From 57eeacede4db235891ddc37544262413f909763e Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 8 Nov 2018 23:44:55 +0000 Subject: MIPS: Use Kconfig to select CPU_NO_EFFICIENT_FFS Select CONFIG_CPU_NO_EFFICIENT_FFS via Kconfig when the kernel is configured for a pre-MIPS32r1 CPU, rather than defining its equivalent in asm/cpu-features.h based upon overrides of cpu_has_mips* macros. The latter only works if a platform has an cpu-feature-overrides.h header which defines cpu_has_mips* macros, which are not generally needed. There are many cases where we know that the target ISA for a kernel build is MIPS32r1 or later & thus includes the CLZ instruction, without requiring any overrides from the platform. Using Kconfig allows us to take those into account, and more naturally make a decision about instruction support using information about the target ISA. Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/21045/ Cc: Andrew Morton Cc: Zhaoxiu Zeng Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org --- arch/mips/Kconfig | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'arch/mips/Kconfig') diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 513a9c8b6058..6eb17b4a617f 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -15,6 +15,7 @@ config MIPS select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT select CLONE_BACKWARDS + select CPU_NO_EFFICIENT_FFS if (TARGET_ISA_REV < 1) select CPU_PM if CPU_IDLE select DMA_DIRECT_OPS select GENERIC_ATOMIC64 if !64BIT @@ -2031,7 +2032,7 @@ config CPU_MIPS64 default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R6 # -# These two indicate the revision of the architecture, either Release 1 or Release 2 +# These indicate the revision of the architecture # config CPU_MIPSR1 bool @@ -2052,6 +2053,16 @@ config CPU_MIPSR6 select MIPS_CRC_SUPPORT select MIPS_SPRAM +config TARGET_ISA_REV + int + default 1 if CPU_MIPSR1 + default 2 if CPU_MIPSR2 + default 6 if CPU_MIPSR6 + default 0 + help + Reflects the ISA revision being targeted by the kernel build. This + is effectively the Kconfig equivalent of MIPS_ISA_REV. + config EVA bool -- cgit v1.2.3-59-g8ed1b