As requested by Linus add explicit __visible to the asmlinkage users. This marks all functions visible to assembler. Tree sweep for arch/x86/* Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
		
			
				
	
	
		
			136 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#include <linux/hardirq.h>
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#include <asm/x86_init.h>
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#include <xen/interface/xen.h>
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#include <xen/interface/sched.h>
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#include <xen/interface/vcpu.h>
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#include <xen/features.h>
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#include <xen/events.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/hypervisor.h>
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#include "xen-ops.h"
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/*
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 * Force a proper event-channel callback from Xen after clearing the
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 * callback mask. We do this in a very simple manner, by making a call
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 * down into Xen. The pending flag will be checked by Xen on return.
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 */
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void xen_force_evtchn_callback(void)
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{
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	(void)HYPERVISOR_xen_version(0, NULL);
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}
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asmlinkage __visible unsigned long xen_save_fl(void)
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{
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	struct vcpu_info *vcpu;
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	unsigned long flags;
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	vcpu = this_cpu_read(xen_vcpu);
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	/* flag has opposite sense of mask */
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	flags = !vcpu->evtchn_upcall_mask;
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	/* convert to IF type flag
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	   -0 -> 0x00000000
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	   -1 -> 0xffffffff
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	*/
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	return (-flags) & X86_EFLAGS_IF;
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl);
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__visible void xen_restore_fl(unsigned long flags)
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{
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	struct vcpu_info *vcpu;
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	/* convert from IF type flag */
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	flags = !(flags & X86_EFLAGS_IF);
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	/* See xen_irq_enable() for why preemption must be disabled. */
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	preempt_disable();
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	vcpu = this_cpu_read(xen_vcpu);
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	vcpu->evtchn_upcall_mask = flags;
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	if (flags == 0) {
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		barrier(); /* unmask then check (avoid races) */
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		if (unlikely(vcpu->evtchn_upcall_pending))
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			xen_force_evtchn_callback();
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		preempt_enable();
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	} else
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		preempt_enable_no_resched();
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_restore_fl);
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asmlinkage __visible void xen_irq_disable(void)
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{
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	/* There's a one instruction preempt window here.  We need to
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	   make sure we're don't switch CPUs between getting the vcpu
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	   pointer and updating the mask. */
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	preempt_disable();
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	this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1;
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	preempt_enable_no_resched();
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable);
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asmlinkage __visible void xen_irq_enable(void)
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{
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	struct vcpu_info *vcpu;
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	/*
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	 * We may be preempted as soon as vcpu->evtchn_upcall_mask is
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	 * cleared, so disable preemption to ensure we check for
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	 * events on the VCPU we are still running on.
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	 */
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	preempt_disable();
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	vcpu = this_cpu_read(xen_vcpu);
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	vcpu->evtchn_upcall_mask = 0;
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	/* Doesn't matter if we get preempted here, because any
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	   pending event will get dealt with anyway. */
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	barrier(); /* unmask then check (avoid races) */
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	if (unlikely(vcpu->evtchn_upcall_pending))
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		xen_force_evtchn_callback();
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	preempt_enable();
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable);
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static void xen_safe_halt(void)
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{
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	/* Blocking includes an implicit local_irq_enable(). */
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	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
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		BUG();
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}
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static void xen_halt(void)
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{
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	if (irqs_disabled())
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		HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
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	else
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		xen_safe_halt();
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}
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static const struct pv_irq_ops xen_irq_ops __initconst = {
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	.save_fl = PV_CALLEE_SAVE(xen_save_fl),
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	.restore_fl = PV_CALLEE_SAVE(xen_restore_fl),
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	.irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
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	.irq_enable = PV_CALLEE_SAVE(xen_irq_enable),
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	.safe_halt = xen_safe_halt,
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	.halt = xen_halt,
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#ifdef CONFIG_X86_64
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	.adjust_exception_frame = xen_adjust_exception_frame,
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#endif
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};
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void __init xen_init_irq_ops(void)
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{
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	/* For PVH we use default pv_irq_ops settings. */
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	if (!xen_feature(XENFEAT_hvm_callback_vector))
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		pv_irq_ops = xen_irq_ops;
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	x86_init.irqs.intr_init = xen_init_IRQ;
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}
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