/arch/mips/sgi-ip22/ip22-int.c

  1/*
  2 * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
  3 *             found on INDY and Indigo2 workstations.
  4 *
  5 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
  6 * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
  7 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
  8 *                    - Indigo2 changes
  9 *                    - Interrupt handling fixes
 10 * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
 11 */
 12#include <linux/types.h>
 13#include <linux/init.h>
 14#include <linux/kernel_stat.h>
 15#include <linux/interrupt.h>
 16#include <linux/ftrace.h>
 17
 18#include <asm/irq_cpu.h>
 19#include <asm/sgi/hpc3.h>
 20#include <asm/sgi/ip22.h>
 21
 22/* So far nothing hangs here */
 23#undef USE_LIO3_IRQ
 24
 25struct sgint_regs *sgint;
 26
 27static char lc0msk_to_irqnr[256];
 28static char lc1msk_to_irqnr[256];
 29static char lc2msk_to_irqnr[256];
 30static char lc3msk_to_irqnr[256];
 31
 32extern int ip22_eisa_init(void);
 33
 34static void enable_local0_irq(unsigned int irq)
 35{
 36	/* don't allow mappable interrupt to be enabled from setup_irq,
 37	 * we have our own way to do so */
 38	if (irq != SGI_MAP_0_IRQ)
 39		sgint->imask0 |= (1 << (irq - SGINT_LOCAL0));
 40}
 41
 42static void disable_local0_irq(unsigned int irq)
 43{
 44	sgint->imask0 &= ~(1 << (irq - SGINT_LOCAL0));
 45}
 46
 47static struct irq_chip ip22_local0_irq_type = {
 48	.name		= "IP22 local 0",
 49	.ack		= disable_local0_irq,
 50	.mask		= disable_local0_irq,
 51	.mask_ack	= disable_local0_irq,
 52	.unmask		= enable_local0_irq,
 53};
 54
 55static void enable_local1_irq(unsigned int irq)
 56{
 57	/* don't allow mappable interrupt to be enabled from setup_irq,
 58	 * we have our own way to do so */
 59	if (irq != SGI_MAP_1_IRQ)
 60		sgint->imask1 |= (1 << (irq - SGINT_LOCAL1));
 61}
 62
 63static void disable_local1_irq(unsigned int irq)
 64{
 65	sgint->imask1 &= ~(1 << (irq - SGINT_LOCAL1));
 66}
 67
 68static struct irq_chip ip22_local1_irq_type = {
 69	.name		= "IP22 local 1",
 70	.ack		= disable_local1_irq,
 71	.mask		= disable_local1_irq,
 72	.mask_ack	= disable_local1_irq,
 73	.unmask		= enable_local1_irq,
 74};
 75
 76static void enable_local2_irq(unsigned int irq)
 77{
 78	sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
 79	sgint->cmeimask0 |= (1 << (irq - SGINT_LOCAL2));
 80}
 81
 82static void disable_local2_irq(unsigned int irq)
 83{
 84	sgint->cmeimask0 &= ~(1 << (irq - SGINT_LOCAL2));
 85	if (!sgint->cmeimask0)
 86		sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
 87}
 88
 89static struct irq_chip ip22_local2_irq_type = {
 90	.name		= "IP22 local 2",
 91	.ack		= disable_local2_irq,
 92	.mask		= disable_local2_irq,
 93	.mask_ack	= disable_local2_irq,
 94	.unmask		= enable_local2_irq,
 95};
 96
 97static void enable_local3_irq(unsigned int irq)
 98{
 99	sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
100	sgint->cmeimask1 |= (1 << (irq - SGINT_LOCAL3));
101}
102
103static void disable_local3_irq(unsigned int irq)
104{
105	sgint->cmeimask1 &= ~(1 << (irq - SGINT_LOCAL3));
106	if (!sgint->cmeimask1)
107		sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
108}
109
110static struct irq_chip ip22_local3_irq_type = {
111	.name		= "IP22 local 3",
112	.ack		= disable_local3_irq,
113	.mask		= disable_local3_irq,
114	.mask_ack	= disable_local3_irq,
115	.unmask		= enable_local3_irq,
116};
117
118static void indy_local0_irqdispatch(void)
119{
120	u8 mask = sgint->istat0 & sgint->imask0;
121	u8 mask2;
122	int irq;
123
124	if (mask & SGINT_ISTAT0_LIO2) {
125		mask2 = sgint->vmeistat & sgint->cmeimask0;
126		irq = lc2msk_to_irqnr[mask2];
127	} else
128		irq = lc0msk_to_irqnr[mask];
129
130	/* if irq == 0, then the interrupt has already been cleared */
131	if (irq)
132		do_IRQ(irq);
133}
134
135static void indy_local1_irqdispatch(void)
136{
137	u8 mask = sgint->istat1 & sgint->imask1;
138	u8 mask2;
139	int irq;
140
141	if (mask & SGINT_ISTAT1_LIO3) {
142		mask2 = sgint->vmeistat & sgint->cmeimask1;
143		irq = lc3msk_to_irqnr[mask2];
144	} else
145		irq = lc1msk_to_irqnr[mask];
146
147	/* if irq == 0, then the interrupt has already been cleared */
148	if (irq)
149		do_IRQ(irq);
150}
151
152extern void ip22_be_interrupt(int irq);
153
154static void __irq_entry indy_buserror_irq(void)
155{
156	int irq = SGI_BUSERR_IRQ;
157
158	irq_enter();
159	kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
160	ip22_be_interrupt(irq);
161	irq_exit();
162}
163
164static struct irqaction local0_cascade = {
165	.handler	= no_action,
166	.flags		= IRQF_DISABLED,
167	.name		= "local0 cascade",
168};
169
170static struct irqaction local1_cascade = {
171	.handler	= no_action,
172	.flags		= IRQF_DISABLED,
173	.name		= "local1 cascade",
174};
175
176static struct irqaction buserr = {
177	.handler	= no_action,
178	.flags		= IRQF_DISABLED,
179	.name		= "Bus Error",
180};
181
182static struct irqaction map0_cascade = {
183	.handler	= no_action,
184	.flags		= IRQF_DISABLED,
185	.name		= "mapable0 cascade",
186};
187
188#ifdef USE_LIO3_IRQ
189static struct irqaction map1_cascade = {
190	.handler	= no_action,
191	.flags		= IRQF_DISABLED,
192	.name		= "mapable1 cascade",
