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-rw-r--r--arch/x86/xen/multicalls.h69
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/x86/xen/multicalls.h b/arch/x86/xen/multicalls.h
new file mode 100644
index 000000000..1c51b2c87
--- /dev/null
+++ b/arch/x86/xen/multicalls.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 */