Annotation of src/sys/arch/i386/i386/locore.S, Revision 1.25
1.25 ! drochner 1: /* $NetBSD: locore.S,v 1.24 2004/02/20 17:35:01 yamt Exp $ */
1.1 fvdl 2:
3: /*-
4: * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Charles M. Hannum.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the NetBSD
21: * Foundation, Inc. and its contributors.
22: * 4. Neither the name of The NetBSD Foundation nor the names of its
23: * contributors may be used to endorse or promote products derived
24: * from this software without specific prior written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: /*-
40: * Copyright (c) 1990 The Regents of the University of California.
41: * All rights reserved.
42: *
43: * This code is derived from software contributed to Berkeley by
44: * William Jolitz.
45: *
46: * Redistribution and use in source and binary forms, with or without
47: * modification, are permitted provided that the following conditions
48: * are met:
49: * 1. Redistributions of source code must retain the above copyright
50: * notice, this list of conditions and the following disclaimer.
51: * 2. Redistributions in binary form must reproduce the above copyright
52: * notice, this list of conditions and the following disclaimer in the
53: * documentation and/or other materials provided with the distribution.
1.12 agc 54: * 3. Neither the name of the University nor the names of its contributors
1.1 fvdl 55: * may be used to endorse or promote products derived from this software
56: * without specific prior written permission.
57: *
58: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68: * SUCH DAMAGE.
69: *
70: * @(#)locore.s 7.3 (Berkeley) 5/13/91
71: */
72:
1.18 christos 73: #include "opt_compat_netbsd.h"
74: #include "opt_compat_oldboot.h"
1.1 fvdl 75: #include "opt_cputype.h"
76: #include "opt_ddb.h"
77: #include "opt_ipkdb.h"
1.18 christos 78: #include "opt_lockdebug.h"
1.1 fvdl 79: #include "opt_multiprocessor.h"
80: #include "opt_realmem.h"
1.18 christos 81: #include "opt_user_ldt.h"
82: #include "opt_vm86.h"
1.1 fvdl 83:
84: #include "npx.h"
85: #include "assym.h"
86: #include "apm.h"
87: #include "lapic.h"
88: #include "ioapic.h"
1.8 fvdl 89: #include "ksyms.h"
1.1 fvdl 90:
91: #include <sys/errno.h>
92: #include <sys/syscall.h>
93:
94: #include <machine/cputypes.h>
95: #include <machine/param.h>
96: #include <machine/pte.h>
97: #include <machine/segments.h>
98: #include <machine/specialreg.h>
99: #include <machine/trap.h>
100: #include <machine/bootinfo.h>
101:
102: #if NLAPIC > 0
103: #include <machine/i82489reg.h>
104: #endif
105:
106: /* LINTSTUB: include <sys/types.h> */
107: /* LINTSTUB: include <machine/cpu.h> */
108: /* LINTSTUB: include <sys/systm.h> */
109:
110: #include <machine/asm.h>
111:
112: #if defined(MULTIPROCESSOR)
113:
1.5 thorpej 114: #define SET_CURLWP(lwp,cpu) \
1.1 fvdl 115: movl CPUVAR(SELF),cpu ; \
1.5 thorpej 116: movl lwp,CPUVAR(CURLWP) ; \
117: movl cpu,L_CPU(lwp)
1.1 fvdl 118:
119: #else
120:
1.5 thorpej 121: #define SET_CURLWP(lwp,tcpu) movl lwp,CPUVAR(CURLWP)
122: #define GET_CURLWP(reg) movl CPUVAR(CURLWP),reg
1.1 fvdl 123:
124: #endif
125:
126: #define GET_CURPCB(reg) movl CPUVAR(CURPCB),reg
127: #define SET_CURPCB(reg) movl reg,CPUVAR(CURPCB)
1.24 yamt 128:
1.1 fvdl 129: #define CLEAR_RESCHED(reg) movl reg,CPUVAR(RESCHED)
130:
131: /* XXX temporary kluge; these should not be here */
132: /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */
133: #include <dev/isa/isareg.h>
134:
135:
136: /* Disallow old names for REALBASEMEM */
137: #ifdef BIOSBASEMEM
138: #error BIOSBASEMEM option deprecated; use REALBASEMEM only if memory size reported by latest boot block is incorrect
139: #endif
140:
141: /* Disallow old names for REALEXTMEM */
142: #ifdef EXTMEM_SIZE
143: #error EXTMEM_SIZE option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
144: #endif
145: #ifdef BIOSEXTMEM
146: #error BIOSEXTMEM option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
147: #endif
148:
149: #include <machine/frameasm.h>
150:
151:
152: #ifdef MULTIPROCESSOR
153: #include <machine/i82489reg.h>
154: #endif
155:
156: /*
157: * PTmap is recursive pagemap at top of virtual address space.
158: * Within PTmap, the page directory can be found (third indirection).
159: *
160: * XXX 4 == sizeof pde
161: */
162: .set _C_LABEL(PTmap),(PDSLOT_PTE << PDSHIFT)
1.7 thorpej 163: .set _C_LABEL(PTD),(_C_LABEL(PTmap) + PDSLOT_PTE * PAGE_SIZE)
1.1 fvdl 164: .set _C_LABEL(PTDpde),(_C_LABEL(PTD) + PDSLOT_PTE * 4)
165:
166: /*
167: * APTmap, APTD is the alternate recursive pagemap.
168: * It's used when modifying another process's page tables.
169: *
170: * XXX 4 == sizeof pde
171: */
172: .set _C_LABEL(APTmap),(PDSLOT_APTE << PDSHIFT)
1.7 thorpej 173: .set _C_LABEL(APTD),(_C_LABEL(APTmap) + PDSLOT_APTE * PAGE_SIZE)
1.1 fvdl 174: .set _C_LABEL(APTDpde),(_C_LABEL(PTD) + PDSLOT_APTE * 4)
175:
176:
177: /*
178: * Initialization
179: */
180: .data
181:
182: .globl _C_LABEL(cpu)
183: .globl _C_LABEL(esym),_C_LABEL(boothowto)
184: .globl _C_LABEL(bootinfo),_C_LABEL(atdevbase)
185: #ifdef COMPAT_OLDBOOT
186: .globl _C_LABEL(bootdev)
187: #endif
188: .globl _C_LABEL(proc0paddr),_C_LABEL(PTDpaddr)
189: .globl _C_LABEL(biosbasemem),_C_LABEL(biosextmem)
190: .globl _C_LABEL(gdt)
191: #ifdef I586_CPU
192: .globl _C_LABEL(idt)
193: #endif
194: .globl _C_LABEL(lapic_tpr)
195:
196: #if NLAPIC > 0
197: #ifdef __ELF__
1.7 thorpej 198: .align PAGE_SIZE
1.1 fvdl 199: #else
200: .align 12
201: #endif
202: .globl _C_LABEL(local_apic), _C_LABEL(lapic_id)
203: _C_LABEL(local_apic):
204: .space LAPIC_ID
205: _C_LABEL(lapic_id):
206: .long 0x00000000
207: .space LAPIC_TPRI-(LAPIC_ID+4)
208: _C_LABEL(lapic_tpr):
209: .space LAPIC_PPRI-LAPIC_TPRI
210: _C_LABEL(lapic_ppr):
211: .space LAPIC_ISR-LAPIC_PPRI
212: _C_LABEL(lapic_isr):
1.7 thorpej 213: .space PAGE_SIZE-LAPIC_ISR
1.1 fvdl 214: #else
215: _C_LABEL(lapic_tpr):
216: .long 0
217: #endif
218:
219:
220: _C_LABEL(cpu): .long 0 # are we 386, 386sx, or 486,
221: # or Pentium, or..
222: _C_LABEL(esym): .long 0 # ptr to end of syms
223: _C_LABEL(atdevbase): .long 0 # location of start of iomem in virtual
224: _C_LABEL(proc0paddr): .long 0
225: _C_LABEL(PTDpaddr): .long 0 # paddr of PTD, for libkvm
226: #ifndef REALBASEMEM
227: _C_LABEL(biosbasemem): .long 0 # base memory reported by BIOS
228: #else
229: _C_LABEL(biosbasemem): .long REALBASEMEM
230: #endif
231: #ifndef REALEXTMEM
232: _C_LABEL(biosextmem): .long 0 # extended memory reported by BIOS
233: #else
234: _C_LABEL(biosextmem): .long REALEXTMEM
235: #endif
236:
237: .space 512
238: tmpstk:
239:
240:
1.13 christos 241: #define _RELOC(x) ((x) - KERNBASE_LOCORE)
1.1 fvdl 242: #define RELOC(x) _RELOC(_C_LABEL(x))
243:
244: .text
245: .globl _C_LABEL(kernel_text)
246: .set _C_LABEL(kernel_text),KERNTEXTOFF
247:
248: .globl start
249: start: movw $0x1234,0x472 # warm boot
250:
251: /*
252: * Load parameters from stack
253: * (howto, [bootdev], bootinfo, esym, basemem, extmem).
254: */
255: movl 4(%esp),%eax
256: movl %eax,RELOC(boothowto)
257: #ifdef COMPAT_OLDBOOT
258: movl 8(%esp),%eax
259: movl %eax,RELOC(bootdev)
260: #endif
261: movl 12(%esp),%eax
262:
263: testl %eax, %eax
264: jz 1f
265: movl (%eax), %ebx /* number of entries */
266: movl $RELOC(bootinfo), %edi
267: movl %ebx, (%edi)
268: addl $4, %edi
269: 2:
270: testl %ebx, %ebx
271: jz 1f
272: addl $4, %eax
273: movl (%eax), %ecx /* address of entry */
274: pushl %eax
275: pushl (%ecx) /* len */
276: pushl %ecx
277: pushl %edi
278: addl (%ecx), %edi /* update dest pointer */
279: cmpl $_RELOC(_C_LABEL(bootinfo) + BOOTINFO_MAXSIZE), %edi
280: jg 2f
281: call _C_LABEL(memcpy)
282: addl $12, %esp
283: popl %eax
284: subl $1, %ebx
285: jmp 2b
286: 2: /* cleanup for overflow case */
287: addl $16, %esp
288: movl $RELOC(bootinfo), %edi
289: subl %ebx, (%edi) /* correct number of entries */
290: 1:
291:
292: movl 16(%esp),%eax
293: testl %eax,%eax
294: jz 1f
1.13 christos 295: addl $KERNBASE_LOCORE,%eax
1.1 fvdl 296: 1: movl %eax,RELOC(esym)
297:
298: movl RELOC(biosextmem),%eax
299: testl %eax,%eax
300: jnz 1f
301: movl 20(%esp),%eax
302: movl %eax,RELOC(biosextmem)
303: 1:
304: movl RELOC(biosbasemem),%eax
305: testl %eax,%eax
306: jnz 1f
307: movl 24(%esp),%eax
308: movl %eax,RELOC(biosbasemem)
309: 1:
310:
311: /* First, reset the PSL. */
312: pushl $PSL_MBO
313: popfl
314:
315: /* Clear segment registers; always null in proc0. */
316: xorl %eax,%eax
317: movw %ax,%fs
318: movw %ax,%gs
319: decl %eax
320: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
321:
322: /* Find out our CPU type. */
323:
324: try386: /* Try to toggle alignment check flag; does not exist on 386. */
325: pushfl
326: popl %eax
327: movl %eax,%ecx
328: orl $PSL_AC,%eax
329: pushl %eax
330: popfl
331: pushfl
332: popl %eax
333: xorl %ecx,%eax
334: andl $PSL_AC,%eax
335: pushl %ecx
336: popfl
337:
338: testl %eax,%eax
339: jnz try486
340:
341: /*
342: * Try the test of a NexGen CPU -- ZF will not change on a DIV
343: * instruction on a NexGen, it will on an i386. Documented in
344: * Nx586 Processor Recognition Application Note, NexGen, Inc.
