1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2012, Joyent, Inc. All rights reserverd. 25 */ 26 27 /* 28 * To understand the present state of interrupt handling on i86pc, we must 29 * first consider the history of interrupt controllers and our way of handling 30 * interrupts. 31 * 32 * History of Interrupt Controllers on i86pc 33 * ----------------------------------------- 34 * 35 * Intel 8259 and 8259A 36 * 37 * The first interrupt controller that attained widespread use on i86pc was 38 * the Intel 8259(A) Programmable Interrupt Controller that first saw use with 39 * the 8086. It took up to 8 interrupt sources and combined them into one 40 * output wire. Up to 8 8259s could be slaved together providing up to 64 IRQs. 41 * With the switch to the 8259A, level mode interrupts became possible. For a 42 * long time on i86pc the 8259A was the only way to handle interrupts and it 43 * had its own set of quirks. The 8259A and its corresponding interval timer 44 * the 8254 are programmed using outb and inb instructions. 45 * 46 * Intel Advanced Programmable Interrupt Controller (APIC) 47 * 48 * Starting around the time of the introduction of the P6 family 49 * microarchitecture (i686) Intel introduced a new interrupt controller. 50 * Instead of having the series of slaved 8259A devices, Intel opted to outfit 51 * each processor with a Local APIC (lapic) and to outfit the system with at 52 * least one, but potentially more, I/O APICs (ioapic). The lapics and ioapics 53 * initially communicated over a dedicated bus, but this has since been 54 * replaced. Each physical core and even hyperthread currently contains its 55 * own local apic, which is not shared. There are a few exceptions for 56 * hyperthreads, but that does not usually concern us. 57 * 58 * Instead of talking directly to 8259 for status, sending End Of Interrupt 59 * (EOI), etc. a microprocessor now communicates directly to the lapic. This 60 * also allows for each microprocessor to be able to have independent controls. 61 * The programming method is different from the 8259. Consumers map the lapic 62 * registers into uncacheable memory to read and manipulate the state. 63 * 64 * The number of addressable interrupt vectors was increased to 256. However 65 * vectors 0-31 are reserved for the processor exception handling, leaving the 66 * remaining vectors for general use. In addition to hardware generated 67 * interrupts, the lapic provides a way for generating inter-processor 68 * interrupts (IPI) which are the basis for CPU cross calls and CPU pokes. 69 * 70 * AMD ended up implementing the Intel APIC architecture in lieu of their work 71 * with Cyrix. 72 * 73 * Intel x2apic 74 * 75 * The x2apic is an extension to the lapic which started showing up around the 76 * same time as the Sandy Bridge chipsets. It provides a new programming mode 77 * as well as new features. The goal of the x2apic is to solve a few problems 78 * with the previous generation of lapic and the x2apic is backwards compatible 79 * with the previous programming and model. The only downsides to using the 80 * backwards compatibility is that you are not able to take advantage of the new 81 * x2apic features. 82 * 83 * o The APIC ID is increased from an 8-bit value to a 32-bit value. This 84 * increases the maximum number of addressable physical processors beyond 85 * 256. This new ID is assembled in a similar manner as the information that 86 * is obtainable by the extended cpuid topology leaves. 87 * 88 * o A new means of generating IPIs was introduced. 89 * 90 * o Instead of memory mapping the registers, the x2apic only allows for 91 * programming it through a series of wrmsrs. This has important semantic 92 * side effects. Recall that the registers were previously all mapped to 93 * uncachable memory which meant that all operations to the local apic were 94 * serializing instructions. With the switch to using wrmsrs this has been 95 * relaxed and these operations can no longer be assumed to be serializing 96 * instructions. 97 * 98 * Note for the rest of this we are only going to concern ourselves with the 99 * apic and x2apic which practically all of i86pc has been using now for 100 * quite some time. 101 * 102 * Interrupt Priority Levels 103 * ------------------------- 104 * 105 * On i86pc systems there are a total of fifteen interrupt priority levels 106 * (ipls) which range from 1-15. Level 0 is for normal processing and 107 * non-interrupt processing. To manipulate these values the family of spl 108 * functions (which date back to UNIX on the PDP-11) are used. Specifically, 109 * splr() to raise the priority level and splx() to lower it. One should not 110 * generally call setspl() directly. 111 * 112 * Both i86pc and the supported SPARC platforms honor the same conventions for 113 * the meaning behind these IPLs. The most important IPL is the platform's 114 * LOCK_LEVEL (0xa on i86pc). If a thread is above LOCK_LEVEL it _must_ not 115 * sleep on any synchronization object. The only allowed synchronization 116 * primitive is a mutex that has been specifically initialized to be a spin 117 * lock (see mutex_init(9F)). Another important level is DISP_LEVEL (0xb on 118 * i86pc). You must be at DISP_LEVEL if you want to control the dispatcher. 119 * The XC_HI_PIL is the highest level (0xf) and is used during cross-calls. 120 * 121 * Each interrupt that is registered in the system fires at a specific IPL. 122 * Generally most interrupts fire below LOCK_LEVEL. 123 * 124 * PSM Drivers 125 * ----------- 126 * 127 * We currently have three sets of PSM (platform specific module) drivers 128 * available. uppc, pcplusmp, and apix. uppc (uni-processor PC) is the original 129 * driver that interacts with the 8259A and 8254. In general, it is not used 130 * anymore given the prevalence of the apic. 131 * 132 * The system prefers to use the apix driver over the pcplusmp driver. The apix 133 * driver requires HW support for an x2apic. If there is no x2apic HW, apix 134 * will not be used. In general we prefer using the apix driver over the 135 * pcplusmp driver because it gives us much more flexibility with respect to 136 * interrupts. In the apix driver each local apic has its own independent set 137 * of interrupts, whereas the pcplusmp driver only has a single global set of 138 * interrupts. This is why pcplusmp only supports a finite number of interrupts 139 * per IPL -- generally 16, often less. The apix driver supports using either 140 * the x2apic or the local apic programing modes. The programming mode does not 141 * change the number of interrupts available, just the number of processors 142 * that we can address. For the apix driver, the x2apic mode is enabled if the 143 * system supports interrupt re-mapping, otherwise the module manages the 144 * x2apic in local mode. 145 * 146 * When there is no x2apic present, we default back to the pcplusmp PSM driver. 