xref: /netbsd-src/sys/arch/x68k/x68k/pmap_bootstrap.c (revision cb9637bcff0301f3e2d738bcc25a7df416e3259d)
1 /*	$NetBSD: pmap_bootstrap.c,v 1.29 2005/12/11 12:19:45 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * the Systems Programming Group of the University of Utah Computer
9  * Science Department.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)pmap_bootstrap.c	8.1 (Berkeley) 6/10/93
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: pmap_bootstrap.c,v 1.29 2005/12/11 12:19:45 christos Exp $");
40 
41 #include "opt_m680x0.h"
42 
43 #include <sys/param.h>
44 #include <uvm/uvm_extern.h>
45 #include <machine/pte.h>
46 #include <machine/vmparam.h>
47 #include <machine/cpu.h>
48 #include <arch/x68k/x68k/iodevice.h>
49 
50 
51 #define RELOC(v, t)	*((t*)((caddr_t)&(v) + firstpa))
52 
53 extern char *etext;
54 extern int Sysptsize;
55 extern char *proc0paddr;
56 extern st_entry_t *Sysseg;
57 extern pt_entry_t *Sysptmap, *Sysmap;
58 
59 extern int maxmem, physmem;
60 extern paddr_t avail_start, avail_end;
61 extern vaddr_t virtual_avail, virtual_end;
62 extern psize_t mem_size;
63 extern int protection_codes[];
64 
65 u_int8_t *intiobase = (u_int8_t *) PHYS_IODEV;
66 
67 void	pmap_bootstrap(paddr_t, paddr_t);
68 
69 /*
70  * Special purpose kernel virtual addresses, used for mapping
71  * physical pages for a variety of temporary or permanent purposes:
72  *
73  *	CADDR1, CADDR2:	pmap zero/copy operations
74  *	vmmap:		/dev/mem, crash dumps, parity error checking
75  *	msgbufaddr:	kernel message buffer
76  */
77 caddr_t		CADDR1, CADDR2, vmmap;
78 extern caddr_t	msgbufaddr;
79 
80 /*
81  * Bootstrap the VM system.
82  *
83  * Called with MMU off so we must relocate all global references by `firstpa'
84  * (don't call any functions here!)  `nextpa' is the first available physical
85  * memory address.  Returns an updated first PA reflecting the memory we
86  * have allocated.  MMU is still off when we return.
87  *
88  * XXX assumes sizeof(u_int) == sizeof(pt_entry_t)
89  * XXX a PIC compiler would make this much easier.
90  */
91 void
92 pmap_bootstrap(paddr_t nextpa, paddr_t firstpa)
93 {
94 	paddr_t kstpa, kptpa, kptmpa, p0upa;
95 	u_int nptpages, kstsize;
96 	st_entry_t protoste, *ste;
97 	pt_entry_t protopte, *pte, *epte;
98 
99 	/*
100 	 * Calculate important physical addresses:
101 	 *
102 	 *	kstpa		kernel segment table	1 page (!040)
103 	 *						N pages (040)
104 	 *
105 	 *	kptpa		statically allocated
106 	 *			kernel PT pages		Sysptsize+ pages
107 	 *
108 	 * [ Sysptsize is the number of pages of PT, and IIOMAPSIZE
109 	 *   is the number of PTEs, hence we need to round
110 	 *   the total to a page boundary with IO maps at the end. ]
111 	 *
112 	 *	kptmpa		kernel PT map		1 page
113 	 *
114 	 *	p0upa		proc 0 u-area		UPAGES pages
115 	 *
116 	 * The KVA corresponding to any of these PAs is:
117 	 *	(PA - firstpa + KERNBASE).
