iomd_irq.S revision 1.4
1 /* $NetBSD: iomd_irq.S,v 1.4 2003/11/05 21:10:59 scw Exp $ */ 2 3 /* 4 * Copyright (c) 1994-1998 Mark Brinicombe. 5 * Copyright (c) 1994 Brini. 6 * All rights reserved. 7 * 8 * This code is derived from software written for Brini by Mark Brinicombe 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by Mark Brinicombe 21 * for the NetBSD Project. 22 * 4. The name of the company nor the name of the author may be used to 23 * endorse or promote products derived from this software without specific 24 * prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Low level irq and fiq handlers 38 * 39 * Created : 27/09/94 40 */ 41 42 #include "opt_irqstats.h" 43 44 #include "assym.h" 45 #include <machine/asm.h> 46 #include <machine/cpu.h> 47 #include <machine/frame.h> 48 #include <arm/iomd/iomdreg.h> 49 50 .text 51 .align 0 52 /* 53 * ffs table used for servicing irq's quickly must be here otherwise adr can't 54 * reach it 55 * The algorithm for ffs was devised by D. Seal and posted to 56 * comp.sys.arm on 16 Feb 1994. 57 */ 58 .type Lirq_ffs_table, _ASM_TYPE_OBJECT; 59 Lirq_ffs_table: 60 /* same as ffs table but all nums are -1 from that */ 61 /* 0 1 2 3 4 5 6 7 */ 62 .byte 0, 0, 1, 12, 2, 6, 0, 13 /* 0- 7 */ 63 .byte 3, 0, 7, 0, 0, 0, 0, 14 /* 8-15 */ 64 .byte 10, 4, 0, 0, 8, 0, 0, 25 /* 16-23 */ 65 .byte 0, 0, 0, 0, 0, 21, 27, 15 /* 24-31 */ 66 .byte 31, 11, 5, 0, 0, 0, 0, 0 /* 32-39 */ 67 .byte 9, 0, 0, 24, 0, 0, 20, 26 /* 40-47 */ 68 .byte 30, 0, 0, 0, 0, 23, 0, 19 /* 48-55 */ 69 .byte 29, 0, 22, 18, 28, 17, 16, 0 /* 56-63 */ 70 71 /* 72 * 73 * irq_entry 74 * 75 * Main entry point for the IRQ vector 76 * 77 * This function reads the irq request bits in the IOMD registers 78 * IRQRQA, IRQRQB and DMARQ 79 * It then calls an installed handler for each bit that is set. 80 * The function stray_irqhandler is called if a handler is not defined 81 * for a particular interrupt. 82 * If a interrupt handler is found then it is called with r0 containing 83 * the argument defined in the handler structure. If the field ih_arg 84 * is zero then a pointer to the IRQ frame on the stack is passed instead. 85 */ 86 87 Ldisabled_mask: 88 .word _C_LABEL(disabled_mask) 89 90 Lcurrent_spl_level: 91 .word _C_LABEL(current_spl_level) 92 93 Lcurrent_intr_depth: 94 .word _C_LABEL(current_intr_depth) 95 96 Lspl_masks: 97 .word _C_LABEL(spl_masks) 98 99 AST_ALIGNMENT_FAULT_LOCALS 100 101 /* 102 * Register usage 103 * 104 * r5 - Address of ffs table 105 * r6 - Address of current handler 106 * r7 - Pointer to handler pointer list 107 * r8 - Current IRQ requests. 108 * r10 - Base address of IOMD 109 * r11 - IRQ requests still to service. 110 */ 111 112 Liomd_base: 113 .word _C_LABEL(iomd_base) 114 115 Larm7500_ioc_found: 116 .word _C_LABEL(arm7500_ioc_found) 117 118 ASENTRY_NP(irq_entry) 119 sub lr, lr, #0x00000004 /* Adjust the lr */ 120 121 PUSHFRAMEINSVC /* Push an interrupt frame */ 122 ENABLE_ALIGNMENT_FAULTS 123 124 /* Load r8 with the IOMD interrupt requests */ 125 126 ldr r10, Liomd_base 127 ldr r10, [r10] /* Point to the IOMD */ 128 ldrb r8, [r10, #(IOMD_IRQRQA << 2)] /* Get IRQ request A */ 129 ldrb r9, [r10, #(IOMD_IRQRQB << 2)] /* Get IRQ request B */ 130 orr r8, r8, r9, lsl #8 131 132 ldr r9, Larm7500_ioc_found 133 ldr r9, [r9] /* get the flag */ 134 cmp r9, #0 135 beq skip_extended_IRQs_reading 136 137 /* ARM 7500 