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i80200_irq.S revision 1.8
      1 /*	$NetBSD: i80200_irq.S,v 1.8 2002/10/21 18:09:18 bjh21 Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 #include "assym.h"
     39 #include "opt_perfctrs.h"
     40 
     41 #include <machine/asm.h>
     42 #include <machine/cpu.h>
     43 #include <machine/frame.h>
     44 
     45 #include <arm/xscale/i80200reg.h>
     46 
     47 /*
     48  * irq_entry:
     49  *
     50  *	Main entry point for the IRQ vector on i80200 CPUs.  Calls
     51  *	board-specific external interrupt dispatch routine.
     52  */
     53 
     54 	.text
     55 	.align	0
     56 
     57 .Lcurrent_intr_depth:
     58 	.word	_C_LABEL(current_intr_depth)
     59 	.word	_C_LABEL(prev_intr_depth)
     60 
     61 .Lintr_dispatch:
     62 	.word	_C_LABEL(i80200_extirq_dispatch)
     63 
     64 #if defined(PERFCTRS)
     65 .Lpmc_dispatch:
     66 	.word	_C_LABEL(xscale_pmc_dispatch)
     67 #endif
     68 
     69 .Lastpending:
     70 	.word	_C_LABEL(astpending)
     71 
     72 ASENTRY_NP(irq_entry)
     73 	sub	lr, lr, #0x00000004	/* Adjust the lr */
     74 
     75 	PUSHFRAMEINSVC			/* Push an interrupt frame */
     76 
     77 	/*
     78 	 * Note that we have entered the IRQ handler.  We are
     79 	 * in SVC mode so we cannot use the processor mode to
     80 	 * determine if we are in an IRQ.  Instead, we will
     81 	 * count each time the interrupt handler is nested.
     82 	 */
     83 	ldr	r0, .Lcurrent_intr_depth
     84 	ldr	r2, .Lcurrent_intr_depth+4
     85 	ldr	r1, [r0]
     86 	str	r1, [r2]
     87 	add	r1, r1, #1
     88 	str	r1, [r0]
     89 
     90 	/*
     91 	 * Get the interrupt status into a callee-save register.
     92 	 */
     93 	mrc	p13, 0, r4, c4, c0, 0
     94 
     95 #if defined(PERFCTRS)
     96 	/*
     97 	 * Check for PMU interrupts.
     98 	 * If we have one, call the routine to handle it.
     99 	 */
    100 	tst	r4, #(INTSRC_PI)
    101 	beq	.Lpmc_intr_return
    102 	mov	r1, r4
    103 	mov	r0, sp
    104 	mov	lr, pc
    105 	ldr	pc, .Lpmc_dispatch
    106 #endif
    107 
    108 	/*
    109 	 * XXX - any need to handle BMU interrupts?
    110 	 */
    111 
    112 	/*
    113 	 * Check for external IRQs.  If we have one, call the
    114 	 * external IRQ dispatcher.  The argument is a pointer
    115 	 * to the stack frame.  This function will be called with
    116 	 * interrupts disabled, and will return with interrupts
    117 	 * disabled.
    118 	 */
    119 	tst	r4, #(INTSRC_II)
    120 	beq	.Lextirq_return		/* no external IRQ pending */
    121 	ldr	r1, .Lintr_dispatch
    122 	mov	r0, sp
    123 	mov	lr, pc
    124 	ldr	pc, [r1]
    125 .Lextirq_return:
    126 
    127 	/* Decremement the nest count. */
    128 	ldr	r0, .Lcurrent_intr_depth
    129 	ldr	r2, .Lcurrent_intr_depth+4
    130 	ldr	r1, [r0]
    131 	str	r1, [r2]
    132 	sub	r1, r1, #1
    133 	str	r1, [r0]
    134 
    135 	/*
    136 	 * If we're returning to user mode, check for pending ASTs.
    137 	 */
    138 	ldr	r0, [sp]		/* Get the SPSR from stack */
    139 	and	r0, r0, #(PSR_MODE)	/* Test for USR32 mode before the IRQ */
    140 	teq	r0, #(PSR_USR32_MODE)
    141 	bne	.Lirqout		/* Nope, get out now */
    142 
    143 .Lastloop:
    144 	ldr	r0, .Lastpending	/* Do we have an AST pending? */
    145 	ldr	r1, [r0]
    146 	teq	r1, #0x00000000
    147 	beq	.Lirqout		/* Nope, get out now */
    148 
    149 	mov	r1, #0x00000000
    150 	str	r1, [r0]		/* Clear astpending */
    151 
    152 	mrs	r4, cpsr		/* save CPSR */
    153 	bic	r0, r4, #(I32_bit)	/* Enable IRQs */
    154 	msr	cpsr_c, r0
    155 
    156 	mov	r0, sp
    157 	bl	_C_LABEL(ast)		/* ast(frame) */
    158 
    159 	msr	cpsr_c, r4		/* Disable IRQs */
    160 	b	.Lastloop		/* Check for more ASTs */
    161 
    162 .Lirqout:
    163 	PULLFRAMEFROMSVCANDEXIT
    164 	movs	pc, lr			/* Exit */
    165 
    166 	.bss
    167 	.align	0
    168 
    169 	.global _C_LABEL(astpending)
    170 _C_LABEL(astpending):
    171 	.word	0
    172 
    173 	.global	_C_LABEL(current_intr_depth)
    174 _C_LABEL(current_intr_depth):
    175 	.word	0
    176 
    177 	.global	_C_LABEL(prev_intr_depth)
    178 _C_LABEL(prev_intr_depth):
    179 	.word	0
    180 
    181 	/*
    182 	 * XXX Provide intrnames/intrcnt for legacy code, but
    183 	 * don't actually use them.
    184 	 */
    185 
    186 	.global _C_LABEL(intrnames), _C_LABEL(eintrnames)
    187 	.global _C_LABEL(intrcnt), _C_LABEL(eintrcnt)
    188 _C_LABEL(intrnames):
    189 _C_LABEL(eintrnames):
    190 
    191 	.global _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt)
    192 _C_LABEL(intrcnt):
    193 _C_LABEL(eintrcnt):
    194