lkml.org 
[lkml]   [2022]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v1] powerpc/64: Set default CPU in Kconfig
    On Wednesday 07 December 2022 14:38:40 Christophe Leroy wrote:
    > Since 0069f3d14e7a ("powerpc/64e: Tie PPC_BOOK3E_64 to PPC_E500MC"),
    > the only possible BOOK3E/64 are E500, so no need of a default CPU
    > over the E5500.
    > When the user selects book3e, he must have a e500 compatible compiler,
    > and it won't work anymore with the default -mcpu=power64, see
    > commit d6b551b8f90c ("powerpc/64e: Fix build failure with GCC 12
    > (unrecognized opcode: `wrteei')")
    >
    > For book3s/64, replace GENERIC_CPU by POWERPC64_CPU to match the PPC32
    > POWERPC_CPU, and set a default mpcu value in Kconfig directly.
    >
    > When a user selects a particular CPU, he must ensure his compiler has
    > the requested capability. Therefore, remove hidden fallback, instead
    > offer user the possibility to say he wants to use toolchain default.
    >
    > Reported-by: Pali Rohár <pali@kernel.org>
    > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

    Tested-by: Pali Rohár <pali@kernel.org>

    $ make ARCH=powerpc CROSS_COMPILE=powerpc64-linux-gnu- corenet64_smp_defconfig
    ...
    # configuration written to .config

    $ grep CONFIG_TARGET_CPU .config
    CONFIG_TARGET_CPU_BOOL=y
    CONFIG_TARGET_CPU="e500mc64"

    Without this patch CONFIG_TARGET_CPU is not set but CONFIG_TARGET_CPU_BOOL is.

    > ---
    > arch/powerpc/Makefile | 22 +++++-----------------
    > arch/powerpc/platforms/Kconfig.cputype | 12 +++++++-----
    > 2 files changed, 12 insertions(+), 22 deletions(-)
    >
    > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
    > index dc4cbf0a5ca9..bf5f0a998273 100644
    > --- a/arch/powerpc/Makefile
    > +++ b/arch/powerpc/Makefile
    > @@ -146,19 +146,6 @@ CFLAGS-$(CONFIG_PPC32) += $(call cc-option, $(MULTIPLEWORD))
    >
    > CFLAGS-$(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
    > -else
    > -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
    > -
    > ifdef CONFIG_FUNCTION_TRACER
    > CC_FLAGS_FTRACE := -pg
    > ifdef CONFIG_MPROFILE_KERNEL
    > @@ -166,11 +153,12 @@ CC_FLAGS_FTRACE += -mprofile-kernel
    > endif
    > endif
    >
    > -CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU))
    > -AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU))
    > +CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU)
    > +AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU)
    >
    > -CFLAGS-$(CONFIG_E5500_CPU) += $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
    > -CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU))
    > +CFLAGS-$(CONFIG_POWERPC64_CPU) += $(call cc-option,-mtune=power10, \
    > + $(call cc-option,-mtune=power9, \
    > + $(call cc-option,-mtune=power8)))
    >
    > asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
    >
    > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
    > index 9563336e3348..31cea2eeb59e 100644
    > --- a/arch/powerpc/platforms/Kconfig.cputype
    > +++ b/arch/powerpc/platforms/Kconfig.cputype
    > @@ -118,19 +118,18 @@ endchoice
    >
    > choice
    > prompt "CPU selection"
    > - default GENERIC_CPU
    > help
    > This will create a kernel which is optimised for a particular CPU.
    > The resulting kernel may not run on other CPUs, so use this with care.
    >
    > If unsure, select Generic.
    >
    > -config GENERIC_CPU
    > +config POWERPC64_CPU
    > bool "Generic (POWER5 and PowerPC 970 and above)"
    > depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
    > select PPC_64S_HASH_MMU
    >
    > -config GENERIC_CPU
    > +config POWERPC64_CPU
    > bool "Generic (POWER8 and above)"
    > depends on PPC_BOOK3S_64 && CPU_LITTLE_ENDIAN
    > select ARCH_HAS_FAST_MULTIPLIER
    > @@ -233,13 +232,12 @@ config E500MC_CPU
    >
    > config TOOLCHAIN_DEFAULT_CPU
    > bool "Rely on the toolchain's implicit default CPU"
    > - depends on PPC32
    >
    > endchoice
    >
    > config TARGET_CPU_BOOL
    > bool
    > - default !GENERIC_CPU && !TOOLCHAIN_DEFAULT_CPU
    > + default !TOOLCHAIN_DEFAULT_CPU
    >
    > config TARGET_CPU
    > string
    > @@ -251,6 +249,10 @@ config TARGET_CPU
    > default "power8" if POWER8_CPU
    > default "power9" if POWER9_CPU
    > default "power10" if POWER10_CPU
    > + default "e500mc64" if E5500_CPU
    > + default "e6500" if E6500_CPU
    > + default "power4" if POWERPC64_CPU && !CPU_LITTLE_ENDIAN
    > + default "power8" if POWERPC64_CPU && CPU_LITTLE_ENDIAN
    > default "405" if 405_CPU
    > default "440" if 440_CPU
    > default "464" if 464_CPU
    > --
    > 2.38.1
    >

    \
     
     \ /
      Last update: 2022-12-08 20:14    [W:4.782 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site