powerpc: tracing: Add hypervisor call tracepoints
Add hcall_entry and hcall_exit tracepoints. This replaces the inline
assembly HCALL_STATS code and converts it to use the new tracepoints.
To keep the disabled case as quick as possible, we embed a status word
in the TOC so we can get at it with a single load. By doing so we
keep the overhead at a minimum. Time taken for a null hcall:
No tracepoint code: 135.79 cycles
Disabled tracepoints: 137.95 cycles
For reference, before this patch enabling HCALL_STATS resulted in a null
hcall of 201.44 cycles!
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h
index b558c31..9b01c0e 100644
--- a/arch/powerpc/include/asm/trace.h
+++ b/arch/powerpc/include/asm/trace.h
@@ -76,6 +76,51 @@
TP_printk("pt_regs=%p", __entry->regs)
);
+#ifdef CONFIG_PPC_PSERIES
+extern void hcall_tracepoint_regfunc(void);
+extern void hcall_tracepoint_unregfunc(void);
+
+TRACE_EVENT_FN(hcall_entry,
+
+ TP_PROTO(unsigned long opcode),
+
+ TP_ARGS(opcode),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, opcode)
+ ),
+
+ TP_fast_assign(
+ __entry->opcode = opcode;
+ ),
+
+ TP_printk("opcode=%lu", __entry->opcode),
+
+ hcall_tracepoint_regfunc, hcall_tracepoint_unregfunc
+);
+
+TRACE_EVENT_FN(hcall_exit,
+
+ TP_PROTO(unsigned long opcode, unsigned long retval),
+
+ TP_ARGS(opcode, retval),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, opcode)
+ __field(unsigned long, retval)
+ ),
+
+ TP_fast_assign(
+ __entry->opcode = opcode;
+ __entry->retval = retval;
+ ),
+
+ TP_printk("opcode=%lu retval=%lu", __entry->opcode, __entry->retval),
+
+ hcall_tracepoint_regfunc, hcall_tracepoint_unregfunc
+);
+#endif
+
#endif /* _TRACE_POWERPC_H */
#undef TRACE_INCLUDE_PATH