xen/acpi: ACPI cpu hotplug

This patch implement real Xen ACPI cpu hotplug driver as module. When loaded, it replaces Xen stub driver. For booting existed cpus, the driver enumerates them. For hotadded cpus, which added at runtime and notify OS via device or container event, the driver is invoked to add them, parsing cpu information, hypercalling to Xen hypervisor to add them, and finally setting up new /sys interface for them. Signed-off-by: Liu Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen/acpi: ACPI cpu hotplug
This patch implement real Xen ACPI cpu hotplug driver as module. When loaded, it replaces Xen stub driver. For booting existed cpus, the driver enumerates them. For hotadded cpus, which added at runtime and notify OS via device or container event, the driver is invoked to add them, parsing cpu information, hypercalling to Xen hypervisor to add them, and finally setting up new /sys interface for them. Signed-off-by: Liu Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Liu Jinsong · Konrad Rzeszutek Wilk
1 parent 40a58637a4
Showing 6 changed files with 530 additions and 0 deletions Side-by-side Diff
drivers/xen/Kconfig
drivers/xen/Makefile
drivers/xen/pcpu.c
drivers/xen/xen-acpi-cpuhotplug.c
include/xen/acpi.h
include/xen/interface/platform.h
@@ -202,6 +202,18 @@
 	  to hot-add memory at runtime (the hot-added memory cannot be
 	  removed until machine stop), select Y/M here, otherwise select N.
  
+config XEN_ACPI_HOTPLUG_CPU
+	tristate "Xen ACPI cpu hotplug"
+	depends on XEN_DOM0 && XEN_STUB && ACPI
+	select ACPI_CONTAINER
+	default n
+	help
+	  Xen ACPI cpu enumerating and hotplugging
+
+	  For hotplugging, currently Xen only support ACPI cpu hotadd.
+	  If you want to hotadd cpu at runtime (the hotadded cpu cannot
+	  be removed until machine stop), select Y/M here.
+
 config XEN_ACPI_PROCESSOR
 	tristate "Xen ACPI processor"
 	depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
@@ -32,6 +32,7 @@
 obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
 obj-$(CONFIG_XEN_STUB)			+= xen-stub.o
 obj-$(CONFIG_XEN_ACPI_HOTPLUG_MEMORY)	+= xen-acpi-memhotplug.o
+obj-$(CONFIG_XEN_ACPI_HOTPLUG_CPU)	+= xen-acpi-cpuhotplug.o
 obj-$(CONFIG_XEN_ACPI_PROCESSOR)	+= xen-acpi-processor.o
 xen-evtchn-y				:= evtchn.o
 xen-gntdev-y				:= gntdev.o
@@ -333,6 +333,41 @@
 	return IRQ_HANDLED;
 }
  
+/* Sync with Xen hypervisor after cpu hotadded */
+void xen_pcpu_hotplug_sync(void)
+{
+	schedule_work(&xen_pcpu_work);
+}
+EXPORT_SYMBOL_GPL(xen_pcpu_hotplug_sync);
+
+/*
+ * For hypervisor presented cpu, return logic cpu id;
+ * For hypervisor non-presented cpu, return -ENODEV.
+ */
+int xen_pcpu_id(uint32_t acpi_id)
+{
+	int cpu_id = 0, max_id = 0;
+	struct xen_platform_op op;
+
+	op.cmd = XENPF_get_cpuinfo;
+	while (cpu_id <= max_id) {
+		op.u.pcpu_info.xen_cpuid = cpu_id;
+		if (HYPERVISOR_dom0_op(&op)) {
+			cpu_id++;
+			continue;
+		}
+
+		if (acpi_id == op.u.pcpu_info.acpi_id)
+			return cpu_id;
+		if (op.u.pcpu_info.max_present > max_id)
+			max_id = op.u.pcpu_info.max_present;
+		cpu_id++;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(xen_pcpu_id);
+
 static int __init xen_pcpu_init(void)
 {
 	int irq, ret;
+/*
+ * 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/cpu.h>
+#include <linux/acpi.h>
+#include <linux/uaccess.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/processor.h>
+
+#include <xen/acpi.h>
+#include <xen/interface/platform.h>
+#include <asm/xen/hypercall.h>
+
+#define PREFIX "ACPI:xen_cpu_hotplug:"
+
+#define INSTALL_NOTIFY_HANDLER		0
+#define UNINSTALL_NOTIFY_HANDLER	1
+
+static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr);
+
+/* --------------------------------------------------------------------------
+				Driver Interface
+-------------------------------------------------------------------------- */
+
+static int xen_acpi_processor_enable(struct acpi_device *device)
+{
+	acpi_status status = 0;
+	unsigned long long value;
+	union acpi_object object = { 0 };
+	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+	struct acpi_processor *pr;
+
+	pr = acpi_driver_data(device);
+	if (!pr) {
+		pr_err(PREFIX "Cannot find driver data\n");
