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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _XEN_MULTICALLS_H
   3#define _XEN_MULTICALLS_H
   4
   5#include <trace/events/xen.h>
   6
   7#include "xen-ops.h"
   8
   9/* Multicalls */
  10struct multicall_space
  11{
  12        struct multicall_entry *mc;
  13        void *args;
  14};
  15
  16/* Allocate room for a multicall and its args */
  17struct multicall_space __xen_mc_entry(size_t args);
  18
  19DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags);
  20
  21/* Call to start a batch of multiple __xen_mc_entry()s.  Must be
  22   paired with xen_mc_issue() */
  23static inline void xen_mc_batch(void)
  24{
  25        unsigned long flags;
  26
  27        /* need to disable interrupts until this entry is complete */
  28        local_irq_save(flags);
  29        trace_xen_mc_batch(paravirt_get_lazy_mode());
  30        __this_cpu_write(xen_mc_irq_flags, flags);
  31}
  32
  33static inline struct multicall_space xen_mc_entry(size_t args)
  34{
  35        xen_mc_batch();
  36        return __xen_mc_entry(args);
  37}
  38
  39/* Flush all pending multicalls */
  40void xen_mc_flush(void);
  41
  42/* Issue a multicall if we're not in a lazy mode */
  43static inline void xen_mc_issue(unsigned mode)
  44{
  45        trace_xen_mc_issue(mode);
  46
  47        if ((paravirt_get_lazy_mode() & mode) == 0)
  48                xen_mc_flush();
  49
  50        /* restore flags saved in xen_mc_batch */
  51        local_irq_restore(this_cpu_read(xen_mc_irq_flags));
  52}
  53
  54/* Set up a callback to be called when the current batch is flushed */
  55void xen_mc_callback(void (*fn)(void *), void *data);
  56
  57/*
  58 * Try to extend the arguments of the previous multicall command.  The
  59 * previous command's op must match.  If it does, then it attempts to
  60 * extend the argument space allocated to the multicall entry by
  61 * arg_size bytes.
  62 *
  63 * The returned multicall_space will return with mc pointing to the
  64 * command on success, or NULL on failure, and args pointing to the
  65 * newly allocated space.
  66 */
  67struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
  68
  69#endif /* _XEN_MULTICALLS_H */
  70