only */ 138 ldrb r9, [r10, #(IOMD_IRQRQC << 2)] /* Get IRQ request C */ 139 orr r8, r8, r9, lsl #16 140 ldrb r9, [r10, #(IOMD_IRQRQD << 2)] /* Get IRQ request D */ 141 orr r8, r8, r9, lsl #24 142 ldrb r9, [r10, #(IOMD_DMARQ << 2)] /* Get DMA Request */ 143 tst r9, #0x10 144 orrne r8, r8, r9, lsl #27 145 b irq_entry_continue 146 147 skip_extended_IRQs_reading: 148 /* non ARM7500 machines */ 149 ldrb r9, [r10, #(IOMD_DMARQ << 2)] /* Get DMA Request */ 150 orr r8, r8, r9, lsl #16 151 irq_entry_continue: 152 153 and r0, r8, #0x7d /* Clear IOMD IRQA bits */ 154 strb r0, [r10, #(IOMD_IRQRQA << 2)] 155 156 /* 157 * Note that we have entered the IRQ handler. 158 * We are in SVC mode so we cannot use the processor mode 159 * to determine if we are in an IRQ. Instead we will count the 160 * each time the interrupt handler is nested. 161 */ 162 163 ldr r0, Lcurrent_intr_depth 164 ldr r1, [r0] 165 add r1, r1, #1 166 str r1, [r0] 167 168 /* Block the current requested interrupts */ 169 ldr r1, Ldisabled_mask 170 ldr r0, [r1] 171 stmfd sp!, {r0} 172 orr r0, r0, r8 173 174 /* 175 * Need to block all interrupts at the IPL or lower for 176 * all asserted interrupts. 177 * This basically emulates hardware interrupt priority levels. 178 * Means we need to go through the interrupt mask and for 179 * every asserted interrupt we need to mask out all other 180 * interrupts at the same or lower IPL. 181 * If only we could wait until the main loop but we need to sort 182 * this out first so interrupts can be re-enabled. 183 * 184 * This would benefit from a special ffs type routine 185 */ 186 187 mov r9, #(_SPL_LEVELS - 1) 188 ldr r7, Lspl_masks 189 190 Lfind_highest_ipl: 191 ldr r2, [r7, r9, lsl #2] 192 tst r8, r2 193 subeq r9, r9, #1 194 beq Lfind_highest_ipl 195 196 /* r9 = SPL level of highest priority interrupt */ 197 add r9, r9, #1 198 ldr r2, [r7, r9, lsl #2] 199 mvn r2, r2 200 orr r0, r0, r2 201 202 str r0, [r1] 203 204 ldr r0, Lcurrent_spl_level 205 ldr r1, [r0] 206 str r9, [r0] 207 stmfd sp!, {r1} 208 209 /* Update the IOMD irq masks */ 210 bl _C_LABEL(irq_setmasks) 211 212 mrs r0, cpsr_all /* Enable IRQ's */ 213 bic r0, r0, #I32_bit 214 msr cpsr_all, r0 215 216 ldr r7, Lirqhandlers 217 218 /* 219 * take a copy of the IRQ request so that we can strip bits out of it 220 * note that we only use 24 bits with iomd2 chips 221 */ 222 ldr r4, Larm7500_ioc_found 223 ldr r4, [r4] /* get the flag */ 224 cmp r4, #0 225 movne r11, r8 /* ARM7500 -> copy all bits */ 226 biceq r11, r8, #0xff000000 /* !ARM7500 -> only use 24 bit */ 227 228 /* ffs routine to find first irq to service */ 229 /* standard trick to isolate bottom bit in a0 or 0 if a0 = 0 on entry */ 230 rsb r4, r11, #0 231 ands r10, r11, r4 232 233 /* 234 * now r10 has at most 1 set bit, call this X 235 * if X = 0, branch to exit code 236 */ 237 beq exitirq 238 adr r5, Lirq_ffs_table 239 irqloop: 240 /* 241 * at this point: 242 * r5 = address of ffs table 243 * r7 = address of irq handlers table 244 * r8 = irq request 245 * r10 = bit of irq to be serviced 246 * r11 = bitmask of IRQ's to service 247 */ 248 249 /* find the set bit */ 250 orr r9, r10, r10, lsl #4 /* X * 0x11 */ 251 orr r9, r9, r9, lsl #6 /* X * 0x451 */ 252 rsb r9, r9, r9, lsl #16 /* X * 0x0450fbaf */ 253 /* fetch the bit number */ 254 ldrb r9, [r5, r9, lsr #26 ] 255 256 /* 257 * r9 = irq to service 258 */ 259 260 /* apologies