+		return -EINVAL;
+	}
+
+	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
+		/* Declared with "Processor" statement; match ProcessorID */
+		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
+		if (ACPI_FAILURE(status)) {
+			pr_err(PREFIX "Evaluating processor object\n");
+			return -ENODEV;
+		}
+
+		pr->acpi_id = object.processor.proc_id;
+	} else {
+		/* Declared with "Device" statement; match _UID */
+		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
+						NULL, &value);
+		if (ACPI_FAILURE(status)) {
+			pr_err(PREFIX "Evaluating processor _UID\n");
+			return -ENODEV;
+		}
+
+		pr->acpi_id = value;
+	}
+
+	pr->id = xen_pcpu_id(pr->acpi_id);
+
+	if ((int)pr->id < 0)
+		/* This cpu is not presented at hypervisor, try to hotadd it */
+		if (ACPI_FAILURE(xen_acpi_cpu_hotadd(pr))) {
+			pr_err(PREFIX "Hotadd CPU (acpi_id = %d) failed.\n",
+					pr->acpi_id);
+			return -ENODEV;
+		}
+
+	return 0;
+}
+
+static int __cpuinit xen_acpi_processor_add(struct acpi_device *device)
+{
+	int ret;
+	struct acpi_processor *pr;
+
+	if (!device)
+		return -EINVAL;
+
+	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
+	if (!pr)
+		return -ENOMEM;
+
+	pr->handle = device->handle;
+	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
+	device->driver_data = pr;
+
+	ret = xen_acpi_processor_enable(device);
+	if (ret)
+		pr_err(PREFIX "Error when enabling Xen processor\n");
+
+	return ret;
+}
+
+static int xen_acpi_processor_remove(struct acpi_device *device, int type)
+{
+	struct acpi_processor *pr;
+
+	if (!device)
+		return -EINVAL;
+
+	pr = acpi_driver_data(device);
+	if (!pr)
+		return -EINVAL;
+
+	kfree(pr);
+	return 0;
+}
+
+/*--------------------------------------------------------------
+		Acpi processor hotplug support
+--------------------------------------------------------------*/
+
+static int is_processor_present(acpi_handle handle)
+{
+	acpi_status status;
+	unsigned long long sta = 0;
+
+
+	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+
+	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
+		return 1;
+
+	/*
+	 * _STA is mandatory for a processor that supports hot plug
+	 */
+	if (status == AE_NOT_FOUND)
+		pr_info(PREFIX "Processor does not support hot plug\n");
+	else
+		pr_info(PREFIX "Processor Device is not present");
+	return 0;
+}
+
+static int xen_apic_id(acpi_handle handle)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	struct acpi_madt_local_apic *lapic;
+	int apic_id;
+
+	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
+		return -EINVAL;
+
+	if (!buffer.length || !buffer.pointer)
+		return -EINVAL;
+
+	obj = buffer.pointer;
+	if (obj->type != ACPI_TYPE_BUFFER ||
+	    obj->buffer.length < sizeof(*lapic)) {
+		kfree(buffer.pointer);
+		return -EINVAL;
+	}
+
+	lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
+
+	if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
+	    !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
+		kfree(buffer.pointer);
+		return -EINVAL;
+	}
+
+	apic_id = (uint32_t)lapic->id;
+	kfree(buffer.pointer);
+	buffer.length = ACPI_ALLOCATE_BUFFER;
+	buffer.pointer = NULL;
+
+	return apic_id;
+}
+
+static int xen_hotadd_cpu(struct acpi_processor *pr)
+{
+	int cpu_id, apic_id, pxm;
+	struct xen_platform_op op;
+
+	apic_id = xen_apic_id(pr->handle);
+	if (apic_id < 0) {
+		pr_err(PREFIX "Failed to get apic_id for acpi_id %d\n",
+				pr->acpi_id);
+		return -ENODEV;
+	}
+
+	pxm = xen_acpi_get_pxm(pr->handle);
+	if (pxm < 0) {
+		pr_err(PREFIX "Failed to get _PXM for acpi_id %d\n",
+				pr->acpi_id);
+		return pxm;
+	}
+
+	op.cmd = XENPF_cpu_hotadd;
+	op.u.cpu_add.apic_id = apic_id;
+	op.u.cpu_add.acpi_id = pr->acpi_id;
+	op.u.cpu_add.pxm = pxm;
+
+	cpu_id = HYPERVISOR_dom0_op(&op);
+	if (cpu_id < 0)
+		pr_err(PREFIX "Failed to hotadd CPU for acpi_id %d\n",
+				pr->acpi_id);
+
+	return cpu_id;
+}
+
+static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr)
+{
+	if (!is_processor_present(pr->handle))
+		return AE_ERROR;
+
+	pr->id = xen_hotadd_cpu(pr);
+	if ((int)pr->id < 0)
+		return AE_ERROR;
+
+	/*
+	 * Sync with Xen hypervisor, providing new /sys/.../xen_cpuX
+	 * interface after cpu hotadded.
