2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
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,
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27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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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
36 * Copyright (c) 1989, 1990 William F. Jolitz.
37 * Copyright (c) 1990 The Regents of the University of California.
38 * All rights reserved.
40 * This code is derived from software contributed to Berkeley by
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
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.
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
73 * $FreeBSD: src/sys/i386/isa/ipl.s,v 1.32.2.3 2002/05/16 16:03:56 bde Exp $
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>
87 * Vector interrupt control section
89 * ipending - Pending interrupts (set when a masked interrupt occurs)
90 * spending - Pending software interrupts
95 .globl fastunpend_count
96 fastunpend_count: .long 0
104 * - interrupts are always called with a critical section held
106 * - we release our critical section when scheduling interrupt
107 * or softinterrupt threads in order so they can preempt
108 * (unless we are called manually from a critical section, in
109 * which case there will still be a critical section and
110 * they won't preempt anyway).
112 * - TD_NEST_COUNT prevents splz from nesting too deeply within
113 * itself. It is *not* actually an interrupt nesting count.
114 * PCPU(intr_nesting_level) is an interrupt nesting count.
116 * - We have to be careful in regards to local interrupts
117 * occuring simultaniously with our doreti and splz
120 * - Interrupts must be enabled when calling higher level
121 * functions in order to avoid deadlocking against things
128 * Handle return from interrupts, traps and syscalls. This function
129 * checks the cpl for unmasked pending interrupts (hardware or soft)
130 * and schedules them if appropriate, then irets.
132 * If we are in a critical section we cannot run any pending ints.
134 * The stack contains a trapframe at the start of doreti.
138 .type doreti,@function
140 FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */
141 movq $0,%rax /* irq mask unavailable due to BGL */
142 movq PCPU(curthread),%rbx
143 cli /* interlock with critical section */
144 cmpl $0,PCPU(reqflags) /* short cut if nothing to do */
146 testl $-1,TD_CRITCOUNT(%rbx) /* can't unpend if in critical sec */
148 incl TD_CRITCOUNT(%rbx) /* force all ints to pending */
150 cli /* re-assert cli on loop */
151 movq %rax,%rcx /* irq mask unavailable due to BGL */
154 testl $RQF_IPIQ,PCPU(reqflags)
157 testl $RQF_TIMER,PCPU(reqflags)
160 * check for an unmasked int (3 groups)
163 testq PCPU_E8(ipending,%rdx),%rcx
167 testq PCPU_E8(ipending,%rdx),%rcx
171 testq PCPU_E8(ipending,%rdx),%rcx
174 movl PCPU(spending),%ecx /* check for a pending software int */
178 testl $RQF_AST_MASK,PCPU(reqflags) /* any pending ASTs? */
181 /* ASTs are only applicable when returning to userland */
182 testb $SEL_RPL_MASK,TF_CS(%rsp)
186 * Nothing left to do, finish up. Interrupts are still disabled.
187 * %eax contains the mask of IRQ's that are not available due to
188 * BGL requirements. We can only clear RQF_INTPEND if *ALL* pending
189 * interrupts have been processed.
191 decl TD_CRITCOUNT(%rbx) /* interlocked with cli */
194 andl $~RQF_INTPEND,PCPU(reqflags)
199 * (interrupts are disabled here)
201 * Restore register and iret. iret can fault on %rip (which is
202 * really stupid). If this occurs we re-fault and vector to
203 * doreti_iret_fault().
206 * can be set from user mode, this can result in a kernel mode
207 * exception. The trap code will revector to the *_fault code
208 * which then sets up a T_PROTFLT signal. If the signal is
209 * sent to userland, sendsig() will automatically clean up all
210 * the segment registers to avoid a loop.
213 .globl doreti_syscall_ret
215 POP_FRAME /* registers and %gs (+cli) */
216 /* WARNING: special global doreti_iret is also used by exception.S */
221 * doreti_iret_fault. Alternative return code for the case where
222 * we get a fault in the doreti_exit code above. trap()
223 * (sys/platform/pc64/x86_64/trap.c) catches this specific * case,
224 * sends the process a signal and continues in the corresponding
225 * place in the code below.
