xref: /openbmc/linux/arch/sparc/kernel/irq_32.c (revision d2168146)
1 /*
2  * Interrupt request handling routines. On the
3  * Sparc the IRQs are basically 'cast in stone'
4  * and you are supposed to probe the prom's device
5  * node trees to find out who's got which IRQ.
6  *
7  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
8  *  Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
9  *  Copyright (C) 1995,2002 Pete A. Zaitcev (zaitcev@yahoo.com)
10  *  Copyright (C) 1996 Dave Redman (djhr@tadpole.co.uk)
11  *  Copyright (C) 1998-2000 Anton Blanchard (anton@samba.org)
12  */
13 
14 #include <linux/kernel_stat.h>
15 #include <linux/seq_file.h>
16 #include <linux/export.h>
17 
18 #include <asm/cacheflush.h>
19 #include <asm/cpudata.h>
20 #include <asm/setup.h>
21 #include <asm/pcic.h>
22 #include <asm/leon.h>
23 
24 #include "kernel.h"
25 #include "irq.h"
26 
27 /* platform specific irq setup */
28 struct sparc_config sparc_config;
29 
30 unsigned long arch_local_irq_save(void)
31 {
32 	unsigned long retval;
33 	unsigned long tmp;
34 
35 	__asm__ __volatile__(
36 		"rd	%%psr, %0\n\t"
37 		"or	%0, %2, %1\n\t"
38 		"wr	%1, 0, %%psr\n\t"
39 		"nop; nop; nop\n"
40 		: "=&r" (retval), "=r" (tmp)
41 		: "i" (PSR_PIL)
42 		: "memory");
43 
44 	return retval;
45 }
46 EXPORT_SYMBOL(arch_local_irq_save);
47 
48 void arch_local_irq_enable(void)
49 {
50 	unsigned long tmp;
51 
52 	__asm__ __volatile__(
53 		"rd	%%psr, %0\n\t"
54 		"andn	%0, %1, %0\n\t"
55 		"wr	%0, 0, %%psr\n\t"
56 		"nop; nop; nop\n"
57 		: "=&r" (tmp)
58 		: "i" (PSR_PIL)
59 		: "memory");
60 }
61 EXPORT_SYMBOL(arch_local_irq_enable);
62 
63 void arch_local_irq_restore(unsigned long old_psr)
64 {
65 	unsigned long tmp;
66 
67 	__asm__ __volatile__(
68 		"rd	%%psr, %0\n\t"
69 		"and	%2, %1, %2\n\t"
70 		"andn	%0, %1, %0\n\t"
71 		"wr	%0, %2, %%psr\n\t"
72 		"nop; nop; nop\n"
73 		: "=&r" (tmp)
74 		: "i" (PSR_PIL), "r" (old_psr)
75 		: "memory");
76 }
77 EXPORT_SYMBOL(arch_local_irq_restore);
78 
79 /*
80  * Dave Redman (djhr@tadpole.co.uk)
81  *
82  * IRQ numbers.. These are no longer restricted to 15..
83  *
84  * this is done to enable SBUS cards and onboard IO to be masked
85  * correctly. using the interrupt level isn't good enough.
86  *
87  * For example:
88  *   A device interrupting at sbus level6 and the Floppy both come in
89  *   at IRQ11, but enabling and disabling them requires writing to
90  *   different bits in the SLAVIO/SEC.
91  *
92  * As a result of these changes sun4m machines could now support
93  * directed CPU interrupts using the existing enable/disable irq code
94  * with tweaks.
95  *
96  * Sun4d complicates things even further.  IRQ numbers are arbitrary
97  * 32-bit values in that case.  Since this is similar to sparc64,
98  * we adopt a virtual IRQ numbering scheme as is done there.
99  * Virutal interrupt numbers are allocated by build_irq().  So NR_IRQS
100  * just becomes a limit of how many interrupt sources we can handle in
101  * a single system.  Even fully loaded SS2000 machines top off at
102  * about 32 interrupt sources or so, therefore a NR_IRQS value of 64
103  * is more than enough.
104   *
105  * We keep a map of per-PIL enable interrupts.  These get wired
106  * up via the irq_chip->startup() method which gets invoked by
107  * the generic IRQ layer during request_irq().