118 	 */
119 	if (RELOC(mmutype, int) == MMU_68040)
120 		kstsize = MAXKL2SIZE / (NPTEPG/SG4_LEV2SIZE);
121 	else
122 		kstsize = 1;
123 	kstpa = nextpa;
124 	nextpa += kstsize * PAGE_SIZE;
125 	kptmpa = nextpa;
126 	nextpa += PAGE_SIZE;
127 	p0upa = nextpa;
128 	nextpa += USPACE;
129 	kptpa = nextpa;
130 	nptpages = RELOC(Sysptsize, int) +
131 		(IIOMAPSIZE + NPTEPG - 1) / NPTEPG;
132 	nextpa += nptpages * PAGE_SIZE;
133 
134 	/*
135 	 * Clear all PTEs to zero
136 	 */
137 	for (pte = (pt_entry_t *)kstpa; pte < (pt_entry_t *)nextpa; pte++)
138 		*pte = 0;
139 
140 	/*
141 	 * Initialize segment table and kernel page table map.
142 	 *
143 	 * On 68030s and earlier MMUs the two are identical except for
144 	 * the valid bits so both are initialized with essentially the
145 	 * same values.  On the 68040, which has a mandatory 3-level
146 	 * structure, the segment table holds the level 1 table and part
147 	 * (or all) of the level 2 table and hence is considerably
148 	 * different.  Here the first level consists of 128 descriptors
149 	 * (512 bytes) each mapping 32mb of address space.  Each of these
150 	 * points to blocks of 128 second level descriptors (512 bytes)
151 	 * each mapping 256kb.  Note that there may be additional "segment
152 	 * table" pages depending on how large MAXKL2SIZE is.
153 	 *
154 	 * XXX cramming two levels of mapping into the single "segment"
155 	 * table on the 68040 is intended as a temporary hack to get things
156 	 * working.  The 224mb of address space that this allows will most
157 	 * likely be insufficient in the future (at least for the kernel).
158 	 */
159 #if defined(M68040) || defined(M68060)
160 	if (RELOC(mmutype, int) == MMU_68040) {
161 		int num;
162 
163 		/*
164 		 * First invalidate the entire "segment table" pages
165 		 * (levels 1 and 2 have the same "invalid" value).
166 		 */
167 		pte = (u_int *)kstpa;
168 		epte = &pte[kstsize * NPTEPG];
169 		while (pte < epte)
170 			*pte++ = SG_NV;
171 		/*
172 		 * Initialize level 2 descriptors (which immediately
173 		 * follow the level 1 table).  We need:
174 		 *	NPTEPG / SG4_LEV3SIZE
175 		 * level 2 descriptors to map each of the nptpages
176 		 * pages of PTEs.  Note that we set the "used" bit
177 		 * now to save the HW the expense of doing it.
178 		 */
179 		num = nptpages * (NPTEPG / SG4_LEV3SIZE);
180 		pte = &((u_int *)kstpa)[SG4_LEV1SIZE];
181 		epte = &pte[num];
182 		protoste = kptpa | SG_U | SG_RW | SG_V;
183 		while (pte < epte) {
184 			*pte++ = protoste;
185 			protoste += (SG4_LEV3SIZE * sizeof(st_entry_t));
186 		}
187 		/*
188 		 * Initialize level 1 descriptors.  We need:
189 		 *	roundup(num, SG4_LEV2SIZE) / SG4_LEV2SIZE
190 		 * level 1 descriptors to map the `num' level 2's.
191 		 */
192 		pte = (u_int *)kstpa;
193 		epte = &pte[roundup(num, SG4_LEV2SIZE) / SG4_LEV2SIZE];
194 		protoste = (u_int)&pte[SG4_LEV1SIZE] | SG_U | SG_RW | SG_V;
195 		while (pte < epte) {
196 			*pte++ = protoste;
197 			protoste += (SG4_LEV2SIZE * sizeof(st_entry_t));
198 		}
199 		/*
200 		 * Initialize the final level 1 descriptor to map the last
201 		 * block of level 2 descriptors.
