Message-ID: <DE8DF0795D48FD4CA783C40EC8292335154F3E@SHSMSX101.ccr.corp.intel.com>
Date:	Thu, 19 Apr 2012 13:33:03 +0000
From:	"Liu, Jinsong" <jinsong.liu@...el.com>
To:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	"xen-devel@...ts.xensource.com" <xen-devel@...ts.xensource.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH 3/3] Xen physical cpus interface

>From afdd30a7769e706e9be64f80d64136e2e267ecb9 Mon Sep 17 00:00:00 2001
From: Liu, Jinsong <jinsong.liu@...el.com>
Date: Fri, 20 Apr 2012 05:11:58 +0800
Subject: [PATCH 3/3] Xen physical cpus interface

Manage physical cpus in dom0, get physical cpus info and provide sys interface.

Signed-off-by: Liu, Jinsong <jinsong.liu@...el.com>
Signed-off-by: Jiang, Yunhong <yunhong.jiang@...el.com>
---
 drivers/xen/Makefile             |    1 +
 drivers/xen/pcpu.c               |  393 ++++++++++++++++++++++++++++++++++++++
 include/xen/interface/platform.h |   10 +-
 include/xen/interface/xen.h      |    1 +
 4 files changed, 404 insertions(+), 1 deletions(-)
 create mode 100644 drivers/xen/pcpu.c

