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

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