[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / xen / xen-acpi-memhotplug.c

/*
 * Copyright (C) 2012 Intel Corporation
 *    Author: Liu Jinsong <jinsong.liu@intel.com>
 *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <acpi/acpi_drivers.h>
#include <xen/acpi.h>
#include <xen/interface/platform.h>
#include <asm/xen/hypercall.h>

#define PREFIX "ACPI:xen_memory_hotplug:"

struct acpi_memory_info {
	struct list_head list;
	u64 start_addr;		/* Memory Range start physical addr */
	u64 length;		/* Memory Range length */
	unsigned short caching;	/* memory cache attribute */
	unsigned short write_protect;	/* memory read/write attribute */
				/* copied from buffer getting from _CRS */
	unsigned int enabled:1;
};

struct acpi_memory_device {
	struct acpi_device *device;
	struct list_head res_list;
};

static bool acpi_hotmem_initialized __read_mostly;

static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
{
	int rc;
	struct xen_platform_op op;

	op.cmd = XENPF_mem_hotadd;
	op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
	op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
	op.u.mem_add.pxm = pxm;

	rc = HYPERVISOR_dom0_op(&op);
	if (rc)
		pr_err(PREFIX "Xen Hotplug Memory Add failed on "
			"0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
			(unsigned long)info->start_addr,
			(unsigned long)(info->start_addr + info->length),
			pxm, rc);

	return rc;
}

static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
{
	int pxm, result;
	int num_enabled = 0;
	struct acpi_memory_info *info;

	if (!mem_device)
		return -EINVAL;

	pxm = xen_acpi_get_pxm(mem_device->device->handle);
	if (pxm < 0)
		return pxm;

	list_for_each_entry(info, &mem_device->res_list, list) {
		if (info->enabled) { /* just sanity check...*/
			num_enabled++;
			continue;
		}

		if (!info->length)
			continue;

		result = xen_hotadd_memory(pxm, info);
		if (result)
			continue;
		info->enabled = 1;
		num_enabled++;
	}

	if (!num_enabled)
		return -ENODEV;

	return 0;
}

static acpi_status
acpi_memory_get_resource(struct acpi_resource *resource, void *context)
{
	struct acpi_memory_device *mem_device = context;
	struct acpi_resource_address64 address64;
	struct acpi_memory_info *info, *new;
	acpi_status status;

	status = acpi_resource_to_address64(resource, &address64);
	if (ACPI_FAILURE(status) ||
	    (address64.resource_type != ACPI_MEMORY_RANGE))
		return AE_OK;

	list_for_each_entry(info, &mem_device->res_list, list) {
		if ((info->caching == address64.info.mem.caching) &&
		    (info->write_protect == address64.info.mem.write_protect) &&
		    (info->start_addr + info->length == address64.minimum)) {
			info->length += address64.address_length;
			return AE_OK;
		}
	}

	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	if (!new)
		return AE_ERROR;

	INIT_LIST_HEAD(&new->list);
	new->caching = address64.info.mem.caching;
	new->write_protect = address64.info.mem.write_protect;
	new->start_addr = address64.minimum;
	new->length = address64.address_length;
	list_add_tail(&new->list, &mem_device->res_list);

	return AE_OK;
}

static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
	acpi_status status;
	struct acpi_memory_info *info, *n;

	if (!list_empty(&mem_device->res_list))
		return 0;

	status = acpi_walk_resources(mem_device->device->handle,
		METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);

	if (ACPI_FAILURE(status)) {
		list_for_each_entry_safe(info, n, &mem_device->res_list, list)
			kfree(info);
		INIT_LIST_HEAD(&mem_device->res_list);
		return -EINVAL;
	}

	return 0;
}

static int acpi_memory_get_device(acpi_handle handle,
				  struct acpi_memory_device **mem_device)
{
	struct acpi_device *device = NULL;
	int result = 0;

	acpi_scan_lock_acquire();

	acpi_bus_get_device(handle, &device);
	if (device)
		goto end;