+	 */
+	xen_pcpu_hotplug_sync();
+
+	return AE_OK;
+}
+
+static
+int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
+{
+	acpi_handle phandle;
+	struct acpi_device *pdev;
+
+	if (acpi_get_parent(handle, &phandle))
+		return -ENODEV;
+
+	if (acpi_bus_get_device(phandle, &pdev))
+		return -ENODEV;
+
+	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int acpi_processor_device_remove(struct acpi_device *device)
+{
+	pr_debug(PREFIX "Xen does not support CPU hotremove\n");
+
+	return -ENOSYS;
+}
+
+static void acpi_processor_hotplug_notify(acpi_handle handle,
+					  u32 event, void *data)
+{
+	struct acpi_processor *pr;
+	struct acpi_device *device = NULL;
+	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
+	int result;
+
+	switch (event) {
+	case ACPI_NOTIFY_BUS_CHECK:
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			"Processor driver received %s event\n",
+			(event == ACPI_NOTIFY_BUS_CHECK) ?
+			"ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
+
+		if (!is_processor_present(handle))
+			break;
+
+		if (!acpi_bus_get_device(handle, &device))
+			break;
+
+		result = acpi_processor_device_add(handle, &device);
+		if (result) {
+			pr_err(PREFIX "Unable to add the device\n");
+			break;
+		}
+
+		ost_code = ACPI_OST_SC_SUCCESS;
+		break;
+
+	case ACPI_NOTIFY_EJECT_REQUEST:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
+
+		if (acpi_bus_get_device(handle, &device)) {
+			pr_err(PREFIX "Device don't exist, dropping EJECT\n");
+			break;
+		}
+		pr = acpi_driver_data(device);
+		if (!pr) {
+			pr_err(PREFIX "Driver data is NULL, dropping EJECT\n");
+			break;
+		}
+
+		/*
+		 * TBD: implement acpi_processor_device_remove if Xen support
+		 * CPU hotremove in the future.
+		 */
+		acpi_processor_device_remove(device);
+		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 acpi_status is_processor_device(acpi_handle handle)
+{
+	struct acpi_device_info *info;
+	char *hid;
+	acpi_status status;
+
+	status = acpi_get_object_info(handle, &info);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	if (info->type == ACPI_TYPE_PROCESSOR) {
+		kfree(info);
+		return AE_OK;	/* found a processor object */
+	}
+
+	if (!(info->valid & ACPI_VALID_HID)) {
+		kfree(info);
+		return AE_ERROR;
+	}
+
+	hid = info->hardware_id.string;
+	if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
+		kfree(info);
+		return AE_ERROR;
+	}
+
+	kfree(info);
+	return AE_OK;	/* found a processor device object */
+}
+
+static acpi_status
+processor_walk_namespace_cb(acpi_handle handle,
+			    u32 lvl, void *context, void **rv)
+{
+	acpi_status status;
+	int *action = context;
+
+	status = is_processor_device(handle);
+	if (ACPI_FAILURE(status))
+		return AE_OK;	/* not a processor; continue to walk */
+
+	switch (*action) {
+	case INSTALL_NOTIFY_HANDLER:
+		acpi_install_notify_handler(handle,
+					    ACPI_SYSTEM_NOTIFY,
+					    acpi_processor_hotplug_notify,
+					    NULL);
+		break;
+	case UNINSTALL_NOTIFY_HANDLER:
+		acpi_remove_notify_handler(handle,
+					   ACPI_SYSTEM_NOTIFY,
+					   acpi_processor_hotplug_notify);
+		break;
+	default:
+		break;
+	}
+
+	/* found a processor; skip walking underneath */
+	return AE_CTRL_DEPTH;
+}
+
+static
+void acpi_processor_install_hotplug_notify(void)
+{
+	int action = INSTALL_NOTIFY_HANDLER;
+	acpi_walk_namespace(ACPI_TYPE_ANY,
+			    ACPI_ROOT_OBJECT,
+			    ACPI_UINT32_MAX,
+			    processor_walk_namespace_cb, NULL, &action, NULL);
+}
+
+static
+void acpi_processor_uninstall_hotplug_notify(void)
+{
+	int action = UNINSTALL_NOTIFY_HANDLER;
+	acpi_walk_namespace(ACPI_TYPE_ANY,
+			    ACPI_ROOT_OBJECT,
+			    ACPI_UINT32_MAX,
+			    processor_walk_namespace_cb, NULL, &action, NULL);
+}
+
+static const struct acpi_device_id processor_device_ids[] = {
+	{ACPI_PROCESSOR_OBJECT_HID, 0},
+	{ACPI_PROCESSOR_DEVICE_HID, 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, processor_device_ids);
+
+static struct acpi_driver xen_acpi_processor_driver = {
+	.name = "processor",
+	.class = ACPI_PROCESSOR_CLASS,
+	.ids = processor_device_ids,
+	.ops = {
+		.add = xen_acpi_processor_add,
+		.remove = xen_acpi_processor_remove,
+		},
+};
+
+static int __init xen_acpi_processor_init(void)
+{
+	int result = 0;
+
+	if (!xen_initial_domain())
+		return -ENODEV;
+
+	/* unregister the stub which only used to reserve driver space */
+	xen_stub_processor_exit();
+
+	result = acpi_bus_register_driver(&xen_acpi_processor_driver);
+	if (result < 0) {
+		xen_stub_processor_init();
+		return result;
+	}
+
+	acpi_processor_install_hotplug_notify();
+	return 0;
+}
+
+static void __exit xen_acpi_processor_exit(void)
+{
+	if (!xen_initial_domain())
+		return;
+
+	acpi_processor_uninstall_hotplug_notify();
+
+	acpi_bus_unregister_driver(&xen_acpi_processor_driver);
+
+	/*
+	 * stub reserve space again to prevent any chance of native
+	 * driver loading.
