xref: /titanic_51/usr/src/uts/i86pc/os/lgrpplat.c (revision c2785286330b58810071fc24f6ca69f401682dff)
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 2008 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 /*
31  * LOCALITY GROUP (LGROUP) PLATFORM SUPPORT FOR X86/AMD64 PLATFORMS
32  * ================================================================
33  * Multiprocessor AMD and Intel systems may have Non Uniform Memory Access
34  * (NUMA).  A NUMA machine consists of one or more "nodes" that each consist of
35  * one or more CPUs and some local memory.  The CPUs in each node can access
36  * the memory in the other nodes but at a higher latency than accessing their
37  * local memory.  Typically, a system with only one node has Uniform Memory
38  * Access (UMA), but it may be possible to have a one node system that has
39  * some global memory outside of the node which is higher latency.
40  *
41  * Module Description
42  * ------------------
43  * This module provides a platform interface for determining which CPUs and
44  * which memory (and how much) are in a NUMA node and how far each node is from
45  * each other.  The interface is used by the Virtual Memory (VM) system and the
46  * common lgroup framework.  The VM system uses the plat_*() routines to fill
47  * in its memory node (memnode) array with the physical address range spanned
48  * by each NUMA node to know which memory belongs to which node, so it can
49  * build and manage a physical page free list for each NUMA node and allocate
50  * local memory from each node as needed.  The common lgroup framework uses the
51  * exported lgrp_plat_*() routines to figure out which CPUs and memory belong
52  * to each node (leaf lgroup) and how far each node is from each other, so it
53  * can build the latency (lgroup) topology for the machine in order to optimize
54  * for locality.  Also, an lgroup platform handle instead of lgroups are used
55  * in the interface with this module, so this module shouldn't need to know
56  * anything about lgroups.  Instead, it just needs to know which CPUs, memory,
57  * etc. are in each NUMA node, how far each node is from each other, and to use
58  * a unique lgroup platform handle to refer to each node through the interface.
59  *
60  * Determining NUMA Configuration
61  * ------------------------------
62  * By default, this module will try to determine the NUMA configuration of the
63  * machine by reading the ACPI System Resource Affinity Table (SRAT) and System
64  * Locality Information Table (SLIT).  The SRAT contains info to tell which
65  * CPUs and memory are local to a given proximity domain (NUMA node).  The SLIT
66  * is a matrix that gives the distance between each system locality (which is
67  * a NUMA node and should correspond to proximity domains in the SRAT).  For
68  * more details on the SRAT and SLIT, please refer to an ACPI 3.0 or newer
69  * specification.
70  *
71  * If the SRAT doesn't exist on a system with AMD Opteron processors, we
72  * examine registers in PCI configuration space to determine how many nodes are
73  * in the system and which CPUs and memory are in each node.
74  * do while booting the kernel.
75  *
76  * NOTE: Using these PCI configuration space registers to determine this
77  *       locality info is not guaranteed to work or be compatible across all
78  *	 Opteron processor families.
79  *
80  * If the SLIT does not exist or look right, the kernel will probe to determine
81  * the distance between nodes as long as the NUMA CPU and memory configuration
82  * has been determined (see lgrp_plat_probe() for details).
83  *
84  * Data Structures
85  * ---------------
86  * The main data structures used by this code are the following:
87  *
88  * - lgrp_plat_cpu_node[]		CPU to node ID mapping table indexed by
89  *					CPU ID (only used for SRAT)
90  *
91  * - lgrp_plat_lat_stats.latencies[][]	Table of latencies between same and
92  *					different nodes indexed by node ID
93  *
94  * - lgrp_plat_node_cnt			Number of NUMA nodes in system
95  *
96  * - lgrp_plat_node_domain[]		Node ID to proximity domain ID mapping
97  *					table indexed by node ID (only used
98  *					for SRAT)
99  *
100  * - lgrp_plat_node_memory[]		Table with physical address range for
101  *					each node indexed by node ID
102  *
103  * The code is implemented to make the following always be true:
104  *
105  *	lgroup platform handle == node ID == memnode ID
106  *
107  * Moreover, it allows for the proximity domain ID to be equal to all of the
108  * above as long as the proximity domains IDs are numbered from 0 to <number of
109  * nodes - 1>.  This is done by hashing each proximity domain ID into the range
110  * from 0 to <number of nodes - 1>.  Then proximity ID N will hash into node ID
111  * N and proximity domain ID N will be entered into lgrp_plat_node_domain[N]
112  * and be assigned node ID N.  If the proximity domain IDs aren't numbered
113  * from 0 to <number of nodes - 1>, then hashing the proximity domain IDs into
114  * lgrp_plat_node_domain[] will still work for assigning proximity domain IDs
115  * to node IDs.  However, the proximity domain IDs may not map to the
116  * equivalent node ID since we want to keep the node IDs numbered from 0 to
117  * <number of nodes - 1> to minimize cost of searching and potentially space.