202 		 */
203 		ste = &((u_int *)kstpa)[SG4_LEV1SIZE-1];
204 		pte = &((u_int *)kstpa)[kstsize*NPTEPG - SG4_LEV2SIZE];
205 		*ste = (u_int)pte | SG_U | SG_RW | SG_V;
206 		/*
207 		 * Now initialize the final portion of that block of
208 		 * descriptors to map kptmpa.
209 		 */
210 		pte = &((u_int *)kstpa)[kstsize*NPTEPG - NPTEPG/SG4_LEV3SIZE];
211 		epte = &pte[NPTEPG/SG4_LEV3SIZE];
212 		protoste = kptmpa | SG_U | SG_RW | SG_V;
213 		while (pte < epte) {
214 			*pte++ = protoste;
215 			protoste += (SG4_LEV3SIZE * sizeof(st_entry_t));
216 		}
217 		/*
218 		 * Initialize Sysptmap
219 		 */
220 		pte = (u_int *)kptmpa;
221 		epte = &pte[nptpages];
222 		protopte = kptpa | PG_RW | PG_CI | PG_V;
223 		while (pte < epte) {
224 			*pte++ = protopte;
225 			protopte += PAGE_SIZE;
226 		}
227 		/*
228 		 * Invalidate all but the last remaining entry.
229 		 */
230 		epte = &((u_int *)kptmpa)[NPTEPG-1];
231 		while (pte < epte) {
232 			*pte++ = PG_NV;
233 		}
234 		/*
235 		 * Initialize the last one to point to Sysptmap.
236 		 */
237 		*pte = kptmpa | PG_RW | PG_CI | PG_V;
238 	} else
239 #endif /* M68040 || M68060 */
240 	{
241 		/*
242 		 * Map the page table pages in both the HW segment table
243 		 * and the software Sysptmap.
244 		 */
245 		ste = (u_int *)kstpa;
246 		pte = (u_int *)kptmpa;
247 		epte = &pte[nptpages];
248 		protoste = kptpa | SG_RW | SG_V;
249 		protopte = kptpa | PG_RW | PG_CI | PG_V;
250 		while (pte < epte) {
251 			*ste++ = protoste;
252 			*pte++ = protopte;
253 			protoste += PAGE_SIZE;
254 			protopte += PAGE_SIZE;
255 		}
256 		/*
257 		 * Invalidate all but the last remaining entries in both.
258 		 */
259 		epte = &((u_int *)kptmpa)[NPTEPG-1];
260 		while (pte < epte) {
261 			*ste++ = SG_NV;
262 			*pte++ = PG_NV;
263 		}
264  		/*
265 		 * Initialize the last one to point to Sysptmap.
266  		 */
267 		*ste = kptmpa | SG_RW | SG_V;
268 		*pte = kptmpa | PG_RW | PG_CI | PG_V;
269 	}
270 
271 	/*
272 	 * Initialize kernel page table.
273 	 * Start by invalidating the `nptpages' that we have allocated.
274 	 */
275 	pte = (u_int *)kptpa;
276 	epte = &pte[nptpages * NPTEPG];
277 	while (pte < epte)
278 		*pte++ = PG_NV;
279 	/*
280 	 * Validate PTEs for kernel text (RO)
281 	 */
282 	pte = &((u_int *)kptpa)[m68k_btop(KERNBASE)];
283 	/* XXX why KERNBASE relative? */
284 	epte = &pte[m68k_btop(m68k_trunc_page(&etext))];
285 	protopte = firstpa | PG_RO | PG_V;
286 	while (pte < epte) {
287 		*pte++ = protopte;
288 		protopte += PAGE_SIZE;
289 	}
290 	/*
291 	 * Validate PTEs for kernel data/bss, dynamic data allocated
292 	 * by us so far (kstpa - firstpa bytes), and pages for proc0
293 	 * u-area and page table allocated below (RW).
