xref: /titanic_44/usr/src/uts/sun4u/io/pci/pci_iommu.c (revision 1cb6af97c6f66f456d4f726ef056e1ebc0f73305)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 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 /*
30  * PCI iommu initialization and configuration
31  */
32 
33 #include <sys/types.h>
34 #include <sys/kmem.h>
35 #include <sys/async.h>
36 #include <sys/sysmacros.h>
37 #include <sys/sunddi.h>
38 #include <sys/ddi_impldefs.h>
39 #include <sys/vmem.h>
40 #include <sys/machsystm.h>	/* lddphys() */
41 #include <sys/iommutsb.h>
42 #include <sys/pci/pci_obj.h>
43 
44 /*LINTLIBRARY*/
45 
46 static void iommu_tlb_flushall(iommu_t *iommu_p);
47 static void iommu_preserve_tsb(iommu_t *iommu_p);
48 
49 void
50 iommu_create(pci_t *pci_p)
51 {
52 	dev_info_t *dip = pci_p->pci_dip;
53 	iommu_t *iommu_p;
54 	uintptr_t a;
55 	size_t cache_size;
56 	uint32_t tsb_entries;
57 
58 	char map_name[32];
59 	extern uint64_t va_to_pa(void *);
60 
61 	pci_dvma_range_prop_t	pci_dvma_range;
62 
63 	/*
64 	 * Allocate iommu state structure and link it to the
65 	 * pci state structure.
66 	 */
67 	iommu_p = (iommu_t *)kmem_zalloc(sizeof (iommu_t), KM_SLEEP);
68 	pci_p->pci_iommu_p = iommu_p;
69 	iommu_p->iommu_pci_p = pci_p;
70 	iommu_p->iommu_inst = ddi_get_instance(dip);
71 
72 	/*
73 	 * chip specific dvma_end, tsb_size & context support
74 	 */
75 	iommu_p->iommu_dvma_end = pci_iommu_dvma_end;
76 	a = pci_iommu_setup(iommu_p);
77 
78 	/*
79 	 * Determine the virtual address of iommu registers.
80 	 */
81 	iommu_p->iommu_ctrl_reg =
82 		(uint64_t *)(a + COMMON_IOMMU_CTRL_REG_OFFSET);
83 	iommu_p->iommu_tsb_base_addr_reg =
84 		(uint64_t *)(a + COMMON_IOMMU_TSB_BASE_ADDR_REG_OFFSET);
85 	iommu_p->iommu_flush_page_reg =
86 		(uint64_t *)(a + COMMON_IOMMU_FLUSH_PAGE_REG_OFFSET);
87 
88 	/*
89 	 * Configure the rest of the iommu parameters according to:
90 	 * tsb_size and dvma_end
91 	 */
92 	iommu_p->iommu_tsb_vaddr = /* retrieve TSB VA reserved by system */
93 		iommu_tsb_cookie_to_va(pci_p->pci_tsb_cookie);
94 	iommu_p->iommu_tsb_entries = tsb_entries =
95 		IOMMU_TSBSIZE_TO_TSBENTRIES(iommu_p->iommu_tsb_size);
96 	iommu_p->iommu_tsb_paddr = va_to_pa((caddr_t)iommu_p->iommu_tsb_vaddr);
97 	iommu_p->iommu_dvma_cache_locks =
98 		kmem_zalloc(pci_dvma_page_cache_entries, KM_SLEEP);
99 
100 	iommu_p->iommu_dvma_base = iommu_p->iommu_dvma_end + 1
101 		- (tsb_entries * IOMMU_PAGE_SIZE);
102 	iommu_p->dvma_base_pg = IOMMU_BTOP(iommu_p->iommu_dvma_base);
103 	iommu_p->iommu_dvma_reserve = tsb_entries >> 1;
104 	iommu_p->dvma_end_pg = IOMMU_BTOP(iommu_p->iommu_dvma_end);
105 	iommu_p->iommu_dma_bypass_base = COMMON_IOMMU_BYPASS_BASE;
106 	iommu_p->iommu_dma_bypass_end = COMMON_IOMMU_BYPASS_END;
107 
108 	/*
109 	 * export "virtual-dma" software property to support
110 	 * child devices needing to know DVMA range
111 	 */
112 	pci_dvma_range.dvma_base = (uint32_t)iommu_p->iommu_dvma_base;
113 	pci_dvma_range.dvma_len = (uint32_t)
114 		iommu_p->iommu_dvma_end - iommu_p->iommu_dvma_base + 1;
