implement xen pv_irq_ops to paravirtualize irq handling with xen event channel. Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx> Signed-off-by: Akio Takebe <takebe_akio@xxxxxxxxxxxxxx> Signed-off-by: Alex Williamson <alex.williamson@xxxxxx> Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> --- arch/ia64/xen/Makefile | 2 +- arch/ia64/xen/irq_xen.c | 435 ++++++++++++++++++++++++++++++++++++++++++++ arch/ia64/xen/irq_xen.h | 34 ++++ arch/ia64/xen/xen_pv_ops.c | 3 + 4 files changed, 473 insertions(+), 1 deletions(-) create mode 100644 arch/ia64/xen/irq_xen.c create mode 100644 arch/ia64/xen/irq_xen.h diff --git a/arch/ia64/xen/Makefile b/arch/ia64/xen/Makefile index 9b77e8a..01c4289 100644 --- a/arch/ia64/xen/Makefile +++ b/arch/ia64/xen/Makefile @@ -2,7 +2,7 @@ # Makefile for Xen components # -obj-y := hypercall.o xenivt.o xensetup.o xen_pv_ops.o \ +obj-y := hypercall.o xenivt.o xensetup.o xen_pv_ops.o irq_xen.o \ hypervisor.o xencomm.o xcom_hcall.o grant-table.o AFLAGS_xenivt.o += -D__IA64_ASM_PARAVIRTUALIZED_XEN diff --git a/arch/ia64/xen/irq_xen.c b/arch/ia64/xen/irq_xen.c new file mode 100644 index 0000000..af93aad --- /dev/null +++ b/arch/ia64/xen/irq_xen.c @@ -0,0 +1,435 @@ +/****************************************************************************** + * arch/ia64/xen/irq_xen.c + * + * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp> + * VA Linux Systems Japan K.K. + * + * 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. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/cpu.h> + +#include <xen/interface/xen.h> +#include <xen/interface/callback.h> +#include <xen/events.h> + +#include <asm/xen/privop.h> + +#include "irq_xen.h" + +/*************************************************************************** + * pv_irq_ops + * irq operations + */ + +static int +xen_assign_irq_vector(int irq) +{ + struct physdev_irq irq_op; + + irq_op.irq = irq; + if (HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) + return -ENOSPC; + + return irq_op.vector; +} + +static void +xen_free_irq_vector(int vector) +{ + struct physdev_irq irq_op; + + if (vector < IA64_FIRST_DEVICE_VECTOR || + vector > IA64_LAST_DEVICE_VECTOR) + return; + + irq_op.vector = vector; + if (HYPERVISOR_physdev_op(PHYSDEVOP_free_irq_vector, &irq_op)) + printk(KERN_WARNING "%s: xen_free_irq_vecotr fail vector=%d\n", + __func__, vector); +} + + +static DEFINE_PER_CPU(int, timer_irq) = -1; +static DEFINE_PER_CPU(int, ipi_irq) = -1; +static DEFINE_PER_CPU(int, resched_irq) = -1; +static DEFINE_PER_CPU(int, cmc_irq) = -1; +static DEFINE_PER_CPU(int, cmcp_irq) = -1; +static DEFINE_PER_CPU(int, cpep_irq) = -1; +#define NAME_SIZE 15 +static DEFINE_PER_CPU(char[NAME_SIZE], timer_name); +static DEFINE_PER_CPU(char[NAME_SIZE], ipi_name); +static DEFINE_PER_CPU(char[NAME_SIZE], resched_name); +static DEFINE_PER_CPU(char[NAME_SIZE], cmc_name); +static DEFINE_PER_CPU(char[NAME_SIZE], cmcp_name); +static DEFINE_PER_CPU(char[NAME_SIZE], cpep_name); +#undef NAME_SIZE + +struct saved_irq { + unsigned int irq; + struct irqaction *action; +}; +/* 16 should be far optimistic value, since only several percpu irqs + * are registered early. + */ +#define MAX_LATE_IRQ 16 +static struct saved_irq saved_percpu_irqs[MAX_LATE_IRQ]; +static unsigned short late_irq_cnt; +static unsigned short saved_irq_cnt; +static int xen_slab_ready; + +#ifdef CONFIG_SMP +/* Dummy stub. Though