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1/*
2 * pseries Memory Hotplug infrastructure.
3 *
4 * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
5 *
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.
10 */
11
12#include <linux/of.h>
13#include <linux/memblock.h>
14#include <linux/vmalloc.h>
15#include <linux/memory.h>
16
17#include <asm/firmware.h>
18#include <asm/machdep.h>
19#include <asm/pSeries_reconfig.h>
20#include <asm/sparsemem.h>
21
22static unsigned long get_memblock_size(void)
23{
24 struct device_node *np;
25 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
26 struct resource r;
27
28 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
29 if (np) {
30 const __be64 *size;
31
32 size = of_get_property(np, "ibm,lmb-size", NULL);
33 if (size)
34 memblock_size = be64_to_cpup(size);
35 of_node_put(np);
36 } else if (machine_is(pseries)) {
37 /* This fallback really only applies to pseries */
38 unsigned int memzero_size = 0;
39
40 np = of_find_node_by_path("/memory@0");
41 if (np) {
42 if (!of_address_to_resource(np, 0, &r))
43 memzero_size = resource_size(&r);
44 of_node_put(np);
45 }
46
47 if (memzero_size) {
48 /* We now know the size of memory@0, use this to find
49 * the first memoryblock and get its size.
50 */
51 char buf[64];
52
53 sprintf(buf, "/memory@%x", memzero_size);
54 np = of_find_node_by_path(buf);
55 if (np) {
56 if (!of_address_to_resource(np, 0, &r))
57 memblock_size = resource_size(&r);
58 of_node_put(np);
59 }
60 }
61 }
62 return memblock_size;
63}
64
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
69 * ppc_md. callback
70 */
71unsigned long memory_block_size_bytes(void)
72{
73 return get_memblock_size();
74}
75
76static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
77{
78 unsigned long start, start_pfn;
79 struct zone *zone;
80 int ret;
81
82 start_pfn = base >> PAGE_SHIFT;
83
84 if (!pfn_valid(start_pfn)) {
85 memblock_remove(base, memblock_size);
86 return 0;
87 }
88
89 zone = page_zone(pfn_to_page(start_pfn));
90
91 /*
92 * Remove section mappings and sysfs entries for the
93 * section of the memory we are removing.
94 *
95 * NOTE: Ideally, this should be done in generic code like
96 * remove_memory(). But remove_memory() gets called by writing
97 * to sysfs "state" file and we can't remove sysfs entries
98 * while writing to it. So we have to defer it to here.
99 */
100 ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT);
101 if (ret)
102 return ret;
103
104 /*
105 * Update memory regions for memory remove
106 */
107 memblock_remove(base, memblock_size);
108
109 /*
110 * Remove htab bolted mappings for this section of memory
111 */
112 start = (unsigned long)__va(base);
113 ret = remove_section_mapping(start, start + memblock_size);
114
115 /* Ensure all vmalloc mappings are flushed in case they also
116 * hit that section of memory
117 */
118 vm_unmap_aliases();
119
120 return ret;
121}
122
123static int pseries_remove_memory(struct device_node *np)
124{
125 const char *type;
126 const unsigned int *regs;
127 unsigned long base;
128 unsigned int lmb_size;
129 int ret = -EINVAL;
130
131 /*
132 * Check to see if we are actually removing memory
133 */
134 type = of_get_property(np, "device_type", NULL);
135 if (type == NULL || strcmp(type, "memory") != 0)
136 return 0;
137
138 /*
139 * Find the bae address and size of the memblock
140 */
141 regs = of_get_property(np, "reg", NULL);
142 if (!regs)
143 return ret;
144
145 base = *(unsigned long *)regs;
146 lmb_size = regs[3];
147
148 ret = pseries_remove_memblock(base, lmb_size);
149 return ret;
150}
151
152static int pseries_add_memory(struct device_node *np)
153{
154 const char *type;
155 const unsigned int *regs;
156 unsigned long base;
157 unsigned int lmb_size;
158 int ret = -EINVAL;
159
160 /*
161 * Check to see if we are actually adding memory
162 */
163 type = of_get_property(np, "device_type", NULL);
164 if (type == NULL || strcmp(type, "memory") != 0)
165 return 0;
166
167 /*
168 * Find the base and size of the memblock
169 */
170 regs = of_get_property(np, "reg", NULL);
171 if (!regs)
172 return ret;
173
174 base = *(unsigned long *)regs;
175 lmb_size = regs[3];
176
177 /*
178 * Update memory region to represent the memory add
179 */
180 ret = memblock_add(base, lmb_size);
181 return (ret < 0) ? -EINVAL : 0;
182}
183
184static int pseries_drconf_memory(unsigned long *base, unsigned int action)
185{
186 unsigned long memblock_size;
187 int rc;
188
189 memblock_size = get_memblock_size();
190 if (!memblock_size)
191 return -EINVAL;
192
193 if (action == PSERIES_DRCONF_MEM_ADD) {
194 rc = memblock_add(*base, memblock_size);
195 rc = (rc < 0) ? -EINVAL : 0;
196 } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
197 rc = pseries_remove_memblock(*base, memblock_size);
198 } else {
199 rc = -EINVAL;
200 }
201
202 return rc;
203}
204
205static int pseries_memory_notifier(struct notifier_block *nb,
206 unsigned long action, void *node)
207{
208 int err = 0;
209
210 switch (action) {
211 case PSERIES_RECONFIG_ADD:
212 err = pseries_add_memory(node);
213 break;
214 case PSERIES_RECONFIG_REMOVE:
215 err = pseries_remove_memory(node);
216 break;
217 case PSERIES_DRCONF_MEM_ADD:
218 case PSERIES_DRCONF_MEM_REMOVE:
219 err = pseries_drconf_memory(node, action);
220 break;
221 }
222 return notifier_from_errno(err);
223}
224
225static struct notifier_block pseries_mem_nb = {
226 .notifier_call = pseries_memory_notifier,
227};
228
229static int __init pseries_memory_hotplug_init(void)
230{
231 if (firmware_has_feature(FW_FEATURE_LPAR))
232 pSeries_reconfig_notifier_register(&pseries_mem_nb);
233
234 return 0;
235}
236machine_device_initcall(pseries, pseries_memory_hotplug_init);