115 	(void) ddi_prop_create(DDI_DEV_T_NONE, dip, DDI_PROP_CANSLEEP,
116 		"virtual-dma", (caddr_t)&pci_dvma_range,
117 		sizeof (pci_dvma_range));
118 
119 	DEBUG2(DBG_ATTACH, dip, "iommu_create: ctrl=%p, tsb=%p\n",
120 		iommu_p->iommu_ctrl_reg, iommu_p->iommu_tsb_base_addr_reg);
121 	DEBUG2(DBG_ATTACH, dip, "iommu_create: page_flush=%p, ctx_flush=%p\n",
122 		iommu_p->iommu_flush_page_reg, iommu_p->iommu_flush_ctx_reg);
123 	DEBUG2(DBG_ATTACH, dip, "iommu_create: tsb vaddr=%p tsb_paddr=%p\n",
124 		iommu_p->iommu_tsb_vaddr, iommu_p->iommu_tsb_paddr);
125 	DEBUG1(DBG_ATTACH, dip, "iommu_create: allocated size=%x\n",
126 		iommu_tsb_cookie_to_size(pci_p->pci_tsb_cookie));
127 	DEBUG2(DBG_ATTACH, dip, "iommu_create: fast tsb tte addr: %x + %x\n",
128 		iommu_p->iommu_tsb_vaddr,
129 		pci_dvma_page_cache_entries * pci_dvma_page_cache_clustsz);
130 	DEBUG3(DBG_ATTACH, dip,
131 		"iommu_create: tsb size=%x, tsb entries=%x, dvma base=%x\n",
132 		iommu_p->iommu_tsb_size, iommu_p->iommu_tsb_entries,
133 		iommu_p->iommu_dvma_base);
134 	DEBUG2(DBG_ATTACH, dip,
135 		"iommu_create: dvma_cache_locks=%x cache_entries=%x\n",
136 		iommu_p->iommu_dvma_cache_locks, pci_dvma_page_cache_entries);
137 
138 	/*
139 	 * zero out the area to be used for iommu tsb
140 	 */
141 	bzero(iommu_p->iommu_tsb_vaddr, tsb_entries << 3);
142 
143 	/*
144 	 * Create a virtual memory map for dvma address space.
145 	 * Reserve 'size' bytes of low dvma space for fast track cache.
146 	 */
147 	(void) snprintf(map_name, sizeof (map_name), "%s%d_dvma",
148 		ddi_driver_name(dip), ddi_get_instance(dip));
149 
150 	cache_size = IOMMU_PTOB(pci_dvma_page_cache_entries *
151 		pci_dvma_page_cache_clustsz);
152 	iommu_p->iommu_dvma_fast_end = iommu_p->iommu_dvma_base +
153 		cache_size - 1;
154 	iommu_p->iommu_dvma_map = vmem_create(map_name,
155 		(void *)(iommu_p->iommu_dvma_fast_end + 1),
156 		IOMMU_PTOB(tsb_entries) - cache_size, IOMMU_PAGE_SIZE,
157 		NULL, NULL, NULL, IOMMU_PAGE_SIZE, VM_SLEEP);
158 
159 	mutex_init(&iommu_p->dvma_debug_lock, NULL, MUTEX_DRIVER, NULL);
160 
161 	/*
162 	 * On detach, the TSB Base Address Register gets set to zero,
163 	 * so if its zero here, there is no need to preserve TTEs.
164 	 */
165 	if (pci_preserve_iommu_tsb && *iommu_p->iommu_tsb_base_addr_reg)
166 		iommu_preserve_tsb(iommu_p);
167 
168 	iommu_configure(iommu_p);
169 }
170 
171 void
172 iommu_destroy(pci_t *pci_p)
173 {
174 #ifdef DEBUG
175 	dev_info_t *dip = pci_p->pci_dip;
176 #endif
177 	iommu_t *iommu_p = pci_p->pci_iommu_p;
178 	volatile uint64_t ctl_val = *iommu_p->iommu_ctrl_reg;
179 
180 	DEBUG0(DBG_DETACH, dip, "iommu_destroy:\n");
181 
182 	/*
183 	 * Disable the IOMMU by setting the TSB Base Address to zero
184 	 * and the TSB Table size to the smallest possible.
185 	 */
186 	ctl_val = ctl_val & ~(7 << COMMON_IOMMU_CTRL_TSB_SZ_SHIFT);
187 
188 	*iommu_p->iommu_ctrl_reg = ctl_val;
189 	*iommu_p->iommu_tsb_base_addr_reg = 0;
190 
191 	/*
192 	 * Return the boot time allocated tsb.
