![Maciej W. Rozycki](/assets/img/avatar_default.png)
Complement commit 80cbfad790
("MIPS: Correct MIPS I FP context
layout") and correct the way Floating Point General registers are stored
in a signal context with MIPS I hardware.
Use the S.D and L.D assembly macros to have pairs of SWC1 instructions
and pairs of LWC1 instructions produced, respectively, in an arrangement
which makes the memory representation of floating-point data passed
compatible with that used by hardware SDC1 and LDC1 instructions, where
available, regardless of the hardware endianness used. This matches the
layout used by r4k_fpu.S, ensuring run-time compatibility for MIPS I
software across all o32 hardware platforms.
Define an EX2 macro to handle exceptions from both hardware instructions
implicitly produced from S.D and L.D assembly macros.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
111 lines
2.5 KiB
ArmAsm
111 lines
2.5 KiB
ArmAsm
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1996, 1998 by Ralf Baechle
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*
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* Multi-arch abstraction and asm macros for easier reading:
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* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
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*
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* Further modifications to make this work:
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* Copyright (c) 1998 Harald Koerfgen
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*/
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#include <asm/asm.h>
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#include <asm/errno.h>
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#include <asm/fpregdef.h>
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#include <asm/mipsregs.h>
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#include <asm/asm-offsets.h>
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#include <asm/regdef.h>
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#define EX(a,b) \
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9: a,##b; \
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.section __ex_table,"a"; \
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PTR 9b,fault; \
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.previous
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#define EX2(a,b) \
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9: a,##b; \
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.section __ex_table,"a"; \
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PTR 9b,bad_stack; \
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PTR 9b+4,bad_stack; \
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.previous
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.set noreorder
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.set mips1
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/**
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* _save_fp_context() - save FP context from the FPU
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* @a0 - pointer to fpregs field of sigcontext
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* @a1 - pointer to fpc_csr field of sigcontext
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*
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* Save FP context, including the 32 FP data registers and the FP
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* control & status register, from the FPU to signal context.
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*/
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LEAF(_save_fp_context)
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.set push
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SET_HARDFLOAT
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li v0, 0 # assume success
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cfc1 t1, fcr31
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EX2(s.d $f0, 0(a0))
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EX2(s.d $f2, 16(a0))
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EX2(s.d $f4, 32(a0))
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EX2(s.d $f6, 48(a0))
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EX2(s.d $f8, 64(a0))
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EX2(s.d $f10, 80(a0))
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EX2(s.d $f12, 96(a0))
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EX2(s.d $f14, 112(a0))
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EX2(s.d $f16, 128(a0))
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EX2(s.d $f18, 144(a0))
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EX2(s.d $f20, 160(a0))
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EX2(s.d $f22, 176(a0))
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EX2(s.d $f24, 192(a0))
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EX2(s.d $f26, 208(a0))
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EX2(s.d $f28, 224(a0))
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EX2(s.d $f30, 240(a0))
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jr ra
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EX(sw t1, (a1))
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.set pop
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END(_save_fp_context)
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/**
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* _restore_fp_context() - restore FP context to the FPU
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* @a0 - pointer to fpregs field of sigcontext
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* @a1 - pointer to fpc_csr field of sigcontext
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*
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* Restore FP context, including the 32 FP data registers and the FP
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* control & status register, from signal context to the FPU.
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*/
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LEAF(_restore_fp_context)
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.set push
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SET_HARDFLOAT
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li v0, 0 # assume success
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EX(lw t0, (a1))
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EX2(l.d $f0, 0(a0))
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EX2(l.d $f2, 16(a0))
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EX2(l.d $f4, 32(a0))
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EX2(l.d $f6, 48(a0))
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EX2(l.d $f8, 64(a0))
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EX2(l.d $f10, 80(a0))
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EX2(l.d $f12, 96(a0))
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EX2(l.d $f14, 112(a0))
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EX2(l.d $f16, 128(a0))
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EX2(l.d $f18, 144(a0))
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EX2(l.d $f20, 160(a0))
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EX2(l.d $f22, 176(a0))
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EX2(l.d $f24, 192(a0))
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EX2(l.d $f26, 208(a0))
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EX2(l.d $f28, 224(a0))
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EX2(l.d $f30, 240(a0))
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jr ra
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ctc1 t0, fcr31
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.set pop
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END(_restore_fp_context)
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.set reorder
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.type fault, @function
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.ent fault
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fault: li v0, -EFAULT
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jr ra
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.end fault
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