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 1d3e763..d12d14d 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_XEN_PVHVM)			+= platform-pci.o
 obj-$(CONFIG_XEN_TMEM)			+= tmem.o
 obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
 obj-$(CONFIG_XEN_DOM0)			+= pci.o
+obj-$(CONFIG_XEN_DOM0)			+= pcpu.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/
 obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
 obj-$(CONFIG_XEN_ACPI_PROCESSOR)	+= xen-acpi-processor.o
diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c
new file mode 100644
index 0000000..9295def
--- /dev/null
+++ b/drivers/xen/pcpu.c
@@ -0,0 +1,393 @@
+/******************************************************************************
+ * pcpu.c
+ * Management physical cpu in dom0, get pcpu info and provide sys interface
+ *
+ * Copyright (c) 2012 Intel Corporation
+ * Author: Liu, Jinsong <jinsong.liu@...el.com>
+ * Author: Jiang, Yunhong <yunhong.jiang@...el.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/cpu.h>
+#include <linux/stat.h>
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+#include <xen/events.h>
+#include <xen/interface/platform.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+struct pcpu {
+	struct list_head pcpu_list;
+	struct device dev;
+	uint32_t xen_id;
+	uint32_t apic_id;
+	uint32_t acpi_id;
+	uint32_t flags;
+};
+
+static struct bus_type xen_pcpu_subsys = {
+	.name = "xen_cpu",
+	.dev_name = "xen_cpu",
+};
+
+static DEFINE_MUTEX(xen_pcpu_lock);
+#define get_pcpu_lock() mutex_lock(&xen_pcpu_lock);
+#define put_pcpu_lock() mutex_unlock(&xen_pcpu_lock);
+
+#define XEN_PCPU "xen_cpu: "
+
+struct xen_pcpus {
+	struct list_head list;
+};
+static struct xen_pcpus xen_pcpus;
+
+static int xen_pcpu_down(uint32_t xen_id)
+{
+	int ret;
+	struct xen_platform_op op = {
+		.cmd			= XENPF_cpu_offline,
+		.interface_version	= XENPF_INTERFACE_VERSION,
+		.u.cpu_ol.cpuid		= xen_id,
+	};
+
+	ret = HYPERVISOR_dom0_op(&op);
+	return ret;
+}
+
+static int xen_pcpu_up(uint32_t xen_id)
+{
+	int ret;
+	struct xen_platform_op op = {
+		.cmd			= XENPF_cpu_online,
+		.interface_version	= XENPF_INTERFACE_VERSION,
+		.u.cpu_ol.cpuid		= xen_id,
+	};
+
+	ret = HYPERVISOR_dom0_op(&op);
+	return ret;
+}
+
+static ssize_t show_online(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct pcpu *cpu = container_of(dev, struct pcpu, dev);
+
+	return sprintf(buf, "%u\n", !!(cpu->flags & XEN_PCPU_FLAGS_ONLINE));
+}
+
+static ssize_t __ref store_online(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct pcpu *cpu = container_of(dev, struct pcpu, dev);
+	ssize_t ret;
+
+	switch (buf[0]) {
+	case '0':
+		ret = xen_pcpu_down(cpu->xen_id);
+		break;
+	case '1':
+		ret = xen_pcpu_up(cpu->xen_id);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret >= 0)
+		ret = count;
+	return ret;
+}
+static DEVICE_ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online);
+
+static ssize_t show_apicid(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct pcpu *cpu = container_of(dev, struct pcpu, dev);
+
+	return sprintf(buf, "%u\n", cpu->apic_id);
+}
+
+static ssize_t show_acpiid(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct pcpu *cpu = container_of(dev, struct pcpu, dev);
+
+	return sprintf(buf, "%u\n", cpu->acpi_id);
+}
+static DEVICE_ATTR(apic_id, S_IRUGO, show_apicid, NULL);
+static DEVICE_ATTR(acpi_id, S_IRUGO, show_acpiid, NULL);
+
+static bool xen_pcpu_online(uint32_t flags)
+{
+	return !!(flags & XEN_PCPU_FLAGS_ONLINE);
+}
+
+static void pcpu_online_status(struct xenpf_pcpuinfo *info,
+			       struct pcpu *pcpu)
+{
+	if (xen_pcpu_online(info->flags) &&
+	   !xen_pcpu_online(pcpu->flags)) {
+		/* the pcpu is onlined */
+		pcpu->flags |= XEN_PCPU_FLAGS_ONLINE;
+		kobject_uevent(&pcpu->dev.kobj, KOBJ_ONLINE);
+	} else if (!xen_pcpu_online(info->flags) &&
+		    xen_pcpu_online(pcpu->flags)) {
+		/* The pcpu is offlined */
+		pcpu->flags &= ~XEN_PCPU_FLAGS_ONLINE;
+		kobject_uevent(&pcpu->dev.kobj, KOBJ_OFFLINE);
+	}
+}
+
+static struct pcpu *get_pcpu(uint32_t xen_id)
+{
+	struct pcpu *pcpu = NULL;
+
+	list_for_each_entry(pcpu, &xen_pcpus.list, pcpu_list) {
+		if (pcpu->xen_id == xen_id)
+			return pcpu;
+	}
+	return NULL;
+}
+
+static void pcpu_sys_remove(struct pcpu *pcpu)
+{
+	struct device *dev;
+
+	if (!pcpu)
+		return;
+
+	dev = &pcpu->dev;
+	if (dev->id)
+		device_remove_file(dev, &dev_attr_online);
+	device_remove_file(dev, &dev_attr_acpi_id);
+	device_remove_file(dev, &dev_attr_apic_id);
+	device_unregister(dev);
+}
+
+static void free_pcpu(struct pcpu *pcpu)
+{
+	if (!pcpu)
+		return;
+
+	pcpu_sys_remove(pcpu);
+	list_del(&pcpu->pcpu_list);
+	kfree(pcpu);
+}
+
+static int pcpu_sys_create(struct pcpu *pcpu)
+{
+	struct device *dev;
+	int err = -EINVAL;
+
+	if (!pcpu)
+		return err;
+
+	dev = &pcpu->dev;
+	dev->bus = &xen_pcpu_subsys;
+	dev->id = pcpu->xen_id;
+
+	err = device_register(dev);
+	if (err)
+		goto err1;
+
+	err = device_create_file(dev, &dev_attr_apic_id);
+	if (err)
+		goto err2;
+	err = device_create_file(dev, &dev_attr_acpi_id);
+	if (err)
+		goto err3;
+	/* Not open pcpu0 online access to user */
+	if (dev->id) {
+		err = device_create_file(dev, &dev_attr_online);
+		if (err)
+			goto err4;
+	}
+
+	return 0;
+
+err4:
+	device_remove_file(dev, &dev_attr_acpi_id);
+err3:
+	device_remove_file(dev, &dev_attr_apic_id);
+err2:
+	device_unregister(dev);
+err1:
+	return err;
+}
+
+static struct pcpu *init_pcpu(struct xenpf_pcpuinfo *info)
+{
+	struct pcpu *pcpu;
+	int err;
+
+	if (info->flags & XEN_PCPU_FLAGS_INVALID)
+		return ERR_PTR(-ENODEV);
+
+	pcpu = kzalloc(sizeof(struct pcpu), GFP_KERNEL);
+	if (!pcpu)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&pcpu->pcpu_list);
+	pcpu->xen_id = info->xen_cpuid;
+	pcpu->apic_id = info->apic_id;
+	pcpu->acpi_id = info->acpi_id;
+	pcpu->flags = info->flags;
+
+	err = pcpu_sys_create(pcpu);
+	if (err) {
+		pr_warning(XEN_PCPU "Failed to register pcpu%d\n",
+			   info->xen_cpuid);
+		kfree(pcpu);
+		return ERR_PTR(-ENOENT);
+	}
+
+	list_add_tail(&pcpu->pcpu_list, &xen_pcpus.list);
+	return pcpu;
+}
+
+/*
+ * Caller should hold the pcpu lock
+ */
+static int _sync_pcpu(uint32_t cpu_num, uint32_t *ptr_max_cpu_num)
+{
+	int ret;
+	struct pcpu *pcpu = NULL;
+	struct xenpf_pcpuinfo *info;
+	struct xen_platform_op op = {
+		.cmd                   = XENPF_get_cpuinfo,
+		.interface_version     = XENPF_INTERFACE_VERSION,
+		.u.pcpu_info.xen_cpuid = cpu_num,
+	};
+
+	ret = HYPERVISOR_dom0_op(&op);
+	if (ret)
+		return ret;
+
+	info = &op.u.pcpu_info;
+	if (ptr_max_cpu_num)
+		*ptr_max_cpu_num = info->max_present;
+
+	pcpu = get_pcpu(cpu_num);
+
+	if (info->flags & XEN_PCPU_FLAGS_INVALID) {
+		/* The pcpu has been removed */
+		if (pcpu)
+			free_pcpu(pcpu);
+		return 0;
+	}
+
+	if (!pcpu) {
+		pcpu = init_pcpu(info);
+		if (IS_ERR_OR_NULL(pcpu))
+			return -ENODEV;
+	} else
+		pcpu_online_status(info, pcpu);
+
+	return 0;
+}
+
+/*
+ * Sync dom0's pcpu information with xen hypervisor's
+ */
+static int xen_sync_pcpus(void)
+{
+	/*
+	 * Boot cpu always have cpu_id 0 in xen
+	 */
+	uint32_t cpu_num = 0, max_cpu_num = 0;
+	int err = 0;
+	struct list_head *elem, *tmp;
+	struct pcpu *pcpu;
+
+	get_pcpu_lock();
+
+	while (!err && (cpu_num <= max_cpu_num)) {
+		err = _sync_pcpu(cpu_num, &max_cpu_num);
+		cpu_num++;
+	}
+
+	if (err) {
+		list_for_each_safe(elem, tmp, &xen_pcpus.list) {
+			pcpu = list_entry(elem, struct pcpu, pcpu_list);
+			free_pcpu(pcpu);
+		}
+	}
+
+	put_pcpu_lock();
+
+	return err;
+}
+
+static void xen_pcpu_dpc(struct work_struct *work)
+{
+	xen_sync_pcpus();
+}
+static DECLARE_WORK(xen_pcpu_work, xen_pcpu_dpc);
+
+static irqreturn_t xen_pcpu_interrupt(int irq, void *dev_id)
+{
+	schedule_work(&xen_pcpu_work);
+	return IRQ_HANDLED;
+}
+
+static int __init xen_pcpu_init(void)
+{
+	int ret;
+
+	if (!xen_initial_domain())
+		return -ENODEV;
+
+	ret = subsys_system_register(&xen_pcpu_subsys, NULL);
+	if (ret) {
+		pr_warning(XEN_PCPU "Failed to register pcpu subsys\n");
+		return ret;
+	}
+
+	INIT_LIST_HEAD(&xen_pcpus.list);
+
+	ret = xen_sync_pcpus();
+	if (ret) {
+		pr_warning(XEN_PCPU "Failed to sync pcpu info\n");
+		return ret;
+	}
+
+	ret = bind_virq_to_irqhandler(VIRQ_PCPU_STATE, 0,
+				      xen_pcpu_interrupt, 0,
+				      "pcpu", NULL);
+	if (ret < 0) {
+		pr_warning(XEN_PCPU "Failed to bind pcpu virq\n");
+		return ret;
+	}
+
+	return 0;
+}
+arch_initcall(xen_pcpu_init);
diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h
index 486653f..2c56d4f 100644
--- a/include/xen/interface/platform.h
+++ b/include/xen/interface/platform.h
@@ -298,7 +298,7 @@ struct xenpf_set_processor_pminfo {
 };
 DEFINE_GUEST_HANDLE_STRUCT(xenpf_set_processor_pminfo);
 
