From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com> Cc: "Christophe Leroy" <christophe.leroy@csgroup.eu>, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Pali Rohár" <pali@kernel.org>, "Arnd Bergmann" <arnd@arndb.de>, "Segher Boessenkool" <segher@kernel.crashing.org> Subject: [PATCH v1 2/5] powerpc/32: Don't always pass -mcpu=powerpc to the compiler Date: Mon, 11 Jul 2022 16:19:30 +0200 [thread overview] Message-ID: <d4df724691351531bf46d685d654689e5dfa0d74.1657549153.git.christophe.leroy@csgroup.eu> (raw) In-Reply-To: <8abab4888da69ff78b73a56f64d9678a7bf684e9.1657549153.git.christophe.leroy@csgroup.eu> Since commit 4bf4f42a2feb ("powerpc/kbuild: Set default generic machine type for 32-bit compile"), when building a 32 bits kernel with a bi-arch version of GCC, or when building a book3s/32 kernel, the option -mcpu=powerpc is passed to GCC at all time, relying on it being eventually overriden by a subsequent -mcpu=xxxx. But when building the same kernel with a 32 bits only version of GCC, that is not done, relying on gcc being built with the expected default CPU. This logic has two problems. First, it is a bit fragile to rely on whether the GCC version is bi-arch or not, because today we can have bi-arch versions of GCC configured with a 32 bits default. Second, there are some versions of GCC which don't support -mcpu=powerpc, for instance for e500 SPE-only versions. So, stop relying on this approximative logic and allow the user to decide whether he/she wants to use the toolchain's default CPU or if he/she wants to set one, and allow only possible CPUs based on the selected target. Reported-by: Pali Rohár <pali@kernel.org> Tested-by: Pali Rohár <pali@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/Makefile | 26 +------------------------- arch/powerpc/platforms/Kconfig.cputype | 21 ++++++++++++++++++--- 2 files changed, 19 insertions(+), 28 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index a0cd70712061..d54e1fe03551 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -15,23 +15,6 @@ HAS_BIARCH := $(call cc-option-yn, -m32) # Set default 32 bits cross compilers for vdso and boot wrapper CROSS32_COMPILE ?= -ifeq ($(HAS_BIARCH),y) -ifeq ($(CROSS32_COMPILE),) -ifdef CONFIG_PPC32 -# These options will be overridden by any -mcpu option that the CPU -# or platform code sets later on the command line, but they are needed -# to set a sane 32-bit cpu target for the 64-bit cross compiler which -# may default to the wrong ISA. -KBUILD_CFLAGS += -mcpu=powerpc -KBUILD_AFLAGS += -mcpu=powerpc -endif -endif -endif - -ifdef CONFIG_PPC_BOOK3S_32 -KBUILD_CFLAGS += -mcpu=powerpc -endif - # If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use # ppc64_defconfig because we have nothing better to go on. uname := $(shell uname -m) @@ -183,6 +166,7 @@ endif endif CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) +AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) # Altivec option not allowed with e500mc64 in GCC. ifdef CONFIG_ALTIVEC @@ -193,14 +177,6 @@ endif CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU) CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU)) -ifdef CONFIG_PPC32 -ifdef CONFIG_PPC_E500MC -CFLAGS-y += $(call cc-option,-mcpu=e500mc,-mcpu=powerpc) -else -CFLAGS-$(CONFIG_E500) += $(call cc-option,-mcpu=8540 -msoft-float,-mcpu=powerpc) -endif -endif - asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1) KBUILD_CPPFLAGS += -I $(srctree)/arch/$(ARCH) $(asinstr) diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 9805a2c717b9..bfea5d8452f8 