2 * Copyright (c) 1989, 1990 William F. Jolitz.
3 * Copyright (c) 1990 The Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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13 * notice, this list of conditions and the following disclaimer.
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18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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39 * $FreeBSD: src/sys/i386/isa/ipl.s,v 1.32.2.3 2002/05/16 16:03:56 bde Exp $
40 * $DragonFly: src/sys/platform/pc32/isa/ipl.s,v 1.26 2005/12/06 02:02:24 dillon Exp $
45 #include <machine/asmacros.h>
46 #include <machine/segments.h>
47 #include <machine/ipl.h>
48 #include <machine/lock.h>
49 #include <machine/psl.h>
50 #include <machine/trap.h>
56 * Vector interrupt control section
58 * ipending - Pending interrupts (set when a masked interrupt occurs)
59 * spending - Pending software interrupts
64 .globl fastunpend_count
65 fastunpend_count: .long 0
73 * - fast interrupts are always called with a critical section
76 * - we release our critical section when scheduling interrupt
77 * or softinterrupt threads in order so they can preempt
78 * (unless we are called manually from a critical section, in
79 * which case there will still be a critical section and
80 * they won't preempt anyway).
82 * - TD_NEST_COUNT prevents splz from nesting too deeply within
83 * itself. It is *not* actually an interrupt nesting count.
84 * PCPU(intr_nesting_level) is an interrupt nesting count.
86 * - We have to be careful in regards to local interrupts
87 * occuring simultaniously with our doreti and splz
94 * Handle return from interrupts, traps and syscalls. This function
95 * checks the cpl for unmasked pending interrupts (fast, normal, or
96 * soft) and schedules them if appropriate, then irets.
98 * If we are in a critical section we cannot run any pending ints
99 * nor can be play with mp_lock.
101 * NOTE: Since SPLs no longer exist, all callers of this function
102 * push $0 for the CPL. HOWEVER, we *STILL* use the cpl mask within
103 * this function to mark fast interrupts which could not be dispatched
104 * do to the unavailability of the BGL.
108 .type doreti,@function
110 FAKE_MCOUNT(bintr) /* init "from" bintr -> doreti */
111 popl %eax /* cpl to restore XXX */
112 movl $0,%eax /* irq mask unavailable due to BGL */
113 movl PCPU(curthread),%ebx
114 cli /* interlock with TDPRI_CRIT */
115 cmpl $0,PCPU(reqflags) /* short cut if nothing to do */
117 cmpl $TDPRI_CRIT,TD_PRI(%ebx) /* can't unpend if in critical sec */
119 addl $TDPRI_CRIT,TD_PRI(%ebx) /* force all ints to pending */
121 sti /* allow new interrupts */
122 movl %eax,%ecx /* irq mask unavailable due to BGL */
124 cli /* disallow YYY remove */
126 testl $RQF_IPIQ,PCPU(reqflags)
129 testl PCPU(fpending),%ecx /* check for an unmasked fast int */
132 testl PCPU(ipending),%ecx /* check for an unmasked slow int */
135 movl PCPU(spending),%ecx /* check for a pending software int */
139 testl $RQF_AST_MASK,PCPU(reqflags) /* any pending ASTs? */
141 testl $PSL_VM,TF_EFLAGS(%esp)
143 cmpl $1,in_vm86call /* YYY make per 'cpu'? */
146 /* ASTs are only applicable when returning to userland */
147 testb $SEL_RPL_MASK,TF_CS(%esp)
151 * Nothing left to do, finish up. Interrupts are still disabled.
152 * %eax contains the mask of IRQ's that are not available due to
153 * BGL requirements. We can only clear RQF_INTPEND if *ALL* pending
154 * interrupts have been processed.
