diff options
Diffstat (limited to 'arch/x86/xen/smp.c')
-rw-r--r-- | arch/x86/xen/smp.c | 488 |
1 files changed, 3 insertions, 485 deletions
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 148e62cfc22f..82ac611f2fc1 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -1,63 +1,21 @@ -/* - * Xen SMP support - * - * This file implements the Xen versions of smp_ops. SMP under Xen is - * very straightforward. Bringing a CPU up is simply a matter of - * loading its initial context and setting it running. - * - * IPIs are handled through the Xen event mechanism. - * - * Because virtual CPUs can be scheduled onto any real CPU, there's no - * useful topology information for the kernel to make use of. As a - * result, all CPUs are treated as if they're single-core and - * single-threaded. - */ -#include <linux/sched.h> -#include <linux/err.h> -#include <linux/slab.h> #include <linux/smp.h> -#include <linux/irq_work.h> -#include <linux/tick.h> -#include <linux/nmi.h> - -#include <asm/paravirt.h> -#include <asm/desc.h> -#include <asm/pgtable.h> -#include <asm/cpu.h> - -#include <xen/interface/xen.h> -#include <xen/interface/vcpu.h> -#include <xen/interface/xenpmu.h> - -#include <asm/xen/interface.h> -#include <asm/xen/hypercall.h> +#include <linux/slab.h> +#include <linux/cpumask.h> +#include <linux/percpu.h> -#include <xen/xen.h> -#include <xen/page.h> #include <xen/events.h> #include <xen/hvc-console.h> #include "xen-ops.h" -#include "mmu.h" #include "smp.h" -#include "pmu.h" - -cpumask_var_t xen_cpu_initialized_map; -struct xen_common_irq { - int irq; - char *name; -}; static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 }; static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 }; static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 }; -static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 }; static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 }; -static DEFINE_PER_CPU(struct xen_common_irq, xen_pmu_irq) = { .irq = -1 }; static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id); static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id); -static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id); /* * Reschedule call back. @@ -70,42 +28,6 @@ static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static void cpu_bringup(void) -{ - int cpu; - - cpu_init(); - touch_softlockup_watchdog(); - preempt_disable(); - - /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */ - if (!xen_feature(XENFEAT_supervisor_mode_kernel)) { - xen_enable_sysenter(); - xen_enable_syscall(); - } - cpu = smp_processor_id(); - smp_store_cpu_info(cpu); - cpu_data(cpu).x86_max_cores = 1; - set_cpu_sibling_map(cpu); - - xen_setup_cpu_clockevents(); - - notify_cpu_starting(cpu); - - set_cpu_online(cpu, true); - - cpu_set_state_online(cpu); /* Implies full memory barrier. */ - - /* We can take interrupts now: we're officially "up". */ - local_irq_enable(); -} - -asmlinkage __visible void cpu_bringup_and_idle(void) -{ - cpu_bringup(); - cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); -} - void xen_smp_intr_free(unsigned int cpu) { if (per_cpu(xen_resched_irq, cpu).irq >= 0) { @@ -135,23 +57,6 @@ void xen_smp_intr_free(unsigned int cpu) } } -void xen_smp_intr_free_pv(unsigned int cpu) -{ - if (per_cpu(xen_irq_work, cpu).irq >= 0) { - unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL); - per_cpu(xen_irq_work, cpu).irq = -1; - kfree(per_cpu(xen_irq_work, cpu).name); - per_cpu(xen_irq_work, cpu).name = NULL; - } - - if (per_cpu(xen_pmu_irq, cpu).irq >= 0) { - unbind_from_irqhandler(per_cpu(xen_pmu_irq, cpu).irq, NULL); - per_cpu(xen_pmu_irq, cpu).irq = -1; - kfree(per_cpu(xen_pmu_irq, cpu).name); - per_cpu(xen_pmu_irq, cpu).name = NULL; - } -} - int xen_smp_intr_init(unsigned int cpu) { int rc; @@ -209,360 +114,6 @@ int xen_smp_intr_init(unsigned int cpu) return rc; } -int xen_smp_intr_init_pv(unsigned int cpu) -{ - int rc; - char *callfunc_name, *pmu_name; - - callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu); - rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR, - cpu, - xen_irq_work_interrupt, - IRQF_PERCPU|IRQF_NOBALANCING, - callfunc_name, - NULL); - if (rc < 0) - goto fail; - per_cpu(xen_irq_work, cpu).irq = rc; - per_cpu(xen_irq_work, cpu).name = callfunc_name; - - if (is_xen_pmu(cpu)) { - pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu); - rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu, - xen_pmu_irq_handler, - IRQF_PERCPU|IRQF_NOBALANCING, - pmu_name, NULL); - if (rc < 0) - goto fail; - per_cpu(xen_pmu_irq, cpu).irq = rc; - per_cpu(xen_pmu_irq, cpu).name = pmu_name; - } - - return 0; - - fail: - xen_smp_intr_free_pv(cpu); - return rc; -} - -static void __init xen_fill_possible_map(void) -{ - int i, rc; - - if (xen_initial_domain()) - return; - - for (i = 0; i < nr_cpu_ids; i++) { - rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); - if (rc >= 0) { - num_processors++; - set_cpu_possible(i, true); - } - } -} - -static void __init xen_filter_cpu_maps(void) -{ - int i, rc; - unsigned int subtract = 0; - - if (!xen_initial_domain()) - return; - - num_processors = 0; - disabled_cpus = 0; - for (i = 0; i < nr_cpu_ids; i++) { - rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); - if (rc >= 0) { - num_processors++; - set_cpu_possible(i, true); - } else { - set_cpu_possible(i, false); - set_cpu_present(i, false); - subtract++; - } - } -#ifdef CONFIG_HOTPLUG_CPU - /* This is akin to using 'nr_cpus' on the Linux command line. - * Which is OK as when we use 'dom0_max_vcpus=X' we can only - * have up to X, while nr_cpu_ids is greater than X. This - * normally is not a problem, except when CPU hotplugging - * is involved and then there might be more than X CPUs - * in the guest - which will not work as there is no - * hypercall to expand the max number of VCPUs an already - * running guest has. So cap it up to X. */ - if (subtract) - nr_cpu_ids = nr_cpu_ids - subtract; -#endif - -} - -static void __init xen_pv_smp_prepare_boot_cpu(void) -{ - BUG_ON(smp_processor_id() != 0); - native_smp_prepare_boot_cpu(); - - if (!xen_feature(XENFEAT_writable_page_tables)) - /* We've switched to the "real" per-cpu gdt, so make - * sure the old memory can be recycled. */ - make_lowmem_page_readwrite(xen_initial_gdt); - -#ifdef CONFIG_X86_32 - /* - * Xen starts us with XEN_FLAT_RING1_DS, but linux code - * expects __USER_DS - */ - loadsegment(ds, __USER_DS); - loadsegment(es, __USER_DS); -#endif - - xen_filter_cpu_maps(); - xen_setup_vcpu_info_placement(); - - /* - * The alternative logic (which patches the unlock/lock) runs before - * the smp bootup up code is activated. Hence we need to set this up - * the core kernel is being patched. Otherwise we will have only - * modules patched but not core code. - */ - xen_init_spinlocks(); -} - -static void __init xen_smp_prepare_cpus(unsigned int max_cpus) -{ - unsigned cpu; - unsigned int i; - - if (skip_ioapic_setup) { - char *m = (max_cpus == 0) ? - "The nosmp parameter is incompatible with Xen; " \ - "use Xen dom0_max_vcpus=1 parameter" : - "The noapic parameter is incompatible with Xen"; - - xen_raw_printk(m); - panic(m); - } - xen_init_lock_cpu(0); - - smp_store_boot_cpu_info(); - cpu_data(0).x86_max_cores = 1; - - for_each_possible_cpu(i) { - zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); - zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); - zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL); - } - set_cpu_sibling_map(0); - - xen_pmu_init(0); - - if (xen_smp_intr_init(0)) - BUG(); - - if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL)) - panic("could not allocate xen_cpu_initialized_map\n"); - - cpumask_copy(xen_cpu_initialized_map, cpumask_of(0)); - - /* Restrict the possible_map according to max_cpus. */ - while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { - for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--) - continue; - set_cpu_possible(cpu, false); - } - - for_each_possible_cpu(cpu) - set_cpu_present(cpu, true); -} - -static int -cpu_initialize_context(unsigned int cpu, struct task_struct *idle) -{ - struct vcpu_guest_context *ctxt; - struct desc_struct *gdt; - unsigned long gdt_mfn; - - /* used to tell cpu_init() that it can proceed with initialization */ - cpumask_set_cpu(cpu, cpu_callout_mask); - if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map)) - return 0; - - ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL); - if (ctxt == NULL) - return -ENOMEM; - - gdt = get_cpu_gdt_rw(cpu); - -#ifdef CONFIG_X86_32 - ctxt->user_regs.fs = __KERNEL_PERCPU; - ctxt->user_regs.gs = __KERNEL_STACK_CANARY; -#endif - memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); - - ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; - ctxt->flags = VGCF_IN_KERNEL; - ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ - ctxt->user_regs.ds = __USER_DS; - ctxt->user_regs.es = __USER_DS; - ctxt->user_regs.ss = __KERNEL_DS; - - xen_copy_trap_info(ctxt->trap_ctxt); - - ctxt->ldt_ents = 0; - - BUG_ON((unsigned long)gdt & ~PAGE_MASK); - - gdt_mfn = arbitrary_virt_to_mfn(gdt); - make_lowmem_page_readonly(gdt); - make_lowmem_page_readonly(mfn_to_virt(gdt_mfn)); - - ctxt->gdt_frames[0] = gdt_mfn; - ctxt->gdt_ents = GDT_ENTRIES; - - ctxt->kernel_ss = __KERNEL_DS; - ctxt->kernel_sp = idle->thread.sp0; - -#ifdef CONFIG_X86_32 - ctxt->event_callback_cs = __KERNEL_CS; - ctxt->failsafe_callback_cs = __KERNEL_CS; -#else - ctxt->gs_base_kernel = per_cpu_offset(cpu); -#endif - ctxt->event_callback_eip = - (unsigned long)xen_hypervisor_callback; - ctxt->failsafe_callback_eip = - (unsigned long)xen_failsafe_callback; - ctxt->user_regs.cs = __KERNEL_CS; - per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); - - ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); - ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir)); - if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt)) - BUG(); - - kfree(ctxt); - return 0; -} - -static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) -{ - int rc; - - common_cpu_up(cpu, idle); - - xen_setup_runstate_info(cpu); - - /* - * PV VCPUs are always successfully taken down (see 'while' loop - * in xen_cpu_die()), so -EBUSY is an error. - */ - rc = cpu_check_up_prepare(cpu); - if (rc) - return rc; - - /* make sure interrupts start blocked */ - per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; - - rc = cpu_initialize_context(cpu, idle); - if (rc) - return rc; - - xen_pmu_init(cpu); - - rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL); - BUG_ON(rc); - - while (cpu_report_state(cpu) != CPU_ONLINE) - HYPERVISOR_sched_op(SCHEDOP_yield, NULL); - - return 0; -} - -static void xen_smp_cpus_done(unsigned int max_cpus) -{ -} - -#ifdef CONFIG_HOTPLUG_CPU -static int xen_cpu_disable(void) -{ - unsigned int cpu = smp_processor_id(); - if (cpu == 0) - return -EBUSY; - - cpu_disable_common(); - - load_cr3(swapper_pg_dir); - return 0; -} - -static void xen_pv_cpu_die(unsigned int cpu) -{ - while (HYPERVISOR_vcpu_op(VCPUOP_is_up, - xen_vcpu_nr(cpu), NULL)) { - __set_current_state(TASK_UNINTERRUPTIBLE); - schedule_timeout(HZ/10); - } - - if (common_cpu_die(cpu) == 0) { - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - xen_teardown_timer(cpu); - xen_pmu_finish(cpu); - } -} - -static void xen_play_dead(void) /* used only with HOTPLUG_CPU */ -{ - play_dead_common(); - HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(smp_processor_id()), NULL); - cpu_bringup(); - /* - * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down) - * clears certain data that the cpu_idle loop (which called us - * and that we return from) expects. The only way to get that - * data back is to call: - */ - tick_nohz_idle_enter(); - - cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); -} - -#else /* !CONFIG_HOTPLUG_CPU */ -static int xen_cpu_disable(void) -{ - return -ENOSYS; -} - -static void xen_pv_cpu_die(unsigned int cpu) -{ - BUG(); -} - -static void xen_play_dead(void) -{ - BUG(); -} - -#endif -static void stop_self(void *v) -{ - int cpu = smp_processor_id(); - - /* make sure we're not pinning something down */ - load_cr3(swapper_pg_dir); - /* should set up a minimal gdt */ - - set_cpu_online(cpu, false); - - HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL); - BUG(); -} - -static void xen_stop_other_cpus(int wait) -{ - smp_call_function(stop_self, NULL, wait); -} - void xen_smp_send_reschedule(int cpu) { xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); @@ -697,36 +248,3 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } - -static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id) -{ - irq_enter(); - irq_work_run(); - inc_irq_stat(apic_irq_work_irqs); - irq_exit(); - - return IRQ_HANDLED; -} - -static const struct smp_ops xen_smp_ops __initconst = { - .smp_prepare_boot_cpu = xen_pv_smp_prepare_boot_cpu, - .smp_prepare_cpus = xen_smp_prepare_cpus, - .smp_cpus_done = xen_smp_cpus_done, - - .cpu_up = xen_cpu_up, - .cpu_die = xen_pv_cpu_die, - .cpu_disable = xen_cpu_disable, - .play_dead = xen_play_dead, - - .stop_other_cpus = xen_stop_other_cpus, - .smp_send_reschedule = xen_smp_send_reschedule, - - .send_call_func_ipi = xen_smp_send_call_function_ipi, - .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, -}; - -void __init xen_smp_init(void) -{ - smp_ops = xen_smp_ops; - xen_fill_possible_map(); -} |