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Linux/drivers/acpi/acpi_memhotplug.c

  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  * You should have received a copy of the GNU General Public License
 20  * along with this program; if not, write to the Free Software
 21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 22  *
 23  *
 24  * ACPI based HotPlug driver that supports Memory Hotplug
 25  * This driver fields notifications from firmware for memory add
 26  * and remove operations and alerts the VM of the affected memory
 27  * ranges.
 28  */
 29 
 30 #include <linux/acpi.h>
 31 #include <linux/memory.h>
 32 #include <linux/memory_hotplug.h>
 33 
 34 #include "internal.h"
 35 
 36 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
 37 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
 38 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
 39 
 40 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
 41 
 42 #undef PREFIX
 43 #define         PREFIX          "ACPI:memory_hp:"
 44 
 45 ACPI_MODULE_NAME("acpi_memhotplug");
 46 
 47 /* Memory Device States */
 48 #define MEMORY_INVALID_STATE    0
 49 #define MEMORY_POWER_ON_STATE   1
 50 #define MEMORY_POWER_OFF_STATE  2
 51 
 52 static int acpi_memory_device_add(struct acpi_device *device,
 53                                   const struct acpi_device_id *not_used);
 54 static void acpi_memory_device_remove(struct acpi_device *device);
 55 
 56 static const struct acpi_device_id memory_device_ids[] = {
 57         {ACPI_MEMORY_DEVICE_HID, 0},
 58         {"", 0},
 59 };
 60 
 61 static struct acpi_scan_handler memory_device_handler = {
 62         .ids = memory_device_ids,
 63         .attach = acpi_memory_device_add,
 64         .detach = acpi_memory_device_remove,
 65         .hotplug = {
 66                 .enabled = true,
 67         },
 68 };
 69 
 70 struct acpi_memory_info {
 71         struct list_head list;
 72         u64 start_addr;         /* Memory Range start physical addr */
 73         u64 length;             /* Memory Range length */
 74         unsigned short caching; /* memory cache attribute */
 75         unsigned short write_protect;   /* memory read/write attribute */
 76         unsigned int enabled:1;
 77 };
 78 
 79 struct acpi_memory_device {
 80         struct acpi_device * device;
 81         unsigned int state;     /* State of the memory device */
 82         struct list_head res_list;
 83 };
 84 
 85 static acpi_status
 86 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
 87 {
 88         struct acpi_memory_device *mem_device = context;
 89         struct acpi_resource_address64 address64;
 90         struct acpi_memory_info *info, *new;
 91         acpi_status status;
 92 
 93         status = acpi_resource_to_address64(resource, &address64);
 94         if (ACPI_FAILURE(status) ||
 95             (address64.resource_type != ACPI_MEMORY_RANGE))
 96                 return AE_OK;
 97 
 98         list_for_each_entry(info, &mem_device->res_list, list) {
 99                 /* Can we combine the resource range information? */
100                 if ((info->caching == address64.info.mem.caching) &&
101                     (info->write_protect == address64.info.mem.write_protect) &&
102                     (info->start_addr + info->length == address64.minimum)) {
103                         info->length += address64.address_length;
104                         return AE_OK;
105                 }
106         }
107 
108         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
109         if (!new)
110                 return AE_ERROR;
111 
112         INIT_LIST_HEAD(&new->list);
113         new->caching = address64.info.mem.caching;
114         new->write_protect = address64.info.mem.write_protect;
115         new->start_addr = address64.minimum;
116         new->length = address64.address_length;
117         list_add_tail(&new->list, &mem_device->res_list);
118 
119         return AE_OK;
120 }
121 
122 static void
123 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
124 {
125         struct acpi_memory_info *info, *n;
126 
127         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
128                 kfree(info);
129         INIT_LIST_HEAD(&mem_device->res_list);
130 }
131 
132 static int
133 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
134 {
135         acpi_status status;
136 
137         if (!list_empty(&mem_device->res_list))
138                 return 0;
139 
140         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
141                                      acpi_memory_get_resource, mem_device);
142         if (ACPI_FAILURE(status)) {
143                 acpi_memory_free_device_resources(mem_device);
144                 return -EINVAL;
145         }
146 
147         return 0;
148 }
149 
150 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
151 {
152         unsigned long long current_status;
153 
154         /* Get device present/absent information from the _STA */
155         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
156                                                METHOD_NAME__STA, NULL,
157                                                &current_status)))
158                 return -ENODEV;
159         /*
160          * Check for device status. Device should be
161          * present/enabled/functioning.
162          */
163         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
164               && (current_status & ACPI_STA_DEVICE_ENABLED)
165               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
166                 return -ENODEV;
167 
168         return 0;
169 }
170 
171 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
172 {
173         return PFN_DOWN(info->start_addr);
174 }
175 
176 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
177 {
178         return PFN_UP(info->start_addr + info->length-1);
179 }
180 
181 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
182 {
183         return acpi_bind_one(&mem->dev, arg);
184 }
185 
186 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
187                                    struct acpi_device *adev)
188 {
189         return walk_memory_range(acpi_meminfo_start_pfn(info),
190                                  acpi_meminfo_end_pfn(info), adev,
191                                  acpi_bind_memblk);
192 }
193 
194 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
195 {
196         acpi_unbind_one(&mem->dev);
197         return 0;
198 }
199 
200 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
201 {
202         walk_memory_range(acpi_meminfo_start_pfn(info),
203                           acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
204 }
205 
206 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
207 {
208         acpi_handle handle = mem_device->device->handle;
209         int result, num_enabled = 0;
210         struct acpi_memory_info *info;
211         int node;
212 
213         node = acpi_get_node(handle);
214         /*
215          * Tell the VM there is more memory here...
