entry-avr32b.s

linux 内核源代码

do_dtlb_modified:
	pushm	r0-r3
	mfsr	r1, SYSREG_TLBEAR
	mfsr	r0, SYSREG_PTBR
	lsr	r2, r1, PGDIR_SHIFT
	ld.w	r0, r0[r2 << 2]
	lsl	r1, (32 - PGDIR_SHIFT)
	lsr	r1, (32 - PGDIR_SHIFT) + PAGE_SHIFT

	/* Translate to virtual address in P1 */
	andl	r0, 0xf000
	sbr	r0, 31
	add	r2, r0, r1 << 2
	ld.w	r3, r2[0]
	sbr	r3, _PAGE_BIT_DIRTY
	mov	r0, r3
	st.w	r2[0], r3

	/* The page table is up-to-date. Update the TLB entry as well */
	andl	r0, lo(_PAGE_FLAGS_HARDWARE_MASK)
	mtsr	SYSREG_TLBELO, r0

	/* MMUCR[DRP] is updated automatically, so let's go... */
	tlbw

	popm	r0-r3
	rete

do_fpe_ll:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	unmask_interrupts
	mov	r12, 26
	mov	r11, sp
	rcall	do_fpe
	rjmp	ret_from_exception

ret_from_exception:
	mask_interrupts
	lddsp	r4, sp[REG_SR]

	andh	r4, (MODE_MASK >> 16), COH
	brne	fault_resume_kernel

	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_WORK_MASK, COH
	brne	fault_exit_work

fault_resume_user:
	popm	r8-r9
	mask_exceptions
	mtsr	SYSREG_RAR_EX, r8
	mtsr	SYSREG_RSR_EX, r9
	ldmts	sp++, r0-lr
	sub	sp, -4
	rete

fault_resume_kernel:
#ifdef CONFIG_PREEMPT
	get_thread_info	r0
	ld.w	r2, r0[TI_preempt_count]
	cp.w	r2, 0
	brne	1f
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_NEED_RESCHED
	brcc	1f
	lddsp	r4, sp[REG_SR]
	bld	r4, SYSREG_GM_OFFSET
	brcs	1f
	rcall	preempt_schedule_irq
1:
#endif

	popm	r8-r9
	mask_exceptions
	mfsr	r1, SYSREG_SR
	mtsr	SYSREG_RAR_EX, r8
	mtsr	SYSREG_RSR_EX, r9
	popm	lr
	sub	sp, -4		/* ignore SP */
	popm	r0-r12
	sub	sp, -4		/* ignore r12_orig */
	rete

irq_exit_work:
	/* Switch to exception mode so that we can share the same code. */
	mfsr	r8, SYSREG_SR
	cbr	r8, SYSREG_M0_OFFSET
	orh	r8, hi(SYSREG_BIT(M1) | SYSREG_BIT(M2))
	mtsr	SYSREG_SR, r8
	sub	pc, -2
	get_thread_info r0
	ld.w	r1, r0[TI_flags]

fault_exit_work:
	bld	r1, TIF_NEED_RESCHED
	brcc	1f
	unmask_interrupts
	rcall	schedule
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	fault_exit_work

1:	mov	r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
	tst	r1, r2
	breq	2f
	unmask_interrupts
	mov	r12, sp
	mov	r11, r0
	rcall	do_notify_resume
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	fault_exit_work

2:	bld	r1, TIF_BREAKPOINT
	brcc	fault_resume_user
	rjmp	enter_monitor_mode

	.section .kprobes.text, "ax", @progbits
	.type	handle_debug, @function
handle_debug:
	sub	sp, 4		/* r12_orig */
	stmts	--sp, r0-lr
	mfsr	r8, SYSREG_RAR_DBG
	mfsr	r9, SYSREG_RSR_DBG
	unmask_exceptions
	pushm	r8-r9
	bfextu	r9, r9, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	brne	debug_fixup_regs

.Ldebug_fixup_cont:
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_off
#endif
	mov	r12, sp
	rcall	do_debug
	mov	sp, r12

	lddsp	r2, sp[REG_SR]
	bfextu	r3, r2, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	brne	debug_resume_kernel

