faca62273b
This changes size-specific register names (eip/rip, esp/rsp, etc.) to generic names in the thread and tss structures. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
422 lines
9.2 KiB
C
422 lines
9.2 KiB
C
/*
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* Xen SMP support
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*
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* This file implements the Xen versions of smp_ops. SMP under Xen is
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* very straightforward. Bringing a CPU up is simply a matter of
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* loading its initial context and setting it running.
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*
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* IPIs are handled through the Xen event mechanism.
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*
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* Because virtual CPUs can be scheduled onto any real CPU, there's no
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* useful topology information for the kernel to make use of. As a
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* result, all CPUs are treated as if they're single-core and
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* single-threaded.
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*
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* This does not handle HOTPLUG_CPU yet.
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*/
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#include <linux/sched.h>
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#include <linux/err.h>
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#include <linux/smp.h>
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#include <asm/paravirt.h>
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#include <asm/desc.h>
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#include <asm/pgtable.h>
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#include <asm/cpu.h>
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#include <xen/interface/xen.h>
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#include <xen/interface/vcpu.h>
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#include <asm/xen/interface.h>
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#include <asm/xen/hypercall.h>
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#include <xen/page.h>
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#include <xen/events.h>
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#include "xen-ops.h"
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#include "mmu.h"
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static cpumask_t cpu_initialized_map;
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static DEFINE_PER_CPU(int, resched_irq);
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static DEFINE_PER_CPU(int, callfunc_irq);
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/*
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* Structure and data for smp_call_function(). This is designed to minimise
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* static memory requirements. It also looks cleaner.
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*/
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static DEFINE_SPINLOCK(call_lock);
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struct call_data_struct {
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void (*func) (void *info);
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void *info;
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atomic_t started;
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atomic_t finished;
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int wait;
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};
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static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
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static struct call_data_struct *call_data;
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/*
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* Reschedule call back. Nothing to do,
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* all the work is done automatically when
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* we return from the interrupt.
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*/
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static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
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{
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return IRQ_HANDLED;
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}
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static __cpuinit void cpu_bringup_and_idle(void)
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{
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int cpu = smp_processor_id();
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cpu_init();
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preempt_disable();
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per_cpu(cpu_state, cpu) = CPU_ONLINE;
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xen_setup_cpu_clockevents();
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/* We can take interrupts now: we're officially "up". */
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local_irq_enable();
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wmb(); /* make sure everything is out */
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cpu_idle();
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}
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static int xen_smp_intr_init(unsigned int cpu)
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{
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int rc;
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const char *resched_name, *callfunc_name;
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per_cpu(resched_irq, cpu) = per_cpu(callfunc_irq, cpu) = -1;
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resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
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rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
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cpu,
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xen_reschedule_interrupt,
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IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
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resched_name,
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NULL);
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if (rc < 0)
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goto fail;
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per_cpu(resched_irq, cpu) = rc;
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callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
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rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
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cpu,
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xen_call_function_interrupt,
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IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
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callfunc_name,
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NULL);
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if (rc < 0)
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goto fail;
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per_cpu(callfunc_irq, cpu) = rc;
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return 0;
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fail:
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if (per_cpu(resched_irq, cpu) >= 0)
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unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL);
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if (per_cpu(callfunc_irq, cpu) >= 0)
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unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL);
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return rc;
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}
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void __init xen_fill_possible_map(void)
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{
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int i, rc;
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for (i = 0; i < NR_CPUS; i++) {
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rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
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if (rc >= 0)
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cpu_set(i, cpu_possible_map);
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}
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}
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void __init xen_smp_prepare_boot_cpu(void)
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{
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int cpu;
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BUG_ON(smp_processor_id() != 0);
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native_smp_prepare_boot_cpu();
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/* We've switched to the "real" per-cpu gdt, so make sure the
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old memory can be recycled */
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make_lowmem_page_readwrite(&per_cpu__gdt_page);
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for_each_possible_cpu(cpu) {
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cpus_clear(per_cpu(cpu_sibling_map, cpu));
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/*
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* cpu_core_map lives in a per cpu area that is cleared
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* when the per cpu array is allocated.
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*
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* cpus_clear(per_cpu(cpu_core_map, cpu));
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*/
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}
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xen_setup_vcpu_info_placement();
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}
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void __init xen_smp_prepare_cpus(unsigned int max_cpus)
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{
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unsigned cpu;
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for_each_possible_cpu(cpu) {
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cpus_clear(per_cpu(cpu_sibling_map, cpu));
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/*
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* cpu_core_ map will be zeroed when the per
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* cpu area is allocated.