345: */
346: movl $0x5555,%eax
347: xorl %edx,%edx
348: movl $2,%ecx
349: divl %ecx
350: jnz is386
351:
352: isnx586:
353: /*
354: * Don't try cpuid, as Nx586s reportedly don't support the
355: * PSL_ID bit.
356: */
357: movl $CPU_NX586,RELOC(cpu)
358: jmp 2f
359:
360: is386:
361: movl $CPU_386,RELOC(cpu)
362: jmp 2f
363:
364: try486: /* Try to toggle identification flag; does not exist on early 486s. */
365: pushfl
366: popl %eax
367: movl %eax,%ecx
368: xorl $PSL_ID,%eax
369: pushl %eax
370: popfl
371: pushfl
372: popl %eax
373: xorl %ecx,%eax
374: andl $PSL_ID,%eax
375: pushl %ecx
376: popfl
377:
378: testl %eax,%eax
379: jnz try586
380: is486: movl $CPU_486,RELOC(cpu)
381: /*
382: * Check Cyrix CPU
383: * Cyrix CPUs do not change the undefined flags following
384: * execution of the divide instruction which divides 5 by 2.
385: *
386: * Note: CPUID is enabled on M2, so it passes another way.
387: */
388: pushfl
389: movl $0x5555, %eax
390: xorl %edx, %edx
391: movl $2, %ecx
392: clc
393: divl %ecx
394: jnc trycyrix486
395: popfl
396: jmp 2f
397: trycyrix486:
398: movl $CPU_6x86,RELOC(cpu) # set CPU type
399: /*
400: * Check for Cyrix 486 CPU by seeing if the flags change during a
401: * divide. This is documented in the Cx486SLC/e SMM Programmer's
402: * Guide.
403: */
404: xorl %edx,%edx
405: cmpl %edx,%edx # set flags to known state
406: pushfl
407: popl %ecx # store flags in ecx
408: movl $-1,%eax
409: movl $4,%ebx
410: divl %ebx # do a long division
411: pushfl
412: popl %eax
413: xorl %ecx,%eax # are the flags different?
414: testl $0x8d5,%eax # only check C|PF|AF|Z|N|V
415: jne 2f # yes; must be Cyrix 6x86 CPU
416: movl $CPU_486DLC,RELOC(cpu) # set CPU type
417:
418: #ifndef CYRIX_CACHE_WORKS
419: /* Disable caching of the ISA hole only. */
420: invd
421: movb $CCR0,%al # Configuration Register index (CCR0)
422: outb %al,$0x22
423: inb $0x23,%al
424: orb $(CCR0_NC1|CCR0_BARB),%al
425: movb %al,%ah
426: movb $CCR0,%al
427: outb %al,$0x22
428: movb %ah,%al
429: outb %al,$0x23
430: invd
431: #else /* CYRIX_CACHE_WORKS */
432: /* Set cache parameters */
433: invd # Start with guaranteed clean cache
434: movb $CCR0,%al # Configuration Register index (CCR0)
435: outb %al,$0x22
436: inb $0x23,%al
437: andb $~CCR0_NC0,%al
438: #ifndef CYRIX_CACHE_REALLY_WORKS
439: orb $(CCR0_NC1|CCR0_BARB),%al
440: #else
441: orb $CCR0_NC1,%al
442: #endif
443: movb %al,%ah
444: movb $CCR0,%al
445: outb %al,$0x22
446: movb %ah,%al
447: outb %al,$0x23
448: /* clear non-cacheable region 1 */
449: movb $(NCR1+2),%al
450: outb %al,$0x22
451: movb $NCR_SIZE_0K,%al
452: outb %al,$0x23
453: /* clear non-cacheable region 2 */
454: movb $(NCR2+2),%al
455: outb %al,$0x22
456: movb $NCR_SIZE_0K,%al
457: outb %al,$0x23
458: /* clear non-cacheable region 3 */
459: movb $(NCR3+2),%al
460: outb %al,$0x22
461: movb $NCR_SIZE_0K,%al
462: outb %al,$0x23
463: /* clear non-cacheable region 4 */
464: movb $(NCR4+2),%al
465: outb %al,$0x22
466: movb $NCR_SIZE_0K,%al
467: outb %al,$0x23
468: /* enable caching in CR0 */
469: movl %cr0,%eax
470: andl $~(CR0_CD|CR0_NW),%eax
471: movl %eax,%cr0
472: invd
473: #endif /* CYRIX_CACHE_WORKS */
474:
475: jmp 2f
476:
477: try586: /* Use the `cpuid' instruction. */
478: xorl %eax,%eax
479: cpuid
480: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
481:
482: 2:
483: /*
484: * Finished with old stack; load new %esp now instead of later so we
485: * can trace this code without having to worry about the trace trap
486: * clobbering the memory test or the zeroing of the bss+bootstrap page
487: * tables.
488: *
489: * The boot program should check:
490: * text+data <= &stack_variable - more_space_for_stack
491: * text+data+bss+pad+space_for_page_tables <= end_of_memory
492: * Oops, the gdt is in the carcass of the boot program so clearing
493: * the rest of memory is still not possible.
494: */
495: movl $_RELOC(tmpstk),%esp # bootstrap stack end location
496:
497: /*
498: * Virtual address space of kernel:
499: *
500: * text | data | bss | [syms] | page dir | proc0 kstack
501: * 0 1 2 3
502: */
1.7 thorpej 503: #define PROC0PDIR ((0) * PAGE_SIZE)
504: #define PROC0STACK ((1) * PAGE_SIZE)
505: #define SYSMAP ((1+UPAGES) * PAGE_SIZE)
506: #define TABLESIZE ((1+UPAGES) * PAGE_SIZE) /* + nkpde * PAGE_SIZE */
1.1 fvdl 507:
508: /* Find end of kernel image. */
509: movl $RELOC(end),%edi
1.8 fvdl 510: #if (NKSYMS || defined(DDB) || defined(LKM)) && !defined(SYMTAB_SPACE)
1.1 fvdl 511: /* Save the symbols (if loaded). */
512: movl RELOC(esym),%eax
513: testl %eax,%eax
514: jz 1f
1.13 christos 515: subl $KERNBASE_LOCORE,%eax
1.1 fvdl 516: movl %eax,%edi
517: 1:
518: #endif
519:
520: /* Calculate where to start the bootstrap tables. */
521: movl %edi,%esi # edi = esym ? esym : end
522: addl $PGOFSET,%esi # page align up
523: andl $~PGOFSET,%esi
524:
525: /*
526: * Calculate the size of the kernel page table directory, and
527: * how many entries it will have.
528: */
529: movl RELOC(nkpde),%ecx # get nkpde
530: cmpl $NKPTP_MIN,%ecx # larger than min?
531: jge 1f
532: movl $NKPTP_MIN,%ecx # set at min
533: jmp 2f
534: 1: cmpl $NKPTP_MAX,%ecx # larger than max?
535: jle 2f
536: movl $NKPTP_MAX,%ecx
537: 2:
538:
539: /* Clear memory for bootstrap tables. */
540: shll $PGSHIFT,%ecx
541: addl $TABLESIZE,%ecx
542: addl %esi,%ecx # end of tables
543: subl %edi,%ecx # size of tables
544: shrl $2,%ecx
545: xorl %eax,%eax
546: cld
547: rep
548: stosl
549:
550: /*
551: * fillkpt
552: * eax = pte (page frame | control | status)
553: * ebx = page table address
554: * ecx = number of pages to map
555: */
556: #define fillkpt \
557: 1: movl %eax,(%ebx) ; \
1.7 thorpej 558: addl $PAGE_SIZE,%eax ; /* increment physical address */ \
1.1 fvdl 559: addl $4,%ebx ; /* next pte */ \
560: loop 1b ;
561:
562: /*
563: * Build initial page tables.
564: */
565: /* Calculate end of text segment, rounded to a page. */
566: leal (RELOC(etext)+PGOFSET),%edx
567: andl $~PGOFSET,%edx
568:
569: /* Skip over the first 1MB. */
570: movl $_RELOC(KERNTEXTOFF),%eax
571: movl %eax,%ecx
572: shrl $PGSHIFT,%ecx
573: leal (SYSMAP)(%esi,%ecx,4),%ebx
574:
575: /* Map the kernel text read-only. */
576: movl %edx,%ecx
577: subl %eax,%ecx
578: shrl $PGSHIFT,%ecx
579: orl $(PG_V|PG_KR),%eax
580: fillkpt
581:
582: /* Map the data, BSS, and bootstrap tables read-write. */
583: leal (PG_V|PG_KW)(%edx),%eax
584: movl RELOC(nkpde),%ecx
585: shll $PGSHIFT,%ecx
586: addl $TABLESIZE,%ecx
587: addl %esi,%ecx # end of tables
588: subl %edx,%ecx # subtract end of text
589: shrl $PGSHIFT,%ecx
590: fillkpt
591:
592: /* Map ISA I/O memory. */
593: movl $(IOM_BEGIN|PG_V|PG_KW/*|PG_N*/),%eax # having these bits set
594: movl $(IOM_SIZE>>PGSHIFT),%ecx # for this many pte s,
595: fillkpt
596:
597: /*
598: * Construct a page table directory.
