xref: /illumos-gate/usr/src/uts/sun4u/io/pci/pci_iommu.c (revision 1a1df1dbef1b5c57672433301a296dfe4311e6db)
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 /*
26  * Copyright 2012 Garrett D'Amore <garrett@damore.org>.  All rights reserved.
27  */
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 = pci_iommu_bypass_end_configure();
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 | COMMON_IOMMU_CTRL_DIAG_ENABLE |
236 	    (pci_lock_tlb ? COMMON_IOMMU_CTRL_LCK_ENABLE : 0));
237 
238 	DEBUG2(DBG_ATTACH, dip, "iommu_configure: iommu_ctl=%08x.%08x\n",
239 	    HI32(ctl_val), LO32(ctl_val));
240 	if (!pci_preserve_iommu_tsb || !(*iommu_p->iommu_tsb_base_addr_reg)) {
241 		*iommu_p->iommu_ctrl_reg = COMMON_IOMMU_CTRL_DIAG_ENABLE;
242 		iommu_tlb_flushall(iommu_p);
243 		goto config;
244 	}
245 	cdip = ddi_get_child(dip);
246 	for (; cdip; cdip = ddi_get_next_sibling(cdip)) {
247 		uint32_t *reg_p;
248 		int reg_len;
249 		if (ddi_getlongprop(DDI_DEV_T_ANY, cdip, DDI_PROP_DONTPASS,
250 		    "reg", (caddr_t)&reg_p, &reg_len) != DDI_PROP_SUCCESS)
251 			continue;
252 		cfgpa += (*reg_p) & (PCI_CONF_ADDR_MASK ^ PCI_REG_REG_M);
253 		kmem_free(reg_p, reg_len);
254 		break;
255 	}
256 
257 config:
258 	pci_iommu_config(iommu_p, ctl_val, cdip ? cfgpa : 0);
259 }
260 
261 void
262 iommu_map_pages(iommu_t *iommu_p, ddi_dma_impl_t *mp,
263 		dvma_addr_t dvma_pg, size_t npages, size_t pfn_index)
264 {
265 	int i;
266 	dvma_addr_t pg_index = dvma_pg - iommu_p->dvma_base_pg;
267 	uint64_t *tte_addr = iommu_p->iommu_tsb_vaddr + pg_index;
268 	size_t pfn_last = pfn_index + npages;
269 	uint64_t tte = PCI_GET_MP_TTE(mp->dmai_tte);
270 #ifdef DEBUG
271 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
272 #endif
273 
274 	ASSERT(pfn_last <= mp->dmai_ndvmapages);
275 
276 	DEBUG5(DBG_MAP_WIN, dip,
277 	    "iommu_map_pages:%x+%x=%x npages=0x%x pfn_index=0x%x\n",
278 	    (uint_t)iommu_p->dvma_base_pg, (uint_t)pg_index, dvma_pg,
279 	    (uint_t)npages, (uint_t)pfn_index);
280 
281 	for (i = pfn_index; i < pfn_last; i++, pg_index++, tte_addr++) {
282 		iopfn_t pfn = PCI_GET_MP_PFN(mp, i);
283 		volatile uint64_t cur_tte = IOMMU_PTOB(pfn) | tte;
284 
285 		DEBUG3(DBG_MAP_WIN, dip, "iommu_map_pages: mp=%p pg[%x]=%x\n",
286 		    mp, i, (uint_t)pfn);
287 		DEBUG3(DBG_MAP_WIN, dip,
288 		    "iommu_map_pages: pg_index=%x tte=%08x.%08x\n",
289 		    pg_index, HI32(cur_tte), LO32(cur_tte));
290 		ASSERT(TTE_IS_INVALID(*tte_addr));
291 		*tte_addr = cur_tte;
292 #ifdef DEBUG
293 		if (pfn == 0 && pci_warn_pp0)
294 			cmn_err(CE_WARN, "%s%d <%p> doing DMA to pp0\n",
