xref: /OK3568_Linux_fs/kernel/arch/x86/xen/multicalls.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _XEN_MULTICALLS_H
3*4882a593Smuzhiyun #define _XEN_MULTICALLS_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <trace/events/xen.h>
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include "xen-ops.h"
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun /* Multicalls */
10*4882a593Smuzhiyun struct multicall_space
11*4882a593Smuzhiyun {
12*4882a593Smuzhiyun 	struct multicall_entry *mc;
13*4882a593Smuzhiyun 	void *args;
14*4882a593Smuzhiyun };
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun /* Allocate room for a multicall and its args */
17*4882a593Smuzhiyun struct multicall_space __xen_mc_entry(size_t args);
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags);
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun /* Call to start a batch of multiple __xen_mc_entry()s.  Must be
22*4882a593Smuzhiyun    paired with xen_mc_issue() */
xen_mc_batch(void)23*4882a593Smuzhiyun static inline void xen_mc_batch(void)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun 	unsigned long flags;
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	/* need to disable interrupts until this entry is complete */
28*4882a593Smuzhiyun 	local_irq_save(flags);
29*4882a593Smuzhiyun 	trace_xen_mc_batch(paravirt_get_lazy_mode());
30*4882a593Smuzhiyun 	__this_cpu_write(xen_mc_irq_flags, flags);
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun 
xen_mc_entry(size_t args)33*4882a593Smuzhiyun static inline struct multicall_space xen_mc_entry(size_t args)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun 	xen_mc_batch();
36*4882a593Smuzhiyun 	return __xen_mc_entry(args);
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun /* Flush all pending multicalls */
40*4882a593Smuzhiyun void xen_mc_flush(void);
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun /* Issue a multicall if we're not in a lazy mode */
xen_mc_issue(unsigned mode)43*4882a593Smuzhiyun static inline void xen_mc_issue(unsigned mode)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun 	trace_xen_mc_issue(mode);
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun 	if ((paravirt_get_lazy_mode() & mode) == 0)
48*4882a593Smuzhiyun 		xen_mc_flush();
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	/* restore flags saved in xen_mc_batch */
51*4882a593Smuzhiyun 	local_irq_restore(this_cpu_read(xen_mc_irq_flags));
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun 
54*4882a593Smuzhiyun /* Set up a callback to be called when the current batch is flushed */
55*4882a593Smuzhiyun void xen_mc_callback(void (*fn)(void *), void *data);
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun /*
58*4882a593Smuzhiyun  * Try to extend the arguments of the previous multicall command.  The
59*4882a593Smuzhiyun  * previous command's op must match.  If it does, then it attempts to
60*4882a593Smuzhiyun  * extend the argument space allocated to the multicall entry by
61*4882a593Smuzhiyun  * arg_size bytes.
62*4882a593Smuzhiyun  *
63*4882a593Smuzhiyun  * The returned multicall_space will return with mc pointing to the
64*4882a593Smuzhiyun  * command on success, or NULL on failure, and args pointing to the
65*4882a593Smuzhiyun  * newly allocated space.
66*4882a593Smuzhiyun  */
67*4882a593Smuzhiyun struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun #endif /* _XEN_MULTICALLS_H */
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