| From 2e6c7747730296a6d4fd700894286db1132598c4 Mon Sep 17 00:00:00 2001 |
| From: James Hogan <james.hogan@imgtec.com> |
| Date: Thu, 16 Feb 2017 12:39:01 +0000 |
| Subject: MIPS: Force o32 fp64 support on 32bit MIPS64r6 kernels |
| |
| From: James Hogan <james.hogan@imgtec.com> |
| |
| 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 <james.hogan@imgtec.com> |
| Reviewed-by: Paul Burton <paul.burton@imgtec.com> |
| Cc: Ralf Baechle <ralf@linux-mips.org> |
| Cc: linux-mips@linux-mips.org |
| Patchwork: https://patchwork.linux-mips.org/patch/15310/ |
| Signed-off-by: James Hogan <james.hogan@imgtec.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/mips/Kconfig | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- 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 |
