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) 2018 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 #if defined(__amd64) && !defined(__xpv) 475 /* If this fails, then the padding numbers in machcpuvar.h are wrong. */ 476 CTASSERT((offsetof(cpu_t, cpu_m) + offsetof(struct machcpu, mcpu_pad)) < 477 MMU_PAGESIZE); 478 CTASSERT((offsetof(cpu_t, cpu_m) + offsetof(struct machcpu, mcpu_kpti)) >= 479 MMU_PAGESIZE); 480 CTASSERT((offsetof(cpu_t, cpu_m) + offsetof(struct machcpu, mcpu_kpti_dbg)) < 481 2 * MMU_PAGESIZE); 482 CTASSERT((offsetof(cpu_t, cpu_m) + offsetof(struct machcpu, mcpu_pad2)) < 483 2 * MMU_PAGESIZE); 484 CTASSERT(((sizeof (struct kpti_frame)) & 0xF) == 0); 485 CTASSERT(((offsetof(cpu_t, cpu_m) + 486 offsetof(struct machcpu, mcpu_kpti_dbg)) & 0xF) == 0); 487 CTASSERT((offsetof(struct kpti_frame, kf_tr_rsp) & 0xF) == 0); 488 #endif 489 490 #if defined(__xpv) && defined(DEBUG) 491 492 /* 493 * This panic message is intended as an aid to interrupt debugging. 494 * 495 * The associated assertion tests the condition of enabling 496 * events when events are already enabled. The implication 497 * being that whatever code the programmer thought was 498 * protected by having events disabled until the second 499 * enable happened really wasn't protected at all .. 500 */ 501 502 int stistipanic = 1; /* controls the debug panic check */ 503 const char *stistimsg = "stisti"; 504 ulong_t laststi[NCPU]; 505 506 /* 507 * This variable tracks the last place events were disabled on each cpu 508 * it assists in debugging when asserts that interrupts are enabled trip. 509 */ 510 ulong_t lastcli[NCPU]; 511 512 #endif 513 514 void do_interrupt(struct regs *rp, trap_trace_rec_t *ttp); 515 516 void (*do_interrupt_common)(struct regs *, trap_trace_rec_t *) = do_interrupt; 517 uintptr_t (*get_intr_handler)(int, short) = NULL; 518 519 /* 520 * Set cpu's base SPL level to the highest active interrupt level 521 */ 522 void 523 set_base_spl(void) 524 { 525 struct cpu *cpu = CPU; 526 uint16_t active = (uint16_t)cpu->cpu_intr_actv; 527 528 cpu->cpu_base_spl = active == 0 ? 0 : bsrw_insn(active); 529 } 530 531 /* 532 * Do all the work necessary to set up the cpu and thread structures 533 * to dispatch a high-level interrupt. 534 * 535 * Returns 0 if we're -not- already on the high-level interrupt stack, 536 * (and *must* switch to it), non-zero if we are already on that stack. 537 * 538 * Called with interrupts masked. 539 * The 'pil' is already set to the appropriate level for rp->r_trapno. 540 */ 541 static int 542 hilevel_intr_prolog(struct cpu *cpu, uint_t pil, uint_t oldpil, struct regs *rp) 543 { 544 struct machcpu *mcpu = &cpu->cpu_m; 545 uint_t mask; 546 hrtime_t intrtime; 547 hrtime_t now = tsc_read(); 548 549 ASSERT(pil > LOCK_LEVEL); 550 551 if (pil == CBE_HIGH_PIL) { 552 cpu->cpu_profile_pil = oldpil; 553 if (USERMODE(rp->r_cs)) { 554 cpu->cpu_profile_pc = 0; 555 cpu->cpu_profile_upc = rp->r_pc; 556 cpu->cpu_cpcprofile_pc = 0; 557 cpu->cpu_cpcprofile_upc = rp->r_pc; 558 } else { 559 cpu->cpu_profile_pc = rp->r_pc; 560 cpu->cpu_profile_upc = 0; 561 cpu->cpu_cpcprofile_pc = rp->r_pc; 562 cpu->cpu_cpcprofile_upc = 0; 563 } 564 } 565 566 mask = cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK; 567 if (mask != 0) { 568 int nestpil; 569 570 /* 571 * We have interrupted another high-level interrupt. 572 * Load starting timestamp, compute interval, update 573 * cumulative counter. 574 */ 575 nestpil = bsrw_insn((uint16_t)mask); 576 ASSERT(nestpil < pil); 577 intrtime = now - 578 mcpu->pil_high_start[nestpil - (LOCK_LEVEL + 1)]; 579 mcpu->intrstat[nestpil][0] += intrtime; 580 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 581 /* 582 * Another high-level interrupt is active below this one, so 583 * there is no need to check for an interrupt thread. That 584 * will be done by the lowest priority high-level interrupt 585 * active. 586 */ 587 } else { 588 kthread_t *t = cpu->cpu_thread; 589 590 /* 591 * See if we are interrupting a low-level interrupt thread. 