NetBSD-5.0.2/sys/arch/shark/isa/isa_irq.S
/* $NetBSD: isa_irq.S,v 1.12 2008/04/27 18:58:47 matt Exp $ */
/*
* Copyright 1997
* Digital Equipment Corporation. All rights reserved.
*
* This software is furnished under license and may be used and
* copied only in accordance with the following terms and conditions.
* Subject to these conditions, you may download, copy, install,
* use, modify and distribute this software in source and/or binary
* form. No title or ownership is transferred hereby.
*
* 1) Any source code used, modified or distributed must reproduce
* and retain this copyright notice and list of conditions as
* they appear in the source file.
*
* 2) No right is granted to use any trade name, trademark, or logo of
* Digital Equipment Corporation. Neither the "Digital Equipment
* Corporation" name nor any trademark or logo of Digital Equipment
* Corporation may be used to endorse or promote products derived
* from this software without the prior written permission of
* Digital Equipment Corporation.
*
* 3) This software is provided "AS-IS" and any express or implied
* warranties, including but not limited to, any implied warranties
* of merchantability, fitness for a particular purpose, or
* non-infringement are disclaimed. In no event shall DIGITAL be
* liable for any damages whatsoever, and in particular, DIGITAL
* shall not be liable for special, indirect, consequential, or
* incidental damages or damages for lost profits, loss of
* revenue or loss of use, whether such damages arise in contract,
* negligence, tort, under statute, in equity, at law or otherwise,
* even if advised of the possibility of such damage.
*/
/*
* Copyright (c) 1994-1998 Mark Brinicombe.
* Copyright (c) 1994 Brini.
* All rights reserved.
*
* This code is derived from software written for Brini by Mark Brinicombe
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Mark Brinicombe
* for the NetBSD Project.
* 4. The name of the company nor the name of the author may be used to
* endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* from: irq.S
*
* Low level irq and fiq handlers
*
* Created : 27/09/94
*/
#include "assym.h"
#include <machine/asm.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <dev/isa/isareg.h>
#include <shark/isa/icu.h>
#include <machine/irqhandler.h>
.text
.align 0
/*
*
* irq_entry
*
* Main entry point for the IRQ vector
*
* This function reads the irq request bits in the IOMD registers
* IRQRQA, IRQRQB and DMARQ
* It then calls an installed handler for each bit that is set.
* The function stray_irqhandler is called if a handler is not defined
* for a particular interrupt.
* If a interrupt handler is found then it is called with r0 containing
* the argument defined in the handler structure. If the field ih_arg
* is zero then a pointer to the IRQ frame on the stack is passed instead.
*/
.Ldisabled_mask:
.word _C_LABEL(disabled_mask)
.Lvam_io_data:
.word _C_LABEL(isa_io_bs_tag)
.Lspl_masks:
.word _C_LABEL(spl_masks)
/*
* Register usage
*
* r6 - Address of current handler
* r7 - Pointer to handler pointer list
* r8 - Current IRQ requests.
* r9 - Used to count through possible IRQ bits.
* r10 - Base address of IOMD
*/
/* Some documentation is in isa_machdep.c */
ASENTRY_NP(irq_entry)
sub lr, lr, #0x00000004 /* Adjust the lr */
PUSHFRAMEINSVC /* Push an interrupt frame */
ENABLE_ALIGNMENT_FAULTS /* cpuinfo is in r4 after execution */
/* Load r8 with the ISA 8259 irqs */
/* r8 <- irq's pending [15:0] */
/* address of 8259 #1 */
ldr r0, .Lvam_io_data
ldr r0, [r0]
ldrb r8, [r0, #IO_ICU1] /* ocw3 = irr */
/* clear the IRR bits that are currently masked. */
ldr r2, .Li8259_mask
ldr r2, [r2]
mvn r2, r2 /* disabled -> enabled */
/* address of 8259 #2 */
tst r2, #(1 << IRQ_SLAVE) /* if slave is enabled */
tstne r8, #(1 << IRQ_SLAVE) /* anything from slave? */
ldrneb r1, [r0, #IO_ICU2] /* ocw3 = irr */
orrne r8, r8, r1, lsl #8
and r8, r8, r2 /* clear disabled */
/* clear IRQ 2, which is only used for slave 8259 */
bic r8, r8, #(1 << IRQ_SLAVE)
/*
* Note that we have entered the IRQ handler.
