NetBSD-5.0.2/sys/arch/arm/iomd/iomd_irq.S
/* $NetBSD: iomd_irq.S,v 1.12 2008/08/19 19:10:08 matt Exp $ */
/*
* 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.
*
* Low level irq and fiq handlers
*
* Created : 27/09/94
*/
#include "opt_irqstats.h"
#include "assym.h"
#include <machine/asm.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <arm/iomd/iomdreg.h>
.text
.align 0
/*
* ffs table used for servicing irq's quickly must be here otherwise adr can't
* reach it
* The algorithm for ffs was devised by D. Seal and posted to
* comp.sys.arm on 16 Feb 1994.
*/
.type Lirq_ffs_table, _ASM_TYPE_OBJECT;
Lirq_ffs_table:
/* same as ffs table but all nums are -1 from that */
/* 0 1 2 3 4 5 6 7 */
.byte 0, 0, 1, 12, 2, 6, 0, 13 /* 0- 7 */
.byte 3, 0, 7, 0, 0, 0, 0, 14 /* 8-15 */
.byte 10, 4, 0, 0, 8, 0, 0, 25 /* 16-23 */
.byte 0, 0, 0, 0, 0, 21, 27, 15 /* 24-31 */
.byte 31, 11, 5, 0, 0, 0, 0, 0 /* 32-39 */
.byte 9, 0, 0, 24, 0, 0, 20, 26 /* 40-47 */
.byte 30, 0, 0, 0, 0, 23, 0, 19 /* 48-55 */
.byte 29, 0, 22, 18, 28, 17, 16, 0 /* 56-63 */
/*
*
* 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.
*/
Lcurrent_spl_level:
.word _C_LABEL(cpu_info_store) + CI_CPL
Ldisabled_mask:
.word _C_LABEL(disabled_mask)
Lspl_masks:
.word _C_LABEL(spl_masks)
LOCK_CAS_CHECK_LOCALS
AST_ALIGNMENT_FAULT_LOCALS
/*
* Register usage
*
* r4 - Address of cpu_info
* r5 - Address of ffs table
* r6 - Address of current handler
* r7 - Pointer to handler pointer list
* r8 - Current IRQ requests.
* r10 - Base address of IOMD
* r11 - IRQ requests still to service.
*/
Liomd_base:
.word _C_LABEL(iomd_base)
Larm7500_ioc_found:
.word _C_LABEL(arm7500_ioc_found)
ASENTRY_NP(irq_entry)
sub lr, lr, #0x00000004 /* Adjust the lr */
PUSHFRAMEINSVC /* Push an interrupt frame */
ENABLE_ALIGNMENT_FAULTS
/* Load r8 with the IOMD interrupt requests */
ldr r10, Liomd_base
ldr r10, [r10] /* Point to the IOMD */
ldrb r8, [r10, #(IOMD_IRQRQA << 2)] /* Get IRQ request A */
ldrb r9, [r10, #(IOMD_IRQRQB << 2)] /* Get IRQ request B */
orr r8, r8, r9, lsl #8
ldr r9, Larm7500_ioc_found
ldr r9, [r9] /* get the flag */
cmp r9, #0
beq skip_extended_IRQs_reading
/* ARM 7500 only */
ldrb r9, [r10, #(IOMD_IRQRQC << 2)] /* Get IRQ request C */
orr r8, r8, r9, lsl #16
ldrb r9, [r10, #(IOMD_IRQRQD << 2)] /* Get IRQ request D */
orr r8, r8, r9, lsl #24
ldrb r9, [r10, #(IOMD_DMARQ << 2)] /* Get DMA Request */
tst r9, #0x10
orrne r8, r8, r9, lsl #27
b irq_entry_continue
skip_extended_IRQs_reading:
/* non ARM7500 machines */
ldrb r9, [r10, #(IOMD_DMARQ << 2)] /* Get DMA Request */
orr r8, r8, r9, lsl #16
irq_entry_continue:
and r0, r8, #0x7d /* Clear IOMD IRQA bits */
strb r0, [r10, #(IOMD_IRQRQA << 2)]
/*
* 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 r0, [r4, #CI_INTR_DEPTH]
add r0, r0, #1
str r0, [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 r0, [r4, #CI_CPL]
str r9, [r4, #CI_CPL]
stmfd sp!, {r0}
/* 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
/*
* take a copy of the IRQ request so that we can strip bits out of it
* note that we only use 24 bits with iomd2 chips