118  */
119 
120 
121 #include <sys/archsystm.h>	/* for {in,out}{b,w,l}() */
122 #include <sys/bootconf.h>
123 #include <sys/cmn_err.h>
124 #include <sys/controlregs.h>
125 #include <sys/cpupart.h>
126 #include <sys/cpuvar.h>
127 #include <sys/lgrp.h>
128 #include <sys/machsystm.h>
129 #include <sys/memlist.h>
130 #include <sys/memnode.h>
131 #include <sys/mman.h>
132 #include <sys/pci_cfgspace.h>
133 #include <sys/pci_impl.h>
134 #include <sys/param.h>
135 #include <sys/pghw.h>
136 #include <sys/promif.h>		/* for prom_printf() */
137 #include <sys/sysmacros.h>
138 #include <sys/systm.h>
139 #include <sys/thread.h>
140 #include <sys/types.h>
141 #include <sys/var.h>
142 #include <sys/x86_archext.h>	/* for x86_feature and X86_AMD */
143 #include <vm/hat_i86.h>
144 #include <vm/seg_kmem.h>
145 #include <vm/vm_dep.h>
146 
147 #include "acpi_fw.h"		/* for SRAT and SLIT */
148 
149 
150 #define	MAX_NODES		8
151 #define	NLGRP			(MAX_NODES * (MAX_NODES - 1) + 1)
152 
153 /*
154  * Constants for configuring probing
155  */
156 #define	LGRP_PLAT_PROBE_NROUNDS		64	/* default laps for probing */
157 #define	LGRP_PLAT_PROBE_NSAMPLES	1	/* default samples to take */
158 #define	LGRP_PLAT_PROBE_NREADS		256	/* number of vendor ID reads */
159 
160 /*
161  * Flags for probing
162  */
163 #define	LGRP_PLAT_PROBE_ENABLE		0x1	/* enable probing */
164 #define	LGRP_PLAT_PROBE_PGCPY		0x2	/* probe using page copy */
165 #define	LGRP_PLAT_PROBE_VENDOR		0x4	/* probe vendor ID register */
166 
167 /*
168  * Hash proximity domain ID into node to domain mapping table using to minimize
169  * span of entries used
170  */
171 #define	NODE_DOMAIN_HASH(domain, node_cnt)	((domain) % node_cnt)
172 
173 
174 /*
175  * CPU to node ID mapping structure (only used with SRAT)
176  */
177 typedef	struct cpu_node_map {
178 	int		exists;
179 	uint_t		node;
180 	uint32_t	apicid;
181 	uint32_t	prox_domain;
182 } cpu_node_map_t;
183 
184 /*
185  * Latency statistics
186  */
187 typedef struct lgrp_plat_latency_stats {
188 	hrtime_t	latencies[MAX_NODES][MAX_NODES];
189 	hrtime_t	latency_max;
190 	hrtime_t	latency_min;
191 } lgrp_plat_latency_stats_t;
192 
193 /*
194  * Memory configuration for probing
195  */
196 typedef struct lgrp_plat_probe_mem_config {
197 	size_t	probe_memsize;		/* how much memory to probe per node */
198 	caddr_t	probe_va[MAX_NODES];	/* where memory mapped for probing */
199 	pfn_t	probe_pfn[MAX_NODES];	/* physical pages to map for probing */
200 } lgrp_plat_probe_mem_config_t;
201 
202 /*
203  * Statistics kept for probing
204  */
205 typedef struct lgrp_plat_probe_stats {
206 	hrtime_t	flush_cost;
207 	hrtime_t	probe_cost;
208 	hrtime_t	probe_cost_total;
209 	hrtime_t	probe_error_code;
210 	hrtime_t	probe_errors[MAX_NODES][MAX_NODES];
211 	int		probe_suspect[MAX_NODES][MAX_NODES];
212 	hrtime_t	probe_max[MAX_NODES][MAX_NODES];
213 	hrtime_t	probe_min[MAX_NODES][MAX_NODES];
214 } lgrp_plat_probe_stats_t;
215 
216 /*
217  * Node to proximity domain ID mapping structure (only used with SRAT)
218  */
219 typedef	struct node_domain_map {
220 	int		exists;
221 	uint32_t	prox_domain;
222 } node_domain_map_t;
223 
224 /*
225  * Node ID and starting and ending page for physical memory in node
226  */
227 typedef	struct node_phys_addr_map {
228 	pfn_t		start;
229 	pfn_t		end;
230 	int		exists;
231 	uint32_t	prox_domain;
232 } node_phys_addr_map_t;
233 
234 /*
235  * Number of CPUs for which we got APIC IDs
236  */
237 static int				lgrp_plat_apic_ncpus = 0;
238 
239 /*
240  * CPU to node ID mapping table (only used for SRAT)
241  */
242 static cpu_node_map_t			lgrp_plat_cpu_node[NCPU];
243 
244 /*
245  * Latency statistics
246  */
247 lgrp_plat_latency_stats_t		lgrp_plat_lat_stats;
248 
249 /*
250  * Whether memory is interleaved across nodes causing MPO to be disabled
251  */
252 static int				lgrp_plat_mem_intrlv = 0;
253 
254 /*
255  * Node ID to proximity domain ID mapping table (only used for SRAT)
256  */
257 static node_domain_map_t		lgrp_plat_node_domain[MAX_NODES];
258 
259 /*
260  * Physical address range for memory in each node
261  */
262 static node_phys_addr_map_t		lgrp_plat_node_memory[MAX_NODES];
263 
264 /*
265  * Statistics gotten from probing
266  */
267 static lgrp_plat_probe_stats_t		lgrp_plat_probe_stats;
268 
269 /*
270  * Memory configuration for probing
271  */
272 static lgrp_plat_probe_mem_config_t	lgrp_plat_probe_mem_config;
273 
274 /*
275  * Error code from processing ACPI SRAT
276  */
277 static int				lgrp_plat_srat_error = 0;
278 
279 /*
280  * Error code from processing ACPI SLIT
281  */
282 static int				lgrp_plat_slit_error = 0;
283 
284 /*
285  * Allocate lgroup array statically
286  */
287 static lgrp_t				lgrp_space[NLGRP];
288 static int				nlgrps_alloc;
289 
290 
291 /*
292  * Number of nodes in system
293  */
294 uint_t			lgrp_plat_node_cnt = 1;
295 
296 /*
297  * Configuration Parameters for Probing
298  * - lgrp_plat_probe_flags	Flags to specify enabling probing, probe
299  *				operation, etc.
