1 /* $NetBSD: ep93xx_intr.c,v 1.28 2023/05/02 09:49:33 jmcneill Exp $ */
2 
3 /*
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jesse Off
9  *
10  * This code is derived from software contributed to The NetBSD Foundation
11  * by Ichiro FUKUHARA and Naoto Shimazaki.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: ep93xx_intr.c,v 1.28 2023/05/02 09:49:33 jmcneill Exp $");
37 
38 /*
39  * Interrupt support for the Cirrus Logic EP93XX
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kmem.h>
45 #include <sys/termios.h>
46 #include <sys/lwp.h>
47 
48 #include <sys/bus.h>
49 #include <sys/intr.h>
50 
51 #include <arm/locore.h>
52 
53 #include <arm/ep93xx/ep93xxreg.h>
54 #include <arm/ep93xx/ep93xxvar.h>
55 
56 /* Interrupt handler queues. */
57 struct intrq intrq[NIRQ];
58 
59 /* Interrupts to mask at each level. */
60 static uint32_t vic1_imask[NIPL];
61 static uint32_t vic2_imask[NIPL];
62 
63 /* Current interrupt priority level. */
64 volatile int hardware_spl_level;
65 
66 /* Software copy of the IRQs we have enabled. */
67 volatile uint32_t vic1_intr_enabled;
68 volatile uint32_t vic2_intr_enabled;
69 
70 void      ep93xx_intr_dispatch(struct trapframe *);
71 
72 #define VIC1REG(reg)          *((volatile uint32_t*) (EP93XX_AHB_VBASE + \
73           EP93XX_AHB_VIC1 + (reg)))
74 #define VIC2REG(reg)          *((volatile uint32_t*) (EP93XX_AHB_VBASE + \
75           EP93XX_AHB_VIC2 + (reg)))
76 
77 static void
ep93xx_set_intrmask(uint32_t vic1_irqs,uint32_t vic2_irqs)78 ep93xx_set_intrmask(uint32_t vic1_irqs, uint32_t vic2_irqs)
79 {
80           VIC1REG(EP93XX_VIC_IntEnClear) = vic1_irqs;
81           VIC1REG(EP93XX_VIC_IntEnable) = vic1_intr_enabled & ~vic1_irqs;
82           VIC2REG(EP93XX_VIC_IntEnClear) = vic2_irqs;
83           VIC2REG(EP93XX_VIC_IntEnable) = vic2_intr_enabled & ~vic2_irqs;
84 }
85 
86 static void
ep93xx_enable_irq(int irq)87 ep93xx_enable_irq(int irq)
88 {
89           if (irq < VIC_NIRQ) {
90                     vic1_intr_enabled |= (1U << irq);
91                     VIC1REG(EP93XX_VIC_IntEnable) = (1U << irq);
92           } else {
93                     vic2_intr_enabled |= (1U << (irq - VIC_NIRQ));
94                     VIC2REG(EP93XX_VIC_IntEnable) = (1U << (irq - VIC_NIRQ));
95           }
96 }
97 
98 static inline void
ep93xx_disable_irq(int irq)99 ep93xx_disable_irq(int irq)
100 {
101           if (irq < VIC_NIRQ) {
102                     vic1_intr_enabled &= ~(1U << irq);
103                     VIC1REG(EP93XX_VIC_IntEnClear) = (1U << irq);
104           } else {
105                     vic2_intr_enabled &= ~(1U << (irq - VIC_NIRQ));
106                     VIC2REG(EP93XX_VIC_IntEnClear) = (1U << (irq - VIC_NIRQ));
107           }
108 }
109 
110 /*
111  * NOTE: This routine must be called with interrupts disabled in the CPSR.
