diff options
Diffstat (limited to 'kernel/arch/x86/xen/multicalls.h')
-rw-r--r-- | kernel/arch/x86/xen/multicalls.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/arch/x86/xen/multicalls.h b/kernel/arch/x86/xen/multicalls.h new file mode 100644 index 000000000..9c2e74f90 --- /dev/null +++ b/kernel/arch/x86/xen/multicalls.h @@ -0,0 +1,68 @@ +#ifndef _XEN_MULTICALLS_H +#define _XEN_MULTICALLS_H + +#include <trace/events/xen.h> + +#include "xen-ops.h" + +/* Multicalls */ +struct multicall_space +{ + struct multicall_entry *mc; + void *args; +}; + +/* Allocate room for a multicall and its args */ +struct multicall_space __xen_mc_entry(size_t args); + +DECLARE_PER_CPU(unsigned long, xen_mc_irq_flags); + +/* Call to start a batch of multiple __xen_mc_entry()s. Must be + paired with xen_mc_issue() */ +static inline void xen_mc_batch(void) +{ + unsigned long flags; + + /* need to disable interrupts until this entry is complete */ + local_irq_save(flags); + trace_xen_mc_batch(paravirt_get_lazy_mode()); + __this_cpu_write(xen_mc_irq_flags, flags); +} + +static inline struct multicall_space xen_mc_entry(size_t args) +{ + xen_mc_batch(); + return __xen_mc_entry(args); +} + +/* Flush all pending multicalls */ +void xen_mc_flush(void); + +/* Issue a multicall if we're not in a lazy mode */ +static inline void xen_mc_issue(unsigned mode) +{ + trace_xen_mc_issue(mode); + + if ((paravirt_get_lazy_mode() & mode) == 0) + xen_mc_flush(); + + /* restore flags saved in xen_mc_batch */ + local_irq_restore(this_cpu_read(xen_mc_irq_flags)); +} + +/* Set up a callback to be called when the current batch is flushed */ +void xen_mc_callback(void (*fn)(void *), void *data); + +/* + * Try to extend the arguments of the previous multicall command. The + * previous command's op must match. If it does, then it attempts to + * extend the argument space allocated to the multicall entry by + * arg_size bytes. + * + * The returned multicall_space will return with mc pointing to the + * command on success, or NULL on failure, and args pointing to the + * newly allocated space. + */ +struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size); + +#endif /* _XEN_MULTICALLS_H */ |