we may check XEN_RESCHEDULE_VECTOR before __do_IRQ, + * it ends up to issue several memory accesses upon percpu data and + * thus adds unnecessary traffic to other paths. + */ +static irqreturn_t +xen_dummy_handler(int irq, void *dev_id) +{ + + return IRQ_HANDLED; +} + +static struct irqaction xen_ipi_irqaction = { + .handler = handle_IPI, + .flags = IRQF_DISABLED, + .name = "IPI" +}; + +static struct irqaction xen_resched_irqaction = { + .handler = xen_dummy_handler, + .flags = IRQF_DISABLED, + .name = "resched" +}; + +static struct irqaction xen_tlb_irqaction = { + .handler = xen_dummy_handler, + .flags = IRQF_DISABLED, + .name = "tlb_flush" +}; +#endif + +/* + * This is xen version percpu irq registration, which needs bind + * to xen specific evtchn sub-system. One trick here is that xen + * evtchn binding interface depends on kmalloc because related + * port needs to be freed at device/cpu down. So we cache the + * registration on BSP before slab is ready and then deal them + * at later point. For rest instances happening after slab ready, + * we hook them to xen evtchn immediately. + * + * FIXME: MCA is not supported by far, and thus "nomca" boot param is + * required. + */ +static void +__xen_register_percpu_irq(unsigned int cpu, unsigned int vec, + struct irqaction *action, int save) +{ + irq_desc_t *desc; + int irq = 0; + + if (xen_slab_ready) { + switch (vec) { + case IA64_TIMER_VECTOR: + snprintf(per_cpu(timer_name, cpu), + sizeof(per_cpu(timer_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_virq_to_irqhandler(VIRQ_ITC, cpu, + action->handler, action->flags, + per_cpu(timer_name, cpu), action->dev_id); + per_cpu(timer_irq, cpu) = irq; + break; + case IA64_IPI_RESCHEDULE: + snprintf(per_cpu(resched_name, cpu), + sizeof(per_cpu(resched_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, cpu, + action->handler, action->flags, + per_cpu(resched_name, cpu), action->dev_id); + per_cpu(resched_irq, cpu) = irq; + break; + case IA64_IPI_VECTOR: + snprintf(per_cpu(ipi_name, cpu), + sizeof(per_cpu(ipi_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_ipi_to_irqhandler(XEN_IPI_VECTOR, cpu, + action->handler, action->flags, + per_cpu(ipi_name, cpu), action->dev_id); + per_cpu(ipi_irq, cpu) = irq; + break; + case IA64_CMC_VECTOR: + snprintf(per_cpu(cmc_name, cpu), + sizeof(per_cpu(cmc_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_virq_to_irqhandler(VIRQ_MCA_CMC, cpu, + action->handler, + action->flags, + per_cpu(cmc_name, cpu), + action->dev_id); + per_cpu(cmc_irq, cpu) = irq; + break; + case IA64_CMCP_VECTOR: + snprintf(per_cpu(cmcp_name, cpu), + sizeof(per_cpu(cmcp_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_ipi_to_irqhandler(XEN_CMCP_VECTOR, cpu, + action->handler, + action->flags, + per_cpu(cmcp_name, cpu), + action->dev_id); + per_cpu(cmcp_irq, cpu) = irq; + break; + case IA64_CPEP_VECTOR: + snprintf(per_cpu(cpep_name, cpu), + sizeof(per_cpu(cpep_name, cpu)), + "%s%d", action->name, cpu); + irq = bind_ipi_to_irqhandler(XEN_CPEP_VECTOR, cpu, + action->handler, + action->flags, + per_cpu(cpep_name, cpu), + action->dev_id); + per_cpu(cpep_irq, cpu) = irq; + break; + case IA64_CPE_VECTOR: + case IA64_MCA_RENDEZ_VECTOR: + case IA64_PERFMON_VECTOR: + case IA64_MCA_WAKEUP_VECTOR: + case IA64_SPURIOUS_INT_VECTOR: + /* No need to complain, these aren't supported. */ + break; + default: + printk(KERN_WARNING "Percpu irq %d is unsupported " + "by xen!