![David Howells](/assets/img/avatar_default.png)
Arrange the sections in the FRV arch so that a BRA instruction with a 16-bit displacement can always reach from the trap table to entry.S, tlb-miss.S and break.S. The problem otherwise is that the linker can insert sufficient code between the slots in the trap table and the targets of the branch instructions in those slots that the displacement field in the instruction isn't sufficiently large. This is because the branch targets were in the .text section along with most of the other code in the kernel. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
793 lines
20 KiB
ArmAsm
793 lines
20 KiB
ArmAsm
/* break.S: Break interrupt handling (kept separate from entry.S)
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*
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* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/linkage.h>
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#include <asm/setup.h>
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#include <asm/segment.h>
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#include <asm/ptrace.h>
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#include <asm/thread_info.h>
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#include <asm/spr-regs.h>
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#include <asm/errno.h>
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#
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# the break handler has its own stack
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#
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.section .bss.stack
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.globl __break_user_context
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.balign THREAD_SIZE
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__break_stack:
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.space THREAD_SIZE - FRV_FRAME0_SIZE
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__break_frame_0:
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.space FRV_FRAME0_SIZE
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#
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# miscellaneous variables
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#
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.section .bss
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#ifdef CONFIG_MMU
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.globl __break_tlb_miss_real_return_info
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__break_tlb_miss_real_return_info:
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.balign 8
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.space 2*4 /* saved PCSR, PSR for TLB-miss handler fixup */
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#endif
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__break_trace_through_exceptions:
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.space 4
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#define CS2_ECS1 0xe1200000
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#define CS2_USERLED 0x4
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.macro LEDS val,reg
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# sethi.p %hi(CS2_ECS1+CS2_USERLED),gr30
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# setlo %lo(CS2_ECS1+CS2_USERLED),gr30
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# setlos #~\val,\reg
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# st \reg,@(gr30,gr0)
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# setlos #0x5555,\reg
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# sethi.p %hi(0xffc00100),gr30
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# setlo %lo(0xffc00100),gr30
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# sth \reg,@(gr30,gr0)
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# membar
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.endm
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###############################################################################
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#
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# entry point for Break Exceptions/Interrupts
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#
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###############################################################################
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.section .text.break
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.balign 4
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.globl __entry_break
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__entry_break:
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#ifdef CONFIG_MMU
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movgs gr31,scr3
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#endif
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LEDS 0x1001,gr31
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sethi.p %hi(__break_frame_0),gr31
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setlo %lo(__break_frame_0),gr31
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stdi gr2,@(gr31,#REG_GR(2))
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movsg ccr,gr3
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sti gr3,@(gr31,#REG_CCR)
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# catch the return from a TLB-miss handler that had single-step disabled
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# traps will be enabled, so we have to do this now
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#ifdef CONFIG_MMU
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movsg bpcsr,gr3
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sethi.p %hi(__break_tlb_miss_return_breaks_here),gr2
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setlo %lo(__break_tlb_miss_return_breaks_here),gr2
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subcc gr2,gr3,gr0,icc0
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beq icc0,#2,__break_return_singlestep_tlbmiss
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#endif
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# determine whether we have stepped through into an exception
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# - we need to take special action to suspend h/w single stepping if we've done
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# that, so that the gdbstub doesn't get bogged down endlessly stepping through
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# external interrupt handling
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movsg bpsr,gr3
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andicc gr3,#BPSR_BET,gr0,icc0
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bne icc0,#2,__break_maybe_userspace /* jump if PSR.ET was 1 */
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LEDS 0x1003,gr2
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movsg brr,gr3
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andicc gr3,#BRR_ST,gr0,icc0
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andicc.p gr3,#BRR_SB,gr0,icc1
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bne icc0,#2,__break_step /* jump if single-step caused break */
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beq icc1,#2,__break_continue /* jump if BREAK didn't cause break */
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LEDS 0x1007,gr2
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# handle special breaks
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movsg bpcsr,gr3
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sethi.p %hi(__entry_return_singlestep_breaks_here),gr2
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setlo %lo(__entry_return_singlestep_breaks_here),gr2
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subcc gr2,gr3,gr0,icc0
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beq icc0,#2,__break_return_singlestep
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bra __break_continue
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###############################################################################
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#
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# handle BREAK instruction in kernel-mode exception epilogue
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#
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###############################################################################
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__break_return_singlestep:
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LEDS 0x100f,gr2
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# special break insn requests single-stepping to be turned back on
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# HERE RETT
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# PSR.ET 0 0
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# PSR.PS old PSR.S ?
