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ep93xx_intr.c revision 1.18
      1 /* $NetBSD: ep93xx_intr.c,v 1.18 2012/11/12 18:00:36 skrll 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 1.18 2012/11/12 18:00:36 skrll 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/malloc.h>
     45 #include <sys/termios.h>
     46 
     47 #include <sys/bus.h>
     48 #include <machine/intr.h>
     49 
     50 #include <arm/cpufunc.h>
     51 
     52 #include <arm/ep93xx/ep93xxreg.h>
     53 #include <arm/ep93xx/ep93xxvar.h>
     54 
     55 /* Interrupt handler queues. */
     56 struct intrq intrq[NIRQ];
     57 
     58 /* Interrupts to mask at each level. */
     59 static uint32_t vic1_imask[NIPL];
     60 static uint32_t vic2_imask[NIPL];
     61 
     62 /* Current interrupt priority level. */
     63 volatile int hardware_spl_level;
     64 
     65 /* Software copy of the IRQs we have enabled. */
     66 volatile uint32_t vic1_intr_enabled;
     67 volatile uint32_t vic2_intr_enabled;
     68 
     69 /* Interrupts pending. */
     70 static volatile int ipending;
     71 
     72 void	ep93xx_intr_dispatch(struct trapframe *);
     73 
     74 #define VIC1REG(reg)	*((volatile uint32_t*) (EP93XX_AHB_VBASE + \
     75 	EP93XX_AHB_VIC1 + (reg)))
     76 #define VIC2REG(reg)	*((volatile uint32_t*) (EP93XX_AHB_VBASE + \
     77 	EP93XX_AHB_VIC2 + (reg)))
     78 
     79 static void
     80 ep93xx_set_intrmask(uint32_t vic1_irqs, uint32_t vic2_irqs)
     81 {
     82 	VIC1REG(EP93XX_VIC_IntEnClear) = vic1_irqs;
     83 	VIC1REG(EP93XX_VIC_IntEnable) = vic1_intr_enabled & ~vic1_irqs;
     84 	VIC2REG(EP93XX_VIC_IntEnClear) = vic2_irqs;
     85 	VIC2REG(EP93XX_VIC_IntEnable) = vic2_intr_enabled & ~vic2_irqs;
     86 }
     87 
     88 static void
     89 ep93xx_enable_irq(int irq)
     90 {
     91 	if (irq < VIC_NIRQ) {
     92 		vic1_intr_enabled |= (1U << irq);
     93 		VIC1REG(EP93XX_VIC_IntEnable) = (1U << irq);
     94 	} else {
     95 		vic2_intr_enabled |= (1U << (irq - VIC_NIRQ));
     96 		VIC2REG(EP93XX_VIC_IntEnable) = (1U << (irq - VIC_NIRQ));
     97 	}
     98 }
     99 
    100 static inline void
    101 ep93xx_disable_irq(int irq)
    102 {
    103 	if (irq < VIC_NIRQ) {
    104 		vic1_intr_enabled &= ~(1U << irq);
    105 		VIC1REG(EP93XX_VIC_IntEnClear) = (1U << irq);
    106 	} else {
    107 		vic2_intr_enabled &= ~(1U << (irq - VIC_NIRQ));
    108 		VIC2REG(EP93XX_VIC_IntEnClear) = (1U << (irq - VIC_NIRQ));
    109 	}
    110 }
    111 
    112 /*
    113  * NOTE: This routine must be called with interrupts disabled in the CPSR.
    114  */
    115 static void
    116 ep93xx_intr_calculate_masks(void)
    117 {
    118 	struct intrq *iq;
    119 	struct intrhand *ih;
    120 	int irq, ipl;
    121 
    122 	/* First, figure out which IPLs each IRQ has. */
    123 	for (irq = 0; irq < NIRQ; irq++) {
    124 		int levels = 0;
    125 		iq = &intrq[irq];
    126 		ep93xx_disable_irq(irq);
    127 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    128 		     ih = TAILQ_NEXT(ih, ih_list))
    129 			levels |= (1U << ih->ih_ipl);
    130 		iq->iq_levels = levels;
    131 	}
    132 
    133 	/* Next, figure out which IRQs are used by each IPL. */
    134 	for (ipl = 0; ipl < NIPL; ipl++) {
    135 		int vic1_irqs = 0;
    136 		int vic2_irqs = 0;
    137 		for (irq = 0; irq < VIC_NIRQ; irq++) {
    138 			if (intrq[irq].iq_levels & (1U << ipl))
    139 				vic1_irqs |= (1U << irq);
    140 		}
    141 		vic1_imask[ipl] = vic1_irqs;
    142 		for (irq = 0; irq < VIC_NIRQ; irq++) {
    143 			if (intrq[irq + VIC_NIRQ].iq_levels & (1U << ipl))
    144 				vic2_irqs |= (1U << irq);
    145 		}
    146 		vic2_imask[ipl] = vic2_irqs;
    147 	}
    148 
    149 	KASSERT(vic1_imask[IPL_NONE] == 0);
    150 	KASSERT(vic2_imask[IPL_NONE] == 0);
    151 	KASSERT(vic1_imask[IPL_SOFTCLOCK] == 0);
    152 	KASSERT(vic2_imask[IPL_SOFTCLOCK] == 0);
    153 	KASSERT(vic1_imask[IPL_SOFTBIO] == 0);
    154 	KASSERT(vic2_imask[IPL_SOFTBIO] == 0);
    155 	KASSERT(vic1_imask[IPL_SOFTNET] == 0);
    156 	KASSERT(vic2_imask[IPL_SOFTNET] == 0);
    157 	KASSERT(vic1_imask[IPL_SOFTSERIAL] == 0);
    158 	KASSERT(vic2_imask[IPL_SOFTSERIAL] == 0);
    159 
    160 	/*
    161 	 * splsched() must block anything that uses the scheduler.