216          * Note: Assume that this function returns zero on success
217          * We don't have memory-hot-add rollback function,now.
218          * (i.e. memory-hot-remove function)
219          */
220         list_for_each_entry(info, &mem_device->res_list, list) {
221                 if (info->enabled) { /* just sanity check...*/
222                         num_enabled++;
223                         continue;
224                 }
225                 /*
226                  * If the memory block size is zero, please ignore it.
227                  * Don't try to do the following memory hotplug flowchart.
228                  */
229                 if (!info->length)
230                         continue;
231                 if (node < 0)
232                         node = memory_add_physaddr_to_nid(info->start_addr);
233 
234                 result = add_memory(node, info->start_addr, info->length);
235 
236                 /*
237                  * If the memory block has been used by the kernel, add_memory()
238                  * returns -EEXIST. If add_memory() returns the other error, it
239                  * means that this memory block is not used by the kernel.
240                  */
241                 if (result && result != -EEXIST)
242                         continue;
243 
244                 result = acpi_bind_memory_blocks(info, mem_device->device);
245                 if (result) {
246                         acpi_unbind_memory_blocks(info);
247                         return -ENODEV;
248                 }
249 
250                 info->enabled = 1;
251 
252                 /*
253                  * Add num_enable even if add_memory() returns -EEXIST, so the
254                  * device is bound to this driver.
255                  */
256                 num_enabled++;
257         }
258         if (!num_enabled) {
259                 dev_err(&mem_device->device->dev, "add_memory failed\n");
260                 mem_device->state = MEMORY_INVALID_STATE;
261                 return -EINVAL;
262         }
263         /*
264          * Sometimes the memory device will contain several memory blocks.
265          * When one memory block is hot-added to the system memory, it will
266          * be regarded as a success.
267          * Otherwise if the last memory block can't be hot-added to the system
268          * memory, it will be failure and the memory device can't be bound with
269          * driver.
270          */
271         return 0;
272 }
273 
274 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
275 {
276         acpi_handle handle = mem_device->device->handle;
277         struct acpi_memory_info *info, *n;
278         int nid = acpi_get_node(handle);
279 
280         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
281                 if (!info->enabled)
282                         continue;
283 
284                 if (nid == NUMA_NO_NODE)
285                         nid = memory_add_physaddr_to_nid(info->start_addr);
286 
287                 acpi_unbind_memory_blocks(info);
288                 remove_memory(nid, info->start_addr, info->length);
289                 list_del(&info->list);
290                 kfree(info);
291         }
292 }
293 
294 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
295 {
296         if (!mem_device)
297                 return;
298 
299         acpi_memory_free_device_resources(mem_device);
300         mem_device->device->driver_data = NULL;
301         kfree(mem_device);
302 }
303 
304 static int acpi_memory_device_add(struct acpi_device *device,
305                                   const struct acpi_device_id *not_used)
306 {
307         struct acpi_memory_device *mem_device;
308         int result;
309 
310         if (!device)
311                 return -EINVAL;
312 
313         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
314         if (!mem_device)
315                 return -ENOMEM;
316 
317         INIT_LIST_HEAD(&mem_device->res_list);
318         mem_device->device = device;
319         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
320         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
321         device->driver_data = mem_device;
322 
323         /* Get the range from the _CRS */
324         result = acpi_memory_get_device_resources(mem_device);
325         if (result) {
326                 device->driver_data = NULL;
327                 kfree(mem_device);
328                 return result;
329         }
330 
331         /* Set the device state */
332         mem_device->state = MEMORY_POWER_ON_STATE;
333 
334         result = acpi_memory_check_device(mem_device);
335         if (result) {
336                 acpi_memory_device_free(mem_device);
337                 return 0;
338         }
339 
340         result = acpi_memory_enable_device(mem_device);
341         if (result) {
342                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
343                 acpi_memory_device_free(mem_device);
344                 return result;
345         }
346 
347         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
348         return 1;
349 }
350 
351 static void acpi_memory_device_remove(struct acpi_device *device)
352 {
353         struct acpi_memory_device *mem_device;
354 
355         if (!device || !acpi_driver_data(device))
356                 return;
357 
358         mem_device = acpi_driver_data(device);
359         acpi_memory_remove_memory(mem_device);
360         acpi_memory_device_free(mem_device);
361 }
362 
363 static bool __initdata acpi_no_memhotplug;
364 
365 void __init acpi_memory_hotplug_init(void)
366 {
367         if (acpi_no_memhotplug)
368                 return;
369 
370         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
371 }
372 
373 static int __init disable_acpi_memory_hotplug(char *str)
374 {
375         acpi_no_memhotplug = true;
376         return 1;
377 }
378 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
379 

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