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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 static const struct acpi_device_id memory_device_ids[] = {
 48         {ACPI_MEMORY_DEVICE_HID, 0},
 49         {"", 0},
 50 };
 51 
 52 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
 53 
 54 /* Memory Device States */
 55 #define MEMORY_INVALID_STATE    0
 56 #define MEMORY_POWER_ON_STATE   1
 57 #define MEMORY_POWER_OFF_STATE  2
 58 
 59 static int acpi_memory_device_add(struct acpi_device *device,
 60                                   const struct acpi_device_id *not_used);
 61 static void acpi_memory_device_remove(struct acpi_device *device);
 62 
 63 static struct acpi_scan_handler memory_device_handler = {
 64         .ids = memory_device_ids,
 65         .attach = acpi_memory_device_add,
 66         .detach = acpi_memory_device_remove,
 67         .hotplug = {
 68                 .enabled = true,
 69         },
 70 };
 71 
 72 struct acpi_memory_info {
 73         struct list_head list;
 74         u64 start_addr;         /* Memory Range start physical addr */
 75         u64 length;             /* Memory Range length */
 76         unsigned short caching; /* memory cache attribute */
 77         unsigned short write_protect;   /* memory read/write attribute */
 78         unsigned int enabled:1;
 79 };
 80 
 81 struct acpi_memory_device {
 82         struct acpi_device * device;
 83         unsigned int state;     /* State of the memory device */
 84         struct list_head res_list;
 85 };
 86 
 87 static acpi_status
 88 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
 89 {
 90         struct acpi_memory_device *mem_device = context;
 91         struct acpi_resource_address64 address64;
 92         struct acpi_memory_info *info, *new;
 93         acpi_status status;
 94 
 95         status = acpi_resource_to_address64(resource, &address64);
 96         if (ACPI_FAILURE(status) ||
 97             (address64.resource_type != ACPI_MEMORY_RANGE))
 98                 return AE_OK;
 99 
100         list_for_each_entry(info, &mem_device->res_list, list) {
101                 /* Can we combine the resource range information? */
102                 if ((info->caching == address64.info.mem.caching) &&
103                     (info->write_protect == address64.info.mem.write_protect) &&
104                     (info->start_addr + info->length == address64.minimum)) {
105                         info->length += address64.address_length;
106                         return AE_OK;
107                 }
108         }
109 
110         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
111         if (!new)
112                 return AE_ERROR;
113 
114         INIT_LIST_HEAD(&new->list);
115         new->caching = address64.info.mem.caching;
116         new->write_protect = address64.info.mem.write_protect;
117         new->start_addr = address64.minimum;
118         new->length = address64.address_length;
119         list_add_tail(&new->list, &mem_device->res_list);
120 
121         return AE_OK;
122 }
123 
124 static void
125 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
126 {
127         struct acpi_memory_info *info, *n;
128 
129         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
130                 kfree(info);
131         INIT_LIST_HEAD(&mem_device->res_list);
132 }
133 
134 static int
135 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
136 {
137         acpi_status status;
138 
139         if (!list_empty(&mem_device->res_list))
140                 return 0;
141 
142         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
143                                      acpi_memory_get_resource, mem_device);
144         if (ACPI_FAILURE(status)) {
145                 acpi_memory_free_device_resources(mem_device);
146                 return -EINVAL;
147         }
148 
149         return 0;
150 }
151 
152 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
153 {
154         unsigned long long current_status;
155 
156         /* Get device present/absent information from the _STA */
157         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
158                                                METHOD_NAME__STA, NULL,
159                                                &current_status)))
160                 return -ENODEV;
161         /*
162          * Check for device status. Device should be
163          * present/enabled/functioning.
164          */
165         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
166               && (current_status & ACPI_STA_DEVICE_ENABLED)
167               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
168                 return -ENODEV;
169 
170         return 0;
171 }
172 
173 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
174 {
175         return PFN_DOWN(info->start_addr);
176 }
177 
178 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
179 {
180         return PFN_UP(info->start_addr + info->length-1);
181 }
182 
183 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
184 {
185         return acpi_bind_one(&mem->dev, arg);
186 }
187 
188 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
189                                    struct acpi_device *adev)
190 {
191         return walk_memory_range(acpi_meminfo_start_pfn(info),
192                                  acpi_meminfo_end_pfn(info), adev,
193                                  acpi_bind_memblk);
194 }
195 
196 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
197 {
198         acpi_unbind_one(&mem->dev);
199         return 0;
200 }
201 
202 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
203 {
204         walk_memory_range(acpi_meminfo_start_pfn(info),
205                           acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
206 }
207 
208 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
209 {
210         acpi_handle handle = mem_device->device->handle;
211         int result, num_enabled = 0;
212         struct acpi_memory_info *info;
213         int node;
214 
215         node = acpi_get_node(handle);
216         /*
217          * Tell the VM there is more memory here...
218          * Note: Assume that this function returns zero on success
219          * We don't have memory-hot-add rollback function,now.