592 * If so, account for its time slice only if its time stamp 593 * is non-zero. 594 */ 595 if ((t->t_flag & T_INTR_THREAD) != 0 && t->t_intr_start != 0) { 596 intrtime = now - t->t_intr_start; 597 mcpu->intrstat[t->t_pil][0] += intrtime; 598 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 599 t->t_intr_start = 0; 600 } 601 } 602 603 /* 604 * Store starting timestamp in CPU structure for this PIL. 605 */ 606 mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)] = now; 607 608 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 609 610 if (pil == 15) { 611 /* 612 * To support reentrant level 15 interrupts, we maintain a 613 * recursion count in the top half of cpu_intr_actv. Only 614 * when this count hits zero do we clear the PIL 15 bit from 615 * the lower half of cpu_intr_actv. 616 */ 617 uint16_t *refcntp = (uint16_t *)&cpu->cpu_intr_actv + 1; 618 (*refcntp)++; 619 } 620 621 mask = cpu->cpu_intr_actv; 622 623 cpu->cpu_intr_actv |= (1 << pil); 624 625 return (mask & CPU_INTR_ACTV_HIGH_LEVEL_MASK); 626 } 627 628 /* 629 * Does most of the work of returning from a high level interrupt. 630 * 631 * Returns 0 if there are no more high level interrupts (in which 632 * case we must switch back to the interrupted thread stack) or 633 * non-zero if there are more (in which case we should stay on it). 634 * 635 * Called with interrupts masked 636 */ 637 static int 638 hilevel_intr_epilog(struct cpu *cpu, uint_t pil, uint_t oldpil, uint_t vecnum) 639 { 640 struct machcpu *mcpu = &cpu->cpu_m; 641 uint_t mask; 642 hrtime_t intrtime; 643 hrtime_t now = tsc_read(); 644 645 ASSERT(mcpu->mcpu_pri == pil); 646 647 cpu->cpu_stats.sys.intr[pil - 1]++; 648 649 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 650 651 if (pil == 15) { 652 /* 653 * To support reentrant level 15 interrupts, we maintain a 654 * recursion count in the top half of cpu_intr_actv. Only 655 * when this count hits zero do we clear the PIL 15 bit from 656 * the lower half of cpu_intr_actv. 657 */ 658 uint16_t *refcntp = (uint16_t *)&cpu->cpu_intr_actv + 1; 659 660 ASSERT(*refcntp > 0); 661 662 if (--(*refcntp) == 0) 663 cpu->cpu_intr_actv &= ~(1 << pil); 664 } else { 665 cpu->cpu_intr_actv &= ~(1 << pil); 666 } 667 668 ASSERT(mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)] != 0); 669 670 intrtime = now - mcpu->pil_high_start[pil - (LOCK_LEVEL + 1)]; 671 mcpu->intrstat[pil][0] += intrtime; 672 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 673 674 /* 675 * Check for lower-pil nested high-level interrupt beneath 676 * current one. If so, place a starting timestamp in its 677 * pil_high_start entry. 678 */ 679 mask = cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK; 680 if (mask != 0) { 681 int nestpil; 682 683 /* 684 * find PIL of nested interrupt 685 */ 686 nestpil = bsrw_insn((uint16_t)mask); 687 ASSERT(nestpil < pil); 688 mcpu->pil_high_start[nestpil - (LOCK_LEVEL + 1)] = now; 689 /* 690 * (Another high-level interrupt is active below this one, 691 * so there is no need to check for an interrupt 692 * thread. That will be done by the lowest priority 693 * high-level interrupt active.) 694 */ 695 } else { 696 /* 697 * Check to see if there is a low-level interrupt active. 698 * If so, place a starting timestamp in the thread 699 * structure. 700 */ 701 kthread_t *t = cpu->cpu_thread; 702 703 if (t->t_flag & T_INTR_THREAD) 704 t->t_intr_start = now; 705 } 706 707 mcpu->mcpu_pri = oldpil; 708 (void) (*setlvlx)(oldpil, vecnum); 709 710 return (cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK); 711 } 712 713 /* 714 * Set up the cpu, thread and interrupt thread structures for 715 * executing an interrupt thread. The new stack pointer of the 716 * interrupt thread (which *must* be switched to) is returned. 717 */ 718 static caddr_t 719 intr_thread_prolog(struct cpu *cpu, caddr_t stackptr, uint_t pil) 720 { 721 struct machcpu *mcpu = &cpu->cpu_m; 722 kthread_t *t, *volatile it; 723 hrtime_t now = tsc_read(); 724 725 ASSERT(pil > 0); 726 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 727 cpu->cpu_intr_actv |= (1 << pil); 728 729 /* 730 * Get set to run an interrupt thread. 731 * There should always be an interrupt thread, since we 732 * allocate one for each level on each CPU. 733 * 734 * t_intr_start could be zero due to cpu_intr_swtch_enter. 735 */ 736 t = cpu->cpu_thread; 737 if ((t->t_flag & T_INTR_THREAD) && t->t_intr_start != 0) { 738 hrtime_t intrtime = now - t->t_intr_start; 739 mcpu->intrstat[t->t_pil][0] += intrtime; 740 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 741 t->t_intr_start = 0; 742 } 743 744 ASSERT(SA((uintptr_t)stackptr) == (uintptr_t)stackptr); 745 746 t->t_sp = (uintptr_t)stackptr; /* mark stack in curthread for resume */ 747 748 /* 749 * unlink the interrupt thread off the cpu 750 * 751 * Note that the code in kcpc_overflow_intr -relies- on the 752 * ordering of events here - in particular that t->t_lwp of 753 * the interrupt thread is set to the pinned thread *before* 754 * curthread is changed. 