+	 */
+	xen_stub_processor_init();
+	return;
+}
+
+module_init(xen_acpi_processor_init);
+module_exit(xen_acpi_processor_exit);
+ACPI_MODULE_NAME("xen-acpi-cpuhotplug");
+MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
+MODULE_DESCRIPTION("Xen Hotplug CPU Driver");
+MODULE_LICENSE("GPL");
@@ -54,6 +54,9 @@
 int xen_stub_processor_init(void);
 void xen_stub_processor_exit(void);
  
+void xen_pcpu_hotplug_sync(void);
+int xen_pcpu_id(uint32_t acpi_id);
+
 int xen_acpi_notify_hypervisor_state(u8 sleep_state,
 				     u32 pm1a_cnt, u32 pm1b_cnd);
  
@@ -324,6 +324,13 @@
 };
 DEFINE_GUEST_HANDLE_STRUCT(xenpf_cpu_ol);
  
+#define XENPF_cpu_hotadd	58
+struct xenpf_cpu_hotadd {
+	uint32_t apic_id;
+	uint32_t acpi_id;
+	uint32_t pxm;
+};
+
 #define XENPF_mem_hotadd	59
 struct xenpf_mem_hotadd {
 	uint64_t spfn;
@@ -361,6 +368,7 @@
 		struct xenpf_set_processor_pminfo set_pminfo;
 		struct xenpf_pcpuinfo          pcpu_info;
 		struct xenpf_cpu_ol            cpu_ol;
+		struct xenpf_cpu_hotadd        cpu_add;
 		struct xenpf_mem_hotadd        mem_add;
 		struct xenpf_core_parking      core_parking;
 		uint8_t                        pad[128];
...	...	@@ -202,6 +202,18 @@
202	202	to hot-add memory at runtime (the hot-added memory cannot be
203	203	removed until machine stop), select Y/M here, otherwise select N.
204	204
	205	+config XEN_ACPI_HOTPLUG_CPU
	206	+ tristate "Xen ACPI cpu hotplug"
	207	+ depends on XEN_DOM0 && XEN_STUB && ACPI
	208	+ select ACPI_CONTAINER
	209	+ default n
	210	+ help
	211	+ Xen ACPI cpu enumerating and hotplugging
	212	+
	213	+ For hotplugging, currently Xen only support ACPI cpu hotadd.
	214	+ If you want to hotadd cpu at runtime (the hotadded cpu cannot
	215	+ be removed until machine stop), select Y/M here.
	216	+
205	217	config XEN_ACPI_PROCESSOR
206	218	tristate "Xen ACPI processor"
207	219	depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
...	...	@@ -32,6 +32,7 @@
32	32	obj-$(CONFIG_XEN_PRIVCMD) += xen-privcmd.o
33	33	obj-$(CONFIG_XEN_STUB) += xen-stub.o
34	34	obj-$(CONFIG_XEN_ACPI_HOTPLUG_MEMORY) += xen-acpi-memhotplug.o
	35	+obj-$(CONFIG_XEN_ACPI_HOTPLUG_CPU) += xen-acpi-cpuhotplug.o
35	36	obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o
36	37	xen-evtchn-y := evtchn.o
37	38	xen-gntdev-y := gntdev.o
...	...	@@ -333,6 +333,41 @@
333	333	return IRQ_HANDLED;
334	334	}
335	335
	336	+/* Sync with Xen hypervisor after cpu hotadded */
	337	+void xen_pcpu_hotplug_sync(void)
	338	+{
	339	+ schedule_work(&xen_pcpu_work);
	340	+}
	341	+EXPORT_SYMBOL_GPL(xen_pcpu_hotplug_sync);
	342	+
	343	+/*
	344	+ * For hypervisor presented cpu, return logic cpu id;
	345	+ * For hypervisor non-presented cpu, return -ENODEV.
