summaryrefslogtreecommitdiff
path: root/i386/i386at/model_dep.c
blob: f3a210df2f730c406e37532ac961288acca2019d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
/*
 * Mach Operating System
 * Copyright (c) 1991,1990,1989, 1988 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 *	File:	model_dep.c
 *	Author:	Avadis Tevanian, Jr., Michael Wayne Young
 *
 *	Copyright (C) 1986, Avadis Tevanian, Jr., Michael Wayne Young
 *
 *	Basic initialization for I386 - ISA bus machines.
 */

#include <platforms.h>
#include <mach_kdb.h>

#include <mach/vm_param.h>
#include <mach/vm_prot.h>
#include <mach/machine.h>
#include <mach/machine/multiboot.h>

#include "vm_param.h"
#include <kern/time_out.h>
#include <kern/assert.h>
#include <kern/cpu_number.h>
#include <sys/time.h>
#include <vm/vm_page.h>
#include <i386/machspl.h>
#include <i386/pmap.h>
#include "proc_reg.h"

/* Location of the kernel's symbol table.
   Both of these are 0 if none is available.  */
#if MACH_KDB
static vm_offset_t kern_sym_start, kern_sym_end;
#else
#define kern_sym_start	0
#define kern_sym_end	0
#endif

/* These indicate the total extent of physical memory addresses we're using.
   They are page-aligned.  */
vm_offset_t phys_first_addr = 0;
vm_offset_t phys_last_addr;

/* Virtual address of physical memory, for the kvtophys/phystokv macros.  */
vm_offset_t phys_mem_va;

/* A copy of the multiboot info structure passed by the boot loader.  */
struct multiboot_info boot_info;

/* Command line supplied to kernel.  */
char *kernel_cmdline = "";

/* This is used for memory initialization:
   it gets bumped up through physical memory
   that exists and is not occupied by boot gunk.
   It is not necessarily page-aligned.  */
static vm_offset_t avail_next = 0x1000; /* XX end of BIOS data area */

/* Possibly overestimated amount of available memory
   still remaining to be handed to the VM system.  */
static vm_size_t avail_remaining;

/* Configuration parameter:
   if zero, only use physical memory in the low 16MB of addresses.
   Only SCSI still has DMA problems.  */
#ifdef LINUX_DEV
#define use_all_mem 1
#else
#include "nscsi.h"
#if	NSCSI > 0
#define use_all_mem 0
#else
#define use_all_mem 1
#endif
#endif

extern char	version[];

extern void	setup_main();

void		halt_all_cpu (boolean_t reboot) __attribute__ ((noreturn));
void		halt_cpu (void) __attribute__ ((noreturn));

void		inittodr();	/* forward */

int		rebootflag = 0;	/* exported to kdintr */

/* XX interrupt stack pointer and highwater mark, for locore.S.  */
vm_offset_t int_stack_top, int_stack_high;

#ifdef LINUX_DEV
extern void linux_init(void);
#endif

/*
 * Find devices.  The system is alive.
 */
void machine_init()
{
	/*
	 * Initialize the console.
	 */
	cninit();

	/*
	 * Set up to use floating point.
	 */
	init_fpu();

#ifdef LINUX_DEV
	/*
	 * Initialize Linux drivers.
	 */
	linux_init();
#endif

	/*
	 * Find the devices
	 */
	probeio();

	/*
	 * Get the time
	 */
	inittodr();

	/*
	 * Tell the BIOS not to clear and test memory.
	 */
	*(unsigned short *)phystokv(0x472) = 0x1234;

	/*
	 * Unmap page 0 to trap NULL references.
	 */
	pmap_unmap_page_zero();
}

/* Conserve power on processor CPU.  */
void machine_idle (int cpu)
{
  assert (cpu == cpu_number ());
  asm volatile ("hlt" : : : "memory");
}

/*
 * Halt a cpu.
 */
void halt_cpu(void)
{
	asm volatile("cli");
	while(1);
}

/*
 * Halt the system or reboot.
 */
void halt_all_cpus(reboot)
	boolean_t	reboot;
{
	if (reboot) {
	    kdreboot();
	}
	else {
	    rebootflag = 1;
	    printf("In tight loop: hit ctl-alt-del to reboot\n");
	    (void) spl0();
	}
	for (;;)
	    continue;
}

void exit(int rc)
{
	halt_all_cpus(0);
}

void db_reset_cpu()
{
	halt_all_cpus(1);
}


/*
 * Compute physical memory size and other parameters.
 */
void
mem_size_init()
{
	/* Physical memory on all PCs starts at physical address 0.
	   XX make it a constant.  */
	phys_first_addr = 0;

	phys_last_addr = 0x100000 + (boot_info.mem_upper * 0x400);
	avail_remaining
	  = phys_last_addr - (0x100000 - (boot_info.mem_lower * 0x400)
			      - 0x1000);

	printf("AT386 boot: physical memory from 0x%x to 0x%x\n",
	       phys_first_addr, phys_last_addr);

	if ((!use_all_mem) && phys_last_addr > 16 * 1024*1024) {
		printf("** Limiting useable memory to 16 Meg to avoid DMA problems.\n");
		/* This is actually enforced below, in init_alloc_aligned.  */
	}

	phys_first_addr = round_page(phys_first_addr);
	phys_last_addr = trunc_page(phys_last_addr);
}

