2 * Copyright (C) 2012 Intel Corporation
3 * Author: Liu Jinsong <jinsong.liu@intel.com>
4 * Author: Jiang Yunhong <yunhong.jiang@intel.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/types.h>
24 #include <linux/acpi.h>
26 #include <xen/interface/platform.h>
27 #include <asm/xen/hypercall.h>
29 #define PREFIX "ACPI:xen_memory_hotplug:"
31 struct acpi_memory_info {
32 struct list_head list;
33 u64 start_addr; /* Memory Range start physical addr */
34 u64 length; /* Memory Range length */
35 unsigned short caching; /* memory cache attribute */
36 unsigned short write_protect; /* memory read/write attribute */
37 /* copied from buffer getting from _CRS */
38 unsigned int enabled:1;
41 struct acpi_memory_device {
42 struct acpi_device *device;
43 struct list_head res_list;
46 static bool acpi_hotmem_initialized __read_mostly;
48 static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
51 struct xen_platform_op op;
53 op.cmd = XENPF_mem_hotadd;
54 op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
55 op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
56 op.u.mem_add.pxm = pxm;
58 rc = HYPERVISOR_dom0_op(&op);
60 pr_err(PREFIX "Xen Hotplug Memory Add failed on "
61 "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
62 (unsigned long)info->start_addr,
63 (unsigned long)(info->start_addr + info->length),
69 static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
73 struct acpi_memory_info *info;
78 pxm = xen_acpi_get_pxm(mem_device->device->handle);
82 list_for_each_entry(info, &mem_device->res_list, list) {
83 if (info->enabled) { /* just sanity check...*/
91 result = xen_hotadd_memory(pxm, info);
105 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
107 struct acpi_memory_device *mem_device = context;
108 struct acpi_resource_address64 address64;
109 struct acpi_memory_info *info, *new;
112 status = acpi_resource_to_address64(resource, &address64);
113 if (ACPI_FAILURE(status) ||
114 (address64.resource_type != ACPI_MEMORY_RANGE))
117 list_for_each_entry(info, &mem_device->res_list, list) {
118 if ((info->caching == address64.info.mem.caching) &&
119 (info->write_protect == address64.info.mem.write_protect) &&
120 (info->start_addr + info->length == address64.minimum)) {
121 info->length += address64.address_length;
126 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
130 INIT_LIST_HEAD(&new->list);
131 new->caching = address64.info.mem.caching;
132 new->write_protect = address64.info.mem.write_protect;
133 new->start_addr = address64.minimum;
134 new->length = address64.address_length;
135 list_add_tail(&new->list, &mem_device->res_list);
141 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
144 struct acpi_memory_info *info, *n;
146 if (!list_empty(&mem_device->res_list))
149 status = acpi_walk_resources(mem_device->device->handle,
150 METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
152 if (ACPI_FAILURE(status)) {
153 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
155 INIT_LIST_HEAD(&mem_device->res_list);
162 static int acpi_memory_get_device(acpi_handle handle,
163 struct acpi_memory_device **mem_device)
165 struct acpi_device *device = NULL;
168 acpi_scan_lock_acquire();
170 acpi_bus_get_device(handle, &device);
175 * Now add the notified device. This creates the acpi_device
176 * and invokes .add function
178 result = acpi_bus_scan(handle);
180 pr_warn(PREFIX "ACPI namespace scan failed\n");
184 result = acpi_bus_get_device(handle, &device);
186 pr_warn(PREFIX "Missing device object\n");
192 *mem_device = acpi_driver_data(device);
193 if (!(*mem_device)) {
194 pr_err(PREFIX "driver data not found\n");
200 acpi_scan_lock_release();
204 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
206 unsigned long long current_status;
208 /* Get device present/absent information from the _STA */
209 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
210 "_STA", NULL, ¤t_status)))
213 * Check for device status. Device should be
214 * present/enabled/functioning.
