diff options
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/Makefile | 1 | ||||
| -rw-r--r-- | drivers/xen/pcpu.c | 371 |
2 files changed, 372 insertions, 0 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index a787029..d80bea5 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o obj-$(CONFIG_XEN_PVHVM) += platform-pci.o obj-$(CONFIG_XEN_TMEM) += tmem.o obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o +obj-$(CONFIG_XEN_DOM0) += pcpu.o obj-$(CONFIG_XEN_DOM0) += pci.o acpi.o obj-$(CONFIG_XEN_MCE_LOG) += mcelog.o obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/ diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c new file mode 100644 index 0000000..067fcfa --- /dev/null +++ b/drivers/xen/pcpu.c @@ -0,0 +1,371 @@ +/****************************************************************************** + * pcpu.c + * Management physical cpu in dom0, get pcpu info and provide sys interface + * + * 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 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 <linux/capability.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> + +#define XEN_PCPU "xen_cpu: " + +/* + * @cpu_id: Xen physical cpu logic number + * @flags: Xen physical cpu status flag + * - XEN_PCPU_FLAGS_ONLINE: cpu is online + * - XEN_PCPU_FLAGS_INVALID: cpu is not present + */ +struct pcpu { + struct list_head list; + struct device dev; + uint32_t cpu_id; + uint32_t flags; +}; + +static struct bus_type xen_pcpu_subsys = { + .name = "xen_cpu", + .dev_name = "xen_cpu", +}; + +static DEFINE_MUTEX(xen_pcpu_lock); + +static LIST_HEAD(xen_pcpus); + +static int xen_pcpu_down(uint32_t cpu_id) +{ + struct xen_platform_op op = { + .cmd = XENPF_cpu_offline, + .interface_version = XENPF_INTERFACE_VERSION, + .u.cpu_ol.cpuid = cpu_id, + }; + + return HYPERVISOR_dom0_op(&op); +} + +static int xen_pcpu_up(uint32_t cpu_id) +{ + struct xen_platform_op op = { + .cmd = XENPF_cpu_online, + .interface_version = XENPF_INTERFACE_VERSION, + .u.cpu_ol.cpuid = cpu_id, + }; + + return HYPERVISOR_dom0_op(&op); +} + +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 *pcpu = container_of(dev, struct pcpu, dev); + unsigned long long val; + ssize_t ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (kstrtoull(buf, 0, &val) < 0) + return -EINVAL; + + switch (val) { + case 0: + ret = xen_pcpu_down(pcpu->cpu_id); + break; + case 1: + ret = xen_pcpu_up(pcpu->cpu_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 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 cpu_id) +{ + struct pcpu *pcpu; + + list_for_each_entry(pcpu, &xen_pcpus, list) { + if (pcpu->cpu_id == cpu_id) + return pcpu; + } + + return NULL; +} + +static void pcpu_release(struct device *dev) +{ + struct pcpu *pcpu = container_of(dev, struct pcpu, dev); + + list_del(&pcpu->list); + kfree(pcpu); +} + +static void unregister_and_remove_pcpu(struct pcpu *pcpu) +{ + struct device *dev; + + if (!pcpu) + return; + + dev = &pcpu->dev; + if (dev->id) + device_remove_file(dev, &dev_attr_online); + + /* pcpu remove would be implicitly done */ + device_unregister(dev); +} + +static int register_pcpu(struct pcpu *pcpu) +{ + struct device *dev; + int err = -EINVAL; + + if (!pcpu) + return err; + + dev = &pcpu->dev; + dev->bus = &xen_pcpu_subsys; + dev->id = pcpu->cpu_id; + dev->release = pcpu_release; + + err = device_register(dev); + if (err) { + pcpu_release(dev); + return err; + } + + /* + * Xen never offline cpu0 due to several restrictions + * and assumptions. This basically doesn't add a sys control + * to user, one cannot attempt to offline BSP. + */ + if (dev->id) { + err = device_create_file(dev, &dev_attr_online); + if (err) { + device_unregister(dev); + return err; + } + } + + return 0; +} + +static struct pcpu *create_and_register_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->list); + pcpu->cpu_id = info->xen_cpuid; + pcpu->flags = info->flags; + + /* Need hold on xen_pcpu_lock before pcpu list manipulations */ + list_add_tail(&pcpu->list, &xen_pcpus); + + err = register_pcpu(pcpu); + if (err) { + pr_warning(XEN_PCPU "Failed to register pcpu%u\n", + info->xen_cpuid); + return ERR_PTR(-ENOENT); + } + + return pcpu; +} + +/* + * Caller should hold the xen_pcpu_lock + */ +static int sync_pcpu(uint32_t cpu, uint32_t *max_cpu) +{ + 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, + }; + + ret = HYPERVISOR_dom0_op(&op); + if (ret) + return ret; + + info = &op.u.pcpu_info; + if (max_cpu) + *max_cpu = info->max_present; + + pcpu = get_pcpu(cpu); + + /* + * Only those at cpu present map has its sys interface. + */ + if (info->flags & XEN_PCPU_FLAGS_INVALID) { + if (pcpu) + unregister_and_remove_pcpu(pcpu); + return 0; + } + + if (!pcpu) { + pcpu = create_and_register_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 = 0, max_cpu = 0; + int err = 0; + struct pcpu *pcpu, *tmp; + + mutex_lock(&xen_pcpu_lock); + + while (!err && (cpu <= max_cpu)) { + err = sync_pcpu(cpu, &max_cpu); + cpu++; + } + + if (err) + list_for_each_entry_safe(pcpu, tmp, &xen_pcpus, list) + unregister_and_remove_pcpu(pcpu); + + mutex_unlock(&xen_pcpu_lock); + + return err; +} + +static void xen_pcpu_work_fn(struct work_struct *work) +{ + xen_sync_pcpus(); +} +static DECLARE_WORK(xen_pcpu_work, xen_pcpu_work_fn); + +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 irq, ret; + + if (!xen_initial_domain()) + return -ENODEV; + + irq = bind_virq_to_irqhandler(VIRQ_PCPU_STATE, 0, + xen_pcpu_interrupt, 0, + "xen-pcpu", NULL); + if (irq < 0) { + pr_warning(XEN_PCPU "Failed to bind pcpu virq\n"); + return irq; + } + + ret = subsys_system_register(&xen_pcpu_subsys, NULL); + if (ret) { + pr_warning(XEN_PCPU "Failed to register pcpu subsys\n"); + goto err1; + } + + ret = xen_sync_pcpus(); + if (ret) { + pr_warning(XEN_PCPU "Failed to sync pcpu info\n"); + goto err2; + } + + return 0; + +err2: + bus_unregister(&xen_pcpu_subsys); +err1: + unbind_from_irqhandler(irq, NULL); + return ret; +} +arch_initcall(xen_pcpu_init); |