108  */
109 
110 
111 /* Table of allocated irqs. Unused entries has irq == 0 */
112 static struct irq_bucket irq_table[NR_IRQS];
113 /* Protect access to irq_table */
114 static DEFINE_SPINLOCK(irq_table_lock);
115 
116 /* Map between the irq identifier used in hw to the irq_bucket. */
117 struct irq_bucket *irq_map[SUN4D_MAX_IRQ];
118 /* Protect access to irq_map */
119 static DEFINE_SPINLOCK(irq_map_lock);
120 
121 /* Allocate a new irq from the irq_table */
122 unsigned int irq_alloc(unsigned int real_irq, unsigned int pil)
123 {
124 	unsigned long flags;
125 	unsigned int i;
126 
127 	spin_lock_irqsave(&irq_table_lock, flags);
128 	for (i = 1; i < NR_IRQS; i++) {
129 		if (irq_table[i].real_irq == real_irq && irq_table[i].pil == pil)
130 			goto found;
131 	}
132 
133 	for (i = 1; i < NR_IRQS; i++) {
134 		if (!irq_table[i].irq)
135 			break;
136 	}
137 
138 	if (i < NR_IRQS) {
139 		irq_table[i].real_irq = real_irq;
140 		irq_table[i].irq = i;
141 		irq_table[i].pil = pil;
142 	} else {
143 		printk(KERN_ERR "IRQ: Out of virtual IRQs.\n");
144 		i = 0;
145 	}
146 found:
147 	spin_unlock_irqrestore(&irq_table_lock, flags);
148 
149 	return i;
150 }
151 
152 /* Based on a single pil handler_irq may need to call several
153  * interrupt handlers. Use irq_map as entry to irq_table,
154  * and let each entry in irq_table point to the next entry.
155  */
156 void irq_link(unsigned int irq)
157 {
158 	struct irq_bucket *p;
159 	unsigned long flags;
160 	unsigned int pil;
161 
162 	BUG_ON(irq >= NR_IRQS);
163 
164 	spin_lock_irqsave(&irq_map_lock, flags);
165 
166 	p = &irq_table[irq];
167 	pil = p->pil;
168 	BUG_ON(pil > SUN4D_MAX_IRQ);
169 	p->next = irq_map[pil];
170 	irq_map[pil] = p;
171 
172 	spin_unlock_irqrestore(&irq_map_lock, flags);
173 }
174 
175 void irq_unlink(unsigned int irq)
176 {
177 	struct irq_bucket *p, **pnext;
178 	unsigned long flags;
179 
180 	BUG_ON(irq >= NR_IRQS);
181 
182 	spin_lock_irqsave(&irq_map_lock, flags);
183 
184 	p = &irq_table[irq];
185 	BUG_ON(p->pil > SUN4D_MAX_IRQ);
186 	pnext = &irq_map[p->pil];
187 	while (*pnext != p)
188 		pnext = &(*pnext)->next;
189 	*pnext = p->next;
190 
191 	spin_unlock_irqrestore(&irq_map_lock, flags);
192 }
193 
194 
195 /* /proc/interrupts printing */
196 int arch_show_interrupts(struct seq_file *p, int prec)
197 {
198 	int j;
199 
200 #ifdef CONFIG_SMP
201 	seq_printf(p, "RES: ");
202 	for_each_online_cpu(j)
203 		seq_printf(p, "%10u ", cpu_data(j).irq_resched_count);
204 	seq_printf(p, "     IPI rescheduling interrupts\n");
205 	seq_printf(p, "CAL: ");
206 	for_each_online_cpu(j)
207 		seq_printf(p, "%10u ", cpu_data(j).irq_call_count);
208 	seq_printf(p, "     IPI function call interrupts\n");
209 #endif
210 	seq_printf(p, "NMI: ");
211 	for_each_online_cpu(j)
212 		seq_printf(p, "%10u ", cpu_data(j).counter);
213 	seq_printf(p, "     Non-maskable interrupts\n");
214 	return 0;
215 }
216 
217 void handler_irq(unsigned int pil, struct pt_regs *regs)
218 {
219 	struct pt_regs *old_regs;
220 	struct irq_bucket *p;
221 
222 	BUG_ON(pil > 15);
223 	old_regs = set_irq_regs(regs);
224 	irq_enter();
225 
226 	p = irq_map[pil];
227 	while (p) {
228 		struct irq_bucket *next = p->next;
229 
230 		generic_handle_irq(p->irq);
231 		p = next;
232 	}
233 	irq_exit();
234 	set_irq_regs(old_regs);
235 }
236 
237 #if defined(CONFIG_BLK_DEV_FD) || defined(CONFIG_BLK_DEV_FD_MODULE)
238 static unsigned int floppy_irq;
239 
240 int sparc_floppy_request_irq(unsigned int irq, irq_handler_t irq_handler)