599: */
600: /* Install PDEs for temporary double map of kernel. */
601: movl RELOC(nkpde),%ecx # for this many pde s,
602: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
603: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
604: fillkpt
605:
606: /* Map kernel PDEs. */
607: movl RELOC(nkpde),%ecx # for this many pde s,
608: leal (PROC0PDIR+PDSLOT_KERN*4)(%esi),%ebx # kernel pde offset
609: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
610: fillkpt
611:
612: /* Install a PDE recursively mapping page directory as a page table! */
613: leal (PROC0PDIR+PG_V|PG_KW)(%esi),%eax # pte for ptd
614: movl %eax,(PROC0PDIR+PDSLOT_PTE*4)(%esi) # recursive PD slot
615:
616: /* Save phys. addr of PTD, for libkvm. */
617: movl %esi,RELOC(PTDpaddr)
618:
619: /* Load base of page directory and enable mapping. */
620: movl %esi,%eax # phys address of ptd in proc 0
621: movl %eax,%cr3 # load ptd addr into mmu
622: movl %cr0,%eax # get control word
623: # enable paging & NPX emulation
624: orl $(CR0_PE|CR0_PG|CR0_NE|CR0_TS|CR0_EM|CR0_MP),%eax
625: movl %eax,%cr0 # and let's page NOW!
626:
627: pushl $begin # jump to high mem
628: ret
629:
630: begin:
1.13 christos 631: /* Now running relocated at KERNBASE_LOCORE. Remove double mapping. */
1.1 fvdl 632: movl _C_LABEL(nkpde),%ecx # for this many pde s,
633: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
1.13 christos 634: addl $(KERNBASE_LOCORE), %ebx # now use relocated address
1.1 fvdl 635: 1: movl $0,(%ebx)
636: addl $4,%ebx # next pde
637: loop 1b
638:
639: /* Relocate atdevbase. */
640: movl _C_LABEL(nkpde),%edx
641: shll $PGSHIFT,%edx
1.13 christos 642: addl $(TABLESIZE+KERNBASE_LOCORE),%edx
1.1 fvdl 643: addl %esi,%edx
644: movl %edx,_C_LABEL(atdevbase)
645:
646: /* Set up bootstrap stack. */
1.13 christos 647: leal (PROC0STACK+KERNBASE_LOCORE)(%esi),%eax
1.1 fvdl 648: movl %eax,_C_LABEL(proc0paddr)
649: leal (USPACE-FRAMESIZE)(%eax),%esp
650: movl %esi,PCB_CR3(%eax) # pcb->pcb_cr3
651: xorl %ebp,%ebp # mark end of frames
652:
653: subl $NGDT*8, %esp # space for temporary gdt
654: pushl %esp
655: call _C_LABEL(initgdt)
656: addl $4,%esp
657:
658: movl _C_LABEL(nkpde),%eax
659: shll $PGSHIFT,%eax
660: addl $TABLESIZE,%eax
661: addl %esi,%eax # skip past stack and page tables
662:
663: pushl %eax
664: call _C_LABEL(init386) # wire 386 chip for unix operation
665: addl $4+NGDT*8,%esp # pop temporary gdt
666:
667: #ifdef SAFARI_FIFO_HACK
668: movb $5,%al
669: movw $0x37b,%dx
670: outb %al,%dx
671: movw $0x37f,%dx
672: inb %dx,%al
673: movb %al,%cl
674:
675: orb $1,%cl
676:
677: movb $5,%al
678: movw $0x37b,%dx
679: outb %al,%dx
680: movw $0x37f,%dx
681: movb %cl,%al
682: outb %al,%dx
683: #endif /* SAFARI_FIFO_HACK */
684:
685: call _C_LABEL(main)
686:
687: /*
688: * void proc_trampoline(void);
689: * This is a trampoline function pushed onto the stack of a newly created
690: * process in order to do some additional setup. The trampoline is entered by
691: * cpu_switch()ing to the process, so we abuse the callee-saved registers used
692: * by cpu_switch() to store the information about the stub to call.
693: * NOTE: This function does not have a normal calling sequence!
694: */
695: /* LINTSTUB: Func: void proc_trampoline(void) */
696: NENTRY(proc_trampoline)
697: #ifdef MULTIPROCESSOR
698: call _C_LABEL(proc_trampoline_mp)
699: #endif
700: movl $IPL_NONE,CPUVAR(ILEVEL)
701: pushl %ebx
702: call *%esi
703: addl $4,%esp
1.24 yamt 704: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 705: INTRFASTEXIT
706: /* NOTREACHED */
707:
708: /*****************************************************************************/
1.16 christos 709: #ifdef COMPAT_16
1.1 fvdl 710: /*
711: * Signal trampoline; copied to top of user stack.
712: */
713: /* LINTSTUB: Var: char sigcode[1], esigcode[1]; */
714: NENTRY(sigcode)
715: /*
716: * Handler has returned here as if we called it. The sigcontext
717: * is on the stack after the 3 args "we" pushed.
718: */
719: leal 12(%esp),%eax # get pointer to sigcontext
720: movl %eax,4(%esp) # put it in the argument slot
721: # fake return address already there
1.17 christos 722: movl $SYS_compat_16___sigreturn14,%eax
1.1 fvdl 723: int $0x80 # enter kernel with args on stack
724: movl $SYS_exit,%eax
725: int $0x80 # exit if sigreturn fails
726: .globl _C_LABEL(esigcode)
727: _C_LABEL(esigcode):
1.16 christos 728: #endif
1.1 fvdl 729:
730: /*****************************************************************************/
731:
732: /*
733: * The following primitives are used to fill and copy regions of memory.
734: */
735:
736: /*
737: * XXX No section 9 man page for fillw.
738: * fillw seems to be very sparsely used (only in pccons it seems.)
739: * One wonders if it couldn't be done without.
740: * -- Perry Metzger, May 7, 2001
741: */
742: /*
743: * void fillw(short pattern, void *addr, size_t len);
744: * Write len copies of pattern at addr.
745: */
746: /* LINTSTUB: Func: void fillw(short pattern, void *addr, size_t len) */
747: ENTRY(fillw)
748: pushl %edi
749: movl 8(%esp),%eax
750: movl 12(%esp),%edi
751: movw %ax,%cx
752: rorl $16,%eax
753: movw %cx,%ax
754: cld
755: movl 16(%esp),%ecx
756: shrl %ecx # do longwords
757: rep
758: stosl
759: movl 16(%esp),%ecx
760: andl $1,%ecx # do remainder
761: rep
762: stosw
763: popl %edi
764: ret
765:
766: /*
767: * int kcopy(const void *from, void *to, size_t len);
768: * Copy len bytes, abort on fault.
769: */
770: /* LINTSTUB: Func: int kcopy(const void *from, void *to, size_t len) */
771: ENTRY(kcopy)
772: pushl %esi
773: pushl %edi
774: GET_CURPCB(%eax) # load curpcb into eax and set on-fault
775: pushl PCB_ONFAULT(%eax)
1.24 yamt 776: movl $_C_LABEL(kcopy_fault), PCB_ONFAULT(%eax)
1.1 fvdl 777:
778: movl 16(%esp),%esi
779: movl 20(%esp),%edi
780: movl 24(%esp),%ecx
781: movl %edi,%eax
782: subl %esi,%eax
783: cmpl %ecx,%eax # overlapping?
784: jb 1f
785: cld # nope, copy forward
786: shrl $2,%ecx # copy by 32-bit words
787: rep
788: movsl
789: movl 24(%esp),%ecx
790: andl $3,%ecx # any bytes left?
791: rep
792: movsb
793:
794: GET_CURPCB(%edx) # XXX save curpcb?
795: popl PCB_ONFAULT(%edx)
796: popl %edi
797: popl %esi
798: xorl %eax,%eax
799: ret
800:
801: ALIGN_TEXT
802: 1: addl %ecx,%edi # copy backward
803: addl %ecx,%esi
804: std
805: andl $3,%ecx # any fractional bytes?
806: decl %edi
807: decl %esi
808: rep
809: movsb
810: movl 24(%esp),%ecx # copy remainder by 32-bit words
811: shrl $2,%ecx
812: subl $3,%esi
813: subl $3,%edi
814: rep
815: movsl
816: cld
817:
818: GET_CURPCB(%edx)
819: popl PCB_ONFAULT(%edx)
820: popl %edi
821: popl %esi
822: xorl %eax,%eax
823: ret
824:
825: /*****************************************************************************/
826:
827: /*
828: * The following primitives are used to copy data in and out of the user's
829: * address space.
830: */
831:
832: /*
833: * Default to the lowest-common-denominator. We will improve it
834: * later.
835: */
836: #if defined(I386_CPU)
837: #define DEFAULT_COPYOUT _C_LABEL(i386_copyout)
838: #define DEFAULT_COPYIN _C_LABEL(i386_copyin)
839: #elif defined(I486_CPU)
840: #define DEFAULT_COPYOUT _C_LABEL(i486_copyout)
841: #define DEFAULT_COPYIN _C_LABEL(i386_copyin)
842: #elif defined(I586_CPU)
843: #define DEFAULT_COPYOUT _C_LABEL(i486_copyout) /* XXX */
844: #define DEFAULT_COPYIN _C_LABEL(i386_copyin) /* XXX */
845: #elif defined(I686_CPU)
846: #define DEFAULT_COPYOUT _C_LABEL(i486_copyout) /* XXX */
847: #define DEFAULT_COPYIN _C_LABEL(i386_copyin) /* XXX */
848: #endif
849:
850: .data
851:
852: .globl _C_LABEL(copyout_func)
853: _C_LABEL(copyout_func):
854: .long DEFAULT_COPYOUT
855:
856: .globl _C_LABEL(copyin_func)
857: _C_LABEL(copyin_func):
858: .long DEFAULT_COPYIN
859:
860: .text
861:
862: /*
863: * int copyout(const void *from, void *to, size_t len);
864: * Copy len bytes into the user's address space.
