• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  *	Macintosh interrupts
3  *
4  * General design:
5  * In contrary to the Amiga and Atari platforms, the Mac hardware seems to
6  * exclusively use the autovector interrupts (the 'generic level0-level7'
7  * interrupts with exception vectors 0x19-0x1f). The following interrupt levels
8  * are used:
9  *	1	- VIA1
10  *		  - slot 0: one second interrupt (CA2)
11  *		  - slot 1: VBlank (CA1)
12  *		  - slot 2: ADB data ready (SR full)
13  *		  - slot 3: ADB data  (CB2)
14  *		  - slot 4: ADB clock (CB1)
15  *		  - slot 5: timer 2
16  *		  - slot 6: timer 1
17  *		  - slot 7: status of IRQ; signals 'any enabled int.'
18  *
19  *	2	- VIA2 or RBV
20  *		  - slot 0: SCSI DRQ (CA2)
21  *		  - slot 1: NUBUS IRQ (CA1) need to read port A to find which
22  *		  - slot 2: /EXP IRQ (only on IIci)
23  *		  - slot 3: SCSI IRQ (CB2)
24  *		  - slot 4: ASC IRQ (CB1)
25  *		  - slot 5: timer 2 (not on IIci)
26  *		  - slot 6: timer 1 (not on IIci)
27  *		  - slot 7: status of IRQ; signals 'any enabled int.'
28  *
29  * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
30  *
31  *	3	- unused (?)
32  *
33  *	4	- SCC
34  *
35  *	5	- unused (?)
36  *		  [serial errors or special conditions seem to raise level 6
37  *		  interrupts on some models (LC4xx?)]
38  *
39  *	6	- off switch (?)
40  *
41  * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support
42  * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and
43  * sound out to their own autovector IRQs and gives VIA1 a higher priority:
44  *
45  *	1	- unused (?)
46  *
47  *	3	- on-board SONIC
48  *
49  *	5	- Apple Sound Chip (ASC)
50  *
51  *	6	- VIA1
52  *
53  * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to
54  * the Quadra (A/UX) mapping:
55  *
56  *	1	- ISM IOP (ADB)
57  *
58  *	2	- SCSI
59  *
60  *	3	- NuBus
61  *
62  *	4	- SCC IOP
63  *
64  *	6	- VIA1
65  *
66  * For PSC Macintoshes (660AV, 840AV):
67  *
68  *	3	- PSC level 3
69  *		  - slot 0: MACE
70  *
71  *	4	- PSC level 4
72  *		  - slot 1: SCC channel A interrupt
73  *		  - slot 2: SCC channel B interrupt
74  *		  - slot 3: MACE DMA
75  *
76  *	5	- PSC level 5
77  *
78  *	6	- PSC level 6
79  *
80  * Finally we have good 'ole level 7, the non-maskable interrupt:
81  *
82  *	7	- NMI (programmer's switch on the back of some Macs)
83  *		  Also RAM parity error on models which support it (IIc, IIfx?)
84  *
85  * The current interrupt logic looks something like this:
86  *
87  * - We install dispatchers for the autovector interrupts (1-7). These
88  *   dispatchers are responsible for querying the hardware (the
89  *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
90  *   this information a machspec interrupt number is generated by placing the
91  *   index of the interrupt hardware into the low three bits and the original
92  *   autovector interrupt number in the upper 5 bits. The handlers for the
93  *   resulting machspec interrupt are then called.
94  *
95  * - Nubus is a special case because its interrupts are hidden behind two
96  *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
97  *   which translates to IRQ number 17. In this spot we install _another_
98  *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
99  *   then forms a new machspec interrupt number as above with the slot number
100  *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
101  *   bits.  The handlers for this new machspec interrupt number are then
102  *   called. This puts Nubus interrupts into the range 56-62.
103  *
104  * - The Baboon interrupts (used on some PowerBooks) are an even more special
105  *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
106  *   third layer of indirection. Why oh why did the Apple engineers do that?
107  *
108  */
109 
110 #include <linux/types.h>
111 #include <linux/kernel.h>
112 #include <linux/sched.h>
113 #include <linux/interrupt.h>
114 #include <linux/irq.h>
115 #include <linux/delay.h>
116 
117 #include <asm/irq.h>
118 #include <asm/macintosh.h>
119 #include <asm/macints.h>
120 #include <asm/mac_via.h>
121 #include <asm/mac_psc.h>
122 #include <asm/mac_oss.h>
123 #include <asm/mac_iop.h>
124 #include <asm/mac_baboon.h>
125 #include <asm/hwtest.h>
126 #include <asm/irq_regs.h>
127 
128 #define SHUTUP_SONIC
129 
130 /*
131  * console_loglevel determines NMI handler function
132  */
133 
134 irqreturn_t mac_nmi_handler(int, void *);
135 irqreturn_t mac_debug_handler(int, void *);
136 
137 /* #define DEBUG_MACINTS */
138 
139 static unsigned int mac_irq_startup(struct irq_data *);
140 static void mac_irq_shutdown(struct irq_data *);
141 
142 static struct irq_chip mac_irq_chip = {
143 	.name		= "mac",
144 	.irq_enable	= mac_irq_enable,
145 	.irq_disable	= mac_irq_disable,
146 	.irq_startup	= mac_irq_startup,
147 	.irq_shutdown	= mac_irq_shutdown,
148 };
149 
mac_init_IRQ(void)150 void __init mac_init_IRQ(void)
151 {
152 #ifdef DEBUG_MACINTS
153 	printk("mac_init_IRQ(): Setting things up...\n");
154 #endif
155 	m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER,
156 				  NUM_MAC_SOURCES - IRQ_USER);
157 	/* Make sure the SONIC interrupt is cleared or things get ugly */
158 #ifdef SHUTUP_SONIC
159 	printk("Killing onboard sonic... ");
160 	/* This address should hopefully be mapped already */
161 	if (hwreg_present((void*)(0x50f0a000))) {
162 		*(long *)(0x50f0a014) = 0x7fffL;
163 		*(long *)(0x50f0a010) = 0L;
164 	}
165 	printk("Done.\n");
166 #endif /* SHUTUP_SONIC */
167 
168 	/*
169 	 * Now register the handlers for the master IRQ handlers
170 	 * at levels 1-7. Most of the work is done elsewhere.