147 * In general, this is not problematic unless you have more than 256 148 * processors in the machine or you do not have enough interrupts available. 149 * 150 * Controlling Interrupt Generation on i86pc 151 * ----------------------------------------- 152 * 153 * There are two different ways to manipulate which interrupts will be 154 * generated on i86pc. Each offers different degrees of control. 155 * 156 * The first is through the flags register (eflags and rflags on i386 and amd64 157 * respectively). The IF bit determines whether or not interrupts are enabled 158 * or disabled. This is manipulated in one of several ways. The most common way 159 * is through the cli and sti instructions. These clear the IF flag and set it, 160 * respectively, for the current processor. The other common way is through the 161 * use of the intr_clear and intr_restore functions. 162 * 163 * Assuming interrupts are not blocked by the IF flag, then the second form is 164 * through the Processor-Priority Register (PPR). The PPR is used to determine 165 * whether or not a pending interrupt should be delivered. If the ipl of the 166 * new interrupt is higher than the current value in the PPR, then the lapic 167 * will either deliver it immediately (if interrupts are not in progress) or it 168 * will deliver it once the current interrupt processing has issued an EOI. The 169 * highest unmasked interrupt will be the one delivered. 170 * 171 * The PPR register is based upon the max of the following two registers in the 172 * lapic, the TPR register (also known as CR8 on amd64) that can be used to 173 * mask interrupt levels, and the current vector. Because the pcplusmp module 174 * always sets TPR appropriately early in the do_interrupt path, we can usually 175 * just think that the PPR is the TPR. The pcplusmp module also issues an EOI 176 * once it has set the TPR, so higher priority interrupts can come in while 177 * we're servicing a lower priority interrupt. 178 * 179 * Handling Interrupts 180 * ------------------- 181 * 182 * Interrupts can be broken down into three categories based on priority and 183 * source: 184 * 185 * o High level interrupts 186 * o Low level hardware interrupts 187 * o Low level software interrupts 188 * 189 * High Level Interrupts 190 * 191 * High level interrupts encompasses both hardware-sourced and software-sourced 192 * interrupts. Examples of high level hardware interrupts include the serial 193 * console. High level software-sourced interrupts are still delivered through 194 * the local apic through IPIs. This is primarily cross calls. 195 * 196 * When a high level interrupt comes in, we will raise the SPL and then pin the 197 * current lwp to the processor. We will use its lwp, but our own interrupt 198 * stack and process the high level interrupt in-situ. These handlers are 199 * designed to be very short in nature and cannot go to sleep, only block on a 200 * spin lock. If the interrupt has a lot of work to do, it must generate a 201 * low-priority software interrupt that will be processed later. 202 * 203 * Low level hardware interrupts 204 * 205 * Low level hardware interrupts start off like their high-level cousins. The 206 * current CPU contains a number of kernel threads (kthread_t) that can be used 207 * to process low level interrupts. These are shared between both low level 208 * hardware and software interrupts. Note that while we run with our 209 * kthread_t, we borrow the pinned threads lwp_t until such a time as we hit a 210 * synchronization object. If we hit one and need to sleep, then the scheduler 211 * will instead create the rest of what we need. 212 * 213 * Low level software interrupts 214 * 215 * Low level software interrupts are handled in a similar way as hardware 216 * interrupts, but the notification vector is different. Each CPU has a bitmask 217 * of pending software interrupts. We can notify a CPU to process software 218 * interrupts through a specific trap vector as well as through several 219 * checks that are performed throughout the code. These checks will look at 220 * processing software interrupts as we lower our spl. 221 * 222 * We attempt to process the highest pending software interrupt that we can 223 * which is greater than our current IPL. If none currently exist, then we move 224 * on. We process a software interrupt in a similar fashion to a hardware 225 * interrupt. 226 * 227 * Traditional Interrupt Flow 228 * -------------------------- 229 * 230 * The following diagram tracks the flow of the traditional uppc and pcplusmp 231 * interrupt handlers. The apix driver has its own version of do_interrupt(). 232 * We come into the interrupt handler with all interrupts masked by the IF 233 * flag. This is because we set up the handler using an interrupt-gate, which 234 * is defined architecturally to have cleared the IF flag for us. 235 * 236 * +--------------+ +----------------+ +-----------+ 237 * | _interrupt() |--->| do_interrupt() |--->| *setlvl() | 238 * +--------------+ +----------------+ +-----------+ 239 * | | | 240 * | | | 241 * low-level| | | softint 242 * HW int | | +---------------------------------------+ 243 * +--------------+ | | | 244 * | intr_thread_ |<-----+ | hi-level int | 245 * | prolog() | | +----------+ | 246 * +--------------+ +--->| hilevel_ | Not on intr stack | 247 * | | intr_ |-----------------+ | 248 * | | prolog() | | | 249 * +------------+ +----------+ | | 250 * | switch_sp_ | | On intr v | 251 * | and_call() | | Stack +------------+ | 252 * +------------+ | | switch_sp_ | | 253 * | v | and_call() | | 254 * v +-----------+ +------------+ | 255 * +-----------+ | dispatch_ | | | 256 * | dispatch_ | +-------------------| hilevel() |<------------+ | 257 * | hardint() | | +-----------+ | 258 * +-----------+ | | 259 * | v | 260 * | +-----+ +----------------------+ +-----+ hi-level | 261 * +---->| sti |->| av_dispatch_autovect |->| cli |---------+ | 262 * +-----+ +----------------------+ +-----+ | | 263 * | | | | 264 * v | | | 265 * +----------+ | | | 266 * | for each | | | | 267 * | handler | | | | 268 * | *intr() | | v | 269 * +--------------+ +----------+ | +----------------+ | 270 * | intr_thread_ | low-level | | hilevel_intr_ | | 271 * | epilog() |<-------------------------------+ | epilog() | | 272 * +--------------+ +----------------+ | 273 * | | | | 274 * | +----------------------v v---------------------+ | 275 * | +------------+ | 276 * | +---------------------->| *setlvlx() | | 277 * | | +------------+ | 278 * | | | | 279 * | | v | 280 * | | +--------+ +------------------+ +-------------+ | 281 * | | | return |<----| softint pending? |----->| dosoftint() |<-----+ 282 * | | +--------+ no +------------------+ yes +-------------+ 283 * | | ^ | | 284 * | | | softint pil too low | | 285 * | | +--------------------------------------+ | 286 * | | v 287 * | | +-----------+ +------------+ +-----------+ 288 * | | | dispatch_ |<-----| switch_sp_ |<---------| *setspl() | 289 * | | | softint() | | and_call() | +-----------+ 290 * | | +-----------+ +------------+ 291 * | | | 292 * | | v 293 * | | +-----+ +----------------------+ +-----+ +------------+ 294 * | | | sti |->| av_dispatch_autovect |->| cli |->| dosoftint_ | 295 * | | +-----+ +----------------------+ +-----+ | epilog() | 296 * | | +------------+ 297 * | | | | 298 * | +----------------------------------------------------+ | 299 * v | 300 * +-----------+ | 301 * | interrupt | | 302 * | thread |<---------------------------------------------------+ 303 * | blocked | 304 * +-----------+ 305 * | 306 * v 307 * +----------------+ +------------+ +-----------+ +-------+ +---------+ 308 * | set_base_spl() |->| *setlvlx() |->| splhigh() |->| sti() |->| swtch() | 309 * +----------------+ +------------+ +-----------+ +-------+ +---------+ 310 * 311 * Calls made on Interrupt Stacks and Epilogue routines 312 * 313 * We use the switch_sp_and_call() assembly routine to switch our sp to the 314 * interrupt stacks and then call the appropriate dispatch function. In the 315 * case of interrupts which may block, softints and hardints, we always ensure 316 * that we are still on the interrupt thread when we call the epilog routine. 317 * This is not just important, it's necessary. If the interrupt thread blocked, 318 * we won't return from our switch_sp_and_call() function and instead we'll go 319 * through and set ourselves up to swtch() directly. 320 * 321 * New Interrupt Flow 322 * ------------------ 323 * 324 * The apix module has its own interrupt path. This is done for various 325 * reasons. The first is that rather than having global interrupt vectors, we 326 * now have per-cpu vectors. 327 * 328 * The other substantial change is that the apix design does not use the TPR to 329 * mask interrupts below the current level. In fact, except for one special 330 * case, it does not use the TPR at all. Instead, it only uses the IF flag 331 * (cli/sti) to either block all interrupts or allow any interrupts to come in. 332 * The design is such that when interrupts are allowed to come in, if we are 333 * currently servicing a higher priority interupt, the new interrupt is treated 334 * as pending and serviced later. Specifically, in the pcplusmp module's 335 * apic_intr_enter() the code masks interrupts at or below the current 336 * IPL using the TPR before sending EOI, whereas the apix module's 337 * apix_intr_enter() simply sends EOI. 338 * 339 * The one special case where the apix code uses the TPR is when it calls 340 * through the apic_reg_ops function pointer apic_write_task_reg in 341 * apix_init_intr() to initially mask all levels and then finally to enable all 342 * levels. 343 * 344 * Recall that we come into the interrupt handler with all interrupts masked 345 * by the IF flag. This is because we set up the handler using an 346 * interrupt-gate which is defined architecturally to have cleared the IF flag 347 * for us. 348 * 349 * +--------------+ +---------------------+ 350 * | _interrupt() |--->| apix_do_interrupt() | 351 * +--------------+ +---------------------+ 352 * | 353 * hard int? +----+--------+ softint? 354 * | | (but no low-level looping) 355 * +-----------+ | 356 * | *setlvl() | | 357 * +---------+ +-----------+ +----------------------------------+ 358 * |apix_add_| check IPL | | 359 * |pending_ |<-------------+------+----------------------+ | 360 * |hardint()| low-level int| hi-level int| | 361 * +---------+ v v | 362 * | check IPL +-----------------+ +---------------+ | 363 * +--+-----+ | apix_intr_ | | apix_hilevel_ | | 364 * | | | thread_prolog() | | intr_prolog() | | 365 * | return +-----------------+ +---------------+ | 366 * | | | On intr | 367 * | +------------+ | stack? +------------+ | 368 * | | switch_sp_ | +---------| switch_sp_ | | 369 * | | and_call() | | | and_call() | | 370 * | +------------+ | +------------+ | 371 * | | | | | 372 * | +----------------+ +----------------+ | 373 * | | apix_dispatch_ | | apix_dispatch_ | | 374 * | | lowlevel() | | hilevel() | | 375 * | +----------------+ +----------------+ | 376 * | | | | 377 * | v v | 378 * | +-------------------------+ | 379 * | |apix_dispatch_by_vector()|----+ | 380 * | +-------------------------+ | | 381 * | !XC_HI_PIL| | | | | 382 * | +---+ +-------+ +---+ | | 383 * | |sti| |*intr()| |cli| | | 384 * | +---+ +-------+ +---+ | hi-level? | 385 * | +---------------------------+----+ | 386 * | v low-level? v | 387 * | +----------------+ +----------------+ | 388 * | | apix_intr_ | | apix_hilevel_ | | 389 * | | thread_epilog()| | intr_epilog() | | 390 * | +----------------+ +----------------+ | 391 * | | | | 392 * | v-----------------+--------------------------------+ | 393 * | +------------+ | 394 * | | *setlvlx() | +----------------------------------------------------+ 395 * | +------------+ | 396 * | | | +--------------------------------+ low 397 * v v v------+ v | level 398 * +------------------+ +------------------+ +-----------+ | pending? 399 * | apix_do_pending_ |----->| apix_do_pending_ |----->| apix_do_ |--+ 400 * | hilevel() | | hardint() | | softint() | | 401 * +------------------+ +------------------+ +-----------+ return 402 * | | | 403 * | while pending | while pending | while pending 404 * | hi-level | low-level | softint 405 * | | | 406 * +---------------+ +-----------------+ +-----------------+ 407 * | apix_hilevel_ | | apix_intr_ | | apix_do_ | 408 * | intr_prolog() | | thread_prolog() | | softint_prolog()| 409 * +---------------+ +-----------------+ +-----------------+ 410 * | On intr | | 411 * | stack? +------------+ +------------+ +------------+ 412 * +--------| switch_sp_ | | switch_sp_ | | switch_sp_ | 413 * | | and_call() | | and_call() | | and_call() | 414 * | +------------+ +------------+ +------------+ 415 * | | | | 416 * +------------------+ +------------------+ +------------------------+ 417 * | apix_dispatch_ | | apix_dispatch_ | | apix_dispatch_softint()| 418 * | pending_hilevel()| | pending_hardint()| +------------------------+ 419 * +------------------+ +------------------+ | | | | 420 * | | | | | | | | 421 * | +----------------+ | +----------------+ | | | | 422 * | | apix_hilevel_ | | | apix_intr_ | | | | | 423 * | | intr_epilog() | | | thread_epilog()| | | | | 424 * | +----------------+ | +----------------+ | | | | 425 * | | | | | | | | 426 * | +------------+ | +----------+ +------+ | | | 427 * | | *setlvlx() | | |*setlvlx()| | | | | 428 * | +------------+ | +----------+ | +----------+ | +---------+ 429 * | | +---+ |av_ | +---+ |apix_do_ | 430 * +---------------------------------+ |sti| |dispatch_ | |cli| |softint_ | 431 * | apix_dispatch_pending_autovect()| +---+ |softvect()| +---+ |epilog() | 432 * +---------------------------------+ +----------+ +---------+ 433 * |!XC_HI_PIL | | | | 434 * +---+ +-------+ +---+ +----------+ +-------+ 435 * |sti| |*intr()| |cli| |apix_post_| |*intr()| 436 * +---+ +-------+ +---+ |hardint() | +-------+ 437 * +----------+ 438 */ 439 440 #include <sys/cpuvar.h> 441 #include <sys/cpu_event.h> 442 #include <sys/regset.h> 443 #include <sys/psw.h> 444 #include <sys/types.h> 445 #include <sys/thread.h> 446 #include <sys/systm.h> 447 #include <sys/segments.h> 448 #include <sys/pcb.h> 449 #include <sys/trap.h> 450 #include <sys/ftrace.h> 451 #include <sys/traptrace.h> 452 #include <sys/clock.h> 453 #include <sys/panic.h> 454 #include <sys/disp.h> 455 #include <vm/seg_kp.h> 456 #include <sys/stack.h> 457 #include <sys/sysmacros.h> 458 #include <sys/cmn_err.h> 459 #include <sys/kstat.h> 460 #include <sys/smp_impldefs.h> 461 #include <sys/pool_pset.h> 462 #include <sys/zone.h> 463 #include <sys/bitmap.h> 464 #include <sys/archsystm.h> 465 #include <sys/machsystm.h> 466 #include <sys/ontrap.h> 467 #include <sys/x86_archext.h> 468 #include <sys/promif.h> 469 #include <vm/hat_i86.h> 470 #if defined(__xpv) 471 #include <sys/hypervisor.h> 472 #endif 473 474 475 #if defined(__xpv) && defined(DEBUG) 476 477 /* 478 * This panic message is intended as an aid to interrupt debugging. 479 * 480 * The associated assertion tests the condition of enabling 481 * events when events are already enabled. The implication 482 * being that whatever code the programmer thought was 483 * protected by having events disabled until the second 484 * enable happened really wasn't protected at all .. 485 */ 486 487 int stistipanic = 1; /* controls the debug panic check */ 488 const char *stistimsg = "stisti"; 489 ulong_t laststi[NCPU]; 490 491 /* 492 * This variable tracks the last place events were disabled on each cpu 493 * it assists in debugging when asserts that interrupts are enabled trip. 494 */ 495 ulong_t lastcli[NCPU]; 496 497 #endif 498 499 void do_interrupt(struct regs *rp, trap_trace_rec_t *ttp); 500 501 void (*do_interrupt_common)(struct regs *, trap_trace_rec_t *) = do_interrupt; 502 uintptr_t (*get_intr_handler)(int, short) = NULL; 503 504 /* 505 * Set cpu's base SPL level to the highest active interrupt level 506 */ 507 void 508 set_base_spl(void) 509 { 510 struct cpu *cpu = CPU; 511 uint16_t active = (uint16_t)cpu->cpu_intr_actv; 512 513 cpu->cpu_base_spl = active == 0 ? 0 : bsrw_insn(active); 514 } 515 516 /* 517 * Do all the work necessary to set up the cpu and thread structures 518 * to dispatch a high-level interrupt. 519 * 520 * Returns 0 if we're -not- already on the high-level interrupt stack, 521 * (and *must* switch to it), non-zero if we are already on that stack. 522 * 523 * Called with interrupts masked. 524 * The 'pil' is already set to the appropriate level for rp->r_trapno. 525 */ 526 static int 527 hilevel_intr_prolog(struct cpu *cpu, uint_t pil, uint_t oldpil, struct regs *rp) 528 { 529 struct machcpu *mcpu = &cpu->cpu_m; 530 uint_t mask; 531 hrtime_t intrtime; 532 hrtime_t now = tsc_read(); 533 534 ASSERT(pil > LOCK_LEVEL); 535 536 if (pil == CBE_HIGH_PIL) { 537 cpu->cpu_profile_pil = oldpil; 538 if (USERMODE(rp->r_cs)) { 539 cpu->cpu_profile_pc = 0; 540 cpu->cpu_profile_upc = rp->r_pc; 541 cpu->cpu_cpcprofile_pc = 0; 542 cpu->cpu_cpcprofile_upc = rp->r_pc; 543 } else { 544 cpu->cpu_profile_pc = rp->r_pc; 545 cpu->cpu_profile_upc = 0; 546 cpu->cpu_cpcprofile_pc = rp->r_pc; 547 cpu->cpu_cpcprofile_upc = 0; 548 } 549 } 550 551 mask = cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK; 552 if (mask != 0) { 553 int nestpil; 554 555 /* 556 * We have interrupted another high-level interrupt. 557 * Load starting timestamp, compute interval, update 558 * cumulative counter. 559 */ 560 nestpil = bsrw_insn((uint16_t)mask); 561 ASSERT(nestpil < pil); 562 intrtime = now - 563 mcpu->pil_high_start[nestpil - (LOCK_LEVEL + 1)]; 564 mcpu->intrstat[nestpil][0] += intrtime; 565 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 566 /* 567 * Another high-level interrupt is active below this one, so 568 * there is no need to check for an interrupt thread. That 569 * will be done by the lowest priority high-level interrupt 570 * active. 571 */ 572 } else { 573 kthread_t *t = cpu->cpu_thread; 574 575 /* 576 * See if we are interrupting a low-level interrupt thread. 577 * If so, account for its time slice only if its time stamp 578 * is non-zero. 579 */ 580 if ((t->t_flag & T_INTR_THREAD) != 0 && t->t_intr_start != 0) { 581 intrtime = now - t->t_intr_start; 582 mcpu->intrstat[t->t_pil][0] += intrtime; 583 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 584 t->t_intr_start = 0; 585 } 586 } 587 588 /* 589 * Store starting timestamp in CPU structure for this PIL. 590 */ 591 mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)] = now; 592 593 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 594 595 if (pil == 15) { 596 /* 597 * To support reentrant level 15 interrupts, we maintain a 598 * recursion count in the top half of cpu_intr_actv. Only 599 * when this count hits zero do we clear the PIL 15 bit from 600 * the lower half of cpu_intr_actv. 601 */ 602 uint16_t *refcntp = (uint16_t *)&cpu->cpu_intr_actv + 1; 603 (*refcntp)++; 604 } 605 606 mask = cpu->cpu_intr_actv; 607 608 cpu->cpu_intr_actv |= (1 << pil); 609 610 return (mask & CPU_INTR_ACTV_HIGH_LEVEL_MASK); 611 } 612 613 /* 614 * Does most of the work of returning from a high level interrupt. 615 * 616 * Returns 0 if there are no more high level interrupts (in which 617 * case we must switch back to the interrupted thread stack) or 618 * non-zero if there are more (in which case we should stay on it). 619 * 620 * Called with interrupts masked 621 */ 622 static int 623 hilevel_intr_epilog(struct cpu *cpu, uint_t pil, uint_t oldpil, uint_t vecnum) 624 { 625 struct machcpu *mcpu = &cpu->cpu_m; 626 uint_t mask; 627 hrtime_t intrtime; 628 hrtime_t now = tsc_read(); 629 630 ASSERT(mcpu->mcpu_pri == pil); 631 632 cpu->cpu_stats.sys.intr[pil - 1]++; 633 634 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 635 636 if (pil == 15) { 637 /* 638 * To support reentrant level 15 interrupts, we maintain a 639 * recursion count in the top half of cpu_intr_actv. Only 640 * when this count hits zero do we clear the PIL 15 bit from 641 * the lower half of cpu_intr_actv. 642 */ 643 uint16_t *refcntp = (uint16_t *)&cpu->cpu_intr_actv + 1; 644 645 ASSERT(*refcntp > 0); 646 647 if (--(*refcntp) == 0) 648 cpu->cpu_intr_actv &= ~(1 << pil); 649 } else { 650 cpu->cpu_intr_actv &= ~(1 << pil); 651 } 652 653 ASSERT(mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)] != 0); 654 655 intrtime = now - mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)]; 656 mcpu->intrstat[pil][0] += intrtime; 657 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 658 659 /* 660 * Check for lower-pil nested high-level interrupt beneath 661 * current one. If so, place a starting timestamp in its 662 * pil_high_start entry. 