300  * - lgrp_plat_probe_nrounds	How many rounds of probing to do
301  * - lgrp_plat_probe_nsamples	Number of samples to take when probing each
302  *				node
303  * - lgrp_plat_probe_nreads	Number of times to read vendor ID from
304  *				Northbridge for each probe
305  */
306 uint_t			lgrp_plat_probe_flags = 0;
307 int			lgrp_plat_probe_nrounds = LGRP_PLAT_PROBE_NROUNDS;
308 int			lgrp_plat_probe_nsamples = LGRP_PLAT_PROBE_NSAMPLES;
309 int			lgrp_plat_probe_nreads = LGRP_PLAT_PROBE_NREADS;
310 
311 /*
312  * Enable use of ACPI System Resource Affinity Table (SRAT) and System
313  * Locality Information Table (SLIT)
314  */
315 int			lgrp_plat_srat_enable = 1;
316 int			lgrp_plat_slit_enable = 1;
317 
318 /*
319  * Static array to hold lgroup statistics
320  */
321 struct lgrp_stats	lgrp_stats[NLGRP];
322 
323 
324 /*
325  * Forward declarations of platform interface routines
326  */
327 void		plat_build_mem_nodes(struct memlist *list);
328 
329 int		plat_lgrphand_to_mem_node(lgrp_handle_t hand);
330 
331 lgrp_handle_t	plat_mem_node_to_lgrphand(int mnode);
332 
333 int		plat_mnode_xcheck(pfn_t pfncnt);
334 
335 int		plat_pfn_to_mem_node(pfn_t pfn);
336 
337 /*
338  * Forward declarations of lgroup platform interface routines
339  */
340 lgrp_t		*lgrp_plat_alloc(lgrp_id_t lgrpid);
341 
342 void		lgrp_plat_config(lgrp_config_flag_t flag, uintptr_t arg);
343 
344 lgrp_handle_t	lgrp_plat_cpu_to_hand(processorid_t id);
345 
346 void		lgrp_plat_init(void);
347 
348 int		lgrp_plat_latency(lgrp_handle_t from, lgrp_handle_t to);
349 
350 void		lgrp_plat_main_init(void);
351 
352 int		lgrp_plat_max_lgrps(void);
353 
354 pgcnt_t		lgrp_plat_mem_size(lgrp_handle_t plathand,
355     lgrp_mem_query_t query);
356 
357 lgrp_handle_t	lgrp_plat_pfn_to_hand(pfn_t pfn);
358 
359 void		lgrp_plat_probe(void);
360 
361 lgrp_handle_t	lgrp_plat_root_hand(void);
362 
363 
364 /*
365  * Forward declarations of local routines
366  */
367 static int	is_opteron(void);
368 
369 static int	lgrp_plat_cpu_node_update(node_domain_map_t *node_domain,
370     int node_cnt, cpu_node_map_t *cpu_node, int nentries, uint32_t apicid,
371     uint32_t domain);
372 
373 static int	lgrp_plat_cpu_to_node(cpu_t *cp, cpu_node_map_t *cpu_node);
374 
375 static int	lgrp_plat_domain_to_node(node_domain_map_t *node_domain,
376     int node_cnt, uint32_t domain);
377 
378 static void	lgrp_plat_latency_adjust(node_phys_addr_map_t *node_memory,
379     lgrp_plat_latency_stats_t *lat_stats,
380     lgrp_plat_probe_stats_t *probe_stats);
381 
382 static int	lgrp_plat_latency_verify(node_phys_addr_map_t *node_memory,
383     lgrp_plat_latency_stats_t *lat_stats);
384 
385 static pgcnt_t	lgrp_plat_mem_size_default(lgrp_handle_t, lgrp_mem_query_t);
386 
387 static int	lgrp_plat_node_domain_update(node_domain_map_t *node_domain,
388     int node_cnt, uint32_t domain);
389 
390 static int	lgrp_plat_node_memory_update(node_domain_map_t *node_domain,
391     int node_cnt, node_phys_addr_map_t *node_memory, uint64_t start,
392     uint64_t end, uint32_t domain);
393 
394 static hrtime_t	lgrp_plat_probe_time(int to, cpu_node_map_t *cpu_node,
395     lgrp_plat_probe_mem_config_t *probe_mem_config,
396     lgrp_plat_latency_stats_t *lat_stats,
397     lgrp_plat_probe_stats_t *probe_stats);
398 
399 static int	lgrp_plat_process_cpu_apicids(cpu_node_map_t *cpu_node);
400 
401 static int	lgrp_plat_process_slit(struct slit *tp, uint_t node_cnt,
402     node_phys_addr_map_t *node_memory, lgrp_plat_latency_stats_t *lat_stats);
403 