156 subl $TDPRI_CRIT,TD_PRI(%ebx) /* interlocked with cli */
159 andl $~RQF_INTPEND,PCPU(reqflags)
162 .globl doreti_popl_fs
163 .globl doreti_popl_es
164 .globl doreti_popl_ds
166 .globl doreti_syscall_ret
180 .globl doreti_iret_fault
185 .globl doreti_popl_ds_fault
186 doreti_popl_ds_fault:
188 .globl doreti_popl_es_fault
189 doreti_popl_es_fault:
191 .globl doreti_popl_fs_fault
192 doreti_popl_fs_fault:
193 movl $0,TF_ERR(%esp) /* XXX should be the error code */
194 movl $T_PROTFLT,TF_TRAPNO(%esp)
195 jmp alltraps_with_regs_pushed
198 * FAST interrupt pending. NOTE: stack context holds frame structure
199 * for fast interrupt procedure, do not do random pushes or pops!
203 andl PCPU(fpending),%ecx /* only check fast ints */
204 bsfl %ecx, %ecx /* locate the next dispatchable int */
205 btrl %ecx, PCPU(fpending) /* is it really still pending? */
207 pushl %eax /* save IRQ mask unavailable for BGL */
208 /* NOTE: is also CPL in frame */
211 pushl %ecx /* save ecx */
216 /* MP lock successful */
219 incl PCPU(intr_nesting_level)
220 call dofastunpend /* unpend fast intr %ecx */
221 decl PCPU(intr_nesting_level)
230 btsl %ecx, PCPU(fpending) /* oops, couldn't get the MP lock */
231 popl %eax /* add to temp. cpl mask to ignore */
232 orl PCPU(fpending),%eax
236 * INTR interrupt pending
238 * Temporarily back-out our critical section to allow an interrupt
239 * preempt us when we schedule it. Bump intr_nesting_level to
240 * prevent the switch code from recursing via splz too deeply.
244 andl PCPU(ipending),%ecx /* only check normal ints */
245 bsfl %ecx, %ecx /* locate the next dispatchable int */
246 btrl %ecx, PCPU(ipending) /* is it really still pending? */
250 incl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
251 subl $TDPRI_CRIT,TD_PRI(%ebx) /* so we can preempt */
252 call sched_ithd /* YYY must pull in imasks */
253 addl $TDPRI_CRIT,TD_PRI(%ebx)
254 decl TD_NEST_COUNT(%ebx)
260 * SOFT interrupt pending
262 * Temporarily back-out our critical section to allow an interrupt
263 * preempt us when we schedule it. Bump intr_nesting_level to
264 * 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 */
274 incl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
275 subl $TDPRI_CRIT,TD_PRI(%ebx) /* so we can preempt */
276 call sched_ithd /* YYY must pull in imasks */
277 addl $TDPRI_CRIT,TD_PRI(%ebx)
278 decl TD_NEST_COUNT(%ebx)
284 * AST pending. We clear RQF_AST_SIGNAL automatically, the others
285 * are cleared by the trap as they are processed.
287 * Temporarily back-out our critical section because trap() can be
288 * a long-winded call, and we want to be more syscall-like.
290 * YYY theoretically we can call lwkt_switch directly if all we need
291 * to do is a reschedule.
294 andl $~(RQF_AST_SIGNAL|RQF_AST_UPCALL),PCPU(reqflags)
296 movl %eax,%esi /* save cpl (can't use stack) */
297 movl $T_ASTFLT,TF_TRAPNO(%esp)
298 subl $TDPRI_CRIT,TD_PRI(%ebx)
300 addl $TDPRI_CRIT,TD_PRI(%ebx)
301 movl %esi,%eax /* restore cpl for loop */
306 * IPIQ message pending. We clear RQF_IPIQ automatically.
309 movl %eax,%esi /* save cpl (can't use stack) */
310 incl PCPU(intr_nesting_level)
311 andl $~RQF_IPIQ,PCPU(reqflags)
312 subl $8,%esp /* add dummy vec and ppl */
313 call lwkt_process_ipiq_frame
315 decl PCPU(intr_nesting_level)
316 movl %esi,%eax /* restore cpl for loop */
322 * SPLZ() a C callable procedure to dispatch any unmasked pending
323 * interrupts regardless of critical section nesting. ASTs
324 * are not dispatched.
