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sa11x0_irq.S revision 1.3
      1 /*	$NetBSD: sa11x0_irq.S,v 1.3 2002/07/19 18:36:26 ichiro 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 #include <machine/asm.h>
     44 #include <machine/cpu.h>
     45 #include <machine/frame.h>
     46 #include <arm/sa11x0/sa11x0_reg.h>
     47 
     48 
     49 	.text
     50 	.align 0
     51 
     52 Lcurrent_spl_level:
     53 	.word	_C_LABEL(current_spl_level)
     54 
     55 Lcurrent_intr_depth:
     56 	.word	_C_LABEL(current_intr_depth)
     57 
     58 Lspl_masks:
     59 	.word	_C_LABEL(spl_masks)
     60 
     61 	.globl	_C_LABEL(saipic_base)
     62 _C_LABEL(saipic_base):
     63 	.word	0x00000000
     64 
     65 #ifdef INTR_DEBUG
     66 Ldbg_str:
     67 	.asciz	"irq_entry %x %x\n"
     68 #endif
     69 
     70 /*
     71  * Regsister usage
     72  *
     73  *  r6  - Address of current handler
     74  *  r7  - Pointer to handler pointer list
     75  *  r8  - Current IRQ requests.
     76  *  r9  - Used to count through possible IRQ bits.
     77  *  r10 - Base address of SAIP
     78  */
     79 
     80 ASENTRY_NP(irq_entry)
     81 	sub	lr, lr, #0x00000004	/* Adjust the lr */
     82 
     83 	PUSHFRAMEINSVC			/* Push an interrupt frame */
     84 
     85 	/* Load r8 with the SAIPIC interrupt requests */
     86 
     87 	ldr	r10, [pc, #_C_LABEL(saipic_base) - . - 8]
     88 	ldr	r8, [r10, #(SAIPIC_IP)]	/* Load IRQ pending register */
     89 
     90 #ifdef INTR_DEBUG
     91 	ldr	r2, [r10, #(SAIPIC_MR)]
     92 	add	r0, pc, #Ldbg_str - . - 8
     93 	mov	r1, r8
     94 	bl	_C_LABEL(printf)
     95 #endif
     96 	/*
     97 	 * Note that we have entered the IRQ handler.
     98 	 * We are in SVC mode so we cannot use the processor mode
     99 	 * to determine if we are in an IRQ. Instead we will count the
    100 	 * each time the interrupt handler is nested.
    101 	 */
    102 
    103 	ldr	r0, Lcurrent_intr_depth
    104 	ldr	r1, [r0]
    105 	add	r1, r1, #1
    106 	str	r1, [r0]
    107 
    108 	/*
    109  	 * Need to block all interrupts at the IPL or lower for
    110 	 * all asserted interrupts.
    111 	 * This basically emulates hardware interrupt priority levels.
    112 	 * Means we need to go through the interrupt mask and for
    113 	 * every asserted interrupt we need to mask out all other
    114 	 * interrupts at the same or lower IPL.
    115 	 * If only we could wait until the main loop but we need to sort
    116 	 * this out first so interrupts can be re-enabled.
