This adds a mechanism to register a callback function to be called once a batch of hypercalls has been issued. This is typically used to unlock things which must remain locked until the hypercall has taken place. [ Stable folks: pre-req for 2.6.23 bugfix "xen: deal with stale cr3 values when unpinning pagetables" ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Stable Kernel <stable@kernel.org>
		
			
				
	
	
		
			48 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			48 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _XEN_MULTICALLS_H
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#define _XEN_MULTICALLS_H
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#include "xen-ops.h"
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/* Multicalls */
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struct multicall_space
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{
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	struct multicall_entry *mc;
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	void *args;
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};
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/* Allocate room for a multicall and its args */
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struct multicall_space __xen_mc_entry(size_t args);
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DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags);
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/* Call to start a batch of multiple __xen_mc_entry()s.  Must be
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   paired with xen_mc_issue() */
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static inline void xen_mc_batch(void)
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{
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	/* need to disable interrupts until this entry is complete */
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	local_irq_save(__get_cpu_var(xen_mc_irq_flags));
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}
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static inline struct multicall_space xen_mc_entry(size_t args)
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{
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	xen_mc_batch();
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	return __xen_mc_entry(args);
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}
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/* Flush all pending multicalls */
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void xen_mc_flush(void);
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/* Issue a multicall if we're not in a lazy mode */
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static inline void xen_mc_issue(unsigned mode)
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{
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	if ((paravirt_get_lazy_mode() & mode) == 0)
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		xen_mc_flush();
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	/* restore flags saved in xen_mc_batch */
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	local_irq_restore(x86_read_percpu(xen_mc_irq_flags));
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}
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/* Set up a callback to be called when the current batch is flushed */
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void xen_mc_callback(void (*fn)(void *), void *data);
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#endif /* _XEN_MULTICALLS_H */
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