From: James Hogan Date: Thu, 16 Feb 2017 12:39:01 +0000 (+0000) Subject: MIPS: Force o32 fp64 support on 32bit MIPS64r6 kernels X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~15^2~6 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=394d71b1ea24c248a8d497d10635b86dd2fccef7;p=firefly-linux-kernel-4.4.55.git MIPS: Force o32 fp64 support on 32bit MIPS64r6 kernels commit 2e6c7747730296a6d4fd700894286db1132598c4 upstream. When a 32-bit kernel is configured to support MIPS64r6 (CPU_MIPS64_R6), MIPS_O32_FP64_SUPPORT won't be selected as it should be because MIPS32_O32 is disabled (o32 is already the default ABI available on 32-bit kernels). This results in userland FP breakage as CP0_Status.FR is read-only 1 since r6 (when an FPU is present) so __enable_fpu() will fail to clear FR. This causes the FPU emulator to get used which will incorrectly emulate 32-bit FPU registers. Force o32 fp64 support in this case by also selecting MIPS_O32_FP64_SUPPORT from CPU_MIPS64_R6 if 32BIT. Fixes: 4e9d324d4288 ("MIPS: Require O32 FP64 support for MIPS64 with O32 compat") Signed-off-by: James Hogan Reviewed-by: Paul Burton Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15310/ Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index db459612de44..75bfca69e418 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1412,7 +1412,7 @@ config CPU_MIPS32_R6 select CPU_SUPPORTS_MSA select GENERIC_CSUM select HAVE_KVM - select MIPS_O32_FP64_SUPPORT + select MIPS_O32_FP64_SUPPORT if 32BIT help Choose this option to build a kernel for release 6 or later of the MIPS32 architecture. New MIPS processors, starting with the Warrior