	/*
	 * Now add the notified device.  This creates the acpi_device
	 * and invokes .add function
	 */
	result = acpi_bus_scan(handle);
	if (result) {
		pr_warn(PREFIX "ACPI namespace scan failed\n");
		result = -EINVAL;
		goto out;
	}
	result = acpi_bus_get_device(handle, &device);
	if (result) {
		pr_warn(PREFIX "Missing device object\n");
		result = -EINVAL;
		goto out;
	}

end:
	*mem_device = acpi_driver_data(device);
	if (!(*mem_device)) {
		pr_err(PREFIX "driver data not found\n");
		result = -ENODEV;
		goto out;
	}

out:
	acpi_scan_lock_release();
	return result;
}

static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
{
	unsigned long long current_status;

	/* Get device present/absent information from the _STA */
	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
				"_STA", NULL, &current_status)))
		return -ENODEV;
	/*
	 * Check for device status. Device should be
	 * present/enabled/functioning.
	 */
	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
	      && (current_status & ACPI_STA_DEVICE_ENABLED)
	      && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
		return -ENODEV;

	return 0;
}

static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
{
	pr_debug(PREFIX "Xen does not support memory hotremove\n");

	return -ENOSYS;
}

static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
{
	struct acpi_memory_device *mem_device;
	struct acpi_device *device;
	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */

	switch (event) {
	case ACPI_NOTIFY_BUS_CHECK:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived BUS CHECK notification for device\n"));
		/* Fall Through */
	case ACPI_NOTIFY_DEVICE_CHECK:
		if (event == ACPI_NOTIFY_DEVICE_CHECK)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived DEVICE CHECK notification for device\n"));

		if (acpi_memory_get_device(handle, &mem_device)) {
			pr_err(PREFIX "Cannot find driver data\n");
			break;
		}

		ost_code = ACPI_OST_SC_SUCCESS;
		break;

	case ACPI_NOTIFY_EJECT_REQUEST:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived EJECT REQUEST notification for device\n"));

		acpi_scan_lock_acquire();
		if (acpi_bus_get_device(handle, &device)) {
			acpi_scan_lock_release();
			pr_err(PREFIX "Device doesn't exist\n");
			break;
		}
		mem_device = acpi_driver_data(device);
		if (!mem_device) {
			acpi_scan_lock_release();
			pr_err(PREFIX "Driver Data is NULL\n");
			break;
		}

		/*
		 * TBD: implement acpi_memory_disable_device and invoke
		 * acpi_bus_remove if Xen support hotremove in the future
		 */
		acpi_memory_disable_device(mem_device);
		acpi_scan_lock_release();
		break;

	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Unsupported event [0x%x]\n", event));
		/* non-hotplug event; possibly handled by other handler */
		return;
	}

	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
	return;
}

static int xen_acpi_memory_device_add(struct acpi_device *device)
{
	int result;
	struct acpi_memory_device *mem_device = NULL;


	if (!device)
		return -EINVAL;

	mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	if (!mem_device)
		return -ENOMEM;

	INIT_LIST_HEAD(&mem_device->res_list);
	mem_device->device = device;
	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	device->driver_data = mem_device;

	/* Get the range from the _CRS */
	result = acpi_memory_get_device_resources(mem_device);
	if (result) {
		kfree(mem_device);
		return result;
	}

	/*
	 * For booting existed memory devices, early boot code has recognized
	 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
	 * hotplug is not necessary for them.
	 * For hot-added memory devices during runtime, it need hypercall to
	 * Xen hypervisor to add memory.
	 */
	if (!acpi_hotmem_initialized)
		return 0;

	if (!acpi_memory_check_device(mem_device))
		result = xen_acpi_memory_enable_device(mem_device);

	return result;
}

static int xen_acpi_memory_device_remove(struct acpi_device *device)
{
	struct acpi_memory_device *mem_device = NULL;

	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	mem_device = acpi_driver_data(device);
	kfree(mem_device);

	return 0;
}

/*
 * Helper function to check for memory device
 */
static acpi_status is_memory_device(acpi_handle handle)
{
	char *hardware_id;
	acpi_status status;
	struct acpi_device_info *info;

	status = acpi_get_object_info(handle, &info);
	if (ACPI_FAILURE(status))
		return status;

	if (!(info->valid & ACPI_VALID_HID)) {
		kfree(info);
		return AE_ERROR;
	}

	hardware_id = info->hardware_id.string;
	if ((hardware_id == NULL) ||
	    (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
		status = AE_ERROR;

	kfree(info);
	return status;
}

static acpi_status
acpi_memory_register_notify_handler(acpi_handle handle,
				    u32 level, void *ctxt, void **retv)
{
	acpi_status status;

	status = is_memory_device(handle);
	if (ACPI_FAILURE(status))
		return AE_OK;	/* continue */

