xref: /netbsd-src/sys/arch/arm/footbridge/footbridge_irqhandler.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /*	$NetBSD: footbridge_irqhandler.c,v 1.21 2008/04/27 18:58:44 matt Exp $	*/
2 
3 /*
4  * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project by
20  *	Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #ifndef ARM_SPL_NOINLINE
39 #define	ARM_SPL_NOINLINE
40 #endif
41 
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(0,"$NetBSD: footbridge_irqhandler.c,v 1.21 2008/04/27 18:58:44 matt Exp $");
44 
45 #include "opt_irqstats.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
50 #include <uvm/uvm_extern.h>
51 
52 #include <machine/intr.h>
53 #include <machine/cpu.h>
54 #include <arm/footbridge/dc21285mem.h>
55 #include <arm/footbridge/dc21285reg.h>
56 
57 #include <dev/pci/pcivar.h>
58 
59 #include "isa.h"
60 #if NISA > 0
61 #include <dev/isa/isavar.h>
62 #endif
63 
64 /* Interrupt handler queues. */
65 static struct intrq footbridge_intrq[NIRQ];
66 
67 /* Interrupts to mask at each level. */
68 int footbridge_imask[NIPL];
69 
70 /* Software copy of the IRQs we have enabled. */
71 volatile uint32_t intr_enabled;
72 
73 /* Interrupts pending */
74 volatile int footbridge_ipending;
75 
76 void footbridge_intr_dispatch(struct clockframe *frame);
77 
78 const struct evcnt *footbridge_pci_intr_evcnt(void *, pci_intr_handle_t);
79 
80 const struct evcnt *
81 footbridge_pci_intr_evcnt(void *pcv, pci_intr_handle_t ih)
82 {
83 	/* XXX check range is valid */
84 #if NISA > 0
85 	if (ih >= 0x80 && ih <= 0x8f) {
86 		return isa_intr_evcnt(NULL, (ih & 0x0f));
87 	}
88 #endif
89 	return &footbridge_intrq[ih].iq_ev;
90 }
91 
92 static inline void
93 footbridge_enable_irq(int irq)
94 {
95 	intr_enabled |= (1U << irq);
96 	footbridge_set_intrmask();
97 }
98 
99 static inline void
100 footbridge_disable_irq(int irq)
101 {
102 	intr_enabled &= ~(1U << irq);
103 	footbridge_set_intrmask();
104 }
105 
106 /*
107  * NOTE: This routine must be called with interrupts disabled in the CPSR.
108  */
109 static void
110 footbridge_intr_calculate_masks(void)
111 {
112 	struct intrq *iq;
113 	struct intrhand *ih;
114 	int irq, ipl;
115 
116 	/* First, figure out which IPLs each IRQ has. */
117 	for (irq = 0; irq < NIRQ; irq++) {
118 		int levels = 0;
119 		iq = &footbridge_intrq[irq];
120 		footbridge_disable_irq(irq);
121 		TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
122 			levels |= (1U << ih->ih_ipl);
123 		}
124 		iq->iq_levels = levels;
125 	}
126 
127 	/* Next, figure out which IRQs are used by each IPL. */
128 	for (ipl = 0; ipl < NIPL; ipl++) {
129 		int irqs = 0;
130 		for (irq = 0; irq < NIRQ; irq++) {
131 			if (footbridge_intrq[irq].iq_levels & (1U << ipl))
132 				irqs |= (1U << irq);
133 		}
134 		footbridge_imask[ipl] = irqs;
135 	}
136 
137 	/* IPL_NONE must open up all interrupts */
138 	KASSERT(footbridge_imask[IPL_NONE] == 0);
139 	KASSERT(footbridge_imask[IPL_SOFTCLOCK] == 0);
140 	KASSERT(footbridge_imask[IPL_SOFTBIO] == 0);
141 	KASSERT(footbridge_imask[IPL_SOFTNET] == 0);
142 	KASSERT(footbridge_imask[IPL_SOFTSERIAL] == 0);
143 
144 	/*
145 	 * Enforce a hierarchy that gives "slow" device (or devices with
146 	 * limited input buffer space/"real-time" requirements) a better
147 	 * chance at not dropping data.