663 */ 664 mask = cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK; 665 if (mask != 0) { 666 int nestpil; 667 668 /* 669 * find PIL of nested interrupt 670 */ 671 nestpil = bsrw_insn((uint16_t)mask); 672 ASSERT(nestpil < pil); 673 mcpu->pil_high_start[nestpil - (LOCK_LEVEL + 1)] = now; 674 /* 675 * (Another high-level interrupt is active below this one, 676 * so there is no need to check for an interrupt 677 * thread. That will be done by the lowest priority 678 * high-level interrupt active.) 679 */ 680 } else { 681 /* 682 * Check to see if there is a low-level interrupt active. 683 * If so, place a starting timestamp in the thread 684 * structure. 685 */ 686 kthread_t *t = cpu->cpu_thread; 687 688 if (t->t_flag & T_INTR_THREAD) 689 t->t_intr_start = now; 690 } 691 692 mcpu->mcpu_pri = oldpil; 693 (void) (*setlvlx)(oldpil, vecnum); 694 695 return (cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK); 696 } 697 698 /* 699 * Set up the cpu, thread and interrupt thread structures for 700 * executing an interrupt thread. The new stack pointer of the 701 * interrupt thread (which *must* be switched to) is returned. 702 */ 703 static caddr_t 704 intr_thread_prolog(struct cpu *cpu, caddr_t stackptr, uint_t pil) 705 { 706 struct machcpu *mcpu = &cpu->cpu_m; 707 kthread_t *t, *volatile it; 708 hrtime_t now = tsc_read(); 709 710 ASSERT(pil > 0); 711 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 712 cpu->cpu_intr_actv |= (1 << pil); 713 714 /* 715 * Get set to run an interrupt thread. 716 * There should always be an interrupt thread, since we 717 * allocate one for each level on each CPU. 718 * 719 * t_intr_start could be zero due to cpu_intr_swtch_enter. 720 */ 721 t = cpu->cpu_thread; 722 if ((t->t_flag & T_INTR_THREAD) && t->t_intr_start != 0) { 723 hrtime_t intrtime = now - t->t_intr_start; 724 mcpu->intrstat[t->t_pil][0] += intrtime; 725 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 726 t->t_intr_start = 0; 727 } 728 729 ASSERT(SA((uintptr_t)stackptr) == (uintptr_t)stackptr); 730 731 t->t_sp = (uintptr_t)stackptr; /* mark stack in curthread for resume */ 732 733 /* 734 * unlink the interrupt thread off the cpu 735 * 736 * Note that the code in kcpc_overflow_intr -relies- on the 737 * ordering of events here - in particular that t->t_lwp of 738 * the interrupt thread is set to the pinned thread *before* 739 * curthread is changed. 740 */ 741 it = cpu->cpu_intr_thread; 742 cpu->cpu_intr_thread = it->t_link; 743 it->t_intr = t; 744 it->t_lwp = t->t_lwp; 745 746 /* 747 * (threads on the interrupt thread free list could have state 748 * preset to TS_ONPROC, but it helps in debugging if 749 * they're TS_FREE.) 750 */ 751 it->t_state = TS_ONPROC; 752 753 cpu->cpu_thread = it; /* new curthread on this cpu */ 754 it->t_pil = (uchar_t)pil; 755 it->t_pri = intr_pri + (pri_t)pil; 756 it->t_intr_start = now; 757 758 return (it->t_stk); 759 } 760 761 762 #ifdef DEBUG 763 int intr_thread_cnt; 764 #endif 765 766 /* 767 * Called with interrupts disabled 768 */ 769 static void 770 intr_thread_epilog(struct cpu *cpu, uint_t vec, uint_t oldpil) 771 { 772 struct machcpu *mcpu = &cpu->cpu_m; 773 kthread_t *t; 774 kthread_t *it = cpu->cpu_thread; /* curthread */ 775 uint_t pil, basespl; 776 hrtime_t intrtime; 777 hrtime_t now = tsc_read(); 778 779 pil = it->t_pil; 780 cpu->cpu_stats.sys.intr[pil - 1]++; 781 782 ASSERT(it->t_intr_start != 0); 783 intrtime = now - it->t_intr_start; 784 mcpu->intrstat[pil][0] += intrtime; 785 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 786 787 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 788 cpu->cpu_intr_actv &= ~(1 << pil); 789 790 /* 791 * If there is still an interrupted thread underneath this one 792 * then the interrupt was never blocked and the return is 793 * fairly simple. Otherwise it isn't. 794 */ 795 if ((t = it->t_intr) == NULL) { 796 /* 797 * The interrupted thread is no longer pinned underneath 798 * the interrupt thread. This means the interrupt must 799 * have blocked, and the interrupted thread has been 800 * unpinned, and has probably been running around the 801 * system for a while. 802 * 803 * Since there is no longer a thread under this one, put 804 * this interrupt thread back on the CPU's free list and 805 * resume the idle thread which will dispatch the next 806 * thread to run. 807 */ 808 #ifdef DEBUG 809 intr_thread_cnt++; 810 #endif 811 cpu->cpu_stats.sys.intrblk++; 812 /* 813 * Set CPU's base SPL based on active interrupts bitmask 814 */ 815 set_base_spl(); 816 basespl = cpu->cpu_base_spl; 817 mcpu->mcpu_pri = basespl; 818 (*setlvlx)(basespl, vec); 819 (void) splhigh(); 820 sti(); 821 it->t_state = TS_FREE; 822 /* 823 * Return interrupt thread to pool 824 */ 825 it->t_link = cpu->cpu_intr_thread; 826 cpu->cpu_intr_thread = it; 827 swtch(); 828 panic("intr_thread_epilog: swtch returned"); 829 /*NOTREACHED*/ 830 } 831 832 /* 833 * Return interrupt thread to the pool 834 */ 835 it->t_link = cpu->cpu_intr_thread; 836 cpu->cpu_intr_thread = it; 837 it->t_state = TS_FREE; 838 839 basespl = cpu->cpu_base_spl; 840 pil = MAX(oldpil, basespl); 841 mcpu->mcpu_pri = pil; 842 (*setlvlx)(pil, vec); 843 t->t_intr_start = now; 844 cpu->cpu_thread = t; 845 } 846 847 /* 848 * intr_get_time() is a resource for interrupt handlers to determine how 849 * much time has been spent handling the current interrupt. Such a function 850 * is needed because higher level interrupts can arrive during the 851 * processing of an interrupt. intr_get_time() only returns time spent in the 852 * current interrupt handler. 853 * 854 * The caller must be calling from an interrupt handler running at a pil 855 * below or at lock level. Timings are not provided for high-level 856 * interrupts. 857 * 858 * The first time intr_get_time() is called while handling an interrupt, 859 * it returns the time since the interrupt handler was invoked. Subsequent 860 * calls will return the time since the prior call to intr_get_time(). Time 861 * is returned as ticks. Use scalehrtimef() to convert ticks to nsec. 862 * 863 * Theory Of Intrstat[][]: 864 * 865 * uint64_t intrstat[pil][0..1] is an array indexed by pil level, with two 866 * uint64_ts per pil. 867 * 868 * intrstat[pil][0] is a cumulative count of the number of ticks spent 869 * handling all interrupts at the specified pil on this CPU. It is 870 * exported via kstats to the user. 871 * 872 * intrstat[pil][1] is always a count of ticks less than or equal to the 873 * value in [0]. The difference between [1] and [0] is the value returned 874 * by a call to intr_get_time(). At the start of interrupt processing, 875 * [0] and [1] will be equal (or nearly so). As the interrupt consumes 876 * time, [0] will increase, but [1] will remain the same. A call to 877 * intr_get_time() will return the difference, then update [1] to be the 878 * same as [0]. Future calls will return the time since the last call. 879 * Finally, when the interrupt completes, [1] is updated to the same as [0]. 