	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
					     acpi_memory_device_notify, NULL);
	/* continue */
	return AE_OK;
}

static acpi_status
acpi_memory_deregister_notify_handler(acpi_handle handle,
				      u32 level, void *ctxt, void **retv)
{
	acpi_status status;

	status = is_memory_device(handle);
	if (ACPI_FAILURE(status))
		return AE_OK;	/* continue */

	status = acpi_remove_notify_handler(handle,
					    ACPI_SYSTEM_NOTIFY,
					    acpi_memory_device_notify);

	return AE_OK;	/* continue */
}

static const struct acpi_device_id memory_device_ids[] = {
	{ACPI_MEMORY_DEVICE_HID, 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, memory_device_ids);

static struct acpi_driver xen_acpi_memory_device_driver = {
	.name = "acpi_memhotplug",
	.class = ACPI_MEMORY_DEVICE_CLASS,
	.ids = memory_device_ids,
	.ops = {
		.add = xen_acpi_memory_device_add,
		.remove = xen_acpi_memory_device_remove,
		},
};

static int __init xen_acpi_memory_device_init(void)
{
	int result;
	acpi_status status;

	if (!xen_initial_domain())
		return -ENODEV;

	/* unregister the stub which only used to reserve driver space */
	xen_stub_memory_device_exit();

	result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
	if (result < 0) {
		xen_stub_memory_device_init();
		return -ENODEV;
	}

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
				     ACPI_UINT32_MAX,
				     acpi_memory_register_notify_handler,
				     NULL, NULL, NULL);

	if (ACPI_FAILURE(status)) {
		pr_warn(PREFIX "walk_namespace failed\n");
		acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
		xen_stub_memory_device_init();
		return -ENODEV;
	}

	acpi_hotmem_initialized = true;
	return 0;
}

static void __exit xen_acpi_memory_device_exit(void)
{
	acpi_status status;

	if (!xen_initial_domain())
		return;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
				     ACPI_UINT32_MAX,
				     acpi_memory_deregister_notify_handler,
				     NULL, NULL, NULL);
	if (ACPI_FAILURE(status))
		pr_warn(PREFIX "walk_namespace failed\n");

	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);

	/*
	 * stub reserve space again to prevent any chance of native
	 * driver loading.
	 */
	xen_stub_memory_device_init();
	return;
}

