1/* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * --- 35 * 36 * Copyright (c) 1989, 1990 William F. Jolitz. 37 * Copyright (c) 1990 The Regents of the University of California. 38 * All rights reserved. 39 * 40 * This code is derived from software contributed to Berkeley by 41 * William Jolitz. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)ipl.s 72 * 73 * $FreeBSD: src/sys/i386/isa/ipl.s,v 1.32.2.3 2002/05/16 16:03:56 bde Exp $ 74 */ 75 76#include <machine/asmacros.h> 77#include <machine/segments.h> 78#include <machine/ipl.h> 79#include <machine/lock.h> 80#include <machine/psl.h> 81#include <machine/trap.h> 82 83#include "assym.s" 84 85/* 86 * AT/386 87 * Vector interrupt control section 88 * 89 * fpending - Pending interrupts (set when a masked interrupt occurs) 90 * spending - Pending software interrupts 91 */ 92 .data 93 ALIGN_DATA 94 95 .globl fastunpend_count 96fastunpend_count: .long 0 97 98 .text 99 SUPERALIGN_TEXT 100 101 /* 102 * GENERAL NOTES 103 * 104 * - fast interrupts are always called with a critical section 105 * held 106 * 107 * - we release our critical section when scheduling interrupt 108 * or softinterrupt threads in order so they can preempt 109 * (unless we are called manually from a critical section, in 110 * which case there will still be a critical section and 111 * they won't preempt anyway). 112 * 113 * - TD_NEST_COUNT prevents splz from nesting too deeply within 114 * itself. It is *not* actually an interrupt nesting count. 115 * PCPU(intr_nesting_level) is an interrupt nesting count. 116 * 117 * - We have to be careful in regards to local interrupts 118 * occuring simultaniously with our doreti and splz 119 * processing. 120 */ 121 122 /* 123 * DORETI 124 * 125 * Handle return from interrupts, traps and syscalls. This function 126 * checks the cpl for unmasked pending interrupts (fast, normal, or 127 * soft) and schedules them if appropriate, then irets. 128 * 129 * If we are in a critical section we cannot run any pending ints 130 * nor can be play with mp_lock. 131 * 132 * The stack contains a trapframe at the start of doreti. 133 */ 134 SUPERALIGN_TEXT 135 .globl doreti 136 .type doreti,@function 137doreti: 138 FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */ 139 movq $0,%rax /* irq mask unavailable due to BGL */ 140 movq PCPU(curthread),%rbx 141 cli /* interlock with critical section */ 142 cmpl $0,PCPU(reqflags) /* short cut if nothing to do */ 143 je 5f 144 testl $-1,TD_CRITCOUNT(%rbx) /* can't unpend if in critical sec */ 145 jne 5f 146 incl TD_CRITCOUNT(%rbx) /* force all ints to pending */ 147doreti_next: 148 sti /* allow new interrupts */ 149 movl %eax,%ecx /* irq mask unavailable due to BGL */ 150 notl %ecx 151 cli /* disallow YYY remove */ 152#ifdef SMP 153 testl $RQF_IPIQ,PCPU(reqflags) 154 jnz doreti_ipiq 155 testl $RQF_TIMER,PCPU(reqflags) 156 jnz doreti_timer 157#endif 158 testl PCPU(fpending),%ecx /* check for an unmasked fast int */ 159 jnz doreti_fast 160 161 movl PCPU(spending),%ecx /* check for a pending software int */ 162 cmpl $0,%ecx 163 jnz doreti_soft 164 165 testl $RQF_AST_MASK,PCPU(reqflags) /* any pending ASTs? */ 166 jz 2f 167 168 /* ASTs are only applicable when returning to userland */ 169 testb $SEL_RPL_MASK,TF_CS(%rsp) 170 jnz doreti_ast 1712: 172 /* 173 * Nothing left to do, finish up. Interrupts are still disabled. 