linux/arch/mips/kernel/r4k_fpu.S
Paul Burton 16f77de82f Revert "MIPS: Save/restore MSA context around signals"
This reverts commit eec43a224c "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649e0 "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).

The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.

This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.

[ralf@linux-mips.org: Fixed rejects.]

Cc: stable@vger.kernel.org
Reported-by: Joseph S. Myers <joseph@codesourcery.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-06-26 10:48:18 +01:00

255 lines
6.8 KiB
ArmAsm

/*
* 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, 98, 99, 2000, 01 Ralf Baechle
*
* Multi-arch abstraction and asm macros for easier reading:
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc.
* Copyright (C) 1999, 2001 Silicon Graphics, Inc.
*/
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
.macro EX insn, reg, src
.set push
.set nomacro
.ex\@: \insn \reg, \src
.set pop
.section __ex_table,"a"
PTR .ex\@, fault
.previous
.endm
.set noreorder
.set arch=r4000
LEAF(_save_fp_context)
cfc1 t1, fcr31
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
.set push
#ifdef CONFIG_CPU_MIPS32_R2
.set mips64r2
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip storing odd if FR=0
nop
#endif
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC_FPREGS+8(a0)
EX sdc1 $f3, SC_FPREGS+24(a0)
EX sdc1 $f5, SC_FPREGS+40(a0)
EX sdc1 $f7, SC_FPREGS+56(a0)
EX sdc1 $f9, SC_FPREGS+72(a0)
EX sdc1 $f11, SC_FPREGS+88(a0)
EX sdc1 $f13, SC_FPREGS+104(a0)
EX sdc1 $f15, SC_FPREGS+120(a0)
EX sdc1 $f17, SC_FPREGS+136(a0)
EX sdc1 $f19, SC_FPREGS+152(a0)
EX sdc1 $f21, SC_FPREGS+168(a0)
EX sdc1 $f23, SC_FPREGS+184(a0)
EX sdc1 $f25, SC_FPREGS+200(a0)
EX sdc1 $f27, SC_FPREGS+216(a0)
EX sdc1 $f29, SC_FPREGS+232(a0)
EX sdc1 $f31, SC_FPREGS+248(a0)
1: .set pop
#endif
/* Store the 16 even double precision registers */
EX sdc1 $f0, SC_FPREGS+0(a0)
EX sdc1 $f2, SC_FPREGS+16(a0)
EX sdc1 $f4, SC_FPREGS+32(a0)
EX sdc1 $f6, SC_FPREGS+48(a0)
EX sdc1 $f8, SC_FPREGS+64(a0)
EX sdc1 $f10, SC_FPREGS+80(a0)
EX sdc1 $f12, SC_FPREGS+96(a0)
EX sdc1 $f14, SC_FPREGS+112(a0)
EX sdc1 $f16, SC_FPREGS+128(a0)
EX sdc1 $f18, SC_FPREGS+144(a0)
EX sdc1 $f20, SC_FPREGS+160(a0)
EX sdc1 $f22, SC_FPREGS+176(a0)
EX sdc1 $f24, SC_FPREGS+192(a0)
EX sdc1 $f26, SC_FPREGS+208(a0)
EX sdc1 $f28, SC_FPREGS+224(a0)
EX sdc1 $f30, SC_FPREGS+240(a0)
EX sw t1, SC_FPC_CSR(a0)
jr ra
li v0, 0 # success
END(_save_fp_context)
#ifdef CONFIG_MIPS32_COMPAT
/* Save 32-bit process floating point context */
LEAF(_save_fp_context32)
cfc1 t1, fcr31
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip storing odd if FR=0
nop
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC32_FPREGS+8(a0)
EX sdc1 $f3, SC32_FPREGS+24(a0)
EX sdc1 $f5, SC32_FPREGS+40(a0)
EX sdc1 $f7, SC32_FPREGS+56(a0)
EX sdc1 $f9, SC32_FPREGS+72(a0)
EX sdc1 $f11, SC32_FPREGS+88(a0)
EX sdc1 $f13, SC32_FPREGS+104(a0)
EX sdc1 $f15, SC32_FPREGS+120(a0)
EX sdc1 $f17, SC32_FPREGS+136(a0)
EX sdc1 $f19, SC32_FPREGS+152(a0)
EX sdc1 $f21, SC32_FPREGS+168(a0)
EX sdc1 $f23, SC32_FPREGS+184(a0)
EX sdc1 $f25, SC32_FPREGS+200(a0)
EX sdc1 $f27, SC32_FPREGS+216(a0)
EX sdc1 $f29, SC32_FPREGS+232(a0)
EX sdc1 $f31, SC32_FPREGS+248(a0)
/* Store the 16 even double precision registers */
1: EX sdc1 $f0, SC32_FPREGS+0(a0)
EX sdc1 $f2, SC32_FPREGS+16(a0)
EX sdc1 $f4, SC32_FPREGS+32(a0)