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# PSR.S 1 1
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# BPSR.ET 0 1 (can't have caused orig excep otherwise)
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# BPSR.BS 1 old PSR.S
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movsg dcr,gr2
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sethi.p %hi(DCR_SE),gr3
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setlo %lo(DCR_SE),gr3
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or gr2,gr3,gr2
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movgs gr2,dcr
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movsg psr,gr2
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andi gr2,#PSR_PS,gr2
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slli gr2,#11,gr2 /* PSR.PS -> BPSR.BS */
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ori gr2,#BPSR_BET,gr2 /* 1 -> BPSR.BET */
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movgs gr2,bpsr
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# return to the invoker of the original kernel exception
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movsg pcsr,gr2
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movgs gr2,bpcsr
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LEDS 0x101f,gr2
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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lddi.p @(gr31,#REG_GR(2)),gr2
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xor gr31,gr31,gr31
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movgs gr0,brr
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#ifdef CONFIG_MMU
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movsg scr3,gr31
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#endif
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rett #1
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###############################################################################
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#
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# handle BREAK instruction in TLB-miss handler return path
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#
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###############################################################################
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#ifdef CONFIG_MMU
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__break_return_singlestep_tlbmiss:
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LEDS 0x1100,gr2
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sethi.p %hi(__break_tlb_miss_real_return_info),gr3
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setlo %lo(__break_tlb_miss_real_return_info),gr3
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lddi @(gr3,#0),gr2
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movgs gr2,pcsr
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movgs gr3,psr
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bra __break_return_singlestep
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#endif
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###############################################################################
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#
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# handle single stepping into an exception prologue from kernel mode
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# - we try and catch it whilst it is still in the main vector table
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# - if we catch it there, we have to jump to the fixup handler
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# - there is a fixup table that has a pointer for every 16b slot in the trap
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# table
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#
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###############################################################################
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__break_step:
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LEDS 0x2003,gr2
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# external interrupts seem to escape from the trap table before single
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# step catches up with them
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movsg bpcsr,gr2
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sethi.p %hi(__entry_kernel_external_interrupt),gr3
