linux/arch/mips/kernel/r6000_fpu.S
Maciej W. Rozycki 758ef0a939 MIPS: Fix ISA I/II FP signal context offsets
Fix a regression introduced with commit 2db9ca0a35 ("MIPS: Use struct
mips_abi offsets to save FP context") for MIPS I/I FP signal contexts,
by converting save/restore code to the updated internal API.  Start FGR
offsets from 0 rather than SC_FPREGS from $a0 and use $a1 rather than
the offset of SC_FPC_CSR from $a0 for the Floating Point Control/Status
Register (FCSR).

Document the new internal API and adjust assembly code formatting for
consistency.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14476/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04 01:38:52 +01:00

100 lines
2.1 KiB
ArmAsm

/*
* r6000_fpu.S: Save/restore floating point context for signal handlers.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996 by Ralf Baechle
*
* Multi-arch abstraction and asm macros for easier reading:
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*/
#include <asm/asm.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
.set noreorder
.set mips2
.set push
SET_HARDFLOAT
/**
* _save_fp_context() - save FP context from the FPU
* @a0 - pointer to fpregs field of sigcontext
* @a1 - pointer to fpc_csr field of sigcontext
*
* Save FP context, including the 32 FP data registers and the FP
* control & status register, from the FPU to signal context.
*/
LEAF(_save_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
bgez t0,1f
nop
cfc1 t1,fcr31
/* Store the 16 double precision registers */
sdc1 $f0,0(a0)
sdc1 $f2,16(a0)
sdc1 $f4,32(a0)
sdc1 $f6,48(a0)
sdc1 $f8,64(a0)
sdc1 $f10,80(a0)
sdc1 $f12,96(a0)
sdc1 $f14,112(a0)
sdc1 $f16,128(a0)
sdc1 $f18,144(a0)
sdc1 $f20,160(a0)
sdc1 $f22,176(a0)
sdc1 $f24,192(a0)
sdc1 $f26,208(a0)
sdc1 $f28,224(a0)
sdc1 $f30,240(a0)
jr ra
sw t0,(a1)
1: jr ra
nop
END(_save_fp_context)
/**
* _restore_fp_context() - restore FP context to the FPU
* @a0 - pointer to fpregs field of sigcontext
* @a1 - pointer to fpc_csr field of sigcontext
*
* Restore FP context, including the 32 FP data registers and the FP
* control & status register, from signal context to the FPU.
*/
LEAF(_restore_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
bgez t0,1f
lw t0,(a1)
/* Restore the 16 double precision registers */
ldc1 $f0,0(a0)
ldc1 $f2,16(a0)
ldc1 $f4,32(a0)
ldc1 $f6,48(a0)
ldc1 $f8,64(a0)
ldc1 $f10,80(a0)
ldc1 $f12,96(a0)
ldc1 $f14,112(a0)
ldc1 $f16,128(a0)
ldc1 $f18,144(a0)
ldc1 $f20,160(a0)
ldc1 $f22,176(a0)
ldc1 $f24,192(a0)
ldc1 $f26,208(a0)
ldc1 $f28,224(a0)
ldc1 $f30,240(a0)
jr ra
ctc1 t0,fcr31
1: jr ra
nop
END(_restore_fp_context)
.set pop /* SET_HARDFLOAT */