/*
* Macintosh interrupts
*
* General design:
* In contrary to the Amiga and Atari platforms, the Mac hardware seems to
* exclusively use the autovector interrupts (the 'generic level0-level7'
* interrupts with exception vectors 0x19-0x1f). The following interrupt levels
* are used:
* 1 - VIA1
* - slot 0: one second interrupt (CA2)
* - slot 1: VBlank (CA1)
* - slot 2: ADB data ready (SR full)
* - slot 3: ADB data (CB2)
* - slot 4: ADB clock (CB1)
* - slot 5: timer 2
* - slot 6: timer 1
* - slot 7: status of IRQ; signals 'any enabled int.'
*
* 2 - VIA2 or RBV
* - slot 0: SCSI DRQ (CA2)
* - slot 1: NUBUS IRQ (CA1) need to read port A to find which
* - slot 2: /EXP IRQ (only on IIci)
* - slot 3: SCSI IRQ (CB2)
* - slot 4: ASC IRQ (CB1)
* - slot 5: timer 2 (not on IIci)
* - slot 6: timer 1 (not on IIci)
* - slot 7: status of IRQ; signals 'any enabled int.'
*
* 2 - OSS (IIfx only?)
* - slot 0: SCSI interrupt
* - slot 1: Sound interrupt
*
* Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
*
* 3 - unused (?)
*
* 4 - SCC (slot number determined by reading RR3 on the SSC itself)
* - slot 1: SCC channel A
* - slot 2: SCC channel B
*
* 5 - unused (?)
* [serial errors or special conditions seem to raise level 6
* interrupts on some models (LC4xx?)]
*
* 6 - off switch (?)
*
* For OSS Macintoshes (IIfx only at this point):
*
* 3 - Nubus interrupt
* - slot 0: Slot $9
* - slot 1: Slot $A
* - slot 2: Slot $B
* - slot 3: Slot $C
* - slot 4: Slot $D
* - slot 5: Slot $E
*
* 4 - SCC IOP
* - slot 1: SCC channel A
* - slot 2: SCC channel B
*
* 5 - ISM IOP (ADB?)
*
* 6 - unused
*
* For PSC Macintoshes (660AV, 840AV):
*
* 3 - PSC level 3
* - slot 0: MACE
*
* 4 - PSC level 4
* - slot 1: SCC channel A interrupt
* - slot 2: SCC channel B interrupt
* - slot 3: MACE DMA
*
* 5 - PSC level 5
*
* 6 - PSC level 6
*
* Finally we have good 'ole level 7, the non-maskable interrupt:
*
* 7 - NMI (programmer's switch on the back of some Macs)
* Also RAM parity error on models which support it (IIc, IIfx?)
*
* The current interrupt logic looks something like this:
*
* - We install dispatchers for the autovector interrupts (1-7). These
* dispatchers are responsible for querying the hardware (the
* VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
* this information a machspec interrupt number is generated by placing the
* index of the interrupt hardware into the low three bits and the original
* autovector interrupt number in the upper 5 bits. The handlers for the
* resulting machspec interrupt are then called.
*
* - Nubus is a special case because its interrupts are hidden behind two
* layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
* which translates to IRQ number 17. In this spot we install _another_
* dispatcher. This dispatcher finds the interrupting slot number (9-F) and
* then forms a new machspec interrupt number as above with the slot number
* minus 9 in the low three bits and the pseudo-level 7 in the upper five
* bits. The handlers for this new machspec interrupt number are then
* called. This puts Nubus interrupts into the range 56-62.
*
* - The Baboon interrupts (used on some PowerBooks) are an even more special
* case. They're hidden behind the Nubus slot $C interrupt thus adding a
* third layer of indirection. Why oh why did the Apple engineers do that?
*
* - We support "fast" and "slow" handlers, just like the Amiga port. The
* fast handlers are called first and with all interrupts disabled. They
* are expected to execute quickly (hence the name). The slow handlers are
* called last with interrupts enabled and the interrupt level restored.
* They must therefore be reentrant.