	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	mov	r2, _TIF_DBGWORK_MASK
	tst	r1, r2
	brne	debug_exit_work

	bld	r1, TIF_SINGLE_STEP
	brcc	1f
	mfdr	r4, OCD_DC
	sbr	r4, OCD_DC_SS_BIT
	mtdr	OCD_DC, r4

1:	popm	r10,r11
	mask_exceptions
	mtsr	SYSREG_RSR_DBG, r11
	mtsr	SYSREG_RAR_DBG, r10
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_on
1:
#endif
	ldmts	sp++, r0-lr
	sub	sp, -4
	retd
	.size	handle_debug, . - handle_debug

	/* Mode of the trapped context is in r9 */
	.type	debug_fixup_regs, @function
debug_fixup_regs:
	mfsr	r8, SYSREG_SR
	mov	r10, r8
	bfins	r8, r9, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	mtsr	SYSREG_SR, r8
	sub	pc, -2
	stdsp	sp[REG_LR], lr
	mtsr	SYSREG_SR, r10
	sub	pc, -2
	sub	r8, sp, -FRAME_SIZE_FULL
	stdsp	sp[REG_SP], r8
	rjmp	.Ldebug_fixup_cont
	.size	debug_fixup_regs, . - debug_fixup_regs

	.type	debug_resume_kernel, @function
debug_resume_kernel:
	mask_exceptions
	popm	r10, r11
	mtsr	SYSREG_RAR_DBG, r10
	mtsr	SYSREG_RSR_DBG, r11
#ifdef CONFIG_TRACE_IRQFLAGS
	bld	r11, SYSREG_GM_OFFSET
	brcc	1f
	rcall	trace_hardirqs_on
1:
#endif
	mfsr	r2, SYSREG_SR
	mov	r1, r2
	bfins	r2, r3, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	mtsr	SYSREG_SR, r2
	sub	pc, -2
	popm	lr
	mtsr	SYSREG_SR, r1
	sub	pc, -2
	sub	sp, -4		/* skip SP */
	popm	r0-r12
	sub	sp, -4
	retd
	.size	debug_resume_kernel, . - debug_resume_kernel

	.type	debug_exit_work, @function
debug_exit_work:
	/*
	 * We must return from Monitor Mode using a retd, and we must
	 * not schedule since that involves the D bit in SR getting
	 * cleared by something other than the debug hardware. This
	 * may cause undefined behaviour according to the Architecture
	 * manual.
	 *
	 * So we fix up the return address and status and return to a
	 * stub below in Exception mode. From there, we can follow the
	 * normal exception return path.
	 *
	 * The real return address and status registers are stored on
	 * the stack in the way the exception return path understands,
	 * so no need to fix anything up there.
	 */
	sub	r8, pc, . - fault_exit_work
	mtsr	SYSREG_RAR_DBG, r8
	mov	r9, 0
	orh	r9, hi(SR_EM | SR_GM | MODE_EXCEPTION)
	mtsr	SYSREG_RSR_DBG, r9
	sub	pc, -2
	retd
	.size	debug_exit_work, . - debug_exit_work

	.set	rsr_int0,	SYSREG_RSR_INT0
	.set	rsr_int1,	SYSREG_RSR_INT1
	.set	rsr_int2,	SYSREG_RSR_INT2
	.set	rsr_int3,	SYSREG_RSR_INT3
	.set	rar_int0,	SYSREG_RAR_INT0
	.set	rar_int1,	SYSREG_RAR_INT1
	.set	rar_int2,	SYSREG_RAR_INT2
	.set	rar_int3,	SYSREG_RAR_INT3

	.macro	IRQ_LEVEL level
	.type	irq_level\level, @function
irq_level\level:
	sub	sp, 4		/* r12_orig */
	stmts	--sp,r0-lr
	mfsr	r8, rar_int\level
	mfsr	r9, rsr_int\level