404 static int	lgrp_plat_process_srat(struct srat *tp,
405     node_domain_map_t *node_domain, cpu_node_map_t *cpu_node, int cpu_count,
406     node_phys_addr_map_t *node_memory);
407 
408 static int	lgrp_plat_srat_domains(struct srat *tp);
409 
410 static void	lgrp_plat_2level_setup(node_phys_addr_map_t *node_memory,
411     lgrp_plat_latency_stats_t *lat_stats);
412 
413 static void	opt_get_numa_config(uint_t *node_cnt, int *mem_intrlv,
414     node_phys_addr_map_t *node_memory);
415 
416 static hrtime_t	opt_probe_vendor(int dest_node, int nreads);
417 
418 
419 /*
420  * PLATFORM INTERFACE ROUTINES
421  */
422 
423 /*
424  * Configure memory nodes for machines with more than one node (ie NUMA)
425  */
426 void
427 plat_build_mem_nodes(struct memlist *list)
428 {
429 	pfn_t		cur_start;	/* start addr of subrange */
430 	pfn_t		cur_end;	/* end addr of subrange */
431 	pfn_t		start;		/* start addr of whole range */
432 	pfn_t		end;		/* end addr of whole range */
433 
434 	/*
435 	 * Boot install lists are arranged <addr, len>, ...
436 	 */
437 	while (list) {
438 		int	node;
439 
440 		start = list->address >> PAGESHIFT;
441 		end = (list->address + list->size - 1) >> PAGESHIFT;
442 
443 		if (start > physmax) {
444 			list = list->next;
445 			continue;
446 		}
447 		if (end > physmax)
448 			end = physmax;
449 
450 		/*
451 		 * When there is only one memnode, just add memory to memnode
452 		 */
453 		if (max_mem_nodes == 1) {
454 			mem_node_add_slice(start, end);
455 			list = list->next;
456 			continue;
457 		}
458 
459 		/*
460 		 * mem_node_add_slice() expects to get a memory range that
461 		 * is within one memnode, so need to split any memory range
462 		 * that spans multiple memnodes into subranges that are each
463 		 * contained within one memnode when feeding them to
464 		 * mem_node_add_slice()
465 		 */
466 		cur_start = start;
467 		do {
468 			node = plat_pfn_to_mem_node(cur_start);
469 
470 			/*
471 			 * Panic if DRAM address map registers or SRAT say
472 			 * memory in node doesn't exist or address from
473 			 * boot installed memory list entry isn't in this node.
474 			 * This shouldn't happen and rest of code can't deal
475 			 * with this if it does.
476 			 */
477 			if (node < 0 || node >= lgrp_plat_node_cnt ||
478 			    !lgrp_plat_node_memory[node].exists ||
479 			    cur_start < lgrp_plat_node_memory[node].start ||
480 			    cur_start > lgrp_plat_node_memory[node].end) {
481 				cmn_err(CE_PANIC, "Don't know which memnode "
482 				    "to add installed memory address 0x%lx\n",
483 				    cur_start);
484 			}
485 
486 			/*
487 			 * End of current subrange should not span memnodes
488 			 */
489 			cur_end = end;
490 			if (lgrp_plat_node_memory[node].exists &&
491 			    cur_end > lgrp_plat_node_memory[node].end)
492 				cur_end = lgrp_plat_node_memory[node].end;
493 
494 			mem_node_add_slice(cur_start, cur_end);
495 
496 			/*
497 			 * Next subrange starts after end of current one
498 			 */
499 			cur_start = cur_end + 1;
500 		} while (cur_end < end);
501 
502 		list = list->next;
503 	}
504 	mem_node_physalign = 0;
505 	mem_node_pfn_shift = 0;
506 }
507 
508 
509 int
510 plat_lgrphand_to_mem_node(lgrp_handle_t hand)
511 {
512 	if (max_mem_nodes == 1)
513 		return (0);
514 
515 	return ((int)hand);
516 }
517 
518 
519 /*
520  * plat_mnode_xcheck: checks the node memory ranges to see if there is a pfncnt
521  * range of pages aligned on pfncnt that crosses an node boundary. Returns 1 if
522  * a crossing is found and returns 0 otherwise.
