aboutsummaryrefslogtreecommitdiff
path: root/arch/alpha/kernel/sys_eiger.c
blob: b99ea488d8446139d4fabdaa53dbeeedf51446eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/*
 *	linux/arch/alpha/kernel/sys_eiger.c
 *
 *	Copyright (C) 1995 David A Rusling
 *	Copyright (C) 1996, 1999 Jay A Estabrook
 *	Copyright (C) 1998, 1999 Richard Henderson
 *	Copyright (C) 1999 Iain Grant
 *
 * Code supporting the EIGER (EV6+TSUNAMI).
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/bitops.h>

#include <asm/ptrace.h>
#include <asm/system.h>
#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/pci.h>
#include <asm/pgtable.h>
#include <asm/core_tsunami.h>
#include <asm/hwrpb.h>
#include <asm/tlbflush.h>

#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"


/* Note that this interrupt code is identical to TAKARA.  */

/* Note mask bit is true for DISABLED irqs.  */
static unsigned long cached_irq_mask[2] = { -1, -1 };

static inline void
eiger_update_irq_hw(unsigned long irq, unsigned long mask)
{
	int regaddr;

	mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
	regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
	outl(mask & 0xffff0000UL, regaddr);
}

static inline void
eiger_enable_irq(unsigned int irq)
{
	unsigned long mask;
	mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
	eiger_update_irq_hw(irq, mask);
}

static void
eiger_disable_irq(unsigned int irq)
{
	unsigned long mask;
	mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
	eiger_update_irq_hw(irq, mask);
}

static unsigned int
eiger_startup_irq(unsigned int irq)
{
	eiger_enable_irq(irq);
	return 0; /* never anything pending */
}

static void
eiger_end_irq(unsigned int irq)
{
	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
		eiger_enable_irq(irq);
}

static struct irq_chip eiger_irq_type = {
	.typename	= "EIGER",
	.startup	= eiger_startup_irq,
	.shutdown	= eiger_disable_irq,
	.enable		= eiger_enable_irq,
	.disable	= eiger_disable_irq,
	.ack		= eiger_disable_irq,
	.end		= eiger_end_irq,
};

static void
eiger_device_interrupt(unsigned long vector)
{
	unsigned intstatus;

	/*
	 * The PALcode will have passed us vectors 0x800 or 0x810,
	 * which are fairly arbitrary values and serve only to tell
	 * us whether an interrupt has come in on IRQ0 or IRQ1. If
	 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
	 * probably ISA, but PCI interrupts can come through IRQ0
	 * as well if the interrupt controller isn't in accelerated
	 * mode.
	 *
	 * OTOH, the accelerator thing doesn't seem to be working
	 * overly well, so what we'll do instead is try directly
	 * examining the Master Interrupt Register to see if it's a
	 * PCI interrupt, and if _not_ then we'll pass it on to the
	 * ISA handler.
	 */

	intstatus = inw(0x500) & 15;
	if (intstatus) {
		/*
		 * This is a PCI interrupt. Check each bit and
		 * despatch an interrupt if it's set.
		 */

		if (intstatus & 8) handle_irq(16+3);
		if (intstatus & 4) handle_irq(16+2);
		if (intstatus & 2) handle_irq(16+1);
		if (intstatus & 1) handle_irq(16+0);
	} else {
		isa_device_interrupt(vector);
	}
}

static void
eiger_srm_device_interrupt(unsigned long vector)
{
	int irq = (vector - 0x800) >> 4;
	handle_irq(irq);
}

static void __init
eiger_init_irq(void)
{
	long i;

	outb(0, DMA1_RESET_REG);
	outb(0, DMA2_RESET_REG);
	outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
	outb(0, DMA2_MASK_REG);

	if (alpha_using_srm)
		alpha_mv.device_interrupt = eiger_srm_device_interrupt;

	for (i = 16; i < 128; i += 16)
		eiger_update_irq_hw(i, -1);

	init_i8259a_irqs();

	for (i = 16; i < 128; ++i) {
		irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
		irq_desc[i].chip = &eiger_irq_type;
	}
}

static int __init
eiger_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
	u8 irq_orig;

	/* The SRM console has already calculated out the IRQ value's for
	   option cards. As this works lets just read in the value already
	   set and change it to a useable value by Linux.

	   All the IRQ values generated by the console are greater than 90,
	   so we subtract 80 because it is (90 - allocated ISA IRQ's).  */

	pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);

	return irq_orig - 0x80;
}

static u8 __init
eiger_swizzle(struct pci_dev *dev, u8 *pinp)
{
	struct pci_controller *hose = dev->sysdata;
	int slot, pin = *pinp;
	int bridge_count = 0;

	/* Find the number of backplane bridges.  */
	int backplane = inw(0x502) & 0x0f;

	switch (backplane)
	{
	   case 0x00: bridge_count = 0; break; /* No bridges */
	   case 0x01: bridge_count = 1; break; /* 1 */
	   case 0x03: bridge_count = 2; break; /* 2 */
	   case 0x07: bridge_count = 3; break; /* 3 */
	   case 0x0f: bridge_count = 4; break; /* 4 */
	};

	slot = PCI_SLOT(dev->devfn);
	while (dev->bus->self) {
		/* Check for built-in bridges on hose 0. */
		if (hose->index == 0
		    && (PCI_SLOT(dev->bus->self->devfn)
			> 20 - bridge_count)) {
			slot = PCI_SLOT(dev->devfn);
			break;
		}
		/* Must be a card-based bridge.  */
		pin = pci_swizzle_interrupt_pin(dev, pin);

		/* Move up the chain of bridges.  */
		dev = dev->bus->self;
	}
	*pinp = pin;
	return slot;
}

/*
 * The System Vectors
 */

struct alpha_machine_vector eiger_mv __initmv = {
	.vector_name		= "Eiger",
	DO_EV6_MMU,
	DO_DEFAULT_RTC,
	DO_TSUNAMI_IO,
	.machine_check		= tsunami_machine_check,
	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
	.min_io_address		= DEFAULT_IO_BASE,
	.min_mem_address	= DEFAULT_MEM_BASE,
	.pci_dac_offset		= TSUNAMI_DAC_OFFSET,

	.nr_irqs		= 128,
	.device_interrupt	= eiger_device_interrupt,

	.init_arch		= tsunami_init_arch,
	.init_irq		= eiger_init_irq,
	.init_rtc		= common_init_rtc,
	.init_pci		= common_init_pci,
	.kill_arch		= tsunami_kill_arch,
	.pci_map_irq		= eiger_map_irq,
	.pci_swizzle		= eiger_swizzle,
};
ALIAS_MV(eiger)