171 	 */
172 
173 	if (oss_present)
174 		oss_register_interrupts();
175 	else
176 		via_register_interrupts();
177 	if (psc_present)
178 		psc_register_interrupts();
179 	if (baboon_present)
180 		baboon_register_interrupts();
181 	iop_register_interrupts();
182 	if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
183 			mac_nmi_handler))
184 		pr_err("Couldn't register NMI\n");
185 #ifdef DEBUG_MACINTS
186 	printk("mac_init_IRQ(): Done!\n");
187 #endif
188 }
189 
190 /*
191  *  mac_irq_enable - enable an interrupt source
192  * mac_irq_disable - disable an interrupt source
193  *
194  * These routines are just dispatchers to the VIA/OSS/PSC routines.
195  */
196 
mac_irq_enable(struct irq_data * data)197 void mac_irq_enable(struct irq_data *data)
198 {
199 	int irq = data->irq;
200 	int irq_src = IRQ_SRC(irq);
201 
202 	switch(irq_src) {
203 	case 1:
204 	case 2:
205 	case 7:
206 		if (oss_present)
207 			oss_irq_enable(irq);
208 		else
209 			via_irq_enable(irq);
210 		break;
211 	case 3:
212 	case 4:
213 	case 5:
214 	case 6:
215 		if (psc_present)
216 			psc_irq_enable(irq);
217 		else if (oss_present)
218 			oss_irq_enable(irq);
219 		break;
220 	case 8:
221 		if (baboon_present)
222 			baboon_irq_enable(irq);
223 		break;
224 	}
225 }
226 
mac_irq_disable(struct irq_data * data)227 void mac_irq_disable(struct irq_data *data)
228 {
229 	int irq = data->irq;
230 	int irq_src = IRQ_SRC(irq);
231 
232 	switch(irq_src) {
233 	case 1:
234 	case 2:
235 	case 7:
236 		if (oss_present)
237 			oss_irq_disable(irq);
238 		else
239 			via_irq_disable(irq);
240 		break;
241 	case 3:
242 	case 4:
243 	case 5:
244 	case 6:
245 		if (psc_present)
246 			psc_irq_disable(irq);
247 		else if (oss_present)
248 			oss_irq_disable(irq);
249 		break;
250 	case 8:
251 		if (baboon_present)
252 			baboon_irq_disable(irq);
253 		break;
254 	}
255 }
256 
mac_irq_startup(struct irq_data * data)257 static unsigned int mac_irq_startup(struct irq_data *data)
258 {
259 	int irq = data->irq;
260 
261 	if (IRQ_SRC(irq) == 7 && !oss_present)
262 		via_nubus_irq_startup(irq);
263 	else
264 		mac_irq_enable(data);
265 
266 	return 0;
267 }
268 
mac_irq_shutdown(struct irq_data * data)269 static void mac_irq_shutdown(struct irq_data *data)
270 {
271 	int irq = data->irq;
272 
273 	if (IRQ_SRC(irq) == 7 && !oss_present)
274 		via_nubus_irq_shutdown(irq);
275 	else
276 		mac_irq_disable(data);
277 }
278 
279 static int num_debug[8];
280 
mac_debug_handler(int irq,void * dev_id)281 irqreturn_t mac_debug_handler(int irq, void *dev_id)
282 {
283 	if (num_debug[irq] < 10) {
284 		printk("DEBUG: Unexpected IRQ %d\n", irq);
285 		num_debug[irq]++;
286 	}
287 	return IRQ_HANDLED;
288 }
289 
290 static int in_nmi;
291 static volatile int nmi_hold;
292 
mac_nmi_handler(int irq,void * dev_id)293 irqreturn_t mac_nmi_handler(int irq, void *dev_id)
294 {
295 	int i;
296 	/*
297 	 * generate debug output on NMI switch if 'debug' kernel option given
298 	 * (only works with Penguin!)
299 	 */
300 
301 	in_nmi++;
302 	for (i=0; i<100; i++)
303 		udelay(1000);
304 
305 	if (in_nmi == 1) {
306 		nmi_hold = 1;
307 		printk("... pausing, press NMI to resume ...");
308 	} else {
309 		printk(" ok!\n");
310 		nmi_hold = 0;
311 	}
312 
313 	barrier();
314 
315 	while (nmi_hold == 1)
316 		udelay(1000);
317 
318 	if (console_loglevel >= 8) {
319 #if 0
320 		struct pt_regs *fp = get_irq_regs();
321 		show_state();
322 		printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
323 		printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
324 		       fp->d0, fp->d1, fp->d2, fp->d3);
325 		printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
326 		       fp->d4, fp->d5, fp->a0, fp->a1);
327 
328 		if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
329 			printk("Corrupted stack page\n");
330 		printk("Process %s (pid: %d, stackpage=%08lx)\n",
331 			current->comm, current->pid, current->kernel_stack_page);
332 		if (intr_count == 1)
333 			dump_stack((struct frame *)fp);
334 #else
335 		/* printk("NMI "); */
336 #endif
337 	}
338 	in_nmi--;
339 	return IRQ_HANDLED;
340 }
341