1 /* 2 * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code 3 * 4 * 5/2/94 Roman Hodek: 5 * Added support for TT interrupts; setup for TT SCU (may someone has 6 * twiddled there and we won't get the right interrupts :-() 7 * 8 * Major change: The device-independent code in m68k/ints.c didn't know 9 * about non-autovec ints yet. It hardcoded the number of possible ints to 10 * 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the 11 * number of possible ints a constant defined in interrupt.h, which is 12 * 47 for the Atari. So we can call request_irq() for all Atari interrupts 13 * just the normal way. Additionally, all vectors >= 48 are initialized to 14 * call trap() instead of inthandler(). This must be changed here, too. 15 * 16 * 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>: 17 * Corrected a bug in atari_add_isr() which rejected all SCC 18 * interrupt sources if there were no TT MFP! 19 * 20 * 12/13/95: New interface functions atari_level_triggered_int() and 21 * atari_register_vme_int() as support for level triggered VME interrupts. 22 * 23 * 02/12/96: (Roman) 24 * Total rewrite of Atari interrupt handling, for new scheme see comments 25 * below. 26 * 27 * 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>: 28 * Added new function atari_unregister_vme_int(), and 29 * modified atari_register_vme_int() as well as IS_VALID_INTNO() 30 * to work with it. 31 * 32 * This file is subject to the terms and conditions of the GNU General Public 33 * License. See the file COPYING in the main directory of this archive 34 * for more details. 35 * 36 */ 37 38 #include <linux/types.h> 39 #include <linux/kernel.h> 40 #include <linux/kernel_stat.h> 41 #include <linux/init.h> 42 #include <linux/seq_file.h> 43 44 #include <asm/system.h> 45 #include <asm/traps.h> 46 47 #include <asm/atarihw.h> 48 #include <asm/atariints.h> 49 #include <asm/atari_stdma.h> 50 #include <asm/irq.h> 51 #include <asm/entry.h> 52 53 54 /* 55 * Atari interrupt handling scheme: 56 * -------------------------------- 57 * 58 * All interrupt source have an internal number (defined in 59 * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP, 60 * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can 61 * be allocated by atari_register_vme_int(). 62 * 63 * Each interrupt can be of three types: 64 * 65 * - SLOW: The handler runs with all interrupts enabled, except the one it 66 * was called by (to avoid reentering). This should be the usual method. 67 * But it is currently possible only for MFP ints, since only the MFP 68 * offers an easy way to mask interrupts. 69 * 70 * - FAST: The handler runs with all interrupts disabled. This should be used 71 * only for really fast handlers, that just do actions immediately 72 * necessary, and let the rest do a bottom half or task queue. 73 * 74 * - PRIORITIZED: The handler can be interrupted by higher-level ints 75 * (greater IPL, no MFP priorities!). This is the method of choice for ints 76 * which should be slow, but are not from a MFP. 77 * 78 * The feature of more than one handler for one int source is still there, but 79 * only applicable if all handers are of the same type. To not slow down 80 * processing of ints with only one handler by the chaining feature, the list 81 * calling function atari_call_irq_list() is only plugged in at the time the 82 * second handler is registered. 