xref: /titanic_41/usr/src/uts/i86pc/vm/kboot_mmu.c (revision 5ce5f3670f7934e376808da0d1309924ecf8f9e5)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/systm.h>
31 #include <sys/archsystm.h>
32 #include <sys/debug.h>
33 #include <sys/bootconf.h>
34 #include <sys/bootsvcs.h>
35 #include <sys/bootinfo.h>
36 #include <sys/mman.h>
37 #include <sys/cmn_err.h>
38 #include <sys/param.h>
39 #include <sys/machparam.h>
40 #include <sys/machsystm.h>
41 #include <sys/promif.h>
42 #include <sys/kobj.h>
43 #include <vm/kboot_mmu.h>
44 #include <vm/hat_pte.h>
45 #include <vm/hat_i86.h>
46 #include <vm/seg_kmem.h>
47 
48 #if 0
49 /*
50  * Joe's debug printing
51  */
52 #define	DBG(x)    \
53 	bop_printf(NULL, "boot_mmu.c: %s is %" PRIx64 "\n", #x, (uint64_t)(x));
54 #else
55 #define	DBG(x)	/* naught */
56 #endif
57 
58 /*
59  * Page table and memory stuff.
60  */
61 static caddr_t window;
62 static caddr_t pte_to_window;
63 
64 /*
65  * this are needed by mmu_init()
66  */
67 int kbm_nx_support = 0;		/* NX bit in PTEs is in use */
68 int kbm_pae_support = 0;	/* PAE is 64 bit Page table entries */
69 int kbm_pge_support = 0;	/* PGE is Page table global bit enabled */
70 int kbm_largepage_support = 0;
71 uint_t kbm_nucleus_size = 0;
72 
73 #define	BOOT_SHIFT(l)	(shift_amt[l])
74 #define	BOOT_SZ(l)	((size_t)1 << BOOT_SHIFT(l))
75 #define	BOOT_OFFSET(l)	(BOOT_SZ(l) - 1)
76 #define	BOOT_MASK(l)	(~BOOT_OFFSET(l))
77 
78 /*
79  * Initialize memory management parameters for boot time page table management
80  */
81 void
82 kbm_init(struct xboot_info *bi)
83 {
84 	/*
85 	 * configure mmu information
86 	 */
87 	kbm_nucleus_size = (uintptr_t)bi->bi_kseg_size;
88 	kbm_largepage_support = bi->bi_use_largepage;
89 	kbm_nx_support = bi->bi_use_nx;
90 	kbm_pae_support = bi->bi_use_pae;
91 	kbm_pge_support = bi->bi_use_pge;
92 	window = bi->bi_pt_window;
93 	DBG(window);
94 	pte_to_window = bi->bi_pte_to_pt_window;
95 	DBG(pte_to_window);
96 	if (kbm_pae_support) {
97 		shift_amt = shift_amt_pae;
98 		ptes_per_table = 512;
99 		pte_size = 8;
100 		lpagesize = TWO_MEG;
101 #ifdef __amd64
102 		top_level = 3;
103 #else
104 		top_level = 2;
105 #endif
106 	} else {
107 		shift_amt = shift_amt_nopae;
108 		ptes_per_table = 1024;
109 		pte_size = 4;
110 		lpagesize = FOUR_MEG;
111 		top_level = 1;
112 	}
113 
114 	top_page_table = bi->bi_top_page_table;
115 	DBG(top_page_table);
116 }
117 
118 /*
119  * Change the addressible page table window to point at a given page
120  */
121 /*ARGSUSED*/
122 void *
123 kbm_remap_window(paddr_t physaddr, int writeable)
124 {
125 	uint_t pt_bits = PT_NOCONSIST | PT_VALID | PT_WRITABLE;
126 
127 	DBG(physaddr);
128 
129 	if (kbm_pae_support)
130 		*((x86pte_t *)pte_to_window) = physaddr | pt_bits;
131 	else
132 		*((x86pte32_t *)pte_to_window) = physaddr | pt_bits;
133 	mmu_tlbflush_entry(window);
134 	DBG(window);
135 	return (window);
136 }
137 
138 /*
139  * Add a mapping for the physical page at the given virtual address.
140  */
141 void
142 kbm_map(uintptr_t va, paddr_t pa, uint_t level, uint_t is_kernel)
143 {
144 	x86pte_t *ptep;
145 	paddr_t pte_physaddr;
146 	x86pte_t pteval;
147 
148 	if (khat_running)
149 		panic("kbm_map() called too late");
150 
151 	pteval = pa_to_ma(pa) | PT_NOCONSIST | PT_VALID | PT_WRITABLE;
152 	if (level == 1)
153 		pteval |= PT_PAGESIZE;
154 	if (kbm_pge_support && is_kernel)
155 		pteval |= PT_GLOBAL;
156 
157 	/*
158 	 * Find the pte that will map this address. This creates any
159 	 * missing intermediate level page tables.