755 */ 756 it = cpu->cpu_intr_thread; 757 cpu->cpu_intr_thread = it->t_link; 758 it->t_intr = t; 759 it->t_lwp = t->t_lwp; 760 761 /* 762 * (threads on the interrupt thread free list could have state 763 * preset to TS_ONPROC, but it helps in debugging if 764 * they're TS_FREE.) 765 */ 766 it->t_state = TS_ONPROC; 767 768 cpu->cpu_thread = it; /* new curthread on this cpu */ 769 it->t_pil = (uchar_t)pil; 770 it->t_pri = intr_pri + (pri_t)pil; 771 it->t_intr_start = now; 772 773 return (it->t_stk); 774 } 775 776 777 #ifdef DEBUG 778 int intr_thread_cnt; 779 #endif 780 781 /* 782 * Called with interrupts disabled 783 */ 784 static void 785 intr_thread_epilog(struct cpu *cpu, uint_t vec, uint_t oldpil) 786 { 787 struct machcpu *mcpu = &cpu->cpu_m; 788 kthread_t *t; 789 kthread_t *it = cpu->cpu_thread; /* curthread */ 790 uint_t pil, basespl; 791 hrtime_t intrtime; 792 hrtime_t now = tsc_read(); 793 794 pil = it->t_pil; 795 cpu->cpu_stats.sys.intr[pil - 1]++; 796 797 ASSERT(it->t_intr_start != 0); 798 intrtime = now - it->t_intr_start; 799 mcpu->intrstat[pil][0] += intrtime; 800 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 801 802 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 803 cpu->cpu_intr_actv &= ~(1 << pil); 804 805 /* 806 * If there is still an interrupted thread underneath this one 807 * then the interrupt was never blocked and the return is 808 * fairly simple. Otherwise it isn't. 809 */ 810 if ((t = it->t_intr) == NULL) { 811 /* 812 * The interrupted thread is no longer pinned underneath 813 * the interrupt thread. This means the interrupt must 814 * have blocked, and the interrupted thread has been 815 * unpinned, and has probably been running around the 816 * system for a while. 817 * 818 * Since there is no longer a thread under this one, put 819 * this interrupt thread back on the CPU's free list and 820 * resume the idle thread which will dispatch the next 821 * thread to run. 822 */ 823 #ifdef DEBUG 824 intr_thread_cnt++; 825 #endif 826 cpu->cpu_stats.sys.intrblk++; 827 /* 828 * Set CPU's base SPL based on active interrupts bitmask 829 */ 830 set_base_spl(); 831 basespl = cpu->cpu_base_spl; 832 mcpu->mcpu_pri = basespl; 833 (*setlvlx)(basespl, vec); 834 (void) splhigh(); 835 sti(); 836 it->t_state = TS_FREE; 837 /* 838 * Return interrupt thread to pool 839 */ 840 it->t_link = cpu->cpu_intr_thread; 841 cpu->cpu_intr_thread = it; 842 swtch(); 843 panic("intr_thread_epilog: swtch returned"); 844 /*NOTREACHED*/ 845 } 846 847 /* 848 * Return interrupt thread to the pool 849 */ 850 it->t_link = cpu->cpu_intr_thread; 851 cpu->cpu_intr_thread = it; 852 it->t_state = TS_FREE; 853 854 basespl = cpu->cpu_base_spl; 855 pil = MAX(oldpil, basespl); 856 mcpu->mcpu_pri = pil; 857 (*setlvlx)(pil, vec); 858 t->t_intr_start = now; 859 cpu->cpu_thread = t; 860 } 861 862 /* 863 * intr_get_time() is a resource for interrupt handlers to determine how 864 * much time has been spent handling the current interrupt. Such a function 865 * is needed because higher level interrupts can arrive during the 866 * processing of an interrupt. intr_get_time() only returns time spent in the 867 * current interrupt handler. 868 * 869 * The caller must be calling from an interrupt handler running at a pil 870 * below or at lock level. Timings are not provided for high-level 871 * interrupts. 872 * 873 * The first time intr_get_time() is called while handling an interrupt, 874 * it returns the time since the interrupt handler was invoked. Subsequent 875 * calls will return the time since the prior call to intr_get_time(). Time 876 * is returned as ticks. Use scalehrtimef() to convert ticks to nsec. 877 * 878 * Theory Of Intrstat[][]: 879 * 880 * uint64_t intrstat[pil][0..1] is an array indexed by pil level, with two 881 * uint64_ts per pil. 882 * 883 * intrstat[pil][0] is a cumulative count of the number of ticks spent 884 * handling all interrupts at the specified pil on this CPU. It is 885 * exported via kstats to the user. 886 * 887 * intrstat[pil][1] is always a count of ticks less than or equal to the 888 * value in [0]. The difference between [1] and [0] is the value returned 889 * by a call to intr_get_time(). At the start of interrupt processing, 890 * [0] and [1] will be equal (or nearly so). As the interrupt consumes 891 * time, [0] will increase, but [1] will remain the same. A call to 892 * intr_get_time() will return the difference, then update [1] to be the 893 * same as [0]. Future calls will return the time since the last call. 894 * Finally, when the interrupt completes, [1] is updated to the same as [0]. 