83 * 84 * Implementation notes: For fast-as-possible int handling, there are separate 85 * entry points for each type (slow/fast/prio). The assembler handler calls 86 * the irq directly in the usual case, no C wrapper is involved. In case of 87 * multiple handlers, atari_call_irq_list() is registered as handler and calls 88 * in turn the real irq's. To ease access from assembler level to the irq 89 * function pointer and accompanying data, these two are stored in a separate 90 * array, irq_handler[]. The rest of data (type, name) are put into a second 91 * array, irq_param, that is accessed from C only. For each slow interrupt (32 92 * in all) there are separate handler functions, which makes it possible to 93 * hard-code the MFP register address and value, are necessary to mask the 94 * int. If there'd be only one generic function, lots of calculations would be 95 * needed to determine MFP register and int mask from the vector number :-( 96 * 97 * Furthermore, slow ints may not lower the IPL below its previous value 98 * (before the int happened). This is needed so that an int of class PRIO, on 99 * that this int may be stacked, cannot be reentered. This feature is 100 * implemented as follows: If the stack frame format is 1 (throwaway), the int 101 * is not stacked, and the IPL is anded with 0xfbff, resulting in a new level 102 * 2, which still blocks the HSYNC, but no interrupts of interest. If the 103 * frame format is 0, the int is nested, and the old IPL value can be found in 104 * the sr copy in the frame. 105 */ 106 107 #if 0 108 109 #define NUM_INT_SOURCES (8 + NUM_ATARI_SOURCES) 110 111 typedef void (*asm_irq_handler)(void); 112 113 struct irqhandler { 114 irqreturn_t (*handler)(int, void *, struct pt_regs *); 115 void *dev_id; 116 }; 117 118 struct irqparam { 119 unsigned long flags; 120 const char *devname; 121 }; 122 123 /* 124 * Array with irq's and their parameter data. This array is accessed from low 125 * level assembler code, so an element size of 8 allows usage of index scaling 126 * addressing mode. 127 */ 128 static struct irqhandler irq_handler[NUM_INT_SOURCES]; 129 130 /* 131 * This array hold the rest of parameters of int handlers: type 132 * (slow,fast,prio) and the name of the handler. These values are only 133 * accessed from C 134 */ 135 static struct irqparam irq_param[NUM_INT_SOURCES]; 136 137 /* check for valid int number (complex, sigh...) */ 138 #define IS_VALID_INTNO(n) \ 139 ((n) > 0 && \ 140 /* autovec and ST-MFP ok anyway */ \ 141 (((n) < TTMFP_SOURCE_BASE) || \ 142 /* TT-MFP ok if present */ \ 143 ((n) >= TTMFP_SOURCE_BASE && (n) < SCC_SOURCE_BASE && \ 144 ATARIHW_PRESENT(TT_MFP)) || \ 145 /* SCC ok if present and number even */ \ 146 ((n) >= SCC_SOURCE_BASE && (n) < VME_SOURCE_BASE && \ 147 !