193 	 */
194 	iommu_tsb_free(pci_p->pci_tsb_cookie);
195 
196 	/*
197 	 * Teardown any implementation-specific structures set up in
198 	 * pci_iommu_setup.
199 	 */
200 	pci_iommu_teardown(iommu_p);
201 
202 	if (DVMA_DBG_ON(iommu_p))
203 		pci_dvma_debug_fini(iommu_p);
204 	mutex_destroy(&iommu_p->dvma_debug_lock);
205 
206 	/*
207 	 * Free the dvma resource map.
208 	 */
209 	vmem_destroy(iommu_p->iommu_dvma_map);
210 
211 	kmem_free(iommu_p->iommu_dvma_cache_locks,
212 	    pci_dvma_page_cache_entries);
213 
214 	/*
215 	 * Free the iommu state structure.
216 	 */
217 	kmem_free(iommu_p, sizeof (iommu_t));
218 	pci_p->pci_iommu_p = NULL;
219 }
220 
221 /*
222  * re-program iommu on the fly while preserving on-going dma
223  * transactions on the PCI bus.
224  */
225 void
226 iommu_configure(iommu_t *iommu_p)
227 {
228 	pci_t *pci_p = iommu_p->iommu_pci_p;
229 	uint64_t cfgpa = pci_get_cfg_pabase(pci_p);
230 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
231 	dev_info_t *cdip = NULL;
232 	volatile uint64_t ctl_val = (uint64_t)
233 		((iommu_p->iommu_tsb_size << COMMON_IOMMU_CTRL_TSB_SZ_SHIFT) |
234 			(0 /* 8k page */ << COMMON_IOMMU_CTRL_TBW_SZ_SHIFT) |
235 			COMMON_IOMMU_CTRL_ENABLE |
236 			COMMON_IOMMU_CTRL_DIAG_ENABLE |
237 			(pci_lock_tlb ? COMMON_IOMMU_CTRL_LCK_ENABLE : 0));
238 
239 	DEBUG2(DBG_ATTACH, dip, "iommu_configure: iommu_ctl=%08x.%08x\n",
240 		HI32(ctl_val), LO32(ctl_val));
241 	if (!pci_preserve_iommu_tsb || !(*iommu_p->iommu_tsb_base_addr_reg)) {
242 		*iommu_p->iommu_ctrl_reg = COMMON_IOMMU_CTRL_DIAG_ENABLE;
243 		iommu_tlb_flushall(iommu_p);
244 		goto config;
245 	}
246 	cdip = ddi_get_child(dip);
247 	for (; cdip; cdip = ddi_get_next_sibling(cdip)) {
248 		uint32_t *reg_p;
249 		int reg_len;
250 		if (ddi_getlongprop(DDI_DEV_T_ANY, cdip, DDI_PROP_DONTPASS,
251 			"reg", (caddr_t)&reg_p, &reg_len) != DDI_PROP_SUCCESS)
252 			continue;
253 		cfgpa += (*reg_p) & (PCI_CONF_ADDR_MASK ^ PCI_REG_REG_M);
254 		kmem_free(reg_p, reg_len);
255 		break;
256 	}
257 
258 config:
259 	pci_iommu_config(iommu_p, ctl_val, cdip ? cfgpa : 0);
260 }
261 
262 void
263 iommu_map_pages(iommu_t *iommu_p, ddi_dma_impl_t *mp,
264 		dvma_addr_t dvma_pg, size_t npages, size_t pfn_index)
265 {
266 	int i;
267 	dvma_addr_t pg_index = dvma_pg - iommu_p->dvma_base_pg;
268 	uint64_t *tte_addr = iommu_p->iommu_tsb_vaddr + pg_index;
269 	size_t pfn_last = pfn_index + npages;
270 	uint64_t tte = PCI_GET_MP_TTE(mp->dmai_tte);
271 #ifdef DEBUG
272 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
273 #endif
274 
275 	ASSERT(pfn_last <= mp->dmai_ndvmapages);
276 
277 	DEBUG5(DBG_MAP_WIN, dip,
278 		"iommu_map_pages:%x+%x=%x npages=0x%x pfn_index=0x%x\n",
279 		(uint_t)iommu_p->dvma_base_pg, (uint_t)pg_index, dvma_pg,
280 		(uint_t)npages, (uint_t)pfn_index);
281 
282 	for (i = pfn_index; i < pfn_last; i++, pg_index++, tte_addr++) {
283 		iopfn_t pfn = PCI_GET_MP_PFN(mp, i);
284 		volatile uint64_t cur_tte = IOMMU_PTOB(pfn) | tte;