865: * see copyout(9)
866: */
867: /* LINTSTUB: Func: int copyout(const void *kaddr, void *uaddr, size_t len) */
868: ENTRY(copyout)
1.24 yamt 869: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 870: jmp *_C_LABEL(copyout_func)
871:
872: #if defined(I386_CPU)
873: /* LINTSTUB: Func: int i386_copyout(const void *kaddr, void *uaddr, size_t len) */
874: ENTRY(i386_copyout)
875: pushl %esi
876: pushl %edi
877: pushl $0
878:
879: movl 16(%esp),%esi
880: movl 20(%esp),%edi
881: movl 24(%esp),%eax
882:
883: /*
884: * We check that the end of the destination buffer is not past the end
885: * of the user's address space. If it's not, then we only need to
886: * check that each page is writable. The 486 will do this for us; the
887: * 386 will not. (We assume that pages in user space that are not
888: * writable by the user are not writable by the kernel either.)
889: */
890: movl %edi,%edx
891: addl %eax,%edx
892: jc _C_LABEL(copy_efault)
893: cmpl $VM_MAXUSER_ADDRESS,%edx
894: ja _C_LABEL(copy_efault)
895:
896: testl %eax,%eax # anything to do?
897: jz 3f
898:
899: /*
900: * We have to check each PTE for (write) permission, since the CPU
901: * doesn't do it for us.
902: */
903:
904: /* Compute number of pages. */
905: movl %edi,%ecx
906: andl $PGOFSET,%ecx
907: addl %eax,%ecx
908: decl %ecx
909: shrl $PGSHIFT,%ecx
910:
911: /* Compute PTE offset for start address. */
912: shrl $PGSHIFT,%edi
913:
914: GET_CURPCB(%edx)
915: movl $2f,PCB_ONFAULT(%edx)
916:
917: 1: /* Check PTE for each page. */
918: testb $PG_RW,_C_LABEL(PTmap)(,%edi,4)
919: jz 2f
920:
921: 4: incl %edi
922: decl %ecx
923: jns 1b
924:
925: movl 20(%esp),%edi
926: movl 24(%esp),%eax
927: jmp 3f
928:
929: 2: /* Simulate a trap. */
930: pushl %ecx
931: movl %edi,%eax
932: shll $PGSHIFT,%eax
933: pushl %eax
934: call _C_LABEL(trapwrite) # trapwrite(addr)
935: addl $4,%esp # pop argument
936: popl %ecx
937: testl %eax,%eax # if not ok, return EFAULT
938: jz 4b
939: jmp _C_LABEL(copy_efault)
940:
941: 3: GET_CURPCB(%edx)
942: movl $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
943:
944: /* bcopy(%esi, %edi, %eax); */
945: cld
946: movl %eax,%ecx
947: shrl $2,%ecx
948: rep
949: movsl
950: movl %eax,%ecx
951: andl $3,%ecx
952: rep
953: movsb
954:
955: popl PCB_ONFAULT(%edx)
956: popl %edi
957: popl %esi
958: xorl %eax,%eax
959: ret
960: #endif /* I386_CPU */
961:
962: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
963: /* LINTSTUB: Func: int i486_copyout(const void *kaddr, void *uaddr, size_t len) */
964: ENTRY(i486_copyout)
965: pushl %esi
966: pushl %edi
967: pushl $0
968:
969: movl 16(%esp),%esi
970: movl 20(%esp),%edi
971: movl 24(%esp),%eax
972:
973: /*
974: * We check that the end of the destination buffer is not past the end
975: * of the user's address space.
976: */
977: movl %edi,%edx
978: addl %eax,%edx
979: jc _C_LABEL(copy_efault)
980: cmpl $VM_MAXUSER_ADDRESS,%edx
981: ja _C_LABEL(copy_efault)
982:
983: GET_CURPCB(%edx)
984: movl $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
985:
986: /* bcopy(%esi, %edi, %eax); */
987: cld
988: movl %eax,%ecx
989: shrl $2,%ecx
990: rep
991: movsl
992: movl %eax,%ecx
993: andl $3,%ecx
994: rep
995: movsb
996:
997: popl PCB_ONFAULT(%edx)
998: popl %edi
999: popl %esi
1000: xorl %eax,%eax
1001: ret
1002: #endif /* I486_CPU || I586_CPU || I686_CPU */
1003:
1004: /*
1005: * int copyin(const void *from, void *to, size_t len);
1006: * Copy len bytes from the user's address space.
1007: * see copyin(9)
1008: */
1009: /* LINTSTUB: Func: int copyin(const void *uaddr, void *kaddr, size_t len) */
1010: ENTRY(copyin)
1.24 yamt 1011: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1012: jmp *_C_LABEL(copyin_func)
1013:
1014: #if defined(I386_CPU) || defined(I486_CPU) || defined(I586_CPU) || \
1015: defined(I686_CPU)
1016: /* LINTSTUB: Func: int i386_copyin(const void *uaddr, void *kaddr, size_t len) */
1017: ENTRY(i386_copyin)
1018: pushl %esi
1019: pushl %edi
1020: GET_CURPCB(%eax)
1021: pushl $0
1022: movl $_C_LABEL(copy_fault),PCB_ONFAULT(%eax)
1023:
1024: movl 16(%esp),%esi
1025: movl 20(%esp),%edi
1026: movl 24(%esp),%eax
1027:
1028: /*
1029: * We check that the end of the destination buffer is not past the end
1030: * of the user's address space. If it's not, then we only need to
1031: * check that each page is readable, and the CPU will do that for us.
1032: */
1033: movl %esi,%edx
1034: addl %eax,%edx
1035: jc _C_LABEL(copy_efault)
1036: cmpl $VM_MAXUSER_ADDRESS,%edx
1037: ja _C_LABEL(copy_efault)
1038:
1039: /* bcopy(%esi, %edi, %eax); */
1040: cld
1041: movl %eax,%ecx
1042: shrl $2,%ecx
1043: rep
1044: movsl
1045: movl %eax,%ecx
1046: andl $3,%ecx
1047: rep
1048: movsb
1049:
1050: GET_CURPCB(%edx)
1051: popl PCB_ONFAULT(%edx)
1052: popl %edi
1053: popl %esi
1054: xorl %eax,%eax
1055: ret
1056: #endif /* I386_CPU || I486_CPU || I586_CPU || I686_CPU */
1057:
1058: /* LINTSTUB: Ignore */
1059: NENTRY(copy_efault)
1060: movl $EFAULT,%eax
1061:
1.24 yamt 1062: /*
1063: * kcopy_fault is used by kcopy and copy_fault is used by copyin/out.
1064: *
1065: * they're distinguished for lazy pmap switching. see trap().
1066: */
1067: /* LINTSTUB: Ignore */
1068: NENTRY(kcopy_fault)
1069: GET_CURPCB(%edx)
1070: popl PCB_ONFAULT(%edx)
1071: popl %edi
1072: popl %esi
1073: ret
1074:
1.1 fvdl 1075: /* LINTSTUB: Ignore */
1076: NENTRY(copy_fault)
1077: GET_CURPCB(%edx)
1078: popl PCB_ONFAULT(%edx)
1079: popl %edi
1080: popl %esi
1081: ret
1082:
1083: /*
1084: * int copyoutstr(const void *from, void *to, size_t maxlen, size_t *lencopied);
1085: * Copy a NUL-terminated string, at most maxlen characters long, into the
1086: * user's address space. Return the number of characters copied (including the
1087: * NUL) in *lencopied. If the string is too long, return ENAMETOOLONG; else
1088: * return 0 or EFAULT.
1089: * see copyoutstr(9)
1090: */
1091: /* LINTSTUB: Func: int copyoutstr(const void *kaddr, void *uaddr, size_t len, size_t *done) */
1092: ENTRY(copyoutstr)
1093: pushl %esi
1094: pushl %edi
1095:
1.24 yamt 1096: DO_DEFERRED_SWITCH(%eax)
1097:
1.1 fvdl 1098: movl 12(%esp),%esi # esi = from
1099: movl 16(%esp),%edi # edi = to
1100: movl 20(%esp),%edx # edx = maxlen
1101:
1102: #if defined(I386_CPU)
1103: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1104: cmpl $CPUCLASS_386,_C_LABEL(cpu_class)
1105: jne 5f
1106: #endif /* I486_CPU || I586_CPU || I686_CPU */
1107:
1108: /* Compute number of bytes in first page. */
1109: movl %edi,%eax
1110: andl $PGOFSET,%eax
1.7 thorpej 1111: movl $PAGE_SIZE,%ecx
1112: subl %eax,%ecx # ecx = PAGE_SIZE - (src % PAGE_SIZE)
1.1 fvdl 1113:
1114: GET_CURPCB(%eax)
1115: movl $6f,PCB_ONFAULT(%eax)
1116:
1117: 1: /*
1118: * Once per page, check that we are still within the bounds of user
1119: * space, and check for a write fault.
1120: */
1121: cmpl $VM_MAXUSER_ADDRESS,%edi
1122: jae _C_LABEL(copystr_efault)
1123:
1124: /* Compute PTE offset. */
1125: movl %edi,%eax
1126: shrl $PGSHIFT,%eax # calculate pte address
1127:
1128: testb $PG_RW,_C_LABEL(PTmap)(,%eax,4)
1129: jnz 2f
1130:
1131: 6: /* Simulate a trap. */
1132: pushl %edx
1133: pushl %edi
1134: call _C_LABEL(trapwrite) # trapwrite(addr)
1135: addl $4,%esp # clear argument from stack
1136: popl %edx
1137: testl %eax,%eax
1138: jnz _C_LABEL(copystr_efault)
1139:
1140: 2: /* Copy up to end of this page. */
1141: subl %ecx,%edx # predecrement total count
1142: jnc 3f
1143: addl %edx,%ecx # ecx += (edx - ecx) = edx
1144: xorl %edx,%edx
1145:
1146: 3: decl %ecx
1147: js 4f
1148: lodsb
1149: stosb
1150: testb %al,%al
1151: jnz 3b
1152:
1153: /* Success -- 0 byte reached. */
1154: addl %ecx,%edx # add back residual for this page
1155: xorl %eax,%eax
1156: jmp copystr_return
1157:
1158: 4: /* Go to next page, if any. */
1.7 thorpej 1159: movl $PAGE_SIZE,%ecx
1.1 fvdl 1160: testl %edx,%edx
1161: jnz 1b
1162:
1163: /* edx is zero -- return ENAMETOOLONG. */
1164: movl $ENAMETOOLONG,%eax
1165: jmp copystr_return
1166: #endif /* I386_CPU */
1167:
1168: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1169: 5: GET_CURPCB(%eax)
1170: movl $_C_LABEL(copystr_fault),PCB_ONFAULT(%eax)
1171: /*
1172: * Get min(%edx, VM_MAXUSER_ADDRESS-%edi).