294 	 */
295 	epte = &((u_int *)kptpa)[m68k_btop(kstpa - firstpa)];
296 	protopte = (protopte & ~PG_PROT) | PG_RW;
297 	/*
298 	 * Enable copy-back caching of data pages
299 	 */
300 	if (RELOC(mmutype, int) == MMU_68040)
301 		protopte |= PG_CCB;
302 	while (pte < epte) {
303 		*pte++ = protopte;
304 		protopte += PAGE_SIZE;
305 	}
306 	/*
307 	 * map the kernel segment table cache invalidated for
308 	 * these machines (for the 68040 not strictly necessary, but
309 	 * recommended by Motorola; for the 68060 mandatory)
310 	 * XXX this includes p0upa.  why?
311 	 */
312 	epte = &((u_int *)kptpa)[m68k_btop(nextpa - firstpa)];
313 	protopte = (protopte & ~PG_PROT) | PG_RW;
314 	if (RELOC(mmutype, int) == MMU_68040) {
315 		protopte &= ~PG_CCB;
316 		protopte |= PG_CIN;
317 	}
318 	while (pte < epte) {
319 		*pte++ = protopte;
320 		protopte += PAGE_SIZE;
321 	}
322 
323 	/*
324 	 * Finally, validate the internal IO space PTEs (RW+CI).
325 	 */
326 
327 #define	PTE2VA(pte)	m68k_ptob(pte - ((pt_entry_t *)kptpa))
328 
329 	protopte = INTIOBASE | PG_RW | PG_CI | PG_V;
330 	epte = &pte[IIOMAPSIZE];
331 	RELOC(IODEVbase, char *) = (char *)PTE2VA(pte);
332 	RELOC(intiobase, u_int8_t *) = RELOC(IODEVbase, u_int8_t *); /* XXX */
333 	RELOC(intiolimit, char *) = (char *)PTE2VA(epte);
334 	while (pte < epte) {
335 		*pte++ = protopte;
336 		protopte += PAGE_SIZE;
337 	}
338 	RELOC(virtual_avail, vaddr_t) = PTE2VA(pte);
339 
340 	/*
341 	 * Calculate important exported kernel virtual addresses
342 	 */
343 	/*
344 	 * Sysseg: base of kernel segment table
345 	 */
346 	RELOC(Sysseg, st_entry_t *) =
347 		(st_entry_t *)(kstpa - firstpa);
348 	/*
349 	 * Sysptmap: base of kernel page table map
350 	 */
351 	RELOC(Sysptmap, pt_entry_t *) =
352 		(pt_entry_t *)(kptmpa - firstpa);
353 	/*
354 	 * Sysmap: kernel page table (as mapped through Sysptmap)
355 	 * Immediately follows `nptpages' of static kernel page table.
356 	 */
357 	RELOC(Sysmap, pt_entry_t *) =
358 	    (pt_entry_t *)m68k_ptob((NPTEPG - 1) * NPTEPG);
359 
360 	/*
361 	 * Setup u-area for process 0.
362 	 */
363 	/*
364 	 * Zero the u-area.
365 	 * NOTE: `pte' and `epte' aren't PTEs here.
366 	 */
367 	pte = (u_int *)p0upa;
368 	epte = (u_int *)(p0upa + USPACE);
369 	while (pte < epte)
370 		*pte++ = 0;
371 	/*
372 	 * Remember the u-area address so it can be loaded in the
373 	 * proc struct p_addr field later.
374 	 */
375 	RELOC(proc0paddr, char *) = (char *)(p0upa - firstpa);
376 
377 	/*
378 	 * VM data structures are now initialized, set up data for
379 	 * the pmap module.
