1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/alpha/kernel/sys_alcor.c
4 *
5 * Copyright (C) 1995 David A Rusling
6 * Copyright (C) 1996 Jay A Estabrook
7 * Copyright (C) 1998, 1999 Richard Henderson
8 *
9 * Code supporting the ALCOR and XLT (XL-300/366/433).
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/reboot.h>
19 #include <linux/bitops.h>
20
21 #include <asm/ptrace.h>
22 #include <asm/io.h>
23 #include <asm/dma.h>
24 #include <asm/mmu_context.h>
25 #include <asm/irq.h>
26 #include <asm/core_cia.h>
27 #include <asm/tlbflush.h>
28
29 #include "proto.h"
30 #include "irq_impl.h"
31 #include "pci_impl.h"
32 #include "machvec_impl.h"
33
34
35 /* Note mask bit is true for ENABLED irqs. */
36 static unsigned long cached_irq_mask;
37
38 static inline void
39 alcor_update_irq_hw(unsigned long mask)
40 {
41 *(vuip)GRU_INT_MASK = mask;
42 mb();
43 }
44
45 static inline void
46 alcor_enable_irq(struct irq_data *d)
47 {
48 alcor_update_irq_hw(cached_irq_mask |= 1UL << (d->irq - 16));
49 }
50
51 static void
52 alcor_disable_irq(struct irq_data *d)
53 {
54 alcor_update_irq_hw(cached_irq_mask &= ~(1UL << (d->irq - 16)));
55 }
56
57 static void
58 alcor_mask_and_ack_irq(struct irq_data *d)
59 {
60 alcor_disable_irq(d);
61
62 /* On ALCOR/XLT, need to dismiss interrupt via GRU. */
63 *(vuip)GRU_INT_CLEAR = 1 << (d->irq - 16); mb();
64 *(vuip)GRU_INT_CLEAR = 0; mb();
65 }
66
67 static void
68 alcor_isa_mask_and_ack_irq(struct irq_data *d)
69 {
70 i8259a_mask_and_ack_irq(d);
71
72 /* On ALCOR/XLT, need to dismiss interrupt via GRU. */
73 *(vuip)GRU_INT_CLEAR = 0x80000000; mb();
74 *(vuip)GRU_INT_CLEAR = 0; mb();
75 }
76
77 static struct irq_chip alcor_irq_type = {
78 .name = "ALCOR",
79 .irq_unmask = alcor_enable_irq,
80 .irq_mask = alcor_disable_irq,
81 .irq_mask_ack = alcor_mask_and_ack_irq,
82 };
83
84 static void
85 alcor_device_interrupt(unsigned long vector)
86 {
87 unsigned long pld;
88 unsigned int i;
89
90 /* Read the interrupt summary register of the GRU */
91 pld = (*(vuip)GRU_INT_REQ) & GRU_INT_REQ_BITS;
92
93 /*
94 * Now for every possible bit set, work through them and call
95 * the appropriate interrupt handler.
96 */
97 while (pld) {
98 i = ffz(~pld);
99 pld &= pld - 1; /* clear least bit set */
100 if (i == 31) {
101 isa_device_interrupt(vector);
102 } else {
103 handle_irq(16 + i);
104 }
105 }
106 }
107
108 static void __init
109 alcor_init_irq(void)
110 {
111 long i;
112
113 if (alpha_using_srm)
114 alpha_mv.device_interrupt = srm_device_interrupt;
115
116 *(vuip)GRU_INT_MASK = 0; mb(); /* all disabled */
117 *(vuip)GRU_INT_EDGE = 0; mb(); /* all are level */
118 *(vuip)GRU_INT_HILO = 0x80000000U; mb(); /* ISA only HI */
119 *(vuip)GRU_INT_CLEAR = 0; mb(); /* all clear */
120
121 for (i = 16; i < 48; ++i) {
122 /* On Alcor, at least, lines 20..30 are not connected
123 and can generate spurious interrupts if we turn them
124 on while IRQ probing. */
125 if (i >= 16+20 && i <= 16+30)
126 continue;
127 irq_set_chip_and_handler(i, &alcor_irq_type, handle_level_irq);
128 irq_set_status_flags(i, IRQ_LEVEL);
129 }
130 i8259a_irq_type.irq_ack = alcor_isa_mask_and_ack_irq;
131
132 init_i8259a_irqs();
133 common_init_isa_dma();
134
135 if (request_irq(16 + 31, no_action, 0, "isa-cascade", NULL))
136 pr_err("Failed to register isa-cascade interrupt\n");
137 }
138
139
140 /*
141 * PCI Fixup configuration.
142 *
143 * Summary @ GRU_INT_REQ:
144 * Bit Meaning
145 * 0 Interrupt Line A from slot 2
146 * 1 Interrupt Line B from slot 2
147 * 2 Interrupt Line C from slot 2
148 * 3 Interrupt Line D from slot 2
149 * 4 Interrupt Line A from slot 1
150 * 5 Interrupt line B from slot 1
151 * 6 Interrupt Line C from slot 1
152 * 7 Interrupt Line D from slot 1
153 * 8 Interrupt Line A from slot 0
154 * 9 Interrupt Line B from slot 0
155 *10 Interrupt Line C from slot 0
156 *11 Interrupt Line D from slot 0
157 *12 Interrupt Line A from slot 4
158 *13 Interrupt Line B from slot 4
159 *14 Interrupt Line C from slot 4
160 *15 Interrupt Line D from slot 4
161 *16 Interrupt Line D from slot 3
162 *17 Interrupt Line D from slot 3
163 *18 Interrupt Line D from slot 3
164 *19 Interrupt Line D from slot 3
165 *20-30 Reserved
166 *31 EISA interrupt
167 *
168 * The device to slot mapping looks like:
169 *
170 * Slot Device
171 * 6 built-in TULIP (XLT only)
172 * 7 PCI on board slot 0
173 * 8 PCI on board slot 3
174 * 9 PCI on board slot 4
175 * 10 PCEB (PCI-EISA bridge)
176 * 11 PCI on board slot 2
177 * 12 PCI on board slot 1
178 *
179 *
180 * This two layered interrupt approach means that we allocate IRQ 16 and
181 * above for PCI interrupts. The IRQ relates to which bit the interrupt
182 * comes in on. This makes interrupt processing much easier.