1173: */
1174: movl $VM_MAXUSER_ADDRESS,%eax
1175: subl %edi,%eax
1176: cmpl %edx,%eax
1177: jae 1f
1178: movl %eax,%edx
1179: movl %eax,20(%esp)
1180:
1181: 1: incl %edx
1182: cld
1183:
1184: 1: decl %edx
1185: jz 2f
1186: lodsb
1187: stosb
1188: testb %al,%al
1189: jnz 1b
1190:
1191: /* Success -- 0 byte reached. */
1192: decl %edx
1193: xorl %eax,%eax
1194: jmp copystr_return
1195:
1196: 2: /* edx is zero -- return EFAULT or ENAMETOOLONG. */
1197: cmpl $VM_MAXUSER_ADDRESS,%edi
1198: jae _C_LABEL(copystr_efault)
1199: movl $ENAMETOOLONG,%eax
1200: jmp copystr_return
1201: #endif /* I486_CPU || I586_CPU || I686_CPU */
1202:
1203: /*
1204: * int copyinstr(const void *from, void *to, size_t maxlen, size_t *lencopied);
1205: * Copy a NUL-terminated string, at most maxlen characters long, from the
1206: * user's address space. Return the number of characters copied (including the
1207: * NUL) in *lencopied. If the string is too long, return ENAMETOOLONG; else
1208: * return 0 or EFAULT.
1209: * see copyinstr(9)
1210: */
1211: /* LINTSTUB: Func: int copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done) */
1212: ENTRY(copyinstr)
1213: pushl %esi
1214: pushl %edi
1.24 yamt 1215:
1216: DO_DEFERRED_SWITCH(%eax)
1217:
1.1 fvdl 1218: GET_CURPCB(%ecx)
1219: movl $_C_LABEL(copystr_fault),PCB_ONFAULT(%ecx)
1220:
1221: movl 12(%esp),%esi # %esi = from
1222: movl 16(%esp),%edi # %edi = to
1223: movl 20(%esp),%edx # %edx = maxlen
1224:
1225: /*
1226: * Get min(%edx, VM_MAXUSER_ADDRESS-%esi).
1227: */
1228: movl $VM_MAXUSER_ADDRESS,%eax
1229: subl %esi,%eax
1230: cmpl %edx,%eax
1231: jae 1f
1232: movl %eax,%edx
1233: movl %eax,20(%esp)
1234:
1235: 1: incl %edx
1236: cld
1237:
1238: 1: decl %edx
1239: jz 2f
1240: lodsb
1241: stosb
1242: testb %al,%al
1243: jnz 1b
1244:
1245: /* Success -- 0 byte reached. */
1246: decl %edx
1247: xorl %eax,%eax
1248: jmp copystr_return
1249:
1250: 2: /* edx is zero -- return EFAULT or ENAMETOOLONG. */
1251: cmpl $VM_MAXUSER_ADDRESS,%esi
1252: jae _C_LABEL(copystr_efault)
1253: movl $ENAMETOOLONG,%eax
1254: jmp copystr_return
1255:
1256: /* LINTSTUB: Ignore */
1257: NENTRY(copystr_efault)
1258: movl $EFAULT,%eax
1259:
1260: /* LINTSTUB: Ignore */
1261: NENTRY(copystr_fault)
1262: copystr_return:
1263: /* Set *lencopied and return %eax. */
1264: GET_CURPCB(%ecx)
1265: movl $0,PCB_ONFAULT(%ecx)
1266: movl 20(%esp),%ecx
1267: subl %edx,%ecx
1268: movl 24(%esp),%edx
1269: testl %edx,%edx
1270: jz 8f
1271: movl %ecx,(%edx)
1272:
1273: 8: popl %edi
1274: popl %esi
1275: ret
1276:
1277: /*
1278: * int copystr(const void *from, void *to, size_t maxlen, size_t *lencopied);
1279: * Copy a NUL-terminated string, at most maxlen characters long. Return the
1280: * number of characters copied (including the NUL) in *lencopied. If the
1281: * string is too long, return ENAMETOOLONG; else return 0.
1282: * see copystr(9)
1283: */
1284: /* LINTSTUB: Func: int copystr(const void *kfaddr, void *kdaddr, size_t len, size_t *done) */
1285: ENTRY(copystr)
1286: pushl %esi
1287: pushl %edi
1288:
1289: movl 12(%esp),%esi # esi = from
1290: movl 16(%esp),%edi # edi = to
1291: movl 20(%esp),%edx # edx = maxlen
1292: incl %edx
1293: cld
1294:
1295: 1: decl %edx
1296: jz 4f
1297: lodsb
1298: stosb
1299: testb %al,%al
1300: jnz 1b
1301:
1302: /* Success -- 0 byte reached. */
1303: decl %edx
1304: xorl %eax,%eax
1305: jmp 6f
1306:
1307: 4: /* edx is zero -- return ENAMETOOLONG. */
1308: movl $ENAMETOOLONG,%eax
1309:
1310: 6: /* Set *lencopied and return %eax. */
1311: movl 20(%esp),%ecx
1312: subl %edx,%ecx
1313: movl 24(%esp),%edx
1314: testl %edx,%edx
1315: jz 7f
1316: movl %ecx,(%edx)
1317:
1318: 7: popl %edi
1319: popl %esi
1320: ret
1321:
1322: /*
1323: * long fuword(const void *uaddr);
1324: * Fetch an int from the user's address space.
1325: * see fuword(9)
1326: */
1327: /* LINTSTUB: Func: long fuword(const void *base) */
1328: ENTRY(fuword)
1.24 yamt 1329: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1330: movl 4(%esp),%edx
1331: cmpl $VM_MAXUSER_ADDRESS-4,%edx
1332: ja _C_LABEL(fusuaddrfault)
1333: GET_CURPCB(%ecx)
1334: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1335: movl (%edx),%eax
1336: movl $0,PCB_ONFAULT(%ecx)
1337: ret
1338:
1339: /*
1340: * int fusword(const void *uaddr);
1341: * Fetch a short from the user's address space.
1342: * see fusword(9)
1343: */
1344: /* LINTSTUB: Func: int fusword(const void *base) */
1345: ENTRY(fusword)
1.24 yamt 1346: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1347: movl 4(%esp),%edx
1348: cmpl $VM_MAXUSER_ADDRESS-2,%edx
1349: ja _C_LABEL(fusuaddrfault)
1350: GET_CURPCB(%ecx)
1351: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1352: movzwl (%edx),%eax
1353: movl $0,PCB_ONFAULT(%ecx)
1354: ret
1355:
1356: /*
1357: * int fuswintr(const void *uaddr);
1358: * Fetch a short from the user's address space. Can be called during an
1359: * interrupt.
1360: * see fuswintr(9)
1361: */
1362: /* LINTSTUB: Func: int fuswintr(const void *base) */
1363: ENTRY(fuswintr)
1.24 yamt 1364: cmpl $TLBSTATE_VALID, CPUVAR(TLBSTATE)
1365: jnz _C_LABEL(fusuaddrfault)
1.1 fvdl 1366: movl 4(%esp),%edx
1367: cmpl $VM_MAXUSER_ADDRESS-2,%edx
1368: ja _C_LABEL(fusuaddrfault)
1.5 thorpej 1369: movl CPUVAR(CURLWP),%ecx
1370: movl L_ADDR(%ecx),%ecx
1.1 fvdl 1371: movl $_C_LABEL(fusubail),PCB_ONFAULT(%ecx)
1372: movzwl (%edx),%eax
1373: movl $0,PCB_ONFAULT(%ecx)
1374: ret
1375:
1376: /*
1377: * int fubyte(const void *uaddr);
1378: * Fetch a byte from the user's address space.
1379: * see fubyte(9)
1380: */
1381: /* LINTSTUB: Func: int fubyte(const void *base) */
1382: ENTRY(fubyte)
1.24 yamt 1383: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1384: movl 4(%esp),%edx
1385: cmpl $VM_MAXUSER_ADDRESS-1,%edx
1386: ja _C_LABEL(fusuaddrfault)
1387: GET_CURPCB(%ecx)
1388: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1389: movzbl (%edx),%eax
1390: movl $0,PCB_ONFAULT(%ecx)
1391: ret
1392:
1393: /*
1394: * Handle faults from [fs]u*(). Clean up and return -1.
1395: */
1396: /* LINTSTUB: Ignore */
1397: NENTRY(fusufault)
1398: movl $0,PCB_ONFAULT(%ecx)
1399: movl $-1,%eax
1400: ret
1401:
1402: /*
1403: * Handle faults from [fs]u*(). Clean up and return -1. This differs from
1404: * fusufault() in that trap() will recognize it and return immediately rather
1405: * than trying to page fault.
1406: */
1407: /* LINTSTUB: Ignore */
1408: NENTRY(fusubail)
1409: movl $0,PCB_ONFAULT(%ecx)
1410: movl $-1,%eax
1411: ret
1412:
1413: /*
1414: * Handle earlier faults from [fs]u*(), due to our of range addresses.
1415: */
1416: /* LINTSTUB: Ignore */
1417: NENTRY(fusuaddrfault)
1418: movl $-1,%eax
1419: ret
1420:
1421: /*
1422: * int suword(void *uaddr, long x);
1423: * Store an int in the user's address space.
1424: * see suword(9)
1425: */
1426: /* LINTSTUB: Func: int suword(void *base, long c) */
1427: ENTRY(suword)
1.24 yamt 1428: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1429: movl 4(%esp),%edx
1430: cmpl $VM_MAXUSER_ADDRESS-4,%edx
1431: ja _C_LABEL(fusuaddrfault)
1432:
1433: #if defined(I386_CPU)
1434: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1435: cmpl $CPUCLASS_386,_C_LABEL(cpu_class)
1436: jne 2f
1437: #endif /* I486_CPU || I586_CPU || I686_CPU */
1438:
1439: GET_CURPCB(%eax)
1440: movl $3f,PCB_ONFAULT(%eax)
1441:
1442: movl %edx,%eax
1443: shrl $PGSHIFT,%eax # calculate pte address
1444: testb $PG_RW,_C_LABEL(PTmap)(,%eax,4)
1445: jnz 1f
1446:
1447: 3: /* Simulate a trap. */
1448: pushl %edx
1449: pushl %edx
1450: call _C_LABEL(trapwrite) # trapwrite(addr)
1451: addl $4,%esp # clear parameter from the stack
1452: popl %edx
1453: GET_CURPCB(%ecx)
1454: testl %eax,%eax
1455: jnz _C_LABEL(fusufault)
1456:
1457: 1: /* XXX also need to check the following 3 bytes for validity! */
1458: #endif
1459:
1460: 2: GET_CURPCB(%ecx)
1461: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1462:
1463: movl 8(%esp),%eax
1464: movl %eax,(%edx)
1465: xorl %eax,%eax
1466: movl %eax,PCB_ONFAULT(%ecx)
1467: ret
1468:
1469: /*
1470: * int susword(void *uaddr, short x);
1471: * Store a short in the user's address space.