380 	 */
381 	RELOC(avail_start, paddr_t) = nextpa;
382 	RELOC(avail_end, paddr_t) =
383 		m68k_ptob(RELOC(maxmem, int))
384 			/* XXX allow for msgbuf */
385 			- m68k_round_page(MSGBUFSIZE);
386 	RELOC(mem_size, psize_t) = m68k_ptob(RELOC(physmem, int));
387 	RELOC(virtual_end, vaddr_t) = VM_MAX_KERNEL_ADDRESS;
388 
389 	/*
390 	 * Initialize protection array.
391 	 * XXX don't use a switch statement, it might produce an
392 	 * absolute "jmp" table.
393 	 */
394 	{
395 		int *kp;
396 
397 		kp = &RELOC(protection_codes, int);
398 		kp[VM_PROT_NONE|VM_PROT_NONE|VM_PROT_NONE] = 0;
399 		kp[VM_PROT_READ|VM_PROT_NONE|VM_PROT_NONE] = PG_RO;
400 		kp[VM_PROT_READ|VM_PROT_NONE|VM_PROT_EXECUTE] = PG_RO;
401 		kp[VM_PROT_NONE|VM_PROT_NONE|VM_PROT_EXECUTE] = PG_RO;
402 		kp[VM_PROT_NONE|VM_PROT_WRITE|VM_PROT_NONE] = PG_RW;
403 		kp[VM_PROT_NONE|VM_PROT_WRITE|VM_PROT_EXECUTE] = PG_RW;
404 		kp[VM_PROT_READ|VM_PROT_WRITE|VM_PROT_NONE] = PG_RW;
405 		kp[VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE] = PG_RW;
406 	}
407 
408 	/*
409 	 * Kernel page/segment table allocated above,
410 	 * just initialize pointers.
411 	 */
412 	{
413 		struct pmap *kpm = &RELOC(kernel_pmap_store, struct pmap);
414 
415 		kpm->pm_stab = RELOC(Sysseg, st_entry_t *);
416 		kpm->pm_ptab = RELOC(Sysmap, pt_entry_t *);
417 		simple_lock_init(&kpm->pm_lock);
418 		kpm->pm_count = 1;
419 		kpm->pm_stpa = (st_entry_t *)kstpa;
420 #if defined(M68040) || defined(M68060)
421 		/*
422 		 * For the 040 we also initialize the free level 2
423 		 * descriptor mask noting that we have used:
424 		 *	0:		level 1 table
425 		 *	1 to `num':	map page tables
426 		 *	MAXKL2SIZE-1:	maps kptmpa and last-page page table
427 		 */
428 		if (RELOC(mmutype, int) == MMU_68040) {
429 			int num;
430 
431 			kpm->pm_stfree = ~l2tobm(0);
432 			num = roundup(nptpages * (NPTEPG / SG4_LEV3SIZE),
433 				      SG4_LEV2SIZE) / SG4_LEV2SIZE;
434 			while (num)
435 				kpm->pm_stfree &= ~l2tobm(num--);
436 			kpm->pm_stfree &= ~l2tobm(MAXKL2SIZE-1);
437 			for (num = MAXKL2SIZE;
438 			     num < sizeof(kpm->pm_stfree)*NBBY;
439 			     num++)
440 				kpm->pm_stfree &= ~l2tobm(num);
441 		}
442 #endif
443 	}
444 
445 	/*
446 	 * Allocate some fixed, special purpose kernel virtual addresses
447 	 */
448 	{
449 		vaddr_t va = RELOC(virtual_avail, vaddr_t);
450 
451 		RELOC(CADDR1, caddr_t) = (caddr_t)va;
452 		va += PAGE_SIZE;
453 		RELOC(CADDR2, caddr_t) = (caddr_t)va;
454 		va += PAGE_SIZE;
455 		RELOC(vmmap, caddr_t) = (caddr_t)va;
456 		va += PAGE_SIZE;
457 		RELOC(msgbufaddr, caddr_t) = (caddr_t)va;
458 		va += m68k_round_page(MSGBUFSIZE);
459 		RELOC(virtual_avail, vaddr_t) = va;
460 	}
461 }
462