183 */
184
185 static int
186 alcor_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
187 {
188 static char irq_tab[7][5] = {
189 /*INT INTA INTB INTC INTD */
190 /* note: IDSEL 17 is XLT only */
191 {16+13, 16+13, 16+13, 16+13, 16+13}, /* IdSel 17, TULIP */
192 { 16+8, 16+8, 16+9, 16+10, 16+11}, /* IdSel 18, slot 0 */
193 {16+16, 16+16, 16+17, 16+18, 16+19}, /* IdSel 19, slot 3 */
194 {16+12, 16+12, 16+13, 16+14, 16+15}, /* IdSel 20, slot 4 */
195 { -1, -1, -1, -1, -1}, /* IdSel 21, PCEB */
196 { 16+0, 16+0, 16+1, 16+2, 16+3}, /* IdSel 22, slot 2 */
197 { 16+4, 16+4, 16+5, 16+6, 16+7}, /* IdSel 23, slot 1 */
198 };
199 const long min_idsel = 6, max_idsel = 12, irqs_per_slot = 5;
200 return COMMON_TABLE_LOOKUP;
201 }
202
203 static void
204 alcor_kill_arch(int mode)
205 {
206 cia_kill_arch(mode);
207
208 #ifndef ALPHA_RESTORE_SRM_SETUP
209 switch(mode) {
210 case LINUX_REBOOT_CMD_RESTART:
211 /* Who said DEC engineer's have no sense of humor? ;-) */
212 if (alpha_using_srm) {
213 *(vuip) GRU_RESET = 0x0000dead;
214 mb();
215 }
216 break;
217 case LINUX_REBOOT_CMD_HALT:
218 break;
219 case LINUX_REBOOT_CMD_POWER_OFF:
220 break;
221 }
222
223 halt();
224 #endif
225 }
226
227 static void __init
228 alcor_init_pci(void)
229 {
230 struct pci_dev *dev;
231
232 cia_init_pci();
233
234 /*
235 * Now we can look to see if we are really running on an XLT-type
236 * motherboard, by looking for a 21040 TULIP in slot 6, which is
237 * built into XLT and BRET/MAVERICK, but not available on ALCOR.
238 */
239 dev = pci_get_device(PCI_VENDOR_ID_DEC,
240 PCI_DEVICE_ID_DEC_TULIP,
241 NULL);
242 if (dev && dev->devfn == PCI_DEVFN(6,0)) {
243 alpha_mv.sys.cia.gru_int_req_bits = XLT_GRU_INT_REQ_BITS;
244 printk(KERN_INFO "%s: Detected AS500 or XLT motherboard.\n",
245 __func__);
246 }
247 pci_dev_put(dev);
248 }
249
250
251 /*
252 * The System Vectors
253 */
254
255 struct alpha_machine_vector alcor_mv __initmv = {
256 .vector_name = "Alcor",
257 DO_EV5_MMU,
258 DO_DEFAULT_RTC,
259 DO_CIA_IO,
260 .machine_check = cia_machine_check,
261 .max_isa_dma_address = ALPHA_ALCOR_MAX_ISA_DMA_ADDRESS,
262 .min_io_address = EISA_DEFAULT_IO_BASE,
263 .min_mem_address = CIA_DEFAULT_MEM_BASE,
264
265 .nr_irqs = 48,
266 .device_interrupt = alcor_device_interrupt,
267
268 .init_arch = cia_init_arch,
269 .init_irq = alcor_init_irq,
270 .init_rtc = common_init_rtc,
271 .init_pci = alcor_init_pci,
272 .kill_arch = alcor_kill_arch,
273 .pci_map_irq = alcor_map_irq,
274 .pci_swizzle = common_swizzle,
275
276 .sys = { .cia = {
277 .gru_int_req_bits = ALCOR_GRU_INT_REQ_BITS
278 }}
279 };
280 ALIAS_MV(alcor)
281
282 struct alpha_machine_vector xlt_mv __initmv = {
283 .vector_name = "XLT",
284 DO_EV5_MMU,
285 DO_DEFAULT_RTC,
286 DO_CIA_IO,
287 .machine_check = cia_machine_check,
288 .max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
289 .min_io_address = EISA_DEFAULT_IO_BASE,
290 .min_mem_address = CIA_DEFAULT_MEM_BASE,
291
292 .nr_irqs = 48,
293 .device_interrupt = alcor_device_interrupt,
294
295 .init_arch = cia_init_arch,
296 .init_irq = alcor_init_irq,
297 .init_rtc = common_init_rtc,
298 .init_pci = alcor_init_pci,
299 .kill_arch = alcor_kill_arch,
300 .pci_map_irq = alcor_map_irq,
301 .pci_swizzle = common_swizzle,
302
303 .sys = { .cia = {
304 .gru_int_req_bits = XLT_GRU_INT_REQ_BITS
305 }}
306 };
307
308 /* No alpha_mv alias for XLT, since we compile it in unconditionally
309 with ALCOR; setup_arch knows how to cope. */
310
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