112  */
113 static void
ep93xx_intr_calculate_masks(void)114 ep93xx_intr_calculate_masks(void)
115 {
116           struct intrq *iq;
117           struct intrhand *ih;
118           int irq, ipl;
119 
120           /* First, figure out which IPLs each IRQ has. */
121           for (irq = 0; irq < NIRQ; irq++) {
122                     int levels = 0;
123                     iq = &intrq[irq];
124                     ep93xx_disable_irq(irq);
125                     for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
126                          ih = TAILQ_NEXT(ih, ih_list))
127                               levels |= (1U << ih->ih_ipl);
128                     iq->iq_levels = levels;
129           }
130 
131           /* Next, figure out which IRQs are used by each IPL. */
132           for (ipl = 0; ipl < NIPL; ipl++) {
133                     int vic1_irqs = 0;
134                     int vic2_irqs = 0;
135                     for (irq = 0; irq < VIC_NIRQ; irq++) {
136                               if (intrq[irq].iq_levels & (1U << ipl))
137                                         vic1_irqs |= (1U << irq);
138                     }
139                     vic1_imask[ipl] = vic1_irqs;
140                     for (irq = 0; irq < VIC_NIRQ; irq++) {
141                               if (intrq[irq + VIC_NIRQ].iq_levels & (1U << ipl))
142                                         vic2_irqs |= (1U << irq);
143                     }
144                     vic2_imask[ipl] = vic2_irqs;
145           }
146 
147           KASSERT(vic1_imask[IPL_NONE] == 0);
148           KASSERT(vic2_imask[IPL_NONE] == 0);
149           KASSERT(vic1_imask[IPL_SOFTCLOCK] == 0);
150           KASSERT(vic2_imask[IPL_SOFTCLOCK] == 0);
151           KASSERT(vic1_imask[IPL_SOFTBIO] == 0);
152           KASSERT(vic2_imask[IPL_SOFTBIO] == 0);
153           KASSERT(vic1_imask[IPL_SOFTNET] == 0);
154           KASSERT(vic2_imask[IPL_SOFTNET] == 0);
155           KASSERT(vic1_imask[IPL_SOFTSERIAL] == 0);
156           KASSERT(vic2_imask[IPL_SOFTSERIAL] == 0);
157 
158           /*
159            * splsched() must block anything that uses the scheduler.
160            */
161           vic1_imask[IPL_SCHED] |= vic1_imask[IPL_VM];
162           vic2_imask[IPL_SCHED] |= vic2_imask[IPL_VM];
163 
164           /*
165            * splhigh() must block "everything".
166            */
167           vic1_imask[IPL_HIGH] |= vic1_imask[IPL_SCHED];
168           vic2_imask[IPL_HIGH] |= vic2_imask[IPL_SCHED];
169 
170           /*
171            * Now compute which IRQs must be blocked when servicing any
172            * given IRQ.
173            */
174           for (irq = 0; irq < NIRQ; irq++) {
175                     int       vic1_irqs;
176                     int       vic2_irqs;
177 
178                     if (irq < VIC_NIRQ) {
179                               vic1_irqs = (1U << irq);
180                               vic2_irqs = 0;
181                     } else {
182                               vic1_irqs = 0;
183                               vic2_irqs = (1U << (irq - VIC_NIRQ));
184                     }
185                     iq = &intrq[irq];
186                     if (TAILQ_FIRST(&iq->iq_list) != NULL)
187                               ep93xx_enable_irq(irq);
188                     for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
189                          ih = TAILQ_NEXT(ih, ih_list)) {
190                               vic1_irqs |= vic1_imask[ih->ih_ipl];
191                               vic2_irqs |= vic2_imask[ih->ih_ipl];
192                     }
193                     iq->iq_vic1_mask = vic1_irqs;
194                     iq->iq_vic2_mask = vic2_irqs;
195           }
196 }
197 
198 inline void
splx(int new)199 splx(int new)
200 {
201           u_int     oldirqstate;
202 
203           oldirqstate = disable_interrupts(I32_bit);
204           set_curcpl(new);
205           if (new != hardware_spl_level) {
206                     hardware_spl_level = new;
207                     ep93xx_set_intrmask(vic1_imask[new], vic2_imask[new]);
208           }
209           restore_interrupts(oldirqstate);
210 
211 #ifdef __HAVE_FAST_SOFTINTS
212           cpu_dosoftints();
213 #endif
214 }
215 
216 int
_splraise(int ipl)217 _splraise(int ipl)
218 {
219           int       old;
220           u_int     oldirqstate;
221 
222           oldirqstate = disable_interrupts(I32_bit);
223           old = curcpl();
224           set_curcpl(ipl);
225           restore_interrupts(oldirqstate);
226           return (old);
227 }
228 
229 int
_spllower(int ipl)230 _spllower(int ipl)
231 {
232           int       old = curcpl();
233 
234           if (old <= ipl)
235                     return (old);
236           splx(ipl);
237           return (old);
238 }
239 
240 /*
241  * ep93xx_intr_init:
242  *
243  *        Initialize the rest of the interrupt subsystem, making it
244  *        ready to handle interrupts from devices.
