Commit 7fd123e5 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s: update cpu selection options 



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: default avatarNicholas Piggin <npiggin@gmail.com>
Reviewed-by: default avatarSegher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921014103.587954-2-npiggin@gmail.com
parent 58ec7f06

Documentation/powerpc/isa-versions.rst

+14 −0
Original line number Diff line number Diff line
@@ -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

========== ====================================

arch/powerpc/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -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

arch/powerpc/platforms/Kconfig.cputype

+4 −4
Original line number Diff line number Diff line
@@ -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