for the dogs dinner of code here, but it's in an attempt 261 * to minimise stalling on SA's, hence lots of things happen here: 262 * - getting address of handler, if it doesn't exist we call 263 * stray_irqhandler this is assumed to be rare so we don't 264 * care about performance for it 265 * - statinfo is updated 266 * - unsetting of the irq bit in r11 267 * - irq stats (if enabled) also get put in the mix 268 */ 269 ldr r4, Lcnt /* Stat info A */ 270 ldr r6, [r7, r9, lsl #2] /* Get address of first handler structure */ 271 272 ldr r1, [r4, #(V_INTR)] /* Stat info B */ 273 274 teq r6, #0x00000000 /* Do we have a handler */ 275 moveq r0, r8 /* IRQ requests as arg 0 */ 276 adreq lr, nextirq /* return Address */ 277 beq _C_LABEL(stray_irqhandler) /* call special handler */ 278 279 #ifdef IRQSTATS 280 ldr r2, Lintrcnt 281 ldr r3, [r6, #(IH_NUM)] 282 #endif 283 /* stat info C */ 284 add r1, r1, #0x00000001 285 str r1, [r4, #(V_INTR)] 286 287 #ifdef IRQSTATS 288 ldr r3, [r2, r3, lsl #2]! 289 #endif 290 bic r11, r11, r10 /* clear the IRQ bit */ 291 292 #ifdef IRQSTATS 293 add r3, r3, #0x00000001 294 str r3, [r2] 295 #endif /* IRQSTATS */ 296 297 irqchainloop: 298 ldr r0, [r6, #(IH_ARG)] /* Get argument pointer */ 299 teq r0, #0x00000000 /* If arg is zero pass stack frame */ 300 addeq r0, sp, #8 /* ... stack frame [XXX needs care] */ 301 mov lr, pc /* return address */ 302 ldr pc, [r6, #(IH_FUNC)] /* Call handler */ 303 304 ldr r6, [r6, #(IH_NEXT)] /* fetch next handler */ 305 306 teq r0, #0x00000001 /* Was the irq serviced ? */ 307 308 /* if it was it'll just fall through this: */ 309 teqne r6, #0x00000000 310 bne irqchainloop 311 nextirq: 312 /* Check for next irq */ 313 rsb r4, r11, #0 314 ands r10, r11, r4 315 /* check if there are anymore irq's to service */ 316 bne irqloop 317 318 exitirq: 319 ldmfd sp!, {r2, r3} 320 ldr r9, Lcurrent_spl_level 321 ldr r1, Ldisabled_mask 322 str r2, [r9] 323 str r3, [r1] 324 325 bl _C_LABEL(irq_setmasks) 326 327 bl _C_LABEL(dosoftints) /* Handle the soft interrupts */ 328 329 /* Kill IRQ's in preparation for exit */ 330 mrs r0, cpsr_all 331 orr r0, r0, #(I32_bit) 332 msr cpsr_all, r0 333 334 /* Decrement the nest count */ 335 ldr r0, Lcurrent_intr_depth 336 ldr r1, [r0] 337 sub r1, r1, #1 338 str r1, [r0] 339 340 DO_AST_AND_RESTORE_ALIGNMENT_FAULTS 341 PULLFRAMEFROMSVCANDEXIT 342 343 /* NOT REACHED */ 344 b . - 8 345 346 Lspl_mask: 347 .word _C_LABEL(spl_mask) /* irq's allowed at current spl level */ 348 349 Lcurrent_mask: 350 .word _C_LABEL(current_mask) /* irq's that are usable */ 351 352 ENTRY(irq_setmasks) 353 /* Disable interrupts */ 354 mrs r3, cpsr_all 355 orr r1, r3, #(I32_bit) 356 msr cpsr_all, r1 357 358 /* Calculate IOMD interrupt mask */ 359 ldr r1, Lcurrent_mask /* All the enabled interrupts */ 360 ldr r2, Lspl_mask /* Block due to current spl level */ 361 ldr r1, [r1] 362 ldr r2, [r2] 363 and r1, r1, r2 364 ldr r2, Ldisabled_mask /* Block due to active interrupts */ 365 ldr r2, [r2] 366 bic r1, r1, r2 367 368 ldr r0, Liomd_base 369 ldr r0, [r0] /* Point to the IOMD */ 370 strb r1, [r0, #(IOMD_IRQMSKA << 2)] /* Set IRQ mask A */ 371 mov r1, r1, lsr #8 372 strb r1, [r0, #(IOMD_IRQMSKB << 2)] /* Set IRQ mask B */ 373 mov r1, r1, lsr #8 374 375 ldr r2, Larm7500_ioc_found 376 ldr r2, [r2] 377 cmp r2, #0 378 beq skip_setting_extended_DMA_mask 379 380 /* only for ARM7500's */ 381 strb r1, [r0, #(IOMD_IRQMSKC << 2)] 382 mov r1, r1, lsr #8 383 and r2, r1, #0xef 384 strb r2, [r0, #(IOMD_IRQMSKD << 2)] 385 mov r1, r1, lsr #3 386 and r2, r1, #0x10 387 strb r2, [r0, #(IOMD_DMAMSK << 2)] /* Set DMA mask */ 388 b continue_setting_masks 389 390 skip_setting_extended_DMA_mask: 391 /* non ARM7500's */ 392 strb r1, [r0, #(IOMD_DMAMSK << 2)] /* Set DMA mask */ 393 394 continue_setting_masks: 395 396 /* Restore old cpsr and exit */ 397 msr cpsr_all, r3 398 mov pc, lr 399 400 Lcnt: 401 .word _C_LABEL(uvmexp) 402 403 Lintrcnt: 404 .word _C_LABEL(intrcnt) 405 406 407 Lirqhandlers: 408 .word _C_LABEL(irqhandlers) /* Pointer to array of irqhandlers */ 409 410 #ifdef IRQSTATS 411 /* These symbols are used by vmstat */ 412 413 .text 414 .global _C_LABEL(_intrnames) 415 _C_LABEL(_intrnames): 416 .word _C_LABEL(intrnames) 417 418 .data 419 420 .globl _C_LABEL(intrnames), _C_LABEL(eintrnames), _C_LABEL(intrcnt), _C_LABEL(sintrcnt), _C_LABEL(eintrcnt) 421 _C_LABEL(intrnames): 422 .asciz "interrupt 0 " 423 .asciz "interrupt 1 " /* reserved0 */ 424 .asciz "interrupt 2 " 425 .asciz "interrupt 3 " 426 .asciz "interrupt 4 " 427 .asciz "interrupt 5 " 428 .asciz "interrupt 6 " 429 .asciz "interrupt 7 " /* reserved1 */ 430 .asciz "interrupt 8 " /* reserved2 */ 431 .asciz "interrupt 9 " 432 .asciz "interrupt 10 " 433 .asciz "interrupt 11 " 434 .asciz "interrupt 12 " 435 .asciz "interrupt 13 " 436 .asciz "interrupt 14 " 437 .asciz "interrupt 15 " 438 .asciz "dma channel 0" 439 .asciz "dma channel 1" 440 .asciz "dma channel 2" 441 .asciz "dma channel 3" 442 .asciz "interrupt 20 " 443 .asciz "interrupt 21 " 444 .asciz "reserved 3 " 445 .asciz "reserved 4 " 446 .asciz "exp card 0 " 447 .asciz "exp card 1 " 448 .asciz "exp card 2 " 449 .asciz "exp card 3 " 450 .asciz "exp card 4 " 451 .asciz "exp card 5 " 452 .asciz "exp card 6 " 453 .asciz "exp card 7 " 454 455 _C_LABEL(sintrnames): 456 .asciz "softclock " 457 .asciz "softnet " 458 .asciz "softserial " 459 .asciz "softintr 3 " 460 .asciz "softintr 4 " 461 .asciz "softintr 5 " 462 .asciz "softintr 6 " 463 .asciz "softintr 7 " 464 .asciz "softintr 8 " 465 .asciz "softintr 9 " 466 .asciz "softintr 10 " 467 .asciz "softintr 11 " 468 .asciz "softintr 12 " 469 .asciz "softintr 13 " 470 .asciz "softintr 14 " 471 .asciz "softintr 15 " 472 .asciz "softintr 16 " 473 .asciz "softintr 17 " 474 .asciz "softintr 18 " 475 .asciz "softintr 19 " 476 .asciz "softintr 20 " 477 .asciz "softintr 21 " 478 .asciz "softintr 22 " 479 .asciz "softintr 23 " 480 .asciz "softintr 24 " 481 .asciz "softintr 25 " 482 .asciz "softintr 26 " 483 .asciz "softintr 27 " 484 .asciz "softintr 28 " 485 .asciz "softintr 29 " 486 .asciz "softintr 30 " 487 .asciz "softintr 31 " 488 _C_LABEL(eintrnames): 489 490 .bss 491 .align 0 492 _C_LABEL(intrcnt): 493 .space 32*4 /* XXX Should be linked to number of interrupts */ 494 495 _C_LABEL(sintrcnt): 496 .space 32*4 /* XXX Should be linked to number of interrupts */ 497 _C_LABEL(eintrcnt): 498 499 #else /* IRQSTATS */ 500 /* Dummy entries to keep vmstat happy */ 501 502 .text 503 .globl _C_LABEL(intrnames), _C_LABEL(eintrnames), _C_LABEL(intrcnt), _C_LABEL(eintrcnt) 504 _C_LABEL(intrnames): 505 .long 0 506 _C_LABEL(eintrnames): 507 508 _C_LABEL(intrcnt): 509 .long 0 510 _C_LABEL(eintrcnt): 511 #endif /* IRQSTATS */ 512
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