aboutsummaryrefslogtreecommitdiffstats
path: root/arch/alpha/kernel/sys_eb64p.c
blob: a7a23b40eec53f9319e4502c30d7b99557d71a72 (plain) (blame)
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
/*
 *	linux/arch/alpha/kernel/sys_eb64p.c
 *
 *	Copyright (C) 1995 David A Rusling
 *	Copyright (C) 1996 Jay A Estabrook
 *	Copyright (C) 1998, 1999 Richard Henderson
 *
 * Code supporting the EB64+ and EB66.
 */

#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/pgtable.h>
#include <asm/core_apecs.h>
#include <asm/core_lca.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 mask bit is true for DISABLED irqs.  */
static unsigned int cached_irq_mask = -1;

static inline void
eb64p_update_irq_hw(unsigned int irq, unsigned long mask)
{
	outb(mask >> (irq >= 24 ? 24 : 16), (irq >= 24 ? 0x27 : 0x26));
}

static inline void
eb64p_enable_irq(struct irq_data *d)
{
	eb64p_update_irq_hw(d->irq, cached_irq_mask &= ~(1 << d->irq));
}

static void
eb64p_disable_irq(struct irq_data *d)
{
	eb64p_update_irq_hw(d->irq, cached_irq_mask |= 1 << d->irq);
}

static struct irq_chip eb64p_irq_type = {
	.name		= "EB64P",
	.irq_unmask	= eb64p_enable_irq,
	.irq_mask	= eb64p_disable_irq,
	.irq_mask_ack	= eb64p_disable_irq,
};

static void 
eb64p_device_interrupt(unsigned long vector)
{
	unsigned long pld;
	unsigned int i;

	/* Read the interrupt summary registers */
	pld = inb(0x26) | (inb(0x27) << 8);

	/*
	 * Now, for every possible bit set, work through
	 * them and call the appropriate interrupt handler.
	 */
	while (pld) {
		i = ffz(~pld);
		pld &= pld - 1;	/* clear least bit set */

		if (i == 5) {
			isa_device_interrupt(vector);
		} else {
			handle_irq(16 + i);
		}
	}
}

static void __init
eb64p_init_irq(void)
{
	long i;

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_CABRIOLET)
	/*
	 * CABRIO SRM may not set variation correctly, so here we test
	 * the high word of the interrupt summary register for the RAZ
	 * bits, and hope that a true EB64+ would read all ones...
	 */
	if (inw(0x806) != 0xffff) {
		extern struct alpha_machine_vector cabriolet_mv;

		printk("Detected Cabriolet: correcting HWRPB.\n");

		hwrpb->sys_variation |= 2L << 10;
		hwrpb_update_checksum(hwrpb);

		alpha_mv = cabriolet_mv;
		alpha_mv.init_irq();
		return;
	}
#endif /* GENERIC */

	outb(0xff, 0x26);
	outb(0xff, 0x27);

	init_i8259a_irqs();

	for (i = 16; i < 32; ++i) {
		irq_set_chip_and_handler(i, &eb64p_irq_type, handle_level_irq);
		irq_set_status_flags(i, IRQ_LEVEL);
	}

	common_init_isa_dma();
	setup_irq(16+5, &isa_cascade_irqaction);
}

/*
 * PCI Fixup configuration.
 *
 * There are two 8 bit external summary registers as follows:
 *
 * Summary @ 0x26:
 * Bit      Meaning
 * 0        Interrupt Line A from slot 0
 * 1        Interrupt Line A from slot 1
 * 2        Interrupt Line B from slot 0
 * 3        Interrupt Line B from slot 1
 * 4        Interrupt Line C from slot 0
 * 5        Interrupt line from the two ISA PICs
 * 6        Tulip
 * 7        NCR SCSI
 *
 * Summary @ 0x27
 * Bit      Meaning
 * 0        Interrupt Line C from slot 1
 * 1        Interrupt Line D from slot 0
 * 2        Interrupt Line D from slot 1
 * 3        RAZ
 * 4        RAZ
 * 5        RAZ
 * 6        RAZ
 * 7        RAZ
 *
 * The device to slot mapping looks like:
 *
 * Slot     Device
 *  5       NCR SCSI controller
 *  6       PCI on board slot 0
 *  7       PCI on board slot 1
 *  8       Intel SIO PCI-ISA bridge chip
 *  9       Tulip - DECchip 21040 Ethernet controller
 *   
 *
 * This two layered interrupt approach means that we allocate IRQ 16 and 
 * above for PCI interrupts.  The IRQ relates to which bit the interrupt
 * comes in on.  This makes interrupt processing much easier.
 */

static int __init
eb64p_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
	static char irq_tab[5][5] __initdata = {
		/*INT  INTA  INTB  INTC   INTD */
		{16+7, 16+7, 16+7, 16+7,  16+7},  /* IdSel 5,  slot ?, ?? */
		{16+0, 16+0, 16+2, 16+4,  16+9},  /* IdSel 6,  slot ?, ?? */
		{16+1, 16+1, 16+3, 16+8, 16+10},  /* IdSel 7,  slot ?, ?? */
		{  -1,   -1,   -1,   -1,    -1},  /* IdSel 8,  SIO */
		{16+6, 16+6, 16+6, 16+6,  16+6},  /* IdSel 9,  TULIP */
	};
	const long min_idsel = 5, max_idsel = 9, irqs_per_slot = 5;
	return COMMON_TABLE_LOOKUP;
}


/*
 * The System Vector
 */

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_EB64P)
struct alpha_machine_vector eb64p_mv __initmv = {
	.vector_name		= "EB64+",
	DO_EV4_MMU,
	DO_DEFAULT_RTC,
	DO_APECS_IO,
	.machine_check		= apecs_machine_check,
	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
	.min_io_address		= DEFAULT_IO_BASE,
	.min_mem_address	= APECS_AND_LCA_DEFAULT_MEM_BASE,

	.nr_irqs		= 32,
	.device_interrupt	= eb64p_device_interrupt,

	.init_arch		= apecs_init_arch,
	.init_irq		= eb64p_init_irq,
	.init_rtc		= common_init_rtc,
	.init_pci		= common_init_pci,
	.kill_arch		= NULL,
	.pci_map_irq		= eb64p_map_irq,
	.pci_swizzle		= common_swizzle,
};
ALIAS_MV(eb64p)
#endif

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_EB66)
struct alpha_machine_vector eb66_mv __initmv = {
	.vector_name		= "EB66",
	DO_EV4_MMU,
	DO_DEFAULT_RTC,
	DO_LCA_IO,
	.machine_check		= lca_machine_check,
	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
	.min_io_address		= DEFAULT_IO_BASE,
	.min_mem_address	= APECS_AND_LCA_DEFAULT_MEM_BASE,

	.nr_irqs		= 32,
	.device_interrupt	= eb64p_device_interrupt,

	.init_arch		= lca_init_arch,
	.init_irq		= eb64p_init_irq,
	.init_rtc		= common_init_rtc,
	.init_pci		= common_init_pci,
	.pci_map_irq		= eb64p_map_irq,
	.pci_swizzle		= common_swizzle,
};
ALIAS_MV(eb66)
#endif