160 	 */
161 	ptep = find_pte(va, &pte_physaddr, level, 0);
162 	if (ptep == NULL)
163 		bop_panic("kbm_map: find_pte returned NULL");
164 
165 	if (kbm_pae_support)
166 		*ptep = pteval;
167 	else
168 		*((x86pte32_t *)ptep) = pteval;
169 	mmu_tlbflush_entry((caddr_t)va);
170 }
171 
172 /*
173  * Probe the boot time page tables to find the first mapping
174  * including va (or higher) and return non-zero if one is found.
175  * va is updated to the starting address and len to the pagesize.
176  * pp will be set to point to the 1st page_t of the mapped page(s).
177  *
178  * Note that if va is in the middle of a large page, the returned va
179  * will be less than what was asked for.
180  */
181 int
182 kbm_probe(uintptr_t *va, size_t *len, pfn_t *pfn, uint_t *prot)
183 {
184 	uintptr_t	probe_va;
185 	x86pte_t	*ptep;
186 	paddr_t		pte_physaddr;
187 	x86pte_t	pte_val;
188 	level_t		l;
189 
190 	if (khat_running)
191 		panic("kbm_probe() called too late");
192 	*len = 0;
193 	*pfn = PFN_INVALID;
194 	*prot = 0;
195 	probe_va = *va;
196 restart_new_va:
197 	l = top_level;
198 	for (;;) {
199 		if (IN_VA_HOLE(probe_va))
200 			probe_va = mmu.hole_end;
201 
202 		if (IN_HYPERVISOR_VA(probe_va))
203 			return (0);
204 
205 		/*
206 		 * If we don't have a valid PTP/PTE at this level
207 		 * then we can bump VA by this level's pagesize and try again.
208 		 * When the probe_va wraps around, we are done.
209 		 */
210 		ptep = find_pte(probe_va, &pte_physaddr, l, 1);
211 		if (ptep == NULL)
212 			bop_panic("kbm_probe: find_pte returned NULL");
213 		if (kbm_pae_support)
214 			pte_val = *ptep;
215 		else
216 			pte_val = *((x86pte32_t *)ptep);
217 		if (!PTE_ISVALID(pte_val)) {
218 			probe_va = (probe_va & BOOT_MASK(l)) + BOOT_SZ(l);
219 			if (probe_va <= *va)
220 				return (0);
221 			goto restart_new_va;
222 		}
223 
224 		/*
225 		 * If this entry is a pointer to a lower level page table
226 		 * go down to it.
227 		 */
228 		if (!PTE_ISPAGE(pte_val, l)) {
229 			ASSERT(l > 0);
230 			--l;
231 			continue;
232 		}
233 
234 		/*
235 		 * We found a boot level page table entry
236 		 */
237 		*len = BOOT_SZ(l);
238 		*va = probe_va & ~(*len - 1);
239 		*pfn = PTE2PFN(pte_val, l);
240 
241 
242 		*prot = PROT_READ | PROT_EXEC;
243 		if (PTE_GET(pte_val, PT_WRITABLE))
244 			*prot |= PROT_WRITE;
245 
246 		/*
247 		 * pt_nx is cleared if processor doesn't support NX bit
248 		 */
249 		if (PTE_GET(pte_val, mmu.pt_nx))
250 			*prot &= ~PROT_EXEC;
251 
252 		return (1);
253 	}
254 }
255 
256 
257 /*
258  * Destroy a boot loader page table 4K mapping.
259  */
260 void
261 kbm_unmap(uintptr_t va)
262 {
263 	if (khat_running)
264 		panic("kbm_unmap() called too late");
265 	else {
266 		x86pte_t *ptep;
267 		level_t	level = 0;
268 		uint_t  probe_only = 1;
269 
270 		ptep = find_pte(va, NULL, level, probe_only);
271 		if (ptep == NULL)
272 			return;
273 
274 		if (kbm_pae_support)
275 			*ptep = 0;
276 		else
277 			*((x86pte32_t *)ptep) = 0;
278 		mmu_tlbflush_entry((caddr_t)va);
279 	}
280 }
281 
282 
283 /*
284  * Change a boot loader page table 4K mapping.
285  * Returns the pfn of the old mapping.
