PowerPC optimization of the immediate values which uses a li instruction,
patched with an immediate value.
Changelog:
- Put imv_set and _imv_set in the architecture independent header.
- Pack the __imv section. Use smallest types required for size (char).
- Remove architecture specific update code : now handled by architecture
agnostic code.
- Use imv_* instead of immediate_*.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Christoph Hellwig <hch@infradead.org>
CC: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/Kconfig | 1
include/asm-powerpc/immediate.h | 55 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)
Index: linux-2.6-lttng/include/asm-powerpc/immediate.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/include/asm-powerpc/immediate.h 2008-01-30 09:33:42.000000000 -0500
@@ -0,0 +1,55 @@
+#ifndef _ASM_POWERPC_IMMEDIATE_H
+#define _ASM_POWERPC_IMMEDIATE_H
+
+/*
+ * Immediate values. PowerPC architecture optimizations.
+ *
+ * (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>
+
+/**
+ * imv_read - read immediate variable
+ * @name: immediate value name
+ *
+ * Reads the value of @name.
+ * Optimized version of the immediate.
+ * Do not use in __init and __exit functions. Use _imv_read() instead.
+ */
+#define imv_read(name) \
+ ({ \
+ __typeof__(name##__imv) value; \
+ BUILD_BUG_ON(sizeof(value) > 8); \
+ switch (sizeof(value)) { \
+ case 1: \
+ asm(".section __imv,\"a\",@progbits\n\t" \
+ PPC_LONG "%c1, ((1f)-1)\n\t" \
+ ".byte 1\n\t" \
+ ".previous\n\t" \
+ "li %0,0\n\t" \
+ "1:\n\t" \
+ : "=r" (value) \
+ : "i" (&name##__imv)); \
+ break; \
+ case 2: \
+ asm(".section __imv,\"a\",@progbits\n\t" \
+ PPC_LONG "%c1, ((1f)-2)\n\t" \
+ ".byte 2\n\t" \
+ ".previous\n\t" \
+ "li %0,0\n\t" \
+ "1:\n\t" \
+ : "=r" (value) \
+ : "i" (&name##__imv)); \
+ break; \
+ case 4: \
+ case 8: value = name##__imv; \
+ break; \
+ }; \
+ value; \
+ })
+
+#endif /* _ASM_POWERPC_IMMEDIATE_H */
Index: linux-2.6-lttng/arch/powerpc/Kconfig
===================================================================
--- linux-2.6-lttng.orig/arch/powerpc/Kconfig 2008-01-30 09:14:21.000000000 -0500
+++ linux-2.6-lttng/arch/powerpc/Kconfig 2008-01-30 09:33:42.000000000 -0500
@@ -89,6 +89,7 @@ config PPC
default y
select HAVE_OPROFILE
select HAVE_KPROBES
+ select HAVE_IMMEDIATE
config EARLY_PRINTK
bool
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
--