-#define XENPF_get_cpuinfo 55
+#define XENPF_get_cpuinfo	55
 struct xenpf_pcpuinfo {
 	/* IN */
 	uint32_t xen_cpuid;
@@ -314,6 +314,13 @@ struct xenpf_pcpuinfo {
 };
 DEFINE_GUEST_HANDLE_STRUCT(xenpf_pcpuinfo);
 
+#define XENPF_cpu_online	56
+#define XENPF_cpu_offline	57
+struct xenpf_cpu_ol {
+	uint32_t cpuid;
+};
+DEFINE_GUEST_HANDLE_STRUCT(xenpf_cpu_ol);
+
 struct xen_platform_op {
 	uint32_t cmd;
 	uint32_t interface_version; /* XENPF_INTERFACE_VERSION */
@@ -330,6 +337,7 @@ struct xen_platform_op {
 		struct xenpf_getidletime       getidletime;
 		struct xenpf_set_processor_pminfo set_pminfo;
 		struct xenpf_pcpuinfo          pcpu_info;
+		struct xenpf_cpu_ol            cpu_ol;
 		uint8_t                        pad[128];
 	} u;
 };
diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index a890804..0801468 100644
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -80,6 +80,7 @@
 #define VIRQ_CONSOLE    2  /* (DOM0) Bytes received on emergency console. */
 #define VIRQ_DOM_EXC    3  /* (DOM0) Exceptional event for some domain.   */
 #define VIRQ_DEBUGGER   6  /* (DOM0) A domain has paused for debugging.   */
+#define VIRQ_PCPU_STATE 9  /* (DOM0) PCPU state changed                   */
 
 /* Architecture-specific VIRQ definitions. */
 #define VIRQ_ARCH_0    16
-- 
1.7.1

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