174 * %eax contains the mask of IRQ's that are not available due to 175 * BGL requirements. We can only clear RQF_INTPEND if *ALL* pending 176 * interrupts have been processed. 177 */ 178 decl TD_CRITCOUNT(%rbx) /* interlocked with cli */ 179 testl %eax,%eax 180 jnz 5f 181 andl $~RQF_INTPEND,PCPU(reqflags) 1825: 183 MEXITCOUNT 184 185 /* 186 * Restore register and iret. iret can fault on %rip (which is 187 * really stupid). If this occurs we re-fault and vector to 188 * doreti_iret_fault(). 189 * 190 * ... 191 * can be set from user mode, this can result in a kernel mode 192 * exception. The trap code will revector to the *_fault code 193 * which then sets up a T_PROTFLT signal. If the signal is 194 * sent to userland, sendsig() will automatically clean up all 195 * the segment registers to avoid a loop. 196 */ 197 .globl doreti_iret 198 .globl doreti_syscall_ret 199doreti_syscall_ret: 200 POP_FRAME /* registers and %gs (+cli) */ 201 /* special global also used by exception.S */ 202doreti_iret: 203 iretq 204 205 /* 206 * doreti_iret_fault. Alternative return code for 207 * the case where we get a fault in the doreti_exit code 208 * above. trap() (sys/platform/pc64/x86_64/trap.c) catches this specific 209 * case, sends the process a signal and continues in the 210 * corresponding place in the code below. 211 */ 212 ALIGN_TEXT 213 .globl doreti_iret_fault 214doreti_iret_fault: 215 PUSH_FRAME_NOSWAP 216 testq $PSL_I,TF_RFLAGS(%rsp) 217 jz 2f 218 sti 2192: 220 movq $T_PROTFLT,TF_TRAPNO(%rsp) 221 movq $0,TF_ERR(%rsp) /* XXX should be the error code */ 222 movq $0,TF_ADDR(%rsp) 223 FAKE_MCOUNT(TF_RIP(%rsp)) 224 jmp calltrap 225 226 /* 227 * FAST interrupt pending. NOTE: stack context holds frame structure 228 * for fast interrupt procedure, do not do random pushes or pops! 229 */ 230 ALIGN_TEXT 231doreti_fast: 232 andl PCPU(fpending),%ecx /* only check fast ints */ 233 bsfl %ecx, %ecx /* locate the next dispatchable int */ 234 btrl %ecx, PCPU(fpending) /* is it really still pending? */ 235 jnc doreti_next 236 pushq %rax /* save IRQ mask unavailable for BGL */ 237 /* NOTE: is also CPL in frame */ 238#if 0 239#ifdef SMP 240 pushq %rcx /* save ecx */ 241 call try_mplock 242 popq %rcx 243 testl %eax,%eax 244 jz 1f 245 /* MP lock successful */ 246#endif 247#endif 248 call dofastunpend /* unpend fast intr %ecx */ 249#if 0 250#ifdef SMP 251 call rel_mplock 252#endif 253#endif 254 popq %rax 255 jmp doreti_next 2561: 257 btsl %ecx, PCPU(fpending) /* oops, couldn't get the MP lock */ 258 popq %rax /* add to temp. cpl mask to ignore */ 259 orl PCPU(fpending),%eax 260 jmp doreti_next 261 262 /* 263 * SOFT interrupt pending 264 * 265 * Temporarily back-out our critical section to allow an interrupt 266 * preempt us when we schedule it. Bump intr_nesting_level to 267 * prevent the switch code from recursing via splz too deeply. 