    162 	 */
    163 	vic1_imask[IPL_SCHED] |= vic1_imask[IPL_VM];
    164 	vic2_imask[IPL_SCHED] |= vic2_imask[IPL_VM];
    165 
    166 	/*
    167 	 * splhigh() must block "everything".
    168 	 */
    169 	vic1_imask[IPL_HIGH] |= vic1_imask[IPL_SCHED];
    170 	vic2_imask[IPL_HIGH] |= vic2_imask[IPL_SCHED];
    171 
    172 	/*
    173 	 * Now compute which IRQs must be blocked when servicing any
    174 	 * given IRQ.
    175 	 */
    176 	for (irq = 0; irq < NIRQ; irq++) {
    177 		int	vic1_irqs;
    178 		int	vic2_irqs;
    179 
    180 		if (irq < VIC_NIRQ) {
    181 			vic1_irqs = (1U << irq);
    182 			vic2_irqs = 0;
    183 		} else {
    184 			vic1_irqs = 0;
    185 			vic2_irqs = (1U << (irq - VIC_NIRQ));
    186 		}
    187 		iq = &intrq[irq];
    188 		if (TAILQ_FIRST(&iq->iq_list) != NULL)
    189 			ep93xx_enable_irq(irq);
    190 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    191 		     ih = TAILQ_NEXT(ih, ih_list)) {
    192 			vic1_irqs |= vic1_imask[ih->ih_ipl];
    193 			vic2_irqs |= vic2_imask[ih->ih_ipl];
    194 		}
    195 		iq->iq_vic1_mask = vic1_irqs;
    196 		iq->iq_vic2_mask = vic2_irqs;
    197 	}
    198 }
    199 
    200 inline void
    201 splx(int new)
    202 {
    203 	int	old;
    204 	u_int	oldirqstate;
    205 
    206 	oldirqstate = disable_interrupts(I32_bit);
    207 	old = curcpl();
    208 	set_curcpl(new);
    209 	if (new != hardware_spl_level) {
    210 		hardware_spl_level = new;
    211 		ep93xx_set_intrmask(vic1_imask[new], vic2_imask[new]);
    212 	}
    213 	restore_interrupts(oldirqstate);
    214 
    215 #ifdef __HAVE_FAST_SOFTINTS
    216 	cpu_dosoftints();
    217 #endif
    218 }
    219 
    220 int
    221 _splraise(int ipl)
    222 {
    223 	int	old;
    224 	u_int	oldirqstate;
    225 
    226 	oldirqstate = disable_interrupts(I32_bit);
    227 	old = curcpl();
    228 	set_curcpl(ipl);
    229 	restore_interrupts(oldirqstate);
    230 	return (old);
    231 }
    232 
    233 int
    234 _spllower(int ipl)
    235 {
    236 	int	old = curcpl();
    237 
    238 	if (old <= ipl)
    239 		return (old);
    240 	splx(ipl);
    241 	return (old);
    242 }
    243 
    244 /*
    245  * ep93xx_intr_init:
    246  *
    247  *	Initialize the rest of the interrupt subsystem, making it
    248  *	ready to handle interrupts from devices.
