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 */
10 struct multicall_space
11 {
12 	struct multicall_entry *mc;
13 	void *args;
14 };
15 
16 /* Allocate room for a multicall and its args */
17 struct multicall_space __xen_mc_entry(size_t args);
18 
19 DECLARE_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() */
xen_mc_batch(void)23 static 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 
xen_mc_entry(size_t args)33 static 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 */
40 void xen_mc_flush(void);
41 
42 /* Issue a multicall if we're not in a lazy mode */
xen_mc_issue(unsigned mode)43 static 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 */
55 void 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  */
67 struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
68 
69 #endif /* _XEN_MULTICALLS_H */
70