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setlo %lo(__entry_kernel_external_interrupt),gr3
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subcc.p gr2,gr3,gr0,icc0
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sethi %hi(__entry_uspace_external_interrupt),gr3
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setlo.p %lo(__entry_uspace_external_interrupt),gr3
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beq icc0,#2,__break_step_kernel_external_interrupt
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subcc.p gr2,gr3,gr0,icc0
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sethi %hi(__entry_kernel_external_interrupt_virtually_disabled),gr3
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setlo.p %lo(__entry_kernel_external_interrupt_virtually_disabled),gr3
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beq icc0,#2,__break_step_uspace_external_interrupt
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subcc.p gr2,gr3,gr0,icc0
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sethi %hi(__entry_kernel_external_interrupt_virtual_reenable),gr3
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setlo.p %lo(__entry_kernel_external_interrupt_virtual_reenable),gr3
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beq icc0,#2,__break_step_kernel_external_interrupt_virtually_disabled
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subcc gr2,gr3,gr0,icc0
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beq icc0,#2,__break_step_kernel_external_interrupt_virtual_reenable
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LEDS 0x2007,gr2
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# the two main vector tables are adjacent on one 8Kb slab
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movsg bpcsr,gr2
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setlos #0xffffe000,gr3
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and gr2,gr3,gr2
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sethi.p %hi(__trap_tables),gr3
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setlo %lo(__trap_tables),gr3
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subcc gr2,gr3,gr0,icc0
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bne icc0,#2,__break_continue
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LEDS 0x200f,gr2
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# skip workaround if so requested by GDB
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sethi.p %hi(__break_trace_through_exceptions),gr3
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setlo %lo(__break_trace_through_exceptions),gr3
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ld @(gr3,gr0),gr3
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subcc gr3,gr0,gr0,icc0
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bne icc0,#0,__break_continue
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LEDS 0x201f,gr2
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# access the fixup table - there's a 1:1 mapping between the slots in the trap tables and
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# the slots in the trap fixup tables allowing us to simply divide the offset into the
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# former by 4 to access the latter
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sethi.p %hi(__trap_tables),gr3
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setlo %lo(__trap_tables),gr3
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movsg bpcsr,gr2
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sub gr2,gr3,gr2
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srli.p gr2,#2,gr2
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sethi %hi(__trap_fixup_tables),gr3
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setlo.p %lo(__trap_fixup_tables),gr3
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andi gr2,#~3,gr2
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ld @(gr2,gr3),gr2
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jmpil @(gr2,#0)
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# step through an internal exception from kernel mode
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.globl __break_step_kernel_softprog_interrupt
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__break_step_kernel_softprog_interrupt:
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sethi.p %hi(__entry_kernel_softprog_interrupt_reentry),gr3
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setlo %lo(__entry_kernel_softprog_interrupt_reentry),gr3
