From 597ce1723e0fa0bdbe2ae4c94f18da6e29b92635 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Fri, 22 Nov 2013 13:12:07 +0000 Subject: MIPS: Support for 64-bit FP with O32 binaries CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/asmmacro-32.h | 42 ------------------------------------- 1 file changed, 42 deletions(-) (limited to 'arch/mips/include/asm/asmmacro-32.h') diff --git a/arch/mips/include/asm/asmmacro-32.h b/arch/mips/include/asm/asmmacro-32.h index 2413afe21b33..70e1f176f123 100644 --- a/arch/mips/include/asm/asmmacro-32.h +++ b/arch/mips/include/asm/asmmacro-32.h @@ -12,27 +12,6 @@ #include #include - .macro fpu_save_double thread status tmp1=t0 - cfc1 \tmp1, fcr31 - sdc1 $f0, THREAD_FPR0(\thread) - sdc1 $f2, THREAD_FPR2(\thread) - sdc1 $f4, THREAD_FPR4(\thread) - sdc1 $f6, THREAD_FPR6(\thread) - sdc1 $f8, THREAD_FPR8(\thread) - sdc1 $f10, THREAD_FPR10(\thread) - sdc1 $f12, THREAD_FPR12(\thread) - sdc1 $f14, THREAD_FPR14(\thread) - sdc1 $f16, THREAD_FPR16(\thread) - sdc1 $f18, THREAD_FPR18(\thread) - sdc1 $f20, THREAD_FPR20(\thread) - sdc1 $f22, THREAD_FPR22(\thread) - sdc1 $f24, THREAD_FPR24(\thread) - sdc1 $f26, THREAD_FPR26(\thread) - sdc1 $f28, THREAD_FPR28(\thread) - sdc1 $f30, THREAD_FPR30(\thread) - sw \tmp1, THREAD_FCR31(\thread) - .endm - .macro fpu_save_single thread tmp=t0 cfc1 \tmp, fcr31 swc1 $f0, THREAD_FPR0(\thread) @@ -70,27 +49,6 @@ sw \tmp, THREAD_FCR31(\thread) .endm - .macro fpu_restore_double thread status tmp=t0 - lw \tmp, THREAD_FCR31(\thread) - ldc1 $f0, THREAD_FPR0(\thread) - ldc1 $f2, THREAD_FPR2(\thread) - ldc1 $f4, THREAD_FPR4(\thread) - ldc1 $f6, THREAD_FPR6(\thread) - ldc1 $f8, THREAD_FPR8(\thread) - ldc1 $f10, THREAD_FPR10(\thread) - ldc1 $f12, THREAD_FPR12(\thread) - ldc1 $f14, THREAD_FPR14(\thread) - ldc1 $f16, THREAD_FPR16(\thread) - ldc1 $f18, THREAD_FPR18(\thread) - ldc1 $f20, THREAD_FPR20(\thread) - ldc1 $f22, THREAD_FPR22(\thread) - ldc1 $f24, THREAD_FPR24(\thread) - ldc1 $f26, THREAD_FPR26(\thread) - ldc1 $f28, THREAD_FPR28(\thread) - ldc1 $f30, THREAD_FPR30(\thread) - ctc1 \tmp, fcr31 - .endm - .macro fpu_restore_single thread tmp=t0 lw \tmp, THREAD_FCR31(\thread) lwc1 $f0, THREAD_FPR0(\thread) -- cgit v1.2.1