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+/*
+ * 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/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>
+
+#define DEBUG_SPURIOUS
+#define SHUTUP_SONIC
+
+/*
+ * The mac_irq_list array is an array of linked lists of irq_node_t nodes.
+ * Each node contains one handler to be called whenever the interrupt
+ * occurs, with fast handlers listed before slow handlers.
+ */
+
+irq_node_t *mac_irq_list[NUM_MAC_SOURCES];
+
+/* 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(int);
+static void scc_irq_disable(int);
+
+/*
+ * console_loglevel determines NMI handler function
+ */
+
+extern irqreturn_t mac_bang(int, void *, struct pt_regs *);
+irqreturn_t mac_nmi_handler(int, void *, struct pt_regs *);
+irqreturn_t mac_debug_handler(int, void *, struct pt_regs *);
+
+/* #define DEBUG_MACINTS */
+
+void mac_init_IRQ(void)
+{
+ int i;
+
+#ifdef DEBUG_MACINTS
+ printk("mac_init_IRQ(): Setting things up...\n");
+#endif
+ /* Initialize the IRQ handler lists. Initially each list is empty, */
+
+ for (i = 0; i < NUM_MAC_SOURCES; i++) {
+ mac_irq_list[i] = NULL;
+ }
+
+ scc_mask = 0;
+
+ /* 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();
+ cpu_request_irq(7, mac_nmi_handler, IRQ_FLG_LOCK, "NMI",
+ mac_nmi_handler);
+#ifdef DEBUG_MACINTS
+ printk("mac_init_IRQ(): Done!\n");
+#endif
+}
+
+/*
+ * Routines to work with irq_node_t's on linked lists lifted from
+ * the Amiga code written by Roman Zippel.
+ */
+
+static inline void mac_insert_irq(irq_node_t **list, irq_node_t *node)
+{
+ unsigned long flags;
+ irq_node_t *cur;
+
+ if (!node->dev_id)
+ printk("%s: Warning: dev_id of %s is zero\n",
+ __FUNCTION__, node->devname);
+
+ local_irq_save(flags);
+
+ cur = *list;
+
+ if (node->flags & IRQ_FLG_FAST) {
+ node->flags &= ~IRQ_FLG_SLOW;
+ while (cur && cur->flags & IRQ_FLG_FAST) {
+ list = &cur->next;
+ cur = cur->next;
+ }
+ } else if (node->flags & IRQ_FLG_SLOW) {
+ while (cur) {
+ list = &cur->next;
+ cur = cur->next;
+ }
+ } else {
+ while (cur && !(cur->flags & IRQ_FLG_SLOW)) {
+ list = &cur->next;
+ cur = cur->next;
+ }
+ }
+
+ node->next = cur;
+ *list = node;
+
+ local_irq_restore(flags);
+}
+
+static inline void mac_delete_irq(irq_node_t **list, void *dev_id)
+{
+ unsigned long flags;
+ irq_node_t *node;
+
+ local_irq_save(flags);
+
+ for (node = *list; node; list = &node->next, node = *list) {
+ if (node->dev_id == dev_id) {
+ *list = node->next;
+ /* Mark it as free. */
+ node->handler = NULL;
+ local_irq_restore(flags);
+ return;
+ }
+ }
+ local_irq_restore(flags);
+ printk ("%s: tried to remove invalid irq\n", __FUNCTION__);
+}
+
+/*
+ * Call all the handlers for a given interrupt. Fast handlers are called
+ * first followed by slow handlers.
+ *
+ * This code taken from the original Amiga code written by Roman Zippel.
+ */
+
+void mac_do_irq_list(int irq, struct pt_regs *fp)
+{
+ irq_node_t *node, *slow_nodes;
+ unsigned long flags;
+
+ kstat_cpu(0).irqs[irq]++;
+
+#ifdef DEBUG_SPURIOUS
+ if (!mac_irq_list[irq] && (console_loglevel > 7)) {
+ printk("mac_do_irq_list: spurious interrupt %d!\n", irq);
+ return;
+ }
+#endif
+
+ /* serve first fast and normal handlers */
+ for (node = mac_irq_list[irq];
+ node && (!(node->flags & IRQ_FLG_SLOW));
+ node = node->next)
+ node->handler(irq, node->dev_id, fp);
+ if (!node) return;
+ local_save_flags(flags);
+ local_irq_restore((flags & ~0x0700) | (fp->sr & 0x0700));
+ /* if slow handlers exists, serve them now */
+ slow_nodes = node;
+ for (; node; node = node->next) {
+ node->handler(irq, node->dev_id, fp);
+ }
+}
+
+/*
+ * 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.
+ */
+
+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;
+ }
+}
+
+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;
+}
+
+/*
+ * Add an interrupt service routine to an interrupt source.
+ * Returns 0 on success.
+ *
+ * FIXME: You can register interrupts on nonexistent source (ie PSC4 on a
+ * non-PSC machine). We should return -EINVAL in those cases.