module_init(xen_acpi_memory_device_init);
module_exit(xen_acpi_memory_device_exit);
ACPI_MODULE_NAME("xen-acpi-memhotplug");
MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
ef92e7ca LJ	1	/*
	2	* Copyright (C) 2012 Intel Corporation
	3	* Author: Liu Jinsong <jinsong.liu@intel.com>
	4	* Author: Jiang Yunhong <yunhong.jiang@intel.com>
	5	*
	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.
	10	*
	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
	15	* details.
	16	*/
	17
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/init.h>
	21	#include <linux/types.h>
	22	#include <linux/acpi.h>
	23	#include <acpi/acpi_drivers.h>
	24	#include <xen/acpi.h>
	25	#include <xen/interface/platform.h>
	26	#include <asm/xen/hypercall.h>
	27
	28	#define PREFIX "ACPI:xen_memory_hotplug:"
	29
	30	struct acpi_memory_info {
	31	struct list_head list;
	32	u64 start_addr; /* Memory Range start physical addr */
	33	u64 length; /* Memory Range length */
	34	unsigned short caching; /* memory cache attribute */
	35	unsigned short write_protect; /* memory read/write attribute */
	36	/* copied from buffer getting from _CRS */
	37	unsigned int enabled:1;
	38	};
	39
	40	struct acpi_memory_device {
	41	struct acpi_device *device;
	42	struct list_head res_list;
	43	};
	44
	45	static bool acpi_hotmem_initialized __read_mostly;
	46
	47	static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
	48	{
	49	int rc;
	50	struct xen_platform_op op;
	51
	52	op.cmd = XENPF_mem_hotadd;
	53	op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
	54	op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
	55	op.u.mem_add.pxm = pxm;
	56
	57	rc = HYPERVISOR_dom0_op(&op);
	58	if (rc)
	59	pr_err(PREFIX "Xen Hotplug Memory Add failed on "
	60	"0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
	61	(unsigned long)info->start_addr,
	62	(unsigned long)(info->start_addr + info->length),
	63	pxm, rc);
	64
65	return rc;
66	}
67
ef92e7ca LJ	68	static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
	69	{
	70	int pxm, result;
	71	int num_enabled = 0;
	72	struct acpi_memory_info *info;
	73
	74	if (!mem_device)
	75	return -EINVAL;
	76
	77	pxm = xen_acpi_get_pxm(mem_device->device->handle);
	78	if (pxm < 0)
	79	return pxm;
	80
	81	list_for_each_entry(info, &mem_device->res_list, list) {
	82	if (info->enabled) { /* just sanity check...*/
	83	num_enabled++;
	84	continue;
	85	}
	86
	87	if (!info->length)
	88	continue;
	89
	90	result = xen_hotadd_memory(pxm, info);
	91	if (result)
	92	continue;
	93	info->enabled = 1;
	94	num_enabled++;
	95	}
	96
	97	if (!num_enabled)
	98	return -ENODEV;
	99
	100	return 0;
	101	}
	102
	103	static acpi_status
	104	acpi_memory_get_resource(struct acpi_resource resource, void context)
	105	{
	106	struct acpi_memory_device *mem_device = context;
	107	struct acpi_resource_address64 address64;
	108	struct acpi_memory_info info, new;
	109	acpi_status status;
	110
	111	status = acpi_resource_to_address64(resource, &address64);
	112	if (ACPI_FAILURE(status) \|\|
	113	(address64.resource_type != ACPI_MEMORY_RANGE))
	114	return AE_OK;
	115
	116	list_for_each_entry(info, &mem_device->res_list, list) {
	117	if ((info->caching == address64.info.mem.caching) &&
	118	(info->write_protect == address64.info.mem.write_protect) &&
	119	(info->start_addr + info->length == address64.minimum)) {
	120	info->length += address64.address_length;
	121	return AE_OK;
	122	}
	123	}
	124
	125	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	126	if (!new)
	127	return AE_ERROR;
	128
	129	INIT_LIST_HEAD(&new->list);
	130	new->caching = address64.info.mem.caching;
	131	new->write_protect = address64.info.mem.write_protect;
132	new->start_addr = address64.minimum;
133	new->length = address64.address_length;
134	list_add_tail(&new->list, &mem_device->res_list);
135
136	return AE_OK;
137	}
138
139	static int
140	acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
141	{
142	acpi_status status;
143	struct acpi_memory_info info, n;
144
145	if (!list_empty(&mem_device->res_list))
146	return 0;
147
148	status = acpi_walk_resources(mem_device->device->handle,
149	METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
150
151	if (ACPI_FAILURE(status)) {
152	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
153	kfree(info);
154	INIT_LIST_HEAD(&mem_device->res_list);
155	return -EINVAL;
156	}
157
158	return 0;
159	}
160
484400ff LJ	161	static int acpi_memory_get_device(acpi_handle handle,
484400ff LJ	162	struct acpi_memory_device **mem_device)