	346	+ */
	347	+int xen_pcpu_id(uint32_t acpi_id)
	348	+{
	349	+ int cpu_id = 0, max_id = 0;
	350	+ struct xen_platform_op op;
	351	+
	352	+ op.cmd = XENPF_get_cpuinfo;
	353	+ while (cpu_id <= max_id) {
	354	+ op.u.pcpu_info.xen_cpuid = cpu_id;
	355	+ if (HYPERVISOR_dom0_op(&op)) {
	356	+ cpu_id++;
	357	+ continue;
	358	+ }
	359	+
	360	+ if (acpi_id == op.u.pcpu_info.acpi_id)
	361	+ return cpu_id;
	362	+ if (op.u.pcpu_info.max_present > max_id)
	363	+ max_id = op.u.pcpu_info.max_present;
	364	+ cpu_id++;
	365	+ }
	366	+
	367	+ return -ENODEV;
	368	+}
	369	+EXPORT_SYMBOL_GPL(xen_pcpu_id);
	370	+
336	371	static int __init xen_pcpu_init(void)
337	372	{
338	373	int irq, ret;
	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/cpu.h>
	23	+#include <linux/acpi.h>
	24	+#include <linux/uaccess.h>
	25	+#include <acpi/acpi_bus.h>
	26	+#include <acpi/acpi_drivers.h>
	27	+#include <acpi/processor.h>
	28	+
	29	+#include <xen/acpi.h>
	30	+#include <xen/interface/platform.h>
	31	+#include <asm/xen/hypercall.h>
	32	+
	33	+#define PREFIX "ACPI:xen_cpu_hotplug:"
	34	+
	35	+#define INSTALL_NOTIFY_HANDLER 0
	36	+#define UNINSTALL_NOTIFY_HANDLER 1
	37	+
	38	+static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr);
	39	+
	40	+/* --------------------------------------------------------------------------
	41	+ Driver Interface
	42	+-------------------------------------------------------------------------- */
	43	+
	44	+static int xen_acpi_processor_enable(struct acpi_device *device)
	45	+{
	46	+ acpi_status status = 0;
	47	+ unsigned long long value;
	48	+ union acpi_object object = { 0 };
	49	+ struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
	50	+ struct acpi_processor *pr;
	51	+
	52	+ pr = acpi_driver_data(device);
	53	+ if (!pr) {
	54	+ pr_err(PREFIX "Cannot find driver data\n");
	55	+ return -EINVAL;
	56	+ }
	57	+
	58	+ if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
	59	+ /* Declared with "Processor" statement; match ProcessorID */
	60	+ status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
	61	+ if (ACPI_FAILURE(status)) {
	62	+ pr_err(PREFIX "Evaluating processor object\n");
	63	+ return -ENODEV;
	64	+ }
	65	+
	66	+ pr->acpi_id = object.processor.proc_id;
	67	+ } else {
	68	+ /* Declared with "Device" statement; match _UID */
	69	+ status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
	70	+ NULL, &value);
	71	+ if (ACPI_FAILURE(status)) {
	72	+ pr_err(PREFIX "Evaluating processor _UID\n");
	73	+ return -ENODEV;
	74	+ }
	75	+
	76	+ pr->acpi_id = value;
	77	+ }
	78	+
	79	+ pr->id = xen_pcpu_id(pr->acpi_id);
	80	+
	81	+ if ((int)pr->id < 0)
	82	+ /* This cpu is not presented at hypervisor, try to hotadd it */
	83	+ if (ACPI_FAILURE(xen_acpi_cpu_hotadd(pr))) {
	84	+ pr_err(PREFIX "Hotadd CPU (acpi_id = %d) failed.\n",
	85	+ pr->acpi_id);
	86	+ return -ENODEV;
	87	+ }
	88	+
	89	+ return 0;
	90	+}
	91	+
	92	+static int __cpuinit xen_acpi_processor_add(struct acpi_device *device)
	93	+{
	94	+ int ret;
	95	+ struct acpi_processor *pr;
	96	+
	97	+ if (!device)
	98	+ return -EINVAL;
	99	+
	100	+ pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
	101	+ if (!pr)
	102	+ return -ENOMEM;
	103	+
	104	+ pr->handle = device->handle;
	105	+ strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
	106	+ strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
	107	+ device->driver_data = pr;
	108	+
	109	+ ret = xen_acpi_processor_enable(device);
	110	+ if (ret)
