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      1 /*	$NetBSD: sa11x0_irq.S,v 1.21 2021/11/08 23:57:23 rin Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998 Mark Brinicombe.
      5  * Copyright (c) 1998 Causality Limited
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to the NetBSD Foundation
      9  * by IWAMOTO Toshihiro.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *      This product includes software developed by Mark Brinicombe
     22  *      for the NetBSD Project.
     23  * 4. The name of the company nor the name of the author may be used to
     24  *    endorse or promote products derived from this software without specific
     25  *    prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     28  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     29  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     30  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     31  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     32  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     33  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  */
     39 
     40 #include "opt_irqstats.h"
     41 
     42 #include "assym.h"
     43 
     44 #include <arm/asm.h>
     45 #include <arm/locore.h>
     46 #include <arm/sa11x0/sa11x0_reg.h>
     47 
     48 
     49 	.text
     50 	.align 0
     51 
     52 Lspl_masks:
     53 	.word	_C_LABEL(spl_masks)
     54 
     55 Lcpu_info_store:
     56         .word   _C_LABEL(cpu_info_store)
     57 
     58 	.globl	_C_LABEL(saipic_base)
     59 _C_LABEL(saipic_base):
     60 	.word	0x00000000
     61 
     62 #ifdef INTR_DEBUG
     63 Ldbg_str:
     64 	.asciz	"irq_entry %x %x\n"
     65 	.align 5
     66 #endif
     67 
     68 LOCK_CAS_CHECK_LOCALS
     69 
     70 AST_ALIGNMENT_FAULT_LOCALS
     71 
     72 /*
     73  * Register usage
     74  *
     75  *  r4  - Pointer to curcpu
     76  *  r5  - pointer to curlwp
     77  *  r6  - Address of current handler
     78  *  r7	- pspr mode
     79  *  r8  - Current IRQ requests.
     80  *  r9  - Used to count through possible IRQ bits.
     81  *  r10 - Pointer to handler pointer list
     82  */
     83 
     84 ASENTRY_NP(irq_entry)
     85 	sub	lr, lr, #0x00000004	/* Adjust the lr */
     86 
     87 	PUSHFRAMEINSVC			/* Push an interrupt frame */
     88 	ENABLE_ALIGNMENT_FAULTS		/* puts cur{cpu,lwp} in r4/r5 */
     89 
     90 	/* Load r8 with the SAIPIC interrupt requests */
     91 
     92 	ldr	r8, _C_LABEL(saipic_base)
     93 	ldr	r8, [r8, #(SAIPIC_IP)]	/* Load IRQ pending register */
     94 
     95 #ifdef INTR_DEBUG
     96 	adr	r0, Ldbg_str
     97 	mov	r1, r8
     98 	ldr	r2, _C_LABEL(saipic_base)
     99 	ldr	r2, [r2, #(SAIPIC_MR)]
    100 	bl	_C_LABEL(printf)
    101 #endif
    102 	/*
    103 	 * Note that we have entered the IRQ handler.
    104 	 * We are in SVC mode so we cannot use the processor mode
    105 	 * to determine if we are in an IRQ. Instead we will count the
    106 	 * each time the interrupt handler is nested.
    107 	 */
    108 
    109 	ldr	r1, [r4, #CI_INTR_DEPTH]
    110 	add	r1, r1, #1
    111 	str	r1, [r4, #CI_INTR_DEPTH]
    112 
    113 	/*
    114  	 * Need to block all interrupts at the IPL or lower for
    115 	 * all asserted interrupts.
    116 	 * This basically emulates hardware interrupt priority levels.
    117 	 * Means we need to go through the interrupt mask and for
    118 	 * every asserted interrupt we need to mask out all other
    119 	 * interrupts at the same or lower IPL.
    120 	 * If only we could wait until the main loop but we need to sort
    121 	 * this out first so interrupts can be re-enabled.