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bra __break_return_as_kernel_prologue
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# step through an external interrupt from kernel mode
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.globl __break_step_kernel_external_interrupt
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__break_step_kernel_external_interrupt:
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# deal with virtual interrupt disablement
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beq icc2,#0,__break_step_kernel_external_interrupt_virtually_disabled
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sethi.p %hi(__entry_kernel_external_interrupt_reentry),gr3
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setlo %lo(__entry_kernel_external_interrupt_reentry),gr3
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__break_return_as_kernel_prologue:
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LEDS 0x203f,gr2
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movgs gr3,bpcsr
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# do the bit we had to skip
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#ifdef CONFIG_MMU
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movsg ear0,gr2 /* EAR0 can get clobbered by gdb-stub (ICI/ICEI) */
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movgs gr2,scr2
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#endif
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or.p sp,gr0,gr2 /* set up the stack pointer */
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subi sp,#REG__END,sp
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sti.p gr2,@(sp,#REG_SP)
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setlos #REG__STATUS_STEP,gr2
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sti gr2,@(sp,#REG__STATUS) /* record single step status */
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# cancel single-stepping mode
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movsg dcr,gr2
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sethi.p %hi(~DCR_SE),gr3
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setlo %lo(~DCR_SE),gr3
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and gr2,gr3,gr2
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movgs gr2,dcr
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LEDS 0x207f,gr2
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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lddi.p @(gr31,#REG_GR(2)),gr2
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xor gr31,gr31,gr31
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movgs gr0,brr
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#ifdef CONFIG_MMU
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movsg scr3,gr31
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#endif
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rett #1
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# we single-stepped into an interrupt handler whilst interrupts were merely virtually disabled
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# need to really disable interrupts, set flag, fix up and return
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__break_step_kernel_external_interrupt_virtually_disabled:
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movsg psr,gr2
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andi gr2,#~PSR_PIL,gr2
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ori gr2,#PSR_PIL_14,gr2 /* debugging interrupts only */
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movgs gr2,psr
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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subcc.p gr0,gr0,gr0,icc2 /* leave Z set, clear C */
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# exceptions must've been enabled and we must've been in supervisor mode
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setlos BPSR_BET|BPSR_BS,gr3
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movgs gr3,bpsr
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# return to where the interrupt happened
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movsg pcsr,gr2
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movgs gr2,bpcsr
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lddi.p @(gr31,#REG_GR(2)),gr2
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xor gr31,gr31,gr31
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movgs gr0,brr
