and get its size.
54 sprintf(buf, "/memory@%x", memzero_size);
55 np = of_find_node_by_path(buf);
57 if (!of_address_to_resource(np, 0, &r))
58 memblock_size = resource_size(&r);
66 /* WARNING: This is going to override the generic definition whenever
67 * pseries is built-in regardless of what platform is active at boot
68 * time. This is fine for now as this is the only "option" and it
69 * should work everywhere. If not, we'll have to turn this into a
72 unsigned long memory_block_size_bytes(void)
74 return get_memblock_size();
77 #ifdef CONFIG_MEMORY_HOTREMOVE
78 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
80 unsigned long start, start_pfn;
83 unsigned long section;
84 unsigned long sections_to_remove;
86 start_pfn = base >> PAGE_SHIFT;
88 if (!pfn_valid(start_pfn)) {
89 memblock_remove(base, memblock_size);
93 zone = page_zone(pfn_to_page(start_pfn));
96 * Remove section mappings and sysfs entries for the
97 * section of the memory we are removing.
99 * NOTE: Ideally, this should be done in generic code like
100 * remove_memory(). But remove_memory() gets called by writing
101 * to sysfs "state" file and we can't remove sysfs entries
102 * while writing to it. So we have to defer it to here.
104 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
105 for (section = 0; section < sections_to_remove; section++) {
106 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION;
107 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
113 * Update memory regions for memory remove
115 memblock_remove(base, memblock_size);
118 * Remove htab bolted mappings for this section of memory
120 start = (unsigned long)__va(base);
121 ret = remove_section_mapping(start, start + memblock_size);
123 /* Ensure all vmalloc mappings are flushed in case they also
124 * hit that section of memory
131 static int pseries_remove_memory(struct device_node *np)
134 const unsigned int *regs;
136 unsigned int lmb_size;
140 * Check to see if we are actually removing memory
142 type = of_get_property(np, "device_type", NULL);
143 if (type == NULL || strcmp(type, "memory") != 0)
147 * Find the bae address and size of the memblock
149 regs = of_get_property(np, "reg", NULL);
153 base = *(unsigned long *)regs;
156 ret = pseries_remove_memblock(base, lmb_size);
160 static inline int pseries_remove_memblock(unsigned long base,
161 unsigned int memblock_size)
165 static inline int pseries_remove_memory(struct device_node *np)
169 #endif /* CONFIG_MEMORY_HOTREMOVE */
171 static int pseries_add_memory(struct device_node *np)
174 const unsigned int *regs;
176 unsigned int lmb_size;
180 * Check to see if we are actually adding memory
182 type = of_get_property(np, "device_type", NULL);
183 if (type == NULL || strcmp(type, "memory") != 0)
187 * Find the base and size of the memblock
189 regs = of_get_property(np, "reg", NULL);
193 base = *(unsigned long *)regs;
197 * Update memory region to represent the memory add
199 ret = memblock_add(base, lmb_size);
200 return (ret < 0) ? -EINVAL : 0;
203 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
205 struct of_drconf_cell *new_drmem, *old_drmem;
206 unsigned long memblock_size;
211 memblock_size = get_memblock_size();
215 p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL);
219 /* The first int of the property is the number of lmb's described
220 * by the property. This is followed by an array of of_drconf_cell
221 * entries. Get the niumber of entries and skip to the array of
225 old_drmem = (struct of_drconf_cell *)p;
227 p = (u32 *)pr->prop->value;
229 new_drmem = (struct of_drconf_cell *)p;
231 for (i = 0; i < entries; i++) {
232 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) &&
233 (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) {
234 rc = pseries_remove_memblock(old_drmem[i].base_addr,
237 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) &&
238 (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) {
239 rc = memblock_add(old_drmem[i].base_addr,
241 rc = (rc < 0) ? -EINVAL : 0;
249 static int pseries_memory_notifier(struct notifier_block *nb,
250 unsigned long action, void *node)
252 struct of_prop_reconfig *pr;
256 case OF_RECONFIG_ATTACH_NODE:
257 err = pseries_add_memory(node);
259 case OF_RECONFIG_DETACH_NODE:
260 err = pseries_remove_memory(node);
262 case OF_RECONFIG_UPDATE_PROPERTY:
263 pr = (struct of_prop_reconfig *)node;
264 if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
265 err = pseries_update_drconf_memory(pr);
268 return notifier_from_errno(err);
271 static struct notifier_block pseries_mem_nb = {
272 .notifier_call = pseries_memory_notifier,
275 static int __init pseries_memory_hotplug_init(void)
277 if (firmware_has_feature(FW_FEATURE_LPAR))
278 of_reconfig_notifier_register(&pseries_mem_nb);
282 machine_device_initcall(pseries, pseries_memory_hotplug_init);