1 /*
2  * linux/arch/m68k/kernel/ints.c -- Linux/m68k general interrupt handling code
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file COPYING in the main directory of this archive
6  * for more details.
7  *
8  * 07/03/96: Timer initialization, and thus mach_sched_init(),
9  *           removed from request_irq() and moved to init_time().
10  *           We should therefore consider renaming our add_isr() and
11  *           remove_isr() to request_irq() and free_irq()
12  *           respectively, so they are compliant with the other
13  *           architectures.                                     /Jes
14  * 11/07/96: Changed all add_/remove_isr() to request_/free_irq() calls.
15  *           Removed irq list support, if any machine needs an irq server
16  *           it must implement this itself (as it's already done), instead
17  *           only default handler are used with mach_default_handler.
18  *           request_irq got some flags different from other architectures:
19  *           - IRQ_FLG_REPLACE : Replace an existing handler (the default one
20  *                               can be replaced without this flag)
21  *           - IRQ_FLG_LOCK : handler can't be replaced
22  *           There are other machine depending flags, see there
23  *           If you want to replace a default handler you should know what
24  *           you're doing, since it might handle different other irq sources
25  *           which must be served                               /Roman Zippel
26  */
27 
28 #include <linux/module.h>
29 #include <linux/types.h>
30 #include <linux/sched.h>
31 #include <linux/interrupt.h>
32 #include <linux/kernel_stat.h>
33 #include <linux/errno.h>
34 #include <linux/init.h>
35 
36 #include <asm/setup.h>
37 #include <asm/system.h>
38 #include <asm/irq.h>
39 #include <asm/traps.h>
40 #include <asm/page.h>
41 #include <asm/machdep.h>
42 #include <asm/cacheflush.h>
43 #include <asm/irq_regs.h>
44 
45 #ifdef CONFIG_Q40
46 #include <asm/q40ints.h>
47 #endif
48 
49 extern u32 auto_irqhandler_fixup[];
50 extern u32 user_irqhandler_fixup[];
51 extern u16 user_irqvec_fixup[];
52 
53 /* table for system interrupt handlers */
54 static struct irq_node *irq_list[NR_IRQS];
55 static struct irq_controller *irq_controller[NR_IRQS];
56 static int irq_depth[NR_IRQS];
57 
58 static int m68k_first_user_vec;
59 
60 static struct irq_controller auto_irq_controller = {
61 	.name		= "auto",
62 	.lock		= __SPIN_LOCK_UNLOCKED(auto_irq_controller.lock),
63 	.startup	= m68k_irq_startup,
64 	.shutdown	= m68k_irq_shutdown,
65 };
66 
67 static struct irq_controller user_irq_controller = {
68 	.name		= "user",
69 	.lock		= __SPIN_LOCK_UNLOCKED(user_irq_controller.lock),
70 	.startup	= m68k_irq_startup,
71 	.shutdown	= m68k_irq_shutdown,
72 };
73 
74 #define NUM_IRQ_NODES 100
75 static irq_node_t nodes[NUM_IRQ_NODES];
76 
77 /*
78  * void init_IRQ(void)
79  *
80  * Parameters:	None
81  *
82  * Returns:	Nothing
83  *
84  * This function should be called during kernel startup to initialize
85  * the IRQ handling routines.
86  */
87 
init_IRQ(void)88 void __init init_IRQ(void)
89 {
90 	int i;
91 
92 	/* assembly irq entry code relies on this... */
93 	if (HARDIRQ_MASK != 0x00ff0000) {
94 		extern void hardirq_mask_is_broken(void);
95 		hardirq_mask_is_broken();
96 	}
97 
98 	for (i = IRQ_AUTO_1; i <= IRQ_AUTO_7; i++)
99 		irq_controller[i] = &auto_irq_controller;
100 
101 	mach_init_IRQ();
102 }
103 
104 /**
105  * m68k_setup_auto_interrupt
106  * @handler: called from auto vector interrupts
107  *
108  * setup the handler to be called from auto vector interrupts instead of the
109  * standard __m68k_handle_int(), it will be called with irq numbers in the range
110  * from IRQ_AUTO_1 - IRQ_AUTO_7.