295 			    ddi_driver_name(mp->dmai_rdip),
296 			    ddi_get_instance(mp->dmai_rdip), mp);
297 #endif
298 	}
299 	ASSERT(tte_addr == iommu_p->iommu_tsb_vaddr + pg_index);
300 #ifdef DEBUG
301 	if (HAS_REDZONE(mp)) {
302 		DEBUG1(DBG_MAP_WIN, dip, "iommu_map_pages: redzone pg=%x\n",
303 		    pg_index);
304 		ASSERT(TTE_IS_INVALID(iommu_p->iommu_tsb_vaddr[pg_index]));
305 	}
306 #endif
307 	if (DVMA_DBG_ON(iommu_p))
308 		pci_dvma_alloc_debug(iommu_p, (char *)mp->dmai_mapping,
309 		    mp->dmai_size, mp);
310 }
311 
312 /*
313  * iommu_map_window - map a dvma window into the iommu
314  *
315  * used by: pci_dma_win(), pci_dma_ctlops() - DDI_DMA_MOVWIN
316  *
317  * return value: none
318  */
319 /*ARGSUSED*/
320 void
321 iommu_map_window(iommu_t *iommu_p, ddi_dma_impl_t *mp, window_t win_no)
322 {
323 	uint32_t obj_pg0_off = mp->dmai_roffset;
324 	uint32_t win_pg0_off = win_no ? 0 : obj_pg0_off;
325 	size_t win_size = mp->dmai_winsize;
326 	size_t pfn_index = win_size * win_no;			/* temp value */
327 	size_t obj_off = win_no ? pfn_index - obj_pg0_off : 0;	/* xferred sz */
328 	dvma_addr_t dvma_pg = IOMMU_BTOP(mp->dmai_mapping);
329 	size_t res_size = mp->dmai_object.dmao_size - obj_off + win_pg0_off;
330 
331 	ASSERT(!(win_size & IOMMU_PAGE_OFFSET));
332 	if (win_no >= mp->dmai_nwin)
333 		return;
334 	if (res_size < win_size)		/* last window */
335 		win_size = res_size;		/* mp->dmai_winsize unchanged */
336 
337 	mp->dmai_mapping = IOMMU_PTOB(dvma_pg) | win_pg0_off;
338 	mp->dmai_size = win_size - win_pg0_off;	/* cur win xferrable size */
339 	mp->dmai_offset = obj_off;		/* win offset into object */
340 	pfn_index = IOMMU_BTOP(pfn_index);	/* index into pfnlist */
341 	iommu_map_pages(iommu_p, mp, dvma_pg, IOMMU_BTOPR(win_size), pfn_index);
342 }
343 
344 void
345 iommu_unmap_pages(iommu_t *iommu_p, dvma_addr_t dvma_pg, uint_t npages)
346 {
347 	dvma_addr_t pg_index = IOMMU_PAGE_INDEX(iommu_p, dvma_pg);
348 
349 	for (; npages; npages--, dvma_pg++, pg_index++) {
350 		DEBUG1(DBG_UNMAP_WIN|DBG_CONT, 0, " %x", dvma_pg);
351 		IOMMU_UNLOAD_TTE(iommu_p, pg_index);
352 
353 		if (!tm_mtlb_gc)
354 			IOMMU_PAGE_FLUSH(iommu_p, dvma_pg);
355 	}
356 }
357 
358 void
359 iommu_remap_pages(iommu_t *iommu_p, ddi_dma_impl_t *mp, dvma_addr_t dvma_pg,
360 	size_t npages, size_t pfn_index)
361 {
362 	iommu_unmap_pages(iommu_p, dvma_pg, npages);
363 	iommu_map_pages(iommu_p, mp, dvma_pg, npages, pfn_index);
364 }
365 
366 /*
367  * iommu_unmap_window
368  *
369  * This routine is called to break down the iommu mappings to a dvma window.
370  * Non partial mappings are viewed as single window mapping.