227 * Interrupts are likely disabled due to the above interlock
228 * between cli/iretq. We must enable them before calling any
229 * high level function.
232 .globl doreti_iret_fault
236 movq $T_PROTFLT,TF_TRAPNO(%rsp)
237 movq $0,TF_ERR(%rsp) /* XXX should be the error code */
238 movq $0,TF_ADDR(%rsp)
239 FAKE_MCOUNT(TF_RIP(%rsp))
243 * Interrupt pending. NOTE: stack context holds frame structure
244 * for interrupt procedure, do not do random pushes or pops!
248 andq PCPU_E8(ipending,%rdx),%rcx
250 bsfq %rcx, %rcx /* locate the next dispatchable int */
251 btrq %rcx, PCPU_E8(ipending,%rdx)
252 /* is it really still pending? */
256 orq %rdx, %rcx /* form intr number */
258 pushq %rax /* save IRQ mask unavailable for BGL */
259 /* NOTE: is also CPL in frame */
260 call dofastunpend /* unpend intr %rcx */
265 * SOFT interrupt pending
267 * Temporarily back-out our critical section to allow an interrupt
268 * preempt us when we schedule it. Bump intr_nesting_level to
269 * prevent the switch code from recursing via splz too deeply.
274 bsfl %ecx,%ecx /* locate the next pending softint */
275 btrl %ecx,PCPU(spending) /* make sure its still pending */
277 addl $FIRST_SOFTINT,%ecx /* actual intr number */
279 movl %ecx,%edi /* argument to C call */
280 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
281 decl TD_CRITCOUNT(%rbx) /* so we can preempt */
282 call sched_ithd_soft /* YYY must pull in imasks */
283 incl TD_CRITCOUNT(%rbx)
284 decl TD_NEST_COUNT(%rbx)
289 * AST pending. We clear RQF_AST_SIGNAL automatically, the others
290 * are cleared by the trap as they are processed.
292 * Temporarily back-out our critical section because trap() can be
293 * a long-winded call, and we want to be more syscall-like.
295 * YYY theoretically we can call lwkt_switch directly if all we need
296 * to do is a reschedule.
299 andl $~(RQF_AST_SIGNAL|RQF_AST_UPCALL),PCPU(reqflags)
301 movl %eax,%r12d /* save cpl (can't use stack) */
302 movl $T_ASTFLT,TF_TRAPNO(%rsp)
303 movq %rsp,%rdi /* pass frame by ref (%edi = C arg) */
304 decl TD_CRITCOUNT(%rbx)
306 incl TD_CRITCOUNT(%rbx)
307 movl %r12d,%eax /* restore cpl for loop */
312 * IPIQ message pending. We clear RQF_IPIQ automatically.
315 movl %eax,%r12d /* save cpl (can't use stack) */
316 incl PCPU(intr_nesting_level)
317 andl $~RQF_IPIQ,PCPU(reqflags)
319 subq $8,%rsp /* trapframe->intrframe */
320 movq %rsp,%rdi /* pass frame by ref (C arg) */
321 call lwkt_process_ipiq_frame
322 addq $8,%rsp /* intrframe->trapframe */
323 decl PCPU(intr_nesting_level)
324 movl %r12d,%eax /* restore cpl for loop */
329 movl %eax,%r12d /* save cpl (can't use stack) */
330 incl PCPU(intr_nesting_level)
331 andl $~RQF_TIMER,PCPU(reqflags)
333 subq $8,%rsp /* trapframe->intrframe */
334 movq %rsp,%rdi /* pass frame by ref (C arg) */
335 call lapic_timer_process_frame
336 addq $8,%rsp /* intrframe->trapframe */
337 decl PCPU(intr_nesting_level)
338 movl %r12d,%eax /* restore cpl for loop */
342 * SPLZ() a C callable procedure to dispatch any unmasked pending
343 * interrupts regardless of critical section nesting. ASTs
344 * are not dispatched.
