diff options
Diffstat (limited to 'arch/i386/xen/smp.c')
| -rw-r--r-- | arch/i386/xen/smp.c | 404 |
1 files changed, 0 insertions, 404 deletions
diff --git a/arch/i386/xen/smp.c b/arch/i386/xen/smp.c deleted file mode 100644 index 557b8e2..0000000 --- a/arch/i386/xen/smp.c +++ /dev/null @@ -1,404 +0,0 @@ -/* - * 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. - * - * This does not handle HOTPLUG_CPU yet. - */ -#include <linux/sched.h> -#include <linux/err.h> -#include <linux/smp.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 <asm/xen/interface.h> -#include <asm/xen/hypercall.h> - -#include <xen/page.h> -#include <xen/events.h> - -#include "xen-ops.h" -#include "mmu.h" - -static cpumask_t cpu_initialized_map; -static DEFINE_PER_CPU(int, resched_irq); -static DEFINE_PER_CPU(int, callfunc_irq); - -/* - * Structure and data for smp_call_function(). This is designed to minimise - * static memory requirements. It also looks cleaner. - */ -static DEFINE_SPINLOCK(call_lock); - -struct call_data_struct { - void (*func) (void *info); - void *info; - atomic_t started; - atomic_t finished; - int wait; -}; - -static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id); - -static struct call_data_struct *call_data; - -/* - * Reschedule call back. Nothing to do, - * all the work is done automatically when - * we return from the interrupt. - */ -static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id) -{ - return IRQ_HANDLED; -} - -static __cpuinit void cpu_bringup_and_idle(void) -{ - int cpu = smp_processor_id(); - - cpu_init(); - - preempt_disable(); - per_cpu(cpu_state, cpu) = CPU_ONLINE; - - xen_setup_cpu_clockevents(); - - /* We can take interrupts now: we're officially "up". */ - local_irq_enable(); - - wmb(); /* make sure everything is out */ - cpu_idle(); -} - -static int xen_smp_intr_init(unsigned int cpu) -{ - int rc; - const char *resched_name, *callfunc_name; - - per_cpu(resched_irq, cpu) = per_cpu(callfunc_irq, cpu) = -1; - - resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu); - rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, - cpu, - xen_reschedule_interrupt, - IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, - resched_name, - NULL); - if (rc < 0) - goto fail; - per_cpu(resched_irq, cpu) = rc; - - callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu); - rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR, - cpu, - xen_call_function_interrupt, - IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, - callfunc_name, - NULL); - if (rc < 0) - goto fail; - per_cpu(callfunc_irq, cpu) = rc; - - return 0; - - fail: - if (per_cpu(resched_irq, cpu) >= 0) - unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); - if (per_cpu(callfunc_irq, cpu) >= 0) - unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); - return rc; -} - -void __init xen_fill_possible_map(void) -{ - int i, rc; - - for (i = 0; i < NR_CPUS; i++) { - rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); - if (rc >= 0) - cpu_set(i, cpu_possible_map); - } -} - -void __init xen_smp_prepare_boot_cpu(void) -{ - int cpu; - - BUG_ON(smp_processor_id() != 0); - native_smp_prepare_boot_cpu(); - - /* We've switched to the "real" per-cpu gdt, so make sure the - old memory can be recycled */ - make_lowmem_page_readwrite(&per_cpu__gdt_page); - - for (cpu = 0; cpu < NR_CPUS; cpu++) { - cpus_clear(cpu_sibling_map[cpu]); - cpus_clear(cpu_core_map[cpu]); - } - - xen_setup_vcpu_info_placement(); -} - -void __init xen_smp_prepare_cpus(unsigned int max_cpus) -{ - unsigned cpu; - - for (cpu = 0; cpu < NR_CPUS; cpu++) { - cpus_clear(cpu_sibling_map[cpu]); - cpus_clear(cpu_core_map[cpu]); - } - - smp_store_cpu_info(0); - set_cpu_sibling_map(0); - - if (xen_smp_intr_init(0)) - BUG(); - - cpu_initialized_map = cpumask_of_cpu(0); - - /* Restrict the possible_map according to max_cpus. */ - while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { - for (cpu = NR_CPUS-1; !cpu_isset(cpu, cpu_possible_map); cpu--) - continue; - cpu_clear(cpu, cpu_possible_map); - } - - for_each_possible_cpu (cpu) { - struct task_struct *idle; - - if (cpu == 0) - continue; - - idle = fork_idle(cpu); - if (IS_ERR(idle)) - panic("failed fork for CPU %d", cpu); - - cpu_set(cpu, cpu_present_map); - } - - //init_xenbus_allowed_cpumask(); -} - -static __cpuinit int -cpu_initialize_context(unsigned int cpu, struct task_struct *idle) -{ - struct vcpu_guest_context *ctxt; - struct gdt_page *gdt = &per_cpu(gdt_page, cpu); - - if (cpu_test_and_set(cpu, cpu_initialized_map)) - return 0; - - ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL); - if (ctxt == NULL) - return -ENOMEM; - - ctxt->flags = VGCF_IN_KERNEL; - ctxt->user_regs.ds = __USER_DS; - ctxt->user_regs.es = __USER_DS; - ctxt->user_regs.fs = __KERNEL_PERCPU; - ctxt->user_regs.gs = 0; - ctxt->user_regs.ss = __KERNEL_DS; - ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; - ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ - - memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); - - xen_copy_trap_info(ctxt->trap_ctxt); - - ctxt->ldt_ents = 0; - - BUG_ON((unsigned long)gdt->gdt & ~PAGE_MASK); - make_lowmem_page_readonly(gdt->gdt); - - ctxt->gdt_frames[0] = virt_to_mfn(gdt->gdt); - ctxt->gdt_ents = ARRAY_SIZE(gdt->gdt); - - ctxt->user_regs.cs = __KERNEL_CS; - ctxt->user_regs.esp = idle->thread.esp0 - sizeof(struct pt_regs); - - ctxt->kernel_ss = __KERNEL_DS; - ctxt->kernel_sp = idle->thread.esp0; - - ctxt->event_callback_cs = __KERNEL_CS; - ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback; - ctxt->failsafe_callback_cs = __KERNEL_CS; - ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback; - - per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); - ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); - - if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt)) - BUG(); - - kfree(ctxt); - return 0; -} - -int __cpuinit xen_cpu_up(unsigned int cpu) -{ - struct task_struct *idle = idle_task(cpu); - int rc; - -#if 0 - rc = cpu_up_check(cpu); - if (rc) - return rc; -#endif - - init_gdt(cpu); - per_cpu(current_task, cpu) = idle; - irq_ctx_init(cpu); - xen_setup_timer(cpu); - - /* make sure interrupts start blocked */ - per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; - - rc = cpu_initialize_context(cpu, idle); - if (rc) - return rc; - - if (num_online_cpus() == 1) - alternatives_smp_switch(1); - - rc = xen_smp_intr_init(cpu); - if (rc) - return rc; - - smp_store_cpu_info(cpu); - set_cpu_sibling_map(cpu); - /* This must be done before setting cpu_online_map */ - wmb(); - - cpu_set(cpu, cpu_online_map); - - rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); - BUG_ON(rc); - - return 0; -} - -void xen_smp_cpus_done(unsigned int max_cpus) -{ -} - -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 */ - - HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL); - BUG(); -} - -void xen_smp_send_stop(void) -{ - smp_call_function(stop_self, NULL, 0, 0); -} - -void xen_smp_send_reschedule(int cpu) -{ - xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); -} - - -static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector) -{ - unsigned cpu; - - cpus_and(mask, mask, cpu_online_map); - - for_each_cpu_mask(cpu, mask) - xen_send_IPI_one(cpu, vector); -} - -static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) -{ - void (*func) (void *info) = call_data->func; - void *info = call_data->info; - int wait = call_data->wait; - - /* - * Notify initiating CPU that I've grabbed the data and am - * about to execute the function - */ - mb(); - atomic_inc(&call_data->started); - /* - * At this point the info structure may be out of scope unless wait==1 - */ - irq_enter(); - (*func)(info); - irq_exit(); - - if (wait) { - mb(); /* commit everything before setting finished */ - atomic_inc(&call_data->finished); - } - - return IRQ_HANDLED; -} - -int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *), - void *info, int wait) -{ - struct call_data_struct data; - int cpus; - - /* Holding any lock stops cpus from going down. */ - spin_lock(&call_lock); - - cpu_clear(smp_processor_id(), mask); - - cpus = cpus_weight(mask); - if (!cpus) { - spin_unlock(&call_lock); - return 0; - } - - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - - data.func = func; - data.info = info; - atomic_set(&data.started, 0); - data.wait = wait; - if (wait) - atomic_set(&data.finished, 0); - - call_data = &data; - mb(); /* write everything before IPI */ - - /* Send a message to other CPUs and wait for them to respond */ - xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); - - /* Make sure other vcpus get a chance to run. - XXX too severe? Maybe we should check the other CPU's states? */ - HYPERVISOR_sched_op(SCHEDOP_yield, 0); - - /* Wait for response */ - while (atomic_read(&data.started) != cpus || - (wait && atomic_read(&data.finished) != cpus)) - cpu_relax(); - - spin_unlock(&call_lock); - - return 0; -} |
