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
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.
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;
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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 * fpending - Pending interrupts (set when a masked interrupt occurs)
90 * spending - Pending software interrupts
95 .globl fastunpend_count
96 fastunpend_count: .long 0
104 * - fast interrupts are always called with a critical section
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).
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.
117 * - We have to be careful in regards to local interrupts
118 * occuring simultaniously with our doreti and splz
121 * - Interrupts must be enabled when calling higher level
122 * functions in order to avoid deadlocking against things
129 * Handle return from interrupts, traps and syscalls. This function
130 * checks the cpl for unmasked pending interrupts (fast, normal, or
131 * soft) and schedules them if appropriate, then irets.
133 * If we are in a critical section we cannot run any pending ints.
135 * The stack contains a trapframe at the start of doreti.
139 .type doreti,@function
141 FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */
142 movq $0,%rax /* irq mask unavailable due to BGL */
143 movq PCPU(curthread),%rbx
144 cli /* interlock with critical section */
145 cmpl $0,PCPU(reqflags) /* short cut if nothing to do */
147 testl $-1,TD_CRITCOUNT(%rbx) /* can't unpend if in critical sec */
149 incl TD_CRITCOUNT(%rbx) /* force all ints to pending */
151 cli /* re-assert cli on loop */
152 movl %eax,%ecx /* irq mask unavailable due to BGL */
155 testl $RQF_IPIQ,PCPU(reqflags)
157 testl $RQF_TIMER,PCPU(reqflags)
160 testl PCPU(fpending),%ecx /* check for an unmasked fast int */
163 movl PCPU(spending),%ecx /* check for a pending software int */
167 testl $RQF_AST_MASK,PCPU(reqflags) /* any pending ASTs? */
170 /* ASTs are only applicable when returning to userland */
171 testb $SEL_RPL_MASK,TF_CS(%rsp)
175 * Nothing left to do, finish up. Interrupts are still disabled.
176 * %eax contains the mask of IRQ's that are not available due to
177 * BGL requirements. We can only clear RQF_INTPEND if *ALL* pending
178 * interrupts have been processed.
180 decl TD_CRITCOUNT(%rbx) /* interlocked with cli */
183 andl $~RQF_INTPEND,PCPU(reqflags)
188 * (interrupts are disabled here)
190 * Restore register and iret. iret can fault on %rip (which is
191 * really stupid). If this occurs we re-fault and vector to
192 * doreti_iret_fault().
195 * can be set from user mode, this can result in a kernel mode
196 * exception. The trap code will revector to the *_fault code
197 * which then sets up a T_PROTFLT signal. If the signal is
198 * sent to userland, sendsig() will automatically clean up all
199 * the segment registers to avoid a loop.
202 .globl doreti_syscall_ret
204 POP_FRAME /* registers and %gs (+cli) */
205 /* WARNING: special global doreti_iret is also used by exception.S */
210 * doreti_iret_fault. Alternative return code for the case where
211 * we get a fault in the doreti_exit code above. trap()
212 * (sys/platform/pc64/x86_64/trap.c) catches this specific * case,
213 * sends the process a signal and continues in the corresponding
214 * place in the code below.
216 * Interrupts are likely disabled due to the above interlock
217 * between cli/iretq. We must enable them before calling any
218 * high level function.
221 .globl doreti_iret_fault
225 movq $T_PROTFLT,TF_TRAPNO(%rsp)
226 movq $0,TF_ERR(%rsp) /* XXX should be the error code */
227 movq $0,TF_ADDR(%rsp)
228 FAKE_MCOUNT(TF_RIP(%rsp))
232 * FAST interrupt pending. NOTE: stack context holds frame structure
233 * for fast interrupt procedure, do not do random pushes or pops!
237 andl PCPU(fpending),%ecx /* only check fast ints */
239 bsfl %ecx, %ecx /* locate the next dispatchable int */
240 btrl %ecx, PCPU(fpending) /* is it really still pending? */
242 pushq %rax /* save IRQ mask unavailable for BGL */
243 /* NOTE: is also CPL in frame */
244 call dofastunpend /* unpend fast intr %ecx */
249 * SOFT interrupt pending
251 * Temporarily back-out our critical section to allow an interrupt
252 * preempt us when we schedule it. Bump intr_nesting_level to
253 * prevent the switch code from recursing via splz too deeply.
258 bsfl %ecx,%ecx /* locate the next pending softint */
259 btrl %ecx,PCPU(spending) /* make sure its still pending */
261 addl $FIRST_SOFTINT,%ecx /* actual intr number */
263 movl %ecx,%edi /* argument to C call */
264 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
265 decl TD_CRITCOUNT(%rbx) /* so we can preempt */
266 call sched_ithd /* YYY must pull in imasks */
267 incl TD_CRITCOUNT(%rbx)
268 decl TD_NEST_COUNT(%rbx)
273 * AST pending. We clear RQF_AST_SIGNAL automatically, the others
274 * are cleared by the trap as they are processed.
276 * Temporarily back-out our critical section because trap() can be
277 * a long-winded call, and we want to be more syscall-like.
279 * YYY theoretically we can call lwkt_switch directly if all we need
280 * to do is a reschedule.