    122 	 *
    123 	 * This would benefit from a special ffs type routine
    124 	 */
    125 
    126 	mov	r9, #(NIPL - 1)
    127 	ldr	r10, Lspl_masks
    128 
    129 Lfind_highest_ipl:
    130 	ldr	r2, [r10, r9, lsl #2]
    131 	tst	r8, r2
    132 	subeq	r9, r9, #1
    133 	beq	Lfind_highest_ipl
    134 
    135 	/* r9 = SPL level of highest priority interrupt */
    136 	add	r9, r9, #1
    137 	ldr	r2, [r10, r9, lsl #2]
    138 
    139 	ldr	r1, [r4, #CI_CPL]
    140 	str	r9, [r4, #CI_CPL]
    141 	stmfd	sp!, {r1}
    142 
    143 	/* Update the SAIP irq masks */
    144 	bl	_C_LABEL(irq_setmasks)
    145 
    146 #ifdef INTR_DEBUG
    147 	stmfd	sp!, {r0,r1,r2}
    148 	adr	r0, Ldbg_str
    149 	mov	r1, #1
    150 	mov	r2, r9
    151 	bl	_C_LABEL(printf)
    152 	ldmia	sp!, {r0,r1,r2}
    153 #endif
    154         mrs     r0, cpsr		/* Enable IRQs */
    155 	bic	r0, r0, #I32_bit
    156 	msr	cpsr_all, r0
    157 
    158 	ldr	r10, Lirqhandlers
    159         mov	r9, #0x00000001
    160 
    161 irqloop:
    162 	/* This would benefit from a special ffs type routine */
    163 	tst	r8, r9			/* Is a bit set ? */
    164 	beq	nextirq			/* No ? try next bit */
    165 
    166 	ldr	r6, [r10]		/* Get address of first handler structure */
    167 
    168 	teq	r6, #0x00000000		/* Do we have a handler */
    169 	moveq	r0, r8			/* IRQ requests as arg 0 */
    170 	beq	_C_LABEL(stray_irqhandler) /* call special handler */
    171 
    172 	ldr	r0, [r4, #(CI_CC_NINTR)]
    173 	ldr	r1, [r4, #(CI_CC_NINTR+4)]
    174 #ifdef _ARMEL
    175 	adds	r0, r0, #0x00000001
    176 	adc	r1, r1, #0x00000001
    177 #else
    178 	adds	r1, r1, #0x00000001
    179 	adc	r0, r0, #0x00000000
    180 #endif
    181 	str	r0, [r4, #(CI_CC_NINTR)]
    182 	str	r1, [r4, #(CI_CC_NINTR+4)]
    183 
    184 	/*
    185 	 * XXX: Should stats be accumulated for every interrupt routine
    186 	 * called or for every physical interrupt that is serviced.