346 * Use %eax to track those IRQs that could not be processed
347 * due to BGL requirements.
354 movq PCPU(curthread),%rbx
355 incl TD_CRITCOUNT(%rbx)
360 movq %rax,%rcx /* rcx = ~CPL */
363 testl $RQF_IPIQ,PCPU(reqflags)
366 testl $RQF_TIMER,PCPU(reqflags)
369 * check for an unmasked int (3 groups)
372 testq PCPU_E8(ipending,%rdx),%rcx
376 testq PCPU_E8(ipending,%rdx),%rcx
380 testq PCPU_E8(ipending,%rdx),%rcx
383 movl PCPU(spending),%ecx
387 decl TD_CRITCOUNT(%rbx)
390 * Nothing left to do, finish up. Interrupts are still disabled.
391 * If our mask of IRQs we couldn't process due to BGL requirements
392 * is 0 then there are no pending interrupt sources left and we
393 * can clear RQF_INTPEND.
397 andl $~RQF_INTPEND,PCPU(reqflags)
408 andq PCPU_E8(ipending,%rdx),%rcx
410 bsfq %rcx, %rcx /* locate the next dispatchable int */
411 btrq %rcx, PCPU_E8(ipending,%rdx)
412 /* is it really still pending? */
416 orq %rdx, %rcx /* form intr number */
419 call dofastunpend /* unpend intr %rcx */
424 * SOFT interrupt pending
426 * Temporarily back-out our critical section to allow the interrupt
432 bsfl %ecx,%ecx /* locate the next pending softint */
433 btrl %ecx,PCPU(spending) /* make sure its still pending */
435 addl $FIRST_SOFTINT,%ecx /* actual intr number */
438 movl %ecx,%edi /* C argument */
439 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
440 decl TD_CRITCOUNT(%rbx)
441 call sched_ithd_soft /* YYY must pull in imasks */
442 incl TD_CRITCOUNT(%rbx)
443 decl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
449 andl $~RQF_IPIQ,PCPU(reqflags)
452 call lwkt_process_ipiq
458 andl $~RQF_TIMER,PCPU(reqflags)
461 call lapic_timer_process
466 * dofastunpend(%rcx:intr)
468 * A interrupt previously made pending can now be run,
469 * execute it by pushing a dummy interrupt frame and
470 * calling ithread_fast_handler to execute or schedule it.
472 * ithread_fast_handler() returns 0 if it wants us to unmask
473 * further interrupts.
476 pushfq ; /* phys int frame / flags */ \
477 xorq %rax,%rax ; /* something not SEL_UPL */ \
478 pushq %rax ; /* phys int frame / cs */ \
479 pushq 3*8(%rsp) ; /* original caller eip */ \
480 subq $TF_RIP,%rsp ; /* trap frame */ \
481 movq $0,TF_XFLAGS(%rsp) ; /* extras */ \
482 movq $0,TF_TRAPNO(%rsp) ; /* extras */ \
483 movq $0,TF_ADDR(%rsp) ; /* extras */ \
484 movq $0,TF_FLAGS(%rsp) ; /* extras */ \
485 movq $0,TF_ERR(%rsp) ; /* extras */ \
488 addq $TF_RIP+(3*8),%rsp ; \
491 pushq %rbp /* frame for backtrace */
494 pushq %rcx /* last part of intrframe = intr */
495 incl fastunpend_count
496 movq %rsp,%rdi /* pass frame by reference C arg */
497 call ithread_fast_handler /* returns 0 to unmask */
498 popq %rdi /* intrframe->trapframe */
499 /* + also rdi C arg to next call */
502 movq MachIntrABI + MACHINTR_INTREN, %rax
503 callq *%rax /* MachIntrABI.intren(intr) */