1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC 4 * found on INDY and Indigo2 workstations. 5 * 6 * Copyright (C) 1996 David S. Miller (davem@davemloft.net) 7 * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org) 8 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu) 9 * - Indigo2 changes 10 * - Interrupt handling fixes 11 * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org) 12 */ 13 #include <linux/types.h> 14 #include <linux/init.h> 15 #include <linux/kernel_stat.h> 16 #include <linux/interrupt.h> 17 #include <linux/ftrace.h> 18 19 #include <asm/irq_cpu.h> 20 #include <asm/sgi/hpc3.h> 21 #include <asm/sgi/ip22.h> 22 23 /* So far nothing hangs here */ 24 #undef USE_LIO3_IRQ 25 26 struct sgint_regs *sgint; 27 28 static char lc0msk_to_irqnr[256]; 29 static char lc1msk_to_irqnr[256]; 30 static char lc2msk_to_irqnr[256]; 31 static char lc3msk_to_irqnr[256]; 32 33 extern int ip22_eisa_init(void); 34 35 static void enable_local0_irq(struct irq_data *d) 36 { 37 /* don't allow mappable interrupt to be enabled from setup_irq, 38 * we have our own way to do so */ 39 if (d->irq != SGI_MAP_0_IRQ) 40 sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0)); 41 } 42 43 static void disable_local0_irq(struct irq_data *d) 44 { 45 sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0)); 46 } 47 48 static struct irq_chip ip22_local0_irq_type = { 49 .name = "IP22 local 0", 50 .irq_mask = disable_local0_irq, 51 .irq_unmask = enable_local0_irq, 52 }; 53 54 static void enable_local1_irq(struct irq_data *d) 55 { 56 /* don't allow mappable interrupt to be enabled from setup_irq, 57 * we have our own way to do so */ 58 if (d->irq != SGI_MAP_1_IRQ) 59 sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1)); 60 } 61 62 static void disable_local1_irq(struct irq_data *d) 63 { 64 sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1)); 65 } 66 67 static struct irq_chip ip22_local1_irq_type = { 68 .name = "IP22 local 1", 69 .irq_mask = disable_local1_irq, 70 .irq_unmask = enable_local1_irq, 71 }; 72 73 static void enable_local2_irq(struct irq_data *d) 74 { 75 sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0)); 76 sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2)); 77 } 78 79 static void disable_local2_irq(struct irq_data *d) 80 { 81 sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2)); 82 if (!sgint->cmeimask0) 83 sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0)); 84 } 85 86 static struct irq_chip ip22_local2_irq_type = { 87 .name = "IP22 local 2", 88 .irq_mask = disable_local2_irq, 89 .irq_unmask = enable_local2_irq, 90 }; 91 92 static void enable_local3_irq(struct irq_data *d) 93 { 94 sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1)); 95 sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3)); 96 } 97 98 static void disable_local3_irq(struct irq_data *d) 99 { 100 sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3)); 101 if (!sgint->cmeimask1) 102 sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1)); 103 } 104 105 static struct irq_chip ip22_local3_irq_type = { 106 .name = "IP22 local 3", 107 .irq_mask = disable_local3_irq, 108 .irq_unmask = enable_local3_irq, 109 }; 110 111 static void indy_local0_irqdispatch(void) 112 { 113 u8 mask = sgint->istat0 & sgint->imask0; 114 u8 mask2; 115 int irq; 116 117 if (mask & SGINT_ISTAT0_LIO2) { 118 mask2 = sgint->vmeistat & sgint->cmeimask0; 119 irq = lc2msk_to_irqnr[mask2]; 120 } else 121 irq = lc0msk_to_irqnr[mask]; 122 123 /* 124 * workaround for INT2 bug; if irq == 0, INT2 has seen a fifo full 125 * irq, but failed to latch it into status register 126 */ 127 if (irq) 128 do_IRQ(irq); 129 else 130 do_IRQ(SGINT_LOCAL0 + 0); 131 } 132 133 static void indy_local1_irqdispatch(void) 134 { 135 u8 mask = sgint->istat1 & sgint->imask1; 136 u8 mask2; 137 int irq; 138 139 if (mask & SGINT_ISTAT1_LIO3) { 140 mask2 = sgint->vmeistat & sgint->cmeimask1; 141 irq = lc3msk_to_irqnr[mask2]; 142 } else 143 irq = lc1msk_to_irqnr[mask]; 144 145 /* if irq == 0, then the interrupt has already been cleared */ 146 if (irq) 147 do_IRQ(irq); 148 } 149 150 extern void ip22_be_interrupt(int irq); 151 152 static void __irq_entry indy_buserror_irq(void) 153 { 154 int irq = SGI_BUSERR_IRQ; 155 156 irq_enter(); 157 kstat_incr_irq_this_cpu(irq); 158 ip22_be_interrupt(irq); 159 irq_exit(); 160 } 161 162 static struct irqaction local0_cascade = { 163 .handler = no_action, 164 .flags = IRQF_NO_THREAD, 165 .name = "local0 cascade", 166 }; 167 168 static struct irqaction local1_cascade = { 169 .handler = no_action, 170 .flags = IRQF_NO_THREAD, 171 .name = "local1 cascade", 172 }; 173 174 static struct irqaction buserr = { 175 .handler = no_action, 176 .flags = IRQF_NO_THREAD, 177 .name = "Bus Error", 178 }; 179 180 static struct irqaction map0_cascade = { 181 .handler = no_action, 182 .flags = IRQF_NO_THREAD, 183 .name = "mapable0 cascade", 184 }; 185 186 #ifdef USE_LIO3_IRQ 187 static struct irqaction map1_cascade = { 188 .handler = no_action, 189 .flags = IRQF_NO_THREAD, 190 .name = "mapable1 cascade", 191 }; 192 #define SGI_INTERRUPTS SGINT_END 193 #else 194 #define SGI_INTERRUPTS SGINT_LOCAL3 195 #endif 196 197 extern void indy_8254timer_irq(void); 198 199 /* 200 * IRQs on the INDY look basically (barring software IRQs which we don't use 201 * at all) like: 202 * 203 * MIPS IRQ Source 204 * -------- ------ 205 * 0 Software (ignored) 206 * 1 Software (ignored) 207 * 2 Local IRQ level zero 208 * 3 Local IRQ level one 209 * 4 8254 Timer zero 210 * 5 8254 Timer one 211 * 6 Bus Error 212 * 7 R4k timer (what we use) 213 * 214 * We handle the IRQ according to _our_ priority which is: 215 * 216 * Highest ---- R4k Timer 217 * Local IRQ zero 218 * Local IRQ one 219 * Bus Error 220 * 8254 Timer zero 221 * Lowest ---- 8254 Timer one 222 * 223 * then we just return, if multiple IRQs are pending then we will just take 224 * another exception, big deal. 225 */ 226 227 asmlinkage void plat_irq_dispatch(void) 228 { 229 unsigned int pending = read_c0_status() & read_c0_cause(); 230 231 /* 232 * First we check for r4k counter/timer IRQ. 233 */ 234 if (pending & CAUSEF_IP7) 235 do_IRQ(SGI_TIMER_IRQ); 236 else if (pending & CAUSEF_IP2) 237 indy_local0_irqdispatch(); 238 else if (pending & CAUSEF_IP3) 239 indy_local1_irqdispatch(); 240 else if (pending & CAUSEF_IP6) 241 indy_buserror_irq(); 242 else if (pending & (CAUSEF_IP4 | CAUSEF_IP5)) 243 indy_8254timer_irq(); 244 } 245 246 void __init arch_init_irq(void) 247 { 248 int i; 249 250 /* Init local mask --> irq tables. */ 251 for (i = 0; i < 256; i++) { 252 if (i & 0x80) { 253 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7; 254 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7; 255 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7; 256 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7; 257 } else if (i & 0x40) { 258 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6; 259 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6; 260 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6; 261 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6; 262 } else if (i & 0x20) { 263 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5; 264 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5; 265 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5; 266 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5; 267 } else if (i & 0x10) { 268 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4; 269 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4; 270 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4; 271 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4; 272 } else if (i & 0x08) { 273 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3; 274 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3; 275 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3; 276 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3; 277 } else if (i & 0x04) { 278 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2; 279 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2; 280 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2; 281 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2; 282 } else if (i & 0x02) { 283 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1; 284 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1; 285 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1; 286 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1; 287 } else if (i & 0x01) { 288 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0; 289 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0; 290 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0; 291 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0; 292 } else { 293 lc0msk_to_irqnr[i] = 0; 294 lc1msk_to_irqnr[i] = 0; 295 lc2msk_to_irqnr[i] = 0; 296 lc3msk_to_irqnr[i] = 0; 297 } 298 } 299 300 /* Mask out all interrupts. */ 301 sgint->imask0 = 0; 302 sgint->imask1 = 0; 303 sgint->cmeimask0 = 0; 304 sgint->cmeimask1 = 0; 305 306 /* init CPU irqs */ 307 mips_cpu_irq_init(); 308 309 for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) { 310 struct irq_chip *handler; 311 312 if (i < SGINT_LOCAL1) 313 handler = &ip22_local0_irq_type; 314 else if (i < SGINT_LOCAL2) 315 handler = &ip22_local1_irq_type; 316 else if (i < SGINT_LOCAL3) 317 handler = &ip22_local2_irq_type; 318 else 319 handler = &ip22_local3_irq_type; 320 321 irq_set_chip_and_handler(i, handler, handle_level_irq); 322 } 323 324 /* vector handler. this register the IRQ as non-sharable */ 325 setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade); 326 setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade); 327 setup_irq(SGI_BUSERR_IRQ, &buserr); 328 329 /* cascade in cascade. i love Indy ;-) */ 330 setup_irq(SGI_MAP_0_IRQ, &map0_cascade); 331 #ifdef USE_LIO3_IRQ 332 setup_irq(SGI_MAP_1_IRQ, &map1_cascade); 333 #endif 334 335 #ifdef CONFIG_EISA 336 if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */ 337 ip22_eisa_init(); 338 #endif 339 } 340