xref: /openbmc/linux/arch/x86/xen/multicalls.h (revision 9ac8d3fb)
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 	/* need to disable interrupts until this entry is complete */
23 	local_irq_save(__get_cpu_var(xen_mc_irq_flags));
24 }
25 
26 static inline struct multicall_space xen_mc_entry(size_t args)
27 {
28 	xen_mc_batch();
29 	return __xen_mc_entry(args);
30 }
31 
32 /* Flush all pending multicalls */
33 void xen_mc_flush(void);
34 
35 /* Issue a multicall if we're not in a lazy mode */
36 static inline void xen_mc_issue(unsigned mode)
37 {
38 	if ((paravirt_get_lazy_mode() & mode) == 0)
39 		xen_mc_flush();
40 
41 	/* restore flags saved in xen_mc_batch */
42 	local_irq_restore(x86_read_percpu(xen_mc_irq_flags));
43 }
44 
45 /* Set up a callback to be called when the current batch is flushed */
46 void xen_mc_callback(void (*fn)(void *), void *data);
47 
48 /*
49  * Try to extend the arguments of the previous multicall command.  The
50  * previous command's op must match.  If it does, then it attempts to
51  * extend the argument space allocated to the multicall entry by
52  * arg_size bytes.
53  *
54  * The returned multicall_space will return with mc pointing to the
55  * command on success, or NULL on failure, and args pointing to the
56  * newly allocated space.
57  */
58 struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
59 
60 #endif /* _XEN_MULTICALLS_H */
61