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#ifdef CONFIG_MMU
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movsg scr3,gr31
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#endif
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rett #1
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# we stepped through into the virtual interrupt reenablement trap
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#
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# we also want to single step anyway, but after fixing up so that we get an event on the
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# instruction after the broken-into exception returns
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.globl __break_step_kernel_external_interrupt_virtual_reenable
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__break_step_kernel_external_interrupt_virtual_reenable:
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movsg psr,gr2
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andi gr2,#~PSR_PIL,gr2
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movgs gr2,psr
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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subicc gr0,#1,gr0,icc2 /* clear Z, set C */
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# save the adjusted ICC2
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movsg ccr,gr3
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sti gr3,@(gr31,#REG_CCR)
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# exceptions must've been enabled and we must've been in supervisor mode
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setlos BPSR_BET|BPSR_BS,gr3
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movgs gr3,bpsr
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# return to where the trap happened
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movsg pcsr,gr2
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movgs gr2,bpcsr
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# and then process the single step
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bra __break_continue
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# step through an internal exception from uspace mode
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.globl __break_step_uspace_softprog_interrupt
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__break_step_uspace_softprog_interrupt:
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sethi.p %hi(__entry_uspace_softprog_interrupt_reentry),gr3
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setlo %lo(__entry_uspace_softprog_interrupt_reentry),gr3
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bra __break_return_as_uspace_prologue
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# step through an external interrupt from kernel mode
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.globl __break_step_uspace_external_interrupt
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__break_step_uspace_external_interrupt:
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sethi.p %hi(__entry_uspace_external_interrupt_reentry),gr3
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setlo %lo(__entry_uspace_external_interrupt_reentry),gr3
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__break_return_as_uspace_prologue:
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LEDS 0x20ff,gr2
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movgs gr3,bpcsr
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# do the bit we had to skip
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sethi.p %hi(__kernel_frame0_ptr),gr28
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setlo %lo(__kernel_frame0_ptr),gr28
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ldi.p @(gr28,#0),gr28
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setlos #REG__STATUS_STEP,gr2
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sti gr2,@(gr28,#REG__STATUS) /* record single step status */
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# cancel single-stepping mode
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movsg dcr,gr2
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sethi.p %hi(~DCR_SE),gr3
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setlo %lo(~DCR_SE),gr3
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and gr2,gr3,gr2
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movgs gr2,dcr
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LEDS 0x20fe,gr2