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -135,9 +135,9 @@ config GENERIC_CPU select ARCH_HAS_FAST_MULTIPLIER select PPC_64S_HASH_MMU -config GENERIC_CPU +config POWERPC_CPU bool "Generic 32 bits powerpc" - depends on PPC32 && !PPC_8xx + depends on PPC32 && !PPC_8xx && !PPC_85xx config CELL_CPU bool "Cell Broadband Engine" @@ -196,11 +196,23 @@ config G4_CPU depends on PPC_BOOK3S_32 select ALTIVEC +config E500_CPU + bool "e500 (8540)" + depends on PPC_85xx && !PPC_E500MC + +config E500MC_CPU + bool "e500mc" + depends on PPC_85xx && PPC_E500MC + +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 + default !GENERIC_CPU && !TOOLCHAIN_DEFAULT_CPU config TARGET_CPU string @@ -215,6 +227,9 @@ config TARGET_CPU default "e300c2" if E300C2_CPU default "e300c3" if E300C3_CPU default "G4" if G4_CPU + default "8540" if E500_CPU + default "e500mc" if E500MC_CPU + default "powerpc" if POWERPC_CPU config PPC_BOOK3S def_bool y -- 2.36.1
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com> Cc: "Arnd Bergmann" <arnd@arndb.de>, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Pali Rohár" <pali@kernel.org> Subject: [PATCH v1 2/5] powerpc/32: Don't always pass -mcpu=powerpc to the compiler Date: Mon, 11 Jul 2022 16:19:30 +0200 [thread overview] Message-ID: <d4df724691351531bf46d685d654689e5dfa0d74.1657549153.git.christophe.leroy@csgroup.eu> (raw) In-Reply-To: <8abab4888da69ff78b73a56f64d9678a7bf684e9.1657549153.git.christophe.leroy@csgroup.eu> Since commit 4bf4f42a2feb ("powerpc/kbuild: Set default generic machine type for 32-bit compile"), when building a 32 bits kernel with a bi-arch version of GCC, or when building a book3s/32 kernel, the option -mcpu=powerpc is passed to GCC at all time, relying on it being eventually overriden by a subsequent -mcpu=xxxx. But when building the same kernel with a 32 bits only version of GCC, that is not done, relying on gcc being built with the expected default CPU. This logic has two problems. First, it is a bit fragile to rely on whether the GCC version is bi-arch or not, because today we can have bi-arch versions of GCC configured with a 32 bits default. Second, there are some versions of GCC which don't support -mcpu=powerpc, for instance for e500 SPE-only versions. So, stop relying on this approximative logic and allow the user to decide whether he/she wants to use the toolchain's default CPU or if he/she wants to set one, and allow only possible CPUs based on the selected target. Reported-by: Pali Rohár <pali@kernel.org> Tested-by: Pali Rohár <pali@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/Makefile | 26 +------------------------- arch/powerpc/platforms/Kconfig.cputype | 21 ++++++++++++++++++--- 2 files changed, 19 insertions(+), 28 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index a0cd70712061..d54e1fe03551 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -15,23 +15,6 @@ HAS_BIARCH := $(call cc-option-yn, -m32) # Set default 32 bits cross compilers for vdso and boot wrapper CROSS32_COMPILE ?