*
* TODO:
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h> /* for intr_count */
#include <linux/delay.h>
#include <linux/seq_file.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/machw.h>
#include <asm/macintosh.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>
#include <asm/hwtest.h>
#include <asm/errno.h>
#include <asm/macints.h>
#include <asm/irq_regs.h>
#define DEBUG_SPURIOUS
#define SHUTUP_SONIC
/* SCC interrupt mask */
static int scc_mask;
/*
* VIA/RBV hooks
*/
extern void via_init(void);
extern void via_register_interrupts(void);
extern void via_irq_enable(int);
extern void via_irq_disable(int);
extern void via_irq_clear(int);
extern int via_irq_pending(int);
/*
* OSS hooks
*/
extern int oss_present;
extern void oss_init(void);
extern void oss_register_interrupts(void);
extern void oss_irq_enable(int);
extern void oss_irq_disable(int);
extern void oss_irq_clear(int);
extern int oss_irq_pending(int);
/*
* PSC hooks
*/
extern int psc_present;
extern void psc_init(void);
extern void psc_register_interrupts(void);
extern void psc_irq_enable(int);
extern void psc_irq_disable(int);
extern void psc_irq_clear(int);
extern int psc_irq_pending(int);
/*
* IOP hooks
*/
extern void iop_register_interrupts(void);
/*
* Baboon hooks
*/
extern int baboon_present;
extern void baboon_init(void);
extern void baboon_register_interrupts(void);
extern void baboon_irq_enable(int);
extern void baboon_irq_disable(int);
extern void baboon_irq_clear(int);
extern int baboon_irq_pending(int);
/*
* SCC interrupt routines
*/
static void scc_irq_enable(unsigned int);
static void scc_irq_disable(unsigned int);
/*
* console_loglevel determines NMI handler function
*/
irqreturn_t mac_nmi_handler(int, void *);
irqreturn_t mac_debug_handler(int, void *);
/* #define DEBUG_MACINTS */
static void mac_enable_irq(unsigned int irq);
static void mac_disable_irq(unsigned int irq);
static struct irq_controller mac_irq_controller = {
.name = "mac",
.lock = __SPIN_LOCK_UNLOCKED(mac_irq_controller.lock),
.enable = mac_enable_irq,
.disable = mac_disable_irq,
};
void __init mac_init_IRQ(void)
{
#ifdef DEBUG_MACINTS
printk("mac_init_IRQ(): Setting things up...\n");
#endif
scc_mask = 0;
m68k_setup_irq_controller(&mac_irq_controller, IRQ_USER,
NUM_MAC_SOURCES - IRQ_USER);
/* Make sure the SONIC interrupt is cleared or things get ugly */
#ifdef SHUTUP_SONIC
printk("Killing onboard sonic... ");
/* This address should hopefully be mapped already */
if (hwreg_present((void*)(0x50f0a000))) {
*(long *)(0x50f0a014) = 0x7fffL;
*(long *)(0x50f0a010) = 0L;
}
printk("Done.\n");
#endif /* SHUTUP_SONIC */
/*
* Now register the handlers for the master IRQ handlers
* at levels 1-7. Most of the work is done elsewhere.
*/
if (oss_present)
oss_register_interrupts();
else
via_register_interrupts();
if (psc_present)
psc_register_interrupts();
if (baboon_present)
baboon_register_interrupts();
iop_register_interrupts();
request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
mac_nmi_handler);
#ifdef DEBUG_MACINTS
printk("mac_init_IRQ(): Done!\n");
#endif
}
/*
* mac_enable_irq - enable an interrupt source
* mac_disable_irq - disable an interrupt source
* mac_clear_irq - clears a pending interrupt
* mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
*
* These routines are just dispatchers to the VIA/OSS/PSC routines.
