NetBSD/sys/arch/evbarm/ifpga/ifpga_irq.S

556 lines
14 KiB
ArmAsm

/* $NetBSD: ifpga_irq.S,v 1.2 2001/10/29 14:23:35 rearnsha Exp $
/*
* Copyright (c) 1998 Mark Brinicombe.
* Copyright (c) 1998 Causality Limited
* All rights reserved.
*
* 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 OR CONTRIBUTORS 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.
*/
#include "opt_irqstats.h"
#include "assym.h"
#include <machine/asm.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <evbarm/ifpga/ifpgamem.h>
#include <evbarm/ifpga/ifpgareg.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 register in the 21285
* and then calls the installed handlers 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.
*/
Lintr_disabled_mask:
.word _C_LABEL(intr_disabled_mask)
Lintr_claimed_mask:
.word _C_LABEL(intr_claimed_mask)
Lcurrent_spl_level:
.word _C_LABEL(current_spl_level)
Lcurrent_intr_depth:
.word _C_LABEL(current_intr_depth)
.word _C_LABEL(prev_intr_depth)
Lspl_masks:
.word _C_LABEL(spl_masks)
Lirq_vbase:
.word _C_LABEL(ifpga_irq_vbase)
/*
* Register usage
*
* 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.
*/
ASENTRY_NP(irq_entry)
sub lr, lr, #0x00000004 /* Adjust the lr */
PUSHFRAMEINSVC /* Push an interrupt frame */
/*
* 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, Lcurrent_intr_depth
ldr r2, Lcurrent_intr_depth+4
ldr r1, [r0]
str r1, [r2]
add r1, r1, #1
str r1, [r0]
/* Load r8 with the IFPGA interrupt requests */
ldr r10, Lirq_vbase
ldr r10, [r10]
ldr r8, [r10, #(IFPGA_INTR_STATUS)]
/* This condition needs further examination */
teq r8, #0
beq irq_unknown
/* Block the current requested interrupts */
ldr r1, Lintr_disabled_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, #(_SPL_LEVELS - 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] /* store new disabled mask */
ldr r2, Lcurrent_spl_level
ldr r1, [r2]
str r9, [r2]
stmfd sp!, {r1}
ldr r7, Lintr_claimed_mask /* get claimed mask */
ldr r6, [r7]
bic r6, r6, r0 /* mask out disabled */
ldr r7, Lintr_current_mask /* get claimed mask */
str r6, [r7] /* new current mask */
ldr r7, Lirq_vbase
/* Update the IFPGA irq masks */
bl _C_LABEL(irq_setmasks_nointr)
ldr r7, [r7] /* Ensure irq pin has time to update */
Lstill_pending:
ldr r0, [r7, #(IFPGA_INTR_STATUS)]
tst r0, r8
bne Lstill_pending
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 mask so we can alter it */
mov r11, r8
/* ffs routine to find first irq to service */
/* standard trick to isolate bottom bit in a0 or 0 if a0 = 0 on entry */
rsb r4, r11, #0
ands r10, r11, r4
/*
* now r10 has at most 1 set bit, call this X
* if X = 0, branch to exit code
*/
beq exitirq
adr r5, Lirq_ffs_table
irqloop:
/*
* 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 r4, Lcnt /* Stat info A */
ldr r6, [r7, r9, lsl #2] /* Get address of first handler structure */
ldr r1, [r4, #(V_INTR)] /* Stat info B */
teq r6, #0x00000000 /* Do we have a handler */
moveq r0, r8 /* IRQ requests as arg 0 */
addeq lr, pc, #nextirq - . - 8 /* return address */
bic r11, r11, r10 /* clear the IRQ bit */
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
#ifdef IRQSTATS
ldr r3, [r2, r3, lsl #2]!