    249  */
    250 void
    251 ep93xx_intr_init(void)
    252 {
    253 	struct intrq *iq;
    254 	int i;
    255 
    256 	vic1_intr_enabled = 0;
    257 	vic2_intr_enabled = 0;
    258 
    259 	for (i = 0; i < NIRQ; i++) {
    260 		iq = &intrq[i];
    261 		TAILQ_INIT(&iq->iq_list);
    262 
    263 		sprintf(iq->iq_name, "irq %d", i);
    264 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
    265 				     NULL, (i < VIC_NIRQ ? "vic1" : "vic2"),
    266 		                     iq->iq_name);
    267 	}
    268 	curcpu()->ci_intr_depth = 0;
    269 	set_curcpl(0);
    270 	hardware_spl_level = 0;
    271 
    272 	/* All interrupts should use IRQ not FIQ */
    273 	VIC1REG(EP93XX_VIC_IntSelect) = 0;
    274 	VIC2REG(EP93XX_VIC_IntSelect) = 0;
    275 
    276 	ep93xx_intr_calculate_masks();
    277 
    278 	/* Enable IRQs (don't yet use FIQs). */
    279 	enable_interrupts(I32_bit);
    280 }
    281 
    282 void *
    283 ep93xx_intr_establish(int irq, int ipl, int (*ih_func)(void *), void *arg)
    284 {
    285 	struct intrq*		iq;
    286 	struct intrhand*	ih;
    287 	u_int			oldirqstate;
    288 
    289 	if (irq < 0 || irq > NIRQ)
    290 		panic("ep93xx_intr_establish: IRQ %d out of range", irq);
    291 	if (ipl < 0 || ipl > NIPL)
    292 		panic("ep93xx_intr_establish: IPL %d out of range", ipl);
    293 
    294 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
    295 	if (ih == NULL)
    296 		return (NULL);
    297 
    298 	ih->ih_func = ih_func;
    299 	ih->ih_arg = arg;
    300 	ih->ih_irq = irq;
    301 	ih->ih_ipl = ipl;
    302 
    303 	iq = &intrq[irq];
    304 
    305 	oldirqstate = disable_interrupts(I32_bit);
    306 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
    307 	ep93xx_intr_calculate_masks();
    308 	restore_interrupts(oldirqstate);
    309 
    310 	return (ih);
    311 }
    312 
    313 void
    314 ep93xx_intr_disestablish(void *cookie)
    315 {
    316 	struct intrhand*	ih = cookie;
    317 	struct intrq*		iq = &intrq[ih->ih_irq];
    318 	u_int			oldirqstate;
    319 
    320 	oldirqstate = disable_interrupts(I32_bit);
    321 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
    322 	ep93xx_intr_calculate_masks();
    323 	restore_interrupts(oldirqstate);
    324 }
    325 
    326 void
    327 ep93xx_intr_dispatch(struct trapframe *frame)
    328 {
    329 	struct intrq*		iq;
    330 	struct intrhand*	ih;
    331 	u_int			oldirqstate;
    332 	int			pcpl;
    333 	uint32_t		vic1_hwpend;
    334 	uint32_t		vic2_hwpend;
    335 	int			irq;
    336 
    337 	pcpl = curcpl();
    338 
    339 	vic1_hwpend = VIC1REG(EP93XX_VIC_IRQStatus);
    340 	vic2_hwpend = VIC2REG(EP93XX_VIC_IRQStatus);
    341 
    342 	hardware_spl_level = pcpl;
    343 	ep93xx_set_intrmask(vic1_imask[pcpl] | vic1_hwpend,
    344 			     vic2_imask[pcpl] | vic2_hwpend);
    345 
    346 	vic1_hwpend &= ~vic1_imask[pcpl];
    347 	vic2_hwpend &= ~vic2_imask[pcpl];
    348 
    349 	if (vic1_hwpend) {
    350 		irq = ffs(vic1_hwpend) - 1;
    351 
    352 		iq = &intrq[irq];
    353 		iq->iq_ev.ev_count++;
    354 		curcpu()->ci_data.cpu_nintr++;
    355 		TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
    356 			set_curcpl(ih->ih_ipl);
    357 			oldirqstate = enable_interrupts(I32_bit);
    358 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    359 			restore_interrupts(oldirqstate);
    360 		}
    361 	} else if (vic2_hwpend) {
    362 		irq = ffs(vic2_hwpend) - 1;
    363 
    364 		iq = &intrq[irq + VIC_NIRQ];
    365 		iq->iq_ev.ev_count++;
    366 		curcpu()->ci_data.cpu_nintr++;
    367 		TAILQ_FOREACH(ih, &iq->iq_list, ih_list) {
    368 			set_curcpl(ih->ih_ipl);
    369 			oldirqstate = enable_interrupts(I32_bit);
    370 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    371 			restore_interrupts(oldirqstate);
    372 		}
    373 	}
    374 
    375 	set_curcpl(pcpl);
    376 	hardware_spl_level = pcpl;
    377 	ep93xx_set_intrmask(vic1_imask[pcpl], vic2_imask[pcpl]);
    378 
    379 #ifdef __HAVE_FAST_SOFTINTS
    380 	cpu_dosoftints();
    381 #endif
    382 }
    383