111  */
m68k_setup_auto_interrupt(void (* handler)(unsigned int,struct pt_regs *))112 void __init m68k_setup_auto_interrupt(void (*handler)(unsigned int, struct pt_regs *))
113 {
114 	if (handler)
115 		*auto_irqhandler_fixup = (u32)handler;
116 	flush_icache();
117 }
118 
119 /**
120  * m68k_setup_user_interrupt
121  * @vec: first user vector interrupt to handle
122  * @cnt: number of active user vector interrupts
123  * @handler: called from user vector interrupts
124  *
125  * setup user vector interrupts, this includes activating the specified range
126  * of interrupts, only then these interrupts can be requested (note: this is
127  * different from auto vector interrupts). An optional handler can be installed
128  * to be called instead of the default __m68k_handle_int(), it will be called
129  * with irq numbers starting from IRQ_USER.
130  */
m68k_setup_user_interrupt(unsigned int vec,unsigned int cnt,void (* handler)(unsigned int,struct pt_regs *))131 void __init m68k_setup_user_interrupt(unsigned int vec, unsigned int cnt,
132 				      void (*handler)(unsigned int, struct pt_regs *))
133 {
134 	int i;
135 
136 	BUG_ON(IRQ_USER + cnt > NR_IRQS);
137 	m68k_first_user_vec = vec;
138 	for (i = 0; i < cnt; i++)
139 		irq_controller[IRQ_USER + i] = &user_irq_controller;
140 	*user_irqvec_fixup = vec - IRQ_USER;
141 	if (handler)
142 		*user_irqhandler_fixup = (u32)handler;
143 	flush_icache();
144 }
145 
146 /**
147  * m68k_setup_irq_controller
148  * @contr: irq controller which controls specified irq
149  * @irq: first irq to be managed by the controller
150  *
151  * Change the controller for the specified range of irq, which will be used to
152  * manage these irq. auto/user irq already have a default controller, which can
153  * be changed as well, but the controller probably should use m68k_irq_startup/
154  * m68k_irq_shutdown.
155  */
m68k_setup_irq_controller(struct irq_controller * contr,unsigned int irq,unsigned int cnt)156 void m68k_setup_irq_controller(struct irq_controller *contr, unsigned int irq,
157 			       unsigned int cnt)
158 {
159 	int i;
160 
161 	for (i = 0; i < cnt; i++)
162 		irq_controller[irq + i] = contr;
163 }
164 
new_irq_node(void)165 irq_node_t *new_irq_node(void)
166 {
167 	irq_node_t *node;
168 	short i;
169 
170 	for (node = nodes, i = NUM_IRQ_NODES-1; i >= 0; node++, i--) {
171 		if (!node->handler) {
172 			memset(node, 0, sizeof(*node));
173 			return node;
174 		}
175 	}
176 
177 	printk ("new_irq_node: out of nodes\n");
178 	return NULL;
179 }
180 
setup_irq(unsigned int irq,struct irq_node * node)181 int setup_irq(unsigned int irq, struct irq_node *node)
182 {
183 	struct irq_controller *contr;
184 	struct irq_node **prev;
185 	unsigned long flags;
186 
187 	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
188 		printk("%s: Incorrect IRQ %d from %s\n",
189 		       __func__, irq, node->devname);
190 		return -ENXIO;
191 	}
192 
193 	spin_lock_irqsave(&contr->lock, flags);
194 
195 	prev = irq_list + irq;
196 	if (*prev) {
197 		/* Can't share interrupts unless both agree to */
198 		if (!((*prev)->flags & node->flags & IRQF_SHARED)) {
199 			spin_unlock_irqrestore(&contr->lock, flags);
200 			return -EBUSY;
201 		}
202 		while (*prev)
203 			prev = &(*prev)->next;
204 	}
205 
206 	if (!irq_list[irq]) {
207 		if (contr->startup)
208 			contr->startup(irq);
209 		else
210 			contr->enable(irq);
211 	}
212 	node->next = NULL;
