Re: [PATCH 2/2] powerpc/64s: update cpu selection options

2022-09-21 Thread Segher Boessenkool
On Wed, Sep 21, 2022 at 11:41:03AM +1000, Nicholas Piggin wrote:
> Update the 64s GENERIC_CPU option. POWER4 support has been dropped, so
> make that clear in the option name. The POWER5_CPU option is dropped
> because it's uncommon, and GENERIC_CPU covers it.
> 
> -mtune= before power8 is dropped because the minimum gcc version
> supports power8, and tuning is made consistent between big and little
> endian.
> 
> A 970 option is added for PowerPC 970 / G5 because they still have a
> user base, and -mtune=power8 does not generate good code for the 970.
> 
> This also updates the ISA versions document to add Power4/Power4+
> because I didn't realise Power4+ used 2.01.
> 
> Signed-off-by: Nicholas Piggin 

Reviewed-by: Segher Boessenkool 

Cheers,


Segher


[PATCH 2/2] powerpc/64s: update cpu selection options

2022-09-20 Thread Nicholas Piggin
Update the 64s GENERIC_CPU option. POWER4 support has been dropped, so
make that clear in the option name. The POWER5_CPU option is dropped
because it's uncommon, and GENERIC_CPU covers it.

-mtune= before power8 is dropped because the minimum gcc version
supports power8, and tuning is made consistent between big and little
endian.

A 970 option is added for PowerPC 970 / G5 because they still have a
user base, and -mtune=power8 does not generate good code for the 970.

This also updates the ISA versions document to add Power4/Power4+
because I didn't realise Power4+ used 2.01.

Signed-off-by: Nicholas Piggin 
---
The 970 option builds and boots a QEMU TCG 970 machine.

 Documentation/powerpc/isa-versions.rst | 14 ++
 arch/powerpc/Makefile  |  5 +++--
 arch/powerpc/platforms/Kconfig.cputype |  8 
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/Documentation/powerpc/isa-versions.rst 
b/Documentation/powerpc/isa-versions.rst
index dfcb1097dce4..a242b3821681 100644
--- a/Documentation/powerpc/isa-versions.rst
+++ b/Documentation/powerpc/isa-versions.rst
@@ -4,6 +4,8 @@ CPU to ISA Version Mapping
 
 Mapping of some CPU versions to relevant ISA versions.
 
+Note Power4 and Power4+ are not supported.
+
 = 
 CPU   Architecture version
 = 
@@ -24,6 +26,12 @@ PPC970- PowerPC User Instruction Set Architecture Book I 
v2.01
   - PowerPC Virtual Environment Architecture Book II v2.01
   - PowerPC Operating Environment Architecture Book III v2.01
   - Plus Altivec/VMX ~= 2.03
+Power4+   - PowerPC User Instruction Set Architecture Book I v2.01
+  - PowerPC Virtual Environment Architecture Book II v2.01
+  - PowerPC Operating Environment Architecture Book III v2.01
+Power4- PowerPC User Instruction Set Architecture Book I v2.00
+  - PowerPC Virtual Environment Architecture Book II v2.00
+  - PowerPC Operating Environment Architecture Book III v2.00
 = 
 
 
@@ -44,6 +52,8 @@ Power5++   No
 Power5+No
 Power5 No
 PPC970 Yes
+Power4+No
+Power4 No
 == ==
 
 == 
@@ -60,6 +70,8 @@ Power5++   No
 Power5+No
 Power5 No
 PPC970 No
+Power4+No
+Power4 No
 == 
 
 == 
@@ -76,4 +88,6 @@ Power5++   No
 Power5+No
 Power5 No
 PPC970 No
+Power4+No
+Power4 No
 == 
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 140a5e6471fe..8a3d69b02672 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -149,11 +149,12 @@ CFLAGS-$(CONFIG_PPC32)+= $(call 
cc-option,-mno-readonly-in-sdata)
 ifdef CONFIG_PPC_BOOK3S_64
 ifdef CONFIG_CPU_LITTLE_ENDIAN
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8
-CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power9,-mtune=power8)
 else
-CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,$(call 
cc-option,-mtune=power5))
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power4
 endif
+CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power10,   \
+ $(call cc-option,-mtune=power9,   \
+ $(call cc-option,-mtune=power8)))
 else ifdef CONFIG_PPC_BOOK3E_64
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
 endif
diff --git a/arch/powerpc/platforms/Kconfig.cputype 
b/arch/powerpc/platforms/Kconfig.cputype
index 5185d942b455..4017be72e46f 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -125,7 +125,7 @@ choice
  If unsure, select Generic.
 
 config GENERIC_CPU
-   bool "Generic (POWER4 and above)"
+   bool "Generic (POWER5 and PowerPC 970 and above)"
depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
select PPC_64S_HASH_MMU
 
@@ -144,8 +144,8 @@ config CELL_CPU
depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
select PPC_64S_HASH_MMU
 
-config POWER5_CPU
-   bool "POWER5"
+config PPC_970_CPU
+   bool "PowerPC 970 (including PowerPC G5)"
depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
select PPC_64S_HASH_MMU
 
@@ -234,7 +234,7 @@ config TARGET_CPU
string
depends on TARGET_CPU_BOOL
default "cell" if CELL_CPU
-   default "power5" if POWER5_CPU
+   default "970" if PPC_970_CPU
default "power6" if POWER6_CPU
default "power7" if POWER7_CPU
default "power8" if POWER8_CPU
-- 
2.37.2