1472: * see susword(9)
1473: */
1474: /* LINTSTUB: Func: int susword(void *base, short c) */
1475: ENTRY(susword)
1.24 yamt 1476: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1477: movl 4(%esp),%edx
1478: cmpl $VM_MAXUSER_ADDRESS-2,%edx
1479: ja _C_LABEL(fusuaddrfault)
1480:
1481: #if defined(I386_CPU)
1482: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1483: cmpl $CPUCLASS_386,_C_LABEL(cpu_class)
1484: jne 2f
1485: #endif /* I486_CPU || I586_CPU || I686_CPU */
1486:
1487: GET_CURPCB(%eax)
1488: movl $3f,PCB_ONFAULT(%eax)
1489:
1490: movl %edx,%eax
1491: shrl $PGSHIFT,%eax # calculate pte address
1492: testb $PG_RW,_C_LABEL(PTmap)(,%eax,4)
1493: jnz 1f
1494:
1495: 3: /* Simulate a trap. */
1496: pushl %edx
1497: pushl %edx
1498: call _C_LABEL(trapwrite) # trapwrite(addr)
1499: addl $4,%esp # clear parameter from the stack
1500: popl %edx
1501: GET_CURPCB(%ecx)
1502: testl %eax,%eax
1503: jnz _C_LABEL(fusufault)
1504:
1505: 1: /* XXX also need to check the following byte for validity! */
1506: #endif
1507:
1508: 2: GET_CURPCB(%ecx)
1509: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1510:
1511: movl 8(%esp),%eax
1512: movw %ax,(%edx)
1513: xorl %eax,%eax
1514: movl %eax,PCB_ONFAULT(%ecx)
1515: ret
1516:
1517: /*
1518: * int suswintr(void *uaddr, short x);
1519: * Store a short in the user's address space. Can be called during an
1520: * interrupt.
1521: * see suswintr(9)
1522: */
1523: /* LINTSTUB: Func: int suswintr(void *base, short c) */
1524: ENTRY(suswintr)
1.24 yamt 1525: cmpl $TLBSTATE_VALID, CPUVAR(TLBSTATE)
1526: jnz _C_LABEL(fusuaddrfault)
1.1 fvdl 1527: movl 4(%esp),%edx
1528: cmpl $VM_MAXUSER_ADDRESS-2,%edx
1529: ja _C_LABEL(fusuaddrfault)
1.5 thorpej 1530: movl CPUVAR(CURLWP),%ecx
1531: movl L_ADDR(%ecx),%ecx
1.1 fvdl 1532: movl $_C_LABEL(fusubail),PCB_ONFAULT(%ecx)
1533:
1534: #if defined(I386_CPU)
1535: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1536: cmpl $CPUCLASS_386,_C_LABEL(cpu_class)
1537: jne 2f
1538: #endif /* I486_CPU || I586_CPU || I686_CPU */
1539:
1540: movl %edx,%eax
1541: shrl $PGSHIFT,%eax # calculate pte address
1542: testb $PG_RW,_C_LABEL(PTmap)(,%eax,4)
1543: jnz 1f
1544:
1545: /* Simulate a trap. */
1546: jmp _C_LABEL(fusubail)
1547:
1548: 1: /* XXX also need to check the following byte for validity! */
1549: #endif
1550:
1551: 2: movl 8(%esp),%eax
1552: movw %ax,(%edx)
1553: xorl %eax,%eax
1554: movl %eax,PCB_ONFAULT(%ecx)
1555: ret
1556:
1557: /*
1558: * int subyte(void *uaddr, char x);
1559: * Store a byte in the user's address space.
1560: * see subyte(9)
1561: */
1562: /* LINTSTUB: Func: int subyte(void *base, int c) */
1563: ENTRY(subyte)
1.24 yamt 1564: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 1565: movl 4(%esp),%edx
1566: cmpl $VM_MAXUSER_ADDRESS-1,%edx
1567: ja _C_LABEL(fusuaddrfault)
1568:
1569: #if defined(I386_CPU)
1570: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
1571: cmpl $CPUCLASS_386,_C_LABEL(cpu_class)
1572: jne 2f
1573: #endif /* I486_CPU || I586_CPU || I686_CPU */
1574:
1575: GET_CURPCB(%eax)
1576: movl $3f,PCB_ONFAULT(%eax)
1577:
1578: movl %edx,%eax
1579: shrl $PGSHIFT,%eax # calculate pte address
1580: testb $PG_RW,_C_LABEL(PTmap)(,%eax,4)
1581: jnz 1f
1582:
1583: 3: /* Simulate a trap. */
1584: pushl %edx
1585: pushl %edx
1586: call _C_LABEL(trapwrite) # trapwrite(addr)
1587: addl $4,%esp # clear parameter from the stack
1588: popl %edx
1589: GET_CURPCB(%ecx)
1590: testl %eax,%eax
1591: jnz _C_LABEL(fusufault)
1592:
1593: 1:
1594: #endif
1595:
1596: 2: GET_CURPCB(%ecx)
1597: movl $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
1598:
1599: movb 8(%esp),%al
1600: movb %al,(%edx)
1601: xorl %eax,%eax
1602: movl %eax,PCB_ONFAULT(%ecx)
1603: ret
1604:
1605: /*****************************************************************************/
1606:
1607: /*
1608: * The following is i386-specific nonsense.
1609: */
1610:
1611: /*
1612: * void lgdt(struct region_descriptor *rdp);
1613: * Load a new GDT pointer (and do any necessary cleanup).
1614: * XXX It's somewhat questionable whether reloading all the segment registers
1615: * is necessary, since the actual descriptor data is not changed except by
1616: * process creation and exit, both of which clean up via task switches. OTOH,
1617: * this only happens at run time when the GDT is resized.
1618: */
1619: /* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */
1620: NENTRY(lgdt)
1621: /* Reload the descriptor table. */
1622: movl 4(%esp),%eax
1623: lgdt (%eax)
1624: /* Flush the prefetch queue. */
1625: jmp 1f
1626: nop
1627: 1: /* Reload "stale" selectors. */
1628: movl $GSEL(GDATA_SEL, SEL_KPL),%eax
1629: movw %ax,%ds
1630: movw %ax,%es
1631: movw %ax,%gs
1632: movw %ax,%ss
1633: movl $GSEL(GCPU_SEL, SEL_KPL),%eax
1634: movw %ax,%fs
1635: /* Reload code selector by doing intersegment return. */
1636: popl %eax
1637: pushl $GSEL(GCODE_SEL, SEL_KPL)
1638: pushl %eax
1639: lret
1640:
1641: /*****************************************************************************/
1642:
1643: /*
1644: * These functions are primarily used by DDB.
1645: */
1646:
1647: /* LINTSTUB: Func: int setjmp (label_t *l) */
1648: ENTRY(setjmp)
1649: movl 4(%esp),%eax
1650: movl %ebx,(%eax) # save ebx
1651: movl %esp,4(%eax) # save esp
1652: movl %ebp,8(%eax) # save ebp
1653: movl %esi,12(%eax) # save esi
1654: movl %edi,16(%eax) # save edi
1655: movl (%esp),%edx # get rta
1656: movl %edx,20(%eax) # save eip
1657: xorl %eax,%eax # return (0);
1658: ret
1659:
1660: /* LINTSTUB: Func: void longjmp (label_t *l) */
1661: ENTRY(longjmp)
1662: movl 4(%esp),%eax
1663: movl (%eax),%ebx # restore ebx
1664: movl 4(%eax),%esp # restore esp
1665: movl 8(%eax),%ebp # restore ebp
1666: movl 12(%eax),%esi # restore esi
1667: movl 16(%eax),%edi # restore edi
1668: movl 20(%eax),%edx # get rta
1669: movl %edx,(%esp) # put in return frame
1670: xorl %eax,%eax # return (1);
1671: incl %eax
1672: ret
1673:
1674: /*****************************************************************************/
1675:
1676: .globl _C_LABEL(sched_whichqs),_C_LABEL(sched_qs)
1677: .globl _C_LABEL(uvmexp),_C_LABEL(panic)
1678:
1679: #ifdef DIAGNOSTIC
1680: NENTRY(switch_error)
1681: pushl $1f
1682: call _C_LABEL(panic)
1683: /* NOTREACHED */
1684: 1: .asciz "cpu_switch"
1685: #endif /* DIAGNOSTIC */
1686:
1687: /*
1.5 thorpej 1688: * void cpu_switch(struct lwp *)
1.1 fvdl 1689: * Find a runnable process and switch to it. Wait if necessary. If the new
1690: * process is the same as the old one, we short-circuit the context save and
1691: * restore.
1692: *
1693: * Note that the stack frame layout is known to "struct switchframe"
1694: * in <machine/frame.h> and to the code in cpu_fork() which initializes
1.5 thorpej 1695: * it for a new lwp.
1.1 fvdl 1696: */
1697: ENTRY(cpu_switch)
1698: pushl %ebx
1699: pushl %esi
1700: pushl %edi
1701:
1702: #ifdef DEBUG
1703: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
1704: jae 1f
1.5 thorpej 1705: pushl $2f
1.1 fvdl 1706: call _C_LABEL(panic)
1707: /* NOTREACHED */
1.5 thorpej 1708: 2: .asciz "not splsched() in cpu_switch!"
1.1 fvdl 1709: 1:
1710: #endif /* DEBUG */
1711:
1.5 thorpej 1712: movl 16(%esp),%esi # current
1.1 fvdl 1713:
1714: /*
1.5 thorpej 1715: * Clear curlwp so that we don't accumulate system time while idle.
1716: * This also insures that schedcpu() will move the old lwp to
1.1 fvdl 1717: * the correct queue if it happens to get called from the spllower()
1718: * below and changes the priority. (See corresponding comment in
1719: * userret()).
1720: */
1.5 thorpej 1721: movl $0,CPUVAR(CURLWP)
1.1 fvdl 1722: /*
1.5 thorpej 1723: * First phase: find new lwp.
