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powerpc/64s: update cpu selection options

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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 <npiggin@gmail.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921014103.587954-2-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2022-09-21 11:41:03 +10:00 committed by Michael Ellerman
parent 58ec7f06b7
commit 7fd123e544
3 changed files with 21 additions and 6 deletions
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14
Documentation/powerpc/isa-versions.rst
View file

@ -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
========= ====================================================================
@ -26,6 +28,12 @@ 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
========= ====================================================================
@ -48,6 +56,8 @@ Power5++ No
Power5+ No
Power5 No
PPC970 Yes
Power4+ No
Power4 No
========== ==================
========== ====
@ -66,6 +76,8 @@ Power5++ No
Power5+ No
Power5 No
PPC970 No
Power4+ No
Power4 No
========== ====
========== ====================================
@ -84,4 +96,6 @@ Power5++ No
Power5+ No
Power5 No
PPC970 No
Power4+ No
Power4 No
========== ====================================

5
arch/powerpc/Makefile
View file

@ -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

8
arch/powerpc/platforms/Kconfig.cputype
View file

@ -126,7 +126,7 @@ 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
@ -145,8 +145,8 @@ 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
@ -235,7 +235,7 @@ 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