* We are in SVC mode so we cannot use the processor mode
* to determine if we are in an IRQ. Instead we will count the
* each time the interrupt handler is nested.
*/
ldr r1, [r4, #CI_INTR_DEPTH]
add r1, r1, #1
str r1, [r4, #CI_INTR_DEPTH]
/* Block the current requested interrupts */
ldr r1, .Ldisabled_mask
ldr r0, [r1]
stmfd sp!, {r0}
orr r0, r0, r8
/*
* Need to block all interrupts at the IPL or lower for
* all asserted interrupts.
* This basically emulates hardware interrupt priority levels.
* Means we need to go through the interrupt mask and for
* every asserted interrupt we need to mask out all other
* interrupts at the same or lower IPL.
* If only we could wait until the main loop but we need to sort
* this out first so interrupts can be re-enabled.
*
* This would benefit from a special ffs type routine
*/
mov r9, #(NIPL - 1)
ldr r7, .Lspl_masks
.Lfind_highest_ipl:
ldr r2, [r7, r9, lsl #2]
tst r8, r2
subeq r9, r9, #1
beq .Lfind_highest_ipl
/* r9 = SPL level of highest priority interrupt */
add r9, r9, #1
ldr r2, [r7, r9, lsl #2]
mvn r2, r2
orr r0, r0, r2
str r0, [r1]
ldr r1, [r4, #CI_CPL]
str r9, [r4, #CI_CPL]
stmfd sp!, {r1}
/* Update the IOMD irq masks */
bl _C_LABEL(irq_setmasks)
mrs r0, cpsr_all /* Enable IRQ's */
bic r0, r0, #I32_bit
msr cpsr_all, r0
ldr r7, .Lirqhandlers
mov r9, #0x00000001
irqloop:
/* This would benefit from a special ffs type routine */
tst r8, r9 /* Is a bit set ? */
beq nextirq /* No ? try next bit */
ldr r6, [r7] /* Get address of first handler structure */
teq r6, #0x00000000 /* Do we have a handler */
moveq r0, r8 /* IRQ requests as arg 0 */
beq _C_LABEL(stray_irqhandler) /* call special handler */
ldr r0, .Lcnt
ldr r1, [r0, #(V_INTR)]
add r1, r1, #0x00000001
str r1, [r0, #(V_INTR)]
irqchainloop:
ldr r0, [r6, #(IH_ARG)] /* Get argument pointer */
teq r0, #0x00000000 /* If arg is zero pass stack frame */
addeq r0, sp, #8 /* ... stack frame */
mov lr, pc /* return address */
ldr pc, [r6, #(IH_FUNC)] /* Call handler */
teq r0, #0x00000001 /* Was the irq serviced ? */
beq irqdone
ldr r6, [r6, #(IH_NEXT)]
teq r6, #0x00000000
bne irqchainloop
b nextirq
irqdone:
add r3, r6, #IH_EV_COUNT /* get address of ih's ev_count */
ldmia r3, {r1-r2} /* load ev_count */
adds r1, r1, #0x00000001 /* 64bit incr (lo) */
adc r2, r2, #0x00000000 /* 64bit incr (hi) */
stmia r3, {r1-r2} /* store ev_count */
nextirq:
add r7, r7, #0x00000004 /* update pointer to handlers */
mov r9, r9, lsl #1 /* move on to next bit */
teq r9, #(1 << 16) /* done the last bit ? */
bne irqloop /* no - loop back. */
ldmfd sp!, {r2}
str r2, [r4, #CI_CPL]
/* Restore previous disabled mask */
ldmfd sp!, {r2}
ldr r1, .Ldisabled_mask
str r2, [r1]
bl _C_LABEL(irq_setmasks)
#ifdef __HAVE_FAST_SOFTINTS
bl _C_LABEL(dosoftints) /* Handle the soft interrupts */
#endif
/* Kill IRQ's in preparation for exit */