880 * 881 * Implementation: 882 * 883 * intr_get_time() works much like a higher level interrupt arriving. It 884 * "checkpoints" the timing information by incrementing intrstat[pil][0] 885 * to include elapsed running time, and by setting t_intr_start to rdtsc. 886 * It then sets the return value to intrstat[pil][0] - intrstat[pil][1], 887 * and updates intrstat[pil][1] to be the same as the new value of 888 * intrstat[pil][0]. 889 * 890 * In the normal handling of interrupts, after an interrupt handler returns 891 * and the code in intr_thread() updates intrstat[pil][0], it then sets 892 * intrstat[pil][1] to the new value of intrstat[pil][0]. When [0] == [1], 893 * the timings are reset, i.e. intr_get_time() will return [0] - [1] which 894 * is 0. 895 * 896 * Whenever interrupts arrive on a CPU which is handling a lower pil 897 * interrupt, they update the lower pil's [0] to show time spent in the 898 * handler that they've interrupted. This results in a growing discrepancy 899 * between [0] and [1], which is returned the next time intr_get_time() is 900 * called. Time spent in the higher-pil interrupt will not be returned in 901 * the next intr_get_time() call from the original interrupt, because 902 * the higher-pil interrupt's time is accumulated in intrstat[higherpil][]. 903 */ 904 uint64_t 905 intr_get_time(void) 906 { 907 struct cpu *cpu; 908 struct machcpu *mcpu; 909 kthread_t *t; 910 uint64_t time, delta, ret; 911 uint_t pil; 912 913 cli(); 914 cpu = CPU; 915 mcpu = &cpu->cpu_m; 916 t = cpu->cpu_thread; 917 pil = t->t_pil; 918 ASSERT((cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK) == 0); 919 ASSERT(t->t_flag & T_INTR_THREAD); 920 ASSERT(pil != 0); 921 ASSERT(t->t_intr_start != 0); 922 923 time = tsc_read(); 924 delta = time - t->t_intr_start; 925 t->t_intr_start = time; 926 927 time = mcpu->intrstat[pil][0] + delta; 928 ret = time - mcpu->intrstat[pil][1]; 929 mcpu->intrstat[pil][0] = time; 930 mcpu->intrstat[pil][1] = time; 931 cpu->cpu_intracct[cpu->cpu_mstate] += delta; 932 933 sti(); 934 return (ret); 935 } 936 937 static caddr_t 938 dosoftint_prolog( 939 struct cpu *cpu, 940 caddr_t stackptr, 941 uint32_t st_pending, 942 uint_t oldpil) 943 { 944 kthread_t *t, *volatile it; 945 struct machcpu *mcpu = &cpu->cpu_m; 946 uint_t pil; 947 hrtime_t now; 948 949 top: 950 ASSERT(st_pending == mcpu->mcpu_softinfo.st_pending); 951 952 pil = bsrw_insn((uint16_t)st_pending); 953 if (pil <= oldpil || pil <= cpu->cpu_base_spl) 954 return (0); 955 956 /* 957 * XX64 Sigh. 958 * 959 * This is a transliteration of the i386 assembler code for 960 * soft interrupts. One question is "why does this need 961 * to be atomic?" One possible race is -other- processors 962 * posting soft interrupts to us in set_pending() i.e. the 963 * CPU might get preempted just after the address computation, 964 * but just before the atomic transaction, so another CPU would 965 * actually set the original CPU's st_pending bit. However, 966 * it looks like it would be simpler to disable preemption there. 967 * Are there other races for which preemption control doesn't work? 968 * 969 * The i386 assembler version -also- checks to see if the bit 970 * being cleared was actually set; if it wasn't, it rechecks 971 * for more. This seems a bit strange, as the only code that 972 * ever clears the bit is -this- code running with interrupts 973 * disabled on -this- CPU. This code would probably be cheaper: 974 * 975 * atomic_and_32((uint32_t *)&mcpu->mcpu_softinfo.st_pending, 976 * ~(1 << pil)); 977 * 978 * and t->t_preempt--/++ around set_pending() even cheaper, 979 * but at this point, correctness is critical, so we slavishly 980 * emulate the i386 port. 981 */ 982 if (atomic_btr32((uint32_t *) 983 &mcpu->mcpu_softinfo.st_pending, pil) == 0) { 984 st_pending = mcpu->mcpu_softinfo.st_pending; 985 goto top; 986 } 987 988 mcpu->mcpu_pri = pil; 989 (*setspl)(pil); 990 991 now = tsc_read(); 992 993 /* 994 * Get set to run interrupt thread. 995 * There should always be an interrupt thread since we 996 * allocate one for each level on the CPU. 997 */ 998 it = cpu->cpu_intr_thread; 999 cpu->cpu_intr_thread = it->t_link; 1000 1001 /* t_intr_start could be zero due to cpu_intr_swtch_enter. */ 1002 t = cpu->cpu_thread; 1003 if ((t->t_flag & T_INTR_THREAD) && t->t_intr_start != 0) { 1004 hrtime_t intrtime = now - t->t_intr_start; 1005 mcpu->intrstat[pil][0] += intrtime; 1006 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 1007 t->t_intr_start = 0; 1008 } 1009 1010 /* 1011 * Note that the code in kcpc_overflow_intr -relies- on the 1012 * ordering of events here - in particular that t->t_lwp of 1013 * the interrupt thread is set to the pinned thread *before* 1014 * curthread is changed. 1015 */ 1016 it->t_lwp = t->t_lwp; 1017 it->t_state = TS_ONPROC; 1018 1019 /* 1020 * Push interrupted thread onto list from new thread. 1021 * Set the new thread as the current one. 1022 * Set interrupted thread's T_SP because if it is the idle thread, 1023 * resume() may use that stack between threads. 1024 */ 1025 1026 ASSERT(SA((uintptr_t)stackptr) == (uintptr_t)stackptr); 1027 t->t_sp = (uintptr_t)stackptr; 1028 1029 it->t_intr = t; 1030 cpu->cpu_thread = it; 1031 1032 /* 1033 * Set bit for this pil in CPU's interrupt active bitmask. 1034 */ 1035 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 1036 cpu->cpu_intr_actv |= (1 << pil); 1037 1038 /* 1039 * Initialize thread priority level from intr_pri 1040 */ 1041 it->t_pil = (uchar_t)pil; 1042 it->t_pri = (pri_t)pil + intr_pri; 1043 it->t_intr_start = now; 1044 1045 return (it->t_stk); 1046 } 1047 1048 static void 1049 dosoftint_epilog(struct cpu *cpu, uint_t oldpil) 1050 { 1051 struct machcpu *mcpu = &cpu->cpu_m; 1052 kthread_t *t, *it; 1053 uint_t pil, basespl; 1054 hrtime_t intrtime; 1055 hrtime_t now = tsc_read(); 1056 1057 it = cpu->cpu_thread; 1058 pil = it->t_pil; 1059 1060 cpu->cpu_stats.sys.intr[pil - 1]++; 1061 1062 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 1063 cpu->cpu_intr_actv &= ~(1 << pil); 1064 intrtime = now - it->t_intr_start; 1065 mcpu->intrstat[pil][0] += intrtime; 1066 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 1067 1068 /* 1069 * If there is still an interrupted thread underneath this one 1070 * then the interrupt was never blocked and the return is 1071 * fairly simple. Otherwise it isn't. 1072 */ 1073 if ((t = it->t_intr) == NULL) { 1074 /* 1075 * Put thread back on the interrupt thread list. 1076 * This was an interrupt thread, so set CPU's base SPL. 1077 */ 1078 set_base_spl(); 1079 it->t_state = TS_FREE; 1080 it->t_link = cpu->cpu_intr_thread; 1081 cpu->cpu_intr_thread = it; 1082 (void) splhigh(); 1083 sti(); 1084 swtch(); 1085 /*NOTREACHED*/ 1086 panic("dosoftint_epilog: swtch returned"); 1087 } 1088 it->t_link = cpu->cpu_intr_thread; 1089 cpu->cpu_intr_thread = it; 1090 it->t_state = TS_FREE; 1091 cpu->cpu_thread = t; 1092 if (t->t_flag & T_INTR_THREAD) 1093 t->t_intr_start = now; 1094 basespl = cpu->cpu_base_spl; 1095 pil = MAX(oldpil, basespl); 1096 mcpu->mcpu_pri = pil; 1097 (*setspl)(pil); 1098 } 1099 1100 1101 /* 1102 * Make the interrupted thread 'to' be runnable. 