1/*
2 * Copyright (C) 2004, 2013 Intel Corporation
3 * Author: Naveen B S <naveen.b.s@intel.com>
4 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
5 *
6 * All rights reserved.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or (at
11 * your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
16 * NON INFRINGEMENT. See the GNU General Public License for more
17 * details.
18 *
19 * ACPI based HotPlug driver that supports Memory Hotplug
20 * This driver fields notifications from firmware for memory add
21 * and remove operations and alerts the VM of the affected memory
22 * ranges.
23 */
24
25#include <linux/acpi.h>
26#include <linux/memory.h>
27#include <linux/memory_hotplug.h>
28
29#include "internal.h"
30
31#define ACPI_MEMORY_DEVICE_CLASS "memory"
32#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
33#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
34
35#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
36
37#undef PREFIX
38#define PREFIX "ACPI:memory_hp:"
39
40ACPI_MODULE_NAME("acpi_memhotplug");
41
42static const struct acpi_device_id memory_device_ids[] = {
43 {ACPI_MEMORY_DEVICE_HID, 0},
44 {"", 0},
45};
46
47#ifdef CONFIG_ACPI_HOTPLUG_MEMORY
48
49/* Memory Device States */
50#define MEMORY_INVALID_STATE 0
51#define MEMORY_POWER_ON_STATE 1
52#define MEMORY_POWER_OFF_STATE 2
53
54static int acpi_memory_device_add(struct acpi_device *device,
55 const struct acpi_device_id *not_used);
56static void acpi_memory_device_remove(struct acpi_device *device);
57
58static struct acpi_scan_handler memory_device_handler = {
59 .ids = memory_device_ids,
60 .attach = acpi_memory_device_add,
61 .detach = acpi_memory_device_remove,
62 .hotplug = {
63 .enabled = true,
64 },
65};
66
67struct acpi_memory_info {
68 struct list_head list;
69 u64 start_addr; /* Memory Range start physical addr */
70 u64 length; /* Memory Range length */
71 unsigned short caching; /* memory cache attribute */
72 unsigned short write_protect; /* memory read/write attribute */
73 unsigned int enabled:1;
74};
75
76struct acpi_memory_device {
77 struct acpi_device * device;
78 unsigned int state; /* State of the memory device */
79 struct list_head res_list;
80};
81
82static acpi_status
83acpi_memory_get_resource(struct acpi_resource *resource, void *context)
84{
85 struct acpi_memory_device *mem_device = context;
86 struct acpi_resource_address64 address64;
87 struct acpi_memory_info *info, *new;
88 acpi_status status;
89
90 status = acpi_resource_to_address64(resource, &address64);
91 if (ACPI_FAILURE(status) ||
92 (address64.resource_type != ACPI_MEMORY_RANGE))
93 return AE_OK;
94
95 list_for_each_entry(info, &mem_device->res_list, list) {
96 /* Can we combine the resource range information? */
97 if ((info->caching == address64.info.mem.caching) &&
98 (info->write_protect == address64.info.mem.write_protect) &&
99 (info->start_addr + info->length == address64.address.minimum)) {
100 info->length += address64.address.address_length;
101 return AE_OK;
102 }
103 }
104
105 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
106 if (!new)
107 return AE_ERROR;
108
109 INIT_LIST_HEAD(&new->list);
110 new->caching = address64.info.mem.caching;
111 new->write_protect = address64.info.mem.write_protect;
112 new->start_addr = address64.address.minimum;
113 new->length = address64.address.address_length;
114 list_add_tail(&new->list, &mem_device->res_list);
115
116 return AE_OK;
117}
118
119static void
120acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
121{
122 struct acpi_memory_info *info, *n;
123
124 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
125 kfree(info);
126 INIT_LIST_HEAD(&mem_device->res_list);
127}
128
129static int
130acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
131{
132 acpi_status status;
133
134 if (!list_empty(&mem_device->res_list))
135 return 0;
136
137 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
138 acpi_memory_get_resource, mem_device);
139 if (ACPI_FAILURE(status)) {
140 acpi_memory_free_device_resources(mem_device);
141 return -EINVAL;
142 }
143
144 return 0;
145}
146
147static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
148{
149 unsigned long long current_status;
150
151 /* Get device present/absent information from the _STA */
152 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
153 METHOD_NAME__STA, NULL,
154 &current_status)))
155 return -ENODEV;
156 /*
157 * Check for device status. Device should be
158 * present/enabled/functioning.
159 */
160 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
161 && (current_status & ACPI_STA_DEVICE_ENABLED)
162 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
163 return -ENODEV;
164
165 return 0;
166}
167
168static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
169{
170 return PFN_DOWN(info->start_addr);
171}
172
173static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
174{
175 return PFN_UP(info->start_addr + info->length-1);
176}
177
178static int acpi_bind_memblk(struct memory_block *mem, void *arg)
179{
180 return acpi_bind_one(&mem->dev, arg);
181}
182
183static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
184 struct acpi_device *adev)
185{
186 return walk_memory_range(acpi_meminfo_start_pfn(info),
187 acpi_meminfo_end_pfn(info), adev,
188 acpi_bind_memblk);
189}
190
191static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
192{
193 acpi_unbind_one(&mem->dev);
194 return 0;
195}
196
197static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
198{
199 walk_memory_range(acpi_meminfo_start_pfn(info),
200 acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
201}
202
203static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
204{
205 acpi_handle handle = mem_device->device->handle;
206 int result, num_enabled = 0;
207 struct acpi_memory_info *info;
208 int node;
209
210 node = acpi_get_node(handle);
211 /*
212 * Tell the VM there is more memory here...
