[thirdparty/linux.git] / drivers / xen / xen-acpi-memhotplug.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2012 Intel Corporation
 *    Author: Liu Jinsong <jinsong.liu@intel.com>
 *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.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.address.minimum)) {
			info->length += address64.address.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.address.minimum;
	new->length = address64.address.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 (acpi_device_enumerated(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;
	}
	device = NULL;
	acpi_bus_get_device(handle, &device);
	if (!acpi_device_enumerated(device)) {
		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_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
4359375c	1	// SPDX-License-Identifier: GPL-2.0-or-later
ef92e7ca LJ	2	/*
	3	* Copyright (C) 2012 Intel Corporation
	4	* Author: Liu Jinsong <jinsong.liu@intel.com>
	5	* Author: Jiang Yunhong <yunhong.jiang@intel.com>
ef92e7ca LJ	6	*/
ef92e7ca LJ	7
283c0972 JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
283c0972 JP	9
ef92e7ca LJ	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/types.h>
	14	#include <linux/acpi.h>
ef92e7ca LJ	15	#include <xen/acpi.h>
	16	#include <xen/interface/platform.h>
	17	#include <asm/xen/hypercall.h>
	18
	19	#define PREFIX "ACPI:xen_memory_hotplug:"
	20
	21	struct acpi_memory_info {
	22	struct list_head list;
	23	u64 start_addr; /* Memory Range start physical addr */
	24	u64 length; /* Memory Range length */
	25	unsigned short caching; /* memory cache attribute */
	26	unsigned short write_protect; /* memory read/write attribute */
	27	/* copied from buffer getting from _CRS */
	28	unsigned int enabled:1;
	29	};
	30
	31	struct acpi_memory_device {
	32	struct acpi_device *device;
	33	struct list_head res_list;
	34	};
	35
	36	static bool acpi_hotmem_initialized __read_mostly;
	37
	38	static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
	39	{
	40	int rc;
	41	struct xen_platform_op op;
	42
	43	op.cmd = XENPF_mem_hotadd;
	44	op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
	45	op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
	46	op.u.mem_add.pxm = pxm;
	47
	48	rc = HYPERVISOR_dom0_op(&op);
	49	if (rc)
	50	pr_err(PREFIX "Xen Hotplug Memory Add failed on "
	51	"0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
	52	(unsigned long)info->start_addr,
	53	(unsigned long)(info->start_addr + info->length),
	54	pxm, rc);
	55
	56	return rc;
	57	}
	58
ef92e7ca LJ	59	static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
	60	{
	61	int pxm, result;
	62	int num_enabled = 0;
	63	struct acpi_memory_info *info;
	64
	65	if (!mem_device)
	66	return -EINVAL;
	67
	68	pxm = xen_acpi_get_pxm(mem_device->device->handle);
	69	if (pxm < 0)
	70	return pxm;
	71
	72	list_for_each_entry(info, &mem_device->res_list, list) {
	73	if (info->enabled) { /* just sanity check...*/
	74	num_enabled++;
	75	continue;
	76	}
	77
	78	if (!info->length)
	79	continue;
	80
	81	result = xen_hotadd_memory(pxm, info);
	82	if (result)
	83	continue;
	84	info->enabled = 1;
	85	num_enabled++;
	86	}
	87
	88	if (!num_enabled)
	89	return -ENODEV;
	90
	91	return 0;
	92	}
	93
	94	static acpi_status
	95	acpi_memory_get_resource(struct acpi_resource resource, void context)
	96	{
	97	struct acpi_memory_device *mem_device = context;
