arch/x86/xen/multicalls.h

   1 #ifndef _XEN_MULTICALLS_H
   2 #define _XEN_MULTICALLS_H
   3
   4 #include "xen-ops.h"
   5
   6 /* Multicalls */
   7 struct multicall_space
   8 {
   9         struct multicall_entry *mc;
  10         void *args;
  11 };
  12
  13 /* Allocate room for a multicall and its args */
  14 struct multicall_space __xen_mc_entry(size_t args);
  15
  16 DECLARE_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() */
  20 static 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
  28 static 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 */
  35 void xen_mc_flush(void);
  36
  37 /* Issue a multicall if we're not in a lazy mode */
  38 static 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 */
  48 void 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  */
  60 struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
  61
  62 #endif /* _XEN_MULTICALLS_H */