371  *
372  * used by: pci_dma_unbindhdl(), pci_dma_window(),
373  *	and pci_dma_ctlops() - DDI_DMA_FREE, DDI_DMA_MOVWIN, DDI_DMA_NEXTWIN
374  *
375  * return value: none
376  */
377 /*ARGSUSED*/
378 void
379 iommu_unmap_window(iommu_t *iommu_p, ddi_dma_impl_t *mp)
380 {
381 	dvma_addr_t dvma_pg = IOMMU_BTOP(mp->dmai_mapping);
382 	dvma_addr_t pg_index = IOMMU_PAGE_INDEX(iommu_p, dvma_pg);
383 	uint_t npages = IOMMU_BTOP(mp->dmai_winsize);
384 #ifdef DEBUG
385 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
386 #endif
387 	/*
388 	 * Invalidate each page of the mapping in the tsb and flush
389 	 * it from the tlb.
390 	 */
391 	DEBUG2(DBG_UNMAP_WIN, dip, "mp=%p %x pfns:", mp, npages);
392 	if (mp->dmai_flags & DMAI_FLAGS_CONTEXT) {
393 		dvma_context_t ctx = MP2CTX(mp);
394 		for (; npages; npages--, pg_index++) {
395 			DEBUG1(DBG_UNMAP_WIN|DBG_CONT, dip, " %x", pg_index);
396 			IOMMU_UNLOAD_TTE(iommu_p, pg_index);
397 		}
398 		DEBUG1(DBG_UNMAP_WIN|DBG_CONT, dip, " (context %x)", ctx);
399 		*iommu_p->iommu_flush_ctx_reg = ctx;
400 	} else
401 		iommu_unmap_pages(iommu_p, dvma_pg, npages);
402 
403 	DEBUG0(DBG_UNMAP_WIN|DBG_CONT, dip, "\n");
404 
405 	if (DVMA_DBG_ON(iommu_p))
406 		pci_dvma_free_debug(iommu_p, (char *)mp->dmai_mapping,
407 		    mp->dmai_size, mp);
408 }
409 
410 int
411 pci_alloc_tsb(pci_t *pci_p)
412 {
413 	uint16_t tsbc;
414 
415 	if ((tsbc = iommu_tsb_alloc(pci_p->pci_id)) == IOMMU_TSB_COOKIE_NONE) {
416 		cmn_err(CE_WARN, "%s%d: Unable to allocate IOMMU TSB.",
417 		    ddi_driver_name(pci_p->pci_dip),
418 		    ddi_get_instance(pci_p->pci_dip));
419 		return (DDI_FAILURE);
420 	}
421 	pci_p->pci_tsb_cookie = tsbc;
422 	return (DDI_SUCCESS);
423 }
424 
425 void
426 pci_free_tsb(pci_t *pci_p)
427 {
428 	iommu_tsb_free(pci_p->pci_tsb_cookie);
429 }
430 
431 #if 0
432 /*
433  * The following data structure is used to map a tsb size
434  * to a tsb size configuration parameter in the iommu
435  * control register.
436  * This is a hardware table. It is here for reference only.
437  */
438 static int pci_iommu_tsb_sizes[] = {
439 	0x2000,		/* 0 - 8 mb */
440 	0x4000,		/* 1 - 16 mb */
441 	0x8000,		/* 2 - 32 mb */
442 	0x10000,	/* 3 - 64 mb */
443 	0x20000,	/* 4 - 128 mb */
444 	0x40000,	/* 5 - 256 mb */
445 	0x80000,	/* 6 - 512 mb */
446 	0x100000	/* 7 - 1 gb */
447 };
448 #endif
449 
450 uint_t
451 iommu_tsb_size_encode(uint_t tsb_bytes)
452 {
453 	uint_t i;
454 
455 	for (i = 7; i && (tsb_bytes < (0x2000 << i)); i--)
456 		/* empty */;
457 	return (i);
458 }
459 
460 /*
461  * invalidate IOMMU TLB entries through diagnostic registers.