283 andl $~(RQF_AST_SIGNAL|RQF_AST_UPCALL),PCPU(reqflags)
285 movl %eax,%r12d /* save cpl (can't use stack) */
286 movl $T_ASTFLT,TF_TRAPNO(%rsp)
287 movq %rsp,%rdi /* pass frame by ref (%edi = C arg) */
288 decl TD_CRITCOUNT(%rbx)
290 incl TD_CRITCOUNT(%rbx)
291 movl %r12d,%eax /* restore cpl for loop */
296 * IPIQ message pending. We clear RQF_IPIQ automatically.
299 movl %eax,%r12d /* save cpl (can't use stack) */
300 incl PCPU(intr_nesting_level)
301 andl $~RQF_IPIQ,PCPU(reqflags)
303 subq $8,%rsp /* trapframe->intrframe */
304 movq %rsp,%rdi /* pass frame by ref (C arg) */
305 call lwkt_process_ipiq_frame
306 addq $8,%rsp /* intrframe->trapframe */
307 decl PCPU(intr_nesting_level)
308 movl %r12d,%eax /* restore cpl for loop */
312 movl %eax,%r12d /* save cpl (can't use stack) */
313 incl PCPU(intr_nesting_level)
314 andl $~RQF_TIMER,PCPU(reqflags)
316 subq $8,%rsp /* trapframe->intrframe */
317 movq %rsp,%rdi /* pass frame by ref (C arg) */
318 call lapic_timer_process_frame
319 addq $8,%rsp /* intrframe->trapframe */
320 decl PCPU(intr_nesting_level)
321 movl %r12d,%eax /* restore cpl for loop */
327 * SPLZ() a C callable procedure to dispatch any unmasked pending
328 * interrupts regardless of critical section nesting. ASTs
329 * are not dispatched.
331 * Use %eax to track those IRQs that could not be processed
332 * due to BGL requirements.
339 movq PCPU(curthread),%rbx
340 incl TD_CRITCOUNT(%rbx)
345 movl %eax,%ecx /* ecx = ~CPL */
348 testl $RQF_IPIQ,PCPU(reqflags)
350 testl $RQF_TIMER,PCPU(reqflags)
353 testl PCPU(fpending),%ecx /* check for an unmasked fast int */
356 movl PCPU(spending),%ecx
360 decl TD_CRITCOUNT(%rbx)
363 * Nothing left to do, finish up. Interrupts are still disabled.
364 * If our mask of IRQs we couldn't process due to BGL requirements
365 * is 0 then there are no pending interrupt sources left and we
366 * can clear RQF_INTPEND.
370 andl $~RQF_INTPEND,PCPU(reqflags)
377 * FAST interrupt pending
381 andl PCPU(fpending),%ecx /* only check fast ints */
383 bsfl %ecx, %ecx /* locate the next dispatchable int */
384 btrl %ecx, PCPU(fpending) /* is it really still pending? */
387 call dofastunpend /* unpend fast intr %ecx */
391 btsl %ecx, PCPU(fpending) /* oops, couldn't get the MP lock */
393 orl PCPU(fpending),%eax
397 * SOFT interrupt pending
399 * Temporarily back-out our critical section to allow the interrupt
405 bsfl %ecx,%ecx /* locate the next pending softint */
406 btrl %ecx,PCPU(spending) /* make sure its still pending */
408 addl $FIRST_SOFTINT,%ecx /* actual intr number */
411 movl %ecx,%edi /* C argument */
412 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
413 decl TD_CRITCOUNT(%rbx)
414 call sched_ithd /* YYY must pull in imasks */
415 incl TD_CRITCOUNT(%rbx)
416 decl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
422 andl $~RQF_IPIQ,PCPU(reqflags)
425 call lwkt_process_ipiq
430 andl $~RQF_TIMER,PCPU(reqflags)
433 call lapic_timer_process
439 * dofastunpend(%ecx:intr)
441 * A FAST interrupt previously made pending can now be run,
442 * execute it by pushing a dummy interrupt frame and
443 * calling ithread_fast_handler to execute or schedule it.
445 * ithread_fast_handler() returns 0 if it wants us to unmask
446 * further interrupts.
449 pushfq ; /* phys int frame / flags */ \
451 pushq %rax ; /* phys int frame / cs */ \
452 pushq 3*8(%rsp) ; /* original caller eip */ \
453 subq $TF_RIP,%rsp ; /* trap frame */ \
454 movq $0,TF_XFLAGS(%rsp) ; /* extras */ \
455 movq $0,TF_TRAPNO(%rsp) ; /* extras */ \
456 movq $0,TF_ADDR(%rsp) ; /* extras */ \
457 movq $0,TF_FLAGS(%rsp) ; /* extras */ \
458 movq $0,TF_ERR(%rsp) ; /* extras */ \
461 addq $TF_RIP+(3*8),%rsp ; \
464 pushq %rbp /* frame for backtrace */
467 pushq %rcx /* last part of intrframe = intr */
468 incl fastunpend_count
469 movq %rsp,%rdi /* pass frame by reference C arg */
470 call ithread_fast_handler /* returns 0 to unmask */
471 popq %rdi /* intrframe->trapframe */
472 /* + also rdi C arg to next call */
475 movq MachIntrABI + MACHINTR_INTREN, %rax
476 callq *%rax /* MachIntrABI.intren(intr) */