1/*
2 *	linux/arch/alpha/kernel/sys_eiger.c
3 *
4 *	Copyright (C) 1995 David A Rusling
5 *	Copyright (C) 1996, 1999 Jay A Estabrook
6 *	Copyright (C) 1998, 1999 Richard Henderson
7 *	Copyright (C) 1999 Iain Grant
8 *
9 * Code supporting the EIGER (EV6+TSUNAMI).
10 */
11
12#include <linux/kernel.h>
13#include <linux/types.h>
14#include <linux/mm.h>
15#include <linux/sched.h>
16#include <linux/pci.h>
17#include <linux/init.h>
18#include <linux/bitops.h>
19
20#include <asm/ptrace.h>
21#include <asm/dma.h>
22#include <asm/irq.h>
23#include <asm/mmu_context.h>
24#include <asm/io.h>
25#include <asm/pci.h>
26#include <asm/pgtable.h>
27#include <asm/core_tsunami.h>
28#include <asm/hwrpb.h>
29#include <asm/tlbflush.h>
30
31#include "proto.h"
32#include "irq_impl.h"
33#include "pci_impl.h"
34#include "machvec_impl.h"
35
36
37/* Note that this interrupt code is identical to TAKARA.  */
38
39/* Note mask bit is true for DISABLED irqs.  */
40static unsigned long cached_irq_mask[2] = { -1, -1 };
41
42static inline void
43eiger_update_irq_hw(unsigned long irq, unsigned long mask)
44{
45	int regaddr;
46
47	mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
48	regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
49	outl(mask & 0xffff0000UL, regaddr);
50}
51
52static inline void
53eiger_enable_irq(struct irq_data *d)
54{
55	unsigned int irq = d->irq;
56	unsigned long mask;
57	mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
58	eiger_update_irq_hw(irq, mask);
59}
60
61static void
62eiger_disable_irq(struct irq_data *d)
63{
64	unsigned int irq = d->irq;
65	unsigned long mask;
66	mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
67	eiger_update_irq_hw(irq, mask);
68}
69
70static struct irq_chip eiger_irq_type = {
71	.name		= "EIGER",
72	.irq_unmask	= eiger_enable_irq,
73	.irq_mask	= eiger_disable_irq,
74	.irq_mask_ack	= eiger_disable_irq,
75};
76
77static void
78eiger_device_interrupt(unsigned long vector)
79{
80	unsigned intstatus;
81
82	/*
83	 * The PALcode will have passed us vectors 0x800 or 0x810,
84	 * which are fairly arbitrary values and serve only to tell
85	 * us whether an interrupt has come in on IRQ0 or IRQ1. If
86	 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
87	 * probably ISA, but PCI interrupts can come through IRQ0
88	 * as well if the interrupt controller isn't in accelerated
89	 * mode.
90	 *
91	 * OTOH, the accelerator thing doesn't seem to be working
92	 * overly well, so what we'll do instead is try directly
93	 * examining the Master Interrupt Register to see if it's a
94	 * PCI interrupt, and if _not_ then we'll pass it on to the
95	 * ISA handler.
96	 */
97
98	intstatus = inw(0x500) & 15;
99	if (intstatus) {
100		/*
101		 * This is a PCI interrupt. Check each bit and
102		 * despatch an interrupt if it's set.
103		 */
104
105		if (intstatus & 8) handle_irq(16+3);
106		if (intstatus & 4) handle_irq(16+2);
107		if (intstatus & 2) handle_irq(16+1);
108		if (intstatus & 1) handle_irq(16+0);
109	} else {
110		isa_device_interrupt(vector);
111	}
112}
113
114static void
115eiger_srm_device_interrupt(unsigned long vector)
116{
117	int irq = (vector - 0x800) >> 4;
118	handle_irq(irq);
119}
120
121static void __init
122eiger_init_irq(void)
123{
124	long i;
125
126	outb(0, DMA1_RESET_REG);
127	outb(0, DMA2_RESET_REG);
128	outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
129	outb(0, DMA2_MASK_REG);
130
131	if (alpha_using_srm)
132		alpha_mv.device_interrupt = eiger_srm_device_interrupt;
133
134	for (i = 16; i < 128; i += 16)
135		eiger_update_irq_hw(i, -1);
136
137	init_i8259a_irqs();
138
139	for (i = 16; i < 128; ++i) {
140		irq_set_chip_and_handler(i, &eiger_irq_type, handle_level_irq);
141		irq_set_status_flags(i, IRQ_LEVEL);
142	}
143}
144
145static int __init
146eiger_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
147{
148	u8 irq_orig;
149
150	/* The SRM console has already calculated out the IRQ value's for
151	   option cards. As this works lets just read in the value already
152	   set and change it to a useable value by Linux.
153
154	   All the IRQ values generated by the console are greater than 90,
155	   so we subtract 80 because it is (90 - allocated ISA IRQ's).  */
156
157	pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);
158
159	return irq_orig - 0x80;
160}
161
162static u8 __init
163eiger_swizzle(struct pci_dev *dev, u8 *pinp)
164{
165	struct pci_controller *hose = dev->sysdata;
166	int slot, pin = *pinp;
167	int bridge_count = 0;
168
169	/* Find the number of backplane bridges.  */
170	int backplane = inw(0x502) & 0x0f;
171
172	switch (backplane)
173	{
174	   case 0x00: bridge_count = 0; break; /* No bridges */
175	   case 0x01: bridge_count = 1; break; /* 1 */
176	   case 0x03: bridge_count = 2; break; /* 2 */
177	   case 0x07: bridge_count = 3; break; /* 3 */
178	   case 0x0f: bridge_count = 4; break; /* 4 */
179	};
180
181	slot = PCI_SLOT(dev->devfn);
182	while (dev->bus->self) {
183		/* Check for built-in bridges on hose 0. */
184		if (hose->index == 0
185		    && (PCI_SLOT(dev->bus->self->devfn)
186			> 20 - bridge_count)) {
187			slot = PCI_SLOT(dev->devfn);
188			break;
189		}
190		/* Must be a card-based bridge.  */
191		pin = pci_swizzle_interrupt_pin(dev, pin);
192
193		/* Move up the chain of bridges.  */
194		dev = dev->bus->self;
195	}
196	*pinp = pin;
197	return slot;
198}
199
200/*
201 * The System Vectors
202 */
203
204struct alpha_machine_vector eiger_mv __initmv = {
205	.vector_name		= "Eiger",
206	DO_EV6_MMU,
207	DO_DEFAULT_RTC,
208	DO_TSUNAMI_IO,
209	.machine_check		= tsunami_machine_check,
210	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
211	.min_io_address		= DEFAULT_IO_BASE,
212	.min_mem_address	= DEFAULT_MEM_BASE,
213	.pci_dac_offset		= TSUNAMI_DAC_OFFSET,
214
215	.nr_irqs		= 128,
216	.device_interrupt	= eiger_device_interrupt,
217
218	.init_arch		= tsunami_init_arch,
219	.init_irq		= eiger_init_irq,
220	.init_rtc		= common_init_rtc,
221	.init_pci		= common_init_pci,
222	.kill_arch		= tsunami_kill_arch,
223	.pci_map_irq		= eiger_map_irq,
224	.pci_swizzle		= eiger_swizzle,
225};
226ALIAS_MV(eiger)
227