	111	+ pr_err(PREFIX "Error when enabling Xen processor\n");
	112	+
	113	+ return ret;
	114	+}
	115	+
	116	+static int xen_acpi_processor_remove(struct acpi_device *device, int type)
	117	+{
	118	+ struct acpi_processor *pr;
	119	+
	120	+ if (!device)
	121	+ return -EINVAL;
	122	+
	123	+ pr = acpi_driver_data(device);
	124	+ if (!pr)
	125	+ return -EINVAL;
	126	+
	127	+ kfree(pr);
	128	+ return 0;
	129	+}
	130	+
	131	+/*--------------------------------------------------------------
	132	+ Acpi processor hotplug support
	133	+--------------------------------------------------------------*/
	134	+
	135	+static int is_processor_present(acpi_handle handle)
	136	+{
	137	+ acpi_status status;
	138	+ unsigned long long sta = 0;
	139	+
	140	+
	141	+ status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
	142	+
	143	+ if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
	144	+ return 1;
	145	+
	146	+ /*
	147	+ * _STA is mandatory for a processor that supports hot plug
	148	+ */
	149	+ if (status == AE_NOT_FOUND)
	150	+ pr_info(PREFIX "Processor does not support hot plug\n");
	151	+ else
	152	+ pr_info(PREFIX "Processor Device is not present");
	153	+ return 0;
	154	+}
	155	+
	156	+static int xen_apic_id(acpi_handle handle)
	157	+{
	158	+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	159	+ union acpi_object *obj;
	160	+ struct acpi_madt_local_apic *lapic;
	161	+ int apic_id;
	162	+
	163	+ if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
	164	+ return -EINVAL;
	165	+
	166	+ if (!buffer.length \|\| !buffer.pointer)
	167	+ return -EINVAL;
	168	+
	169	+ obj = buffer.pointer;
	170	+ if (obj->type != ACPI_TYPE_BUFFER \|\|
	171	+ obj->buffer.length < sizeof(*lapic)) {
	172	+ kfree(buffer.pointer);
	173	+ return -EINVAL;
	174	+ }
	175	+
	176	+ lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
	177	+
	178	+ if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC \|\|
	179	+ !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
	180	+ kfree(buffer.pointer);
	181	+ return -EINVAL;
	182	+ }
	183	+
	184	+ apic_id = (uint32_t)lapic->id;
	185	+ kfree(buffer.pointer);
	186	+ buffer.length = ACPI_ALLOCATE_BUFFER;
	187	+ buffer.pointer = NULL;
	188	+
	189	+ return apic_id;
	190	+}
	191	+
	192	+static int xen_hotadd_cpu(struct acpi_processor *pr)
	193	+{
	194	+ int cpu_id, apic_id, pxm;
	195	+ struct xen_platform_op op;
	196	+
	197	+ apic_id = xen_apic_id(pr->handle);
	198	+ if (apic_id < 0) {
	199	+ pr_err(PREFIX "Failed to get apic_id for acpi_id %d\n",
	200	+ pr->acpi_id);
	201	+ return -ENODEV;
	202	+ }
	203	+
	204	+ pxm = xen_acpi_get_pxm(pr->handle);
	205	+ if (pxm < 0) {
	206	+ pr_err(PREFIX "Failed to get _PXM for acpi_id %d\n",
	207	+ pr->acpi_id);
	208	+ return pxm;
	209	+ }
	210	+
	211	+ op.cmd = XENPF_cpu_hotadd;
	212	+ op.u.cpu_add.apic_id = apic_id;
	213	+ op.u.cpu_add.acpi_id = pr->acpi_id;
	214	+ op.u.cpu_add.pxm = pxm;
	215	+
	216	+ cpu_id = HYPERVISOR_dom0_op(&op);
	217	+ if (cpu_id < 0)
	218	+ pr_err(PREFIX "Failed to hotadd CPU for acpi_id %d\n",
	219	+ pr->acpi_id);
	220	+
	221	+ return cpu_id;
	222	+}
	223	+
	224	+static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr)
	225	+{
	226	+ if (!is_processor_present(pr->handle))
	227	+ return AE_ERROR;
	228	+
	229	+ pr->id = xen_hotadd_cpu(pr);
	230	+ if ((int)pr->id < 0)
	231	+ return AE_ERROR;
	232	+
	233	+ /*
	234	+ * Sync with Xen hypervisor, providing new /sys/.../xen_cpuX
	235	+ * interface after cpu hotadded.