268 */ 269 ALIGN_TEXT 270doreti_soft: 271 bsfl %ecx,%ecx /* locate the next pending softint */ 272 btrl %ecx,PCPU(spending) /* make sure its still pending */ 273 jnc doreti_next 274 addl $FIRST_SOFTINT,%ecx /* actual intr number */ 275 pushq %rax 276 movl %ecx,%edi /* argument to C call */ 277 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */ 278 decl TD_CRITCOUNT(%rbx) /* so we can preempt */ 279 call sched_ithd /* YYY must pull in imasks */ 280 incl TD_CRITCOUNT(%rbx) 281 decl TD_NEST_COUNT(%rbx) 282 popq %rax 283 jmp doreti_next 284 285 /* 286 * AST pending. We clear RQF_AST_SIGNAL automatically, the others 287 * are cleared by the trap as they are processed. 288 * 289 * Temporarily back-out our critical section because trap() can be 290 * a long-winded call, and we want to be more syscall-like. 291 * 292 * YYY theoretically we can call lwkt_switch directly if all we need 293 * to do is a reschedule. 294 */ 295doreti_ast: 296 andl $~(RQF_AST_SIGNAL|RQF_AST_UPCALL),PCPU(reqflags) 297 sti 298 movl %eax,%r12d /* save cpl (can't use stack) */ 299 movl $T_ASTFLT,TF_TRAPNO(%rsp) 300 movq %rsp,%rdi /* pass frame by ref (%edi = C arg) */ 301 decl TD_CRITCOUNT(%rbx) 302 call trap 303 incl TD_CRITCOUNT(%rbx) 304 movl %r12d,%eax /* restore cpl for loop */ 305 jmp doreti_next 306 307#ifdef SMP 308 /* 309 * IPIQ message pending. We clear RQF_IPIQ automatically. 310 */ 311doreti_ipiq: 312 movl %eax,%r12d /* save cpl (can't use stack) */ 313 incl PCPU(intr_nesting_level) 314 andl $~RQF_IPIQ,PCPU(reqflags) 315 subq $8,%rsp /* trapframe->intrframe */ 316 movq %rsp,%rdi /* pass frame by ref (C arg) */ 317 call lwkt_process_ipiq_frame 318 addq $8,%rsp /* intrframe->trapframe */ 319 decl PCPU(intr_nesting_level) 320 movl %r12d,%eax /* restore cpl for loop */ 321 jmp doreti_next 322 323doreti_timer: 324 movl %eax,%r12d /* save cpl (can't use stack) */ 325 incl PCPU(intr_nesting_level) 326 andl $~RQF_TIMER,PCPU(reqflags) 327 subq $8,%rsp /* trapframe->intrframe */ 328 movq %rsp,%rdi /* pass frame by ref (C arg) */ 329 call lapic_timer_process_frame 330 addq $8,%rsp /* intrframe->trapframe */ 331 decl PCPU(intr_nesting_level) 332 movl %r12d,%eax /* restore cpl for loop */ 333 jmp doreti_next 334 335#endif 336 337 /* 338 * SPLZ() a C callable procedure to dispatch any unmasked pending 339 * interrupts regardless of critical section nesting. ASTs 340 * are not dispatched. 341 * 342 * Use %eax to track those IRQs that could not be processed 343 * due to BGL requirements. 344 */ 345 SUPERALIGN_TEXT 346 347ENTRY(splz) 348 pushfq 349 pushq %rbx 350 movq PCPU(curthread),%rbx 351 incl TD_CRITCOUNT(%rbx) 352 movl $0,%eax 353 354splz_next: 355 cli 356 movl %eax,%ecx /* ecx = ~CPL */ 357 notl %ecx 358#ifdef SMP 359 testl $RQF_IPIQ,PCPU(reqflags) 360 jnz splz_ipiq 361 testl $RQF_TIMER,PCPU(reqflags) 362 jnz splz_timer 363#endif 364 testl PCPU(fpending),%ecx /* check for an unmasked fast int */ 365 jnz splz_fast 366 367 movl PCPU(spending),%ecx 368 cmpl $0,%ecx 369 jnz splz_soft 370 371 decl TD_CRITCOUNT(%rbx) 372 373 /* 374 * Nothing left to do, finish up. Interrupts are still disabled. 375 * If our mask of IRQs we couldn't process due to BGL requirements 376 * is 0 then there are no pending interrupt sources left and we 377 * can clear RQF_INTPEND. 