= -ifeq ($(HAS_BIARCH),y) -ifeq ($(CROSS32_COMPILE),) -ifdef CONFIG_PPC32 -# These options will be overridden by any -mcpu option that the CPU -# or platform code sets later on the command line, but they are needed -# to set a sane 32-bit cpu target for the 64-bit cross compiler which -# may default to the wrong ISA. -KBUILD_CFLAGS += -mcpu=powerpc -KBUILD_AFLAGS += -mcpu=powerpc -endif -endif -endif - -ifdef CONFIG_PPC_BOOK3S_32 -KBUILD_CFLAGS += -mcpu=powerpc -endif - # If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use # ppc64_defconfig because we have nothing better to go on. uname := $(shell uname -m) @@ -183,6 +166,7 @@ endif endif CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) +AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) # Altivec option not allowed with e500mc64 in GCC. ifdef CONFIG_ALTIVEC @@ -193,14 +177,6 @@ endif CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU) CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU)) -ifdef CONFIG_PPC32 -ifdef CONFIG_PPC_E500MC -CFLAGS-y += $(call cc-option,-mcpu=e500mc,-mcpu=powerpc) -else -CFLAGS-$(CONFIG_E500) += $(call cc-option,-mcpu=8540 -msoft-float,-mcpu=powerpc) -endif -endif - asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1) KBUILD_CPPFLAGS += -I $(srctree)/arch/$(ARCH) $(asinstr) diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 9805a2c717b9..bfea5d8452f8 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -135,9 +135,9 @@ config GENERIC_CPU select ARCH_HAS_FAST_MULTIPLIER select PPC_64S_HASH_MMU -config GENERIC_CPU +config POWERPC_CPU bool "Generic 32 bits powerpc" - depends on PPC32 && !PPC_8xx + depends on PPC32 && !PPC_8xx && !PPC_85xx config CELL_CPU bool "Cell Broadband Engine" @@ -196,11 +196,23 @@ config G4_CPU depends on PPC_BOOK3S_32 select ALTIVEC +config E500_CPU + bool "e500 (8540)" + depends on PPC_85xx && !PPC_E500MC + +config E500MC_CPU + bool "e500mc" + depends on PPC_85xx && PPC_E500MC + +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 + default !GENERIC_CPU && !TOOLCHAIN_DEFAULT_CPU config TARGET_CPU string @@ -215,6 +227,9 @@ config TARGET_CPU default "e300c2" if E300C2_CPU default "e300c3" if E300C3_CPU default "G4" if G4_CPU + default "8540" if E500_CPU + default "e500mc" if E500MC_CPU + default "powerpc" if POWERPC_CPU config PPC_BOOK3S def_bool y -- 2.36.1
next prev parent reply other threads:[~2022-07-11 14:20 UTC|newest] Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-11 14:19 [PATCH v1 1/5] powerpc/32: Do not allow selection of e5500 or e6500 CPUs on PPC32 Christophe Leroy 2022-07-11 14:19 ` Christophe Leroy 2022-07-11 14:19 ` Christophe Leroy [this message] 2022-07-11 14:19 ` [PATCH v1 2/5] powerpc/32: Don't always pass -mcpu=powerpc to the compiler Christophe Leroy 2022-07-11 16:50 ` Segher Boessenkool 2022-07-11 16:50 ` Segher Boessenkool 2022-08-18 17:46 ` Pali Rohár 2022-08-18 17:46 ` Pali Rohár 2022-08-20 10:55 ` Pali Rohár 2022-08-20 10:55 ` Pali Rohár 2022-07-11 14:19 ` [PATCH v1 3/5] powerpc/405: Fix build failure with GCC 12 (unrecognized opcode: `wrteei') Christophe Leroy 2022-07-11 14:19 ` Christophe Leroy 2022-07-11 14:19 ` [PATCH v1 4/5] powerpc/44x: " Christophe Leroy 2022-07-11 14:19 ` Christophe Leroy 2022-07-11 15:05 ` Arnd Bergmann 2022-07-11 15:05 ` Arnd Bergmann 2022-07-11 15:49 ` Christophe Leroy 2022-07-11 15:49 ` Christophe Leroy 2022-07-11 17:12 ` Segher Boessenkool 2022-07-11 17:12 ` Segher Boessenkool 2022-07-11 14:19 ` [PATCH v1 5/5] powerpc/64e: " Christophe Leroy 2022-07-11 14:19 ` Christophe Leroy 2022-12-11 17:32 ` Pali Rohár 2022-12-11 17:32 ` Pali Rohár 2022-12-12 7:36 ` Christophe Leroy 2022-12-12 7:36 ` Christophe Leroy 2022-12-12 10:27 ` Michael Ellerman 2022-12-12 10:27 ` Michael Ellerman 2022-07-11 16:39 ` [PATCH v1 1/5] powerpc/32: Do not allow selection of e5500 or e6500 CPUs on PPC32 Segher Boessenkool 2022-07-11 16:39 ` Segher Boessenkool 2022-07-11 17:42 ` Christophe Leroy 2022-07-11 17:42 ` Christophe Leroy 2022-07-29 13:02 ` Michael Ellerman
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