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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lddi.p @(gr31,#REG_GR(2)),gr2
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xor gr31,gr31,gr31
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movgs gr0,brr
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#ifdef CONFIG_MMU
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movsg scr3,gr31
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#endif
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rett #1
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#ifdef CONFIG_MMU
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# step through an ITLB-miss handler from user mode
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.globl __break_user_insn_tlb_miss
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__break_user_insn_tlb_miss:
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# we'll want to try the trap stub again
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sethi.p %hi(__trap_user_insn_tlb_miss),gr2
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setlo %lo(__trap_user_insn_tlb_miss),gr2
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movgs gr2,bpcsr
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__break_tlb_miss_common:
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LEDS 0x2101,gr2
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# cancel single-stepping mode
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movsg dcr,gr2
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sethi.p %hi(~DCR_SE),gr3
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setlo %lo(~DCR_SE),gr3
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and gr2,gr3,gr2
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movgs gr2,dcr
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# we'll swap the real return address for one with a BREAK insn so that we can re-enable
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# single stepping on return
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movsg pcsr,gr2
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sethi.p %hi(__break_tlb_miss_real_return_info),gr3
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setlo %lo(__break_tlb_miss_real_return_info),gr3
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sti gr2,@(gr3,#0)
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sethi.p %hi(__break_tlb_miss_return_break),gr2
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setlo %lo(__break_tlb_miss_return_break),gr2
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movgs gr2,pcsr
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# we also have to fudge PSR because the return BREAK is in kernel space and we want
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# to get a BREAK fault not an access violation should the return be to userspace
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movsg psr,gr2
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sti.p gr2,@(gr3,#4)
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ori gr2,#PSR_PS,gr2
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movgs gr2,psr
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LEDS 0x2102,gr2
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ldi @(gr31,#REG_CCR),gr3
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movgs gr3,ccr
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lddi @(gr31,#REG_GR(2)),gr2
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movsg scr3,gr31
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movgs gr0,brr
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rett #1
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# step through a DTLB-miss handler from user mode
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.globl __break_user_data_tlb_miss
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__break_user_data_tlb_miss:
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# we'll want to try the trap stub again
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sethi.p %hi(__trap_user_data_tlb_miss),gr2
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setlo %lo(__trap_user_data_tlb_miss),gr2
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movgs gr2,bpcsr
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bra __break_tlb_miss_common
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# step through an ITLB-miss handler from kernel mode