213 	*prev = node;
214 
215 	spin_unlock_irqrestore(&contr->lock, flags);
216 
217 	return 0;
218 }
219 
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * devname,void * dev_id)220 int request_irq(unsigned int irq,
221 		irq_handler_t handler,
222 		unsigned long flags, const char *devname, void *dev_id)
223 {
224 	struct irq_node *node;
225 	int res;
226 
227 	node = new_irq_node();
228 	if (!node)
229 		return -ENOMEM;
230 
231 	node->handler = handler;
232 	node->flags   = flags;
233 	node->dev_id  = dev_id;
234 	node->devname = devname;
235 
236 	res = setup_irq(irq, node);
237 	if (res)
238 		node->handler = NULL;
239 
240 	return res;
241 }
242 
243 EXPORT_SYMBOL(request_irq);
244 
free_irq(unsigned int irq,void * dev_id)245 void free_irq(unsigned int irq, void *dev_id)
246 {
247 	struct irq_controller *contr;
248 	struct irq_node **p, *node;
249 	unsigned long flags;
250 
251 	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
252 		printk("%s: Incorrect IRQ %d\n", __func__, irq);
253 		return;
254 	}
255 
256 	spin_lock_irqsave(&contr->lock, flags);
257 
258 	p = irq_list + irq;
259 	while ((node = *p)) {
260 		if (node->dev_id == dev_id)
261 			break;
262 		p = &node->next;
263 	}
264 
265 	if (node) {
266 		*p = node->next;
267 		node->handler = NULL;
268 	} else
269 		printk("%s: Removing probably wrong IRQ %d\n",
270 		       __func__, irq);
271 
272 	if (!irq_list[irq]) {
273 		if (contr->shutdown)
274 			contr->shutdown(irq);
275 		else
276 			contr->disable(irq);
277 	}
278 
279 	spin_unlock_irqrestore(&contr->lock, flags);
280 }
281 
282 EXPORT_SYMBOL(free_irq);
283 
enable_irq(unsigned int irq)284 void enable_irq(unsigned int irq)
285 {
286 	struct irq_controller *contr;
287 	unsigned long flags;
288 
289 	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
290 		printk("%s: Incorrect IRQ %d\n",
291 		       __func__, irq);
292 		return;
293 	}
294 
295 	spin_lock_irqsave(&contr->lock, flags);
296 	if (irq_depth[irq]) {
297 		if (!--irq_depth[irq]) {
298 			if (contr->enable)
299 				contr->enable(irq);
300 		}
301 	} else
302 		WARN_ON(1);
303 	spin_unlock_irqrestore(&contr->lock, flags);
304 }
305 
306 EXPORT_SYMBOL(enable_irq);
307 
disable_irq(unsigned int irq)308 void disable_irq(unsigned int irq)
309 {
310 	struct irq_controller *contr;
311 	unsigned long flags;
312 
313 	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
314 		printk("%s: Incorrect IRQ %d\n",
315 		       __func__, irq);
316 		return;
317 	}
318 
319 	spin_lock_irqsave(&contr->lock, flags);
320 	if (!irq_depth[irq]++) {
321 		if (contr->disable)
322 			contr->disable(irq);
323 	}
324 	spin_unlock_irqrestore(&contr->lock, flags);
325 }
326 
327 EXPORT_SYMBOL(disable_irq);
328 
329 void disable_irq_nosync(unsigned int irq) __attribute__((alias("disable_irq")));
330 
331 EXPORT_SYMBOL(disable_irq_nosync);
332 
m68k_irq_startup(unsigned int irq)333 int m68k_irq_startup(unsigned int irq)
334 {
335 	if (irq <= IRQ_AUTO_7)
336 		vectors[VEC_SPUR + irq] = auto_inthandler;
337 	else
338 		vectors[m68k_first_user_vec + irq - IRQ_USER] = user_inthandler;
339 	return 0;
340 }
341 
m68k_irq_shutdown(unsigned int irq)342 void m68k_irq_shutdown(unsigned int irq)
343 {
344 	if (irq <= IRQ_AUTO_7)
345 		vectors[VEC_SPUR + irq] = bad_inthandler;
346 	else
347 		vectors[m68k_first_user_vec + irq - IRQ_USER] = bad_inthandler;
348 }
349 
350 
351 /*
352  * Do we need these probe functions on the m68k?