895 * 896 * Implementation: 897 * 898 * intr_get_time() works much like a higher level interrupt arriving. It 899 * "checkpoints" the timing information by incrementing intrstat[pil][0] 900 * to include elapsed running time, and by setting t_intr_start to rdtsc. 901 * It then sets the return value to intrstat[pil][0] - intrstat[pil][1], 902 * and updates intrstat[pil][1] to be the same as the new value of 903 * intrstat[pil][0]. 904 * 905 * In the normal handling of interrupts, after an interrupt handler returns 906 * and the code in intr_thread() updates intrstat[pil][0], it then sets 907 * intrstat[pil][1] to the new value of intrstat[pil][0]. When [0] == [1], 908 * the timings are reset, i.e. intr_get_time() will return [0] - [1] which 909 * is 0. 910 * 911 * Whenever interrupts arrive on a CPU which is handling a lower pil 912 * interrupt, they update the lower pil's [0] to show time spent in the 913 * handler that they've interrupted. This results in a growing discrepancy 914 * between [0] and [1], which is returned the next time intr_get_time() is 915 * called. Time spent in the higher-pil interrupt will not be returned in 916 * the next intr_get_time() call from the original interrupt, because 917 * the higher-pil interrupt's time is accumulated in intrstat[higherpil][]. 918 */ 919 uint64_t 920 intr_get_time(void) 921 { 922 struct cpu *cpu; 923 struct machcpu *mcpu; 924 kthread_t *t; 925 uint64_t time, delta, ret; 926 uint_t pil; 927 928 cli(); 929 cpu = CPU; 930 mcpu = &cpu->cpu_m; 931 t = cpu->cpu_thread; 932 pil = t->t_pil; 933 ASSERT((cpu->cpu_intr_actv & CPU_INTR_ACTV_HIGH_LEVEL_MASK) == 0); 934 ASSERT(t->t_flag & T_INTR_THREAD); 935 ASSERT(pil != 0); 936 ASSERT(t->t_intr_start != 0); 937 938 time = tsc_read(); 939 delta = time - t->t_intr_start; 940 t->t_intr_start = time; 941 942 time = mcpu->intrstat[pil][0] + delta; 943 ret = time - mcpu->intrstat[pil][1]; 944 mcpu->intrstat[pil][0] = time; 945 mcpu->intrstat[pil][1] = time; 946 cpu->cpu_intracct[cpu->cpu_mstate] += delta; 947 948 sti(); 949 return (ret); 950 } 951 952 static caddr_t 953 dosoftint_prolog( 954 struct cpu *cpu, 955 caddr_t stackptr, 956 uint32_t st_pending, 957 uint_t oldpil) 958 { 959 kthread_t *t, *volatile it; 960 struct machcpu *mcpu = &cpu->cpu_m; 961 uint_t pil; 962 hrtime_t now; 963 964 top: 965 ASSERT(st_pending == mcpu->mcpu_softinfo.st_pending); 966 967 pil = bsrw_insn((uint16_t)st_pending); 968 if (pil <= oldpil || pil <= cpu->cpu_base_spl) 969 return (0); 970 971 /* 972 * XX64 Sigh. 973 * 974 * This is a transliteration of the i386 assembler code for 975 * soft interrupts. One question is "why does this need 976 * to be atomic?" One possible race is -other- processors 977 * posting soft interrupts to us in set_pending() i.e. the 978 * CPU might get preempted just after the address computation, 979 * but just before the atomic transaction, so another CPU would 980 * actually set the original CPU's st_pending bit. However, 981 * it looks like it would be simpler to disable preemption there. 982 * Are there other races for which preemption control doesn't work? 983 * 984 * The i386 assembler version -also- checks to see if the bit 985 * being cleared was actually set; if it wasn't, it rechecks 986 * for more. This seems a bit strange, as the only code that 987 * ever clears the bit is -this- code running with interrupts 988 * disabled on -this- CPU. This code would probably be cheaper: 989 * 990 * atomic_and_32((uint32_t *)&mcpu->mcpu_softinfo.st_pending, 991 * ~(1 << pil)); 992 * 993 * and t->t_preempt--/++ around set_pending() even cheaper, 994 * but at this point, correctness is critical, so we slavishly 995 * emulate the i386 port. 996 */ 997 if (atomic_btr32((uint32_t *) 998 &mcpu->mcpu_softinfo.st_pending, pil) == 0) { 999 st_pending = mcpu->mcpu_softinfo.st_pending; 1000 goto top; 1001 } 1002 1003 mcpu->mcpu_pri = pil; 1004 (*setspl)(pil); 1005 1006 now = tsc_read(); 1007 1008 /* 1009 * Get set to run interrupt thread. 