i80200_irq.S revision 1.1 1 /* $NetBSD: i80200_irq.S,v 1.1 2002/01/24 01:12:40 thorpej 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
40 #include <machine/asm.h>
41 #include <machine/cpu.h>
42 #include <machine/frame.h>
43
44 #include <arm/xscale/i80200reg.h>
45
46 /*
47 * irq_entry:
48 *
49 * Main entry point for the IRQ vector.
50 *
51 * This function reads the 2 IQ80310 CPLD interrupt source
52 * registers, and then calls the installed handlers for each
53 * bit that is set. The function stray_irqhandler is called
54 * if a handler is not defined for a particular interrupt.
55 *
56 * If an interrupt handler is found, then it is called with
57 * r0 containing the argument defined in the handler structure.
58 * If the field ih_arg is zero, then a pointer to the IRQ frame
59 * on the stack is passed instead.
60 */
61
62 .text
63 .align 0
64
65 Lcurrent_intr_depth:
66 .word _C_LABEL(current_intr_depth)
67 .word _C_LABEL(prev_intr_depth)
68
69 Lintr_dispatch:
70 .word _C_LABEL(i80200_extirq_dispatch)
71
72 Lastpending:
73 .word _C_LABEL(astpending)
74
75 ASENTRY_NP(irq_entry)
76 sub lr, lr, #0x00000004 /* Adjust the lr */
77
78 PUSHFRAMEINSVC /* Push an interrupt frame */
79
80 /*
81 * Note that we have entered the IRQ handler. We are
82 * in SVC mode so we cannot use the processor mode to
83 * determine if we are in an IRQ. Instead, we will
84 * count each time the interrupt handler is nested.
85 */
86 ldr r0, Lcurrent_intr_depth
87 ldr r2, Lcurrent_intr_depth+4
88 ldr r1, [r0]
89 str r1, [r2]
90 add r1, r1, #1
91 str r1, [r0]
92
93 /*
94 * Get the interrupt status into a callee-save register.
95 */
96 mrc p13, 0, r4, c1, c0, 0
97
98 /*
99 * XXX Right here will be a good place to check for PMU
100 * XXX interrupts, if we decide to use IRQs for them.
101 */
102
103 /*
104 * Check for external IRQs. If we have one, call the
105 * external IRQ dispatcher. The argument is a pointer
106 * to the stack frame. This function will be called with
107 * interrupts disabled, and will return with interrupts
108 * disabled.
109 */
110 tst r4, #(INTSRC_II)
111 bne Lextirq_return /* no external IRQ pending */
112 ldr r1, Lintr_dispatch
113 add lr, pc, #Lextirq_return - . - 8
114 mov r0, sp
115 ldr pc, [r1]
116 Lextirq_return:
117
118 /* Decremement the nest count. */
119 ldr r0, Lcurrent_intr_depth
120 ldr r2, Lcurrent_intr_depth+4
121 ldr r1, [r0]
122 str r1, [r2]
123 sub r1, r1, #1
124 str r1, [r0]
125
126 /*
127 * If we're returning to user mode, check for pending ASTs.
128 */
129 ldr r0, [sp] /* Get the SPSR from stack */
130 and r0, r0, #(PSR_MODE) /* Test for USR32 mode before the IRQ */
131 teq r0, #(PSR_USR32_MODE)
132 bne Lirqout /* Nope, get out now */
133
134 Lastloop:
135 ldr r0, Lastpending /* Do we have an AST pending? */
136 ldr r1, [r0]
137 teq r1, #0x00000000
138 beq Lirqout /* Nope, get out now */
139
140 mov r1, #0x00000000
141 str r1, [r0] /* Clear astpending */
142
143 mrs r4, cpsr_all /* save CPSR */
144 bic r0, r4, #(I32_bit) /* Enable IRQs */
145 msr cpsr_all, r0
146
147 mov r0, sp
148 bl _C_LABEL(ast) /* ast(frame) */
149
150 msr cpsr_all, r4 /* Disable IRQs */
151 b Lastloop /* Check for more ASTs */
152
153 Lirqout:
154 PULLFRAMEFROMSVCANDEXIT
155 movs pc, lr /* Exit */
156
157 .bss
158 .align 0
159
160 .global _C_LABEL(astpending)
161 _C_LABEL(astpending):
162 .word 0
163
164 .global _C_LABEL(current_intr_depth)
165 _C_LABEL(current_intr_depth):
166 .word 0
167
168 .global _C_LABEL(prev_intr_depth)
169 _C_LABEL(prev_intr_depth):
170 .word 0
171
172 /*
173 * XXX Provide intrnames/intrcnt for legacy code, but
174 * don't actually use them.
175 */
176
177 .global _C_LABEL(intrnames), _C_LABEL(eintrnames)
178 .global _C_LABEL(intrcnt), _C_LABEL(eintrcnt)
179 _C_LABEL(intrnames):
180 _C_LABEL(eintrnames):
181
182 .global _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt)
183 _C_LABEL(intrcnt):
184 _C_LABEL(eintrcnt):
185