+ */
+
+int mac_request_irq(unsigned int irq,
+ irqreturn_t (*handler)(int, void *, struct pt_regs *),
+ unsigned long flags, const char *devname, void *dev_id)
+{
+ irq_node_t *node;
+
+#ifdef DEBUG_MACINTS
+ printk ("%s: irq %d requested for %s\n", __FUNCTION__, irq, devname);
+#endif
+
+ if (irq < VIA1_SOURCE_BASE) {
+ return cpu_request_irq(irq, handler, flags, devname, dev_id);
+ }
+
+ if (irq >= NUM_MAC_SOURCES) {
+ printk ("%s: unknown irq %d requested by %s\n",
+ __FUNCTION__, irq, devname);
+ }
+
+ /* Get a node and stick it onto the right list */
+
+ if (!(node = new_irq_node())) return -ENOMEM;
+
+ node->handler = handler;
+ node->flags = flags;
+ node->dev_id = dev_id;
+ node->devname = devname;
+ node->next = NULL;
+ mac_insert_irq(&mac_irq_list[irq], node);
+
+ /* Now enable the IRQ source */
+
+ mac_enable_irq(irq);
+
+ return 0;
+}
+
+/*
+ * Removes an interrupt service routine from an interrupt source.
+ */
+
+void mac_free_irq(unsigned int irq, void *dev_id)
+{
+#ifdef DEBUG_MACINTS
+ printk ("%s: irq %d freed by %p\n", __FUNCTION__, irq, dev_id);
+#endif
+
+ if (irq < VIA1_SOURCE_BASE) {
+ cpu_free_irq(irq, dev_id);
+ return;
+ }
+
+ if (irq >= NUM_MAC_SOURCES) {
+ printk ("%s: unknown irq %d freed\n",
+ __FUNCTION__, irq);
+ return;
+ }
+
+ mac_delete_irq(&mac_irq_list[irq], dev_id);
+
+ /* If the list for this interrupt is */
+ /* empty then disable the source. */
+
+ if (!mac_irq_list[irq]) {
+ mac_disable_irq(irq);
+ }
+}
+
+/*
+ * Generate a pretty listing for /proc/interrupts
+ *
+ * By the time we're called the autovector interrupt list has already been
+ * generated, so we just need to do the machspec interrupts.
+ *
+ * 990506 (jmt) - rewritten to handle chained machspec interrupt handlers.
+ * Also removed display of num_spurious it is already
+ * displayed for us as autovector irq 0.
+ */
+
+int show_mac_interrupts(struct seq_file *p, void *v)
+{
+ int i;
+ irq_node_t *node;
+ char *base;
+
+ /* Don't do Nubus interrupts in this loop; we do them separately */
+ /* below so that we can print slot numbers instead of IRQ numbers */
+
+ for (i = VIA1_SOURCE_BASE ; i < NUM_MAC_SOURCES ; ++i) {
+
+ /* Nonexistant interrupt or nothing registered; skip it. */
+
+ if ((node = mac_irq_list[i]) == NULL) continue;
+ if (node->flags & IRQ_FLG_STD) continue;
+
+ base = "";
+ switch(IRQ_SRC(i)) {
+ case 1: base = "via1";
+ break;
+ case 2: if (oss_present) {
+ base = "oss";
+ } else {
+ base = "via2";
+ }
+ break;
+ case 3:
+ case 4:
+ case 5:
+ case 6: if (psc_present) {
+ base = "psc";
+ } else if (oss_present) {
+ base = "oss";
+ } else {
+ if (IRQ_SRC(i) == 4) base = "scc";
+ }
+ break;
+ case 7: base = "nbus";
+ break;
+ case 8: base = "bbn";
+ break;
+ }
+ seq_printf(p, "%4s %2d: %10u ", base, i, kstat_cpu(0).irqs[i]);
+
+ do {
+ if (node->flags & IRQ_FLG_FAST) {
+ seq_puts(p, "F ");
+ } else if (node->flags & IRQ_FLG_SLOW) {
+ seq_puts(p, "S ");
+ } else {
+ seq_puts(p, " ");
+ }
+ seq_printf(p, "%s\n", node->devname);
+ if ((node = node->next)) {
+ seq_puts(p, " ");
+ }
+ } while(node);
+
+ }
+ return 0;
+}
+
+void mac_default_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+#ifdef DEBUG_SPURIOUS
+ printk("Unexpected IRQ %d on device %p\n", irq, dev_id);
+#endif
+}
+
+static int num_debug[8];
+
+irqreturn_t mac_debug_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+ 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, struct pt_regs *fp)
+{
+ 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
+ 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(int irq) {
+ int irq_idx = IRQ_IDX(irq);
+
+ scc_mask |= (1 << irq_idx);
+}
+
+static void scc_irq_disable(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, struct pt_regs *regs)
+{
+ 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) mac_do_irq_list(IRQ_SCCA, regs);
+ if (reg & 0x07) mac_do_irq_list(IRQ_SCCB, regs);
+}