	98	struct acpi_resource_address64 address64;
	99	struct acpi_memory_info info, new;
	100	acpi_status status;
	101
	102	status = acpi_resource_to_address64(resource, &address64);
	103	if (ACPI_FAILURE(status) \|\|
	104	(address64.resource_type != ACPI_MEMORY_RANGE))
	105	return AE_OK;
	106
	107	list_for_each_entry(info, &mem_device->res_list, list) {
	108	if ((info->caching == address64.info.mem.caching) &&
	109	(info->write_protect == address64.info.mem.write_protect) &&
a45de93e LZ	110	(info->start_addr + info->length == address64.address.minimum)) {
a45de93e LZ	111	info->length += address64.address.address_length;
ef92e7ca LJ	112	return AE_OK;
	113	}
	114	}
	115
	116	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	117	if (!new)
	118	return AE_ERROR;
	119
	120	INIT_LIST_HEAD(&new->list);
	121	new->caching = address64.info.mem.caching;
	122	new->write_protect = address64.info.mem.write_protect;
a45de93e LZ	123	new->start_addr = address64.address.minimum;
a45de93e LZ	124	new->length = address64.address.address_length;
ef92e7ca LJ	125	list_add_tail(&new->list, &mem_device->res_list);
	126
	127	return AE_OK;
	128	}
	129
	130	static int
	131	acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
	132	{
	133	acpi_status status;
	134	struct acpi_memory_info info, n;
	135
	136	if (!list_empty(&mem_device->res_list))
	137	return 0;
	138
	139	status = acpi_walk_resources(mem_device->device->handle,
	140	METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
	141
	142	if (ACPI_FAILURE(status)) {
	143	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
	144	kfree(info);
	145	INIT_LIST_HEAD(&mem_device->res_list);
	146	return -EINVAL;
	147	}
	148
	149	return 0;
	150	}
	151
484400ff LJ	152	static int acpi_memory_get_device(acpi_handle handle,
484400ff LJ	153	struct acpi_memory_device **mem_device)
ef92e7ca	154	{
ef92e7ca	155	struct acpi_device *device = NULL;
484400ff	156	int result = 0;
ef92e7ca	157
484400ff	158	acpi_scan_lock_acquire();
ef92e7ca	159
484400ff	160	acpi_bus_get_device(handle, &device);
202317a5	161	if (acpi_device_enumerated(device))
484400ff	162	goto end;
ef92e7ca LJ	163
	164	/*
	165	* Now add the notified device. This creates the acpi_device
	166	* and invokes .add function
	167	*/
77be36de	168	result = acpi_bus_scan(handle);
ef92e7ca	169	if (result) {
484400ff LJ	170	pr_warn(PREFIX "ACPI namespace scan failed\n");
	171	result = -EINVAL;
	172	goto out;
	173	}
202317a5 RW	174	device = NULL;
	175	acpi_bus_get_device(handle, &device);
	176	if (!acpi_device_enumerated(device)) {
484400ff LJ	177	pr_warn(PREFIX "Missing device object\n");
	178	result = -EINVAL;
	179	goto out;
ef92e7ca LJ	180	}
	181
	182	end:
	183	*mem_device = acpi_driver_data(device);
	184	if (!(*mem_device)) {
484400ff LJ	185	pr_err(PREFIX "driver data not found\n");
	186	result = -ENODEV;
	187	goto out;
ef92e7ca LJ	188	}
ef92e7ca LJ	189
484400ff LJ	190	out:
	191	acpi_scan_lock_release();
	192	return result;
ef92e7ca LJ	193	}
	194
	195	static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
	196	{
	197	unsigned long long current_status;
	198
	199	/* Get device present/absent information from the _STA */
	200	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
	201	"_STA", NULL, &current_status)))
	202	return -ENODEV;
	203	/*
	204	* Check for device status. Device should be
	205	* present/enabled/functioning.