*/
static void mac_enable_irq(unsigned int irq)
{
int irq_src = IRQ_SRC(irq);
switch(irq_src) {
case 1:
via_irq_enable(irq);
break;
case 2:
case 7:
if (oss_present)
oss_irq_enable(irq);
else
via_irq_enable(irq);
break;
case 3:
case 4:
case 5:
case 6:
if (psc_present)
psc_irq_enable(irq);
else if (oss_present)
oss_irq_enable(irq);
else if (irq_src == 4)
scc_irq_enable(irq);
break;
case 8:
if (baboon_present)
baboon_irq_enable(irq);
break;
}
}
static void mac_disable_irq(unsigned int irq)
{
int irq_src = IRQ_SRC(irq);
switch(irq_src) {
case 1:
via_irq_disable(irq);
break;
case 2:
case 7:
if (oss_present)
oss_irq_disable(irq);
else
via_irq_disable(irq);
break;
case 3:
case 4:
case 5:
case 6:
if (psc_present)
psc_irq_disable(irq);
else if (oss_present)
oss_irq_disable(irq);
else if (irq_src == 4)
scc_irq_disable(irq);
break;
case 8:
if (baboon_present)
baboon_irq_disable(irq);
break;
}
}
void mac_clear_irq(unsigned int irq)
{
switch(IRQ_SRC(irq)) {
case 1:
via_irq_clear(irq);
break;
case 2:
case 7:
if (oss_present)
oss_irq_clear(irq);
else
via_irq_clear(irq);
break;
case 3:
case 4:
case 5:
case 6:
if (psc_present)
psc_irq_clear(irq);
else if (oss_present)
oss_irq_clear(irq);
break;
case 8:
if (baboon_present)
baboon_irq_clear(irq);
break;
}
}
int mac_irq_pending(unsigned int irq)
{
switch(IRQ_SRC(irq)) {
case 1:
return via_irq_pending(irq);
case 2:
case 7:
if (oss_present)
return oss_irq_pending(irq);
else
return via_irq_pending(irq);
case 3:
case 4:
case 5:
case 6:
if (psc_present)
return psc_irq_pending(irq);
else if (oss_present)
return oss_irq_pending(irq);
}
return 0;
}
EXPORT_SYMBOL(mac_irq_pending);
static int num_debug[8];
irqreturn_t mac_debug_handler(int irq, void *dev_id)
{
if (num_debug[irq] < 10) {
printk("DEBUG: Unexpected IRQ %d\n", irq);
num_debug[irq]++;
}
return IRQ_HANDLED;
}
static int in_nmi;
static volatile int nmi_hold;
irqreturn_t mac_nmi_handler(int irq, void *dev_id)
{
int i;
/*
* generate debug output on NMI switch if 'debug' kernel option given
* (only works with Penguin!)
*/
in_nmi++;
for (i=0; i<100; i++)
udelay(1000);
if (in_nmi == 1) {
nmi_hold = 1;
printk("... pausing, press NMI to resume ...");
} else {
printk(" ok!\n");
nmi_hold = 0;
}
barrier();
while (nmi_hold == 1)
udelay(1000);
if (console_loglevel >= 8) {
#if 0
struct pt_regs *fp = get_irq_regs();
show_state();
printk("PC: %08lx\nSR: %04x SP: %p\n", fp->pc, fp->sr, fp);
printk("d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
fp->d0, fp->d1, fp->d2, fp->d3);
printk("d4: %08lx d5: %08lx a0: %08lx a1: %08lx\n",
fp->d4, fp->d5, fp->a0, fp->a1);
if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
printk("Corrupted stack page\n");
printk("Process %s (pid: %d, stackpage=%08lx)\n",
current->comm, current->pid, current->kernel_stack_page);
if (intr_count == 1)
dump_stack((struct frame *)fp);
#else
/* printk("NMI "); */
#endif
}
in_nmi--;
return IRQ_HANDLED;
}
/*
* Simple routines for masking and unmasking
* SCC interrupts in cases where this can't be
* done in hardware (only the PSC can do that.)
*/
static void scc_irq_enable(unsigned int irq)
{
int irq_idx = IRQ_IDX(irq);
scc_mask |= (1 << irq_idx);
}
static void scc_irq_disable(unsigned int irq)
{
int irq_idx = IRQ_IDX(irq);
scc_mask &= ~(1 << irq_idx);
}
/*
* SCC master interrupt handler. We have to do a bit of magic here
* to figure out what channel gave us the interrupt; putting this
* here is cleaner than hacking it into drivers/char/macserial.c.
*/
void mac_scc_dispatch(int irq, void *dev_id)
{
volatile unsigned char *scc = (unsigned char *) mac_bi_data.sccbase + 2;
unsigned char reg;
unsigned long flags;
/* Read RR3 from the chip. Always do this on channel A */
/* This must be an atomic operation so disable irqs. */
local_irq_save(flags);
*scc = 3;
reg = *scc;
local_irq_restore(flags);
/* Now dispatch. Bits 0-2 are for channel B and */
/* bits 3-5 are for channel A. We can safely */
/* ignore the remaining bits here. */
/* */
/* Note that we're ignoring scc_mask for now. */
/* If we actually mask the ints then we tend to */
/* get hammered by very persistent SCC irqs, */
/* and since they're autovector interrupts they */
/* pretty much kill the system. */
if (reg & 0x38)
m68k_handle_int(IRQ_SCCA);
if (reg & 0x07)
m68k_handle_int(IRQ_SCCB);
}