    117 	 *
    118 	 * This would benefit from a special ffs type routine
    119 	 */
    120 
    121 	mov	r9, #(_SPL_LEVELS - 1)
    122 	ldr	r7, Lspl_masks
    123 
    124 Lfind_highest_ipl:
    125 	ldr	r2, [r7, r9, lsl #2]
    126 	tst	r8, r2
    127 	subeq	r9, r9, #1
    128 	beq	Lfind_highest_ipl
    129 
    130 	/* r9 = SPL level of highest priority interrupt */
    131 	add	r9, r9, #1
    132 	ldr	r2, [r7, r9, lsl #2]
    133 	mvn	r2, r2
    134 
    135 	ldr	r0, Lcurrent_spl_level
    136 	ldr	r1, [r0]
    137 	str	r9, [r0]
    138 	stmfd	sp!, {r1}
    139 
    140 	/* Update the SAIP irq masks */
    141 	bl	_C_LABEL(irq_setmasks)
    142 
    143 #ifdef INTR_DEBUG
    144 	stmfd	sp!, {r0,r1,r2}
    145 	add	r0, pc, #Ldbg_str - . - 8
    146 	mov	r1, #1
    147 	mov	r2, r9
    148 	bl	_C_LABEL(printf)
    149 	ldmia	sp!, {r0,r1,r2}
    150 #endif
    151         mrs     r0, cpsr_all		/* Enable IRQ's */
    152 	bic	r0, r0, #I32_bit
    153 	msr	cpsr_all, r0
    154 
    155 	ldr	r7, [pc, #Lirqhandlers - . - 8]
    156         mov	r9, #0x00000001
    157 
    158 irqloop:
    159 	/* This would benefit from a special ffs type routine */
    160 	tst	r8, r9			/* Is a bit set ? */
    161 	beq	nextirq			/* No ? try next bit */
    162 
    163 	ldr	r6, [r7]		/* Get address of first handler structure */
    164 
    165 	teq	r6, #0x00000000		/* Do we have a handler */
    166 	moveq	r0, r8			/* IRQ requests as arg 0 */
    167 	beq	_C_LABEL(stray_irqhandler) /* call special handler */
    168 
    169         ldr	r0, Lcnt		/* Stat info */
    170 	ldr	r1, [r0, #(V_INTR)]
    171 	add	r1, r1, #0x00000001
    172 	str	r1, [r0, #(V_INTR)]
    173 
    174 	/*
    175 	 * XXX: Should stats be accumlated for every interrupt routine
    176 	 * called or for every physical interrupt that is serviced.
    177 	 */
    178 
    179 #ifdef IRQSTATS
    180 	ldr	r0, Lintrcnt
    181 	ldr	r1, [r6, #(IH_COUNT)]
    182 
    183 	add	r0, r0, r1, lsl #2
    184 	ldr	r1, [r0]
    185 	add	r1, r1, #0x00000001
    186 	str	r1, [r0]
    187 #endif	/* IRQSTATS */
    188 
    189 irqchainloop:
    190 #ifdef INTR_DEBUG
    191 	stmfd	sp!, {r0,r1,r2}
    192 	add	r0, pc, #Ldbg_str - . - 8
    193 	mov	r1, #2
    194 	bl	_C_LABEL(printf)
    195 	ldmia	sp!, {r0,r1,r2}
    196 #endif
    197 	add	lr, pc, #nextinchain - . - 8	/* return address */
    198 	ldr	r0, [r6, #(IH_ARG)]	/* Get argument pointer */
    199 	teq	r0, #0x00000000		/* If arg is zero pass stack frame */
    200 	addeq	r0, sp, #4		/* ... stack frame [XXX needs care] */
    201 	ldr	pc, [r6, #(IH_FUNC)]	/* Call handler */
    202 
    203 nextinchain:
    204 	teq	r0, #0x00000001		/* Was the irq serviced ? */
    205 	beq	irqdone
    206 
    207 	ldr	r6, [r6, #(IH_NEXT)]
    208 	teq	r6, #0x00000000
    209 	bne	irqchainloop
    210 
    211 irqdone:
    212 nextirq:
    213 	add	r7, r7, #0x00000004	/* update pointer to handlers */
    214 	mov	r9, r9, lsl #1		/* move on to next bit */
    215 	teq	r9, #(1 << 31)		/* done the last bit ? */
    216 	bne	irqloop			/* no - loop back. */
    217 
    218 	ldmfd	sp!, {r2}
    219 	ldr	r1, Lcurrent_spl_level
    220 	str	r2, [r1]
    221 
    222 	/* Restore previous disabled mask */
    223 	bl	_C_LABEL(irq_setmasks)
    224 
    225 	bl	_C_LABEL(dosoftints)	/* Handle the soft interrupts */
    226 
    227 	/* Manage AST's. Maybe this should be done as a soft interrupt ? */
    228 	ldr	r0, [sp]		/* Get the SPSR from stack */
    229 
    230 	and	r0, r0, #(PSR_MODE)	/* Test for USR32 mode before the IRQ */
    231 	teq	r0, #(PSR_USR32_MODE)
    232 	ldreq	r0, Lastpending		/* Do we have an AST pending ? */
    233 	ldreq	r1, [r0]
    234 	teqeq	r1, #0x00000001
    235 
    236 	beq	irqast			/* call the AST handler */
    237 
    238 	/* Kill IRQ's in preparation for exit */
    239         mrs     r0, cpsr_all
    240         orr     r0, r0, #(I32_bit)
    241         msr     cpsr_all, r0
    242 
    243 #ifdef INTR_DEBUG
    244 	add	r0, pc, #Ldbg_str - . - 8
    245 	mov	r1, #3
    246 	ldr	r2, [r10, #(SAIPIC_MR)]
    247 	bl	_C_LABEL(printf)
    248 #endif
    249 
    250 	/* Decrement the nest count */
    251 	ldr	r0, Lcurrent_intr_depth
    252 	ldr	r1, [r0]
    253 	sub	r1, r1, #1
    254 	str	r1, [r0]
    255 
    256 	PULLFRAMEFROMSVCANDEXIT
    257 
    258 	/* NOT REACHED */
    259 	b	. - 8
    260 
    261 	/*
    262 	 * Ok, snag with current intr depth ...
