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. Neither the name of the University nor the names of its contributors
52 * may be used to endorse or promote products derived from this software
53 * without specific prior written permission.
55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * $FreeBSD: src/sys/i386/isa/ipl.s,v 1.32.2.3 2002/05/16 16:03:56 bde Exp $
72 #include <machine/asmacros.h>
73 #include <machine/segments.h>
74 #include <machine/ipl.h>
75 #include <machine/lock.h>
76 #include <machine/psl.h>
77 #include <machine/trap.h>
83 * Vector interrupt control section
85 * ipending - Pending interrupts (set when a masked interrupt occurs)
86 * spending - Pending software interrupts
91 .globl fastunpend_count
92 fastunpend_count: .long 0
100 * - interrupts are always called with a critical section held
102 * - we release our critical section when scheduling interrupt
103 * or softinterrupt threads in order so they can preempt
104 * (unless we are called manually from a critical section, in
105 * which case there will still be a critical section and
106 * they won't preempt anyway).
108 * - TD_NEST_COUNT prevents splz from nesting too deeply within
109 * itself. It is *not* actually an interrupt nesting count.
110 * PCPU(intr_nesting_level) is an interrupt nesting count.
112 * - We have to be careful in regards to local interrupts
113 * occuring simultaniously with our doreti and splz
116 * - Interrupts must be enabled when calling higher level
117 * functions in order to avoid deadlocking against things
124 * Handle return from interrupts, traps and syscalls. This function
125 * checks the cpl for unmasked pending interrupts (hardware or soft)
126 * and schedules them if appropriate, then irets.
128 * If we are in a critical section we cannot run any pending ints.
130 * The stack contains a trapframe at the start of doreti.
134 .type doreti,@function
136 FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */
137 movq $0,%rax /* irq mask unavailable due to BGL */
138 movq PCPU(curthread),%rbx
139 cli /* interlock with critical section */
140 cmpl $0,PCPU(reqflags) /* short cut if nothing to do */
142 testl $-1,TD_CRITCOUNT(%rbx) /* can't unpend if in critical sec */
144 incl TD_CRITCOUNT(%rbx) /* force all ints to pending */
146 cli /* re-assert cli on loop */
147 movq %rax,%rcx /* irq mask unavailable due to BGL */
149 testl $RQF_IPIQ,PCPU(reqflags)
151 testl $RQF_TIMER,PCPU(reqflags)
154 * check for an unmasked int (3 groups)
157 testq PCPU_E8(ipending,%rdx),%rcx
161 testq PCPU_E8(ipending,%rdx),%rcx
165 testq PCPU_E8(ipending,%rdx),%rcx
168 movl PCPU(spending),%ecx /* check for a pending software int */
172 testl $RQF_AST_MASK,PCPU(reqflags) /* any pending ASTs? */
175 /* ASTs are only applicable when returning to userland */
176 testb $SEL_RPL_MASK,TF_CS(%rsp)
180 * Nothing left to do, finish up. Interrupts are still disabled.
181 * %eax contains the mask of IRQ's that are not available due to
182 * BGL requirements. We can only clear RQF_INTPEND if *ALL* pending
183 * interrupts have been processed.
185 decl TD_CRITCOUNT(%rbx) /* interlocked with cli */
188 andl $~RQF_INTPEND,PCPU(reqflags)
193 * (interrupts are disabled here)
195 * Restore register and iret. iret can fault on %rip (which is
196 * really stupid). If this occurs we re-fault and vector to
197 * doreti_iret_fault().
200 * can be set from user mode, this can result in a kernel mode
201 * exception. The trap code will revector to the *_fault code
202 * which then sets up a T_PROTFLT signal. If the signal is
203 * sent to userland, sendsig() will automatically clean up all
204 * the segment registers to avoid a loop.