*/
ldr r5, Larm7500_ioc_found
ldr r5, [r5] /* get the flag */
cmp r5, #0
movne r11, r8 /* ARM7500 -> copy all bits */
biceq r11, r8, #0xff000000 /* !ARM7500 -> only use 24 bit */
/* ffs routine to find first irq to service */
/* standard trick to isolate bottom bit in a0 or 0 if a0 = 0 on entry */
rsb r5, r11, #0
ands r10, r11, r5
/*
* now r10 has at most 1 set bit, call this X
* if X = 0, branch to exit code
*/
beq exitirq
irqloop:
adr r5, Lirq_ffs_table
/*
* at this point:
* r5 = address of ffs table
* r7 = address of irq handlers table
* r8 = irq request
* r10 = bit of irq to be serviced
* r11 = bitmask of IRQ's to service
*/
/* find the set bit */
orr r9, r10, r10, lsl #4 /* X * 0x11 */
orr r9, r9, r9, lsl #6 /* X * 0x451 */
rsb r9, r9, r9, lsl #16 /* X * 0x0450fbaf */
/* fetch the bit number */
ldrb r9, [r5, r9, lsr #26 ]
/*
* r9 = irq to service
*/
/* apologies for the dogs dinner of code here, but it's in an attempt
* to minimise stalling on SA's, hence lots of things happen here:
* - getting address of handler, if it doesn't exist we call
* stray_irqhandler this is assumed to be rare so we don't
* care about performance for it
* - statinfo is updated
* - unsetting of the irq bit in r11
* - irq stats (if enabled) also get put in the mix
*/
ldr r5, Lcnt /* Stat info A */
ldr r6, [r7, r9, lsl #2] /* Get address of first handler structure */
ldr r1, [r5, #(V_INTR)] /* Stat info B */
teq r6, #0x00000000 /* Do we have a handler */
moveq r0, r8 /* IRQ requests as arg 0 */
adreq lr, nextirq /* return Address */
beq _C_LABEL(stray_irqhandler) /* call special handler */
#ifdef IRQSTATS
ldr r2, Lintrcnt
ldr r3, [r6, #(IH_NUM)]
#endif
/* stat info C */
add r1, r1, #0x00000001
str r1, [r5, #(V_INTR)]
#ifdef IRQSTATS
ldr r3, [r2, r3, lsl #2]!
#endif
bic r11, r11, r10 /* clear the IRQ bit */
#ifdef IRQSTATS
add r3, r3, #0x00000001
str r3, [r2]
#endif /* IRQSTATS */
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 [XXX needs care] */
mov lr, pc /* return address */
ldr pc, [r6, #(IH_FUNC)] /* Call handler */
ldr r6, [r6, #(IH_NEXT)] /* fetch next handler */
teq r0, #0x00000001 /* Was the irq serviced ? */
/* if it was it'll just fall through this: */
teqne r6, #0x00000000
bne irqchainloop
nextirq:
/* Check for next irq */
rsb r5, r11, #0
ands r10, r11, r5
/* check if there are anymore irq's to service */
bne irqloop
exitirq:
ldmfd sp!, {r2, r3}
ldr r0, Ldisabled_mask
str r2, [r4, #CI_CPL]
str r3, [r0]
bl _C_LABEL(irq_setmasks)
#if __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 r0, [r4, #CI_INTR_DEPTH]
sub r0, r0, #1
str r0, [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 */
ENTRY(irq_setmasks)
/* Disable interrupts */
mrs r3, cpsr_all
orr r1, r3, #(I32_bit)
msr cpsr_all, r1
/* Calculate IOMD interrupt mask */
ldr r1, Lcurrent_mask /* All the enabled interrupts */
ldr r1, [r1]
ldr r0, Lspl_masks /* Block due to current spl level */
ldr r2, Lcurrent_spl_level
ldr r2, [r2]
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
ldr r0, Liomd_base
ldr r0, [r0] /* Point to the IOMD */