ef92e7ca	163	{
ef92e7ca	164	struct acpi_device *device = NULL;
484400ff	165	int result = 0;
ef92e7ca	166
484400ff	167	acpi_scan_lock_acquire();
ef92e7ca	168
484400ff LJ	169	acpi_bus_get_device(handle, &device);
	170	if (device)
	171	goto end;
ef92e7ca LJ	172
	173	/*
	174	* Now add the notified device. This creates the acpi_device
	175	* and invokes .add function
	176	*/
77be36de	177	result = acpi_bus_scan(handle);
ef92e7ca	178	if (result) {
484400ff LJ	179	pr_warn(PREFIX "ACPI namespace scan failed\n");
	180	result = -EINVAL;
	181	goto out;
	182	}
	183	result = acpi_bus_get_device(handle, &device);
	184	if (result) {
	185	pr_warn(PREFIX "Missing device object\n");
	186	result = -EINVAL;
	187	goto out;
ef92e7ca LJ	188	}
	189
	190	end:
	191	*mem_device = acpi_driver_data(device);
	192	if (!(*mem_device)) {
484400ff LJ	193	pr_err(PREFIX "driver data not found\n");
	194	result = -ENODEV;
	195	goto out;
ef92e7ca LJ	196	}
ef92e7ca LJ	197
484400ff LJ	198	out:
	199	acpi_scan_lock_release();
	200	return result;
ef92e7ca LJ	201	}
	202
	203	static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
	204	{
	205	unsigned long long current_status;
	206
	207	/* Get device present/absent information from the _STA */
	208	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
	209	"_STA", NULL, &current_status)))
	210	return -ENODEV;
	211	/*
	212	* Check for device status. Device should be
	213	* present/enabled/functioning.
	214	*/
	215	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
	216	&& (current_status & ACPI_STA_DEVICE_ENABLED)
	217	&& (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
	218	return -ENODEV;
	219
	220	return 0;
	221	}
	222
	223	static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
	224	{
	225	pr_debug(PREFIX "Xen does not support memory hotremove\n");
	226
	227	return -ENOSYS;
	228	}
	229
	230	static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
	231	{
	232	struct acpi_memory_device *mem_device;
	233	struct acpi_device *device;
	234	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
	235
	236	switch (event) {
	237	case ACPI_NOTIFY_BUS_CHECK:
	238	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	239	"\nReceived BUS CHECK notification for device\n"));
	240	/* Fall Through */
	241	case ACPI_NOTIFY_DEVICE_CHECK:
	242	if (event == ACPI_NOTIFY_DEVICE_CHECK)
	243	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	244	"\nReceived DEVICE CHECK notification for device\n"));
	245
	246	if (acpi_memory_get_device(handle, &mem_device)) {
	247	pr_err(PREFIX "Cannot find driver data\n");
	248	break;
	249	}
	250
	251	ost_code = ACPI_OST_SC_SUCCESS;
	252	break;
	253
	254	case ACPI_NOTIFY_EJECT_REQUEST:
	255	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	256	"\nReceived EJECT REQUEST notification for device\n"));
	257
484400ff	258	acpi_scan_lock_acquire();
ef92e7ca	259	if (acpi_bus_get_device(handle, &device)) {
484400ff	260	acpi_scan_lock_release();
ef92e7ca LJ	261	pr_err(PREFIX "Device doesn't exist\n");
	262	break;
	263	}
	264	mem_device = acpi_driver_data(device);
	265	if (!mem_device) {
484400ff	266	acpi_scan_lock_release();
ef92e7ca LJ	267	pr_err(PREFIX "Driver Data is NULL\n");
	268	break;
	269	}
	270
	271	/*
	272	* TBD: implement acpi_memory_disable_device and invoke
	273	* acpi_bus_remove if Xen support hotremove in the future
	274	*/
	275	acpi_memory_disable_device(mem_device);
484400ff	276	acpi_scan_lock_release();
ef92e7ca LJ	277	break;
	278
	279	default:
	280	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	281	"Unsupported event [0x%x]\n", event));
	282	/* non-hotplug event; possibly handled by other handler */
	283	return;
	284	}
	285
	286	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
	287	return;
	288	}
	289
	290	static int xen_acpi_memory_device_add(struct acpi_device *device)
	291	{
	292	int result;
	293	struct acpi_memory_device *mem_device = NULL;
	294
	295
	296	if (!device)
	297	return -EINVAL;
	298
	299	mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	300	if (!mem_device)
	301	return -ENOMEM;
	302
	303	INIT_LIST_HEAD(&mem_device->res_list);
	304	mem_device->device = device;
	305	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	306	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	307	device->driver_data = mem_device;
	308
	309	/* Get the range from the _CRS */
	310	result = acpi_memory_get_device_resources(mem_device);
	311	if (result) {
	312	kfree(mem_device);
	313	return result;
	314	}
	315
	316	/*