1.1 fvdl 1724: *
1725: * Registers:
1726: * %eax - queue head, scratch, then zero
1727: * %ebx - queue number
1728: * %ecx - cached value of whichqs
1.5 thorpej 1729: * %edx - next lwp in queue
1730: * %esi - old lwp
1731: * %edi - new lwp
1.1 fvdl 1732: */
1733:
1.5 thorpej 1734: /* Look for new lwp. */
1.1 fvdl 1735: cli # splhigh doesn't do a cli
1736: movl _C_LABEL(sched_whichqs),%ecx
1737: bsfl %ecx,%ebx # find a full q
1738: jnz switch_dequeue
1739:
1740: /*
1741: * idling: save old context.
1742: *
1743: * Registers:
1744: * %eax, %ecx - scratch
1.5 thorpej 1745: * %esi - old lwp, then old pcb
1.1 fvdl 1746: * %edi - idle pcb
1747: */
1748:
1749: pushl %esi
1.24 yamt 1750: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 1751: addl $4,%esp
1752:
1.5 thorpej 1753: movl L_ADDR(%esi),%esi
1.1 fvdl 1754:
1755: /* Save stack pointers. */
1756: movl %esp,PCB_ESP(%esi)
1757: movl %ebp,PCB_EBP(%esi)
1758:
1759: /* Find idle PCB for this CPU */
1760: #ifndef MULTIPROCESSOR
1.5 thorpej 1761: movl $_C_LABEL(lwp0),%ebx
1762: movl L_ADDR(%ebx),%edi
1763: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 1764: #else
1765: movl CPUVAR(IDLE_PCB),%edi
1766: movl CPUVAR(IDLE_TSS_SEL),%edx
1767: #endif
1.5 thorpej 1768: movl $0,CPUVAR(CURLWP) /* In case we fault... */
1.1 fvdl 1769:
1770: /* Restore the idle context (avoid interrupts) */
1771: cli
1772:
1773: /* Restore stack pointers. */
1774: movl PCB_ESP(%edi),%esp
1775: movl PCB_EBP(%edi),%ebp
1776:
1777: /* Switch TSS. Reset "task busy" flag before loading. */
1778: #ifdef MULTIPROCESSOR
1779: movl CPUVAR(GDT),%eax
1780: #else
1781: movl _C_LABEL(gdt),%eax
1782: #endif
1783: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
1784: ltr %dx
1785:
1786: /* We're always in the kernel, so we don't need the LDT. */
1787:
1788: /* Restore cr0 (including FPU state). */
1789: movl PCB_CR0(%edi),%ecx
1790: movl %ecx,%cr0
1791:
1792: /* Record new pcb. */
1793: SET_CURPCB(%edi)
1794:
1795: xorl %esi,%esi
1796: sti
1797: idle_unlock:
1798: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1799: call _C_LABEL(sched_unlock_idle)
1800: #endif
1801: /* Interrupts are okay again. */
1.2 fvdl 1802: pushl $IPL_NONE # spl0()
1.1 fvdl 1803: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 1804: addl $4,%esp
1.1 fvdl 1805: jmp idle_start
1806: idle_zero:
1807: sti
1808: call _C_LABEL(uvm_pageidlezero)
1809: cli
1810: cmpl $0,_C_LABEL(sched_whichqs)
1811: jnz idle_exit
1812: idle_loop:
1813: /* Try to zero some pages. */
1814: movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
1815: testl %ecx,%ecx
1816: jnz idle_zero
1817: sti
1818: hlt
1819: NENTRY(mpidle)
1820: idle_start:
1821: cli
1822: cmpl $0,_C_LABEL(sched_whichqs)
1823: jz idle_loop
1824: idle_exit:
1825: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh
1.14 fvdl 1826: sti
1.1 fvdl 1827: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1828: call _C_LABEL(sched_lock_idle)
1829: #endif
1830: movl _C_LABEL(sched_whichqs),%ecx
1831: bsfl %ecx,%ebx
1832: jz idle_unlock
1833:
1834: switch_dequeue:
1835: /*
1836: * we're running at splhigh(), but it's otherwise okay to take
1837: * interrupts here.
1838: */
1839: sti
1840: leal _C_LABEL(sched_qs)(,%ebx,8),%eax # select q
1841:
1.5 thorpej 1842: movl L_FORW(%eax),%edi # unlink from front of process q
1.1 fvdl 1843: #ifdef DIAGNOSTIC
1844: cmpl %edi,%eax # linked to self (i.e. nothing queued)?
1845: je _C_LABEL(switch_error) # not possible
1846: #endif /* DIAGNOSTIC */
1.5 thorpej 1847: movl L_FORW(%edi),%edx
1848: movl %edx,L_FORW(%eax)
1849: movl %eax,L_BACK(%edx)
1.1 fvdl 1850:
1851: cmpl %edx,%eax # q empty?
1852: jne 3f
1853:
1854: btrl %ebx,%ecx # yes, clear to indicate empty
1855: movl %ecx,_C_LABEL(sched_whichqs) # update q status
1856:
1857: 3: /* We just did it. */
1858: xorl %eax,%eax
1859: CLEAR_RESCHED(%eax)
1860:
1.5 thorpej 1861: switch_resume:
1.1 fvdl 1862: #ifdef DIAGNOSTIC
1.5 thorpej 1863: cmpl %eax,L_WCHAN(%edi) # Waiting for something?
1.1 fvdl 1864: jne _C_LABEL(switch_error) # Yes; shouldn't be queued.
1.5 thorpej 1865: cmpb $LSRUN,L_STAT(%edi) # In run state?
1.1 fvdl 1866: jne _C_LABEL(switch_error) # No; shouldn't be queued.
1867: #endif /* DIAGNOSTIC */
1868:
1.5 thorpej 1869: /* Isolate lwp. XXX Is this necessary? */
1870: movl %eax,L_BACK(%edi)
1.1 fvdl 1871:
1.5 thorpej 1872: /* Record new lwp. */
1873: movb $LSONPROC,L_STAT(%edi) # l->l_stat = LSONPROC
1874: SET_CURLWP(%edi,%ecx)
1.1 fvdl 1875:
1.5 thorpej 1876: /* Skip context switch if same lwp. */
1.10 fvdl 1877: xorl %ebx,%ebx
1.1 fvdl 1878: cmpl %edi,%esi
1879: je switch_return
1880:
1.5 thorpej 1881: /* If old lwp exited, don't bother. */
1.1 fvdl 1882: testl %esi,%esi
1883: jz switch_exited
1884:
1885: /*
1886: * Second phase: save old context.
1887: *
1888: * Registers:
1889: * %eax, %ecx - scratch
1.5 thorpej 1890: * %esi - old lwp, then old pcb
1891: * %edi - new lwp
1.1 fvdl 1892: */
1893:
1894: pushl %esi
1.24 yamt 1895: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 1896: addl $4,%esp
1897:
1.5 thorpej 1898: movl L_ADDR(%esi),%esi
1.1 fvdl 1899:
1900: /* Save stack pointers. */
1901: movl %esp,PCB_ESP(%esi)
1902: movl %ebp,PCB_EBP(%esi)
1903:
1904: switch_exited:
1905: /*
1906: * Third phase: restore saved context.
1907: *
1908: * Registers:
1909: * %eax, %ebx, %ecx, %edx - scratch
1910: * %esi - new pcb
1.5 thorpej 1911: * %edi - new lwp
1.1 fvdl 1912: */
1913:
1914: /* No interrupts while loading new state. */
1915: cli
1.5 thorpej 1916: movl L_ADDR(%edi),%esi
1.1 fvdl 1917:
1918: /* Restore stack pointers. */
1919: movl PCB_ESP(%esi),%esp
1920: movl PCB_EBP(%esi),%ebp
1921:
1922: #if 0
1923: /* Don't bother with the rest if switching to a system process. */
1.5 thorpej 1924: testl $P_SYSTEM,L_FLAG(%edi); XXX NJWLWP lwp's don't have P_SYSTEM!
1.1 fvdl 1925: jnz switch_restored
1926: #endif
1927:
1928: #ifdef MULTIPROCESSOR
1929: movl CPUVAR(GDT),%eax
1930: #else
1931: /* Load TSS info. */
1932: movl _C_LABEL(gdt),%eax
1933: #endif
1.5 thorpej 1934: movl L_MD_TSS_SEL(%edi),%edx
1.1 fvdl 1935:
1936: /* Switch TSS. Reset "task busy" flag before loading. */
1937: andl $~0x0200,4(%eax,%edx, 1)
1938: ltr %dx
1939:
1940: pushl %edi
1941: call _C_LABEL(pmap_activate) # pmap_activate(p)
1942: addl $4,%esp
1943:
1944: #if 0
1945: switch_restored:
1946: #endif
1947: /* Restore cr0 (including FPU state). */
1948: movl PCB_CR0(%esi),%ecx
1949: #ifdef MULTIPROCESSOR
1950: /*
1.22 wiz 1951: * If our floating point registers are on a different CPU,
1.1 fvdl 1952: * clear CR0_TS so we'll trap rather than reuse bogus state.
1953: */
1954: movl PCB_FPCPU(%esi),%ebx
1955: cmpl CPUVAR(SELF),%ebx
1956: jz 1f
1957: orl $CR0_TS,%ecx
1958: 1:
1959: #endif
1960: movl %ecx,%cr0
1961:
1962: /* Record new pcb. */
1963: SET_CURPCB(%esi)
1964:
1965: /* Interrupts are okay again. */
1966: sti
1967:
1968: /*
1969: * Check for restartable atomic sequences (RAS)
1970: */
1.5 thorpej 1971: movl CPUVAR(CURLWP),%edi
1972: movl L_PROC(%edi),%esi
1.20 dsl 1973: cmpl $0,P_RASLIST(%esi)
1974: jne 2f
1.1 fvdl 1975: 1:
1.10 fvdl 1976: movl $1,%ebx
1.1 fvdl 1977:
1978: switch_return:
1979: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1980: call _C_LABEL(sched_unlock_idle)
1981: #endif
1.2 fvdl 1982: pushl $IPL_NONE # spl0()
1.1 fvdl 1983: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 1984: addl $4,%esp
1.1 fvdl 1985: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh()
1.9 fvdl 1986:
1987: movl %ebx,%eax
1.1 fvdl 1988:
1989: popl %edi
1990: popl %esi
1991: popl %ebx
1992: ret
1.20 dsl 1993:
1994: 2: # check RAS list
1995: movl L_MD_REGS(%edi),%ebx
1996: movl TF_EIP(%ebx),%eax
1997: pushl %eax
1998: pushl %esi
1999: call _C_LABEL(ras_lookup)
2000: addl $8,%esp
2001: cmpl $-1,%eax
2002: je 1b
2003: movl %eax,TF_EIP(%ebx)
2004: jmp 1b
1.1 fvdl 2005:
2006: /*
1.5 thorpej 2007: * void cpu_switchto(struct lwp *current, struct lwp *next)
2008: * Switch to the specified next LWP.