	206	*/
	207	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
	208	&& (current_status & ACPI_STA_DEVICE_ENABLED)
	209	&& (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
	210	return -ENODEV;
	211
	212	return 0;
	213	}
	214
	215	static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
	216	{
	217	pr_debug(PREFIX "Xen does not support memory hotremove\n");
	218
	219	return -ENOSYS;
	220	}
	221
	222	static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
	223	{
	224	struct acpi_memory_device *mem_device;
	225	struct acpi_device *device;
	226	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
	227
	228	switch (event) {
	229	case ACPI_NOTIFY_BUS_CHECK:
	230	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	231	"\nReceived BUS CHECK notification for device\n"));
	232	/* Fall Through */
	233	case ACPI_NOTIFY_DEVICE_CHECK:
	234	if (event == ACPI_NOTIFY_DEVICE_CHECK)
	235	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	236	"\nReceived DEVICE CHECK notification for device\n"));
	237
	238	if (acpi_memory_get_device(handle, &mem_device)) {
	239	pr_err(PREFIX "Cannot find driver data\n");
	240	break;
	241	}
	242
	243	ost_code = ACPI_OST_SC_SUCCESS;
	244	break;
	245
	246	case ACPI_NOTIFY_EJECT_REQUEST:
	247	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	248	"\nReceived EJECT REQUEST notification for device\n"));
	249
484400ff	250	acpi_scan_lock_acquire();
ef92e7ca	251	if (acpi_bus_get_device(handle, &device)) {
484400ff	252	acpi_scan_lock_release();
ef92e7ca LJ	253	pr_err(PREFIX "Device doesn't exist\n");
	254	break;
	255	}
	256	mem_device = acpi_driver_data(device);
	257	if (!mem_device) {
484400ff	258	acpi_scan_lock_release();
ef92e7ca LJ	259	pr_err(PREFIX "Driver Data is NULL\n");
	260	break;
	261	}
	262
	263	/*
	264	* TBD: implement acpi_memory_disable_device and invoke
	265	* acpi_bus_remove if Xen support hotremove in the future
	266	*/
	267	acpi_memory_disable_device(mem_device);
484400ff	268	acpi_scan_lock_release();
ef92e7ca LJ	269	break;
	270
	271	default:
	272	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	273	"Unsupported event [0x%x]\n", event));
	274	/* non-hotplug event; possibly handled by other handler */
	275	return;
	276	}
	277
700b8422	278	(void) acpi_evaluate_ost(handle, event, ost_code, NULL);
ef92e7ca LJ	279	return;
	280	}
	281
	282	static int xen_acpi_memory_device_add(struct acpi_device *device)
	283	{
	284	int result;
	285	struct acpi_memory_device *mem_device = NULL;
	286
	287
	288	if (!device)
	289	return -EINVAL;
	290
	291	mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	292	if (!mem_device)
	293	return -ENOMEM;
	294
	295	INIT_LIST_HEAD(&mem_device->res_list);
	296	mem_device->device = device;
	297	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	298	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	299	device->driver_data = mem_device;
	300
	301	/* Get the range from the _CRS */
	302	result = acpi_memory_get_device_resources(mem_device);
	303	if (result) {
	304	kfree(mem_device);
	305	return result;
	306	}
	307
	308	/*
	309	* For booting existed memory devices, early boot code has recognized
	310	* memory area by EFI/E820. If DSDT shows these memory devices on boot,
	311	* hotplug is not necessary for them.
	312	* For hot-added memory devices during runtime, it need hypercall to
	313	* Xen hypervisor to add memory.