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.globl __break_kernel_insn_tlb_miss
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__break_kernel_insn_tlb_miss:
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# we'll want to try the trap stub again
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sethi.p %hi(__trap_kernel_insn_tlb_miss),gr2
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setlo %lo(__trap_kernel_insn_tlb_miss),gr2
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movgs gr2,bpcsr
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bra __break_tlb_miss_common
|
|
|
|
# step through a DTLB-miss handler from kernel mode
|
|
.globl __break_kernel_data_tlb_miss
|
|
__break_kernel_data_tlb_miss:
|
|
# we'll want to try the trap stub again
|
|
sethi.p %hi(__trap_kernel_data_tlb_miss),gr2
|
|
setlo %lo(__trap_kernel_data_tlb_miss),gr2
|
|
movgs gr2,bpcsr
|
|
bra __break_tlb_miss_common
|
|
#endif
|
|
|
|
###############################################################################
|
|
#
|
|
# handle debug events originating with userspace
|
|
#
|
|
###############################################################################
|
|
__break_maybe_userspace:
|
|
LEDS 0x3003,gr2
|
|
|
|
setlos #BPSR_BS,gr2
|
|
andcc gr3,gr2,gr0,icc0
|
|
bne icc0,#0,__break_continue /* skip if PSR.S was 1 */
|
|
|
|
movsg brr,gr2
|
|
andicc gr2,#BRR_ST|BRR_SB,gr0,icc0
|
|
beq icc0,#0,__break_continue /* jump if not BREAK or single-step */
|
|
|
|
LEDS 0x3007,gr2
|
|
|
|
# do the first part of the exception prologue here
|
|
sethi.p %hi(__kernel_frame0_ptr),gr28
|
|
setlo %lo(__kernel_frame0_ptr),gr28
|
|
ldi @(gr28,#0),gr28
|
|
andi gr28,#~7,gr28
|
|
|
|
# set up the kernel stack pointer
|
|
sti sp ,@(gr28,#REG_SP)
|
|
ori gr28,0,sp
|
|
sti gr0 ,@(gr28,#REG_GR(28))
|
|
|
|
stdi gr20,@(gr28,#REG_GR(20))
|
|
stdi gr22,@(gr28,#REG_GR(22))
|
|
|
|
movsg tbr,gr20
|
|
movsg bpcsr,gr21
|
|
movsg psr,gr22
|
|
|
|
# determine the exception type and cancel single-stepping mode
|
|
or gr0,gr0,gr23
|
|
|
|
movsg dcr,gr2
|
|
sethi.p %hi(DCR_SE),gr3
|
|
setlo %lo(DCR_SE),gr3
|
|
andcc gr2,gr3,gr0,icc0
|
|
beq icc0,#0,__break_no_user_sstep /* must have been a BREAK insn */
|
|
|
|
not gr3,gr3
|
|
and gr2,gr3,gr2
|
|
movgs gr2,dcr
|
|
ori gr23,#REG__STATUS_STEP,gr23
|
|
|
|
__break_no_user_sstep:
|
|
LEDS 0x300f,gr2
|
|
|
|
movsg brr,gr2
|
|
andi gr2,#BRR_ST|BRR_SB,gr2
|
|
slli gr2,#1,gr2
|
|
or gr23,gr2,gr23
|
|
sti.p gr23,@(gr28,#REG__STATUS) /* record single step status */
|
|
|
|
# adjust the value acquired from TBR - this indicates the exception
|
|
setlos #~TBR_TT,gr2
|
|
and.p gr20,gr2,gr20
|
|
setlos #TBR_TT_BREAK,gr2
|
|
or.p gr20,gr2,gr20
|
|
|
|
# fudge PSR.PS and BPSR.BS to return to kernel mode through the trap
|
|
# table as trap 126
|
|
andi gr22,#~PSR_PS,gr22 /* PSR.PS should be 0 */
|
|
movgs gr22,psr
|
|
|
|
setlos #BPSR_BS,gr2 /* BPSR.BS should be 1 and BPSR.BET 0 */
|
|
movgs gr2,bpsr
|
|
|
|
# return through remainder of the exception prologue
|
|
# - need to load gr23 with return handler address
|
|
sethi.p %hi(__entry_return_from_user_exception),gr23
|
|
setlo %lo(__entry_return_from_user_exception),gr23
|
|
sethi.p %hi(__entry_common),gr3
|
|
setlo %lo(__entry_common),gr3
|
|
movgs gr3,bpcsr
|
|
|
|
LEDS 0x301f,gr2
|
|
|
|
ldi @(gr31,#REG_CCR),gr3
|
|
movgs gr3,ccr
|
|
lddi.p @(gr31,#REG_GR(2)),gr2
|
|
xor gr31,gr31,gr31
|
|
movgs gr0,brr
|
|
#ifdef CONFIG_MMU
|
|
movsg scr3,gr31
|
|
#endif
|
|
rett #1
|
|
|
|
###############################################################################
|
|
#
|
|
# resume normal debug-mode entry
|
|
#
|
|
###############################################################################
|
|
__break_continue:
|
|
LEDS 0x4003,gr2
|
|
|
|
# set up the kernel stack pointer
|
|
sti sp,@(gr31,#REG_SP)
|
|
|
|
sethi.p %hi(__break_frame_0),sp
|
|
setlo %lo(__break_frame_0),sp
|
|
|
|
# finish building the exception frame
|
|
stdi gr4 ,@(gr31,#REG_GR(4))
|
|
stdi gr6 ,@(gr31,#REG_GR(6))
|
|
stdi gr8 ,@(gr31,#REG_GR(8))
|
|
stdi gr10,@(gr31,#REG_GR(10))
|
|
stdi gr12,@(gr31,#REG_GR(12))
|
|
stdi gr14,@(gr31,#REG_GR(14))
|
|
stdi gr16,@(gr31,#REG_GR(16))
|
|
stdi gr18,@(gr31,#REG_GR(18))
|
|
stdi gr20,@(gr31,#REG_GR(20))
|
|
stdi gr22,@(gr31,#REG_GR(22))
|
|
stdi gr24,@(gr31,#REG_GR(24))
|
|
stdi gr26,@(gr31,#REG_GR(26))
|
|
sti gr0 ,@(gr31,#REG_GR(28)) /* NULL frame pointer */
|
|
sti gr29,@(gr31,#REG_GR(29))
|
|
sti gr30,@(gr31,#REG_GR(30))
|
|
sti gr8 ,@(gr31,#REG_ORIG_GR8)
|
|
|
|
#ifdef CONFIG_MMU
|
|
movsg scr3,gr19
|
|
sti gr19,@(gr31,#REG_GR(31))