	317	* For booting existed memory devices, early boot code has recognized
	318	* memory area by EFI/E820. If DSDT shows these memory devices on boot,
	319	* hotplug is not necessary for them.
	320	* For hot-added memory devices during runtime, it need hypercall to
	321	* Xen hypervisor to add memory.
	322	*/
	323	if (!acpi_hotmem_initialized)
	324	return 0;
	325
	326	if (!acpi_memory_check_device(mem_device))
	327	result = xen_acpi_memory_enable_device(mem_device);
	328
	329	return result;
	330	}
	331
77be36de	332	static int xen_acpi_memory_device_remove(struct acpi_device *device)
ef92e7ca LJ	333	{
	334	struct acpi_memory_device *mem_device = NULL;
	335
	336	if (!device \|\| !acpi_driver_data(device))
	337	return -EINVAL;
	338
	339	mem_device = acpi_driver_data(device);
	340	kfree(mem_device);
	341
	342	return 0;
	343	}
	344
	345	/*
	346	* Helper function to check for memory device
	347	*/
	348	static acpi_status is_memory_device(acpi_handle handle)
	349	{
	350	char *hardware_id;
	351	acpi_status status;
	352	struct acpi_device_info *info;
	353
	354	status = acpi_get_object_info(handle, &info);
	355	if (ACPI_FAILURE(status))
	356	return status;
	357
	358	if (!(info->valid & ACPI_VALID_HID)) {
	359	kfree(info);
	360	return AE_ERROR;
	361	}
	362
	363	hardware_id = info->hardware_id.string;
	364	if ((hardware_id == NULL) \|\|
	365	(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
	366	status = AE_ERROR;
	367
	368	kfree(info);
	369	return status;
	370	}
	371
	372	static acpi_status
	373	acpi_memory_register_notify_handler(acpi_handle handle,
	374	u32 level, void ctxt, void *retv)
	375	{
	376	acpi_status status;
	377
	378	status = is_memory_device(handle);
	379	if (ACPI_FAILURE(status))
	380	return AE_OK; /* continue */
	381
	382	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
	383	acpi_memory_device_notify, NULL);
	384	/* continue */
	385	return AE_OK;
	386	}
	387
	388	static acpi_status
	389	acpi_memory_deregister_notify_handler(acpi_handle handle,
	390	u32 level, void ctxt, void *retv)
	391	{
	392	acpi_status status;
	393
	394	status = is_memory_device(handle);
	395	if (ACPI_FAILURE(status))
	396	return AE_OK; /* continue */
397
398	status = acpi_remove_notify_handler(handle,
399	ACPI_SYSTEM_NOTIFY,
400	acpi_memory_device_notify);
401
402	return AE_OK; /* continue */
403	}
404
405	static const struct acpi_device_id memory_device_ids[] = {
406	{ACPI_MEMORY_DEVICE_HID, 0},
407	{"", 0},
408	};
409	MODULE_DEVICE_TABLE(acpi, memory_device_ids);
410
411	static struct acpi_driver xen_acpi_memory_device_driver = {
412	.name = "acpi_memhotplug",
413	.class = ACPI_MEMORY_DEVICE_CLASS,
414	.ids = memory_device_ids,
415	.ops = {
416	.add = xen_acpi_memory_device_add,
417	.remove = xen_acpi_memory_device_remove,
418	},
419	};
420
421	static int __init xen_acpi_memory_device_init(void)
422	{
423	int result;
424	acpi_status status;
425
426	if (!xen_initial_domain())
427	return -ENODEV;
428
429	/* unregister the stub which only used to reserve driver space */
430	xen_stub_memory_device_exit();
431
432	result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
433	if (result < 0) {
434	xen_stub_memory_device_init();
435	return -ENODEV;
436	}
437
438	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
439	ACPI_UINT32_MAX,
440	acpi_memory_register_notify_handler,
441	NULL, NULL, NULL);
442
443	if (ACPI_FAILURE(status)) {
444	pr_warn(PREFIX "walk_namespace failed\n");
445	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
446	xen_stub_memory_device_init();
447	return -ENODEV;
448	}
449
450	acpi_hotmem_initialized = true;
451	return 0;
452	}
453
454	static void __exit xen_acpi_memory_device_exit(void)
455	{
456	acpi_status status;
457
458	if (!xen_initial_domain())
459	return;
460
461	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
462	ACPI_UINT32_MAX,
463	acpi_memory_deregister_notify_handler,
464	NULL, NULL, NULL);
465	if (ACPI_FAILURE(status))
466	pr_warn(PREFIX "walk_namespace failed\n");
467
468	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
469
470	/*
471	* stub reserve space again to prevent any chance of native
472	* driver loading.
473	*/
474	xen_stub_memory_device_init();
475	return;
476	}
477
478	module_init(xen_acpi_memory_device_init);
479	module_exit(xen_acpi_memory_device_exit);
480	ACPI_MODULE_NAME("xen-acpi-memhotplug");
481	MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
482	MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
483	MODULE_LICENSE("GPL");