523  */
524 int
525 plat_mnode_xcheck(pfn_t pfncnt)
526 {
527 	int	node, prevnode = -1, basenode;
528 	pfn_t	ea, sa;
529 
530 	for (node = 0; node < lgrp_plat_node_cnt; node++) {
531 
532 		if (lgrp_plat_node_memory[node].exists == 0)
533 			continue;
534 
535 		if (prevnode == -1) {
536 			prevnode = node;
537 			basenode = node;
538 			continue;
539 		}
540 
541 		/* assume x86 node pfn ranges are in increasing order */
542 		ASSERT(lgrp_plat_node_memory[node].start >
543 		    lgrp_plat_node_memory[prevnode].end);
544 
545 		/*
546 		 * continue if the starting address of node is not contiguous
547 		 * with the previous node.
548 		 */
549 
550 		if (lgrp_plat_node_memory[node].start !=
551 		    (lgrp_plat_node_memory[prevnode].end + 1)) {
552 			basenode = node;
553 			prevnode = node;
554 			continue;
555 		}
556 
557 		/* check if the starting address of node is pfncnt aligned */
558 		if ((lgrp_plat_node_memory[node].start & (pfncnt - 1)) != 0) {
559 
560 			/*
561 			 * at this point, node starts at an unaligned boundary
562 			 * and is contiguous with the previous node(s) to
563 			 * basenode. Check if there is an aligned contiguous
564 			 * range of length pfncnt that crosses this boundary.
565 			 */
566 
567 			sa = P2ALIGN(lgrp_plat_node_memory[prevnode].end,
568 			    pfncnt);
569 			ea = P2ROUNDUP((lgrp_plat_node_memory[node].start),
570 			    pfncnt);
571 
572 			ASSERT((ea - sa) == pfncnt);
573 			if (sa >= lgrp_plat_node_memory[basenode].start &&
574 			    ea <= (lgrp_plat_node_memory[node].end + 1))
575 				return (1);
576 		}
577 		prevnode = node;
578 	}
579 	return (0);
580 }
581 
582 
583 lgrp_handle_t
584 plat_mem_node_to_lgrphand(int mnode)
585 {
586 	if (max_mem_nodes == 1)
587 		return (LGRP_DEFAULT_HANDLE);
588 
589 	return ((lgrp_handle_t)mnode);
590 }
591 
592 
593 int
594 plat_pfn_to_mem_node(pfn_t pfn)
595 {
596 	int	node;
597 
598 	if (max_mem_nodes == 1)
599 		return (0);
600 
601 	for (node = 0; node < lgrp_plat_node_cnt; node++) {
602 		/*
603 		 * Skip nodes with no memory
604 		 */
605 		if (!lgrp_plat_node_memory[node].exists)
606 			continue;
607 
608 		if (pfn >= lgrp_plat_node_memory[node].start &&
609 		    pfn <= lgrp_plat_node_memory[node].end)
610 			return (node);
611 	}
612 
613 	/*
614 	 * Didn't find memnode where this PFN lives which should never happen
615 	 */
616 	ASSERT(node < lgrp_plat_node_cnt);
617 	return (-1);
618 }
619 
620 
621 /*
622  * LGROUP PLATFORM INTERFACE ROUTINES
623  */
624 
625 /*
626  * Allocate additional space for an lgroup.
627  */
628 /* ARGSUSED */
629 lgrp_t *
630 lgrp_plat_alloc(lgrp_id_t lgrpid)
631 {
632 	lgrp_t *lgrp;
633 
634 	lgrp = &lgrp_space[nlgrps_alloc++];
635 	if (lgrpid >= NLGRP || nlgrps_alloc > NLGRP)
636 		return (NULL);
637 	return (lgrp);
638 }
639 
640 
641 /*
642  * Platform handling for (re)configuration changes
643  */
644 /* ARGSUSED */
645 void
646 lgrp_plat_config(lgrp_config_flag_t flag, uintptr_t arg)
647 {
648 }
649 
650 
651 /*
652  * Return the platform handle for the lgroup containing the given CPU
653  */
654 /* ARGSUSED */
655 lgrp_handle_t
656 lgrp_plat_cpu_to_hand(processorid_t id)
657 {
658 	lgrp_handle_t	hand;
659 
660 	if (lgrp_plat_node_cnt == 1)
661 		return (LGRP_DEFAULT_HANDLE);
662 
663 	hand = (lgrp_handle_t)lgrp_plat_cpu_to_node(cpu[id],
664 	    lgrp_plat_cpu_node);
665 
666 	ASSERT(hand != (lgrp_handle_t)-1);
667 	if (hand == (lgrp_handle_t)-1)
668 		return (LGRP_NULL_HANDLE);
669 
670 	return (hand);
671 }
672 
673 
674 /*
675  * Platform-specific initialization of lgroups
676  */
677 void
678 lgrp_plat_init(void)
679 {
680 #if defined(__xpv)
681 	/*
682 	 * XXPV	For now, the hypervisor treats all memory equally.
