From: Boris Ostrovsky Date: Wed, 3 Aug 2016 17:22:27 +0000 (-0400) Subject: xen/x86: Move irq allocation from Xen smp_op.cpu_up() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5fc509bc2bd6dddd4107eaf90680cd76cfc2ffed;p=linux-beck.git xen/x86: Move irq allocation from Xen smp_op.cpu_up() Commit ce0d3c0a6fb1 ("genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now") reverted irq locking introduced by commit a89941816726 ("hotplug: Prevent alloc/free of irq descriptors during cpu up/down") because of Xen allocating irqs in both of its cpu_up ops. We can move those allocations into CPU notifiers so that original patch can be reinstated. Signed-off-by: Boris Ostrovsky Signed-off-by: David Vrabel --- diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 8ffb089b19a5..c7f6b1f90efa 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -140,6 +140,8 @@ RESERVE_BRK(shared_info_page_brk, PAGE_SIZE); __read_mostly int xen_have_vector_callback; EXPORT_SYMBOL_GPL(xen_have_vector_callback); +static struct notifier_block xen_cpu_notifier; + /* * Point at some empty memory to start with. We map the real shared_info * page as soon as fixmap is up and running. @@ -1627,6 +1629,7 @@ asmlinkage __visible void __init xen_start_kernel(void) xen_initial_gdt = &per_cpu(gdt_page, 0); xen_smp_init(); + register_cpu_notifier(&xen_cpu_notifier); #ifdef CONFIG_ACPI_NUMA /* @@ -1820,21 +1823,53 @@ static void __init init_hvm_pv_info(void) xen_domain_type = XEN_HVM_DOMAIN; } -static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action, - void *hcpu) +static int xen_cpu_notify(struct notifier_block *self, unsigned long action, + void *hcpu) { int cpu = (long)hcpu; + int rc; + switch (action) { case CPU_UP_PREPARE: - if (cpu_acpi_id(cpu) != U32_MAX) - per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); - else - per_cpu(xen_vcpu_id, cpu) = cpu; - xen_vcpu_setup(cpu); - if (xen_have_vector_callback) { - if (xen_feature(XENFEAT_hvm_safe_pvclock)) - xen_setup_timer(cpu); + if (xen_hvm_domain()) { + /* + * This can happen if CPU was offlined earlier and + * offlining timed out in common_cpu_die(). + */ + if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + } + + if (cpu_acpi_id(cpu) != U32_MAX) + per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); + else + per_cpu(xen_vcpu_id, cpu) = cpu; + xen_vcpu_setup(cpu); } + + if (xen_pv_domain() || + (xen_have_vector_callback && + xen_feature(XENFEAT_hvm_safe_pvclock))) + xen_setup_timer(cpu); + + rc = xen_smp_intr_init(cpu); + if (rc) { + WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", + cpu, rc); + return NOTIFY_BAD; + } + + break; + case CPU_ONLINE: + xen_init_lock_cpu(cpu); + break; + case CPU_UP_CANCELED: + xen_smp_intr_free(cpu); + if (xen_pv_domain() || + (xen_have_vector_callback && + xen_feature(XENFEAT_hvm_safe_pvclock))) + xen_teardown_timer(cpu); break; default: break; @@ -1842,8 +1877,8 @@ static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action, return NOTIFY_OK; } -static struct notifier_block xen_hvm_cpu_notifier = { - .notifier_call = xen_hvm_cpu_notify, +static struct notifier_block xen_cpu_notifier = { + .notifier_call = xen_cpu_notify, }; #ifdef CONFIG_KEXEC_CORE @@ -1875,7 +1910,7 @@ static void __init xen_hvm_guest_init(void) if (xen_feature(XENFEAT_hvm_callback_vector)) xen_have_vector_callback = 1; xen_hvm_smp_init(); - register_cpu_notifier(&xen_hvm_cpu_notifier); + register_cpu_notifier(&xen_cpu_notifier); xen_unplug_emulated_devices(); x86_init.irqs.intr_init = xen_init_IRQ; xen_hvm_init_time_ops(); diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 0b4d04c8ab4d..137afbbd0590 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -115,7 +115,7 @@ asmlinkage __visible void cpu_bringup_and_idle(int cpu) cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } -static void xen_smp_intr_free(unsigned int cpu) +void xen_smp_intr_free(unsigned int cpu) { if (per_cpu(xen_resched_irq, cpu).irq >= 0) { unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL); @@ -159,7 +159,7 @@ static void xen_smp_intr_free(unsigned int cpu) per_cpu(xen_pmu_irq, cpu).name = NULL; } }; -static int xen_smp_intr_init(unsigned int cpu) +int xen_smp_intr_init(unsigned int cpu) { int rc; char *resched_name, *callfunc_name, *debug_name, *pmu_name; @@ -475,8 +475,6 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) common_cpu_up(cpu, idle); xen_setup_runstate_info(cpu); - xen_setup_timer(cpu); - xen_init_lock_cpu(cpu); /* * PV VCPUs are always successfully taken down (see 'while' loop @@ -495,10 +493,6 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) xen_pmu_init(cpu); - rc = xen_smp_intr_init(cpu); - if (rc) - return rc; - rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL); BUG_ON(rc); @@ -769,47 +763,12 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) xen_init_lock_cpu(0); } -static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle) -{ - int rc; - - /* - * This can happen if CPU was offlined earlier and - * offlining timed out in common_cpu_die(). - */ - if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - } - - /* - * xen_smp_intr_init() needs to run before native_cpu_up() - * so that IPI vectors are set up on the booting CPU before - * it is marked online in native_cpu_up(). - */ - rc = xen_smp_intr_init(cpu); - WARN_ON(rc); - if (!rc) - rc = native_cpu_up(cpu, tidle); - - /* - * We must initialize the slowpath CPU kicker _after_ the native - * path has executed. If we initialized it before none of the - * unlocker IPI kicks would reach the booting CPU as the booting - * CPU had not set itself 'online' in cpu_online_mask. That mask - * is checked when IPIs are sent (on HVM at least). - */ - xen_init_lock_cpu(cpu); - return rc; -} - void __init xen_hvm_smp_init(void) { if (!xen_have_vector_callback) return; smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus; smp_ops.smp_send_reschedule = xen_smp_send_reschedule; - smp_ops.cpu_up = xen_hvm_cpu_up; smp_ops.cpu_die = xen_cpu_die; smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi; smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi; diff --git a/arch/x86/xen/smp.h b/arch/x86/xen/smp.h index 963d62a35c82..c5c16dc4f694 100644 --- a/arch/x86/xen/smp.h +++ b/arch/x86/xen/smp.h @@ -1,5 +1,6 @@ #ifndef _XEN_SMP_H +#ifdef CONFIG_SMP extern void xen_send_IPI_mask(const struct cpumask *mask, int vector); extern void xen_send_IPI_mask_allbutself(const struct cpumask *mask, @@ -8,6 +9,18 @@ extern void xen_send_IPI_allbutself(int vector); extern void xen_send_IPI_all(int vector); extern void xen_send_IPI_self(int vector); +extern int xen_smp_intr_init(unsigned int cpu); +extern void xen_smp_intr_free(unsigned int cpu); + +#else /* CONFIG_SMP */ + +static inline int xen_smp_intr_init(unsigned int cpu) +{ + return 0; +} +static inline void xen_smp_intr_free(unsigned int cpu) {} +#endif /* CONFIG_SMP */ + #ifdef CONFIG_XEN_PVH extern void xen_pvh_early_cpu_init(int cpu, bool entry); #else