2009: */
2010: ENTRY(cpu_switchto)
2011: pushl %ebx
2012: pushl %esi
2013: pushl %edi
2014:
2015: #ifdef DEBUG
2016: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
2017: jae 1f
2018: pushl $2f
2019: call _C_LABEL(panic)
2020: /* NOTREACHED */
2021: 2: .asciz "not splsched() in cpu_switchto!"
2022: 1:
2023: #endif /* DEBUG */
2024:
2025: movl 16(%esp),%esi # current
2026: movl 20(%esp),%edi # next
2027:
2028: /*
2029: * Clear curlwp so that we don't accumulate system time while idle.
2030: * This also insures that schedcpu() will move the old process to
2031: * the correct queue if it happens to get called from the spllower()
2032: * below and changes the priority. (See corresponding comment in
2033: * usrret()).
2034: *
2035: * XXX Is this necessary? We know we won't go idle.
2036: */
2037: movl $0,CPUVAR(CURLWP)
2038:
2039: /*
2040: * We're running at splhigh(), but it's otherwise okay to take
2041: * interrupts here.
2042: */
2043: sti
2044:
2045: /* Jump into the middle of cpu_switch */
2046: xorl %eax,%eax
2047: jmp switch_resume
2048:
2049: /*
1.21 jdolecek 2050: * void cpu_exit(struct lwp *l)
1.22 wiz 2051: * Switch to the appropriate idle context (lwp0's if uniprocessor; the CPU's
1.1 fvdl 2052: * if multiprocessor) and deallocate the address space and kernel stack for p.
2053: * Then jump into cpu_switch(), as if we were in the idle proc all along.
2054: */
2055: #ifndef MULTIPROCESSOR
1.5 thorpej 2056: .globl _C_LABEL(lwp0)
1.1 fvdl 2057: #endif
2058: .globl _C_LABEL(uvmspace_free),_C_LABEL(kernel_map)
2059: .globl _C_LABEL(uvm_km_free),_C_LABEL(tss_free)
1.21 jdolecek 2060: /* LINTSTUB: Func: void cpu_exit(struct lwp *l) */
2061: ENTRY(cpu_exit)
1.1 fvdl 2062: movl 4(%esp),%edi # old process
2063: #ifndef MULTIPROCESSOR
1.5 thorpej 2064: movl $_C_LABEL(lwp0),%ebx
2065: movl L_ADDR(%ebx),%esi
2066: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 2067: #else
2068: movl CPUVAR(IDLE_PCB),%esi
2069: movl CPUVAR(IDLE_TSS_SEL),%edx
2070: #endif
2071: /* In case we fault... */
1.5 thorpej 2072: movl $0,CPUVAR(CURLWP)
1.1 fvdl 2073:
2074: /* Restore the idle context. */
2075: cli
2076:
2077: /* Restore stack pointers. */
2078: movl PCB_ESP(%esi),%esp
2079: movl PCB_EBP(%esi),%ebp
2080:
2081: /* Load TSS info. */
2082: #ifdef MULTIPROCESSOR
2083: movl CPUVAR(GDT),%eax
2084: #else
2085: /* Load TSS info. */
2086: movl _C_LABEL(gdt),%eax
2087: #endif
2088:
2089: /* Switch TSS. */
2090: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
2091: ltr %dx
2092:
2093: /* We're always in the kernel, so we don't need the LDT. */
2094:
2095: /* Restore cr0 (including FPU state). */
2096: movl PCB_CR0(%esi),%ecx
2097: movl %ecx,%cr0
2098:
2099: /* Record new pcb. */
2100: SET_CURPCB(%esi)
2101:
2102: /* Interrupts are okay again. */
2103: sti
2104:
2105: /*
1.21 jdolecek 2106: * Schedule the dead LWP's stack to be freed.
1.1 fvdl 2107: */
1.21 jdolecek 2108: pushl %edi
2109: call _C_LABEL(lwp_exit2)
1.1 fvdl 2110: addl $4,%esp
2111:
2112: /* Jump into cpu_switch() with the right state. */
2113: xorl %esi,%esi
1.5 thorpej 2114: movl %esi,CPUVAR(CURLWP)
1.1 fvdl 2115: jmp idle_start
2116:
2117: /*
2118: * void savectx(struct pcb *pcb);
2119: * Update pcb, saving current processor state.
2120: */
2121: /* LINTSTUB: Func: void savectx(struct pcb *pcb) */
2122: ENTRY(savectx)
2123: movl 4(%esp),%edx # edx = p->p_addr
2124:
2125: /* Save stack pointers. */
2126: movl %esp,PCB_ESP(%edx)
2127: movl %ebp,PCB_EBP(%edx)
2128:
2129: ret
2130:
2131: /*
2132: * Old call gate entry for syscall
2133: */
2134: /* LINTSTUB: Var: char Xosyscall[1]; */
2135: IDTVEC(osyscall)
2136: /* Set eflags in trap frame. */
2137: pushfl
2138: popl 8(%esp)
2139: pushl $7 # size of instruction for restart
2140: jmp syscall1
2141:
2142: /*
2143: * Trap gate entry for syscall
2144: */
2145: /* LINTSTUB: Var: char Xsyscall[1]; */
2146: IDTVEC(syscall)
2147: pushl $2 # size of instruction for restart
2148: syscall1:
2149: pushl $T_ASTFLT # trap # for doing ASTs
2150: INTRENTRY
2151:
2152: #ifdef DIAGNOSTIC
1.24 yamt 2153: cmpl $0, CPUVAR(WANT_PMAPLOAD)
2154: jz 1f
2155: pushl $6f
2156: call _C_LABEL(printf)
2157: addl $4, %esp
2158: 1:
1.1 fvdl 2159: movl CPUVAR(ILEVEL),%ebx
2160: testl %ebx,%ebx
2161: jz 1f
2162: pushl $5f
2163: call _C_LABEL(printf)
2164: addl $4,%esp
2165: #ifdef DDB
2166: int $3
2167: #endif
2168: 1:
2169: #endif /* DIAGNOSTIC */
1.5 thorpej 2170: movl CPUVAR(CURLWP),%edx
2171: movl %esp,L_MD_REGS(%edx) # save pointer to frame
2172: movl L_PROC(%edx),%edx
1.15 fvdl 2173: pushl %esp
1.1 fvdl 2174: call *P_MD_SYSCALL(%edx) # get pointer to syscall() function
1.15 fvdl 2175: addl $4,%esp
1.24 yamt 2176: syscall_checkast:
2177: /* Check for ASTs on exit to user mode. */
1.1 fvdl 2178: cli
1.5 thorpej 2179: CHECK_ASTPENDING(%eax)
1.1 fvdl 2180: je 1f
2181: /* Always returning to user mode here. */
1.5 thorpej 2182: CLEAR_ASTPENDING(%eax)
1.1 fvdl 2183: sti
2184: /* Pushed T_ASTFLT into tf_trapno on entry. */
1.15 fvdl 2185: pushl %esp
1.1 fvdl 2186: call _C_LABEL(trap)
1.15 fvdl 2187: addl $4,%esp
1.24 yamt 2188: jmp syscall_checkast /* re-check ASTs */
2189: 1: CHECK_DEFERRED_SWITCH(%eax)
2190: jnz 9f
1.1 fvdl 2191: #ifndef DIAGNOSTIC
1.24 yamt 2192: INTRFASTEXIT
1.1 fvdl 2193: #else /* DIAGNOSTIC */
1.24 yamt 2194: cmpl $IPL_NONE,CPUVAR(ILEVEL)
1.1 fvdl 2195: jne 3f
2196: INTRFASTEXIT
2197: 3: sti
2198: pushl $4f
2199: call _C_LABEL(printf)
2200: addl $4,%esp
2201: #ifdef DDB
2202: int $3
2203: #endif /* DDB */
2204: movl $IPL_NONE,CPUVAR(ILEVEL)
2205: jmp 2b
2206: 4: .asciz "WARNING: SPL NOT LOWERED ON SYSCALL EXIT\n"
2207: 5: .asciz "WARNING: SPL NOT ZERO ON SYSCALL ENTRY\n"
1.24 yamt 2208: 6: .asciz "WARNING: WANT PMAPLOAD ON SYSCALL ENTRY\n"
1.1 fvdl 2209: #endif /* DIAGNOSTIC */
1.24 yamt 2210: 9: sti
2211: call _C_LABEL(pmap_load)
2212: jmp syscall_checkast /* re-check ASTs */
1.1 fvdl 2213:
2214: #if NNPX > 0
2215: /*
2216: * Special interrupt handlers. Someday intr0-intr15 will be used to count
2217: * interrupts. We'll still need a special exception 16 handler. The busy
2218: * latch stuff in probintr() can be moved to npxprobe().
2219: */
2220:
2221: /* LINTSTUB: Func: void probeintr(void) */
2222: NENTRY(probeintr)
2223: ss
2224: incl _C_LABEL(npx_intrs_while_probing)
2225: pushl %eax
2226: movb $0x20,%al # EOI (asm in strings loses cpp features)
2227: outb %al,$0xa0 # IO_ICU2
2228: outb %al,$0x20 # IO_ICU1
2229: movb $0,%al
2230: outb %al,$0xf0 # clear BUSY# latch
2231: popl %eax
2232: iret
2233:
2234: /* LINTSTUB: Func: void probetrap(void) */
2235: NENTRY(probetrap)
2236: ss
2237: incl _C_LABEL(npx_traps_while_probing)
2238: fnclex
2239: iret
2240:
2241: /* LINTSTUB: Func: int npx586bug1(int a, int b) */
2242: NENTRY(npx586bug1)
2243: fildl 4(%esp) # x
2244: fildl 8(%esp) # y
2245: fld %st(1)
2246: fdiv %st(1),%st # x/y
2247: fmulp %st,%st(1) # (x/y)*y
2248: fsubrp %st,%st(1) # x-(x/y)*y
2249: pushl $0
2250: fistpl (%esp)
2251: popl %eax
2252: ret
2253: #endif /* NNPX > 0 */
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