216 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
217 && (current_status & ACPI_STA_DEVICE_ENABLED)
218 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
224 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
226 pr_debug(PREFIX "Xen does not support memory hotremove\n");
231 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
233 struct acpi_memory_device *mem_device;
234 struct acpi_device *device;
235 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
238 case ACPI_NOTIFY_BUS_CHECK:
239 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
240 "\nReceived BUS CHECK notification for device\n"));
242 case ACPI_NOTIFY_DEVICE_CHECK:
243 if (event == ACPI_NOTIFY_DEVICE_CHECK)
244 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
245 "\nReceived DEVICE CHECK notification for device\n"));
247 if (acpi_memory_get_device(handle, &mem_device)) {
248 pr_err(PREFIX "Cannot find driver data\n");
252 ost_code = ACPI_OST_SC_SUCCESS;
255 case ACPI_NOTIFY_EJECT_REQUEST:
256 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
257 "\nReceived EJECT REQUEST notification for device\n"));
259 acpi_scan_lock_acquire();
260 if (acpi_bus_get_device(handle, &device)) {
261 acpi_scan_lock_release();
262 pr_err(PREFIX "Device doesn't exist\n");
265 mem_device = acpi_driver_data(device);
267 acpi_scan_lock_release();
268 pr_err(PREFIX "Driver Data is NULL\n");
273 * TBD: implement acpi_memory_disable_device and invoke
274 * acpi_bus_remove if Xen support hotremove in the future
276 acpi_memory_disable_device(mem_device);
277 acpi_scan_lock_release();
281 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
282 "Unsupported event [0x%x]\n", event));
283 /* non-hotplug event; possibly handled by other handler */
287 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
291 static int xen_acpi_memory_device_add(struct acpi_device *device)
294 struct acpi_memory_device *mem_device = NULL;
300 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
304 INIT_LIST_HEAD(&mem_device->res_list);
305 mem_device->device = device;
306 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
307 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
308 device->driver_data = mem_device;
310 /* Get the range from the _CRS */
311 result = acpi_memory_get_device_resources(mem_device);
318 * For booting existed memory devices, early boot code has recognized
319 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
320 * hotplug is not necessary for them.
321 * For hot-added memory devices during runtime, it need hypercall to
322 * Xen hypervisor to add memory.
324 if (!acpi_hotmem_initialized)
327 if (!acpi_memory_check_device(mem_device))
328 result = xen_acpi_memory_enable_device(mem_device);
333 static int xen_acpi_memory_device_remove(struct acpi_device *device)
335 struct acpi_memory_device *mem_device = NULL;
337 if (!device || !acpi_driver_data(device))
340 mem_device = acpi_driver_data(device);
347 * Helper function to check for memory device
349 static acpi_status is_memory_device(acpi_handle handle)
353 struct acpi_device_info *info;
355 status = acpi_get_object_info(handle, &info);
356 if (ACPI_FAILURE(status))
359 if (!(info->valid & ACPI_VALID_HID)) {
364 hardware_id = info->hardware_id.string;
365 if ((hardware_id == NULL) ||
366 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
374 acpi_memory_register_notify_handler(acpi_handle handle,
375 u32 level, void *ctxt, void **retv)
379 status = is_memory_device(handle);
380 if (ACPI_FAILURE(status))
381 return AE_OK; /* continue */
383 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
384 acpi_memory_device_notify, NULL);
390 acpi_memory_deregister_notify_handler(acpi_handle handle,
391 u32 level, void *ctxt, void **retv)
395 status = is_memory_device(handle);
396 if (ACPI_FAILURE(status))
397 return AE_OK; /* continue */
399 status = acpi_remove_notify_handler(handle,
401 acpi_memory_device_notify);
403 return AE_OK; /* continue */
406 static const struct acpi_device_id memory_device_ids[] = {
407 {ACPI_MEMORY_DEVICE_HID, 0},
410 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
412 static struct acpi_driver xen_acpi_memory_device_driver = {
413 .name = "acpi_memhotplug",
414 .class = ACPI_MEMORY_DEVICE_CLASS,
415 .ids = memory_device_ids,
417 .add = xen_acpi_memory_device_add,
418 .remove = xen_acpi_memory_device_remove,
422 static int __init xen_acpi_memory_device_init(void)
427 if (!xen_initial_domain())
430 /* unregister the stub which only used to reserve driver space */
431 xen_stub_memory_device_exit();
433 result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
435 xen_stub_memory_device_init();
439 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
441 acpi_memory_register_notify_handler,
444 if (ACPI_FAILURE(status)) {
445 pr_warn(PREFIX "walk_namespace failed\n");
446 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
447 xen_stub_memory_device_init();
451 acpi_hotmem_initialized = true;
455 static void __exit xen_acpi_memory_device_exit(void)
459 if (!xen_initial_domain())
462 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
464 acpi_memory_deregister_notify_handler,
466 if (ACPI_FAILURE(status))
467 pr_warn(PREFIX "walk_namespace failed\n");
469 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
472 * stub reserve space again to prevent any chance of native
475 xen_stub_memory_device_init();
479 module_init(xen_acpi_memory_device_init);
480 module_exit(xen_acpi_memory_device_exit);
481 ACPI_MODULE_NAME("xen-acpi-memhotplug");
482 MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
483 MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
484 MODULE_LICENSE("GPL");