// SPDX-License-Identifier: GPL-2.0 /* * 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.' * * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes: * * 3 - unused (?) * * 4 - SCC * * 5 - unused (?) * [serial errors or special conditions seem to raise level 6 * interrupts on some models (LC4xx?)] * * 6 - off switch (?) * * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and * sound out to their own autovector IRQs and gives VIA1 a higher priority: * * 1 - unused (?) * * 3 - on-board SONIC * * 5 - Apple Sound Chip (ASC) * * 6 - VIA1 * * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to * the Quadra (A/UX) mapping: * * 1 - ISM IOP (ADB) * * 2 - SCSI * * 3 - NuBus * * 4 - SCC IOP * * 6 - VIA1 * * 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? * */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/delay.h> #include <asm/irq.h> #include <asm/macintosh.h> #include <asm/macints.h> #include <asm/mac_via.h> #include <asm/mac_psc.h> #include <asm/mac_oss.h> #include <asm/mac_iop.h> #include <asm/mac_baboon.h> #include <asm/hwtest.h> #include <asm/irq_regs.h> #include <asm/processor.h> static unsigned int mac_irq_startup(struct irq_data *); static void mac_irq_shutdown(struct irq_data *); static struct irq_chip mac_irq_chip = { .name = "mac", .irq_enable = mac_irq_enable, .irq_disable = mac_irq_disable, .irq_startup = mac_irq_startup, .irq_shutdown = mac_irq_shutdown, }; static irqreturn_t mac_nmi_handler(int irq, void *dev_id) { static volatile int in_nmi; if (in_nmi) return IRQ_HANDLED; in_nmi = 1; pr_info("Non-Maskable Interrupt\n"); show_registers(get_irq_regs()); in_nmi = 0; return IRQ_HANDLED; } void __init mac_init_IRQ(void) { m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER, NUM_MAC_SOURCES - IRQ_USER); /* * 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) psc_register_interrupts(); if (baboon_present) baboon_register_interrupts(); iop_register_interrupts(); if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI", mac_nmi_handler)) pr_err("Couldn't register NMI\n"); } /* * mac_irq_enable - enable an interrupt source * mac_irq_disable - disable an interrupt source * * These routines are just dispatchers to the VIA/OSS/PSC routines. */ void mac_irq_enable(struct irq_data *data) { int irq = data->irq; int irq_src = IRQ_SRC(irq); switch(irq_src) { case 1: 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) psc_irq_enable(irq); else if (oss_present) oss_irq_enable(irq); break; case 8: if (baboon_present) baboon_irq_enable(irq); break; } } void mac_irq_disable(struct irq_data *data) { int irq = data->irq; int irq_src = IRQ_SRC(irq); switch(irq_src) { case 1: 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) psc_irq_disable(irq); else if (oss_present) oss_irq_disable(irq); break; case 8: if (baboon_present) baboon_irq_disable(irq); break; } } static unsigned int mac_irq_startup(struct irq_data *data) { int irq = data->irq; if (IRQ_SRC(irq) == 7 && !oss_present) via_nubus_irq_startup(irq); else mac_irq_enable(data); return 0; } static void mac_irq_shutdown(struct irq_data *data) { int irq = data->irq; if (IRQ_SRC(irq) == 7 && !oss_present) via_nubus_irq_shutdown(irq); else mac_irq_disable(data); }