	314	*/
	315	if (!acpi_hotmem_initialized)
	316	return 0;
	317
	318	if (!acpi_memory_check_device(mem_device))
	319	result = xen_acpi_memory_enable_device(mem_device);
	320
	321	return result;
	322	}
	323
77be36de	324	static int xen_acpi_memory_device_remove(struct acpi_device *device)
ef92e7ca LJ	325	{
	326	struct acpi_memory_device *mem_device = NULL;
	327
	328	if (!device \|\| !acpi_driver_data(device))
	329	return -EINVAL;
	330
	331	mem_device = acpi_driver_data(device);
	332	kfree(mem_device);
	333
	334	return 0;
	335	}
	336
	337	/*
	338	* Helper function to check for memory device
	339	*/
	340	static acpi_status is_memory_device(acpi_handle handle)
	341	{
	342	char *hardware_id;
	343	acpi_status status;
	344	struct acpi_device_info *info;
	345
	346	status = acpi_get_object_info(handle, &info);
	347	if (ACPI_FAILURE(status))
	348	return status;
	349
	350	if (!(info->valid & ACPI_VALID_HID)) {
	351	kfree(info);
	352	return AE_ERROR;
	353	}
	354
	355	hardware_id = info->hardware_id.string;
	356	if ((hardware_id == NULL) \|\|
	357	(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
	358	status = AE_ERROR;
	359
	360	kfree(info);
	361	return status;
	362	}
	363
	364	static acpi_status
	365	acpi_memory_register_notify_handler(acpi_handle handle,
	366	u32 level, void ctxt, void *retv)
	367	{
	368	acpi_status status;
	369
	370	status = is_memory_device(handle);
	371	if (ACPI_FAILURE(status))
	372	return AE_OK; /* continue */
	373
	374	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
	375	acpi_memory_device_notify, NULL);
	376	/* continue */
	377	return AE_OK;
	378	}
	379
	380	static acpi_status
	381	acpi_memory_deregister_notify_handler(acpi_handle handle,
	382	u32 level, void ctxt, void *retv)
	383	{
	384	acpi_status status;
	385
	386	status = is_memory_device(handle);
	387	if (ACPI_FAILURE(status))
	388	return AE_OK; /* continue */
389
390	status = acpi_remove_notify_handler(handle,
391	ACPI_SYSTEM_NOTIFY,
392	acpi_memory_device_notify);
393
394	return AE_OK; /* continue */
395	}
396
397	static const struct acpi_device_id memory_device_ids[] = {
398	{ACPI_MEMORY_DEVICE_HID, 0},
399	{"", 0},
400	};
401	MODULE_DEVICE_TABLE(acpi, memory_device_ids);
402
403	static struct acpi_driver xen_acpi_memory_device_driver = {
404	.name = "acpi_memhotplug",
405	.class = ACPI_MEMORY_DEVICE_CLASS,
406	.ids = memory_device_ids,
407	.ops = {
408	.add = xen_acpi_memory_device_add,
409	.remove = xen_acpi_memory_device_remove,
410	},
411	};
412
413	static int __init xen_acpi_memory_device_init(void)
414	{
415	int result;
416	acpi_status status;
417
418	if (!xen_initial_domain())
419	return -ENODEV;
420
421	/* unregister the stub which only used to reserve driver space */
422	xen_stub_memory_device_exit();
423
424	result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
425	if (result < 0) {
426	xen_stub_memory_device_init();
427	return -ENODEV;
428	}
429
430	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
431	ACPI_UINT32_MAX,
432	acpi_memory_register_notify_handler,
433	NULL, NULL, NULL);
434
435	if (ACPI_FAILURE(status)) {
436	pr_warn(PREFIX "walk_namespace failed\n");
437	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
438	xen_stub_memory_device_init();
439	return -ENODEV;
440	}
441
442	acpi_hotmem_initialized = true;
443	return 0;
444	}
445
446	static void __exit xen_acpi_memory_device_exit(void)
447	{
448	acpi_status status;
449
450	if (!xen_initial_domain())
451	return;
452
453	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
454	ACPI_UINT32_MAX,
455	acpi_memory_deregister_notify_handler,
456	NULL, NULL, NULL);
457	if (ACPI_FAILURE(status))
458	pr_warn(PREFIX "walk_namespace failed\n");
459
460	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
461
462	/*
463	* stub reserve space again to prevent any chance of native
464	* driver loading.
465	*/
466	xen_stub_memory_device_init();
467	return;
468	}
469
470	module_init(xen_acpi_memory_device_init);
471	module_exit(xen_acpi_memory_device_exit);
472	ACPI_MODULE_NAME("xen-acpi-memhotplug");
473	MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
474	MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
475	MODULE_LICENSE("GPL");