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 #ifdef USE_LIO3_IRQ 163 #define SGI_INTERRUPTS SGINT_END 164 #else 165 #define SGI_INTERRUPTS SGINT_LOCAL3 166 #endif 167 168 extern void indy_8254timer_irq(void); 169 170 /* 171 * IRQs on the INDY look basically (barring software IRQs which we don't use 172 * at all) like: 173 * 174 * MIPS IRQ Source 175 * -------- ------ 176 * 0 Software (ignored) 177 * 1 Software (ignored) 178 * 2 Local IRQ level zero 179 * 3 Local IRQ level one 180 * 4 8254 Timer zero 181 * 5 8254 Timer one 182 * 6 Bus Error 183 * 7 R4k timer (what we use) 184 * 185 * We handle the IRQ according to _our_ priority which is: 186 * 187 * Highest ---- R4k Timer 188 * Local IRQ zero 189 * Local IRQ one 190 * Bus Error 191 * 8254 Timer zero 192 * Lowest ---- 8254 Timer one 193 * 194 * then we just return, if multiple IRQs are pending then we will just take 195 * another exception, big deal. 196 */ 197 198 asmlinkage void plat_irq_dispatch(void) 199 { 200 unsigned int pending = read_c0_status() & read_c0_cause(); 201 202 /* 203 * First we check for r4k counter/timer IRQ. 204 */ 205 if (pending & CAUSEF_IP7) 206 do_IRQ(SGI_TIMER_IRQ); 207 else if (pending & CAUSEF_IP2) 208 indy_local0_irqdispatch(); 209 else if (pending & CAUSEF_IP3) 210 indy_local1_irqdispatch(); 211 else if (pending & CAUSEF_IP6) 212 indy_buserror_irq(); 213 else if (pending & (CAUSEF_IP4 | CAUSEF_IP5)) 214 indy_8254timer_irq(); 215 } 216 217 void __init arch_init_irq(void) 218 { 219 int i; 220 221 /* Init local mask --> irq tables. */ 222 for (i = 0; i < 256; i++) { 223 if (i & 0x80) { 224 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7; 225 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7; 226 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7; 227 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7; 228 } else if (i & 0x40) { 229 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6; 230 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6; 231 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6; 232 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6; 233 } else if (i & 0x20) { 234 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5; 235 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5; 236 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5; 237 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5; 238 } else if (i & 0x10) { 239 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4; 240 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4; 241 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4; 242 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4; 243 } else if (i & 0x08) { 244 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3; 245 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3; 246 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3; 247 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3; 248 } else if (i & 0x04) { 249 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2; 250 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2; 251 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2; 252 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2; 253 } else if (i & 0x02) { 254 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1; 255 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1; 256 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1; 257 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1; 258 } else if (i & 0x01) { 259 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0; 260 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0; 261 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0; 262 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0; 263 } else { 264 lc0msk_to_irqnr[i] = 0; 265 lc1msk_to_irqnr[i] = 0; 266 lc2msk_to_irqnr[i] = 0; 267 lc3msk_to_irqnr[i] = 0; 268 } 269 } 270 271 /* Mask out all interrupts. */ 272 sgint->imask0 = 0; 273 sgint->imask1 = 0; 274 sgint->cmeimask0 = 0; 275 sgint->cmeimask1 = 0; 276 277 /* init CPU irqs */ 278 mips_cpu_irq_init(); 279 280 for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) { 281 struct irq_chip *handler; 282 283 if (i < SGINT_LOCAL1) 284 handler = &ip22_local0_irq_type; 285 else if (i < SGINT_LOCAL2) 286 handler = &ip22_local1_irq_type; 287 else if (i < SGINT_LOCAL3) 288 handler = &ip22_local2_irq_type; 289 else 290 handler = &ip22_local3_irq_type; 291 292 irq_set_chip_and_handler(i, handler, handle_level_irq); 293 } 294 295 /* vector handler. this register the IRQ as non-sharable */ 296 if (request_irq(SGI_LOCAL_0_IRQ, no_action, IRQF_NO_THREAD, 297 "local0 cascade", NULL)) 298 pr_err("Failed to register local0 cascade interrupt\n"); 299 if (request_irq(SGI_LOCAL_1_IRQ, no_action, IRQF_NO_THREAD, 300 "local1 cascade", NULL)) 301 pr_err("Failed to register local1 cascade interrupt\n"); 302 if (request_irq(SGI_BUSERR_IRQ, no_action, IRQF_NO_THREAD, 303 "Bus Error", NULL)) 304 pr_err("Failed to register Bus Error interrupt\n"); 305 306 /* cascade in cascade. i love Indy ;-) */ 307 if (request_irq(SGI_MAP_0_IRQ, no_action, IRQF_NO_THREAD, 308 "mapable0 cascade", NULL)) 309 pr_err("Failed to register mapable0 cascade interrupt\n"); 310 #ifdef USE_LIO3_IRQ 311 if (request_irq(SGI_MAP_1_IRQ, no_action, IRQF_NO_THREAD, 312 "mapable1 cascade", NULL)) 313 pr_err("Failed to register mapable1 cascade interrupt\n"); 314 #endif 315 316 #ifdef CONFIG_EISA 317 if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */ 318 ip22_eisa_init(); 319 #endif 320 } 321