220          * (i.e. memory-hot-remove function)
221          */
222         list_for_each_entry(info, &mem_device->res_list, list) {
223                 if (info->enabled) { /* just sanity check...*/
224                         num_enabled++;
225                         continue;
226                 }
227                 /*
228                  * If the memory block size is zero, please ignore it.
229                  * Don't try to do the following memory hotplug flowchart.
230                  */
231                 if (!info->length)
232                         continue;
233                 if (node < 0)
234                         node = memory_add_physaddr_to_nid(info->start_addr);
235 
236                 result = add_memory(node, info->start_addr, info->length);
237 
238                 /*
239                  * If the memory block has been used by the kernel, add_memory()
240                  * returns -EEXIST. If add_memory() returns the other error, it
241                  * means that this memory block is not used by the kernel.
242                  */
243                 if (result && result != -EEXIST)
244                         continue;
245 
246                 result = acpi_bind_memory_blocks(info, mem_device->device);
247                 if (result) {
248                         acpi_unbind_memory_blocks(info);
249                         return -ENODEV;
250                 }
251 
252                 info->enabled = 1;
253 
254                 /*
255                  * Add num_enable even if add_memory() returns -EEXIST, so the
256                  * device is bound to this driver.
257                  */
258                 num_enabled++;
259         }
260         if (!num_enabled) {
261                 dev_err(&mem_device->device->dev, "add_memory failed\n");
262                 mem_device->state = MEMORY_INVALID_STATE;
263                 return -EINVAL;
264         }
265         /*
266          * Sometimes the memory device will contain several memory blocks.
267          * When one memory block is hot-added to the system memory, it will
268          * be regarded as a success.
269          * Otherwise if the last memory block can't be hot-added to the system
270          * memory, it will be failure and the memory device can't be bound with
271          * driver.
272          */
273         return 0;
274 }
275 
276 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
277 {
278         acpi_handle handle = mem_device->device->handle;
279         struct acpi_memory_info *info, *n;
280         int nid = acpi_get_node(handle);
281 
282         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
283                 if (!info->enabled)
284                         continue;
285 
286                 if (nid == NUMA_NO_NODE)
287                         nid = memory_add_physaddr_to_nid(info->start_addr);
288 
289                 acpi_unbind_memory_blocks(info);
290                 remove_memory(nid, info->start_addr, info->length);
291                 list_del(&info->list);
292                 kfree(info);
293         }
294 }
295 
296 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
297 {
298         if (!mem_device)
299                 return;
300 
301         acpi_memory_free_device_resources(mem_device);
302         mem_device->device->driver_data = NULL;
303         kfree(mem_device);
304 }
305 
306 static int acpi_memory_device_add(struct acpi_device *device,
307                                   const struct acpi_device_id *not_used)
308 {
309         struct acpi_memory_device *mem_device;
310         int result;
311 
312         if (!device)
313                 return -EINVAL;
314 
315         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
316         if (!mem_device)
317                 return -ENOMEM;
318 
319         INIT_LIST_HEAD(&mem_device->res_list);
320         mem_device->device = device;
321         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
322         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
323         device->driver_data = mem_device;
324 
325         /* Get the range from the _CRS */
326         result = acpi_memory_get_device_resources(mem_device);
327         if (result) {
328                 device->driver_data = NULL;
329                 kfree(mem_device);
330                 return result;
331         }
332 
333         /* Set the device state */
334         mem_device->state = MEMORY_POWER_ON_STATE;
335 
336         result = acpi_memory_check_device(mem_device);
337         if (result) {
338                 acpi_memory_device_free(mem_device);
339                 return 0;
340         }
341 
342         result = acpi_memory_enable_device(mem_device);
343         if (result) {
344                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
345                 acpi_memory_device_free(mem_device);
346                 return result;
347         }
348 
349         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
350         return 1;
351 }
352 
353 static void acpi_memory_device_remove(struct acpi_device *device)
354 {
355         struct acpi_memory_device *mem_device;
356 
357         if (!device || !acpi_driver_data(device))
358                 return;
359 
360         mem_device = acpi_driver_data(device);
361         acpi_memory_remove_memory(mem_device);
362         acpi_memory_device_free(mem_device);
363 }
364 
365 static bool __initdata acpi_no_memhotplug;
366 
367 void __init acpi_memory_hotplug_init(void)
368 {
369         if (acpi_no_memhotplug) {
370                 memory_device_handler.attach = NULL;
371                 acpi_scan_add_handler(&memory_device_handler);
372                 return;
373         }
374         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
375 }
376 
377 static int __init disable_acpi_memory_hotplug(char *str)
378 {
379         acpi_no_memhotplug = true;
380         return 1;
381 }
382 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
383 
384 #else
385 
386 static struct acpi_scan_handler memory_device_handler = {
387         .ids = memory_device_ids,
388 };
389 
390 void __init acpi_memory_hotplug_init(void)
391 {
392         acpi_scan_add_handler(&memory_device_handler);
393 }
394 
395 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */
396 

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