/*
 * Basic PC VM initialization.
 * Turns on paging and changes the kernel segments to use high linear addresses.
 */
i386at_init()
{
	/* XXX move to intel/pmap.h */
	extern pt_entry_t *kernel_page_dir;

	/*
	 * Initialize the PIC prior to any possible call to an spl.
	 */
	picinit();

	/*
	 * Find memory size parameters.
	 */
	mem_size_init();

	/*
	 *	Initialize kernel physical map, mapping the
	 *	region from loadpt to avail_start.
	 *	Kernel virtual address starts at VM_KERNEL_MIN_ADDRESS.
	 *	XXX make the BIOS page (page 0) read-only.
	 */
	pmap_bootstrap();

	/*
	 * Turn paging on.
	 * We'll have to temporarily install a direct mapping
	 * between physical memory and low linear memory,
	 * until we start using our new kernel segment descriptors.
	 * One page table (4MB) should do the trick.
	 * Also, set the WP bit so that on 486 or better processors
	 * page-level write protection works in kernel mode.
	 */
	kernel_page_dir[lin2pdenum(0)] =
		kernel_page_dir[lin2pdenum(LINEAR_MIN_KERNEL_ADDRESS)];
	set_cr3((unsigned)kernel_page_dir);
	set_cr0(get_cr0() | CR0_PG | CR0_WP);
	flush_instr_queue();

	/*
	 * Initialize and activate the real i386 protected-mode structures.
	 */
	gdt_init();
	idt_init();
	int_init();
	ldt_init();
	ktss_init();

	/* Get rid of the temporary direct mapping and flush it out of the TLB.  */
	kernel_page_dir[lin2pdenum(0)] = 0;
	set_cr3((unsigned)kernel_page_dir);



	/* XXX We'll just use the initialization stack we're already running on
	   as the interrupt stack for now.  Later this will have to change,
	   because the init stack will get freed after bootup.  */
	asm("movl %%esp,%0" : "=m" (int_stack_top));

	/* Interrupt stacks are allocated in physical memory,
	   while kernel stacks are allocated in kernel virtual memory,
	   so phys_last_addr serves as a convenient dividing point.  */
	int_stack_high = phys_last_addr;
}

/*
 *	C boot entrypoint - called by boot_entry in boothdr.S.
 *	Running in 32-bit flat mode, but without paging yet.
 */
void c_boot_entry(vm_offset_t bi)
{
	/* Stash the boot_image_info pointer.  */
	boot_info = *(struct multiboot_info*)phystokv(bi);

	/* XXX we currently assume phys_mem_va is always 0 here -
	   if it isn't, we must tweak the pointers in the boot_info.  */

	/* Before we do _anything_ else, print the hello message.
	   If there are no initialized console devices yet,
	   it will be stored and printed at the first opportunity.  */
	printf(version);
	printf("\n");

	/* Find the kernel command line, if there is one.  */
	if (boot_info.flags & MULTIBOOT_CMDLINE)
		kernel_cmdline = (char*)phystokv(boot_info.cmdline);

#if	MACH_KDB
	/*
	 * Locate the kernel's symbol table, if the boot loader provided it.
	 * We need to do this before i386at_init()
	 * so that the symbol table's memory won't be stomped on.
	 */
	if ((boot_info.flags & MULTIBOOT_AOUT_SYMS)
	    && boot_info.syms.a.addr)
	{
		vm_size_t symtab_size, strtab_size;

		kern_sym_start = (vm_offset_t)phystokv(boot_info.syms.a.addr);
		symtab_size = (vm_offset_t)phystokv(boot_info.syms.a.tabsize);
		strtab_size = (vm_offset_t)phystokv(boot_info.syms.a.strsize);
		kern_sym_end = kern_sym_start + 4 + symtab_size + strtab_size;

		printf("kernel symbol table at %08x-%08x (%d,%d)\n",
		       kern_sym_start, kern_sym_end,
		       symtab_size, strtab_size);
	}
#endif	/* MACH_KDB */

	/*
	 * Do basic VM initialization
	 */
	i386at_init();