213 * Note: Assume that this function returns zero on success
214 * We don't have memory-hot-add rollback function,now.
215 * (i.e. memory-hot-remove function)
216 */
217 list_for_each_entry(info, &mem_device->res_list, list) {
218 if (info->enabled) { /* just sanity check...*/
219 num_enabled++;
220 continue;
221 }
222 /*
223 * If the memory block size is zero, please ignore it.
224 * Don't try to do the following memory hotplug flowchart.
225 */
226 if (!info->length)
227 continue;
228 if (node < 0)
229 node = memory_add_physaddr_to_nid(info->start_addr);
230
231 result = __add_memory(node, info->start_addr, info->length);
232
233 /*
234 * If the memory block has been used by the kernel, add_memory()
235 * returns -EEXIST. If add_memory() returns the other error, it
236 * means that this memory block is not used by the kernel.
237 */
238 if (result && result != -EEXIST)
239 continue;
240
241 result = acpi_bind_memory_blocks(info, mem_device->device);
242 if (result) {
243 acpi_unbind_memory_blocks(info);
244 return -ENODEV;
245 }
246
247 info->enabled = 1;
248
249 /*
250 * Add num_enable even if add_memory() returns -EEXIST, so the
251 * device is bound to this driver.
252 */
253 num_enabled++;
254 }
255 if (!num_enabled) {
256 dev_err(&mem_device->device->dev, "add_memory failed\n");
257 mem_device->state = MEMORY_INVALID_STATE;
258 return -EINVAL;
259 }
260 /*
261 * Sometimes the memory device will contain several memory blocks.
262 * When one memory block is hot-added to the system memory, it will
263 * be regarded as a success.
264 * Otherwise if the last memory block can't be hot-added to the system
265 * memory, it will be failure and the memory device can't be bound with
266 * driver.
267 */
268 return 0;
269}
270
271static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
272{
273 acpi_handle handle = mem_device->device->handle;
274 struct acpi_memory_info *info, *n;
275 int nid = acpi_get_node(handle);
276
277 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
278 if (!info->enabled)
279 continue;
280
281 if (nid == NUMA_NO_NODE)
282 nid = memory_add_physaddr_to_nid(info->start_addr);
283
284 acpi_unbind_memory_blocks(info);
285 __remove_memory(nid, info->start_addr, info->length);
286 list_del(&info->list);
287 kfree(info);
288 }
289}
290
291static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
292{
293 if (!mem_device)
294 return;
295
296 acpi_memory_free_device_resources(mem_device);
297 mem_device->device->driver_data = NULL;
298 kfree(mem_device);
299}
300
301static int acpi_memory_device_add(struct acpi_device *device,
302 const struct acpi_device_id *not_used)
303{
304 struct acpi_memory_device *mem_device;
305 int result;
306
307 if (!device)
308 return -EINVAL;
309
310 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
311 if (!mem_device)
312 return -ENOMEM;
313
314 INIT_LIST_HEAD(&mem_device->res_list);
315 mem_device->device = device;
316 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
317 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
318 device->driver_data = mem_device;
319
320 /* Get the range from the _CRS */
321 result = acpi_memory_get_device_resources(mem_device);
322 if (result) {
323 device->driver_data = NULL;
324 kfree(mem_device);
325 return result;
326 }
327
328 /* Set the device state */
329 mem_device->state = MEMORY_POWER_ON_STATE;
330
331 result = acpi_memory_check_device(mem_device);
332 if (result) {
333 acpi_memory_device_free(mem_device);
334 return 0;
335 }
336
337 result = acpi_memory_enable_device(mem_device);
338 if (result) {
339 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
340 acpi_memory_device_free(mem_device);
341 return result;
342 }
343
344 dev_dbg(&device->dev, "Memory device configured by ACPI\n");
345 return 1;
346}
347
348static void acpi_memory_device_remove(struct acpi_device *device)
349{
350 struct acpi_memory_device *mem_device;
351
352 if (!device || !acpi_driver_data(device))
353 return;
354
355 mem_device = acpi_driver_data(device);
356 acpi_memory_remove_memory(mem_device);
357 acpi_memory_device_free(mem_device);
358}
359
360static bool __initdata acpi_no_memhotplug;
361
362void __init acpi_memory_hotplug_init(void)
363{
364 if (acpi_no_memhotplug) {
365 memory_device_handler.attach = NULL;
366 acpi_scan_add_handler(&memory_device_handler);
367 return;
368 }
369 acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
370}
371
372static int __init disable_acpi_memory_hotplug(char *str)
373{
374 acpi_no_memhotplug = true;
375 return 1;
376}
377__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
378
379#else
380
381static struct acpi_scan_handler memory_device_handler = {
382 .ids = memory_device_ids,
383};
384
385void __init acpi_memory_hotplug_init(void)
386{
387 acpi_scan_add_handler(&memory_device_handler);
388}
389
390#endif /* CONFIG_ACPI_HOTPLUG_MEMORY */
391