EX sdc1 $f6, SC32_FPREGS+48(a0)
EX sdc1 $f8, SC32_FPREGS+64(a0)
EX sdc1 $f10, SC32_FPREGS+80(a0)
EX sdc1 $f12, SC32_FPREGS+96(a0)
EX sdc1 $f14, SC32_FPREGS+112(a0)
EX sdc1 $f16, SC32_FPREGS+128(a0)
EX sdc1 $f18, SC32_FPREGS+144(a0)
EX sdc1 $f20, SC32_FPREGS+160(a0)
EX sdc1 $f22, SC32_FPREGS+176(a0)
EX sdc1 $f24, SC32_FPREGS+192(a0)
EX sdc1 $f26, SC32_FPREGS+208(a0)
EX sdc1 $f28, SC32_FPREGS+224(a0)
EX sdc1 $f30, SC32_FPREGS+240(a0)
EX sw t1, SC32_FPC_CSR(a0)
cfc1 t0, $0 # implementation/version
EX sw t0, SC32_FPC_EIR(a0)
jr ra
li v0, 0 # success
END(_save_fp_context32)
#endif
/*
* Restore FPU state:
* - fp gp registers
* - cp1 status/control register
*/
LEAF(_restore_fp_context)
EX lw t1, SC_FPC_CSR(a0)
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
.set push
#ifdef CONFIG_CPU_MIPS32_R2
.set mips64r2
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip loading odd if FR=0
nop
#endif
EX ldc1 $f1, SC_FPREGS+8(a0)
EX ldc1 $f3, SC_FPREGS+24(a0)
EX ldc1 $f5, SC_FPREGS+40(a0)
EX ldc1 $f7, SC_FPREGS+56(a0)
EX ldc1 $f9, SC_FPREGS+72(a0)
EX ldc1 $f11, SC_FPREGS+88(a0)
EX ldc1 $f13, SC_FPREGS+104(a0)
EX ldc1 $f15, SC_FPREGS+120(a0)
EX ldc1 $f17, SC_FPREGS+136(a0)
EX ldc1 $f19, SC_FPREGS+152(a0)
EX ldc1 $f21, SC_FPREGS+168(a0)
EX ldc1 $f23, SC_FPREGS+184(a0)
EX ldc1 $f25, SC_FPREGS+200(a0)
EX ldc1 $f27, SC_FPREGS+216(a0)
EX ldc1 $f29, SC_FPREGS+232(a0)
EX ldc1 $f31, SC_FPREGS+248(a0)
1: .set pop
#endif
EX ldc1 $f0, SC_FPREGS+0(a0)
EX ldc1 $f2, SC_FPREGS+16(a0)
EX ldc1 $f4, SC_FPREGS+32(a0)
EX ldc1 $f6, SC_FPREGS+48(a0)
EX ldc1 $f8, SC_FPREGS+64(a0)
EX ldc1 $f10, SC_FPREGS+80(a0)
EX ldc1 $f12, SC_FPREGS+96(a0)
EX ldc1 $f14, SC_FPREGS+112(a0)
EX ldc1 $f16, SC_FPREGS+128(a0)
EX ldc1 $f18, SC_FPREGS+144(a0)
EX ldc1 $f20, SC_FPREGS+160(a0)
EX ldc1 $f22, SC_FPREGS+176(a0)
EX ldc1 $f24, SC_FPREGS+192(a0)
EX ldc1 $f26, SC_FPREGS+208(a0)
EX ldc1 $f28, SC_FPREGS+224(a0)
EX ldc1 $f30, SC_FPREGS+240(a0)
ctc1 t1, fcr31
jr ra
li v0, 0 # success
END(_restore_fp_context)
#ifdef CONFIG_MIPS32_COMPAT
LEAF(_restore_fp_context32)
/* Restore an o32 sigcontext. */
EX lw t1, SC32_FPC_CSR(a0)
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip loading odd if FR=0
nop
EX ldc1 $f1, SC32_FPREGS+8(a0)
EX ldc1 $f3, SC32_FPREGS+24(a0)
EX ldc1 $f5, SC32_FPREGS+40(a0)
EX ldc1 $f7, SC32_FPREGS+56(a0)
EX ldc1 $f9, SC32_FPREGS+72(a0)
EX ldc1 $f11, SC32_FPREGS+88(a0)
EX ldc1 $f13, SC32_FPREGS+104(a0)
EX ldc1 $f15, SC32_FPREGS+120(a0)
EX ldc1 $f17, SC32_FPREGS+136(a0)
EX ldc1 $f19, SC32_FPREGS+152(a0)
EX ldc1 $f21, SC32_FPREGS+168(a0)
EX ldc1 $f23, SC32_FPREGS+184(a0)
EX ldc1 $f25, SC32_FPREGS+200(a0)
EX ldc1 $f27, SC32_FPREGS+216(a0)
EX ldc1 $f29, SC32_FPREGS+232(a0)
EX ldc1 $f31, SC32_FPREGS+248(a0)
1: EX ldc1 $f0, SC32_FPREGS+0(a0)
EX ldc1 $f2, SC32_FPREGS+16(a0)
EX ldc1 $f4, SC32_FPREGS+32(a0)
EX ldc1 $f6, SC32_FPREGS+48(a0)
EX ldc1 $f8, SC32_FPREGS+64(a0)
EX ldc1 $f10, SC32_FPREGS+80(a0)
EX ldc1 $f12, SC32_FPREGS+96(a0)
EX ldc1 $f14, SC32_FPREGS+112(a0)
EX ldc1 $f16, SC32_FPREGS+128(a0)
EX ldc1 $f18, SC32_FPREGS+144(a0)
EX ldc1 $f20, SC32_FPREGS+160(a0)
EX ldc1 $f22, SC32_FPREGS+176(a0)
EX ldc1 $f24, SC32_FPREGS+192(a0)
EX ldc1 $f26, SC32_FPREGS+208(a0)
EX ldc1 $f28, SC32_FPREGS+224(a0)
EX ldc1 $f30, SC32_FPREGS+240(a0)
ctc1 t1, fcr31
jr ra
li v0, 0 # success
END(_restore_fp_context32)
#endif
.set reorder
.type fault@function
.ent fault
fault: li v0, -EFAULT # failure
jr ra
.end fault