    263 	 * If ast() calls mi_sleep() the current_intr_depth will not be
    264 	 * decremented until the process is woken up. This can result
    265 	 * in the system believing it is still in the interrupt handler.
    266 	 * If we are calling ast() then correct the current_intr_depth
    267 	 * before the call.
    268 	 */
    269 irqast:
    270 	mov	r1, #0x00000000		/* Clear ast_pending */
    271 	str	r1, [r0]
    272 
    273 	/* Kill IRQ's so we atomically decrement current_intr_depth */
    274         mrs     r2, cpsr_all
    275         orr     r3, r2, #(I32_bit)
    276         msr     cpsr_all, r3
    277 
    278 	/* Decrement the interrupt nesting count */
    279 	ldr	r0, Lcurrent_intr_depth
    280 	ldr	r1, [r0]
    281 	sub	r1, r1, #1
    282 	str	r1, [r0]
    283 
    284 	/* Restore IRQ's */
    285         msr     cpsr_all, r2
    286 
    287 	mov	r0, sp
    288 	bl	_C_LABEL(ast)
    289 
    290 	/* Kill IRQ's in preparation for exit */
    291         mrs     r0, cpsr_all
    292         orr     r0, r0, #(I32_bit)
    293         msr     cpsr_all, r0
    294 
    295 	PULLFRAMEFROMSVCANDEXIT
    296 
    297 	/* NOT REACHED */
    298 	b	. - 8
    299 
    300 
    301 ENTRY(irq_setmasks)
    302 	/* Disable interrupts */
    303 	mrs	r3, cpsr_all
    304 	orr	r1, r3,  #(I32_bit)
    305 	msr	cpsr_all, r1
    306 
    307 	/* Calculate interrupt mask */
    308 	ldr	r0, Lspl_masks
    309 	ldr	r2, Lcurrent_spl_level
    310 	ldr	r2, [r2]
    311 	ldr	r2, [r0, r2, lsl #2]
    312 
    313 	ldr	r0, [pc, #_C_LABEL(saipic_base) - . - 8]
    314 	str	r2, [r0, #(SAIPIC_MR)]	/* Set mask register */
    315 
    316 	/* Restore old cpsr and exit */
    317 	msr	cpsr_all, r3
    318 	mov	pc, lr
    319 
    320 Lcnt:
    321 	.word	_C_LABEL(uvmexp)
    322 
    323 #ifdef IRQSTATS
    324 Lintrcnt:
    325 	.word	_C_LABEL(intrcnt)
    326 #endif
    327 
    328 Lirqhandlers:
    329 	.word	_C_LABEL(irqhandlers)	/* Pointer to array of irqhandlers */
    330 
    331 Lastpending:
    332 	.word	_C_LABEL(astpending)
    333 
    334 
    335 
    336 #ifdef IRQSTATS
    337 	.globl	_C_LABEL(intrcnt), _C_LABEL(sintrcnt)
    338 
    339 _C_LABEL(intrcnt):
    340 	.space	ICU_LEN*4  /* XXX Should be linked to number of interrupts */
    341 
    342 _C_LABEL(sintrcnt):
    343 	.space 32*4
    344 #endif
    345