1010 * There should always be an interrupt thread since we 1011 * allocate one for each level on the CPU. 1012 */ 1013 it = cpu->cpu_intr_thread; 1014 cpu->cpu_intr_thread = it->t_link; 1015 1016 /* t_intr_start could be zero due to cpu_intr_swtch_enter. */ 1017 t = cpu->cpu_thread; 1018 if ((t->t_flag & T_INTR_THREAD) && t->t_intr_start != 0) { 1019 hrtime_t intrtime = now - t->t_intr_start; 1020 mcpu->intrstat[pil][0] += intrtime; 1021 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 1022 t->t_intr_start = 0; 1023 } 1024 1025 /* 1026 * Note that the code in kcpc_overflow_intr -relies- on the 1027 * ordering of events here - in particular that t->t_lwp of 1028 * the interrupt thread is set to the pinned thread *before* 1029 * curthread is changed. 1030 */ 1031 it->t_lwp = t->t_lwp; 1032 it->t_state = TS_ONPROC; 1033 1034 /* 1035 * Push interrupted thread onto list from new thread. 1036 * Set the new thread as the current one. 1037 * Set interrupted thread's T_SP because if it is the idle thread, 1038 * resume() may use that stack between threads. 1039 */ 1040 1041 ASSERT(SA((uintptr_t)stackptr) == (uintptr_t)stackptr); 1042 t->t_sp = (uintptr_t)stackptr; 1043 1044 it->t_intr = t; 1045 cpu->cpu_thread = it; 1046 1047 /* 1048 * Set bit for this pil in CPU's interrupt active bitmask. 1049 */ 1050 ASSERT((cpu->cpu_intr_actv & (1 << pil)) == 0); 1051 cpu->cpu_intr_actv |= (1 << pil); 1052 1053 /* 1054 * Initialize thread priority level from intr_pri 1055 */ 1056 it->t_pil = (uchar_t)pil; 1057 it->t_pri = (pri_t)pil + intr_pri; 1058 it->t_intr_start = now; 1059 1060 return (it->t_stk); 1061 } 1062 1063 static void 1064 dosoftint_epilog(struct cpu *cpu, uint_t oldpil) 1065 { 1066 struct machcpu *mcpu = &cpu->cpu_m; 1067 kthread_t *t, *it; 1068 uint_t pil, basespl; 1069 hrtime_t intrtime; 1070 hrtime_t now = tsc_read(); 1071 1072 it = cpu->cpu_thread; 1073 pil = it->t_pil; 1074 1075 cpu->cpu_stats.sys.intr[pil - 1]++; 1076 1077 ASSERT(cpu->cpu_intr_actv & (1 << pil)); 1078 cpu->cpu_intr_actv &= ~(1 << pil); 1079 intrtime = now - it->t_intr_start; 1080 mcpu->intrstat[pil][0] += intrtime; 1081 cpu->cpu_intracct[cpu->cpu_mstate] += intrtime; 1082 1083 /* 1084 * If there is still an interrupted thread underneath this one 1085 * then the interrupt was never blocked and the return is 1086 * fairly simple. Otherwise it isn't. 1087 */ 1088 if ((t = it->t_intr) == NULL) { 1089 /* 1090 * Put thread back on the interrupt thread list. 1091 * This was an interrupt thread, so set CPU's base SPL. 1092 */ 1093 set_base_spl(); 1094 it->t_state = TS_FREE; 1095 it->t_link = cpu->cpu_intr_thread; 1096 cpu->cpu_intr_thread = it; 1097 (void) splhigh(); 1098 sti(); 1099 swtch(); 1100 /*NOTREACHED*/ 1101 panic("dosoftint_epilog: swtch returned"); 1102 } 1103 it->t_link = cpu->cpu_intr_thread; 1104 cpu->cpu_intr_thread = it; 1105 it->t_state = TS_FREE; 1106 cpu->cpu_thread = t; 1107 if (t->t_flag & T_INTR_THREAD) 1108 t->t_intr_start = now; 1109 basespl = cpu->cpu_base_spl; 1110 pil = MAX(oldpil, basespl); 1111 mcpu->mcpu_pri = pil; 1112 (*setspl)(pil); 1113 } 1114 1115 1116 /* 1117 * Make the interrupted thread 'to' be runnable. 1118 * 1119 * Since t->t_sp has already been saved, t->t_pc is all 1120 * that needs to be set in this function. 1121 * 1122 * Returns the interrupt level of the interrupt thread. 1123 */ 1124 int 1125 intr_passivate( 1126 kthread_t *it, /* interrupt thread */ 1127 kthread_t *t) /* interrupted thread */ 1128 { 1129 extern void _sys_rtt(); 1130 1131 ASSERT(it->t_flag & T_INTR_THREAD); 1132 ASSERT(SA(t->t_sp) == t->t_sp); 1133 1134 t->t_pc = (uintptr_t)_sys_rtt; 1135 return (it->t_pil); 1136 } 1137 1138 /* 1139 * Create interrupt kstats for this CPU. 1140 */ 1141 void 1142 cpu_create_intrstat(cpu_t *cp) 1143 { 1144 int i; 1145 kstat_t *intr_ksp; 1146 kstat_named_t *knp; 1147 char name[KSTAT_STRLEN]; 1148 zoneid_t zoneid; 1149 1150 ASSERT(MUTEX_HELD(&cpu_lock)); 1151 1152 if (pool_pset_enabled()) 1153 zoneid = GLOBAL_ZONEID; 1154 else 1155 zoneid = ALL_ZONES; 1156 1157 intr_ksp = kstat_create_zone("cpu", cp->cpu_id, "intrstat", "misc", 1158 KSTAT_TYPE_NAMED, PIL_MAX * 2, 0, zoneid); 1159 1160 /* 1161 * Initialize each PIL's named kstat 1162 */ 1163 if (intr_ksp != NULL) { 1164 intr_ksp->ks_update = cpu_kstat_intrstat_update; 1165 knp = (kstat_named_t *)intr_ksp->ks_data; 1166 intr_ksp->ks_private = cp; 1167 for (i = 0; i < PIL_MAX; i++) { 1168 (void) snprintf(name, KSTAT_STRLEN, "level-%d-time", 1169 i + 1); 1170 kstat_named_init(&knp[i * 2], name, KSTAT_DATA_UINT64); 1171 (void) snprintf(name, KSTAT_STRLEN, "level-%d-count", 1172 i + 1); 1173 kstat_named_init(&knp[(i * 2) + 1], name, 1174 KSTAT_DATA_UINT64); 1175 } 1176 kstat_install(intr_ksp); 1177 } 1178 } 1179 1180 /* 1181 * Delete interrupt kstats for this CPU. 1182 */ 1183 void 1184 cpu_delete_intrstat(cpu_t *cp) 1185 { 1186 kstat_delete_byname_zone("cpu", cp->cpu_id, "intrstat", ALL_ZONES); 1187 } 1188 1189 /* 1190 * Convert interrupt statistics from CPU ticks to nanoseconds and 1191 * update kstat. 