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| author | Paul Burton <paul.burton@imgtec.com> | 2013-11-22 17:12:07 +0400 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2014-01-14 02:40:56 +0400 |
| commit | 597ce1723e0fa0bdbe2ae4c94f18da6e29b92635 (patch) | |
| tree | 21f67268915b8457dd305c6bcf7ac905772fd0ee /arch/mips/include/asm/asmmacro-32.h | |
| parent | 56a22d21bf9744315f56b2bbd6416170f27b7765 (diff) | |
| download | linux-597ce1723e0fa0bdbe2ae4c94f18da6e29b92635.tar.xz | |
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 <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/include/asm/asmmacro-32.h')
| -rw-r--r-- | arch/mips/include/asm/asmmacro-32.h | 42 |
1 files changed, 0 insertions, 42 deletions
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 <asm/fpregdef.h> #include <asm/mipsregs.h> - .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) |