285 
286 		DEBUG3(DBG_MAP_WIN, dip, "iommu_map_pages: mp=%p pg[%x]=%x\n",
287 			mp, i, (uint_t)pfn);
288 		DEBUG3(DBG_MAP_WIN, dip,
289 			"iommu_map_pages: pg_index=%x tte=%08x.%08x\n",
290 			pg_index, HI32(cur_tte), LO32(cur_tte));
291 		ASSERT(TTE_IS_INVALID(*tte_addr));
292 		*tte_addr = cur_tte;
293 #ifdef DEBUG
294 		if (pfn == 0 && pci_warn_pp0)
295 			cmn_err(CE_WARN, "%s%d <%p> doing DMA to pp0\n",
296 				ddi_driver_name(mp->dmai_rdip),
297 				ddi_get_instance(mp->dmai_rdip), mp);
298 #endif
299 	}
300 	ASSERT(tte_addr == iommu_p->iommu_tsb_vaddr + pg_index);
301 #ifdef DEBUG
302 	if (HAS_REDZONE(mp)) {
303 		DEBUG1(DBG_MAP_WIN, dip, "iommu_map_pages: redzone pg=%x\n",
304 			pg_index);
305 		ASSERT(TTE_IS_INVALID(iommu_p->iommu_tsb_vaddr[pg_index]));
306 	}
307 #endif
308 	if (DVMA_DBG_ON(iommu_p))
309 		pci_dvma_alloc_debug(iommu_p, (char *)mp->dmai_mapping,
310 			mp->dmai_size, mp);
311 }
312 
313 /*
314  * iommu_map_window - map a dvma window into the iommu
315  *
316  * used by: pci_dma_win(), pci_dma_ctlops() - DDI_DMA_MOVWIN, DDI_DMA_NEXTWIN
317  *
318  * return value: none
319  */
320 /*ARGSUSED*/
321 void
322 iommu_map_window(iommu_t *iommu_p, ddi_dma_impl_t *mp, window_t win_no)
323 {
324 	uint32_t obj_pg0_off = mp->dmai_roffset;
325 	uint32_t win_pg0_off = win_no ? 0 : obj_pg0_off;
326 	size_t win_size = mp->dmai_winsize;
327 	size_t pfn_index = win_size * win_no;			/* temp value */
328 	size_t obj_off = win_no ? pfn_index - obj_pg0_off : 0;	/* xferred sz */
329 	dvma_addr_t dvma_pg = IOMMU_BTOP(mp->dmai_mapping);
330 	size_t res_size = mp->dmai_object.dmao_size - obj_off + win_pg0_off;
331 
332 	ASSERT(!(win_size & IOMMU_PAGE_OFFSET));
333 	if (win_no >= mp->dmai_nwin)
334 		return;
335 	if (res_size < win_size)		/* last window */
336 		win_size = res_size;		/* mp->dmai_winsize unchanged */
337 
338 	mp->dmai_mapping = IOMMU_PTOB(dvma_pg) | win_pg0_off;
339 	mp->dmai_size = win_size - win_pg0_off;	/* cur win xferrable size */
340 	mp->dmai_offset = obj_off;		/* win offset into object */
341 	pfn_index = IOMMU_BTOP(pfn_index);	/* index into pfnlist */
342 	iommu_map_pages(iommu_p, mp, dvma_pg, IOMMU_BTOPR(win_size), pfn_index);
343 }
344 
345 void
346 iommu_unmap_pages(iommu_t *iommu_p, dvma_addr_t dvma_pg, uint_t npages)
347 {
348 	dvma_addr_t pg_index = IOMMU_PAGE_INDEX(iommu_p, dvma_pg);
349 
350 	for (; npages; npages--, dvma_pg++, pg_index++) {
351 		DEBUG1(DBG_UNMAP_WIN|DBG_CONT, 0, " %x", dvma_pg);
352 		IOMMU_UNLOAD_TTE(iommu_p, pg_index);
353 
354 		if (!tm_mtlb_gc)
355 			IOMMU_PAGE_FLUSH(iommu_p, dvma_pg);
356 	}
357 }
358 
359 void
360 iommu_remap_pages(iommu_t *iommu_p, ddi_dma_impl_t *mp, dvma_addr_t dvma_pg,
361 	size_t npages, size_t pfn_index)
362 {
363 	iommu_unmap_pages(iommu_p, dvma_pg, npages);
364 	iommu_map_pages(iommu_p, mp, dvma_pg, npages, pfn_index);
365 }
366 
367 /*
368  * iommu_unmap_window
369  *
370  * This routine is called to break down the iommu mappings to a dvma window.