strb r1, [r0, #(IOMD_IRQMSKA << 2)] /* Set IRQ mask A */
mov r1, r1, lsr #8
strb r1, [r0, #(IOMD_IRQMSKB << 2)] /* Set IRQ mask B */
mov r1, r1, lsr #8
ldr r2, Larm7500_ioc_found
ldr r2, [r2]
cmp r2, #0
beq skip_setting_extended_DMA_mask
/* only for ARM7500's */
strb r1, [r0, #(IOMD_IRQMSKC << 2)]
mov r1, r1, lsr #8
and r2, r1, #0xef
strb r2, [r0, #(IOMD_IRQMSKD << 2)]
mov r1, r1, lsr #3
and r2, r1, #0x10
strb r2, [r0, #(IOMD_DMAMSK << 2)] /* Set DMA mask */
b continue_setting_masks
skip_setting_extended_DMA_mask:
/* non ARM7500's */
strb r1, [r0, #(IOMD_DMAMSK << 2)] /* Set DMA mask */
continue_setting_masks:
/* Restore old cpsr and exit */
msr cpsr_all, r3
mov pc, lr
Lcnt:
.word _C_LABEL(uvmexp)
Lintrcnt:
.word _C_LABEL(intrcnt)
Lirqhandlers:
.word _C_LABEL(irqhandlers) /* Pointer to array of irqhandlers */
#ifdef IRQSTATS
/* These symbols are used by vmstat */
.text
.global _C_LABEL(_intrnames)
_C_LABEL(_intrnames):
.word _C_LABEL(intrnames)
.data
.globl _C_LABEL(intrnames), _C_LABEL(eintrnames), _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt)
_C_LABEL(intrnames):
.asciz "interrupt 0 "
.asciz "interrupt 1 " /* reserved0 */
.asciz "interrupt 2 "
.asciz "interrupt 3 "
.asciz "interrupt 4 "
.asciz "interrupt 5 "
.asciz "interrupt 6 "
.asciz "interrupt 7 " /* reserved1 */
.asciz "interrupt 8 " /* reserved2 */
.asciz "interrupt 9 "
.asciz "interrupt 10 "
.asciz "interrupt 11 "
.asciz "interrupt 12 "
.asciz "interrupt 13 "
.asciz "interrupt 14 "
.asciz "interrupt 15 "
.asciz "dma channel 0"
.asciz "dma channel 1"
.asciz "dma channel 2"
.asciz "dma channel 3"
.asciz "interrupt 20 "
.asciz "interrupt 21 "
.asciz "reserved 3 "
.asciz "reserved 4 "
.asciz "exp card 0 "
.asciz "exp card 1 "
.asciz "exp card 2 "
.asciz "exp card 3 "
.asciz "exp card 4 "
.asciz "exp card 5 "
.asciz "exp card 6 "
.asciz "exp card 7 "
_C_LABEL(sintrnames):
.asciz "softclock "
.asciz "softnet "
.asciz "softserial "
.asciz "softintr 3 "
.asciz "softintr 4 "
.asciz "softintr 5 "
.asciz "softintr 6 "
.asciz "softintr 7 "
.asciz "softintr 8 "
.asciz "softintr 9 "
.asciz "softintr 10 "
.asciz "softintr 11 "
.asciz "softintr 12 "
.asciz "softintr 13 "
.asciz "softintr 14 "
.asciz "softintr 15 "
.asciz "softintr 16 "
.asciz "softintr 17 "
.asciz "softintr 18 "
.asciz "softintr 19 "
.asciz "softintr 20 "
.asciz "softintr 21 "
.asciz "softintr 22 "
.asciz "softintr 23 "
.asciz "softintr 24 "
.asciz "softintr 25 "
.asciz "softintr 26 "
.asciz "softintr 27 "
.asciz "softintr 28 "
.asciz "softintr 29 "
.asciz "softintr 30 "
.asciz "softintr 31 "
_C_LABEL(eintrnames):
.bss
.align 0
_C_LABEL(intrcnt):
.space 32*4 /* XXX Should be linked to number of interrupts */
_C_LABEL(sintrcnt):
.space 32*4 /* XXX Should be linked to number of interrupts */
_C_LABEL(eintrcnt):
#else /* IRQSTATS */
/* Dummy entries to keep vmstat happy */
.text
.globl _C_LABEL(intrnames), _C_LABEL(eintrnames), _C_LABEL(intrcnt), _C_LABEL(eintrcnt)
_C_LABEL(intrnames):
.long 0
_C_LABEL(eintrnames):
_C_LABEL(intrcnt):
.long 0
_C_LABEL(eintrcnt):
#endif /* IRQSTATS */