[patch 04/10] Linux Kernel Markers - PowerPC optimized version

Mathieu Desnoyers
2007-05-10T02:53:36Z

[-- Attachment #1: linux-kernel-markers-powerpc-optimization.patch --]
[-- Type: text/plain, Size: 4968 bytes --]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

arch/powerpc/kernel/Makefile | 1
arch/powerpc/kernel/marker.c | 25 ++++++++++++
include/asm-powerpc/marker.h | 85 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 111 insertions(+)

Index: linux-2.6-lttng/arch/powerpc/kernel/Makefile
===================================================================
--- linux-2.6-lttng.orig/arch/powerpc/kernel/Makefile 2007-05-09 18:14:51.000000000 -0400
+++ linux-2.6-lttng/arch/powerpc/kernel/Makefile 2007-05-09 18:16:00.000000000 -0400
@@ -96,3 +96,4 @@

extra-$(CONFIG_PPC_FPU) += fpu.o
extra-$(CONFIG_PPC64) += entry_64.o
+obj-$(CONFIG_MARKERS_ENABLE_OPTIMIZATION) += marker.o
Index: linux-2.6-lttng/arch/powerpc/kernel/marker.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/arch/powerpc/kernel/marker.c 2007-05-09 18:16:00.000000000 -0400
@@ -0,0 +1,25 @@
+/* marker.c
+ *
+ * Powerpc optimized marker enabling/disabling.
+ *
+ * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ */
+
+#include <linux/module.h>
+#include <linux/marker.h>
+#include <linux/string.h>
+#include <asm/cacheflush.h>
+
+int marker_optimized_set_enable(void *address, char enable)
+{
+ char newi[MARK_OPTIMIZED_ENABLE_IMMEDIATE_OFFSET+1];
+ int size = MARK_OPTIMIZED_ENABLE_IMMEDIATE_OFFSET
+ + sizeof(MARK_OPTIMIZED_ENABLE_TYPE);
+
+ memcpy(newi, address, size);
+ MARK_OPTIMIZED_ENABLE(&newi[0]) = enable;
+ memcpy(address, newi, size);
+ flush_icache_range((unsigned long)address, size);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(marker_optimized_set_enable);
Index: linux-2.6-lttng/include/asm-powerpc/marker.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/include/asm-powerpc/marker.h 2007-05-09 18:16:00.000000000 -0400
@@ -0,0 +1,85 @@
+#ifndef _ASM_POWERPC_MARKER_H
+#define _ASM_POWERPC_MARKER_H
+
+/*
+ * marker.h
+ *
+ * Code markup for dynamic and static tracing. PowerPC architecture
+ * optimisations.
+ *
+ * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * This file is released under the GPLv2.
+ * See the file COPYING for more details.
+ */
+
+#include <asm/asm-compat.h>
+
+#ifdef CONFIG_MARKERS
+
+#define MF_DEFAULT (MF_OPTIMIZED | MF_LOCKDEP | MF_PRINTK)
+
+/* Optimized version of the markers */
+#define trace_mark_optimized(flags, name, format, args...) \
+ do { \
+ static const char __mstrtab_name_##name[] \
+ __attribute__((section("__markers_strings"))) \
+ = #name; \
+ static const char __mstrtab_format_##name[] \
+ __attribute__((section("__markers_strings"))) \
+ = format; \
+ static const char __mstrtab_args_##name[] \
+ __attribute__((section("__markers_strings"))) \
+ = #args; \
+ static struct __mark_marker_data __mark_data_##name \
+ __attribute__((section("__markers_data"))) = \
+ { __mstrtab_name_##name, __mstrtab_format_##name, \
+ __mstrtab_args_##name, \
+ (flags) | MF_OPTIMIZED, __mark_empty_function, NULL }; \
+ char condition; \
+ asm volatile( ".section __markers, \"a\", @progbits;\n\t" \
+ PPC_LONG "%1, 0f;\n\t" \
+ ".previous;\n\t" \
+ ".align 4\n\t" \
+ "0:\n\t" \
+ "li %0,0;\n\t" \
+ : "=r" (condition) \
+ : "i" (&__mark_data_##name)); \
+ __mark_check_format(format, ## args); \
+ if (unlikely(condition)) { \
+ preempt_disable(); \
+ (*__mark_data_##name.call)(&__mark_data_##name, \
+ format, ## args); \
+ preempt_enable(); \
+ } \
+ } while (0)
+
+/* Marker macro selecting the generic or optimized version of marker, depending
+ * on the flags specified. */
+#define _trace_mark(flags, format, args...) \
+do { \
+ if ((flags) & MF_OPTIMIZED) \
+ trace_mark_optimized(flags, format, ## args); \
+ else \
+ trace_mark_generic(flags, format, ## args); \
+} while (0)
+
+/* Marker with default behavior */
+#define trace_mark(format, args...) _trace_mark(MF_DEFAULT, format, ## args)
+
+/* Architecture dependant marker information, used internally for marker
+ * activation. */
+
+/* Offset of the immediate value from the start of the addi instruction (result
+ * of the li mnemonic), in bytes. */
+#define MARK_OPTIMIZED_ENABLE_IMMEDIATE_OFFSET 2
+#define MARK_OPTIMIZED_ENABLE_TYPE short
+/* Dereference enable as lvalue from a pointer to its instruction */
+#define MARK_OPTIMIZED_ENABLE(a) \
+ *(MARK_OPTIMIZED_ENABLE_TYPE*) \
+ ((char*)a+MARK_OPTIMIZED_ENABLE_IMMEDIATE_OFFSET)
+
+extern int marker_optimized_set_enable(void *address, char enable);
+
+#endif
+#endif //_ASM_POWERPC_MARKER_H

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68