353  *
354  *  ... may be useful with ISA devices
355  */
probe_irq_on(void)356 unsigned long probe_irq_on (void)
357 {
358 #ifdef CONFIG_Q40
359 	if (MACH_IS_Q40)
360 		return q40_probe_irq_on();
361 #endif
362 	return 0;
363 }
364 
365 EXPORT_SYMBOL(probe_irq_on);
366 
probe_irq_off(unsigned long irqs)367 int probe_irq_off (unsigned long irqs)
368 {
369 #ifdef CONFIG_Q40
370 	if (MACH_IS_Q40)
371 		return q40_probe_irq_off(irqs);
372 #endif
373 	return 0;
374 }
375 
376 EXPORT_SYMBOL(probe_irq_off);
377 
irq_canonicalize(unsigned int irq)378 unsigned int irq_canonicalize(unsigned int irq)
379 {
380 #ifdef CONFIG_Q40
381 	if (MACH_IS_Q40 && irq == 11)
382 		irq = 10;
383 #endif
384 	return irq;
385 }
386 
387 EXPORT_SYMBOL(irq_canonicalize);
388 
m68k_handle_int(unsigned int irq)389 asmlinkage void m68k_handle_int(unsigned int irq)
390 {
391 	struct irq_node *node;
392 	kstat_cpu(0).irqs[irq]++;
393 	node = irq_list[irq];
394 	do {
395 		node->handler(irq, node->dev_id);
396 		node = node->next;
397 	} while (node);
398 }
399 
__m68k_handle_int(unsigned int irq,struct pt_regs * regs)400 asmlinkage void __m68k_handle_int(unsigned int irq, struct pt_regs *regs)
401 {
402 	struct pt_regs *old_regs;
403 	old_regs = set_irq_regs(regs);
404 	m68k_handle_int(irq);
405 	set_irq_regs(old_regs);
406 }
407 
handle_badint(struct pt_regs * regs)408 asmlinkage void handle_badint(struct pt_regs *regs)
409 {
410 	kstat_cpu(0).irqs[0]++;
411 	printk("unexpected interrupt from %u\n", regs->vector);
412 }
413 
show_interrupts(struct seq_file * p,void * v)414 int show_interrupts(struct seq_file *p, void *v)
415 {
416 	struct irq_controller *contr;
417 	struct irq_node *node;
418 	int i = *(loff_t *) v;
419 
420 	/* autovector interrupts */
421 	if (irq_list[i]) {
422 		contr = irq_controller[i];
423 		node = irq_list[i];
424 		seq_printf(p, "%-8s %3u: %10u %s", contr->name, i, kstat_cpu(0).irqs[i], node->devname);
425 		while ((node = node->next))
426 			seq_printf(p, ", %s", node->devname);
427 		seq_puts(p, "\n");
428 	}
429 	return 0;
430 }
431 
432 #ifdef CONFIG_PROC_FS
init_irq_proc(void)433 void init_irq_proc(void)
434 {
435 	/* Insert /proc/irq driver here */
436 }
437 #endif
438