683 	 */
684 	lgrp_plat_node_cnt = max_mem_nodes = 1;
685 #else	/* __xpv */
686 	uint_t	probe_op;
687 
688 	/*
689 	 * Initialize as a UMA machine
690 	 */
691 	if (lgrp_topo_ht_limit() == 1) {
692 		lgrp_plat_node_cnt = max_mem_nodes = 1;
693 		return;
694 	}
695 
696 	/*
697 	 * Read boot property with CPU to APIC ID mapping table/array and fill
698 	 * in CPU to node ID mapping table with APIC ID for each CPU
699 	 */
700 	lgrp_plat_apic_ncpus =
701 	    lgrp_plat_process_cpu_apicids(lgrp_plat_cpu_node);
702 
703 	/*
704 	 * Determine which CPUs and memory are local to each other and number
705 	 * of NUMA nodes by reading ACPI System Resource Affinity Table (SRAT)
706 	 */
707 	if (lgrp_plat_apic_ncpus > 0) {
708 		int	retval;
709 
710 		retval = lgrp_plat_process_srat(srat_ptr,
711 		    lgrp_plat_node_domain, lgrp_plat_cpu_node,
712 		    lgrp_plat_apic_ncpus, lgrp_plat_node_memory);
713 		if (retval <= 0) {
714 			lgrp_plat_srat_error = retval;
715 			lgrp_plat_node_cnt = 1;
716 		} else {
717 			lgrp_plat_srat_error = 0;
718 			lgrp_plat_node_cnt = retval;
719 		}
720 	}
721 
722 	/*
723 	 * Try to use PCI config space registers on Opteron if there's an error
724 	 * processing CPU to APIC ID mapping or SRAT
725 	 */
726 	if ((lgrp_plat_apic_ncpus <= 0 || lgrp_plat_srat_error != 0) &&
727 	    is_opteron())
728 		opt_get_numa_config(&lgrp_plat_node_cnt, &lgrp_plat_mem_intrlv,
729 		    lgrp_plat_node_memory);
730 
731 	/*
732 	 * Don't bother to setup system for multiple lgroups and only use one
733 	 * memory node when memory is interleaved between any nodes or there is
734 	 * only one NUMA node
735 	 *
736 	 * NOTE: May need to change this for Dynamic Reconfiguration (DR)
737 	 *	 when and if it happens for x86/x64
738 	 */
739 	if (lgrp_plat_mem_intrlv || lgrp_plat_node_cnt == 1) {
740 		lgrp_plat_node_cnt = max_mem_nodes = 1;
741 		(void) lgrp_topo_ht_limit_set(1);
742 		return;
743 	}
744 
745 	/*
746 	 * Leaf lgroups on x86/x64 architectures contain one physical
747 	 * processor chip. Tune lgrp_expand_proc_thresh and
748 	 * lgrp_expand_proc_diff so that lgrp_choose() will spread
749 	 * things out aggressively.
750 	 */
751 	lgrp_expand_proc_thresh = LGRP_LOADAVG_THREAD_MAX / 2;
752 	lgrp_expand_proc_diff = 0;
753 
754 	/*
755 	 * There should be one memnode (physical page free list(s)) for
756 	 * each node
757 	 */
758 	max_mem_nodes = lgrp_plat_node_cnt;
759 
760 	/*
761 	 * Initialize min and max latency before reading SLIT or probing
762 	 */
763 	lgrp_plat_lat_stats.latency_min = -1;
764 	lgrp_plat_lat_stats.latency_max = 0;
765 
766 	/*
767 	 * Determine how far each NUMA node is from each other by
768 	 * reading ACPI System Locality Information Table (SLIT) if it
769 	 * exists
770 	 */
771 	lgrp_plat_slit_error = lgrp_plat_process_slit(slit_ptr,
772 	    lgrp_plat_node_cnt, lgrp_plat_node_memory,
773 	    &lgrp_plat_lat_stats);
774 	if (lgrp_plat_slit_error == 0)
775 		return;
776 
777 	/*
778 	 * Probe to determine latency between NUMA nodes when SLIT
779 	 * doesn't exist or make sense
780 	 */
781 	lgrp_plat_probe_flags |= LGRP_PLAT_PROBE_ENABLE;
782 
783 	/*
784 	 * Specify whether to probe using vendor ID register or page copy
785 	 * if hasn't been specified already or is overspecified
786 	 */
787 	probe_op = lgrp_plat_probe_flags &
788 	    (LGRP_PLAT_PROBE_PGCPY|LGRP_PLAT_PROBE_VENDOR);
789 
790 	if (probe_op == 0 ||
791 	    probe_op == (LGRP_PLAT_PROBE_PGCPY|LGRP_PLAT_PROBE_VENDOR)) {
792 		lgrp_plat_probe_flags &=
793 		    ~(LGRP_PLAT_PROBE_PGCPY|LGRP_PLAT_PROBE_VENDOR);
794 		if (is_opteron())
795 			lgrp_plat_probe_flags |=
796 			    LGRP_PLAT_PROBE_VENDOR;
797 		else
798 			lgrp_plat_probe_flags |= LGRP_PLAT_PROBE_PGCPY;
799 	}
800 
801 	/*
802 	 * Probing errors can mess up the lgroup topology and
803 	 * force us fall back to a 2 level lgroup topology.
804 	 * Here we bound how tall the lgroup topology can grow
805 	 * in hopes of avoiding any anamolies in probing from
806 	 * messing up the lgroup topology by limiting the
807 	 * accuracy of the latency topology.