148 	 */
149 	KASSERT(footbridge_imask[IPL_VM] != 0);
150 	footbridge_imask[IPL_SCHED] |= footbridge_imask[IPL_VM];
151 	footbridge_imask[IPL_HIGH] |= footbridge_imask[IPL_SCHED];
152 
153 	/*
154 	 * Calculate the ipl level to go to when handling this interrupt
155 	 */
156 	for (irq = 0, iq = footbridge_intrq; irq < NIRQ; irq++, iq++) {
157 		int irqs = (1U << irq);
158 		if (!TAILQ_EMPTY(&iq->iq_list)) {
159 			footbridge_enable_irq(irq);
160 			TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
161 				irqs |= footbridge_imask[ih->ih_ipl];
162 			}
163 		}
164 		iq->iq_mask = irqs;
165 	}
166 }
167 
168 int
169 _splraise(int ipl)
170 {
171     return (footbridge_splraise(ipl));
172 }
173 
174 /* this will always take us to the ipl passed in */
175 void
176 splx(int new)
177 {
178     footbridge_splx(new);
179 }
180 
181 int
182 _spllower(int ipl)
183 {
184     return (footbridge_spllower(ipl));
185 }
186 
187 void
188 footbridge_intr_init(void)
189 {
190 	struct intrq *iq;
191 	int i;
192 
193 	intr_enabled = 0;
194 	set_curcpl(0xffffffff);
195 	footbridge_ipending = 0;
196 	footbridge_set_intrmask();
197 
198 	for (i = 0, iq = footbridge_intrq; i < NIRQ; i++, iq++) {
199 		TAILQ_INIT(&iq->iq_list);
200 
201 		sprintf(iq->iq_name, "irq %d", i);
202 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
203 		    NULL, "footbridge", iq->iq_name);
204 	}
205 
206 	footbridge_intr_calculate_masks();
207 
208 	/* Enable IRQ's, we don't have any FIQ's*/
209 	enable_interrupts(I32_bit);
210 }
211 
212 void *
213 footbridge_intr_claim(int irq, int ipl, const char *name, int (*func)(void *), void *arg)
214 {
215 	struct intrq *iq;
216 	struct intrhand *ih;
217 	u_int oldirqstate;
218 
219 	if (irq < 0 || irq > NIRQ)
220 		panic("footbridge_intr_establish: IRQ %d out of range", irq);
221 
222 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
223 	if (ih == NULL)
224 	{
225 		printf("No memory");
226 		return (NULL);
227 	}
228 
229 	ih->ih_func = func;
230 	ih->ih_arg = arg;
231 	ih->ih_ipl = ipl;
232 	ih->ih_irq = irq;
233 
234 	iq = &footbridge_intrq[irq];
235 
236 	iq->iq_ist = IST_LEVEL;
237 
238 	oldirqstate = disable_interrupts(I32_bit);
239 
240 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
241 
242 	footbridge_intr_calculate_masks();
243 
244 	/* detach the existing event counter and add the new name */
245 	evcnt_detach(&iq->iq_ev);
246 	evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
247 			NULL, "footbridge", name);
248 
249 	restore_interrupts(oldirqstate);
250 
251 	return(ih);
252 }
253 
254 void
255 footbridge_intr_disestablish(void *cookie)
256 {
257 	struct intrhand *ih = cookie;
258 	struct intrq *iq = &footbridge_intrq[ih->ih_irq];
259 	int oldirqstate;
260 
261 	/* XXX need to free ih ? */
262 	oldirqstate = disable_interrupts(I32_bit);
263 
264 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
265 
266 	footbridge_intr_calculate_masks();
267 
268 	restore_interrupts(oldirqstate);
269 }
270 
271 static inline uint32_t footbridge_intstatus(void)
272 {
273 	return ((volatile uint32_t*)(DC21285_ARMCSR_VBASE))[IRQ_STATUS>>2];
274 }
275 
276 /* called with external interrupts disabled */
277 void
278 footbridge_intr_dispatch(struct clockframe *frame)
279 {
280 	struct intrq *iq;
281 	struct intrhand *ih;
282 	int oldirqstate, irq, ibit, hwpend;
283 	struct cpu_info * const ci = curcpu();
284 	const int ppl = ci->ci_cpl;
285 	const int imask = footbridge_imask[ppl];
286 
287 	hwpend = footbridge_intstatus();
288 
289 	/*
290 	 * Disable all the interrupts that are pending.  We will
291 	 * reenable them once they are processed and not masked.
292 	 */
293 	intr_enabled &= ~hwpend;
294 	footbridge_set_intrmask();
295 
296 	while (hwpend != 0) {
297 		int intr_rc = 0;
298 		irq = ffs(hwpend) - 1;
299 		ibit = (1U << irq);
300 
301 		hwpend &= ~ibit;
302 
303 		if (imask & ibit) {
304 			/*
305 			 * IRQ is masked; mark it as pending and check
306 			 * the next one.  Note: the IRQ is already disabled.
307 			 */
308 			footbridge_ipending |= ibit;
309 			continue;
310 		}
311 
312 		footbridge_ipending &= ~ibit;
313 
314 		iq = &footbridge_intrq[irq];
315 		iq->iq_ev.ev_count++;
316 		uvmexp.intrs++;
317 		TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
318 			ci->ci_cpl = ih->ih_ipl;
319 			oldirqstate = enable_interrupts(I32_bit);
320 			intr_rc = (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
321 			restore_interrupts(oldirqstate);
322 			if (intr_rc != 1)
323 				break;
324 		}
325 
326 		ci->ci_cpl = ppl;
327 
328 		/* Re-enable this interrupt now that's it's cleared. */
329 		intr_enabled |= ibit;
330 		footbridge_set_intrmask();
331 
332 		/* also check for any new interrupts that may have occurred,
333 		 * that we can handle at this spl level */
334 		hwpend |= (footbridge_ipending & ICU_INT_HWMASK) & ~imask;
335 	}
336 
337 #ifdef __HAVE_FAST_SOFTINTS
338 	cpu_dosoftints();
339 #endif /* __HAVE_FAST_SOFTINTS */
340 }
341