371  * Non partial mappings are viewed as single window mapping.
372  *
373  * used by: pci_dma_unbindhdl(), pci_dma_window(),
374  *	and pci_dma_ctlops() - DDI_DMA_FREE, DDI_DMA_MOVWIN, DDI_DMA_NEXTWIN
375  *
376  * return value: none
377  */
378 /*ARGSUSED*/
379 void
380 iommu_unmap_window(iommu_t *iommu_p, ddi_dma_impl_t *mp)
381 {
382 	dvma_addr_t dvma_pg = IOMMU_BTOP(mp->dmai_mapping);
383 	dvma_addr_t pg_index = IOMMU_PAGE_INDEX(iommu_p, dvma_pg);
384 	uint_t npages = IOMMU_BTOP(mp->dmai_winsize);
385 #ifdef DEBUG
386 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
387 #endif
388 	/*
389 	 * Invalidate each page of the mapping in the tsb and flush
390 	 * it from the tlb.
391 	 */
392 	DEBUG2(DBG_UNMAP_WIN, dip, "mp=%p %x pfns:", mp, npages);
393 	if (mp->dmai_flags & DMAI_FLAGS_CONTEXT) {
394 		dvma_context_t ctx = MP2CTX(mp);
395 		for (; npages; npages--, pg_index++) {
396 			DEBUG1(DBG_UNMAP_WIN|DBG_CONT, dip, " %x", pg_index);
397 			IOMMU_UNLOAD_TTE(iommu_p, pg_index);
398 		}
399 		DEBUG1(DBG_UNMAP_WIN|DBG_CONT, dip, " (context %x)", ctx);
400 		*iommu_p->iommu_flush_ctx_reg = ctx;
401 	} else
402 		iommu_unmap_pages(iommu_p, dvma_pg, npages);
403 
404 	DEBUG0(DBG_UNMAP_WIN|DBG_CONT, dip, "\n");
405 
406 	if (DVMA_DBG_ON(iommu_p))
407 		pci_dvma_free_debug(iommu_p, (char *)mp->dmai_mapping,
408 			mp->dmai_size, mp);
409 }
410 
411 int
412 pci_alloc_tsb(pci_t *pci_p)
413 {
414 	uint16_t tsbc;
415 
416 	if ((tsbc = iommu_tsb_alloc(pci_p->pci_id)) == IOMMU_TSB_COOKIE_NONE) {
417 		cmn_err(CE_WARN, "%s%d: Unable to allocate IOMMU TSB.",
418 		    ddi_driver_name(pci_p->pci_dip),
419 		    ddi_get_instance(pci_p->pci_dip));
420 		return (DDI_FAILURE);
421 	}
422 	pci_p->pci_tsb_cookie = tsbc;
423 	return (DDI_SUCCESS);
424 }
425 
426 void
427 pci_free_tsb(pci_t *pci_p)
428 {
429 	iommu_tsb_free(pci_p->pci_tsb_cookie);
430 }
431 
432 #if 0
433 /*
434  * The following data structure is used to map a tsb size
435  * to a tsb size configuration parameter in the iommu
436  * control register.
437  * This is a hardware table. It is here for reference only.
438  */
439 static int pci_iommu_tsb_sizes[] = {
440 	0x2000,		/* 0 - 8 mb */
441 	0x4000,		/* 1 - 16 mb */
442 	0x8000,		/* 2 - 32 mb */
443 	0x10000,	/* 3 - 64 mb */
444 	0x20000,	/* 4 - 128 mb */
445 	0x40000,	/* 5 - 256 mb */
446 	0x80000,	/* 6 - 512 mb */
447 	0x100000	/* 7 - 1 gb */
448 };
449 #endif
450 
451 uint_t
452 iommu_tsb_size_encode(uint_t tsb_bytes)
453 {
454 	uint_t i;
455 
456 	for (i = 7; i && (tsb_bytes < (0x2000 << i)); i--)
457 		/* empty */;
458 	return (i);
459 }
460 
461 /*
462  * invalidate IOMMU TLB entries through diagnostic registers.
