xen/acpi: ACPI cpu hotplug
authorLiu Jinsong <jinsong.liu@intel.com>
Fri, 25 Jan 2013 07:43:34 +0000 (15:43 +0800)
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Wed, 20 Feb 2013 03:02:29 +0000 (22:02 -0500)
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>
drivers/xen/Kconfig
drivers/xen/Makefile
drivers/xen/pcpu.c
drivers/xen/xen-acpi-cpuhotplug.c [new file with mode: 0644]
include/xen/acpi.h
include/xen/interface/platform.h

index dcffad1b47ca168b7dd269e543d4067e373cd87a..5a32232cf7c15cdc05536ecb157eeb86048154e0 100644 (file)
@@ -202,6 +202,18 @@ config XEN_ACPI_HOTPLUG_MEMORY
          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
index 1605f594ff5678b8eee6d6b603bd6c3ee6bc3d3a..eabd0ee1c2bc2f298d0938515e204b42430e9852 100644 (file)
@@ -32,6 +32,7 @@ obj-$(CONFIG_XEN_PCIDEV_BACKEND)      += xen-pciback/
 obj-$(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
index 067fcfa1723e0b846b9522038edb5ef1dc96f4e0..0836a18675b19c38031c7da97effad4188eb6624 100644 (file)
@@ -333,6 +333,41 @@ static irqreturn_t xen_pcpu_interrupt(int irq, void *dev_id)
        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;
diff --git a/drivers/xen/xen-acpi-cpuhotplug.c b/drivers/xen/xen-acpi-cpuhotplug.c
new file mode 100644 (file)
index 0000000..9eefbb0
--- /dev/null
@@ -0,0 +1,471 @@
+/*
+ * 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");
index dc69c91605b81979ffe9f49fb770da689c8900e2..c962d5f5b38b36fd0f33aa21f69b1abf286d03e0 100644 (file)
@@ -54,6 +54,9 @@ void xen_stub_memory_device_exit(void);
 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);
 
index 2c4fb4bb07df4442c82a99ddbb26a6ec5b4fd33d..c57d5f67f702e3160aba466702e3a720412f09ed 100644 (file)
@@ -324,6 +324,13 @@ struct xenpf_cpu_ol {
 };
 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 xen_platform_op {
                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];