((n) & 1) && ATARIHW_PRESENT(SCC)) || \ 148 /* greater numbers ok if they are registered VME vectors */ \ 149 ((n) >= VME_SOURCE_BASE && (n) < VME_SOURCE_BASE + VME_MAX_SOURCES && \ 150 free_vme_vec_bitmap & (1 << ((n) - VME_SOURCE_BASE))))) 151 152 153 /* 154 * Here start the assembler entry points for interrupts 155 */ 156 157 #define IRQ_NAME(nr) atari_slow_irq_##nr##_handler(void) 158 159 #define BUILD_SLOW_IRQ(n) \ 160 asmlinkage void IRQ_NAME(n); \ 161 /* Dummy function to allow asm with operands. */ \ 162 void atari_slow_irq_##n##_dummy (void) { \ 163 __asm__ (__ALIGN_STR "\n" \ 164 "atari_slow_irq_" #n "_handler:\t" \ 165 " addl %6,%5\n" /* preempt_count() += HARDIRQ_OFFSET */ \ 166 SAVE_ALL_INT "\n" \ 167 GET_CURRENT(%%d0) "\n" \ 168 " andb #~(1<<(%c3&7)),%a4:w\n" /* mask this interrupt */ \ 169 /* get old IPL from stack frame */ \ 170 " bfextu %%sp@(%c2){#5,#3},%%d0\n" \ 171 " movew %%sr,%%d1\n" \ 172 " bfins %%d0,%%d1{#21,#3}\n" \ 173 " movew %%d1,%%sr\n" /* set IPL = previous value */ \ 174 " addql #1,%a0\n" \ 175 " lea %a1,%%a0\n" \ 176 " pea %%sp@\n" /* push addr of frame */ \ 177 " movel %%a0@(4),%%sp@-\n" /* push handler data */ \ 178 " pea (%c3+8)\n" /* push int number */ \ 179 " movel %%a0@,%%a0\n" \ 180 " jbsr %%a0@\n" /* call the handler */ \ 181 " addql #8,%%sp\n" \ 182 " addql #4,%%sp\n" \ 183 " orw #0x0600,%%sr\n" \ 184 " andw #0xfeff,%%sr\n" /* set IPL = 6 again */ \ 185 " orb #(1<<(%c3&7)),%a4:w\n" /* now unmask the int again */ \ 186 " jbra ret_from_interrupt\n" \ 187 : : "i" (&kstat_cpu(0).irqs[n+8]), "i" (&irq_handler[n+8]), \ 188 "n" (PT_OFF_SR), "n" (n), \ 189 "i" (n & 8 ? (n & 16 ? &tt_mfp.int_mk_a : &mfp.int_mk_a) \ 190 : (n & 16 ? &tt_mfp.int_mk_b : &mfp.int_mk_b)), \ 191 "m" (preempt_count()), "di" (HARDIRQ_OFFSET) \ 192 ); \ 193 for (;;); /* fake noreturn */ \ 194 } 195 196 BUILD_SLOW_IRQ(0); 197 BUILD_SLOW_IRQ(1); 198 BUILD_SLOW_IRQ(2); 199 BUILD_SLOW_IRQ(3); 200 BUILD_SLOW_IRQ(4); 201 BUILD_SLOW_IRQ(5); 202 BUILD_SLOW_IRQ(6); 203 BUILD_SLOW_IRQ(7); 204 BUILD_SLOW_IRQ(8); 205 BUILD_SLOW_IRQ(9); 206 BUILD_SLOW_IRQ(10); 207 BUILD_SLOW_IRQ(11); 208 BUILD_SLOW_IRQ(12); 209 BUILD_SLOW_IRQ(13); 210 BUILD_SLOW_IRQ(14); 211 BUILD_SLOW_IRQ(15); 212 BUILD_SLOW_IRQ(16); 213 BUILD_SLOW_IRQ(17); 214 BUILD_SLOW_IRQ(18); 215 BUILD_SLOW_IRQ(19); 216 BUILD_SLOW_IRQ(20); 217 BUILD_SLOW_IRQ(21); 218 BUILD_SLOW_IRQ(22); 219 BUILD_SLOW_IRQ(23); 220 BUILD_SLOW_IRQ(24); 221 BUILD_SLOW_IRQ(25); 222 BUILD_SLOW_IRQ(26); 223 BUILD_SLOW_IRQ(27); 224 BUILD_SLOW_IRQ(28); 225 BUILD_SLOW_IRQ(29); 226 BUILD_SLOW_IRQ(30); 227 BUILD_SLOW_IRQ(31); 228 229 asm_irq_handler slow_handlers[32] = { 230 [0] = atari_slow_irq_0_handler, 231 [1] = atari_slow_irq_1_handler, 232 [2] = atari_slow_irq_2_handler, 233 [3] = atari_slow_irq_3_handler, 234 [4] = atari_slow_irq_4_handler, 235 [5] = atari_slow_irq_5_handler, 236 [6] = atari_slow_irq_6_handler, 237 [7] = atari_slow_irq_7_handler, 238 [8] = atari_slow_irq_8_handler, 239 [9] = atari_slow_irq_9_handler, 240 [10] = atari_slow_irq_10_handler, 241 [11] = atari_slow_irq_11_handler, 242 [12] = atari_slow_irq_12_handler, 243 [13] = atari_slow_irq_13_handler, 244 [14] = atari_slow_irq_14_handler, 245 [15] = atari_slow_irq_15_handler, 246 [16] = atari_slow_irq_16_handler, 247 [17] = atari_slow_irq_17_handler, 248 [18] = atari_slow_irq_18_handler, 249 [19] = atari_slow_irq_19_handler, 250 [20] = atari_slow_irq_20_handler, 251 [21] = atari_slow_irq_21_handler, 252 [22] = atari_slow_irq_22_handler, 253 [23] = atari_slow_irq_23_handler, 254 [24] = atari_slow_irq_24_handler, 255 [25] = atari_slow_irq_25_handler, 256 [26] = atari_slow_irq_26_handler, 257 [27] = atari_slow_irq_27_handler, 258 [28] = atari_slow_irq_28_handler, 259 [29] = atari_slow_irq_29_handler, 260 [30] = atari_slow_irq_30_handler, 261 [31] = atari_slow_irq_31_handler 262 }; 263 264 asmlinkage void atari_fast_irq_handler( void ); 265 asmlinkage void atari_prio_irq_handler( void ); 266 267 /* Dummy function to allow asm with operands. */ 268 void atari_fast_prio_irq_dummy (void) { 269 __asm__ (__ALIGN_STR "\n" 270 "atari_fast_irq_handler:\n\t" 271 "orw #0x700,%%sr\n" /* disable all interrupts */ 272 "atari_prio_irq_handler:\n\t" 273 "addl %3,%2\n\t" /* preempt_count() += HARDIRQ_OFFSET */ 274 SAVE_ALL_INT "\n\t" 275 GET_CURRENT(%%d0) "\n\t" 276 /* get vector number from stack frame and convert to source */ 277 "bfextu %%sp@(%c1){#4,#10},%%d0\n\t" 278 "subw #(0x40-8),%%d0\n\t" 279 "jpl 1f\n\t" 280 "addw #(0x40-8-0x18),%%d0\n" 281 "1:\tlea %a0,%%a0\n\t" 282 "addql #1,%%a0@(%%d0:l:4)\n\t" 283 "lea irq_handler,%%a0\n\t" 284 "lea %%a0@(%%d0:l:8),%%a0\n\t" 285 "pea %%sp@\n\t" /* push frame address */ 286 "movel %%a0@(4),%%sp@-\n\t" /* push handler data */ 287 "movel %%d0,%%sp@-\n\t" /* push int number */ 288 "movel %%a0@,%%a0\n\t" 289 "jsr %%a0@\n\t" /* and call the handler */ 290 "addql #8,%%sp\n\t" 291 "addql #4,%%sp\n\t" 292 "jbra ret_from_interrupt" 293 : : "i" (&kstat_cpu(0).irqs), "n" (PT_OFF_FORMATVEC), 294 "m" (preempt_count()), "di" (HARDIRQ_OFFSET) 295 ); 296 for (;;); 297 } 298 #endif 299 300 /* 301 * Bitmap for free interrupt vector numbers 302 * (new vectors starting from 0x70 can be allocated by 303 * atari_register_vme_int()) 304 */ 305 static int free_vme_vec_bitmap; 306 307 /* GK: 308 * HBL IRQ handler for Falcon. Nobody needs it :-) 309 * ++andreas: raise ipl to disable further HBLANK interrupts. 310 */ 311 asmlinkage void falcon_hblhandler(void); 312 asm(".text\n" 313 __ALIGN_STR "\n\t" 314 "falcon_hblhandler:\n\t" 315 "orw #0x200,%sp@\n\t" /* set saved ipl to 2 */ 316 "rte"); 317 318 extern void atari_microwire_cmd(int cmd); 319 320 extern int atari_SCC_reset_done; 321 322 static int atari_startup_irq(unsigned int irq) 323 { 324 m68k_irq_startup(irq); 325 atari_turnon_irq(irq); 326 atari_enable_irq(irq); 327 return 0; 328 } 329 330 static void atari_shutdown_irq(unsigned int irq) 331 { 332 atari_disable_irq(irq); 333 atari_turnoff_irq(irq); 334 m68k_irq_shutdown(irq); 335 336 if (irq == IRQ_AUTO_4) 337 vectors[VEC_INT4] = falcon_hblhandler; 338 } 339 340 static struct irq_controller atari_irq_controller = { 341 .name = "atari", 342 .lock = __SPIN_LOCK_UNLOCKED(atari_irq_controller.lock), 343 .startup = atari_startup_irq, 344 .shutdown = atari_shutdown_irq, 345 .enable = atari_enable_irq, 346 .disable = atari_disable_irq, 347 }; 348 349 /* 350 * void atari_init_IRQ (void) 351 * 352 * Parameters: None 353 * 354 * Returns: Nothing 355 * 356 * This function should be called during kernel startup to initialize 357 * the atari IRQ handling routines. 