1192 */ 1193 int 1194 cpu_kstat_intrstat_update(kstat_t *ksp, int rw) 1195 { 1196 kstat_named_t *knp = ksp->ks_data; 1197 cpu_t *cpup = (cpu_t *)ksp->ks_private; 1198 int i; 1199 hrtime_t hrt; 1200 1201 if (rw == KSTAT_WRITE) 1202 return (EACCES); 1203 1204 for (i = 0; i < PIL_MAX; i++) { 1205 hrt = (hrtime_t)cpup->cpu_m.intrstat[i + 1][0]; 1206 scalehrtimef(&hrt); 1207 knp[i * 2].value.ui64 = (uint64_t)hrt; 1208 knp[(i * 2) + 1].value.ui64 = cpup->cpu_stats.sys.intr[i]; 1209 } 1210 1211 return (0); 1212 } 1213 1214 /* 1215 * An interrupt thread is ending a time slice, so compute the interval it 1216 * ran for and update the statistic for its PIL. 1217 */ 1218 void 1219 cpu_intr_swtch_enter(kthread_id_t t) 1220 { 1221 uint64_t interval; 1222 uint64_t start; 1223 cpu_t *cpu; 1224 1225 ASSERT((t->t_flag & T_INTR_THREAD) != 0); 1226 ASSERT(t->t_pil > 0 && t->t_pil <= LOCK_LEVEL); 1227 1228 /* 1229 * We could be here with a zero timestamp. This could happen if: 1230 * an interrupt thread which no longer has a pinned thread underneath 1231 * it (i.e. it blocked at some point in its past) has finished running 1232 * its handler. intr_thread() updated the interrupt statistic for its 1233 * PIL and zeroed its timestamp. Since there was no pinned thread to 1234 * return to, swtch() gets called and we end up here. 1235 * 1236 * Note that we use atomic ops below (atomic_cas_64 and 1237 * atomic_add_64), which we don't use in the functions above, 1238 * because we're not called with interrupts blocked, but the 1239 * epilog/prolog functions are. 1240 */ 1241 if (t->t_intr_start) { 1242 do { 1243 start = t->t_intr_start; 1244 interval = tsc_read() - start; 1245 } while (atomic_cas_64(&t->t_intr_start, start, 0) != start); 1246 cpu = CPU; 1247 cpu->cpu_m.intrstat[t->t_pil][0] += interval; 1248 1249 atomic_add_64((uint64_t *)&cpu->cpu_intracct[cpu->cpu_mstate], 1250 interval); 1251 } else 1252 ASSERT(t->t_intr == NULL); 1253 } 1254 1255 /* 1256 * An interrupt thread is returning from swtch(). Place a starting timestamp 1257 * in its thread structure. 1258 */ 1259 void 1260 cpu_intr_swtch_exit(kthread_id_t t) 1261 { 1262 uint64_t ts; 1263 1264 ASSERT((t->t_flag & T_INTR_THREAD) != 0); 1265 ASSERT(t->t_pil > 0 && t->t_pil <= LOCK_LEVEL); 1266 1267 do { 1268 ts = t->t_intr_start; 1269 } while (atomic_cas_64(&t->t_intr_start, ts, tsc_read()) != ts); 1270 } 1271 1272 /* 1273 * Dispatch a hilevel interrupt (one above LOCK_LEVEL) 1274 */ 1275 /*ARGSUSED*/ 1276 static void 1277 dispatch_hilevel(uint_t vector, uint_t arg2) 1278 { 1279 sti(); 1280 av_dispatch_autovect(vector); 1281 cli(); 1282 } 1283 1284 /* 1285 * Dispatch a soft interrupt 1286 */ 1287 /*ARGSUSED*/ 1288 static void 1289 dispatch_softint(uint_t oldpil, uint_t arg2) 1290 { 1291 struct cpu *cpu = CPU; 1292 1293 sti(); 1294 av_dispatch_softvect((int)cpu->cpu_thread->t_pil); 1295 cli(); 1296 1297 /* 1298 * Must run softint_epilog() on the interrupt thread stack, since 1299 * there may not be a return from it if the interrupt thread blocked. 1300 */ 1301 dosoftint_epilog(cpu, oldpil); 1302 } 1303 1304 /* 1305 * Dispatch a normal interrupt 1306 */ 1307 static void 1308 dispatch_hardint(uint_t vector, uint_t oldipl) 1309 { 1310 struct cpu *cpu = CPU; 1311 1312 sti(); 1313 av_dispatch_autovect(vector); 1314 cli(); 1315 1316 /* 1317 * Must run intr_thread_epilog() on the interrupt thread stack, since 1318 * there may not be a return from it if the interrupt thread blocked. 1319 */ 1320 intr_thread_epilog(cpu, vector, oldipl); 1321 } 1322 1323 /* 1324 * Deliver any softints the current interrupt priority allows. 1325 * Called with interrupts disabled. 