207 .globl doreti_syscall_ret
209 POP_FRAME /* registers and %gs (+cli) */
210 /* WARNING: special global doreti_iret is also used by exception.S */
215 * doreti_iret_fault. Alternative return code for the case where
216 * we get a fault in the doreti_exit code above. trap()
217 * (sys/platform/pc64/x86_64/trap.c) catches this specific * case,
218 * sends the process a signal and continues in the corresponding
219 * place in the code below.
221 * Interrupts are likely disabled due to the above interlock
222 * between cli/iretq. We must enable them before calling any
223 * high level function.
226 .globl doreti_iret_fault
230 movq $T_PROTFLT,TF_TRAPNO(%rsp)
231 movq $0,TF_ERR(%rsp) /* XXX should be the error code */
232 movq $0,TF_ADDR(%rsp)
233 FAKE_MCOUNT(TF_RIP(%rsp))
237 * Interrupt pending. NOTE: stack context holds frame structure
238 * for interrupt procedure, do not do random pushes or pops!
242 andq PCPU_E8(ipending,%rdx),%rcx
244 bsfq %rcx, %rcx /* locate the next dispatchable int */
245 btrq %rcx, PCPU_E8(ipending,%rdx)
246 /* is it really still pending? */
250 orq %rdx, %rcx /* form intr number */
252 pushq %rax /* save IRQ mask unavailable for BGL */
253 /* NOTE: is also CPL in frame */
254 call dofastunpend /* unpend intr %rcx */
259 * SOFT interrupt pending
261 * Temporarily back-out our critical section to allow an interrupt
262 * preempt us when we schedule it. Bump intr_nesting_level to
263 * prevent the switch code from recursing via splz too deeply.
268 bsfl %ecx,%ecx /* locate the next pending softint */
269 btrl %ecx,PCPU(spending) /* make sure its still pending */
271 addl $FIRST_SOFTINT,%ecx /* actual intr number */
273 movl %ecx,%edi /* argument to C call */
274 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
275 decl TD_CRITCOUNT(%rbx) /* so we can preempt */
276 call sched_ithd_soft /* YYY must pull in imasks */
277 incl TD_CRITCOUNT(%rbx)
278 decl TD_NEST_COUNT(%rbx)
283 * AST pending. We clear RQF_AST_SIGNAL automatically, the others
284 * are cleared by the trap as they are processed.
286 * Temporarily back-out our critical section because trap() can be
287 * a long-winded call, and we want to be more syscall-like.
289 * YYY theoretically we can call lwkt_switch directly if all we need
290 * to do is a reschedule.
293 andl $~RQF_AST_SIGNAL,PCPU(reqflags)
295 movl %eax,%r12d /* save cpl (can't use stack) */
296 movl $T_ASTFLT,TF_TRAPNO(%rsp)
297 movq %rsp,%rdi /* pass frame by ref (%edi = C arg) */
298 decl TD_CRITCOUNT(%rbx)
300 incl TD_CRITCOUNT(%rbx)
301 movl %r12d,%eax /* restore cpl for loop */
305 * IPIQ message pending. We clear RQF_IPIQ automatically.
308 movl %eax,%r12d /* save cpl (can't use stack) */
309 incl PCPU(intr_nesting_level)
310 andl $~RQF_IPIQ,PCPU(reqflags)
312 subq $8,%rsp /* trapframe->intrframe */
313 movq %rsp,%rdi /* pass frame by ref (C arg) */
314 call lwkt_process_ipiq_frame
315 addq $8,%rsp /* intrframe->trapframe */
316 decl PCPU(intr_nesting_level)
317 movl %r12d,%eax /* restore cpl for loop */
321 movl %eax,%r12d /* save cpl (can't use stack) */
322 incl PCPU(intr_nesting_level)
323 andl $~RQF_TIMER,PCPU(reqflags)
325 subq $8,%rsp /* trapframe->intrframe */
326 movq %rsp,%rdi /* pass frame by ref (C arg) */
327 call pcpu_timer_process_frame
328 addq $8,%rsp /* intrframe->trapframe */
329 decl PCPU(intr_nesting_level)
330 movl %r12d,%eax /* restore cpl for loop */
334 * SPLZ() a C callable procedure to dispatch any unmasked pending
335 * interrupts regardless of critical section nesting. ASTs
336 * are not dispatched.