193};
194#define SGI_INTERRUPTS	SGINT_END
195#else
196#define SGI_INTERRUPTS	SGINT_LOCAL3
197#endif
198
199extern void indy_8254timer_irq(void);
200
201/*
202 * IRQs on the INDY look basically (barring software IRQs which we don't use
203 * at all) like:
204 *
205 *	MIPS IRQ	Source
206 *      --------        ------
207 *             0	Software (ignored)
208 *             1        Software (ignored)
209 *             2        Local IRQ level zero
210 *             3        Local IRQ level one
211 *             4        8254 Timer zero
212 *             5        8254 Timer one
213 *             6        Bus Error
214 *             7        R4k timer (what we use)
215 *
216 * We handle the IRQ according to _our_ priority which is:
217 *
218 * Highest ----     R4k Timer
219 *                  Local IRQ zero
220 *                  Local IRQ one
221 *                  Bus Error
222 *                  8254 Timer zero
223 * Lowest  ----     8254 Timer one
224 *
225 * then we just return, if multiple IRQs are pending then we will just take
226 * another exception, big deal.
227 */
228
229asmlinkage void plat_irq_dispatch(void)
230{
231	unsigned int pending = read_c0_status() & read_c0_cause();
232
233	/*
234	 * First we check for r4k counter/timer IRQ.
235	 */
236	if (pending & CAUSEF_IP7)
237		do_IRQ(SGI_TIMER_IRQ);
238	else if (pending & CAUSEF_IP2)
239		indy_local0_irqdispatch();
240	else if (pending & CAUSEF_IP3)
241		indy_local1_irqdispatch();
242	else if (pending & CAUSEF_IP6)
243		indy_buserror_irq();
244	else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
245		indy_8254timer_irq();
246}
247
248void __init arch_init_irq(void)
249{
250	int i;
251
252	/* Init local mask --> irq tables. */
253	for (i = 0; i < 256; i++) {
254		if (i & 0x80) {
255			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
256			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
257			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
258			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
259		} else if (i & 0x40) {
260			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
261			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
262			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
263			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
264		} else if (i & 0x20) {
265			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
266			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
267			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
268			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
269		} else if (i & 0x10) {
270			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
271			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
272			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
273			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
274		} else if (i & 0x08) {
275			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
276			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
277			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
278			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
279		} else if (i & 0x04) {
280			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
281			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
282			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
283			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
284		} else if (i & 0x02) {
285			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
286			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
287			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
288			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
289		} else if (i & 0x01) {
290			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
291			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
292			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
293			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
294		} else {
295			lc0msk_to_irqnr[i] = 0;
296			lc1msk_to_irqnr[i] = 0;
297			lc2msk_to_irqnr[i] = 0;
298			lc3msk_to_irqnr[i] = 0;
299		}
300	}
301
302	/* Mask out all interrupts. */
303	sgint->imask0 = 0;
304	sgint->imask1 = 0;
305	sgint->cmeimask0 = 0;
306	sgint->cmeimask1 = 0;
307
308	/* init CPU irqs */
309	mips_cpu_irq_init();
310
311	for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
312		struct irq_chip *handler;
313
314		if (i < SGINT_LOCAL1)
315			handler		= &ip22_local0_irq_type;
316		else if (i < SGINT_LOCAL2)
317			handler		= &ip22_local1_irq_type;
318		else if (i < SGINT_LOCAL3)
319			handler		= &ip22_local2_irq_type;
320		else
321			handler		= &ip22_local3_irq_type;
322
323		set_irq_chip_and_handler(i, handler, handle_level_irq);
324	}
325
326	/* vector handler. this register the IRQ as non-sharable */
327	setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade);
328	setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade);
329	setup_irq(SGI_BUSERR_IRQ, &buserr);
330
331	/* cascade in cascade. i love Indy ;-) */
332	setup_irq(SGI_MAP_0_IRQ, &map0_cascade);
333#ifdef USE_LIO3_IRQ
334	setup_irq(SGI_MAP_1_IRQ, &map1_cascade);
335#endif
336
337#ifdef CONFIG_EISA
338	if (ip22_is_fullhouse())	/* Only Indigo-2 has EISA stuff */
339		ip22_eisa_init();
340#endif
341}