1326 */ 1327 void 1328 dosoftint(struct regs *regs) 1329 { 1330 struct cpu *cpu = CPU; 1331 int oldipl; 1332 caddr_t newsp; 1333 1334 while (cpu->cpu_softinfo.st_pending) { 1335 oldipl = cpu->cpu_pri; 1336 newsp = dosoftint_prolog(cpu, (caddr_t)regs, 1337 cpu->cpu_softinfo.st_pending, oldipl); 1338 /* 1339 * If returned stack pointer is NULL, priority is too high 1340 * to run any of the pending softints now. 1341 * Break out and they will be run later. 1342 */ 1343 if (newsp == NULL) 1344 break; 1345 switch_sp_and_call(newsp, dispatch_softint, oldipl, 0); 1346 } 1347 } 1348 1349 /* 1350 * Interrupt service routine, called with interrupts disabled. 1351 */ 1352 /*ARGSUSED*/ 1353 void 1354 do_interrupt(struct regs *rp, trap_trace_rec_t *ttp) 1355 { 1356 struct cpu *cpu = CPU; 1357 int newipl, oldipl = cpu->cpu_pri; 1358 uint_t vector; 1359 caddr_t newsp; 1360 1361 #ifdef TRAPTRACE 1362 ttp->ttr_marker = TT_INTERRUPT; 1363 ttp->ttr_ipl = 0xff; 1364 ttp->ttr_pri = oldipl; 1365 ttp->ttr_spl = cpu->cpu_base_spl; 1366 ttp->ttr_vector = 0xff; 1367 #endif /* TRAPTRACE */ 1368 1369 cpu_idle_exit(CPU_IDLE_CB_FLAG_INTR); 1370 1371 ++*(uint16_t *)&cpu->cpu_m.mcpu_istamp; 1372 1373 /* 1374 * If it's a softint go do it now. 1375 */ 1376 if (rp->r_trapno == T_SOFTINT) { 1377 dosoftint(rp); 1378 ASSERT(!interrupts_enabled()); 1379 return; 1380 } 1381 1382 /* 1383 * Raise the interrupt priority. 1384 */ 1385 newipl = (*setlvl)(oldipl, (int *)&rp->r_trapno); 1386 #ifdef TRAPTRACE 1387 ttp->ttr_ipl = newipl; 1388 #endif /* TRAPTRACE */ 1389 1390 /* 1391 * Bail if it is a spurious interrupt 1392 */ 1393 if (newipl == -1) 1394 return; 1395 cpu->cpu_pri = newipl; 1396 vector = rp->r_trapno; 1397 #ifdef TRAPTRACE 1398 ttp->ttr_vector = vector; 1399 #endif /* TRAPTRACE */ 1400 if (newipl > LOCK_LEVEL) { 1401 /* 1402 * High priority interrupts run on this cpu's interrupt stack. 1403 */ 1404 if (hilevel_intr_prolog(cpu, newipl, oldipl, rp) == 0) { 1405 newsp = cpu->cpu_intr_stack; 1406 switch_sp_and_call(newsp, dispatch_hilevel, vector, 0); 1407 } else { /* already on the interrupt stack */ 1408 dispatch_hilevel(vector, 0); 1409 } 1410 (void) hilevel_intr_epilog(cpu, newipl, oldipl, vector); 1411 } else { 1412 /* 1413 * Run this interrupt in a separate thread. 1414 */ 1415 newsp = intr_thread_prolog(cpu, (caddr_t)rp, newipl); 1416 switch_sp_and_call(newsp, dispatch_hardint, vector, oldipl); 1417 } 1418 1419 #if !defined(__xpv) 1420 /* 1421 * Deliver any pending soft interrupts. 1422 */ 1423 if (cpu->cpu_softinfo.st_pending) 1424 dosoftint(rp); 1425 #endif /* !__xpv */ 1426 } 1427 1428 1429 /* 1430 * Common tasks always done by _sys_rtt, called with interrupts disabled. 1431 * Returns 1 if returning to userland, 0 if returning to system mode. 1432 */ 1433 int 1434 sys_rtt_common(struct regs *rp) 1435 { 1436 kthread_t *tp; 1437 extern void mutex_exit_critical_start(); 1438 extern long mutex_exit_critical_size; 1439 extern void mutex_owner_running_critical_start(); 1440 extern long mutex_owner_running_critical_size; 1441 1442 loop: 1443 1444 /* 1445 * Check if returning to user 1446 */ 1447 tp = CPU->cpu_thread; 1448 if (USERMODE(rp->r_cs)) { 1449 pcb_t *pcb; 1450 1451 /* 1452 * Check if AST pending. 1453 */ 1454 if (tp->t_astflag) { 1455 /* 1456 * Let trap() handle the AST 1457 */ 1458 sti(); 1459 rp->r_trapno = T_AST; 1460 trap(rp, (caddr_t)0, CPU->cpu_id); 1461 cli(); 1462 goto loop; 1463 } 1464 1465 pcb = &tp->t_lwp->lwp_pcb; 1466 1467 /* 1468 * Check to see if we need to initialize the FPU for this 1469 * thread. This should be an uncommon occurrence, but may happen 1470 * in the case where the system creates an lwp through an 1471 * abnormal path such as the agent lwp. Make sure that we still 1472 * happen to have the FPU in a good state. 1473 */ 1474 if ((pcb->pcb_fpu.fpu_flags & FPU_EN) == 0) { 1475 kpreempt_disable(); 1476 fp_seed(); 1477 kpreempt_enable(); 1478 PCB_SET_UPDATE_FPU(pcb); 1479 } 1480 1481 /* 1482 * We are done if segment registers do not need updating. 1483 */ 1484 if (!PCB_NEED_UPDATE(pcb)) 1485 return (1); 1486 1487 if (PCB_NEED_UPDATE_SEGS(pcb) && update_sregs(rp, tp->t_lwp)) { 1488 /* 1489 * 1 or more of the selectors is bad. 1490 * Deliver a SIGSEGV. 1491 */ 1492 proc_t *p = ttoproc(tp); 1493 1494 sti(); 1495 mutex_enter(&p->p_lock); 1496 tp->t_lwp->lwp_cursig = SIGSEGV; 1497 mutex_exit(&p->p_lock); 1498 psig(); 1499 tp->t_sig_check = 1; 1500 cli(); 1501 } 1502 PCB_CLEAR_UPDATE_SEGS(pcb); 1503 1504 if (PCB_NEED_UPDATE_FPU(pcb)) { 1505 fprestore_ctxt(&pcb->pcb_fpu); 1506 } 1507 PCB_CLEAR_UPDATE_FPU(pcb); 1508 1509 ASSERT0(PCB_NEED_UPDATE(pcb)); 1510 1511 return (1); 1512 } 1513 1514 #if !defined(__xpv) 1515 /* 1516 * Assert that we're not trying to return into the syscall return 1517 * trampolines. Things will go baaaaad if we try to do that. 1518 * 1519 * Note that none of these run with interrupts on, so this should 1520 * never happen (even in the sysexit case the STI doesn't take effect 1521 * until after sysexit finishes). 