kernel-ark/arch/mn10300/kernel/fpu-low.S
Akira Takeuchi 278d91c460 MN10300: Make the FPU operate in non-lazy mode under SMP
Make the FPU operate in non-lazy mode under SMP so that when the process that
is currently using the FPU migrates to a different CPU, we don't have to ping
its previous CPU to flush the FPU context.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2010-10-27 17:28:52 +01:00

259 lines
5.1 KiB
ArmAsm

/* MN10300 Low level FPU management operations
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/linkage.h>
#include <asm/cpu-regs.h>
#include <asm/smp.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/frame.inc>
.macro FPU_INIT_STATE_ALL
fmov 0,fs0
fmov fs0,fs1
fmov fs0,fs2
fmov fs0,fs3
fmov fs0,fs4
fmov fs0,fs5
fmov fs0,fs6
fmov fs0,fs7
fmov fs0,fs8
fmov fs0,fs9
fmov fs0,fs10
fmov fs0,fs11
fmov fs0,fs12
fmov fs0,fs13
fmov fs0,fs14
fmov fs0,fs15
fmov fs0,fs16
fmov fs0,fs17
fmov fs0,fs18
fmov fs0,fs19
fmov fs0,fs20
fmov fs0,fs21
fmov fs0,fs22
fmov fs0,fs23
fmov fs0,fs24
fmov fs0,fs25
fmov fs0,fs26
fmov fs0,fs27
fmov fs0,fs28
fmov fs0,fs29
fmov fs0,fs30
fmov fs0,fs31
fmov FPCR_INIT,fpcr
.endm
.macro FPU_SAVE_ALL areg,dreg
fmov fs0,(\areg+)
fmov fs1,(\areg+)
fmov fs2,(\areg+)
fmov fs3,(\areg+)
fmov fs4,(\areg+)
fmov fs5,(\areg+)
fmov fs6,(\areg+)
fmov fs7,(\areg+)
fmov fs8,(\areg+)
fmov fs9,(\areg+)
fmov fs10,(\areg+)
fmov fs11,(\areg+)
fmov fs12,(\areg+)
fmov fs13,(\areg+)
fmov fs14,(\areg+)
fmov fs15,(\areg+)
fmov fs16,(\areg+)
fmov fs17,(\areg+)
fmov fs18,(\areg+)
fmov fs19,(\areg+)
fmov fs20,(\areg+)
fmov fs21,(\areg+)
fmov fs22,(\areg+)
fmov fs23,(\areg+)
fmov fs24,(\areg+)
fmov fs25,(\areg+)
fmov fs26,(\areg+)
fmov fs27,(\areg+)
fmov fs28,(\areg+)
fmov fs29,(\areg+)
fmov fs30,(\areg+)
fmov fs31,(\areg+)
fmov fpcr,\dreg
mov \dreg,(\areg)
.endm
.macro FPU_RESTORE_ALL areg,dreg
fmov (\areg+),fs0
fmov (\areg+),fs1
fmov (\areg+),fs2
fmov (\areg+),fs3
fmov (\areg+),fs4
fmov (\areg+),fs5
fmov (\areg+),fs6
fmov (\areg+),fs7
fmov (\areg+),fs8
fmov (\areg+),fs9
fmov (\areg+),fs10
fmov (\areg+),fs11
fmov (\areg+),fs12
fmov (\areg+),fs13
fmov (\areg+),fs14
fmov (\areg+),fs15
fmov (\areg+),fs16
fmov (\areg+),fs17
fmov (\areg+),fs18
fmov (\areg+),fs19
fmov (\areg+),fs20
fmov (\areg+),fs21
fmov (\areg+),fs22
fmov (\areg+),fs23
fmov (\areg+),fs24
fmov (\areg+),fs25
fmov (\areg+),fs26
fmov (\areg+),fs27
fmov (\areg+),fs28
fmov (\areg+),fs29
fmov (\areg+),fs30
fmov (\areg+),fs31
mov (\areg),\dreg
fmov \dreg,fpcr
.endm
###############################################################################
#
# void fpu_init_state(void)
# - initialise the FPU
#
###############################################################################
.globl fpu_init_state
.type fpu_init_state,@function
fpu_init_state:
mov epsw,d0
or EPSW_FE,epsw
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
nop
#endif
FPU_INIT_STATE_ALL
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
nop
#endif
mov d0,epsw
ret [],0
.size fpu_init_state,.-fpu_init_state
###############################################################################
#
# void fpu_save(struct fpu_state_struct *)
# - save the fpu state
# - note that an FPU Operational exception might occur during this process
#
###############################################################################
.globl fpu_save
.type fpu_save,@function
fpu_save:
mov epsw,d1
or EPSW_FE,epsw /* enable the FPU so we can access it */
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
#endif
mov d0,a0
FPU_SAVE_ALL a0,d0
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
#endif
mov d1,epsw
ret [],0
.size fpu_save,.-fpu_save
###############################################################################
#
# void fpu_disabled(void)
# - handle an exception due to the FPU being disabled
# when CONFIG_FPU is enabled
#
###############################################################################
.type fpu_disabled,@function
.globl fpu_disabled
fpu_disabled:
or EPSW_nAR|EPSW_FE,epsw
nop
nop
nop
mov sp,a1
mov (a1),d1 /* get epsw of user context */
and ~(THREAD_SIZE-1),a1 /* a1: (thread_info *ti) */
mov (TI_task,a1),a2 /* a2: (task_struct *tsk) */
btst EPSW_nSL,d1
beq fpu_used_in_kernel
or EPSW_FE,d1
mov d1,(sp)
mov (TASK_THREAD+THREAD_FPU_FLAGS,a2),d1
#ifndef CONFIG_LAZY_SAVE_FPU
or __THREAD_HAS_FPU,d1
mov d1,(TASK_THREAD+THREAD_FPU_FLAGS,a2)
#else /* !CONFIG_LAZY_SAVE_FPU */
mov (fpu_state_owner),a0
cmp 0,a0
beq fpu_regs_save_end
mov (TASK_THREAD+THREAD_UREGS,a0),a1
add TASK_THREAD+THREAD_FPU_STATE,a0
FPU_SAVE_ALL a0,d0
mov (REG_EPSW,a1),d0
and ~EPSW_FE,d0
mov d0,(REG_EPSW,a1)
fpu_regs_save_end:
mov a2,(fpu_state_owner)
#endif /* !CONFIG_LAZY_SAVE_FPU */
btst __THREAD_USING_FPU,d1
beq fpu_regs_init
add TASK_THREAD+THREAD_FPU_STATE,a2
FPU_RESTORE_ALL a2,d0
rti
fpu_regs_init:
FPU_INIT_STATE_ALL
add TASK_THREAD+THREAD_FPU_FLAGS,a2
bset __THREAD_USING_FPU,(0,a2)
rti
fpu_used_in_kernel:
and ~(EPSW_nAR|EPSW_FE),epsw
nop
nop
add -4,sp
SAVE_ALL
mov -1,d0
mov d0,(REG_ORIG_D0,fp)
and ~EPSW_NMID,epsw
mov fp,d0
call fpu_disabled_in_kernel[],0
jmp ret_from_exception
.size fpu_disabled,.-fpu_disabled