#ifdef CONFIG_PREEMPT
	sub	r11, pc, (. - system_call)
	cp.w	r11, r8
	breq	4f
#endif

	pushm	r8-r9

	mov	r11, sp
	mov	r12, \level

	rcall	do_IRQ

	lddsp	r4, sp[REG_SR]
	bfextu	r4, r4, SYSREG_M0_OFFSET, 3
	cp.w	r4, MODE_SUPERVISOR >> SYSREG_M0_OFFSET
	breq	2f
	cp.w	r4, MODE_USER >> SYSREG_M0_OFFSET
#ifdef CONFIG_PREEMPT
	brne	3f
#else
	brne	1f
#endif

	get_thread_info	r0
	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_WORK_MASK, COH
	brne	irq_exit_work

1:
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_on
#endif
	popm	r8-r9
	mtsr	rar_int\level, r8
	mtsr	rsr_int\level, r9
	ldmts	sp++,r0-lr
	sub	sp, -4		/* ignore r12_orig */
	rete

#ifdef CONFIG_PREEMPT
4:	mask_interrupts
	mfsr	r8, rsr_int\level
	sbr	r8, 16
	mtsr	rsr_int\level, r8
	ldmts	sp++, r0-lr
	sub	sp, -4		/* ignore r12_orig */
	rete
#endif

2:	get_thread_info	r0
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_CPU_GOING_TO_SLEEP
#ifdef CONFIG_PREEMPT
	brcc	3f
#else
	brcc	1b
#endif
	sub	r1, pc, . - cpu_idle_skip_sleep
	stdsp	sp[REG_PC], r1
#ifdef CONFIG_PREEMPT
3:	get_thread_info r0
	ld.w	r2, r0[TI_preempt_count]
	cp.w	r2, 0
	brne	1b
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_NEED_RESCHED
	brcc	1b
	lddsp	r4, sp[REG_SR]
	bld	r4, SYSREG_GM_OFFSET
	brcs	1b
	rcall	preempt_schedule_irq
#endif
	rjmp	1b
	.endm

	.section .irq.text,"ax",@progbits

.global cpu_idle_sleep
cpu_idle_sleep:
	mask_interrupts
	get_thread_info r8
	ld.w	r9, r8[TI_flags]
	bld	r9, TIF_NEED_RESCHED
	brcs	cpu_idle_enable_int_and_exit
	sbr	r9, TIF_CPU_GOING_TO_SLEEP
	st.w	r8[TI_flags], r9
	unmask_interrupts
	sleep 0
cpu_idle_skip_sleep:
	mask_interrupts
	ld.w	r9, r8[TI_flags]
	cbr	r9, TIF_CPU_GOING_TO_SLEEP
	st.w	r8[TI_flags], r9
cpu_idle_enable_int_and_exit:
	unmask_interrupts
	retal	r12

	.global	irq_level0
	.global	irq_level1
	.global	irq_level2
	.global	irq_level3
	IRQ_LEVEL 0
	IRQ_LEVEL 1
	IRQ_LEVEL 2
	IRQ_LEVEL 3

	.section .kprobes.text, "ax", @progbits
	.type	enter_monitor_mode, @function
enter_monitor_mode:
	/*
	 * We need to enter monitor mode to do a single step. The
	 * monitor code will alter the return address so that we
	 * return directly to the user instead of returning here.
	 */
	breakpoint
	rjmp	breakpoint_failed

	.size	enter_monitor_mode, . - enter_monitor_mode

	.type	debug_trampoline, @function
	.global	debug_trampoline
debug_trampoline:
	/*
	 * Save the registers on the stack so that the monitor code
	 * can find them easily.
	 */
	sub	sp, 4		/* r12_orig */
	stmts	--sp, r0-lr
	get_thread_info	r0
	ld.w	r8, r0[TI_rar_saved]
	ld.w	r9, r0[TI_rsr_saved]
	pushm	r8-r9

	/*
	 * The monitor code will alter the return address so we don't
	 * return here.
	 */
	breakpoint
	rjmp	breakpoint_failed
	.size	debug_trampoline, . - debug_trampoline

	.type breakpoint_failed, @function
breakpoint_failed:
	/*
	 * Something went wrong. Perhaps the debug hardware isn't
	 * enabled?
	 */
	lda.w	r12, msg_breakpoint_failed
	mov	r11, sp
	mov	r10, 9		/* SIGKILL */
	call	die
1:	rjmp	1b

msg_breakpoint_failed:
	.asciz	"Failed to enter Debug Mode"