#endif
/* stat info D */
str r1, [r4, #(V_INTR)]
#ifdef IRQSTATS
add r3, r3, #0x00000001
str r3, [r2]
#endif /* IRQSTATS */
irqchainloop:
ldr r0, [r6, #(IH_ARG)] /* Get argument pointer */
add lr, pc, #nextinchain - . - 8 /* return address */
teq r0, #0x00000000 /* If arg is zero pass stack frame */
addeq r0, sp, #8 /* ... stack frame [XXX needs care] */
ldr pc, [r6, #(IH_FUNC)] /* Call handler */
nextinchain:
ldr r6, [r6, #(IH_NEXT)] /* fetch next handler */
#if 0
teq r0, #0x00000001 /* Was the irq serviced ? */
#endif
/* if it was it'll just fall through this: */
teq r6, #0x00000000
bne irqchainloop
nextirq:
/* Check for next irq */
rsb r4, r11, #0
ands r10, r11, r4
/* check if there are anymore irq's to service */
bne irqloop
exitirq:
ldmfd sp!, {r2, r3}
ldr r1, Lcurrent_spl_level
ldr r9, Lintr_disabled_mask
ldr r7, Lspl_masks
ldr r8, Lspl_mask
ldr r7, [r7, r2, lsl #2] /* Mask for new spl level */
str r2, [r1] /* store current spl level */
str r7, [r8] /* Restore the spl_mask */
ldr r1, Lintr_claimed_mask /* get claimed mask */
str r3, [r9] /* store disabled mask */
ldr r0, [r1]
ldr r9, Lintr_current_mask /* get claimed mask */
bic r0, r0, r3 /* mask out disabled */
str r0, [r9] /* new current mask */
bl _C_LABEL(irq_setmasks)
bl _C_LABEL(dosoftints) /* Handle the soft interrupts */
/* Manage AST's. Maybe this should be done as a soft interrupt ? */
ldr r0, [sp] /* Get the SPSR from stack */
and r0, r0, #(PSR_MODE) /* Test for USR32 mode before the IRQ */
teq r0, #(PSR_USR32_MODE)
ldreq r0, Lastpending /* Do we have an AST pending ? */
ldreq r1, [r0]
teqeq r1, #0x00000001
beq irqast /* call the AST handler */
/* Kill IRQ's in preparation for exit */
mrs r0, cpsr_all
orr r0, r0, #(I32_bit)
msr cpsr_all, r0
irq_unknown:
/* Decrement the nest count */
ldr r0, Lcurrent_intr_depth
ldr r2, Lcurrent_intr_depth+4
ldr r1, [r0]
str r1, [r2]
sub r1, r1, #1
str r1, [r0]
PULLFRAMEFROMSVCANDEXIT
movs pc, lr /* Exit */
/*
* Ok, snag with current intr depth ...
* If ast() calls mi_sleep() the current_intr_depth will not be
* decremented until the process is woken up. This can result
* in the system believing it is still in the interrupt handler.
* If we are calling ast() then correct the current_intr_depth
* before the call.
*/
irqast:
mov r1, #0x00000000 /* Clear ast_pending */
str r1, [r0]
/* Kill IRQ's so we atomically decrement current_intr_depth */
mrs r2, cpsr_all
orr r3, r2, #(I32_bit)
msr cpsr_all, r3
/* Decrement the nest count */
ldr r0, Lcurrent_intr_depth
ldr r4, Lcurrent_intr_depth+4
ldr r1, [r0]
str r1, [r4]
sub r1, r1, #1
str r1, [r0]
/* Restore IRQ's */
msr cpsr_all, r2
mov r0, sp
bl _C_LABEL(ast)
/* Kill IRQ's in preparation for exit */
mrs r0, cpsr_all
orr r0, r0, #(I32_bit)
msr cpsr_all, r0
PULLFRAMEFROMSVCANDEXIT
movs pc, lr /* Exit */
Lcnt:
.word _C_LABEL(uvmexp)
Lintrcnt:
.word _C_LABEL(intrcnt)
Lirqhandlers:
.word _C_LABEL(irqhandlers) /* Pointer to array of irqhandlers */
Lastpending:
.word _C_LABEL(astpending)
Lspl_mask:
.word _C_LABEL(spl_mask) /* irq's allowed at current spl level */
Lintr_current_mask:
.word _C_LABEL(intr_current_mask)
ENTRY(irq_setmasks)
/* Disable interrupts */
mrs r3, cpsr_all
orr r1, r3, #(I32_bit)
msr cpsr_all, r1
/* Calculate IFPGA interrupt mask */
ldr r1, Lintr_current_mask /* All the enabled interrupts */
ldr r2, Lspl_mask /* Block due to current spl level */
ldr r0, Lirq_vbase /* Virtual address of irq ctrlr */
ldr r1, [r1]
ldr r2, [r2]
ldr r0, [r0]
and r1, r1, r2
str r1, [r0, #(IFPGA_INTR_ENABLESET)]
mvn r1, r1
str r1, [r0, #(IFPGA_INTR_ENABLECLR)]
/* Restore old cpsr and exit */
msr cpsr_all, r3
mov pc, lr
ENTRY(irq_setmasks_nointr)
/* Calculate IFPGA interrupt mask */
ldr r1, Lintr_current_mask /* All the enabled interrupts */
ldr r2, Lspl_mask /* Block due to current spl level */
ldr r0, Lirq_vbase
ldr r1, [r1]
ldr r2, [r2]
ldr r0, [r0]
and r1, r1, r2
str r1, [r0, #(IFPGA_INTR_ENABLESET)]
mvn r1, r1
str r1, [r0, #(IFPGA_INTR_ENABLECLR)]
mov pc, lr
.data
.align 0
.global _C_LABEL(prev_intr_depth)
_C_LABEL(prev_intr_depth):
.word 0
#ifdef IRQSTATS
/* These symbols are used by vmstat */
.text
.global _C_LABEL(_intrnames)
_C_LABEL(_intrnames):
.word _C_LABEL(intrnames)
.data
.align 0
.global _C_LABEL(intrnames), _C_LABEL(sintrnames), _C_LABEL(eintrnames)
.global _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt)
_C_LABEL(intrnames):
.asciz "interrupt 0 "
.asciz "interrupt 1 "
.asciz "interrupt 2 "
.asciz "interrupt 3 "
.asciz "interrupt 4 "
.asciz "interrupt 5 "
.asciz "interrupt 6 "
.asciz "interrupt 7 "
.asciz "interrupt 8 "
.asciz "interrupt 9 "
.asciz "interrupt 10 "
.asciz "interrupt 11 "
.asciz "interrupt 12 "
.asciz "interrupt 13 "
.asciz "interrupt 14 "
.asciz "interrupt 15 "
.asciz "interrupt 16 "
.asciz "interrupt 17 "
.asciz "interrupt 18 "
.asciz "interrupt 19 "
.asciz "interrupt 20 "
.asciz "interrupt 21 "
.asciz "interrupt 22 "
.asciz "interrupt 23 "
.asciz "interrupt 24 "
.asciz "interrupt 25 "
.asciz "interrupt 26 "
.asciz "interrupt 27 "
.asciz "interrupt 28 "
.asciz "interrupt 29 "
.asciz "interrupt 30 "
.asciz "interrupt 31 "
_C_LABEL(sintrnames):
.asciz "soft int 0 "
.asciz "soft int 1 "
.asciz "soft int 2 "
.asciz "soft int 3 "
.asciz "soft int 4 "
.asciz "soft int 5 "
.asciz "soft int 6 "
.asciz "soft int 7 "
.asciz "soft int 8 "
.asciz "soft int 9 "
.asciz "soft int 10 "
.asciz "soft int 11 "
.asciz "soft int 12 "
.asciz "soft int 13 "
.asciz "soft int 14 "
.asciz "soft int 15 "
.asciz "soft int 16 "
.asciz "soft int 17 "
.asciz "soft int 18 "
.asciz "soft int 19 "
.asciz "soft int 20 "
.asciz "soft int 21 "
.asciz "soft int 22 "
.asciz "soft int 23 "
.asciz "soft int 24 "
.asciz "soft int 25 "
.asciz "soft int 26 "
.asciz "soft int 27 "
.asciz "soft int 28 "
.asciz "soft int 29 "
.asciz "soft int 30 "
.asciz "soft int 31 "
_C_LABEL(eintrnames):
.bss
.align 0
.global _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt)
_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 soft ints */
_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 */