1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/sys_jensen.c
4  *
5  *	Copyright (C) 1995 Linus Torvalds
6  *	Copyright (C) 1998, 1999 Richard Henderson
7  *
8  * Code supporting the Jensen.
9  */
10 #define __EXTERN_INLINE
11 #include <asm/io.h>
12 #include <asm/jensen.h>
13 #undef  __EXTERN_INLINE
14 
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/mm.h>
19 #include <linux/sched.h>
20 #include <linux/pci.h>
21 #include <linux/init.h>
22 
23 #include <asm/ptrace.h>
24 
25 #include <asm/dma.h>
26 #include <asm/irq.h>
27 #include <asm/mmu_context.h>
28 #include <asm/tlbflush.h>
29 
30 #include "proto.h"
31 #include "irq_impl.h"
32 #include "pci_impl.h"
33 #include "machvec_impl.h"
34 
35 
36 /*
37  * Jensen is special: the vector is 0x8X0 for EISA interrupt X, and
38  * 0x9X0 for the local motherboard interrupts.
39  *
40  * Note especially that those local interrupts CANNOT be masked,
41  * which causes much of the pain below...
42  *
43  *	0x660 - NMI
44  *
45  *	0x800 - IRQ0  interval timer (not used, as we use the RTC timer)
46  *	0x810 - IRQ1  line printer (duh..)
47  *	0x860 - IRQ6  floppy disk
48  *
49  *	0x900 - COM1
50  *	0x920 - COM2
51  *	0x980 - keyboard
52  *	0x990 - mouse
53  *
54  * PCI-based systems are more sane: they don't have the local
55  * interrupts at all, and have only normal PCI interrupts from
56  * devices.  Happily it's easy enough to do a sane mapping from the
57  * Jensen.
58  *
59  * Note that this means that we may have to do a hardware
60  * "local_op" to a different interrupt than we report to the rest of the
61  * world.
62  */
63 
64 static void
jensen_local_enable(struct irq_data * d)65 jensen_local_enable(struct irq_data *d)
66 {
67 	/* the parport is really hw IRQ 1, silly Jensen.  */
68 	if (d->irq == 7)
69 		i8259a_enable_irq(d);
70 }
71 
72 static void
jensen_local_disable(struct irq_data * d)73 jensen_local_disable(struct irq_data *d)
74 {
75 	/* the parport is really hw IRQ 1, silly Jensen.  */
76 	if (d->irq == 7)
77 		i8259a_disable_irq(d);
78 }
79 
80 static void
jensen_local_mask_ack(struct irq_data * d)81 jensen_local_mask_ack(struct irq_data *d)
82 {
83 	/* the parport is really hw IRQ 1, silly Jensen.  */
84 	if (d->irq == 7)
85 		i8259a_mask_and_ack_irq(d);
86 }
87 
88 static struct irq_chip jensen_local_irq_type = {
89 	.name		= "LOCAL",
90 	.irq_unmask	= jensen_local_enable,
91 	.irq_mask	= jensen_local_disable,
92 	.irq_mask_ack	= jensen_local_mask_ack,
93 };
94 
95 static void
jensen_device_interrupt(unsigned long vector)96 jensen_device_interrupt(unsigned long vector)
97 {
98 	int irq;
99 
100 	switch (vector) {
101 	case 0x660:
102 		printk("Whee.. NMI received. Probable hardware error\n");
103 		printk("61=%02x, 461=%02x\n", inb(0x61), inb(0x461));
104 		return;
105 
106 	/* local device interrupts: */
107 	case 0x900: irq = 4; break;		/* com1 -> irq 4 */
108 	case 0x920: irq = 3; break;		/* com2 -> irq 3 */
109 	case 0x980: irq = 1; break;		/* kbd -> irq 1 */
110 	case 0x990: irq = 9; break;		/* mouse -> irq 9 */
111 
112 	default:
113 		if (vector > 0x900) {
114 			printk("Unknown local interrupt %lx\n", vector);
115 			return;
116 		}
117 
118 		irq = (vector - 0x800) >> 4;
119 		if (irq == 1)
120 			irq = 7;
121 		break;
122 	}
123 
124 	/* If there is no handler yet... */
125 	if (!irq_has_action(irq)) {