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*
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* cpus_clear(per_cpu(cpu_core_map, cpu));
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*/
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}
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smp_store_cpu_info(0);
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set_cpu_sibling_map(0);
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if (xen_smp_intr_init(0))
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BUG();
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cpu_initialized_map = cpumask_of_cpu(0);
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/* Restrict the possible_map according to max_cpus. */
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while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
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for (cpu = NR_CPUS-1; !cpu_isset(cpu, cpu_possible_map); cpu--)
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continue;
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cpu_clear(cpu, cpu_possible_map);
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}
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for_each_possible_cpu (cpu) {
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struct task_struct *idle;
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if (cpu == 0)
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continue;
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idle = fork_idle(cpu);
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if (IS_ERR(idle))
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panic("failed fork for CPU %d", cpu);
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cpu_set(cpu, cpu_present_map);
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}
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//init_xenbus_allowed_cpumask();
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}
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static __cpuinit int
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cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
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{
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struct vcpu_guest_context *ctxt;
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struct gdt_page *gdt = &per_cpu(gdt_page, cpu);
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if (cpu_test_and_set(cpu, cpu_initialized_map))
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return 0;
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ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
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if (ctxt == NULL)
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return -ENOMEM;
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ctxt->flags = VGCF_IN_KERNEL;
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ctxt->user_regs.ds = __USER_DS;
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ctxt->user_regs.es = __USER_DS;
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ctxt->user_regs.fs = __KERNEL_PERCPU;
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ctxt->user_regs.gs = 0;
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ctxt->user_regs.ss = __KERNEL_DS;
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ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
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ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
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memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
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xen_copy_trap_info(ctxt->trap_ctxt);
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ctxt->ldt_ents = 0;
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BUG_ON((unsigned long)gdt->gdt & ~PAGE_MASK);
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make_lowmem_page_readonly(gdt->gdt);
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ctxt->gdt_frames[0] = virt_to_mfn(gdt->gdt);
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ctxt->gdt_ents = ARRAY_SIZE(gdt->gdt);
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ctxt->user_regs.cs = __KERNEL_CS;
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ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
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ctxt->kernel_ss = __KERNEL_DS;
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ctxt->kernel_sp = idle->thread.sp0;
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ctxt->event_callback_cs = __KERNEL_CS;
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ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback;
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ctxt->failsafe_callback_cs = __KERNEL_CS;
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ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback;
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per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
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ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
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if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
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BUG();
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kfree(ctxt);
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return 0;
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}
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int __cpuinit xen_cpu_up(unsigned int cpu)
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{
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struct task_struct *idle = idle_task(cpu);
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int rc;
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#if 0
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rc = cpu_up_check(cpu);
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if (rc)
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return rc;
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#endif
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init_gdt(cpu);
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per_cpu(current_task, cpu) = idle;
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irq_ctx_init(cpu);
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xen_setup_timer(cpu);
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/* make sure interrupts start blocked */
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per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
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rc = cpu_initialize_context(cpu, idle);
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if (rc)
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return rc;
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if (num_online_cpus() == 1)
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alternatives_smp_switch(1);
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rc = xen_smp_intr_init(cpu);
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if (rc)
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return rc;
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smp_store_cpu_info(cpu);
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set_cpu_sibling_map(cpu);
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/* This must be done before setting cpu_online_map */
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wmb();
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cpu_set(cpu, cpu_online_map);
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rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
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BUG_ON(rc);
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return 0;
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}
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void xen_smp_cpus_done(unsigned int max_cpus)
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{
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}
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static void stop_self(void *v)
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{
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int cpu = smp_processor_id();
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/* make sure we're not pinning something down */
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load_cr3(swapper_pg_dir);
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/* should set up a minimal gdt */
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HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
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BUG();
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}
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void xen_smp_send_stop(void)
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{
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smp_call_function(stop_self, NULL, 0, 0);
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}
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void xen_smp_send_reschedule(int cpu)
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{
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xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
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}
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static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector)
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{
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unsigned cpu;
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cpus_and(mask, mask, cpu_online_map);
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for_each_cpu_mask(cpu, mask)
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xen_send_IPI_one(cpu, vector);
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}
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static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
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{
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void (*func) (void *info) = call_data->func;
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void *info = call_data->info;
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int wait = call_data->wait;
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/*
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* Notify initiating CPU that I've grabbed the data and am
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* about to execute the function
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*/
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mb();
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atomic_inc(&call_data->started);
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/*
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* At this point the info structure may be out of scope unless wait==1
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*/
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irq_enter();
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(*func)(info);
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__get_cpu_var(irq_stat).irq_call_count++;
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irq_exit();
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if (wait) {
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mb(); /* commit everything before setting finished */
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atomic_inc(&call_data->finished);
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}
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return IRQ_HANDLED;
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}
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int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *),
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void *info, int wait)
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{
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struct call_data_struct data;
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int cpus, cpu;
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bool yield;
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/* Holding any lock stops cpus from going down. */
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spin_lock(&call_lock);
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cpu_clear(smp_processor_id(), mask);
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cpus = cpus_weight(mask);
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if (!cpus) {
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spin_unlock(&call_lock);
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return 0;
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}
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/* Can deadlock when called with interrupts disabled */
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WARN_ON(irqs_disabled());
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data.func = func;
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data.info = info;
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atomic_set(&data.started, 0);
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data.wait = wait;
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if (wait)
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atomic_set(&data.finished, 0);
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call_data = &data;
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mb(); /* write everything before IPI */
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/* Send a message to other CPUs and wait for them to respond */
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xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
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/* Make sure other vcpus get a chance to run if they need to. */
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yield = false;
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for_each_cpu_mask(cpu, mask)
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if (xen_vcpu_stolen(cpu))
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yield = true;
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if (yield)
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HYPERVISOR_sched_op(SCHEDOP_yield, 0);
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/* Wait for response */
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while (atomic_read(&data.started) != cpus ||
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(wait && atomic_read(&data.finished) != cpus))
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cpu_relax();
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spin_unlock(&call_lock);
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return 0;
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}
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