From: "Pali Rohár" <pali@kernel.org> To: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com>, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v1] powerpc/64: Set default CPU in Kconfig Date: Thu, 15 Dec 2022 21:42:02 +0100 [thread overview] Message-ID: <20221215204202.mbw2ij4ou7t2ttpv@pali> (raw) In-Reply-To: <3fd60c2d8a28668a42b766b18362a526ef47e757.1670420281.git.christophe.leroy@csgroup.eu> Hello! On Wednesday 07 December 2022 14:38:40 Christophe Leroy wrote: > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile ... > @@ -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 ... > @@ -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 Now I'm looking at this change again... and should not E5500_CPU rather enforce -mcpu=e5500 flag? I know that your patch moves e500mc64 flag from the Makefile to Kconfig, but maybe it could be changed in some other followup patch... Anyway, do you know what is e500mc64 core? I was trying to find some information about it, but it looks like some unreleased freescale core which predates e5500 core. ISA (without extensions like altivec) seems to be same for e500mc64, e5500 and e6500 cores and difference is only pipeline definitions in gcc config files. So if my understanding is correct then kernel binary compiled with any of these -mcpu= flag should work on any of those cores. Just for mismatches core binary will not be optimized for speed. > + 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 >
WARNING: multiple messages have this Message-ID (diff)
From: "Pali Rohár" <pali@kernel.org> To: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com> Subject: Re: [PATCH v1] powerpc/64: Set default CPU in Kconfig Date: Thu, 15 Dec 2022 21:42:02 +0100 [thread overview] Message-ID: <20221215204202.mbw2ij4ou7t2ttpv@pali> (raw) In-Reply-To: <3fd60c2d8a28668a42b766b18362a526ef47e757.1670420281.git.christophe.leroy@csgroup.eu> Hello! On Wednesday 07 December 2022 14:38:40 Christophe Leroy wrote: > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile ... > @@ -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 ... > @@ -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 Now I'm looking at this change again... and should not E5500_CPU rather enforce -mcpu=e5500 flag? I know that your patch moves e500mc64 flag from the Makefile to Kconfig, but maybe it could be changed in some other followup patch... Anyway, do you know what is e500mc64 core? I was trying to find some information about it, but it looks like some unreleased freescale core which predates e5500 core. ISA (without extensions like altivec) seems to be same for e500mc64, e5500 and e6500 cores and difference is only pipeline definitions in gcc config files. So if my understanding is correct then kernel binary compiled with any of these -mcpu= flag should work on any of those cores. Just for mismatches core binary will not be optimized for speed. > + 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 >
next prev parent reply other threads:[~2022-12-15 20:42 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-12-07 13:38 [PATCH v1] powerpc/64: Set default CPU in Kconfig Christophe Leroy 2022-12-07 13:38 ` Christophe Leroy 2022-12-08 19:13 ` Pali Rohár 2022-12-08 19:13 ` Pali Rohár 2022-12-15 20:42 ` Pali Rohár [this message] 2022-12-15 20:42 ` Pali Rohár 2022-12-16 19:15 ` Segher Boessenkool 2022-12-16 19:15 ` Segher Boessenkool 2022-12-16 22:23 ` Pali Rohár 2022-12-16 22:23 ` Pali Rohár 2022-12-16 23:02 ` Segher Boessenkool 2022-12-16 23:02 ` Segher Boessenkool
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