LXR linux/arch/x86/xen/multicalls.h

   1#ifndef _XEN_MULTICALLS_H
   2#define _XEN_MULTICALLS_H
   3
   4#include <trace/events/xen.h>
   5
   6#include "xen-ops.h"
   7
   8/* Multicalls */
   9struct multicall_space
  10{
  11        struct multicall_entry *mc;
  12        void *args;
  13};
  14
  15/* Allocate room for a multicall and its args */
  16struct multicall_space __xen_mc_entry(size_t args);
  17
  18DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags);
  19
  20/* Call to start a batch of multiple __xen_mc_entry()s.  Must be
  21   paired with xen_mc_issue() */
  22static inline void xen_mc_batch(void)
  23{
  24        unsigned long flags;
  25
  26        /* need to disable interrupts until this entry is complete */
  27        local_irq_save(flags);
  28        trace_xen_mc_batch(paravirt_get_lazy_mode());
  29        __this_cpu_write(xen_mc_irq_flags, flags);
  30}
  31
  32static inline struct multicall_space xen_mc_entry(size_t args)
  33{
  34        xen_mc_batch();
  35        return __xen_mc_entry(args);
  36}
  37
  38/* Flush all pending multicalls */
  39void xen_mc_flush(void);
  40
  41/* Issue a multicall if we're not in a lazy mode */
  42static inline void xen_mc_issue(unsigned mode)
  43{
  44        trace_xen_mc_issue(mode);
  45
  46        if ((paravirt_get_lazy_mode() & mode) == 0)
  47                xen_mc_flush();
  48
  49        /* restore flags saved in xen_mc_batch */
  50        local_irq_restore(this_cpu_read(xen_mc_irq_flags));
  51}
  52
  53/* Set up a callback to be called when the current batch is flushed */
  54void xen_mc_callback(void (*fn)(void *), void *data);
  55
  56/*
  57 * Try to extend the arguments of the previous multicall command.  The
  58 * previous command's op must match.  If it does, then it attempts to
  59 * extend the argument space allocated to the multicall entry by
  60 * arg_size bytes.
  61 *
  62 * The returned multicall_space will return with mc pointing to the
  63 * command on success, or NULL on failure, and args pointing to the
  64 * newly allocated space.
  65 */
  66struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
  67
  68#endif /* _XEN_MULTICALLS_H */
  69