diff options
Diffstat (limited to 'arch/frv/kernel/switch_to.S')
| -rw-r--r-- | arch/frv/kernel/switch_to.S | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/arch/frv/kernel/switch_to.S b/arch/frv/kernel/switch_to.S new file mode 100644 index 00000000000..1703dc20174 --- /dev/null +++ b/arch/frv/kernel/switch_to.S @@ -0,0 +1,496 @@ +############################################################################### +# +# switch_to.S: context switch operation +# +# Copyright (C) 2003 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 License +# as published by the Free Software Foundation; either version +# 2 of the License, or (at your option) any later version. +# +############################################################################### +#include <linux/config.h> +#include <linux/linkage.h> +#include <asm/thread_info.h> +#include <asm/processor.h> +#include <asm/registers.h> +#include <asm/spr-regs.h> + +.macro LEDS val + setlos #~\val,gr27 + st gr27,@(gr30,gr0) + membar + dcf @(gr30,gr0) +.endm + + .section .sdata + .balign 8 + + # address of frame 0 (userspace) on current kernel stack + .globl __kernel_frame0_ptr +__kernel_frame0_ptr: + .long init_thread_union + THREAD_SIZE - USER_CONTEXT_SIZE + + # address of current task + .globl __kernel_current_task +__kernel_current_task: + .long init_task + + .section .text + .balign 4 + +############################################################################### +# +# struct task_struct *__switch_to(struct thread_struct *prev_thread, +# struct thread_struct *next_thread, +# struct task_struct *prev) +# +############################################################################### + .globl __switch_to +__switch_to: + # save outgoing process's context + sethi.p %hi(__switch_back),gr13 + setlo %lo(__switch_back),gr13 + movsg lr,gr12 + + stdi gr28,@(gr8,#__THREAD_FRAME) + sti sp ,@(gr8,#__THREAD_SP) + sti fp ,@(gr8,#__THREAD_FP) + stdi gr12,@(gr8,#__THREAD_LR) + stdi gr16,@(gr8,#__THREAD_GR(16)) + stdi gr18,@(gr8,#__THREAD_GR(18)) + stdi gr20,@(gr8,#__THREAD_GR(20)) + stdi gr22,@(gr8,#__THREAD_GR(22)) + stdi gr24,@(gr8,#__THREAD_GR(24)) + stdi.p gr26,@(gr8,#__THREAD_GR(26)) + + or gr8,gr8,gr22 + ldi.p @(gr8,#__THREAD_USER),gr8 + call save_user_regs + or gr22,gr22,gr8 + + # retrieve the new context + sethi.p %hi(__kernel_frame0_ptr),gr6 + setlo %lo(__kernel_frame0_ptr),gr6 + movsg psr,gr4 + + lddi.p @(gr9,#__THREAD_FRAME),gr10 + or gr10,gr10,gr27 ; save prev for the return value + + ldi @(gr11,#4),gr19 ; get new_current->thread_info + + lddi @(gr9,#__THREAD_SP),gr12 + ldi @(gr9,#__THREAD_LR),gr14 + ldi @(gr9,#__THREAD_PC),gr18 + ldi.p @(gr9,#__THREAD_FRAME0),gr7 + + # actually switch kernel contexts with ordinary exceptions disabled + andi gr4,#~PSR_ET,gr5 + movgs gr5,psr + + or.p gr10,gr0,gr28 ; set __frame + or gr11,gr0,gr29 ; set __current + or.p gr12,gr0,sp + or gr13,gr0,fp + or gr19,gr0,gr15 ; set __current_thread_info + + sti gr7,@(gr6,#0) ; set __kernel_frame0_ptr + sti gr29,@(gr6,#4) ; set __kernel_current_task + + movgs gr14,lr + bar + + srli gr15,#28,gr5 + subicc gr5,#0xc,gr0,icc0 + beq icc0,#0,111f + break + nop +111: + + # jump to __switch_back or ret_from_fork as appropriate + # - move prev to GR8 + movgs gr4,psr + jmpl.p @(gr18,gr0) + or gr27,gr27,gr8 + +############################################################################### +# +# restore incoming process's context +# - on entry: +# - SP, FP, LR, GR15, GR28 and GR29 will have been set up appropriately +# - GR8 will point to the outgoing task_struct +# - GR9 will point to the incoming thread_struct +# +############################################################################### +__switch_back: + lddi @(gr9,#__THREAD_GR(16)),gr16 + lddi @(gr9,#__THREAD_GR(18)),gr18 + lddi @(gr9,#__THREAD_GR(20)),gr20 + lddi @(gr9,#__THREAD_GR(22)),gr22 + lddi @(gr9,#__THREAD_GR(24)),gr24 + lddi @(gr9,#__THREAD_GR(26)),gr26 + + # fall through into restore_user_regs() + ldi.p @(gr9,#__THREAD_USER),gr8 + or gr8,gr8,gr9 + +############################################################################### +# +# restore extra general regs and FP/Media regs +# - void *restore_user_regs(const struct user_context *target, void *retval) +# - on entry: +# - GR8 will point to the user context to swap in +# - GR9 will contain the value to be returned in GR8 (prev task on context switch) +# +############################################################################### + .globl restore_user_regs +restore_user_regs: + movsg hsr0,gr6 + ori gr6,#HSR0_GRHE|HSR0_FRLE|HSR0_FRHE,gr6 + movgs gr6,hsr0 + movsg hsr0,gr6 + + movsg psr,gr7 + ori gr7,#PSR_EF|PSR_EM,gr7 + movgs gr7,psr + movsg psr,gr7 + srli gr7,#24,gr7 + bar + + lddi @(gr8,#__FPMEDIA_MSR(0)),gr4 + + movgs gr4,msr0 + movgs gr5,msr1 + + lddfi @(gr8,#__FPMEDIA_ACC(0)),fr16 + lddfi @(gr8,#__FPMEDIA_ACC(2)),fr18 + ldbfi @(gr8,#__FPMEDIA_ACCG(0)),fr20 + ldbfi @(gr8,#__FPMEDIA_ACCG(1)),fr21 + ldbfi @(gr8,#__FPMEDIA_ACCG(2)),fr22 + ldbfi @(gr8,#__FPMEDIA_ACCG(3)),fr23 + + mwtacc fr16,acc0 + mwtacc fr17,acc1 + mwtacc fr18,acc2 + mwtacc fr19,acc3 + mwtaccg fr20,accg0 + mwtaccg fr21,accg1 + mwtaccg fr22,accg2 + mwtaccg fr23,accg3 + + # some CPUs have extra ACCx and ACCGx regs and maybe FSRx regs + subicc.p gr7,#0x50,gr0,icc0 + subicc gr7,#0x31,gr0,icc1 + beq