326 * Use %eax to track those IRQs that could not be processed
327 * due to BGL requirements.
334 movl PCPU(curthread),%ebx
335 addl $TDPRI_CRIT,TD_PRI(%ebx)
340 movl %eax,%ecx /* ecx = ~CPL */
343 testl $RQF_IPIQ,PCPU(reqflags)
346 testl PCPU(fpending),%ecx /* check for an unmasked fast int */
349 testl PCPU(ipending),%ecx
352 movl PCPU(spending),%ecx
356 subl $TDPRI_CRIT,TD_PRI(%ebx)
359 * Nothing left to do, finish up. Interrupts are still disabled.
360 * If our mask of IRQs we couldn't process due to BGL requirements
361 * is 0 then there are no pending interrupt sources left and we
362 * can clear RQF_INTPEND.
366 andl $~RQF_INTPEND,PCPU(reqflags)
373 * FAST interrupt pending
377 andl PCPU(fpending),%ecx /* only check fast ints */
378 bsfl %ecx, %ecx /* locate the next dispatchable int */
379 btrl %ecx, PCPU(fpending) /* is it really still pending? */
391 incl PCPU(intr_nesting_level)
392 call dofastunpend /* unpend fast intr %ecx */
393 decl PCPU(intr_nesting_level)
402 btsl %ecx, PCPU(fpending) /* oops, couldn't get the MP lock */
404 orl PCPU(fpending),%eax
408 * INTR interrupt pending
410 * Temporarily back-out our critical section to allow the interrupt
415 andl PCPU(ipending),%ecx /* only check normal ints */
416 bsfl %ecx, %ecx /* locate the next dispatchable int */
417 btrl %ecx, PCPU(ipending) /* is it really still pending? */
422 subl $TDPRI_CRIT,TD_PRI(%ebx)
423 incl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
424 call sched_ithd /* YYY must pull in imasks */
425 addl $TDPRI_CRIT,TD_PRI(%ebx)
426 decl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
432 * SOFT interrupt pending
434 * Temporarily back-out our critical section to allow the interrupt
439 bsfl %ecx,%ecx /* locate the next pending softint */
440 btrl %ecx,PCPU(spending) /* make sure its still pending */
442 addl $FIRST_SOFTINT,%ecx /* actual intr number */
446 subl $TDPRI_CRIT,TD_PRI(%ebx)
447 incl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
448 call sched_ithd /* YYY must pull in imasks */
449 addl $TDPRI_CRIT,TD_PRI(%ebx)
450 decl TD_NEST_COUNT(%ebx) /* prevent doreti/splz nesting */
457 andl $~RQF_IPIQ,PCPU(reqflags)
459 call lwkt_process_ipiq
465 * dofastunpend(%ecx:intr)
467 * A FAST interrupt previously made pending can now be run,
468 * execute it by pushing a dummy interrupt frame and
469 * calling ithread_fast_handler to execute or schedule it.
471 * ithread_fast_handler() returns 0 if it wants us to unmask
472 * further interrupts.
475 pushfl ; /* phys int frame / flags */ \
476 pushl %cs ; /* phys int frame / cs */ \
477 pushl 12(%esp) ; /* original caller eip */ \
478 pushl $0 ; /* dummy error code */ \
479 pushl $0 ; /* dummy trap type */ \
480 subl $12*4,%esp ; /* pushal + 3 seg regs (dummy) + CPL */ \
486 pushl %ebp /* frame for backtrace */
489 pushl %ecx /* last part of intrframe = intr */
490 incl fastunpend_count
491 call ithread_fast_handler /* returns 0 to unmask */
494 movl MachIntrABI + MACHINTR_INTREN, %eax
495 call *%eax /* MachIntrABI.intren(intr) */