// 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);}