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() */ 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 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 */ 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