#if	MACH_KDB
	/*
	 * Initialize the kernel debugger's kernel symbol table.
	 */
	if (kern_sym_start)
	{
		aout_db_sym_init(kern_sym_start, kern_sym_end, "mach", 0);
	}

	/*
	 * Cause a breakpoint trap to the debugger before proceeding
	 * any further if the proper option flag was specified
	 * on the kernel's command line.
	 * XXX check for surrounding spaces.
	 */
	if (strstr(kernel_cmdline, "-d ")) {
		cninit();		/* need console for debugger */
		Debugger();
	}
#endif	/* MACH_KDB */

	machine_slot[0].is_cpu = TRUE;
	machine_slot[0].running = TRUE;
	machine_slot[0].cpu_subtype = CPU_SUBTYPE_AT386;

	switch (discover_x86_cpu_type ())
	  {
	  case 3:
	  default:
	    machine_slot[0].cpu_type = CPU_TYPE_I386;
	    break;
	  case 4:
	    machine_slot[0].cpu_type = CPU_TYPE_I486;
	    break;
	  case 5:
	    machine_slot[0].cpu_type = CPU_TYPE_PENTIUM;
	    break;
	  case 6:
	    machine_slot[0].cpu_type = CPU_TYPE_PENTIUMPRO;
	    break;
	  }

	/*
	 * Start the system.
	 */
	setup_main();

}

#include <mach/vm_prot.h>
#include <vm/pmap.h>
#include <mach/time_value.h>

timemmap(dev,off,prot)
	vm_prot_t prot;
{
	extern time_value_t *mtime;

#ifdef	lint
	dev++; off++;
#endif	/* lint */

	if (prot & VM_PROT_WRITE) return (-1);

	return (i386_btop(pmap_extract(pmap_kernel(), (vm_offset_t) mtime)));
}

startrtclock()
{
	clkstart();
}

void
inittodr()
{
	time_value_t	new_time;

	new_time.seconds = 0;
	new_time.microseconds = 0;

	(void) readtodc(&new_time.seconds);

	{
	    spl_t	s = splhigh();
	    time = new_time;
	    splx(s);
	}
}

void
resettodr()
{
	writetodc();
}

unsigned int pmap_free_pages()
{
	return atop(avail_remaining);
}

/* Always returns page-aligned regions.  */
static boolean_t
init_alloc_aligned(vm_size_t size, vm_offset_t *addrp)
{
	vm_offset_t addr;
	extern char start[], end[];
	int i;
	static int wrapped = 0;

	/* Memory regions to skip.  */
	vm_offset_t cmdline_start_pa = boot_info.flags & MULTIBOOT_CMDLINE
		? boot_info.cmdline : 0;
	vm_offset_t cmdline_end_pa = cmdline_start_pa
		? cmdline_start_pa+strlen((char*)phystokv(cmdline_start_pa))+1
		: 0;
	vm_offset_t mods_start_pa = boot_info.flags & MULTIBOOT_MODS
		? boot_info.mods_addr : 0;
	vm_offset_t mods_end_pa = mods_start_pa
		? mods_start_pa
		  + boot_info.mods_count * sizeof(struct multiboot_module)
		: 0;

	retry:

	/* Page-align the start address.  */
	avail_next = round_page(avail_next);

	/* Start with memory above 16MB, reserving the low memory for later. */
	if (use_all_mem && !wrapped && phys_last_addr > 16 * 1024*1024)
	  {
	    if (avail_next < 16 * 1024*1024)
	      avail_next = 16 * 1024*1024;
	    else if (avail_next == phys_last_addr)
	      {
		/* We have used all the memory above 16MB, so now start on
		   the low memory.  This will wind up at the end of the list
		   of free pages, so it should not have been allocated to any
		   other use in early initialization before the Linux driver
		   glue initialization needs to allocate low memory.  */
		avail_next = 0x1000;
		wrapped = 1;
	      }
	  }

	/* Check if we have reached the end of memory.  */
        if (avail_next == (wrapped ? 16 * 1024*1024 : phys_last_addr))
		return FALSE;

	/* Tentatively assign the current location to the caller.  */
	addr = avail_next;

	/* Bump the pointer past the newly allocated region
	   and see where that puts us.  */
	avail_next += size;

	/* Skip past the I/O and ROM area.  */
	if ((avail_next > (boot_info.mem_lower * 0x400)) && (addr < 0x100000))
	{
		avail_next = 0x100000;
		goto retry;
	}

	/* If we're only supposed to use the low 16 megs, enforce that.  */
	if ((!use_all_mem) && (addr >= 16 * 1024*1024)) {
		return FALSE;
	}

	/* Skip our own kernel code, data, and bss.  */
	if ((avail_next > (vm_offset_t)start) && (addr < (vm_offset_t)end))
	{
		avail_next = (vm_offset_t)end;
		goto retry;
	}