icc0,#0,__restore_acc_fr451 + beq icc1,#0,__restore_acc_fr555 +__restore_acc_cont: + + # some CPU's have GR32-GR63 + setlos #HSR0_FRHE,gr4 + andcc gr6,gr4,gr0,icc0 + beq icc0,#1,__restore_skip_gr32_gr63 + + lddi @(gr8,#__INT_GR(32)),gr32 + lddi @(gr8,#__INT_GR(34)),gr34 + lddi @(gr8,#__INT_GR(36)),gr36 + lddi @(gr8,#__INT_GR(38)),gr38 + lddi @(gr8,#__INT_GR(40)),gr40 + lddi @(gr8,#__INT_GR(42)),gr42 + lddi @(gr8,#__INT_GR(44)),gr44 + lddi @(gr8,#__INT_GR(46)),gr46 + lddi @(gr8,#__INT_GR(48)),gr48 + lddi @(gr8,#__INT_GR(50)),gr50 + lddi @(gr8,#__INT_GR(52)),gr52 + lddi @(gr8,#__INT_GR(54)),gr54 + lddi @(gr8,#__INT_GR(56)),gr56 + lddi @(gr8,#__INT_GR(58)),gr58 + lddi @(gr8,#__INT_GR(60)),gr60 + lddi @(gr8,#__INT_GR(62)),gr62 +__restore_skip_gr32_gr63: + + # all CPU's have FR0-FR31 + lddfi @(gr8,#__FPMEDIA_FR( 0)),fr0 + lddfi @(gr8,#__FPMEDIA_FR( 2)),fr2 + lddfi @(gr8,#__FPMEDIA_FR( 4)),fr4 + lddfi @(gr8,#__FPMEDIA_FR( 6)),fr6 + lddfi @(gr8,#__FPMEDIA_FR( 8)),fr8 + lddfi @(gr8,#__FPMEDIA_FR(10)),fr10 + lddfi @(gr8,#__FPMEDIA_FR(12)),fr12 + lddfi @(gr8,#__FPMEDIA_FR(14)),fr14 + lddfi @(gr8,#__FPMEDIA_FR(16)),fr16 + lddfi @(gr8,#__FPMEDIA_FR(18)),fr18 + lddfi @(gr8,#__FPMEDIA_FR(20)),fr20 + lddfi @(gr8,#__FPMEDIA_FR(22)),fr22 + lddfi @(gr8,#__FPMEDIA_FR(24)),fr24 + lddfi @(gr8,#__FPMEDIA_FR(26)),fr26 + lddfi @(gr8,#__FPMEDIA_FR(28)),fr28 + lddfi.p @(gr8,#__FPMEDIA_FR(30)),fr30 + + # some CPU's have FR32-FR63 + setlos #HSR0_FRHE,gr4 + andcc gr6,gr4,gr0,icc0 + beq icc0,#1,__restore_skip_fr32_fr63 + + lddfi @(gr8,#__FPMEDIA_FR(32)),fr32 + lddfi @(gr8,#__FPMEDIA_FR(34)),fr34 + lddfi @(gr8,#__FPMEDIA_FR(36)),fr36 + lddfi @(gr8,#__FPMEDIA_FR(38)),fr38 + lddfi @(gr8,#__FPMEDIA_FR(40)),fr40 + lddfi @(gr8,#__FPMEDIA_FR(42)),fr42 + lddfi @(gr8,#__FPMEDIA_FR(44)),fr44 + lddfi @(gr8,#__FPMEDIA_FR(46)),fr46 + lddfi @(gr8,#__FPMEDIA_FR(48)),fr48 + lddfi @(gr8,#__FPMEDIA_FR(50)),fr50 + lddfi @(gr8,#__FPMEDIA_FR(52)),fr52 + lddfi @(gr8,#__FPMEDIA_FR(54)),fr54 + lddfi @(gr8,#__FPMEDIA_FR(56)),fr56 + lddfi @(gr8,#__FPMEDIA_FR(58)),fr58 + lddfi @(gr8,#__FPMEDIA_FR(60)),fr60 + lddfi @(gr8,#__FPMEDIA_FR(62)),fr62 +__restore_skip_fr32_fr63: + + lddi @(gr8,#__FPMEDIA_FNER(0)),gr4 + movsg fner0,gr4 + movsg fner1,gr5 + or.p gr9,gr9,gr8 + bralr + + # the FR451 also has ACC8-11/ACCG8-11 regs (but not 4-7...) +__restore_acc_fr451: + lddfi @(gr8,#__FPMEDIA_ACC(4)),fr16 + lddfi @(gr8,#__FPMEDIA_ACC(6)),fr18 + ldbfi @(gr8,#__FPMEDIA_ACCG(4)),fr20 + ldbfi @(gr8,#__FPMEDIA_ACCG(5)),fr21 + ldbfi @(gr8,#__FPMEDIA_ACCG(6)),fr22 + ldbfi @(gr8,#__FPMEDIA_ACCG(7)),fr23 + + mwtacc fr16,acc8 + mwtacc fr17,acc9 + mwtacc fr18,acc10 + mwtacc fr19,acc11 + mwtaccg fr20,accg8 + mwtaccg fr21,accg9 + mwtaccg fr22,accg10 + mwtaccg fr23,accg11 + bra __restore_acc_cont + + # the FR555 also has ACC4-7/ACCG4-7 regs and an FSR0 reg +__restore_acc_fr555: + lddfi @(gr8,#__FPMEDIA_ACC(4)),fr16 + lddfi @(gr8,#__FPMEDIA_ACC(6)),fr18 + ldbfi @(gr8,#__FPMEDIA_ACCG(4)),fr20 + ldbfi @(gr8,#__FPMEDIA_ACCG(5)),fr21 + ldbfi @(gr8,#__FPMEDIA_ACCG(6)),fr22 + ldbfi @(gr8,#__FPMEDIA_ACCG(7)),fr23 + + mnop.p + mwtacc fr16,acc4 + mnop.p + mwtacc fr17,acc5 + mnop.p + mwtacc fr18,acc6 + mnop.p + mwtacc fr19,acc7 + mnop.p + mwtaccg fr20,accg4 + mnop.p + mwtaccg fr21,accg5 + mnop.p + mwtaccg fr22,accg6 + mnop.p + mwtaccg fr23,accg7 + + ldi @(gr8,#__FPMEDIA_FSR(0)),gr4 + movgs gr4,fsr0 + + bra __restore_acc_cont + + +############################################################################### +# +# save extra general regs and FP/Media regs +# - void save_user_regs(struct user_context *target) +# +############################################################################### + .globl save_user_regs +save_user_regs: + movsg hsr0,gr6 + ori gr6,#HSR0_GRHE|HSR0_FRLE|HSR0_FRHE,gr6 + movgs gr6,hsr0 + movsg hsr0,gr6 + + movsg psr,gr7 + ori gr7,#PSR_EF|PSR_EM,gr7 + movgs gr7,psr + movsg psr,gr7 + srli gr7,#24,gr7 + bar + + movsg fner0,gr4 + movsg fner1,gr5 + stdi.p gr4,@(gr8,#__FPMEDIA_FNER(0)) + + # some CPU's have GR32-GR63 + setlos #HSR0_GRHE,gr4 + andcc gr6,gr4,gr0,icc0 + beq icc0,#1,__save_skip_gr32_gr63 + + stdi gr32,@(gr8,#__INT_GR(32)) + stdi gr34,@(gr8,#__INT_GR(34)) + stdi gr36,@(gr8,#__INT_GR(36)) + stdi gr38,@(gr8,#__INT_GR(38)) + stdi gr40,@(gr8,#__INT_GR(40)) + stdi gr42,@(gr8,#__INT_GR(42)) + stdi gr44,@(gr8,#__INT_GR(44)) + stdi gr46,@(gr8,#__INT_GR(46)) + stdi gr48,@(gr8,#__INT_GR(48)) + stdi gr50,@(gr8,#__INT_GR(50)) + stdi gr52,@(gr8,#__INT_GR(52)) + stdi gr54,@(gr8,#__INT_GR(54)) + stdi gr56,@(gr8,#__INT_GR(56)) + stdi gr58,@(gr8,#__INT_GR(58)) + stdi gr60,@(gr8,#__INT_GR(60)) + stdi gr62,@(gr8,#__INT_GR(62)) +__save_skip_gr32_gr63: + + # all CPU's have FR0-FR31 + stdfi fr0 ,@(gr8,#__FPMEDIA_FR( 0)) + stdfi fr2 ,@(gr8,#__FPMEDIA_FR( 2)) + stdfi fr4 ,@(gr8,#__FPMEDIA_FR( 4)) + stdfi fr6 ,@(gr8,#__FPMEDIA_FR( 6)) + stdfi fr8 ,@(gr8,#__FPMEDIA_FR( 8)) + stdfi fr10,@(gr8,#__FPMEDIA_FR(10)) + stdfi fr12,@(gr8,#__FPMEDIA_FR(12)) + stdfi fr14,@(gr8,#__FPMEDIA_FR(14)) + stdfi fr16,@(gr8,#__FPMEDIA_FR(16)) + stdfi fr18,@(gr8,#__FPMEDIA_FR(18)) + stdfi fr20,@(gr8,#__FPMEDIA_FR(20)) + stdfi fr22,@(gr8,#__FPMEDIA_FR(22)) + stdfi fr24,@(gr8,#__FPMEDIA_FR(24)) + stdfi fr26,@(gr8,#__FPMEDIA_FR(26)) + stdfi fr28,@(gr8,#__FPMEDIA_FR(28)) + stdfi.p fr30,@(gr8,#__FPMEDIA_FR(30)) + + # some CPU's have FR32-FR63 + setlos #HSR0_FRHE,gr4 + andcc gr6,gr4,gr0,icc0 + beq icc0,#1,__save_skip_fr32_fr63 + + stdfi fr32,@(gr8,#__FPMEDIA_FR(32)) + stdfi fr34,@(gr8,#__FPMEDIA_FR(34)) + stdfi fr36,@(gr8,#__FPMEDIA_FR(36)) + stdfi fr38,@(gr8,#__FPMEDIA_FR(38)) + stdfi fr40,@(gr8,#__FPMEDIA_FR(40)) + stdfi fr42,@(gr8,#__FPMEDIA_FR(42)) + stdfi fr44,@(gr8,#__FPMEDIA_FR(44)) + stdfi fr46,@(gr8,#__FPMEDIA_FR(46)) + stdfi fr48,@(gr8,#__FPMEDIA_FR(48)) + stdfi fr50,@(gr8,#__FPMEDIA_FR(50)) + stdfi fr52,@(gr8,#__FPMEDIA_FR(52)) + stdfi fr54,@(gr8,#__FPMEDIA_FR(54)) + stdfi fr56,@(gr8,#__FPMEDIA_FR(56)) + stdfi fr58,@(gr8,#__FPMEDIA_FR(58)) + stdfi fr60,@(gr8,#__FPMEDIA_FR(60)) + stdfi fr62,@(gr8,#__FPMEDIA_FR(62)) +__save_skip_fr32_fr63: + + mrdacc acc0 ,fr4 + mrdacc acc1 ,fr5 + + stdfi.p fr4 ,@(gr8,#__FPMEDIA_ACC(0)) + + mrdacc acc2 ,fr6 + mrdacc acc3 ,fr7 + + stdfi.p fr6 ,@(gr8,#__FPMEDIA_ACC(2)) + + mrdaccg accg0,fr4 + stbfi.p fr4 ,@(gr8,#__FPMEDIA_ACCG(0)) + + mrdaccg accg1,fr5 + stbfi.p fr5 ,@(gr8,#__FPMEDIA_ACCG(1)) + + mrdaccg accg2,fr6 + stbfi.p fr6 ,@(gr8,#__FPMEDIA_ACCG(2)) + + mrdaccg accg3,fr7 + stbfi fr7 ,@(gr8,#__FPMEDIA_ACCG(3)) + + movsg msr0 ,gr4 + movsg msr1 ,gr5 + + stdi gr4 ,@(gr8,#__FPMEDIA_MSR(0)) + + # some CPUs have extra ACCx and ACCGx regs and maybe FSRx regs + subicc.p gr7,#0x50,gr0,icc0 + subicc gr7,#0x31,gr0,icc1 + beq icc0,#0,__save_acc_fr451 + beq icc1,#0,__save_acc_fr555 +__save_acc_cont: + + lddfi @(gr8,#__FPMEDIA_FR(4)),fr4 + lddfi.p @(gr8,#__FPMEDIA_FR(6)),fr6 + bralr + + # the FR451 also has ACC8-11/ACCG8-11 regs (but not 4-7...) +__save_acc_fr451: + mrdacc acc8 ,fr4 + mrdacc acc9 ,fr5 + + stdfi.p fr4 ,@(gr8,#__FPMEDIA_ACC(4)) + + mrdacc acc10,fr6 + mrdacc acc11,fr7 + + stdfi.p fr6 ,@(gr8,#__FPMEDIA_ACC(6)) + + mrdaccg accg8,fr4 + stbfi.p fr4 ,@(gr8,#__FPMEDIA_ACCG(4)) + + mrdaccg accg9,fr5 + stbfi.p fr5 ,@(gr8,#__FPMEDIA_ACCG(5)) + + mrdaccg accg10,fr6 + stbfi.p fr6 ,@(gr8,#__FPMEDIA_ACCG(6)) + + mrdaccg accg11,fr7 + stbfi fr7 ,@(gr8,#__FPMEDIA_ACCG(7)) + bra __save_acc_cont + + # the FR555 also has ACC4-7/ACCG4-7 regs and an FSR0 reg +__save_acc_fr555: + mnop.p + mrdacc acc4 ,fr4 + mnop.p + mrdacc acc5 ,fr5 + + stdfi fr4 ,@(gr8,#__FPMEDIA_ACC(4)) + + mnop.p + mrdacc acc6 ,fr6 + mnop.p + mrdacc acc7 ,fr7 + + stdfi fr6 ,@(gr8,#__FPMEDIA_ACC(6)) + + mnop.p + mrdaccg accg4,fr4 + stbfi fr4 ,@(gr8,#__FPMEDIA_ACCG(4)) + + mnop.p + mrdaccg accg5,fr5 + stbfi fr5 ,@(gr8,#__FPMEDIA_ACCG(5)) + + mnop.p + mrdaccg accg6,fr6 + stbfi fr6 ,@(gr8,#__FPMEDIA_ACCG(6)) + + mnop.p + mrdaccg accg7,fr7 + stbfi fr7 ,@(gr8,#__FPMEDIA_ACCG(7)) + + movsg fsr0 ,gr4 + sti gr4 ,@(gr8,#__FPMEDIA_FSR(0)) + bra __save_acc_cont |