\n", vec); + break; + } + BUG_ON(irq < 0); + + if (irq > 0) { + /* + * Mark percpu. Without this, migrate_irqs() will + * mark the interrupt for migrations and trigger it + * on cpu hotplug. + */ + desc = irq_desc + irq; + desc->status |= IRQ_PER_CPU; + } + } + + /* For BSP, we cache registered percpu irqs, and then re-walk + * them when initializing APs + */ + if (!cpu && save) { + BUG_ON(saved_irq_cnt == MAX_LATE_IRQ); + saved_percpu_irqs[saved_irq_cnt].irq = vec; + saved_percpu_irqs[saved_irq_cnt].action = action; + saved_irq_cnt++; + if (!xen_slab_ready) + late_irq_cnt++; + } +} + +static void +xen_register_percpu_irq(ia64_vector vec, struct irqaction *action) +{ + __xen_register_percpu_irq(smp_processor_id(), vec, action, 1); +} + +static void +xen_bind_early_percpu_irq(void) +{ + int i; + + xen_slab_ready = 1; + /* There's no race when accessing this cached array, since only + * BSP will face with such step shortly + */ + for (i = 0; i < late_irq_cnt; i++) + __xen_register_percpu_irq(smp_processor_id(), + saved_percpu_irqs[i].irq, + saved_percpu_irqs[i].action, 0); +} + +/* FIXME: There's no obvious point to check whether slab is ready. So + * a hack is used here by utilizing a late time hook. + */ + +#ifdef CONFIG_HOTPLUG_CPU +static int __devinit +unbind_evtchn_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + unsigned int cpu = (unsigned long)hcpu; + + if (action == CPU_DEAD) { + /* Unregister evtchn. */ + if (per_cpu(cpep_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(cpep_irq, cpu), NULL); + per_cpu(cpep_irq, cpu) = -1; + } + if (per_cpu(cmcp_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(cmcp_irq, cpu), NULL); + per_cpu(cmcp_irq, cpu) = -1; + } + if (per_cpu(cmc_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(cmc_irq, cpu), NULL); + per_cpu(cmc_irq, cpu) = -1; + } + if (per_cpu(ipi_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(ipi_irq, cpu), NULL); + per_cpu(ipi_irq, cpu) = -1; + } + if (per_cpu(resched_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(resched_irq, cpu), + NULL); + per_cpu(resched_irq, cpu) = -1; + } + if (per_cpu(timer_irq, cpu) >= 0) { + unbind_from_irqhandler(per_cpu(timer_irq, cpu), NULL); + per_cpu(timer_irq, cpu) = -1; + } + } + return NOTIFY_OK; +} + +static struct notifier_block unbind_evtchn_notifier = { + .notifier_call = unbind_evtchn_callback, + .priority = 0 +}; +#endif + +void xen_smp_intr_init_early(unsigned int cpu) +{ +#ifdef CONFIG_SMP + unsigned int i; + + for (i = 0; i < saved_irq_cnt; i++) + __xen_register_percpu_irq(cpu, saved_percpu_irqs[i].irq, + saved_percpu_irqs[i].action, 0); +#endif +} + +void xen_smp_intr_init(void) +{ +#ifdef CONFIG_SMP + unsigned int cpu = smp_processor_id(); + struct callback_register event = { + .type = CALLBACKTYPE_event, + .address = { .ip = (unsigned long)&xen_event_callback }, + }; + + if (cpu == 0) { + /* Initialization was already done for boot cpu. */ +#ifdef CONFIG_HOTPLUG_CPU + /* Register the notifier only once. */ + register_cpu_notifier(&unbind_evtchn_notifier); +#endif + return; + } + + /* This should be piggyback when setup vcpu guest context */ + BUG_ON(HYPERVISOR_callback_op(CALLBACKOP_register, &event)); +#endif /* CONFIG_SMP */ +} + +void __init +xen_irq_init(void) +{ + struct callback_register event = { + .type = CALLBACKTYPE_event, + .address = { .ip = (unsigned