338 * Use %eax to track those IRQs that could not be processed
339 * due to BGL requirements.
346 movq PCPU(curthread),%rbx
347 incl TD_CRITCOUNT(%rbx)
352 movq %rax,%rcx /* rcx = ~CPL */
354 testl $RQF_IPIQ,PCPU(reqflags)
356 testl $RQF_TIMER,PCPU(reqflags)
359 * check for an unmasked int (3 groups)
362 testq PCPU_E8(ipending,%rdx),%rcx
366 testq PCPU_E8(ipending,%rdx),%rcx
370 testq PCPU_E8(ipending,%rdx),%rcx
373 movl PCPU(spending),%ecx
377 decl TD_CRITCOUNT(%rbx)
380 * Nothing left to do, finish up. Interrupts are still disabled.
381 * If our mask of IRQs we couldn't process due to BGL requirements
382 * is 0 then there are no pending interrupt sources left and we
383 * can clear RQF_INTPEND.
387 andl $~RQF_INTPEND,PCPU(reqflags)
398 andq PCPU_E8(ipending,%rdx),%rcx
400 bsfq %rcx, %rcx /* locate the next dispatchable int */
401 btrq %rcx, PCPU_E8(ipending,%rdx)
402 /* is it really still pending? */
406 orq %rdx, %rcx /* form intr number */
409 call dofastunpend /* unpend intr %rcx */
414 * SOFT interrupt pending
416 * Temporarily back-out our critical section to allow the interrupt
422 bsfl %ecx,%ecx /* locate the next pending softint */
423 btrl %ecx,PCPU(spending) /* make sure its still pending */
425 addl $FIRST_SOFTINT,%ecx /* actual intr number */
428 movl %ecx,%edi /* C argument */
429 incl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
430 decl TD_CRITCOUNT(%rbx)
431 call sched_ithd_soft /* YYY must pull in imasks */
432 incl TD_CRITCOUNT(%rbx)
433 decl TD_NEST_COUNT(%rbx) /* prevent doreti/splz nesting */
438 andl $~RQF_IPIQ,PCPU(reqflags)
441 call lwkt_process_ipiq
446 andl $~RQF_TIMER,PCPU(reqflags)
449 call pcpu_timer_process
454 * dofastunpend(%rcx:intr)
456 * A interrupt previously made pending can now be run,
457 * execute it by pushing a dummy interrupt frame and
458 * calling ithread_fast_handler to execute or schedule it.
460 * ithread_fast_handler() returns 0 if it wants us to unmask
461 * further interrupts.
464 pushfq ; /* phys int frame / flags */ \
465 xorq %rax,%rax ; /* something not SEL_UPL */ \
466 pushq %rax ; /* phys int frame / cs */ \
467 pushq 3*8(%rsp) ; /* original caller eip */ \
468 subq $TF_RIP,%rsp ; /* trap frame */ \
469 movq $0,TF_XFLAGS(%rsp) ; /* extras */ \
470 movq $0,TF_TRAPNO(%rsp) ; /* extras */ \
471 movq $0,TF_ADDR(%rsp) ; /* extras */ \
472 movq $0,TF_FLAGS(%rsp) ; /* extras */ \
473 movq $0,TF_ERR(%rsp) ; /* extras */ \
476 addq $TF_RIP+(3*8),%rsp ; \
479 pushq %rbp /* frame for backtrace */
482 pushq %rcx /* last part of intrframe = intr */
483 incl fastunpend_count
484 movq %rsp,%rdi /* pass frame by reference C arg */
485 call ithread_fast_handler /* returns 0 to unmask */
486 popq %rdi /* intrframe->trapframe */
487 /* + also rdi C arg to next call */
490 movq MachIntrABI + MACHINTR_INTREN, %rax
491 callq *%rax /* MachIntrABI.intren(intr) */