mrs r0, cpsr_all
orr r0, r0, #(I32_bit)
msr cpsr_all, r0
/* Decrement the nest count */
ldr r1, [r4, #CI_INTR_DEPTH]
sub r1, r1, #1
str r1, [r4, #CI_INTR_DEPTH]
LOCK_CAS_CHECK
DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
PULLFRAMEFROMSVCANDEXIT
/* NOT REACHED */
b . - 8
.Lcurrent_mask:
.word _C_LABEL(current_mask) /* irq's that are usable */
.Lcpu_info_store:
.word _C_LABEL(cpu_info_store)
LOCK_CAS_CHECK_LOCALS
AST_ALIGNMENT_FAULT_LOCALS
ENTRY(irq_setmasks)
/* Disable interrupts */
mrs r3, cpsr_all
orr r1, r3, #(I32_bit)
msr cpsr_all, r1
/* Calculate interrupt mask */
ldr r1, .Lcurrent_mask /* All the enabled interrupts */
ldrh r1, [r1] /* get hardware bits of mask */
/* .word 0xe0d110b0 */ /* hand-assembled ldrh r1, [r1] */
ldr r0, .Lspl_masks
ldr r2, .Lcpu_info_store
ldr r2, [r2, #CI_CPL]
ldr r2, [r0, r2, lsl #2]
and r1, r1, r2
ldr r2, .Ldisabled_mask /* Block due to active interrupts */
ldr r2, [r2]
bic r1, r1, r2
/* since 8259's are so slow to access, this code does everything
possible to avoid them */
/* get current mask: these are the bits */
ldr r0, .Li8259_mask
ldr r2, [r0]
/* r2 = 0000.0000.0000.0000.ZZZZ.ZZZZ.ZZZZ.ZZZZ */
/* see if there's anything enabled on 8259 #2 */
tst r1, #0xff00
biceq r1, r1, #(1 << IRQ_SLAVE) /* no, so disable it */
orrne r1, r1, #(1 << IRQ_SLAVE) /* yes, so enable it */
/* eq => r1 = 0000.0000.0000.0000.0000.0000.MMMM.M0MM
ne => r1 = 0000.0000.0000.0000.MMMM.MMMM.MMMM.M1MM */
/* 8259 bit high => disable */
mvn r1, r1
/* eq => r1 = 1111.1111.1111.1111.1111.1111.YYYY.Y1YY
ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY
(for each bit position Y = !M) */
orreq r1, r2, r1, lsl #16
/* eq => r1 = 1111.1111.YYYY.Y1YY.ZZZZ.ZZZZ.ZZZZ.ZZZZ
ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY */
orreq r1, r1, #0x000000FF
/* eq => r1 = 1111.1111.YYYY.Y1YY.ZZZZ.ZZZZ.1111.1111
ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY */
and r1, r1, r1, lsr #16
/* eq => r1 = 0000.0000.0000.0000.ZZZZ.ZZZZ.YYYY.Y1YY
ne => r1 = 0000.0000.0000.0000.YYYY.YYYY.YYYY.Y0YY */
/* if old = new, don't bother to set again.
fast path to exit, since 8259's are so slow anyway */
eors r2, r1, r2 /* which bits are different? */
msreq cpsr_all, r3 /* no bits are different, return */
moveq pc, lr
/* have to set at least one of the 8259's, store new mask */
str r1, [r0]
ldr r0, .Lvam_io_data
ldr r0, [r0]
/* see if there's any change for 8259 #1 (master) */
tst r2, #0x00FF /* bottom 8 bits different? */
strneb r1, [r0, #(IO_ICU1 + 1)] /* icu1 / ocw1 */
/* anything for 8259 #2? */
tst r2, #0xFF00
mov r1, r1, lsr #8 /* next byte */
strneb r1, [r0, #(IO_ICU2 + 1)] /* icu2 / ocw1 */
/* Restore old cpsr and exit */
msr cpsr_all, r3
mov pc, lr
.Lcnt:
.word _C_LABEL(uvmexp)
.Li8259_mask:
.word _C_LABEL(i8259_mask)
.Lirqhandlers:
.word _C_LABEL(irqhandlers) /* Pointer to array of irqhandlers */