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
CC: Rusty Russell
CC: Christoph Hellwig
CC: Paul Mackerras
CC: Adrian Bunk
CC: Andi Kleen
CC: Alexey Dobriyan
CC: mingo@elte.hu
CC: akpm@osdl.org
---
arch/powerpc/Kconfig | 1
include/asm-powerpc/immediate.h | 55 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)

Index: linux-2.6-lttng.mm/include/asm-powerpc/immediate.h
================================================== =================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng.mm/include/asm-powerpc/immediate.h 2008-04-09 10:55:31.000000000 -0400
@@ -0,0 +1,55 @@
+#ifndef _ASM_POWERPC_IMMEDIATE_H
+#define _ASM_POWERPC_IMMEDIATE_H
+
+/*
+ * Immediate values. PowerPC architecture optimizations.
+ *
+ * (C) Copyright 2006 Mathieu Desnoyers
+ *
+ * This file is released under the GPLv2.
+ * See the file COPYING for more details.
+ */
+
+#include
+
+/**
+ * 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.mm/arch/powerpc/Kconfig
================================================== =================
--- linux-2.6-lttng.mm.orig/arch/powerpc/Kconfig 2008-04-09 10:26:07.000000000 -0400
+++ linux-2.6-lttng.mm/arch/powerpc/Kconfig 2008-04-09 10:55:48.000000000 -0400
@@ -92,6 +92,7 @@ config PPC
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_LMB
+ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/