	/* Skip any areas occupied by valuable boot_info data.  */
	if ((avail_next > cmdline_start_pa) && (addr < cmdline_end_pa))
	{
		avail_next = cmdline_end_pa;
		goto retry;
	}
	if ((avail_next > mods_start_pa) && (addr < mods_end_pa))
	{
		avail_next = mods_end_pa;
		goto retry;
	}
	if ((avail_next > kern_sym_start) && (addr < kern_sym_end))
	{
		avail_next = kern_sym_end;
		goto retry;
	}
	if (boot_info.flags & MULTIBOOT_MODS)
	{
		struct multiboot_module *m = (struct multiboot_module *)
			phystokv(boot_info.mods_addr);
		for (i = 0; i < boot_info.mods_count; i++)
		{
			if ((avail_next > m[i].mod_start)
			    && (addr < m[i].mod_end))
			{
				avail_next = m[i].mod_end;
				goto retry;
			}
			/* XXX string */
		}
	}

	avail_remaining -= size;

	*addrp = addr;
	return TRUE;
}

boolean_t pmap_next_page(addrp)
	vm_offset_t *addrp;
{
	return init_alloc_aligned(PAGE_SIZE, addrp);
}

/* Grab a physical page:
   the standard memory allocation mechanism
   during system initialization.  */
vm_offset_t
pmap_grab_page()
{
	vm_offset_t addr;
	if (!pmap_next_page(&addr))
		panic("Not enough memory to initialize Mach");
	return addr;
}

boolean_t pmap_valid_page(x)
	vm_offset_t x;
{
	/* XXX is this OK?  What does it matter for?  */
	return (((phys_first_addr <= x) && (x < phys_last_addr)) &&
		!(((boot_info.mem_lower * 1024) <= x) && (x < 1024*1024)));
}

#ifndef NBBY
#define NBBY	8
#endif
#ifndef NBPW
#define NBPW	(NBBY * sizeof(int))
#endif
#define DMA_MAX	(16*1024*1024)

/*
 * Allocate contiguous pages below 16 MB
 * starting at specified boundary for DMA.
 */
vm_offset_t
alloc_dma_mem(size, align)
	vm_size_t size;
	vm_offset_t align;
{
	int *bits, i, j, k, n;
	int npages, count, bit, mask;
	int first_page, last_page;
	vm_offset_t addr;
	vm_page_t p, prevp;

	npages = round_page(size) / PAGE_SIZE;
	mask = align ? (align - 1) / PAGE_SIZE : 0;

	/*
	 * Allocate bit array.
	 */
	n = ((DMA_MAX / PAGE_SIZE) + NBPW - 1) / NBPW;
	i = n * NBPW;
	bits = (unsigned *)kalloc(i);
	if (bits == 0) {
		printf("alloc_dma_mem: unable alloc bit array\n");
		return (0);
	}
	bzero((char *)bits, i);

	/*
	 * Walk the page free list and set a bit for
	 * every usable page in bit array.
	 */
	simple_lock(&vm_page_queue_free_lock);
	for (p = vm_page_queue_free; p; p = (vm_page_t)p->pageq.next) {
		if (p->phys_addr < DMA_MAX) {
			i = p->phys_addr / PAGE_SIZE;
			bits[i / NBPW] |= 1 << (i % NBPW);
		}
	}

	/*
	 * Search for contiguous pages by scanning bit array.
	 */
	for (i = 0, first_page = -1; i < n; i++) {
		for (bit = 1, j = 0; j < NBPW; j++, bit <<= 1) {
			if (bits[i] & bit) {
				if (first_page < 0) {
					k = i * NBPW + j;
					if (!mask
					    || (((k & mask) + npages)
						<= mask + 1)) {
						first_page = k;
						if (npages == 1)
							goto found;
						count = 1;
					}
				} else if (++count == npages)
					goto found;
			} else
				first_page = -1;
		}
	}
	addr = 0;
	goto out;

 found:
	/*
	 * Remove pages from the free list.
	 */
	addr = first_page * PAGE_SIZE;
	last_page = first_page + npages;
	vm_page_free_count -= npages;
	p = vm_page_queue_free;
	prevp = 0;
	while (1) {
		i = p->phys_addr / PAGE_SIZE;
		if (i >= first_page && i < last_page) {
			if (prevp)
				prevp->pageq.next = p->pageq.next;
			else
				vm_page_queue_free = (vm_page_t)p->pageq.next;
			p->free = FALSE;
			if (--npages == 0)
				break;
		} else
			prevp = p;
		p = (vm_page_t)p->pageq.next;
	}

 out:
	simple_unlock(&vm_page_queue_free_lock);
	kfree((vm_offset_t)bits, n * NBPW);
	return (addr);
}