long)&xen_event_callback }, + }; + + xen_init_IRQ(); + BUG_ON(HYPERVISOR_callback_op(CALLBACKOP_register, &event)); + late_time_init = xen_bind_early_percpu_irq; +} + +void +xen_platform_send_ipi(int cpu, int vector, int delivery_mode, int redirect) +{ +#ifdef CONFIG_SMP + /* TODO: we need to call vcpu_up here */ + if (unlikely(vector == ap_wakeup_vector)) { + /* XXX + * This should be in __cpu_up(cpu) in ia64 smpboot.c + * like x86. But don't want to modify it, + * keep it untouched. + */ + xen_smp_intr_init_early(cpu); + + xen_send_ipi(cpu, vector); + /* vcpu_prepare_and_up(cpu); */ + return; + } +#endif + + switch (vector) { + case IA64_IPI_VECTOR: + xen_send_IPI_one(cpu, XEN_IPI_VECTOR); + break; + case IA64_IPI_RESCHEDULE: + xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); + break; + case IA64_CMCP_VECTOR: + xen_send_IPI_one(cpu, XEN_CMCP_VECTOR); + break; + case IA64_CPEP_VECTOR: + xen_send_IPI_one(cpu, XEN_CPEP_VECTOR); + break; + case IA64_TIMER_VECTOR: { + /* this is used only once by check_sal_cache_flush() + at boot time */ + static int used = 0; + if (!used) { + xen_send_ipi(cpu, IA64_TIMER_VECTOR); + used = 1; + break; + } + /* fallthrough */ + } + default: + printk(KERN_WARNING "Unsupported IPI type 0x%x\n", + vector); + notify_remote_via_irq(0); /* defaults to 0 irq */ + break; + } +} + +static void __init +xen_register_ipi(void) +{ +#ifdef CONFIG_SMP + register_percpu_irq(IA64_IPI_VECTOR, &xen_ipi_irqaction); + register_percpu_irq(IA64_IPI_RESCHEDULE, &xen_resched_irqaction); + register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &xen_tlb_irqaction); +#endif +} + +static void +xen_resend_irq(unsigned int vector) +{ + (void)resend_irq_on_evtchn(vector); +} + +const struct pv_irq_ops xen_irq_ops __initdata = { + .register_ipi = xen_register_ipi, + + .assign_irq_vector = xen_assign_irq_vector, + .free_irq_vector = xen_free_irq_vector, + .register_percpu_irq = xen_register_percpu_irq, + + .resend_irq = xen_resend_irq, +}; diff --git a/arch/ia64/xen/irq_xen.h b/arch/ia64/xen/irq_xen.h new file mode 100644 index 0000000..26110f3 --- /dev/null +++ b/arch/ia64/xen/irq_xen.h @@ -0,0 +1,34 @@ +/****************************************************************************** + * arch/ia64/xen/irq_xen.h + * + * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp> + * VA Linux Systems Japan K.K. + * + * 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. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#ifndef IRQ_XEN_H +#define IRQ_XEN_H + +extern void (*late_time_init)(void); +extern char xen_event_callback; +void __init xen_init_IRQ(void); + +extern const struct pv_irq_ops xen_irq_ops __initdata; +extern void xen_smp_intr_init(void); +extern void xen_send_ipi(int cpu, int vec); + +#endif /* IRQ_XEN_H */ diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c index 41a6cbf..4fe4e62 100644 --- a/arch/ia64/xen/xen_pv_ops.c +++ b/arch/ia64/xen/xen_pv_ops.c @@ -29,6 +29,8 @@ #include <asm/xen/xencomm.h> #include <asm/xen/privop.h> +#include "irq_xen.h" + /*************************************************************************** * general info */ @@ -354,6 +356,7 @@ xen_setup_pv_ops(void) pv_init_ops = xen_init_ops; pv_cpu_ops = xen_cpu_ops; pv_iosapic_ops = xen_iosapic_ops; + pv_irq_ops = xen_irq_ops; paravirt_cpu_asm_init(&xen_cpu_asm_switch); } -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
![]() |