|
|
#endif
|
|
|
|
movsg bpsr ,gr19
|
|
movsg tbr ,gr20
|
|
movsg bpcsr,gr21
|
|
movsg psr ,gr22
|
|
movsg isr ,gr23
|
|
movsg cccr ,gr25
|
|
movsg lr ,gr26
|
|
movsg lcr ,gr27
|
|
|
|
andi.p gr22,#~(PSR_S|PSR_ET),gr5 /* rebuild PSR */
|
|
andi gr19,#PSR_ET,gr4
|
|
or.p gr4,gr5,gr5
|
|
srli gr19,#10,gr4
|
|
andi gr4,#PSR_S,gr4
|
|
or.p gr4,gr5,gr5
|
|
|
|
setlos #-1,gr6
|
|
sti gr20,@(gr31,#REG_TBR)
|
|
sti gr21,@(gr31,#REG_PC)
|
|
sti gr5 ,@(gr31,#REG_PSR)
|
|
sti gr23,@(gr31,#REG_ISR)
|
|
sti gr25,@(gr31,#REG_CCCR)
|
|
stdi gr26,@(gr31,#REG_LR)
|
|
sti gr6 ,@(gr31,#REG_SYSCALLNO)
|
|
|
|
# store CPU-specific regs
|
|
movsg iacc0h,gr4
|
|
movsg iacc0l,gr5
|
|
stdi gr4,@(gr31,#REG_IACC0)
|
|
|
|
movsg gner0,gr4
|
|
movsg gner1,gr5
|
|
stdi gr4,@(gr31,#REG_GNER0)
|
|
|
|
# build the debug register frame
|
|
movsg brr,gr4
|
|
movgs gr0,brr
|
|
movsg nmar,gr5
|
|
movsg dcr,gr6
|
|
|
|
sethi.p %hi(__debug_status),gr7
|
|
setlo %lo(__debug_status),gr7
|
|
|
|
stdi gr4 ,@(gr7,#DEBUG_BRR)
|
|
sti gr19,@(gr7,#DEBUG_BPSR)
|
|
sti.p gr6 ,@(gr7,#DEBUG_DCR)
|
|
|
|
# trap exceptions during break handling and disable h/w breakpoints/watchpoints
|
|
sethi %hi(DCR_EBE),gr5
|
|
setlo.p %lo(DCR_EBE),gr5
|
|
sethi %hi(__entry_breaktrap_table),gr4
|
|
setlo %lo(__entry_breaktrap_table),gr4
|
|
movgs gr5,dcr
|
|
movgs gr4,tbr
|
|
|
|
# set up kernel global registers
|
|
sethi.p %hi(__kernel_current_task),gr5
|
|
setlo %lo(__kernel_current_task),gr5
|
|
ld @(gr5,gr0),gr29
|
|
ldi.p @(gr29,#4),gr15 ; __current_thread_info = current->thread_info
|
|
|
|
sethi %hi(_gp),gr16
|
|
setlo.p %lo(_gp),gr16
|
|
|
|
# make sure we (the kernel) get div-zero and misalignment exceptions
|
|
setlos #ISR_EDE|ISR_DTT_DIVBYZERO|ISR_EMAM_EXCEPTION,gr5
|
|
movgs gr5,isr
|
|
|
|
# enter the GDB stub
|
|
LEDS 0x4007,gr2
|
|
|
|
or.p gr0,gr0,fp
|
|
call debug_stub
|
|
|
|
LEDS 0x403f,gr2
|
|
|
|
# return from break
|
|
lddi @(gr31,#REG_IACC0),gr4
|
|
movgs gr4,iacc0h
|
|
movgs gr5,iacc0l
|
|
|
|
lddi @(gr31,#REG_GNER0),gr4
|
|
movgs gr4,gner0
|
|
movgs gr5,gner1
|
|
|
|
lddi @(gr31,#REG_LR) ,gr26
|
|
lddi @(gr31,#REG_CCR) ,gr24
|
|
lddi @(gr31,#REG_PSR) ,gr22
|
|
ldi @(gr31,#REG_PC) ,gr21
|
|
ldi @(gr31,#REG_TBR) ,gr20
|
|
|
|
sethi.p %hi(__debug_status),gr6
|
|
setlo %lo(__debug_status),gr6
|
|
ldi.p @(gr6,#DEBUG_DCR) ,gr6
|
|
|
|
andi gr22,#PSR_S,gr19 /* rebuild BPSR */
|
|
andi.p gr22,#PSR_ET,gr5
|
|
slli gr19,#10,gr19
|
|
or gr5,gr19,gr19
|
|
|
|
movgs gr6 ,dcr
|
|
movgs gr19,bpsr
|
|
movgs gr20,tbr
|
|
movgs gr21,bpcsr
|
|
movgs gr23,isr
|
|
movgs gr24,ccr
|
|
movgs gr25,cccr
|
|
movgs gr26,lr
|
|
movgs gr27,lcr
|
|
|
|
LEDS 0x407f,gr2
|
|
|
|
#ifdef CONFIG_MMU
|
|
ldi @(gr31,#REG_GR(31)),gr2
|
|
movgs gr2,scr3
|
|
#endif
|
|
|
|
ldi @(gr31,#REG_GR(30)),gr30
|
|
ldi @(gr31,#REG_GR(29)),gr29
|
|
lddi @(gr31,#REG_GR(26)),gr26
|
|
lddi @(gr31,#REG_GR(24)),gr24
|
|
lddi @(gr31,#REG_GR(22)),gr22
|
|
lddi @(gr31,#REG_GR(20)),gr20
|
|
lddi @(gr31,#REG_GR(18)),gr18
|
|
lddi @(gr31,#REG_GR(16)),gr16
|
|
lddi @(gr31,#REG_GR(14)),gr14
|
|
lddi @(gr31,#REG_GR(12)),gr12
|
|
lddi @(gr31,#REG_GR(10)),gr10
|
|
lddi @(gr31,#REG_GR(8)) ,gr8
|
|
lddi @(gr31,#REG_GR(6)) ,gr6
|
|
lddi @(gr31,#REG_GR(4)) ,gr4
|
|
lddi @(gr31,#REG_GR(2)) ,gr2
|
|
ldi.p @(gr31,#REG_SP) ,sp
|
|
|
|
xor gr31,gr31,gr31
|
|
movgs gr0,brr
|
|
#ifdef CONFIG_MMU
|
|
movsg scr3,gr31
|
|
#endif
|
|
rett #1
|
|
|
|
###################################################################################################
|
|
#
|
|
# GDB stub "system calls"
|
|
#
|
|
###################################################################################################
|
|
|
|
#ifdef CONFIG_GDBSTUB
|
|
# void gdbstub_console_write(struct console *con, const char *p, unsigned n)
|
|
.globl gdbstub_console_write
|
|
gdbstub_console_write:
|
|
break
|
|
bralr
|
|
#endif
|
|
|
|
# GDB stub BUG() trap
|
|
# GR8 is the proposed signal number
|
|
.globl __debug_bug_trap
|
|
__debug_bug_trap:
|
|
break
|
|
bralr
|
|
|
|
# transfer kernel exeception to GDB for handling
|
|
.globl __break_hijack_kernel_event
|
|
__break_hijack_kernel_event:
|
|
break
|
|
.globl __break_hijack_kernel_event_breaks_here
|
|
__break_hijack_kernel_event_breaks_here:
|
|
nop
|
|
|
|
#ifdef CONFIG_MMU
|
|
# handle a return from TLB-miss that requires single-step reactivation
|
|
.globl __break_tlb_miss_return_break
|
|
__break_tlb_miss_return_break:
|
|
break
|
|
__break_tlb_miss_return_breaks_here:
|
|
nop
|
|
#endif
|
|
|
|
# guard the first .text label in the next file from confusion
|
|
nop
|