Linux kernel mirror (for testing)
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linux
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/sparsemem.h>
20
21static unsigned long get_memblock_size(void)
22{
23 struct device_node *np;
24 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
25 struct resource r;
26
27 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
28 if (np) {
29 const __be64 *size;
30
31 size = of_get_property(np, "ibm,lmb-size", NULL);
32 if (size)
33 memblock_size = be64_to_cpup(size);
34 of_node_put(np);
35 } else if (machine_is(pseries)) {
36 /* This fallback really only applies to pseries */
37 unsigned int memzero_size = 0;
38
39 np = of_find_node_by_path("/memory@0");
40 if (np) {
41 if (!of_address_to_resource(np, 0, &r))
42 memzero_size = resource_size(&r);
43 of_node_put(np);
44 }
45
46 if (memzero_size) {
47 /* We now know the size of memory@0, use this to find
48 * the first memoryblock and get its size.
49 */
50 char buf[64];
51
52 sprintf(buf, "/memory@%x", memzero_size);
53 np = of_find_node_by_path(buf);
54 if (np) {
55 if (!of_address_to_resource(np, 0, &r))
56 memblock_size = resource_size(&r);
57 of_node_put(np);
58 }
59 }
60 }
61 return memblock_size;
62}
63
64/* WARNING: This is going to override the generic definition whenever
65 * pseries is built-in regardless of what platform is active at boot
66 * time. This is fine for now as this is the only "option" and it
67 * should work everywhere. If not, we'll have to turn this into a
68 * ppc_md. callback
69 */
70unsigned long memory_block_size_bytes(void)
71{
72 return get_memblock_size();
73}
74
75static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
76{
77 unsigned long start, start_pfn;
78 struct zone *zone;
79 int ret;
80 unsigned long section;
81 unsigned long sections_to_remove;
82
83 start_pfn = base >> PAGE_SHIFT;
84
85 if (!pfn_valid(start_pfn)) {
86 memblock_remove(base, memblock_size);
87 return 0;
88 }
89
90 zone = page_zone(pfn_to_page(start_pfn));
91
92 /*
93 * Remove section mappings and sysfs entries for the
94 * section of the memory we are removing.
95 *
96 * NOTE: Ideally, this should be done in generic code like
97 * remove_memory(). But remove_memory() gets called by writing
98 * to sysfs "state" file and we can't remove sysfs entries
99 * while writing to it. So we have to defer it to here.
100 */
101 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
102 for (section = 0; section < sections_to_remove; section++) {
103 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION;
104 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
105 if (ret)
106 return ret;
107 }
108
109 /*
110 * Update memory regions for memory remove
111 */
112 memblock_remove(base, memblock_size);
113
114 /*
115 * Remove htab bolted mappings for this section of memory
116 */
117 start = (unsigned long)__va(base);
118 ret = remove_section_mapping(start, start + memblock_size);
119
120 /* Ensure all vmalloc mappings are flushed in case they also
121 * hit that section of memory
122 */
123 vm_unmap_aliases();
124
125 return ret;
126}
127
128static int pseries_remove_memory(struct device_node *np)
129{
130 const char *type;
131 const unsigned int *regs;
132 unsigned long base;
133 unsigned int lmb_size;
134 int ret = -EINVAL;
135
136 /*
137 * Check to see if we are actually removing memory
138 */
139 type = of_get_property(np, "device_type", NULL);
140 if (type == NULL || strcmp(type, "memory") != 0)
141 return 0;
142
143 /*
144 * Find the bae address and size of the memblock
145 */
146 regs = of_get_property(np, "reg", NULL);
147 if (!regs)
148 return ret;
149
150 base = *(unsigned long *)regs;
151 lmb_size = regs[3];
152
153 ret = pseries_remove_memblock(base, lmb_size);
154 return ret;
155}
156
157static int pseries_add_memory(struct device_node *np)
158{
159 const char *type;
160 const unsigned int *regs;
161 unsigned long base;
162 unsigned int lmb_size;
163 int ret = -EINVAL;
164
165 /*
166 * Check to see if we are actually adding memory
167 */
168 type = of_get_property(np, "device_type", NULL);
169 if (type == NULL || strcmp(type, "memory") != 0)
170 return 0;
171
172 /*
173 * Find the base and size of the memblock
174 */
175 regs = of_get_property(np, "reg", NULL);
176 if (!regs)
177 return ret;
178
179 base = *(unsigned long *)regs;
180 lmb_size = regs[3];
181
182 /*
183 * Update memory region to represent the memory add
184 */
185 ret = memblock_add(base, lmb_size);
186 return (ret < 0) ? -EINVAL : 0;
187}
188
189static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
190{
191 struct of_drconf_cell *new_drmem, *old_drmem;
192 unsigned long memblock_size;
193 u32 entries;
194 u32 *p;
195 int i, rc = -EINVAL;
196
197 memblock_size = get_memblock_size();
198 if (!memblock_size)
199 return -EINVAL;
200
201 p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL);
202 if (!p)
203 return -EINVAL;
204
205 /* The first int of the property is the number of lmb's described
206 * by the property. This is followed by an array of of_drconf_cell
207 * entries. Get the niumber of entries and skip to the array of
208 * of_drconf_cell's.
209 */
210 entries = *p++;
211 old_drmem = (struct of_drconf_cell *)p;
212
213 p = (u32 *)pr->prop->value;
214 p++;
215 new_drmem = (struct of_drconf_cell *)p;
216
217 for (i = 0; i < entries; i++) {
218 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) &&
219 (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) {
220 rc = pseries_remove_memblock(old_drmem[i].base_addr,
221 memblock_size);
222 break;
223 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) &&
224 (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) {
225 rc = memblock_add(old_drmem[i].base_addr,
226 memblock_size);
227 rc = (rc < 0) ? -EINVAL : 0;
228 break;
229 }
230 }
231
232 return rc;
233}
234
235static int pseries_memory_notifier(struct notifier_block *nb,
236 unsigned long action, void *node)
237{
238 struct of_prop_reconfig *pr;
239 int err = 0;
240
241 switch (action) {
242 case OF_RECONFIG_ATTACH_NODE:
243 err = pseries_add_memory(node);
244 break;
245 case OF_RECONFIG_DETACH_NODE:
246 err = pseries_remove_memory(node);
247 break;
248 case OF_RECONFIG_UPDATE_PROPERTY:
249 pr = (struct of_prop_reconfig *)node;
250 if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
251 err = pseries_update_drconf_memory(pr);
252 break;
253 }
254 return notifier_from_errno(err);
255}
256
257static struct notifier_block pseries_mem_nb = {
258 .notifier_call = pseries_memory_notifier,
259};
260
261static int __init pseries_memory_hotplug_init(void)
262{
263 if (firmware_has_feature(FW_FEATURE_LPAR))
264 of_reconfig_notifier_register(&pseries_mem_nb);
265
266 return 0;
267}
268machine_device_initcall(pseries, pseries_memory_hotplug_init);