    187 	 */
    188 
    189 #ifdef IRQSTATS
    190 	ldr	r0, Lintrcnt
    191 	ldr	r1, [r6, #(IH_COUNT)]
    192 
    193 	add	r0, r0, r1, lsl #2
    194 	ldr	r1, [r0]
    195 	add	r1, r1, #0x00000001
    196 	str	r1, [r0]
    197 #endif	/* IRQSTATS */
    198 
    199 irqchainloop:
    200 #ifdef INTR_DEBUG
    201 	stmfd	sp!, {r0,r1,r2}
    202 	adr	r0, Ldbg_str
    203 	mov	r1, #2
    204 	bl	_C_LABEL(printf)
    205 	ldmia	sp!, {r0,r1,r2}
    206 #endif
    207 	ldr	r0, [r6, #(IH_ARG)]	/* Get argument pointer */
    208 	teq	r0, #0x00000000		/* If arg is zero pass stack frame */
    209 	addeq	r0, sp, #4		/* ... stack frame [XXX needs care] */
    210 	mov	lr, pc			/* return address */
    211 	ldr	pc, [r6, #(IH_FUNC)]	/* Call handler */
    212 
    213 	teq	r0, #0x00000001		/* Was the irq serviced ? */
    214 	beq	irqdone
    215 
    216 	ldr	r6, [r6, #(IH_NEXT)]
    217 	teq	r6, #0x00000000
    218 	bne	irqchainloop
    219 
    220 irqdone:
    221 nextirq:
    222 	add	r10, r10, #0x00000004	/* update pointer to handlers */
    223 	mov	r9, r9, lsl #1		/* move on to next bit */
    224 	teq	r9, #(1 << 31)		/* done the last bit ? */
    225 	bne	irqloop			/* no - loop back. */
    226 
    227 	ldmfd	sp!, {r2}
    228 	str	r2, [r4, #CI_CPL]
    229 
    230 	/* Restore previous disabled mask */
    231 	bl	_C_LABEL(irq_setmasks)
    232 
    233 	/* Kill IRQ's in preparation for exit */
    234         mrs     r0, cpsr
    235         orr     r0, r0, #(I32_bit)
    236         msr     cpsr_all, r0
    237 
    238 #ifdef INTR_DEBUG
    239 	adr	r0, Ldbg_str
    240 	mov	r1, #3
    241 	ldr	r2, _C_LABEL(saipic_base)
    242 	ldr	r2, [r2, #(SAIPIC_MR)]
    243 	bl	_C_LABEL(printf)
    244 #endif
    245 
    246 	/* Decrement the nest count */
    247 	ldr	r1, [r4, #CI_INTR_DEPTH]
    248 	sub	r1, r1, #1
    249 	str	r1, [r4, #CI_INTR_DEPTH]
    250 
    251 	LOCK_CAS_CHECK
    252 
    253 	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
    254 	PULLFRAMEFROMSVCANDEXIT
    255 
    256 	/* NOT REACHED */
    257 	b	. - 8
    258 
    259 ENTRY(irq_setmasks)
    260 	stmfd	sp!, {r0, r1, r4, lr}	/* Preserve registers */
    261 
    262 	/* Disable interrupts */
    263 	mrs	r1, cpsr
    264 	orr	r3, r1,  #(I32_bit)
    265 	msr	cpsr_all, r3
    266 
    267 	/* Calculate interrupt mask */
    268 	ldr	r0, Lspl_masks
    269 	ldr	r4, Lcpu_info_store
    270 	ldr	r2, [r4, #CI_CPL]
    271 	ldr	r2, [r0, r2, lsl #2]
    272 
    273 	ldr	r0, _C_LABEL(saipic_base)
    274 	str	r2, [r0, #(SAIPIC_MR)]	/* Set mask register */
    275 
    276 	/* Restore old cpsr and exit */
    277 	msr	cpsr_all, r1
    278 	ldmia	sp!, {r0, r1, r4, pc}	/* Restore registers */
    279 
    280 #ifdef IRQSTATS
    281 Lintrcnt:
    282 	.word	_C_LABEL(intrcnt)
    283 #endif
    284 
    285 Lirqhandlers:
    286 	.word	_C_LABEL(irqhandlers)	/* Pointer to array of irqhandlers */
    287 
    288 
    289 #ifdef IRQSTATS
    290 	.global _C_LABEL(intrnames), _C_LABEL(eintrnames)
    291 	.global _C_LABEL(eintrcnt)
    292 _C_LABEL(intrnames):
    293 _C_LABEL(eintrnames):
    294 _C_LABEL(eintrcnt):
    295 
    296 	.globl	_C_LABEL(intrcnt), _C_LABEL(sintrcnt)
    297 
    298 _C_LABEL(intrcnt):
    299 	.space	ICU_LEN*4  /* XXX Should be linked to number of interrupts */
    300 
    301 _C_LABEL(sintrcnt):
    302 	.space 32*4
    303 #endif
    304