241 {
242 	unsigned int cpu_irq;
243 	int err;
244 
245 
246 	err = request_irq(irq, irq_handler, 0, "floppy", NULL);
247 	if (err)
248 		return -1;
249 
250 	/* Save for later use in floppy interrupt handler */
251 	floppy_irq = irq;
252 
253 	cpu_irq = (irq & (NR_IRQS - 1));
254 
255 	/* Dork with trap table if we get this far. */
256 #define INSTANTIATE(table) \
257 	table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_one = SPARC_RD_PSR_L0; \
258 	table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two = \
259 		SPARC_BRANCH((unsigned long) floppy_hardint, \
260 			     (unsigned long) &table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two);\
261 	table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_three = SPARC_RD_WIM_L3; \
262 	table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_four = SPARC_NOP;
263 
264 	INSTANTIATE(sparc_ttable)
265 
266 #if defined CONFIG_SMP
267 	if (sparc_cpu_model != sparc_leon) {
268 		struct tt_entry *trap_table;
269 
270 		trap_table = &trapbase_cpu1;
271 		INSTANTIATE(trap_table)
272 		trap_table = &trapbase_cpu2;
273 		INSTANTIATE(trap_table)
274 		trap_table = &trapbase_cpu3;
275 		INSTANTIATE(trap_table)
276 	}
277 #endif
278 #undef INSTANTIATE
279 	/*
280 	 * XXX Correct thing whould be to flush only I- and D-cache lines
281 	 * which contain the handler in question. But as of time of the
282 	 * writing we have no CPU-neutral interface to fine-grained flushes.
283 	 */
284 	flush_cache_all();
285 	return 0;
286 }
287 EXPORT_SYMBOL(sparc_floppy_request_irq);
288 
289 /*
290  * These variables are used to access state from the assembler
291  * interrupt handler, floppy_hardint, so we cannot put these in
292  * the floppy driver image because that would not work in the
293  * modular case.
294  */
295 volatile unsigned char *fdc_status;
296 EXPORT_SYMBOL(fdc_status);
297 
298 char *pdma_vaddr;
299 EXPORT_SYMBOL(pdma_vaddr);
300 
301 unsigned long pdma_size;
302 EXPORT_SYMBOL(pdma_size);
303 
304 volatile int doing_pdma;
305 EXPORT_SYMBOL(doing_pdma);
306 
307 char *pdma_base;
308 EXPORT_SYMBOL(pdma_base);
309 
310 unsigned long pdma_areasize;
311 EXPORT_SYMBOL(pdma_areasize);
312 
313 /* Use the generic irq support to call floppy_interrupt
314  * which was setup using request_irq() in sparc_floppy_request_irq().
315  * We only have one floppy interrupt so we do not need to check
316  * for additional handlers being wired up by irq_link()
317  */
318 void sparc_floppy_irq(int irq, void *dev_id, struct pt_regs *regs)
319 {
320 	struct pt_regs *old_regs;
321 
322 	old_regs = set_irq_regs(regs);
323 	irq_enter();
324 	generic_handle_irq(floppy_irq);
325 	irq_exit();
326 	set_irq_regs(old_regs);
327 }
328 #endif
329 
330 /* djhr
331  * This could probably be made indirect too and assigned in the CPU
332  * bits of the code. That would be much nicer I think and would also
333  * fit in with the idea of being able to tune your kernel for your machine
334  * by removing unrequired machine and device support.
335  *
336  */
337 
338 void __init init_IRQ(void)
339 {
340 	switch (sparc_cpu_model) {
341 	case sun4m:
342 		pcic_probe();
343 		if (pcic_present())
344 			sun4m_pci_init_IRQ();
345 		else
346 			sun4m_init_IRQ();
347 		break;
348 
349 	case sun4d:
350 		sun4d_init_IRQ();
351 		break;
352 
353 	case sparc_leon:
354 		leon_init_IRQ();
355 		break;
356 
357 	default:
358 		prom_printf("Cannot initialize IRQs on this Sun machine...");
359 		break;
360 	}
361 }
362 
363