378 */ 379 testl %eax,%eax 380 jnz 5f 381 andl $~RQF_INTPEND,PCPU(reqflags) 3825: 383 popq %rbx 384 popfq 385 ret 386 387 /* 388 * FAST interrupt pending 389 */ 390 ALIGN_TEXT 391splz_fast: 392 andl PCPU(fpending),%ecx /* only check fast ints */ 393 bsfl %ecx, %ecx /* locate the next dispatchable int */ 394 btrl %ecx, PCPU(fpending) /* is it really still pending? */ 395 jnc splz_next 396 pushq %rax 397#if 0 398#ifdef SMP 399 movl %ecx,%edi /* argument to try_mplock */ 400 call try_mplock 401 testl %eax,%eax 402 jz 1f 403#endif 404#endif 405 call dofastunpend /* unpend fast intr %ecx */ 406#if 0 407#ifdef SMP 408 call rel_mplock 409#endif 410#endif 411 popq %rax 412 jmp splz_next 4131: 414 btsl %ecx, PCPU(fpending) /* oops, couldn't get the MP lock */ 415 popq %rax 416 orl PCPU(fpending),%eax 417 jmp splz_next 418 419 /* 420 * SOFT interrupt pending 421 * 422 * Temporarily back-out our critical section to allow the interrupt 423 * preempt us. 424 */ 425 ALIGN_TEXT 426splz_soft: 427 bsfl %ecx,%ecx /* locate the next pending softint */ 428 btrl %ecx,PCPU(spending) /* make sure its still pending */ 429 jnc splz_next 430 addl $FIRST_SOFTINT,%ecx /* actual intr number */ 431 sti 432 pushq %rax 433 movl %ecx,%edi /* C argument */ 434 decl TD_CRITCOUNT(%rbx) 435 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */ 436 call sched_ithd /* YYY must pull in imasks */ 437 incl TD_CRITCOUNT(%rbx) 438 decl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */ 439 popq %rax 440 jmp splz_next 441 442#ifdef SMP 443splz_ipiq: 444 andl $~RQF_IPIQ,PCPU(reqflags) 445 pushq %rax 446 call lwkt_process_ipiq 447 popq %rax 448 jmp splz_next 449 450splz_timer: 451 andl $~RQF_TIMER,PCPU(reqflags) 452 pushq %rax 453 call lapic_timer_process 454 popq %rax 455 jmp splz_next 456#endif 457 458 /* 459 * dofastunpend(%ecx:intr) 460 * 461 * A FAST interrupt previously made pending can now be run, 462 * execute it by pushing a dummy interrupt frame and 463 * calling ithread_fast_handler to execute or schedule it. 464 * 465 * ithread_fast_handler() returns 0 if it wants us to unmask 466 * further interrupts. 467 */ 468#define PUSH_DUMMY \ 469 pushfq ; /* phys int frame / flags */ \ 470 movl %cs,%eax ; \ 471 pushq %rax ; /* phys int frame / cs */ \ 472 pushq 3*8(%rsp) ; /* original caller eip */ \ 473 subq $TF_RIP,%rsp ; /* trap frame */ \ 474 movq $0,TF_XFLAGS(%rsp) ; /* extras */ \ 475 movq $0,TF_TRAPNO(%rsp) ; /* extras */ \ 476 movq $0,TF_ADDR(%rsp) ; /* extras */ \ 477 movq $0,TF_FLAGS(%rsp) ; /* extras */ \ 478 movq $0,TF_ERR(%rsp) ; /* extras */ \ 479 480#define POP_DUMMY \ 481 addq $TF_RIP+(3*8),%rsp ; \ 482 483dofastunpend: 484 pushq %rbp /* frame for backtrace */ 485 movq %rsp,%rbp 486 PUSH_DUMMY 487 pushq %rcx /* last part of intrframe = intr */ 488 incl fastunpend_count 489 movq %rsp,%rdi /* pass frame by reference C arg */ 490 call ithread_fast_handler /* returns 0 to unmask */ 491 popq %rdi /* intrframe->trapframe */ 492 /* + also rdi C arg to next call */ 493 cmpl $0,%eax 494 jnz 1f 495 movq MachIntrABI + MACHINTR_INTREN, %rax 496 callq *%rax /* MachIntrABI.intren(intr) */ 4971: 498 POP_DUMMY 499 popq %rbp 500 ret 501 502