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    Subject[PATCH v2 11/21] x86/xen: split off smp_pv.c
    Date
    Basically, smp.c is renamed to smp_pv.c and some code moved out to common
    smp.c. struct xen_common_irq delcaration ended up in smp.h.

    Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
    ---
    arch/x86/xen/Makefile | 2 +-
    arch/x86/xen/smp.c | 487 +-----------------------------------------------
    arch/x86/xen/smp.h | 5 +
    arch/x86/xen/smp_pv.c | 499 ++++++++++++++++++++++++++++++++++++++++++++++++++
    4 files changed, 508 insertions(+), 485 deletions(-)
    create mode 100644 arch/x86/xen/smp_pv.c

    diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
    index bc7df8c..ebf3522 100644
    --- a/arch/x86/xen/Makefile
    +++ b/arch/x86/xen/Makefile
    @@ -20,7 +20,7 @@ obj-$(CONFIG_XEN_PVH) += enlighten_pvh.o

    obj-$(CONFIG_EVENT_TRACING) += trace.o

    -obj-$(CONFIG_SMP) += smp.o
    +obj-$(CONFIG_SMP) += smp.o smp_pv.o
    obj-$(CONFIG_XEN_PVHVM_SMP) += smp_hvm.o
    obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
    obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o
    diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
    index c692336..82ac611 100644
    --- a/arch/x86/xen/smp.c
    +++ b/arch/x86/xen/smp.c
    @@ -1,62 +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 <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.
    @@ -69,42 +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) {
    @@ -134,23 +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;
    @@ -208,360 +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_table(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);
    @@ -696,36 +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();
    -}
    diff --git a/arch/x86/xen/smp.h b/arch/x86/xen/smp.h
    index bf36e79..3245343 100644
    --- a/arch/x86/xen/smp.h
    +++ b/arch/x86/xen/smp.h
    @@ -17,6 +17,11 @@ extern void xen_smp_intr_free_pv(unsigned int cpu);
    extern void xen_smp_send_reschedule(int cpu);
    extern void xen_smp_send_call_function_ipi(const struct cpumask *mask);
    extern void xen_smp_send_call_function_single_ipi(int cpu);
    +
    +struct xen_common_irq {
    + int irq;
    + char *name;
    +};
    #else /* CONFIG_SMP */

    static inline int xen_smp_intr_init(unsigned int cpu)
    diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
    new file mode 100644
    index 0000000..e20718a
    --- /dev/null
    +++ b/arch/x86/xen/smp_pv.c
    @@ -0,0 +1,499 @@
    +/*
    + * 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 <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 <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;
    +
    +static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
    +static DEFINE_PER_CPU(struct xen_common_irq, xen_pmu_irq) = { .irq = -1 };
    +
    +static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
    +
    +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_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_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_table(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);
    +}
    +
    +static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
    +{
    + irq_enter();
    + generic_smp_call_function_interrupt();
    + inc_irq_stat(irq_call_count);
    + irq_exit();
    +
    + 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();
    +}
    --
    2.9.3
    \
     
     \ /
      Last update: 2017-03-02 19:13    [W:2.551 / U:0.380 seconds]
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