808 	 *
809 	 * Assume that nodes will at least be configured in a
810 	 * ring, so limit height of lgroup topology to be less
811 	 * than number of nodes on a system with 4 or more
812 	 * nodes
813 	 */
814 	if (lgrp_plat_node_cnt >= 4 && lgrp_topo_ht_limit() ==
815 	    lgrp_topo_ht_limit_default())
816 		(void) lgrp_topo_ht_limit_set(lgrp_plat_node_cnt - 1);
817 #endif	/* __xpv */
818 }
819 
820 
821 /*
822  * Return latency between "from" and "to" lgroups
823  *
824  * This latency number can only be used for relative comparison
825  * between lgroups on the running system, cannot be used across platforms,
826  * and may not reflect the actual latency.  It is platform and implementation
827  * specific, so platform gets to decide its value.  It would be nice if the
828  * number was at least proportional to make comparisons more meaningful though.
829  */
830 /* ARGSUSED */
831 int
832 lgrp_plat_latency(lgrp_handle_t from, lgrp_handle_t to)
833 {
834 	lgrp_handle_t	src, dest;
835 	int		node;
836 
837 	if (max_mem_nodes == 1)
838 		return (0);
839 
840 	/*
841 	 * Return max latency for root lgroup
842 	 */
843 	if (from == LGRP_DEFAULT_HANDLE || to == LGRP_DEFAULT_HANDLE)
844 		return (lgrp_plat_lat_stats.latency_max);
845 
846 	src = from;
847 	dest = to;
848 
849 	/*
850 	 * Return 0 for nodes (lgroup platform handles) out of range
851 	 */
852 	if (src < 0 || src >= MAX_NODES || dest < 0 || dest >= MAX_NODES)
853 		return (0);
854 
855 	/*
856 	 * Probe from current CPU if its lgroup latencies haven't been set yet
857 	 * and we are trying to get latency from current CPU to some node
858 	 */
859 	node = lgrp_plat_cpu_to_node(CPU, lgrp_plat_cpu_node);
860 	ASSERT(node >= 0 && node < lgrp_plat_node_cnt);
861 	if (lgrp_plat_lat_stats.latencies[src][src] == 0 && node == src)
862 		lgrp_plat_probe();
863 
864 	return (lgrp_plat_lat_stats.latencies[src][dest]);
865 }
866 
867 
868 /*
869  * Platform-specific initialization
870  */
871 void
872 lgrp_plat_main_init(void)
873 {
874 	int	curnode;
875 	int	ht_limit;
876 	int	i;
877 
878 	/*
879 	 * Print a notice that MPO is disabled when memory is interleaved
880 	 * across nodes....Would do this when it is discovered, but can't
881 	 * because it happens way too early during boot....
882 	 */
883 	if (lgrp_plat_mem_intrlv)
884 		cmn_err(CE_NOTE,
885 		    "MPO disabled because memory is interleaved\n");
886 
887 	/*
888 	 * Don't bother to do any probing if it is disabled, there is only one
889 	 * node, or the height of the lgroup topology less than or equal to 2
890 	 */
891 	ht_limit = lgrp_topo_ht_limit();
892 	if (!(lgrp_plat_probe_flags & LGRP_PLAT_PROBE_ENABLE) ||
893 	    max_mem_nodes == 1 || ht_limit <= 2) {
894 		/*
895 		 * Setup lgroup latencies for 2 level lgroup topology
896 		 * (ie. local and remote only) if they haven't been set yet
897 		 */
898 		if (ht_limit == 2 && lgrp_plat_lat_stats.latency_min == -1 &&
899 		    lgrp_plat_lat_stats.latency_max == 0)
900 			lgrp_plat_2level_setup(lgrp_plat_node_memory,
901 			    &lgrp_plat_lat_stats);
902 		return;
903 	}
904 
905 	if (lgrp_plat_probe_flags & LGRP_PLAT_PROBE_VENDOR) {
906 		/*
907 		 * Should have been able to probe from CPU 0 when it was added
908 		 * to lgroup hierarchy, but may not have been able to then
909 		 * because it happens so early in boot that gethrtime() hasn't
910 		 * been initialized.  (:-(
911 		 */
912 		curnode = lgrp_plat_cpu_to_node(CPU, lgrp_plat_cpu_node);
913 		ASSERT(curnode >= 0 && curnode < lgrp_plat_node_cnt);
914 		if (lgrp_plat_lat_stats.latencies[curnode][curnode] == 0)
915 			lgrp_plat_probe();
916 
917 		return;
918 	}
919 
920 	/*
921 	 * When probing memory, use one page for every sample to determine
922 	 * lgroup topology and taking multiple samples
923 	 */
924 	if (lgrp_plat_probe_mem_config.probe_memsize == 0)
925 		lgrp_plat_probe_mem_config.probe_memsize = PAGESIZE *
926 		    lgrp_plat_probe_nsamples;
927 
928 	/*
929 	 * Map memory in each node needed for probing to determine latency