1103 * 1104 * Since t->t_sp has already been saved, t->t_pc is all 1105 * that needs to be set in this function. 1106 * 1107 * Returns the interrupt level of the interrupt thread. 1108 */ 1109 int 1110 intr_passivate( 1111 kthread_t *it, /* interrupt thread */ 1112 kthread_t *t) /* interrupted thread */ 1113 { 1114 extern void _sys_rtt(); 1115 1116 ASSERT(it->t_flag & T_INTR_THREAD); 1117 ASSERT(SA(t->t_sp) == t->t_sp); 1118 1119 t->t_pc = (uintptr_t)_sys_rtt; 1120 return (it->t_pil); 1121 } 1122 1123 /* 1124 * Create interrupt kstats for this CPU. 1125 */ 1126 void 1127 cpu_create_intrstat(cpu_t *cp) 1128 { 1129 int i; 1130 kstat_t *intr_ksp; 1131 kstat_named_t *knp; 1132 char name[KSTAT_STRLEN]; 1133 zoneid_t zoneid; 1134 1135 ASSERT(MUTEX_HELD(&cpu_lock)); 1136 1137 if (pool_pset_enabled()) 1138 zoneid = GLOBAL_ZONEID; 1139 else 1140 zoneid = ALL_ZONES; 1141 1142 intr_ksp = kstat_create_zone("cpu", cp->cpu_id, "intrstat", "misc", 1143 KSTAT_TYPE_NAMED, PIL_MAX * 2, NULL, zoneid); 1144 1145 /* 1146 * Initialize each PIL's named kstat 1147 */ 1148 if (intr_ksp != NULL) { 1149 intr_ksp->ks_update = cpu_kstat_intrstat_update; 1150 knp = (kstat_named_t *)intr_ksp->ks_data; 1151 intr_ksp->ks_private = cp; 1152 for (i = 0; i < PIL_MAX; i++) { 1153 (void) snprintf(name, KSTAT_STRLEN, "level-%d-time", 1154 i + 1); 1155 kstat_named_init(&knp[i * 2], name, KSTAT_DATA_UINT64); 1156 (void) snprintf(name, KSTAT_STRLEN, "level-%d-count", 1157 i + 1); 1158 kstat_named_init(&knp[(i * 2) + 1], name, 1159 KSTAT_DATA_UINT64); 1160 } 1161 kstat_install(intr_ksp); 1162 } 1163 } 1164 1165 /* 1166 * Delete interrupt kstats for this CPU. 1167 */ 1168 void 1169 cpu_delete_intrstat(cpu_t *cp) 1170 { 1171 kstat_delete_byname_zone("cpu", cp->cpu_id, "intrstat", ALL_ZONES); 1172 } 1173 1174 /* 1175 * Convert interrupt statistics from CPU ticks to nanoseconds and 1176 * update kstat. 1177 */ 1178 int 1179 cpu_kstat_intrstat_update(kstat_t *ksp, int rw) 1180 { 1181 kstat_named_t *knp = ksp->ks_data; 1182 cpu_t *cpup = (cpu_t *)ksp->ks_private; 1183 int i; 1184 hrtime_t hrt; 1185 1186 if (rw == KSTAT_WRITE) 1187 return (EACCES); 1188 1189 for (i = 0; i < PIL_MAX; i++) { 1190 hrt = (hrtime_t)cpup->cpu_m.intrstat[i + 1][0]; 1191 scalehrtimef(&hrt); 1192 knp[i * 2].value.ui64 = (uint64_t)hrt; 1193 knp[(i * 2) + 1].value.ui64 = cpup->cpu_stats.sys.intr[i]; 1194 } 1195 1196 return (0); 1197 } 1198 1199 /* 1200 * An interrupt thread is ending a time slice, so compute the interval it 1201 * ran for and update the statistic for its PIL. 1202 */ 1203 void 1204 cpu_intr_swtch_enter(kthread_id_t t) 1205 { 1206 uint64_t interval; 1207 uint64_t start; 1208 cpu_t *cpu; 1209 1210 ASSERT((t->t_flag & T_INTR_THREAD) != 0); 1211 ASSERT(t->t_pil > 0 && t->t_pil <= LOCK_LEVEL); 1212 1213 /* 1214 * We could be here with a zero timestamp. This could happen if: 1215 * an interrupt thread which no longer has a pinned thread underneath 1216 * it (i.e. it blocked at some point in its past) has finished running 1217 * its handler. intr_thread() updated the interrupt statistic for its 1218 * PIL and zeroed its timestamp. Since there was no pinned thread to 1219 * return to, swtch() gets called and we end up here. 1220 * 1221 * Note that we use atomic ops below (atomic_cas_64 and 1222 * atomic_add_64), which we don't use in the functions above, 1223 * because we're not called with interrupts blocked, but the 1224 * epilog/prolog functions are. 1225 */ 1226 if (t->t_intr_start) { 1227 do { 1228 start = t->t_intr_start; 1229 interval = tsc_read() - start; 1230 } while (atomic_cas_64(&t->t_intr_start, start, 0) != start); 1231 cpu = CPU; 1232 cpu->cpu_m.intrstat[t->t_pil][0] += interval; 1233 1234 atomic_add_64((uint64_t *)&cpu->cpu_intracct[cpu->cpu_mstate], 1235 interval); 1236 } else 1237 ASSERT(t->t_intr == NULL); 1238 } 1239 1240 /* 1241 * An interrupt thread is returning from swtch(). Place a starting timestamp 1242 * in its thread structure. 1243 */ 1244 void 1245 cpu_intr_swtch_exit(kthread_id_t t) 1246 { 1247 uint64_t ts; 1248 1249 ASSERT((t->t_flag & T_INTR_THREAD) != 0); 1250 ASSERT(t->t_pil > 0 && t->t_pil <= LOCK_LEVEL); 1251 1252 do { 1253 ts = t->t_intr_start; 1254 } while (atomic_cas_64(&t->t_intr_start, ts, tsc_read()) != ts); 1255 } 1256 1257 /* 1258 * Dispatch a hilevel interrupt (one above LOCK_LEVEL) 1259 */ 1260 /*ARGSUSED*/ 1261 static void 1262 dispatch_hilevel(uint_t vector, uint_t arg2) 1263 { 1264 sti(); 1265 av_dispatch_autovect(vector); 1266 cli(); 1267 } 1268 1269 /* 1270 * Dispatch a soft interrupt 1271 */ 1272 /*ARGSUSED*/ 1273 static void 1274 dispatch_softint(uint_t oldpil, uint_t arg2) 1275 { 1276 struct cpu *cpu = CPU; 1277 1278 sti(); 1279 av_dispatch_softvect((int)cpu->cpu_thread->t_pil); 1280 cli(); 1281 1282 /* 1283 * Must run softint_epilog() on the interrupt thread stack, since 1284 * there may not be a return from it if the interrupt thread blocked. 1285 */ 1286 dosoftint_epilog(cpu, oldpil); 1287 } 1288 1289 /* 1290 * Dispatch a normal interrupt 1291 */ 1292 static void 1293 dispatch_hardint(uint_t vector, uint_t oldipl) 1294 { 1295 struct cpu *cpu = CPU; 1296 1297 sti(); 1298 av_dispatch_autovect(vector); 1299 cli(); 1300 1301 /* 1302 * Must run intr_thread_epilog() on the interrupt thread stack, since 1303 * there may not be a return from it if the interrupt thread blocked. 1304 */ 1305 intr_thread_epilog(cpu, vector, oldipl); 1306 } 1307 1308 /* 1309 * Deliver any softints the current interrupt priority allows. 1310 * Called with interrupts disabled. 1311 */ 1312 void 1313 dosoftint(struct regs *regs) 1314 { 1315 struct cpu *cpu = CPU; 1316 int oldipl; 1317 caddr_t newsp; 1318 1319 while (cpu->cpu_softinfo.st_pending) { 1320 oldipl = cpu->cpu_pri; 1321 newsp = dosoftint_prolog(cpu, (caddr_t)regs, 1322 cpu->cpu_softinfo.st_pending, oldipl); 1323 /* 1324 * If returned stack pointer is NULL, priority is too high 1325 * to run any of the pending softints now. 1326 * Break out and they will be run later. 1327 */ 1328 if (newsp == NULL) 1329 break; 1330 switch_sp_and_call(newsp, dispatch_softint, oldipl, 0); 1331 } 1332 } 1333 1334 /* 1335 * Interrupt service routine, called with interrupts disabled. 