1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/alpha/kernel/sys_eiger.c
4 *
5 * Copyright (C) 1995 David A Rusling
6 * Copyright (C) 1996, 1999 Jay A Estabrook
7 * Copyright (C) 1998, 1999 Richard Henderson
8 * Copyright (C) 1999 Iain Grant
9 *
10 * Code supporting the EIGER (EV6+TSUNAMI).
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/mm.h>
16 #include <linux/sched.h>
17 #include <linux/pci.h>
18 #include <linux/init.h>
19 #include <linux/bitops.h>
20
21 #include <asm/ptrace.h>
22 #include <asm/dma.h>
23 #include <asm/irq.h>
24 #include <asm/mmu_context.h>
25 #include <asm/io.h>
26 #include <asm/core_tsunami.h>
27 #include <asm/hwrpb.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 /* Note that this interrupt code is identical to TAKARA. */
37
38 /* Note mask bit is true for DISABLED irqs. */
39 static unsigned long cached_irq_mask[2] = { -1, -1 };
40
41 static inline void
42 eiger_update_irq_hw(unsigned long irq, unsigned long mask)
43 {
44 int regaddr;
45
46 mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
47 regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
48 outl(mask & 0xffff0000UL, regaddr);
49 }
50
51 static inline void
52 eiger_enable_irq(struct irq_data *d)
53 {
54 unsigned int irq = d->irq;
55 unsigned long mask;
56 mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
57 eiger_update_irq_hw(irq, mask);
58 }
59
60 static void
61 eiger_disable_irq(struct irq_data *d)
62 {
63 unsigned int irq = d->irq;
64 unsigned long mask;
65 mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
66 eiger_update_irq_hw(irq, mask);
67 }
68
69 static struct irq_chip eiger_irq_type = {
70 .name = "EIGER",
71 .irq_unmask = eiger_enable_irq,
72 .irq_mask = eiger_disable_irq,
73 .irq_mask_ack = eiger_disable_irq,
74 };
75
76 static void
77 eiger_device_interrupt(unsigned long vector)
78 {
79 unsigned intstatus;
80
81 /*
82 * The PALcode will have passed us vectors 0x800 or 0x810,
83 * which are fairly arbitrary values and serve only to tell
84 * us whether an interrupt has come in on IRQ0 or IRQ1. If
85 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
86 * probably ISA, but PCI interrupts can come through IRQ0
87 * as well if the interrupt controller isn't in accelerated
88 * mode.
89 *
90 * OTOH, the accelerator thing doesn't seem to be working
91 * overly well, so what we'll do instead is try directly
92 * examining the Master Interrupt Register to see if it's a
93 * PCI interrupt, and if _not_ then we'll pass it on to the
94 * ISA handler.
95 */
96
97 intstatus = inw(0x500) & 15;
98 if (intstatus) {
99 /*
100 * This is a PCI interrupt. Check each bit and
101 * despatch an interrupt if it's set.
102 */
103
104 if (intstatus & 8) handle_irq(16+3);
105 if (intstatus & 4) handle_irq(16+2);
106 if (intstatus & 2) handle_irq(16+1);
107 if (intstatus & 1) handle_irq(16+0);
108 } else {
109 isa_device_interrupt(vector);
110 }
111 }
112
113 static void
114 eiger_srm_device_interrupt(unsigned long vector)
115 {
116 int irq = (vector - 0x800) >> 4;
117 handle_irq(irq);
118 }
119
120 static void __init
121 eiger_init_irq(void)
122 {
123 long i;
124
125 outb(0, DMA1_RESET_REG);
126 outb(0, DMA2_RESET_REG);
127 outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
128 outb(0, DMA2_MASK_REG);
129
130 if (alpha_using_srm)
131 alpha_mv.device_interrupt = eiger_srm_device_interrupt;
132
133 for (i = 16; i < 128; i += 16)
134 eiger_update_irq_hw(i, -1);
135
136 init_i8259a_irqs();
137
138 for (i = 16; i < 128; ++i) {
139 irq_set_chip_and_handler(i, &eiger_irq_type, handle_level_irq);
140 irq_set_status_flags(i, IRQ_LEVEL);
141 }
142 }
143
144 static int
145 eiger_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
146 {
147 u8 irq_orig;
148
149 /* The SRM console has already calculated out the IRQ value's for
150 option cards. As this works lets just read in the value already
151 set and change it to a useable value by Linux.
152
153 All the IRQ values generated by the console are greater than 90,
154 so we subtract 80 because it is (90 - allocated ISA IRQ's). */
155
156 pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);
157
158 return irq_orig - 0x80;
159 }
160
161 static u8
162 eiger_swizzle(struct pci_dev *dev, u8 *pinp)
163 {
164 struct pci_controller *hose = dev->sysdata;
165 int slot, pin = *pinp;
166 int bridge_count = 0;
167
168 /* Find the number of backplane bridges. */
169 int backplane = inw(0x502) & 0x0f;
170
171 switch (backplane)
172 {
173 case 0x00: bridge_count = 0; break; /* No bridges */
174 case 0x01: bridge_count = 1; break; /* 1 */
175 case 0x03: bridge_count = 2; break; /* 2 */
176 case 0x07: bridge_count = 3; break; /* 3 */
177 case 0x0f: bridge_count = 4; break; /* 4 */
178 }
179
180 slot = PCI_SLOT(dev->devfn);
181 while (dev->bus->self) {
182 /* Check for built-in bridges on hose 0. */
183 if (hose->index == 0
184 && (PCI_SLOT(dev->bus->self->devfn)
185 > 20 - bridge_count)) {
186 slot = PCI_SLOT(dev->devfn);
187 break;
188 }
189 /* Must be a card-based bridge. */
190 pin = pci_swizzle_interrupt_pin(dev, pin);
191
192 /* Move up the chain of bridges. */
193 dev = dev->bus->self;
194 }
195 *pinp = pin;
196 return slot;
197 }
198
199 /*
200 * The System Vectors
201 */
202
203 struct alpha_machine_vector eiger_mv __initmv = {
204 .vector_name = "Eiger",
205 DO_EV6_MMU,
206 DO_DEFAULT_RTC,
207 DO_TSUNAMI_IO,
208 .machine_check = tsunami_machine_check,
209 .max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
210 .min_io_address = DEFAULT_IO_BASE,
211 .min_mem_address = DEFAULT_MEM_BASE,
212 .pci_dac_offset = TSUNAMI_DAC_OFFSET,
213
214 .nr_irqs = 128,
215 .device_interrupt = eiger_device_interrupt,
216
217 .init_arch = tsunami_init_arch,
218 .init_irq = eiger_init_irq,
219 .init_rtc = common_init_rtc,
220 .init_pci = common_init_pci,
221 .kill_arch = tsunami_kill_arch,
222 .pci_map_irq = eiger_map_irq,
223 .pci_swizzle = eiger_swizzle,
224 };
225 ALIAS_MV(eiger)
226
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