	236	+ */
	237	+ xen_pcpu_hotplug_sync();
	238	+
	239	+ return AE_OK;
	240	+}
	241	+
	242	+static
	243	+int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
	244	+{
	245	+ acpi_handle phandle;
	246	+ struct acpi_device *pdev;
	247	+
	248	+ if (acpi_get_parent(handle, &phandle))
	249	+ return -ENODEV;
	250	+
	251	+ if (acpi_bus_get_device(phandle, &pdev))
	252	+ return -ENODEV;
	253	+
	254	+ if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR))
	255	+ return -ENODEV;
	256	+
	257	+ return 0;
	258	+}
	259	+
	260	+static int acpi_processor_device_remove(struct acpi_device *device)
	261	+{
	262	+ pr_debug(PREFIX "Xen does not support CPU hotremove\n");
	263	+
	264	+ return -ENOSYS;
	265	+}
	266	+
	267	+static void acpi_processor_hotplug_notify(acpi_handle handle,
	268	+ u32 event, void *data)
	269	+{
	270	+ struct acpi_processor *pr;
	271	+ struct acpi_device *device = NULL;
	272	+ u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
	273	+ int result;
	274	+
	275	+ switch (event) {
	276	+ case ACPI_NOTIFY_BUS_CHECK:
	277	+ case ACPI_NOTIFY_DEVICE_CHECK:
	278	+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	279	+ "Processor driver received %s event\n",
	280	+ (event == ACPI_NOTIFY_BUS_CHECK) ?
	281	+ "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
	282	+
	283	+ if (!is_processor_present(handle))
	284	+ break;
	285	+
	286	+ if (!acpi_bus_get_device(handle, &device))
	287	+ break;
	288	+
	289	+ result = acpi_processor_device_add(handle, &device);
	290	+ if (result) {
	291	+ pr_err(PREFIX "Unable to add the device\n");
	292	+ break;
	293	+ }
	294	+
	295	+ ost_code = ACPI_OST_SC_SUCCESS;
	296	+ break;
	297	+
	298	+ case ACPI_NOTIFY_EJECT_REQUEST:
	299	+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	300	+ "received ACPI_NOTIFY_EJECT_REQUEST\n"));
	301	+
	302	+ if (acpi_bus_get_device(handle, &device)) {
	303	+ pr_err(PREFIX "Device don't exist, dropping EJECT\n");
	304	+ break;
	305	+ }
	306	+ pr = acpi_driver_data(device);
	307	+ if (!pr) {
	308	+ pr_err(PREFIX "Driver data is NULL, dropping EJECT\n");
	309	+ break;
	310	+ }
	311	+
	312	+ /*
	313	+ * TBD: implement acpi_processor_device_remove if Xen support
	314	+ * CPU hotremove in the future.
	315	+ */
	316	+ acpi_processor_device_remove(device);
	317	+ break;
	318	+
	319	+ default:
	320	+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	321	+ "Unsupported event [0x%x]\n", event));
	322	+
	323	+ /* non-hotplug event; possibly handled by other handler */
	324	+ return;
	325	+ }
	326	+
	327	+ (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
	328	+ return;
	329	+}
	330	+
	331	+static acpi_status is_processor_device(acpi_handle handle)
	332	+{
	333	+ struct acpi_device_info *info;
	334	+ char *hid;
	335	+ acpi_status status;
	336	+
	337	+ status = acpi_get_object_info(handle, &info);
	338	+ if (ACPI_FAILURE(status))
	339	+ return status;
	340	+
	341	+ if (info->type == ACPI_TYPE_PROCESSOR) {
	342	+ kfree(info);
	343	+ return AE_OK; /* found a processor object */
	344	+ }
	345	+
	346	+ if (!(info->valid & ACPI_VALID_HID)) {
	347	+ kfree(info);
	348	+ return AE_ERROR;
	349	+ }
	350	+
	351	+ hid = info->hardware_id.string;
	352	+ if ((hid == NULL) \|\| strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
	353	+ kfree(info);
	354	+ return AE_ERROR;
	355	+ }
	356	+
	357	+ kfree(info);
	358	+ return AE_OK; /* found a processor device object */
	359	+}
	360	+
	361	+static acpi_status
	362	+processor_walk_namespace_cb(acpi_handle handle,
	363	+ u32 lvl, void context, void *rv)
	364	+{
	365	+ acpi_status status;
	366	+ int *action = context;
	367	+
	368	+ status = is_processor_device(handle);
	369	+ if (ACPI_FAILURE(status))
	370	+ return AE_OK; /* not a processor; continue to walk */
	371	+
	372	+ switch (*action) {