462  */
463 static void
464 iommu_tlb_flushall(iommu_t *iommu_p)
465 {
466 	int i;
467 	uint64_t base = (uint64_t)(iommu_p->iommu_ctrl_reg) -
468 	    COMMON_IOMMU_CTRL_REG_OFFSET;
469 	volatile uint64_t *tlb_tag = (volatile uint64_t *)
470 	    (base + COMMON_IOMMU_TLB_TAG_DIAG_ACC_OFFSET);
471 	volatile uint64_t *tlb_data = (volatile uint64_t *)
472 	    (base + COMMON_IOMMU_TLB_DATA_DIAG_ACC_OFFSET);
473 	for (i = 0; i < IOMMU_TLB_ENTRIES; i++)
474 		tlb_tag[i] = tlb_data[i] = 0ull;
475 }
476 
477 static void
478 iommu_preserve_tsb(iommu_t *iommu_p)
479 {
480 #ifdef DEBUG
481 	dev_info_t *dip = iommu_p->iommu_pci_p->pci_dip;
482 #endif
483 	uint_t i, obp_tsb_entries, obp_tsb_size, base_pg_index;
484 	uint64_t ctl = *iommu_p->iommu_ctrl_reg;
485 	uint64_t obp_tsb_pa = *iommu_p->iommu_tsb_base_addr_reg;
486 	uint64_t *base_tte_addr;
487 
488 	DEBUG3(DBG_ATTACH, dip,
489 	    "iommu_tsb_base_addr_reg=0x%08x (0x%08x.0x%08x)\n",
490 	    iommu_p->iommu_tsb_base_addr_reg,
491 	    (uint32_t)(*iommu_p->iommu_tsb_base_addr_reg >> 32),
492 	    (uint32_t)(*iommu_p->iommu_tsb_base_addr_reg & 0xffffffff));
493 
494 	obp_tsb_size = IOMMU_CTL_TO_TSBSIZE(ctl);
495 	obp_tsb_entries = IOMMU_TSBSIZE_TO_TSBENTRIES(obp_tsb_size);
496 	base_pg_index = iommu_p->dvma_end_pg - obp_tsb_entries + 1;
497 	base_tte_addr = iommu_p->iommu_tsb_vaddr +
498 	    (iommu_p->iommu_tsb_entries - obp_tsb_entries);
499 
500 	/*
501 	 * old darwin prom does not set tsb size correctly, bail out.
502 	 */
503 	if ((obp_tsb_size == IOMMU_DARWIN_BOGUS_TSBSIZE) &&
504 	    (CHIP_TYPE(iommu_p->iommu_pci_p) == PCI_CHIP_SABRE))
505 		return;
506 
507 	DEBUG3(DBG_ATTACH, dip, "iommu_preserve_tsb: kernel info\n"
508 	    "iommu_tsb_vaddr=%08x copy to base_tte_addr=%08x "
509 	    "base_pg_index=%x\n", iommu_p->iommu_tsb_vaddr,
510 	    base_tte_addr, base_pg_index);
511 
512 	DEBUG3(DBG_ATTACH | DBG_CONT, dip, "iommu_preserve_tsb: obp info "
513 	    "obp_tsb_entries=0x%x obp_tsb_pa=%08x.%08x\n", obp_tsb_entries,
514 	    (uint32_t)(obp_tsb_pa >> 32), (uint32_t)obp_tsb_pa);
515 
516 	for (i = 0; i < obp_tsb_entries; i++) {
517 		uint64_t tte = lddphys(obp_tsb_pa + i * 8);
518 		caddr_t va;
519 
520 		if (TTE_IS_INVALID(tte)) {
521 			DEBUG0(DBG_ATTACH | DBG_CONT, dip, ".");
522 			continue;
523 		}
524 
525 		base_tte_addr[i] = tte;
526 		DEBUG3(DBG_ATTACH | DBG_CONT, dip,
527 		    "\npreserve_tsb: (%x)=%08x.%08x\n", base_tte_addr + i,
528 		    (uint_t)(tte >> 32), (uint_t)(tte & 0xffffffff));
529 
530 		/*
531 		 * permanantly reserve this page from dvma address space
532 		 * resource map
533 		 */
534 
535 		va = (caddr_t)(IOMMU_PTOB(base_pg_index + i));
536 		(void) vmem_xalloc(iommu_p->iommu_dvma_map, IOMMU_PAGE_SIZE,
537 		    IOMMU_PAGE_SIZE, 0, 0, va, va + IOMMU_PAGE_SIZE,
538 		    VM_NOSLEEP | VM_BESTFIT | VM_PANIC);
539 	}
540 }
541