1336 */ 1337 /*ARGSUSED*/ 1338 void 1339 do_interrupt(struct regs *rp, trap_trace_rec_t *ttp) 1340 { 1341 struct cpu *cpu = CPU; 1342 int newipl, oldipl = cpu->cpu_pri; 1343 uint_t vector; 1344 caddr_t newsp; 1345 1346 #ifdef TRAPTRACE 1347 ttp->ttr_marker = TT_INTERRUPT; 1348 ttp->ttr_ipl = 0xff; 1349 ttp->ttr_pri = oldipl; 1350 ttp->ttr_spl = cpu->cpu_base_spl; 1351 ttp->ttr_vector = 0xff; 1352 #endif /* TRAPTRACE */ 1353 1354 cpu_idle_exit(CPU_IDLE_CB_FLAG_INTR); 1355 1356 ++*(uint16_t *)&cpu->cpu_m.mcpu_istamp; 1357 1358 /* 1359 * If it's a softint go do it now. 1360 */ 1361 if (rp->r_trapno == T_SOFTINT) { 1362 dosoftint(rp); 1363 ASSERT(!interrupts_enabled()); 1364 return; 1365 } 1366 1367 /* 1368 * Raise the interrupt priority. 1369 */ 1370 newipl = (*setlvl)(oldipl, (int *)&rp->r_trapno); 1371 #ifdef TRAPTRACE 1372 ttp->ttr_ipl = newipl; 1373 #endif /* TRAPTRACE */ 1374 1375 /* 1376 * Bail if it is a spurious interrupt 1377 */ 1378 if (newipl == -1) 1379 return; 1380 cpu->cpu_pri = newipl; 1381 vector = rp->r_trapno; 1382 #ifdef TRAPTRACE 1383 ttp->ttr_vector = vector; 1384 #endif /* TRAPTRACE */ 1385 if (newipl > LOCK_LEVEL) { 1386 /* 1387 * High priority interrupts run on this cpu's interrupt stack. 1388 */ 1389 if (hilevel_intr_prolog(cpu, newipl, oldipl, rp) == 0) { 1390 newsp = cpu->cpu_intr_stack; 1391 switch_sp_and_call(newsp, dispatch_hilevel, vector, 0); 1392 } else { /* already on the interrupt stack */ 1393 dispatch_hilevel(vector, 0); 1394 } 1395 (void) hilevel_intr_epilog(cpu, newipl, oldipl, vector); 1396 } else { 1397 /* 1398 * Run this interrupt in a separate thread. 1399 */ 1400 newsp = intr_thread_prolog(cpu, (caddr_t)rp, newipl); 1401 switch_sp_and_call(newsp, dispatch_hardint, vector, oldipl); 1402 } 1403 1404 #if !defined(__xpv) 1405 /* 1406 * Deliver any pending soft interrupts. 1407 */ 1408 if (cpu->cpu_softinfo.st_pending) 1409 dosoftint(rp); 1410 #endif /* !__xpv */ 1411 } 1412 1413 1414 /* 1415 * Common tasks always done by _sys_rtt, called with interrupts disabled. 1416 * Returns 1 if returning to userland, 0 if returning to system mode. 1417 */ 1418 int 1419 sys_rtt_common(struct regs *rp) 1420 { 1421 kthread_t *tp; 1422 extern void mutex_exit_critical_start(); 1423 extern long mutex_exit_critical_size; 1424 extern void mutex_owner_running_critical_start(); 1425 extern long mutex_owner_running_critical_size; 1426 1427 loop: 1428 1429 /* 1430 * Check if returning to user 1431 */ 1432 tp = CPU->cpu_thread; 1433 if (USERMODE(rp->r_cs)) { 1434 /* 1435 * Check if AST pending. 1436 */ 1437 if (tp->t_astflag) { 1438 /* 1439 * Let trap() handle the AST 1440 */ 1441 sti(); 1442 rp->r_trapno = T_AST; 1443 trap(rp, (caddr_t)0, CPU->cpu_id); 1444 cli(); 1445 goto loop; 1446 } 1447 1448 #if defined(__amd64) 1449 /* 1450 * We are done if segment registers do not need updating. 1451 */ 1452 if (tp->t_lwp->lwp_pcb.pcb_rupdate == 0) 1453 return (1); 1454 1455 if (update_sregs(rp, tp->t_lwp)) { 1456 /* 1457 * 1 or more of the selectors is bad. 1458 * Deliver a SIGSEGV. 1459 */ 1460 proc_t *p = ttoproc(tp); 1461 1462 sti(); 1463 mutex_enter(&p->p_lock); 1464 tp->t_lwp->lwp_cursig = SIGSEGV; 1465 mutex_exit(&p->p_lock); 1466 psig(); 1467 tp->t_sig_check = 1; 1468 cli(); 1469 } 1470 tp->t_lwp->lwp_pcb.pcb_rupdate = 0; 1471 1472 #endif /* __amd64 */ 1473 return (1); 1474 } 1475 1476 /* 1477 * Here if we are returning to supervisor mode. 1478 * Check for a kernel preemption request. 1479 */ 1480 if (CPU->cpu_kprunrun && (rp->r_ps & PS_IE)) { 1481 1482 /* 1483 * Do nothing if already in kpreempt 1484 */ 1485 if (!tp->t_preempt_lk) { 1486 tp->t_preempt_lk = 1; 1487 sti(); 1488 kpreempt(1); /* asynchronous kpreempt call */ 1489 cli(); 1490 tp->t_preempt_lk = 0; 1491 } 1492 } 1493 1494 /* 1495 * If we interrupted the mutex_exit() critical region we must 1496 * reset the PC back to the beginning to prevent missed wakeups 1497 * See the comments in mutex_exit() for details. 1498 */ 1499 if ((uintptr_t)rp->r_pc - (uintptr_t)mutex_exit_critical_start < 1500 mutex_exit_critical_size) { 1501 rp->r_pc = (greg_t)mutex_exit_critical_start; 1502 } 1503 1504 /* 1505 * If we interrupted the mutex_owner_running() critical region we 1506 * must reset the PC back to the beginning to prevent dereferencing 1507 * of a freed thread pointer. See the comments in mutex_owner_running 1508 * for details. 1509 */ 1510 if ((uintptr_t)rp->r_pc - 1511 (uintptr_t)mutex_owner_running_critical_start < 1512 mutex_owner_running_critical_size) { 1513 rp->r_pc = (greg_t)mutex_owner_running_critical_start; 1514 } 1515 1516 return (0); 1517 } 1518 1519 void 1520 send_dirint(int cpuid, int int_level) 1521 { 1522 (*send_dirintf)(cpuid, int_level); 1523 } 1524 1525 #define IS_FAKE_SOFTINT(flag, newpri) \ 1526 (((flag) & PS_IE) && \ 1527 (((*get_pending_spl)() > (newpri)) || \ 1528 bsrw_insn((uint16_t)cpu->cpu_softinfo.st_pending) > (newpri))) 1529 1530 /* 1531 * do_splx routine, takes new ipl to set 1532 * returns the old ipl. 1533 * We are careful not to set priority lower than CPU->cpu_base_pri, 1534 * even though it seems we're raising the priority, it could be set 1535 * higher at any time by an interrupt routine, so we must block interrupts 1536 * and look at CPU->cpu_base_pri 1537 */ 1538 int 1539 do_splx(int newpri) 1540 { 1541 ulong_t flag; 1542 cpu_t *cpu; 1543 int curpri, basepri; 1544 1545 flag = intr_clear(); 1546 cpu = CPU; /* ints are disabled, now safe to cache cpu ptr */ 1547 curpri = cpu->cpu_m.mcpu_pri; 1548 basepri = cpu->cpu_base_spl; 1549 if (newpri < basepri) 1550 newpri = basepri; 1551 cpu->cpu_m.mcpu_pri = newpri; 1552 (*setspl)(newpri); 1553 /* 1554 * If we are going to reenable interrupts see if new priority level 1555 * allows pending softint delivery. 1556 */ 1557 if (IS_FAKE_SOFTINT(flag, newpri)) 1558 fakesoftint(); 1559 ASSERT(!interrupts_enabled()); 1560 intr_restore(flag); 1561 return (curpri); 1562 } 1563 1564 /* 1565 * Common spl raise routine, takes new ipl to set 1566 * returns the old ipl, will not lower ipl. 1567 */ 1568 int 1569 splr(int newpri) 1570 { 1571 ulong_t flag; 1572 cpu_t *cpu; 1573 int curpri, basepri; 1574 1575 flag = intr_clear(); 1576 cpu = CPU; /* ints are disabled, now safe to cache cpu ptr */ 1577 curpri = cpu->cpu_m.mcpu_pri; 1578 /* 1579 * Only do something if new priority is larger 1580 */ 1581 if (newpri > curpri) { 1582 basepri = cpu->cpu_base_spl; 1583 if (newpri < basepri) 1584 newpri = basepri; 1585 cpu->cpu_m.mcpu_pri = newpri; 1586 (*setspl)(newpri); 1587 /* 1588 * See if new priority level allows pending softint delivery 1589 */ 1590 if (IS_FAKE_SOFTINT(flag, newpri)) 1591 fakesoftint(); 1592 } 1593 intr_restore(flag); 1594 return (curpri); 1595 } 1596 1597 int 1598 getpil(void) 1599 { 1600 return (CPU->cpu_m.mcpu_pri); 1601 } 1602 1603 int 1604 spl_xcall(void) 1605 { 1606 return (splr(ipltospl(XCALL_PIL))); 1607 } 1608 1609 int 1610 interrupts_enabled(void) 1611 { 1612 ulong_t flag; 1613 1614 flag = getflags(); 1615 return ((flag & PS_IE) == PS_IE); 1616 } 1617 1618 #ifdef DEBUG 1619 void 1620 assert_ints_enabled(void) 1621 { 1622 ASSERT(!interrupts_unleashed || interrupts_enabled()); 1623 } 1624 #endif /* DEBUG */ 1625