1522 */ 1523 extern void tr_sysc_ret_start(); 1524 extern void tr_sysc_ret_end(); 1525 ASSERT(!(rp->r_pc >= (uintptr_t)tr_sysc_ret_start && 1526 rp->r_pc <= (uintptr_t)tr_sysc_ret_end)); 1527 #endif 1528 1529 /* 1530 * Here if we are returning to supervisor mode. 1531 * Check for a kernel preemption request. 1532 */ 1533 if (CPU->cpu_kprunrun && (rp->r_ps & PS_IE)) { 1534 1535 /* 1536 * Do nothing if already in kpreempt 1537 */ 1538 if (!tp->t_preempt_lk) { 1539 tp->t_preempt_lk = 1; 1540 sti(); 1541 kpreempt(1); /* asynchronous kpreempt call */ 1542 cli(); 1543 tp->t_preempt_lk = 0; 1544 } 1545 } 1546 1547 /* 1548 * If we interrupted the mutex_exit() critical region we must 1549 * reset the PC back to the beginning to prevent missed wakeups 1550 * See the comments in mutex_exit() for details. 1551 */ 1552 if ((uintptr_t)rp->r_pc - (uintptr_t)mutex_exit_critical_start < 1553 mutex_exit_critical_size) { 1554 rp->r_pc = (greg_t)mutex_exit_critical_start; 1555 } 1556 1557 /* 1558 * If we interrupted the mutex_owner_running() critical region we 1559 * must reset the PC back to the beginning to prevent dereferencing 1560 * of a freed thread pointer. See the comments in mutex_owner_running 1561 * for details. 1562 */ 1563 if ((uintptr_t)rp->r_pc - 1564 (uintptr_t)mutex_owner_running_critical_start < 1565 mutex_owner_running_critical_size) { 1566 rp->r_pc = (greg_t)mutex_owner_running_critical_start; 1567 } 1568 1569 return (0); 1570 } 1571 1572 void 1573 send_dirint(int cpuid, int int_level) 1574 { 1575 (*send_dirintf)(cpuid, int_level); 1576 } 1577 1578 #define IS_FAKE_SOFTINT(flag, newpri) \ 1579 (((flag) & PS_IE) && \ 1580 (((*get_pending_spl)() > (newpri)) || \ 1581 bsrw_insn((uint16_t)cpu->cpu_softinfo.st_pending) > (newpri))) 1582 1583 /* 1584 * do_splx routine, takes new ipl to set 1585 * returns the old ipl. 1586 * We are careful not to set priority lower than CPU->cpu_base_pri, 1587 * even though it seems we're raising the priority, it could be set 1588 * higher at any time by an interrupt routine, so we must block interrupts 1589 * and look at CPU->cpu_base_pri 1590 */ 1591 int 1592 do_splx(int newpri) 1593 { 1594 ulong_t flag; 1595 cpu_t *cpu; 1596 int curpri, basepri; 1597 1598 flag = intr_clear(); 1599 cpu = CPU; /* ints are disabled, now safe to cache cpu ptr */ 1600 curpri = cpu->cpu_m.mcpu_pri; 1601 basepri = cpu->cpu_base_spl; 1602 if (newpri < basepri) 1603 newpri = basepri; 1604 cpu->cpu_m.mcpu_pri = newpri; 1605 (*setspl)(newpri); 1606 /* 1607 * If we are going to reenable interrupts see if new priority level 1608 * allows pending softint delivery. 1609 */ 1610 if (IS_FAKE_SOFTINT(flag, newpri)) 1611 fakesoftint(); 1612 ASSERT(!interrupts_enabled()); 1613 intr_restore(flag); 1614 return (curpri); 1615 } 1616 1617 /* 1618 * Common spl raise routine, takes new ipl to set 1619 * returns the old ipl, will not lower ipl. 1620 */ 1621 int 1622 splr(int newpri) 1623 { 1624 ulong_t flag; 1625 cpu_t *cpu; 1626 int curpri, basepri; 1627 1628 flag = intr_clear(); 1629 cpu = CPU; /* ints are disabled, now safe to cache cpu ptr */ 1630 curpri = cpu->cpu_m.mcpu_pri; 1631 /* 1632 * Only do something if new priority is larger 1633 */ 1634 if (newpri > curpri) { 1635 basepri = cpu->cpu_base_spl; 1636 if (newpri < basepri) 1637 newpri = basepri; 1638 cpu->cpu_m.mcpu_pri = newpri; 1639 (*setspl)(newpri); 1640 /* 1641 * See if new priority level allows pending softint delivery 1642 */ 1643 if (IS_FAKE_SOFTINT(flag, newpri)) 1644 fakesoftint(); 1645 } 1646 intr_restore(flag); 1647 return (curpri); 1648 } 1649 1650 int 1651 getpil(void) 1652 { 1653 return (CPU->cpu_m.mcpu_pri); 1654 } 1655 1656 int 1657 spl_xcall(void) 1658 { 1659 return (splr(ipltospl(XCALL_PIL))); 1660 } 1661 1662 int 1663 interrupts_enabled(void) 1664 { 1665 ulong_t flag; 1666 1667 flag = getflags(); 1668 return ((flag & PS_IE) == PS_IE); 1669 } 1670 1671 #ifdef DEBUG 1672 void 1673 assert_ints_enabled(void) 1674 { 1675 ASSERT(!interrupts_unleashed || interrupts_enabled()); 1676 } 1677 #endif /* DEBUG */ 1678