diff options
| author | Jiaxun Yang <jiaxun.yang@flygoat.com> | 2024-06-12 10:38:19 +0200 |
|---|---|---|
| committer | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2024-07-12 13:09:25 +0200 |
| commit | 59649de96f21dfb0518faa8feaa3d05c2d81b042 (patch) | |
| tree | 1d46028b969dcb9453ec73c647f7d8a7a22f1a8a /arch/mips/include | |
| parent | MIPS: lantiq: improve USB initialization (diff) | |
| download | linux-59649de96f21dfb0518faa8feaa3d05c2d81b042.tar.xz linux-59649de96f21dfb0518faa8feaa3d05c2d81b042.zip | |
MIPS: Implement ieee754 NAN2008 emulation mode
Implement ieee754 NAN2008 emulation mode.
When this mode is enabled, kernel will accept ELF file
compiled for both NaN 2008 and NaN legacy, but if hardware
does not have capability to match ELF's NaN mode, __own_fpu
will fail for corresponding thread and fpuemu will then kick
in.
This mode trade performance for correctness, while maintaining
support for both NaN mode regardless of hardware capability.
It is useful for multilib installation that have both types
of binary exist in system.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips/include')
| -rw-r--r-- | arch/mips/include/asm/fpu.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h index 86310d6e1035..bc5ac9887d09 100644 --- a/arch/mips/include/asm/fpu.h +++ b/arch/mips/include/asm/fpu.h @@ -129,6 +129,18 @@ static inline int __own_fpu(void) if (ret) return ret; + if (current->thread.fpu.fcr31 & FPU_CSR_NAN2008) { + if (!cpu_has_nan_2008) { + ret = SIGFPE; + goto failed; + } + } else { + if (!cpu_has_nan_legacy) { + ret = SIGFPE; + goto failed; + } + } + KSTK_STATUS(current) |= ST0_CU1; if (mode == FPU_64BIT || mode == FPU_HYBRID) KSTK_STATUS(current) |= ST0_FR; @@ -137,6 +149,9 @@ static inline int __own_fpu(void) set_thread_flag(TIF_USEDFPU); return 0; +failed: + __disable_fpu(); + return ret; } static inline int own_fpu_inatomic(int restore) |