126 	    /* If it is a local interrupt that cannot be masked... */
127 	    if (vector >= 0x900)
128 	    {
129 	        /* Clear keyboard/mouse state */
130 	    	inb(0x64);
131 		inb(0x60);
132 		/* Reset serial ports */
133 		inb(0x3fa);
134 		inb(0x2fa);
135 		outb(0x0c, 0x3fc);
136 		outb(0x0c, 0x2fc);
137 		/* Clear NMI */
138 		outb(0,0x61);
139 		outb(0,0x461);
140 	    }
141 	}
142 
143 #if 0
144         /* A useful bit of code to find out if an interrupt is going wild.  */
145         {
146           static unsigned int last_msg = 0, last_cc = 0;
147           static int last_irq = -1, count = 0;
148           unsigned int cc;
149 
150           __asm __volatile("rpcc %0" : "=r"(cc));
151           ++count;
152 #define JENSEN_CYCLES_PER_SEC	(150000000)
153           if (cc - last_msg > ((JENSEN_CYCLES_PER_SEC) * 3) ||
154 	      irq != last_irq) {
155                 printk(KERN_CRIT " irq %d count %d cc %u @ %lx\n",
156                        irq, count, cc-last_cc, get_irq_regs()->pc);
157                 count = 0;
158                 last_msg = cc;
159                 last_irq = irq;
160           }
161           last_cc = cc;
162         }
163 #endif
164 
165 	handle_irq(irq);
166 }
167 
168 static void __init
jensen_init_irq(void)169 jensen_init_irq(void)
170 {
171 	init_i8259a_irqs();
172 
173 	irq_set_chip_and_handler(1, &jensen_local_irq_type, handle_level_irq);
174 	irq_set_chip_and_handler(4, &jensen_local_irq_type, handle_level_irq);
175 	irq_set_chip_and_handler(3, &jensen_local_irq_type, handle_level_irq);
176 	irq_set_chip_and_handler(7, &jensen_local_irq_type, handle_level_irq);
177 	irq_set_chip_and_handler(9, &jensen_local_irq_type, handle_level_irq);
178 
179 	common_init_isa_dma();
180 }
181 
182 static void __init
jensen_init_arch(void)183 jensen_init_arch(void)
184 {
185 	struct pci_controller *hose;
186 #ifdef CONFIG_PCI
187 	static struct pci_dev fake_isa_bridge = { .dma_mask = 0xffffffffUL, };
188 
189 	isa_bridge = &fake_isa_bridge;
190 #endif
191 
192 	/* Create a hose so that we can report i/o base addresses to
193 	   userland.  */
194 
195 	pci_isa_hose = hose = alloc_pci_controller();
196 	hose->io_space = &ioport_resource;
197 	hose->mem_space = &iomem_resource;
198 	hose->index = 0;
199 
200 	hose->sparse_mem_base = EISA_MEM - IDENT_ADDR;
201 	hose->dense_mem_base = 0;
202 	hose->sparse_io_base = EISA_IO - IDENT_ADDR;
203 	hose->dense_io_base = 0;
204 
205 	hose->sg_isa = hose->sg_pci = NULL;
206 	__direct_map_base = 0;
207 	__direct_map_size = 0xffffffff;
208 }
209 
210 static void
jensen_machine_check(unsigned long vector,unsigned long la)211 jensen_machine_check(unsigned long vector, unsigned long la)
212 {
213 	printk(KERN_CRIT "Machine check\n");
214 }
215 
216 /*
217  * The System Vector
218  */
219 
220 struct alpha_machine_vector jensen_mv __initmv = {
221 	.vector_name		= "Jensen",
222 	DO_EV4_MMU,
223 	IO_LITE(JENSEN,jensen),
224 	.machine_check		= jensen_machine_check,
225 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
226 	.rtc_port		= 0x170,
227 
228 	.nr_irqs		= 16,
229 	.device_interrupt	= jensen_device_interrupt,
230 
231 	.init_arch		= jensen_init_arch,
232 	.init_irq		= jensen_init_irq,
233 	.init_rtc		= common_init_rtc,
234 	.init_pci		= NULL,
235 	.kill_arch		= NULL,
236 };
237 ALIAS_MV(jensen)
238