[1/5] add tune options to Kconfig.cputypes

[1/5] add tune options to Kconfig.cputypes

[Marvin]

This patch adds tuning options similar to ppc32. In addition one can choose to 
compile exclusive for the selected (and higher) cpus.

Subject: [PATCH] add tune options to Kconfig.cputypes

---
 arch/powerpc/platforms/Kconfig.cputype |   79 ++++++++++++++++++++++++-------
 1 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/platforms/Kconfig.cputype 
b/arch/powerpc/platforms/Kconfig.cputype
index 5bc4b61..88e6ce2 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -54,35 +54,78 @@ config E200
 
 endchoice
 
-config POWER4_ONLY
-	bool "Optimize for POWER4"
+choice
+	prompt "Processor Type"
 	depends on PPC64
+	default TUNE_POWER4
+	help
+	  There are serveral families of 64 bit PowerPC chips supported.
+	  These include the RS64, Power3 to Power6 series, 970, and 
+	  Cell BE based CPUs made be IBM.
+
+	  If unsure, select Power4.
+
+config TUNE_RS64
+	bool "RS64"
+
+config TUNE_POWER3
+	bool "Power3"
+
+config TUNE_POWER4
+	bool "Power4"
+
+config TUNE_970
+	bool "970/G5"
+
+config TUNE_POWER5
+	bool "Power5"
+
+config TUNE_POWER6
+	bool "Power6"
+
+config TUNE_CELL
+	bool "Cell Broadband Engine"
+	help
+	  Cause the compiler to optimize for the PPE of the Cell Broadband
+	  Engine. This will make the code run considerably faster on Cell
+	  but somewhat slower on other machines. If the resulting kernel is
+	  built to run only on Cell BE machines, select also OPT_EXCLUSIVE.
+
+endchoice
+
+config OPT_EXCLUSIVE
+	bool "Optimize to run exclusive on selected CPU"
 	default n
-	---help---
-	  Cause the compiler to optimize for POWER4/POWER5/PPC970 processors.
-	  The resulting binary will not work on POWER3 or RS64 processors
-	  when compiled with binutils 2.15 or later.
+	help
+	  Cause the compiler to optimize to run exclusive on the selected
+	  CPU. The resulting binary will probably not work on older CPUs, 
+	  but should work on newer ones.
+	  
+	  See the following chart for supported PPC64 CPU generations.
+	  
+	  older <------------------------------> newer
+
+	  RS64 -> POWER3 -> POWER4 -> POWER5 -> POWER6
+	                    970/G5
+	                    CELL BE
+	                    PA6T
+	  
+	  If the compiler/binutils combination does not support the exclusive
+	  optimization, it will try to tune only or fail.
+	  
+	  If you are unsure, select no.
 
 config POWER3
-	bool
 	depends on PPC64
-	default y if !POWER4_ONLY
+	def_bool y if !POWER4_ONLY
 
 config POWER4
 	depends on PPC64
 	def_bool y
 
-config TUNE_CELL
-	bool "Optimize for Cell Broadband Engine"
+config POWER4_ONLY
 	depends on PPC64
-	help
-	  Cause the compiler to optimize for the PPE of the Cell Broadband
-	  Engine. This will make the code run considerably faster on Cell
-	  but somewhat slower on other machines. This option only changes
-	  the scheduling of instructions, not the selection of instructions
-	  itself, so the resulting kernel will keep running on all other
-	  machines. When building a kernel that is supposed to run only
-	  on Cell, you should also select the POWER4_ONLY option.
+	def_bool y if TUNE_POWER4 && OPT_EXCLUSIVE
 
 config 6xx
 	bool
-- 
1.5.6.2

Re: [1/5] add tune options to Kconfig.cputypes

[Olof Johansson]

Hi,

On Sun, Jul 20, 2008 at 07:48:24PM +0200, Marvin wrote:

> +	  RS64 -> POWER3 -> POWER4 -> POWER5 -> POWER6
> +	                    970/G5
> +	                    CELL BE
> +	                    PA6T
> +	  
> +	  If the compiler/binutils combination does not support the exclusive
> +	  optimization, it will try to tune only or fail.

PA6T implements 2.04 and a few pieces of 2.05, so it sits between
POWER5+ and POWER6 feature-wise.


-Olof