358 */ 359 360 void __init atari_init_IRQ(void) 361 { 362 m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER, NULL); 363 m68k_setup_irq_controller(&atari_irq_controller, 1, NUM_ATARI_SOURCES - 1); 364 365 /* Initialize the MFP(s) */ 366 367 #ifdef ATARI_USE_SOFTWARE_EOI 368 mfp.vec_adr = 0x48; /* Software EOI-Mode */ 369 #else 370 mfp.vec_adr = 0x40; /* Automatic EOI-Mode */ 371 #endif 372 mfp.int_en_a = 0x00; /* turn off MFP-Ints */ 373 mfp.int_en_b = 0x00; 374 mfp.int_mk_a = 0xff; /* no Masking */ 375 mfp.int_mk_b = 0xff; 376 377 if (ATARIHW_PRESENT(TT_MFP)) { 378 #ifdef ATARI_USE_SOFTWARE_EOI 379 tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */ 380 #else 381 tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */ 382 #endif 383 tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ 384 tt_mfp.int_en_b = 0x00; 385 tt_mfp.int_mk_a = 0xff; /* no Masking */ 386 tt_mfp.int_mk_b = 0xff; 387 } 388 389 if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) { 390 scc.cha_a_ctrl = 9; 391 MFPDELAY(); 392 scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */ 393 } 394 395 if (ATARIHW_PRESENT(SCU)) { 396 /* init the SCU if present */ 397 tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and 398 * disable HSYNC interrupts (who 399 * needs them?) MFP and SCC are 400 * enabled in VME mask 401 */ 402 tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */ 403 } else { 404 /* If no SCU and no Hades, the HSYNC interrupt needs to be 405 * disabled this way. (Else _inthandler in kernel/sys_call.S 406 * gets overruns) 407 */ 408 409 if (!MACH_IS_HADES) { 410 vectors[VEC_INT2] = falcon_hblhandler; 411 vectors[VEC_INT4] = falcon_hblhandler; 412 } 413 } 414 415 if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) { 416 /* Initialize the LM1992 Sound Controller to enable 417 the PSG sound. This is misplaced here, it should 418 be in an atasound_init(), that doesn't exist yet. */ 419 atari_microwire_cmd(MW_LM1992_PSG_HIGH); 420 } 421 422 stdma_init(); 423 424 /* Initialize the PSG: all sounds off, both ports output */ 425 sound_ym.rd_data_reg_sel = 7; 426 sound_ym.wd_data = 0xff; 427 } 428 429 430 /* 431 * atari_register_vme_int() returns the number of a free interrupt vector for 432 * hardware with a programmable int vector (probably a VME board). 433 */ 434 435 unsigned long atari_register_vme_int(void) 436 { 437 int i; 438 439 for (i = 0; i < 32; i++) 440 if ((free_vme_vec_bitmap & (1 << i)) == 0) 441 break; 442 443 if (i == 16) 444 return 0; 445 446 free_vme_vec_bitmap |= 1 << i; 447 return VME_SOURCE_BASE + i; 448 } 449 450 451 void atari_unregister_vme_int(unsigned long irq) 452 { 453 if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) { 454 irq -= VME_SOURCE_BASE; 455 free_vme_vec_bitmap &= ~(1 << irq); 456 } 457 } 458 459 460