286  */
287 pfn_t
288 kbm_remap(uintptr_t va, pfn_t pfn)
289 {
290 	x86pte_t *ptep;
291 	level_t	level = 0;
292 	uint_t  probe_only = 1;
293 	x86pte_t pte_val = pa_to_ma(pfn_to_pa(pfn)) | PT_WRITABLE |
294 	    PT_NOCONSIST | PT_VALID;
295 	x86pte_t old_pte;
296 
297 	if (khat_running)
298 		panic("kbm_remap() called too late");
299 	ptep = find_pte(va, NULL, level, probe_only);
300 	if (ptep == NULL)
301 		bop_panic("kbm_remap: find_pte returned NULL");
302 
303 	if (kbm_pae_support)
304 		old_pte = *ptep;
305 	else
306 		old_pte = *((x86pte32_t *)ptep);
307 
308 	if (kbm_pae_support)
309 		*((x86pte_t *)ptep) = pte_val;
310 	else
311 		*((x86pte32_t *)ptep) = pte_val;
312 	mmu_tlbflush_entry((caddr_t)va);
313 
314 	if (!(old_pte & PT_VALID) || ma_to_pa(old_pte) == -1)
315 		return (PFN_INVALID);
316 	return (mmu_btop(ma_to_pa(old_pte)));
317 }
318 
319 
320 /*
321  * Change a boot loader page table 4K mapping to read only.
322  */
323 void
324 kbm_read_only(uintptr_t va, paddr_t pa)
325 {
326 	x86pte_t pte_val = pa_to_ma(pa) |
327 	    PT_NOCONSIST | PT_REF | PT_MOD | PT_VALID;
328 	x86pte_t *ptep;
329 	level_t	level = 0;
330 
331 	ptep = find_pte(va, NULL, level, 0);
332 	if (ptep == NULL)
333 		bop_panic("kbm_read_only: find_pte returned NULL");
334 
335 	if (kbm_pae_support)
336 		*ptep = pte_val;
337 	else
338 		*((x86pte32_t *)ptep) = pte_val;
339 	mmu_tlbflush_entry((caddr_t)va);
340 }
341 
342 /*
343  * interfaces for kernel debugger to access physical memory
344  */
345 static x86pte_t save_pte;
346 
347 void *
348 kbm_push(paddr_t pa)
349 {
350 	static int first_time = 1;
351 
352 	if (first_time) {
353 		first_time = 0;
354 		return (window);
355 	}
356 
357 	if (kbm_pae_support)
358 		save_pte = *((x86pte_t *)pte_to_window);
359 	else
360 		save_pte = *((x86pte32_t *)pte_to_window);
361 	return (kbm_remap_window(pa, 0));
362 }
363 
364 void
365 kbm_pop(void)
366 {
367 	if (kbm_pae_support)
368 		*((x86pte_t *)pte_to_window) = save_pte;
369 	else
370 		*((x86pte32_t *)pte_to_window) = save_pte;
371 	mmu_tlbflush_entry(window);
372 }
373 
374 x86pte_t
375 get_pteval(paddr_t table, uint_t index)
376 {
377 	void *table_ptr = kbm_remap_window(table, 0);
378 
379 	if (kbm_pae_support)
380 		return (((x86pte_t *)table_ptr)[index]);
381 	return (((x86pte32_t *)table_ptr)[index]);
382 }
383 
384 void
385 set_pteval(paddr_t table, uint_t index, uint_t level, x86pte_t pteval)
386 {
387 	void *table_ptr = kbm_remap_window(table, 0);
388 	if (kbm_pae_support)
389 		((x86pte_t *)table_ptr)[index] = pteval;
390 	else
391 		((x86pte32_t *)table_ptr)[index] = pteval;
392 	if (level == top_level && level == 2)
393 		reload_cr3();
394 }
395 
396 paddr_t
397 make_ptable(x86pte_t *pteval, uint_t level)
398 {
399 	paddr_t new_table;
400 	void *table_ptr;
401 
402 	new_table = do_bop_phys_alloc(MMU_PAGESIZE, MMU_PAGESIZE);
403 	table_ptr = kbm_remap_window(new_table, 1);
404 	bzero(table_ptr, MMU_PAGESIZE);
405 
406 	if (level == top_level && level == 2)
407 		*pteval = pa_to_ma(new_table) | PT_VALID;
408 	else
409 		*pteval = pa_to_ma(new_table) |
410 		    PT_VALID | PT_REF | PT_USER | PT_WRITABLE;
411 
412 	return (new_table);
413 }
414 
415 x86pte_t *
416 map_pte(paddr_t table, uint_t index)
417 {
418 	void *table_ptr = kbm_remap_window(table, 0);
419 	return ((x86pte_t *)((caddr_t)table_ptr + index * pte_size));
420 }
421