463  */
464 static void
465 iommu_tlb_flushall(iommu_t *iommu_p)
466 {
467 	int i;
468 	uint64_t base = (uint64_t)(iommu_p->iommu_ctrl_reg) -
469 		COMMON_IOMMU_CTRL_REG_OFFSET;
470 	volatile uint64_t *tlb_tag = (volatile uint64_t *)
471 			(base + COMMON_IOMMU_TLB_TAG_DIAG_ACC_OFFSET);
472 	volatile uint64_t *tlb_data = (volatile uint64_t *)
473 			(base + COMMON_IOMMU_TLB_DATA_DIAG_ACC_OFFSET);
474 	for (i = 0; i < IOMMU_TLB_ENTRIES; i++)
475 		tlb_tag[i] = tlb_data[i] = 0ull;
476 }
477 
478 static void
479 iommu_preserve_tsb(iommu_t *iommu_p)
480 {
481 #ifdef DEBUG
482 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
483 #endif
484 	uint_t i, obp_tsb_entries, obp_tsb_size, base_pg_index;
485 	uint64_t ctl = *iommu_p->iommu_ctrl_reg;
486 	uint64_t obp_tsb_pa = *iommu_p->iommu_tsb_base_addr_reg;
487 	uint64_t *base_tte_addr;
488 
489 	DEBUG3(DBG_ATTACH, dip,
490 		"iommu_tsb_base_addr_reg=0x%08x (0x%08x.0x%08x)\n",
491 		iommu_p->iommu_tsb_base_addr_reg,
492 		(uint32_t)(*iommu_p->iommu_tsb_base_addr_reg >> 32),
493 		(uint32_t)(*iommu_p->iommu_tsb_base_addr_reg & 0xffffffff));
494 
495 	obp_tsb_size = IOMMU_CTL_TO_TSBSIZE(ctl);
496 	obp_tsb_entries = IOMMU_TSBSIZE_TO_TSBENTRIES(obp_tsb_size);
497 	base_pg_index = iommu_p->dvma_end_pg - obp_tsb_entries + 1;
498 	base_tte_addr = iommu_p->iommu_tsb_vaddr +
499 		(iommu_p->iommu_tsb_entries - obp_tsb_entries);
500 
501 	/*
502 	 * old darwin prom does not set tsb size correctly, bail out.
503 	 */
504 	if ((obp_tsb_size == IOMMU_DARWIN_BOGUS_TSBSIZE) &&
505 		(CHIP_TYPE(iommu_p->iommu_pci_p) == PCI_CHIP_SABRE))
506 			return;
507 
508 	DEBUG3(DBG_ATTACH, dip, "iommu_preserve_tsb: kernel info\n"
509 		"iommu_tsb_vaddr=%08x copy to base_tte_addr=%08x "
510 		"base_pg_index=%x\n", iommu_p->iommu_tsb_vaddr,
511 			base_tte_addr, base_pg_index);
512 
513 	DEBUG3(DBG_ATTACH | DBG_CONT, dip, "iommu_preserve_tsb: obp info "
514 		"obp_tsb_entries=0x%x obp_tsb_pa=%08x.%08x\n", obp_tsb_entries,
515 			(uint32_t)(obp_tsb_pa >> 32), (uint32_t)obp_tsb_pa);
516 
517 	for (i = 0; i < obp_tsb_entries; i++) {
518 		uint64_t tte = lddphys(obp_tsb_pa + i * 8);
519 		caddr_t va;
520 
521 		if (TTE_IS_INVALID(tte)) {
522 			DEBUG0(DBG_ATTACH | DBG_CONT, dip, ".");
523 			continue;
524 		}
525 
526 		base_tte_addr[i] = tte;
527 		DEBUG3(DBG_ATTACH | DBG_CONT, dip,
528 			"\npreserve_tsb: (%x)=%08x.%08x\n", base_tte_addr + i,
529 			(uint_t)(tte >> 32), (uint_t)(tte & 0xffffffff));
530 
531 		/*
532 		 * permanantly reserve this page from dvma address space
533 		 * resource map
534 		 */
535 
536 		va = (caddr_t)(IOMMU_PTOB(base_pg_index + i));
537 		(void) vmem_xalloc(iommu_p->iommu_dvma_map, IOMMU_PAGE_SIZE,
538 			IOMMU_PAGE_SIZE, 0, 0, va, va + IOMMU_PAGE_SIZE,
539 			VM_NOSLEEP | VM_BESTFIT | VM_PANIC);
540 	}
541 }
542