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1 | // SPDX-License-Identifier: GPL-2.0 | |
2 | /* | |
3 | * Macintosh interrupts | |
4 | * | |
5 | * General design: | |
6 | * In contrary to the Amiga and Atari platforms, the Mac hardware seems to | |
7 | * exclusively use the autovector interrupts (the 'generic level0-level7' | |
8 | * interrupts with exception vectors 0x19-0x1f). The following interrupt levels | |
9 | * are used: | |
10 | * 1 - VIA1 | |
11 | * - slot 0: one second interrupt (CA2) | |
12 | * - slot 1: VBlank (CA1) | |
13 | * - slot 2: ADB data ready (SR full) | |
14 | * - slot 3: ADB data (CB2) | |
15 | * - slot 4: ADB clock (CB1) | |
16 | * - slot 5: timer 2 | |
17 | * - slot 6: timer 1 | |
18 | * - slot 7: status of IRQ; signals 'any enabled int.' | |
19 | * | |
20 | * 2 - VIA2 or RBV | |
21 | * - slot 0: SCSI DRQ (CA2) | |
22 | * - slot 1: NUBUS IRQ (CA1) need to read port A to find which | |
23 | * - slot 2: /EXP IRQ (only on IIci) | |
24 | * - slot 3: SCSI IRQ (CB2) | |
25 | * - slot 4: ASC IRQ (CB1) | |
26 | * - slot 5: timer 2 (not on IIci) | |
27 | * - slot 6: timer 1 (not on IIci) | |
28 | * - slot 7: status of IRQ; signals 'any enabled int.' | |
29 | * | |
30 | * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes: | |
31 | * | |
32 | * 3 - unused (?) | |
33 | * | |
34 | * 4 - SCC | |
35 | * | |
36 | * 5 - unused (?) | |
37 | * [serial errors or special conditions seem to raise level 6 | |
38 | * interrupts on some models (LC4xx?)] | |
39 | * | |
40 | * 6 - off switch (?) | |
41 | * | |
42 | * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support | |
43 | * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and | |
44 | * sound out to their own autovector IRQs and gives VIA1 a higher priority: | |
45 | * | |
46 | * 1 - unused (?) | |
47 | * | |
48 | * 3 - on-board SONIC | |
49 | * | |
50 | * 5 - Apple Sound Chip (ASC) | |
51 | * | |
52 | * 6 - VIA1 | |
53 | * | |
54 | * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to | |
55 | * the Quadra (A/UX) mapping: | |
56 | * | |
57 | * 1 - ISM IOP (ADB) | |
58 | * | |
59 | * 2 - SCSI | |
60 | * | |
61 | * 3 - NuBus | |
62 | * | |
63 | * 4 - SCC IOP | |
64 | * | |
65 | * 6 - VIA1 | |
66 | * | |
67 | * For PSC Macintoshes (660AV, 840AV): | |
68 | * | |
69 | * 3 - PSC level 3 | |
70 | * - slot 0: MACE | |
71 | * | |
72 | * 4 - PSC level 4 | |
73 | * - slot 1: SCC channel A interrupt | |
74 | * - slot 2: SCC channel B interrupt | |
75 | * - slot 3: MACE DMA | |
76 | * | |
77 | * 5 - PSC level 5 | |
78 | * | |
79 | * 6 - PSC level 6 | |
80 | * | |
81 | * Finally we have good 'ole level 7, the non-maskable interrupt: | |
82 | * | |
83 | * 7 - NMI (programmer's switch on the back of some Macs) | |
84 | * Also RAM parity error on models which support it (IIc, IIfx?) | |
85 | * | |
86 | * The current interrupt logic looks something like this: | |
87 | * | |
88 | * - We install dispatchers for the autovector interrupts (1-7). These | |
89 | * dispatchers are responsible for querying the hardware (the | |
90 | * VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using | |
91 | * this information a machspec interrupt number is generated by placing the | |
92 | * index of the interrupt hardware into the low three bits and the original | |
93 | * autovector interrupt number in the upper 5 bits. The handlers for the | |
94 | * resulting machspec interrupt are then called. | |
95 | * | |
96 | * - Nubus is a special case because its interrupts are hidden behind two | |
97 | * layers of hardware. Nubus interrupts come in as index 1 on VIA #2, | |
98 | * which translates to IRQ number 17. In this spot we install _another_ | |
99 | * dispatcher. This dispatcher finds the interrupting slot number (9-F) and | |
100 | * then forms a new machspec interrupt number as above with the slot number | |
101 | * minus 9 in the low three bits and the pseudo-level 7 in the upper five | |
102 | * bits. The handlers for this new machspec interrupt number are then | |
103 | * called. This puts Nubus interrupts into the range 56-62. | |
104 | * | |
105 | * - The Baboon interrupts (used on some PowerBooks) are an even more special | |
106 | * case. They're hidden behind the Nubus slot $C interrupt thus adding a | |
107 | * third layer of indirection. Why oh why did the Apple engineers do that? | |
108 | * | |
109 | */ | |
110 | ||
111 | #include <linux/types.h> | |