	373	+ case INSTALL_NOTIFY_HANDLER:
	374	+ acpi_install_notify_handler(handle,
	375	+ ACPI_SYSTEM_NOTIFY,
	376	+ acpi_processor_hotplug_notify,
	377	+ NULL);
	378	+ break;
	379	+ case UNINSTALL_NOTIFY_HANDLER:
	380	+ acpi_remove_notify_handler(handle,
	381	+ ACPI_SYSTEM_NOTIFY,
	382	+ acpi_processor_hotplug_notify);
	383	+ break;
	384	+ default:
	385	+ break;
	386	+ }
	387	+
	388	+ /* found a processor; skip walking underneath */
	389	+ return AE_CTRL_DEPTH;
	390	+}
	391	+
	392	+static
	393	+void acpi_processor_install_hotplug_notify(void)
	394	+{
	395	+ int action = INSTALL_NOTIFY_HANDLER;
	396	+ acpi_walk_namespace(ACPI_TYPE_ANY,
	397	+ ACPI_ROOT_OBJECT,
	398	+ ACPI_UINT32_MAX,
	399	+ processor_walk_namespace_cb, NULL, &action, NULL);
	400	+}
	401	+
	402	+static
	403	+void acpi_processor_uninstall_hotplug_notify(void)
	404	+{
	405	+ int action = UNINSTALL_NOTIFY_HANDLER;
	406	+ acpi_walk_namespace(ACPI_TYPE_ANY,
	407	+ ACPI_ROOT_OBJECT,
	408	+ ACPI_UINT32_MAX,
	409	+ processor_walk_namespace_cb, NULL, &action, NULL);
	410	+}
	411	+
	412	+static const struct acpi_device_id processor_device_ids[] = {
	413	+ {ACPI_PROCESSOR_OBJECT_HID, 0},
	414	+ {ACPI_PROCESSOR_DEVICE_HID, 0},
	415	+ {"", 0},
	416	+};
	417	+MODULE_DEVICE_TABLE(acpi, processor_device_ids);
	418	+
	419	+static struct acpi_driver xen_acpi_processor_driver = {
	420	+ .name = "processor",
	421	+ .class = ACPI_PROCESSOR_CLASS,
	422	+ .ids = processor_device_ids,
	423	+ .ops = {
	424	+ .add = xen_acpi_processor_add,
	425	+ .remove = xen_acpi_processor_remove,
	426	+ },
	427	+};
	428	+
	429	+static int __init xen_acpi_processor_init(void)
	430	+{
	431	+ int result = 0;
	432	+
	433	+ if (!xen_initial_domain())
	434	+ return -ENODEV;
	435	+
	436	+ /* unregister the stub which only used to reserve driver space */
	437	+ xen_stub_processor_exit();
	438	+
	439	+ result = acpi_bus_register_driver(&xen_acpi_processor_driver);
	440	+ if (result < 0) {
	441	+ xen_stub_processor_init();
	442	+ return result;
	443	+ }
	444	+
	445	+ acpi_processor_install_hotplug_notify();
	446	+ return 0;
	447	+}
	448	+
	449	+static void __exit xen_acpi_processor_exit(void)
	450	+{
	451	+ if (!xen_initial_domain())
	452	+ return;
	453	+
	454	+ acpi_processor_uninstall_hotplug_notify();
	455	+
	456	+ acpi_bus_unregister_driver(&xen_acpi_processor_driver);
	457	+
	458	+ /*
	459	+ * stub reserve space again to prevent any chance of native
	460	+ * driver loading.
	461	+ */
	462	+ xen_stub_processor_init();
	463	+ return;
	464	+}
	465	+
	466	+module_init(xen_acpi_processor_init);
	467	+module_exit(xen_acpi_processor_exit);
	468	+ACPI_MODULE_NAME("xen-acpi-cpuhotplug");
	469	+MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
	470	+MODULE_DESCRIPTION("Xen Hotplug CPU Driver");
	471	+MODULE_LICENSE("GPL");
...	...	@@ -54,6 +54,9 @@
54	54	int xen_stub_processor_init(void);
55	55	void xen_stub_processor_exit(void);
56	56
	57	+void xen_pcpu_hotplug_sync(void);
	58	+int xen_pcpu_id(uint32_t acpi_id);
	59	+
57	60	int xen_acpi_notify_hypervisor_state(u8 sleep_state,
58	61	u32 pm1a_cnt, u32 pm1b_cnd);
59	62
...	...	@@ -324,6 +324,13 @@
324	324	};
325	325	DEFINE_GUEST_HANDLE_STRUCT(xenpf_cpu_ol);
326	326
	327	+#define XENPF_cpu_hotadd 58
	328	+struct xenpf_cpu_hotadd {
	329	+ uint32_t apic_id;
	330	+ uint32_t acpi_id;
	331	+ uint32_t pxm;
	332	+};
	333	+
327	334	#define XENPF_mem_hotadd 59
328	335	struct xenpf_mem_hotadd {
329	336	uint64_t spfn;
...	...	@@ -361,6 +368,7 @@
361	368	struct xenpf_set_processor_pminfo set_pminfo;
362	369	struct xenpf_pcpuinfo pcpu_info;
363	370	struct xenpf_cpu_ol cpu_ol;
	371	+ struct xenpf_cpu_hotadd cpu_add;
364	372	struct xenpf_mem_hotadd mem_add;
365	373	struct xenpf_core_parking core_parking;
366	374	uint8_t pad[128];