245  */
246 void
ep93xx_intr_init(void)247 ep93xx_intr_init(void)
248 {
249           struct intrq *iq;
250           int i;
251 
252           vic1_intr_enabled = 0;
253           vic2_intr_enabled = 0;
254 
255           for (i = 0; i < NIRQ; i++) {
256                     iq = &intrq[i];
257                     TAILQ_INIT(&iq->iq_list);
258 
259                     snprintf(iq->iq_name, sizeof(iq->iq_name), "irq %d", i);
260           }
261           curcpu()->ci_intr_depth = 0;
262           set_curcpl(0);
263           hardware_spl_level = 0;
264 
265           /* All interrupts should use IRQ not FIQ */
266           VIC1REG(EP93XX_VIC_IntSelect) = 0;
267           VIC2REG(EP93XX_VIC_IntSelect) = 0;
268 
269           ep93xx_intr_calculate_masks();
270 
271           /* Enable IRQs (don't yet use FIQs). */
272           enable_interrupts(I32_bit);
273 }
274 
275 void
ep93xx_intr_evcnt_attach(void)276 ep93xx_intr_evcnt_attach(void)
277 {
278           struct intrq *iq;
279           int i;
280 
281           for (i = 0; i < NIRQ; i++) {
282                     iq = &intrq[i];
283                     evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
284                                              NULL, (i < VIC_NIRQ ? "vic1" : "vic2"),
285                                              iq->iq_name);
286           }
287 }
288 
289 void *
ep93xx_intr_establish(int irq,int ipl,int (* ih_func)(void *),void * arg)290 ep93xx_intr_establish(int irq, int ipl, int (*ih_func)(void *), void *arg)
291 {
292           struct intrq*                 iq;
293           struct intrhand*    ih;
294           u_int                         oldirqstate;
295 
296           if (irq < 0 || irq > NIRQ)
297                     panic("ep93xx_intr_establish: IRQ %d out of range", irq);
298           if (ipl < 0 || ipl > NIPL)
299                     panic("ep93xx_intr_establish: IPL %d out of range", ipl);
300 
301           ih = kmem_alloc(sizeof(*ih), KM_SLEEP);
302           ih->ih_func = ih_func;
303           ih->ih_arg = arg;
304           ih->ih_irq = irq;
305           ih->ih_ipl = ipl;
306 
307           iq = &intrq[irq];
308 
309           oldirqstate = disable_interrupts(I32_bit);
310           TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
311           ep93xx_intr_calculate_masks();
312           restore_interrupts(oldirqstate);
313 
314           return (ih);
315 }
316 
317 void
ep93xx_intr_disestablish(void * cookie)318 ep93xx_intr_disestablish(void *cookie)
319 {
320           struct intrhand*    ih = cookie;
321           struct intrq*                 iq = &intrq[ih->ih_irq];
322           u_int                         oldirqstate;
323 
324           oldirqstate = disable_interrupts(I32_bit);
325           TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
326           ep93xx_intr_calculate_masks();
327           restore_interrupts(oldirqstate);
328 
329           kmem_free(ih, sizeof(*ih));
330 }
331 
332 void
ep93xx_intr_dispatch(struct trapframe * frame)333 ep93xx_intr_dispatch(struct trapframe *frame)
334 {
335           struct intrq*                 iq;
336           struct intrhand*    ih;
337           u_int                         oldirqstate;
338           int                           pcpl;
339           uint32_t            vic1_hwpend;
340           uint32_t            vic2_hwpend;
341           int                           irq;
342 
343           pcpl = curcpl();
344 
345           vic1_hwpend = VIC1REG(EP93XX_VIC_IRQStatus);
346           vic2_hwpend = VIC2REG(EP93XX_VIC_IRQStatus);
347 
348           hardware_spl_level = pcpl;
349           ep93xx_set_intrmask(vic1_imask[pcpl] | vic1_hwpend,
350                                    vic2_imask[pcpl] | vic2_hwpend);
351 
352           vic1_hwpend &= ~vic1_imask[pcpl];
353           vic2_hwpend &= ~vic2_imask[pcpl];
354 
355           if (vic1_hwpend) {
356                     irq = ffs(vic1_hwpend) - 1;
357 
358                     iq = &intrq[irq];
359                     iq->iq_ev.ev_count++;
360                     curcpu()->ci_data.cpu_nintr++;
361                     TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
362                               set_curcpl(ih->ih_ipl);
363                               oldirqstate = enable_interrupts(I32_bit);
364                               (void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
365                               restore_interrupts(oldirqstate);
366                     }
367           } else if (vic2_hwpend) {
368                     irq = ffs(vic2_hwpend) - 1;
369 
370                     iq = &intrq[irq + VIC_NIRQ];
371                     iq->iq_ev.ev_count++;
372                     curcpu()->ci_data.cpu_nintr++;
373                     TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
374                               set_curcpl(ih->ih_ipl);
375                               oldirqstate = enable_interrupts(I32_bit);
376                               (void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
377                               restore_interrupts(oldirqstate);
378                     }
379           }
380 
381           set_curcpl(pcpl);
382           hardware_spl_level = pcpl;
383           ep93xx_set_intrmask(vic1_imask[pcpl], vic2_imask[pcpl]);
384 
385 #ifdef __HAVE_FAST_SOFTINTS
386           cpu_dosoftints();
387 #endif
388 }
389