112 | #include <linux/kernel.h> | |
113 | #include <linux/sched.h> | |
114 | #include <linux/sched/debug.h> | |
115 | #include <linux/interrupt.h> | |
116 | #include <linux/irq.h> | |
117 | #include <linux/delay.h> | |
118 | ||
119 | #include <asm/irq.h> | |
120 | #include <asm/macintosh.h> | |
121 | #include <asm/macints.h> | |
122 | #include <asm/mac_via.h> | |
123 | #include <asm/mac_psc.h> | |
124 | #include <asm/mac_oss.h> | |
125 | #include <asm/mac_iop.h> | |
126 | #include <asm/mac_baboon.h> | |
127 | #include <asm/hwtest.h> | |
128 | #include <asm/irq_regs.h> | |
129 | ||
130 | extern void show_registers(struct pt_regs *); | |
131 | ||
132 | irqreturn_t mac_nmi_handler(int, void *); | |
133 | ||
134 | static unsigned int mac_irq_startup(struct irq_data *); | |
135 | static void mac_irq_shutdown(struct irq_data *); | |
136 | ||
137 | static struct irq_chip mac_irq_chip = { | |
138 | .name = "mac", | |
139 | .irq_enable = mac_irq_enable, | |
140 | .irq_disable = mac_irq_disable, | |
141 | .irq_startup = mac_irq_startup, | |
142 | .irq_shutdown = mac_irq_shutdown, | |
143 | }; | |
144 | ||
145 | void __init mac_init_IRQ(void) | |
146 | { | |
147 | m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER, | |
148 | NUM_MAC_SOURCES - IRQ_USER); | |
149 | ||
150 | /* | |
151 | * Now register the handlers for the master IRQ handlers | |
152 | * at levels 1-7. Most of the work is done elsewhere. | |
153 | */ | |
154 | ||
155 | if (oss_present) | |
156 | oss_register_interrupts(); | |
157 | else | |
158 | via_register_interrupts(); | |
159 | if (psc) | |
160 | psc_register_interrupts(); | |
161 | if (baboon_present) | |
162 | baboon_register_interrupts(); | |
163 | iop_register_interrupts(); | |
164 | if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI", | |
165 | mac_nmi_handler)) | |
166 | pr_err("Couldn't register NMI\n"); | |
167 | } | |
168 | ||
169 | /* | |
170 | * mac_irq_enable - enable an interrupt source | |
171 | * mac_irq_disable - disable an interrupt source | |
172 | * | |
173 | * These routines are just dispatchers to the VIA/OSS/PSC routines. | |
174 | */ | |
175 | ||
176 | void mac_irq_enable(struct irq_data *data) | |
177 | { | |
178 | int irq = data->irq; | |
179 | int irq_src = IRQ_SRC(irq); | |
180 | ||
181 | switch(irq_src) { | |
182 | case 1: | |
183 | case 2: | |
184 | case 7: | |
185 | if (oss_present) | |
186 | oss_irq_enable(irq); | |
187 | else | |
188 | via_irq_enable(irq); | |
189 | break; | |
190 | case 3: | |
191 | case 4: | |
192 | case 5: | |
193 | case 6: | |
194 | if (psc) | |
195 | psc_irq_enable(irq); | |
196 | else if (oss_present) | |
197 | oss_irq_enable(irq); | |
198 | break; | |
199 | case 8: | |
200 | if (baboon_present) | |
201 | baboon_irq_enable(irq); | |
202 | break; | |
203 | } | |
204 | } | |
205 | ||
206 | void mac_irq_disable(struct irq_data *data) | |
207 | { | |
208 | int irq = data->irq; | |
209 | int irq_src = IRQ_SRC(irq); | |
210 | ||
211 | switch(irq_src) { | |
212 | case 1: | |
213 | case 2: | |
214 | case 7: | |
215 | if (oss_present) | |
216 | oss_irq_disable(irq); | |
217 | else | |
218 | via_irq_disable(irq); | |
219 | break; | |
220 | case 3: | |
221 | case 4: | |
222 | case 5: | |
223 | case 6: | |
224 | if (psc) | |
225 | psc_irq_disable(irq); | |
226 | else if (oss_present) | |
227 | oss_irq_disable(irq); | |
228 | break; | |
229 | case 8: | |
230 | if (baboon_present) | |
231 | baboon_irq_disable(irq); | |
232 | break; | |
233 | } | |
234 | } | |
235 | ||
236 | static unsigned int mac_irq_startup(struct irq_data *data) | |
237 | { | |
238 | int irq = data->irq; | |
239 | ||
240 | if (IRQ_SRC(irq) == 7 && !oss_present) | |
241 | via_nubus_irq_startup(irq); | |
242 | else | |
243 | mac_irq_enable(data); | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
248 | static void mac_irq_shutdown(struct irq_data *data) | |
249 | { | |
250 | int irq = data->irq; | |
251 | ||
252 | if (IRQ_SRC(irq) == 7 && !oss_present) | |
253 | via_nubus_irq_shutdown(irq); | |
254 | else | |
255 | mac_irq_disable(data); | |
256 | } | |
257 | ||
258 | static volatile int in_nmi; | |
259 | ||
260 | irqreturn_t mac_nmi_handler(int irq, void *dev_id) | |
261 | { | |
262 | if (in_nmi) | |
263 | return IRQ_HANDLED; | |
264 | in_nmi = 1; | |
265 | ||
266 | pr_info("Non-Maskable Interrupt\n"); | |
267 | show_registers(get_irq_regs()); | |
268 | ||
269 | in_nmi = 0; | |
270 | return IRQ_HANDLED; | |
271 | } |