930 	 * topology
931 	 */
932 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
933 		int	mnode;
934 
935 		/*
936 		 * Skip this node and leave its probe page NULL
937 		 * if it doesn't have any memory
938 		 */
939 		mnode = plat_lgrphand_to_mem_node((lgrp_handle_t)i);
940 		if (!mem_node_config[mnode].exists) {
941 			lgrp_plat_probe_mem_config.probe_va[i] = NULL;
942 			continue;
943 		}
944 
945 		/*
946 		 * Allocate one kernel virtual page
947 		 */
948 		lgrp_plat_probe_mem_config.probe_va[i] = vmem_alloc(heap_arena,
949 		    lgrp_plat_probe_mem_config.probe_memsize, VM_NOSLEEP);
950 		if (lgrp_plat_probe_mem_config.probe_va[i] == NULL) {
951 			cmn_err(CE_WARN,
952 			    "lgrp_plat_main_init: couldn't allocate memory");
953 			return;
954 		}
955 
956 		/*
957 		 * Get PFN for first page in each node
958 		 */
959 		lgrp_plat_probe_mem_config.probe_pfn[i] =
960 		    mem_node_config[mnode].physbase;
961 
962 		/*
963 		 * Map virtual page to first page in node
964 		 */
965 		hat_devload(kas.a_hat, lgrp_plat_probe_mem_config.probe_va[i],
966 		    lgrp_plat_probe_mem_config.probe_memsize,
967 		    lgrp_plat_probe_mem_config.probe_pfn[i],
968 		    PROT_READ | PROT_WRITE | HAT_PLAT_NOCACHE,
969 		    HAT_LOAD_NOCONSIST);
970 	}
971 
972 	/*
973 	 * Probe from current CPU
974 	 */
975 	lgrp_plat_probe();
976 }
977 
978 
979 /*
980  * Return the maximum number of lgrps supported by the platform.
981  * Before lgrp topology is known it returns an estimate based on the number of
982  * nodes. Once topology is known it returns the actual maximim number of lgrps
983  * created. Since x86/x64 doesn't support Dynamic Reconfiguration (DR) and
984  * dynamic addition of new nodes, this number may not grow during system
985  * lifetime (yet).
986  */
987 int
988 lgrp_plat_max_lgrps(void)
989 {
990 	return (lgrp_topo_initialized ?
991 	    lgrp_alloc_max + 1 :
992 	    lgrp_plat_node_cnt * (lgrp_plat_node_cnt - 1) + 1);
993 }
994 
995 
996 /*
997  * Return the number of free pages in an lgroup.
998  *
999  * For query of LGRP_MEM_SIZE_FREE, return the number of base pagesize
1000  * pages on freelists.  For query of LGRP_MEM_SIZE_AVAIL, return the
1001  * number of allocatable base pagesize pages corresponding to the
1002  * lgroup (e.g. do not include page_t's, BOP_ALLOC()'ed memory, ..)
1003  * For query of LGRP_MEM_SIZE_INSTALL, return the amount of physical
1004  * memory installed, regardless of whether or not it's usable.
1005  */
1006 pgcnt_t
1007 lgrp_plat_mem_size(lgrp_handle_t plathand, lgrp_mem_query_t query)
1008 {
1009 	int	mnode;
1010 	pgcnt_t npgs = (pgcnt_t)0;
1011 	extern struct memlist *phys_avail;
1012 	extern struct memlist *phys_install;
1013 
1014 
1015 	if (plathand == LGRP_DEFAULT_HANDLE)
1016 		return (lgrp_plat_mem_size_default(plathand, query));
1017 
1018 	if (plathand != LGRP_NULL_HANDLE) {
1019 		mnode = plat_lgrphand_to_mem_node(plathand);
1020 		if (mnode >= 0 && mem_node_config[mnode].exists) {
1021 			switch (query) {
1022 			case LGRP_MEM_SIZE_FREE:
1023 				npgs = MNODE_PGCNT(mnode);
1024 				break;
1025 			case LGRP_MEM_SIZE_AVAIL:
1026 				npgs = mem_node_memlist_pages(mnode,
1027 				    phys_avail);
1028 				break;
1029 			case LGRP_MEM_SIZE_INSTALL:
1030 				npgs = mem_node_memlist_pages(mnode,
1031 				    phys_install);
1032 				break;
1033 			default:
1034 				break;
1035 			}
1036 		}
1037 	}
1038 	return (npgs);
1039 }
1040 
1041 
1042 /*
1043  * Return the platform handle of the lgroup that contains the physical memory
1044  * corresponding to the given page frame number
1045  */
1046 /* ARGSUSED */
1047 lgrp_handle_t
1048 lgrp_plat_pfn_to_hand(pfn_t pfn)
1049 {
1050 	int	mnode;
1051 
1052 	if (max_mem_nodes == 1)
1053 		return (LGRP_DEFAULT_HANDLE);
1054 
1055 	if (pfn > physmax)
1056 		return (LGRP_NULL_HANDLE);
1057 
1058 	mnode = plat_pfn_to_mem_node(pfn);
1059 	if (mnode < 0)
1060 		return (LGRP_NULL_HANDLE);
1061 
1062 	return (MEM_NODE_2_LGRPHAND(mnode));
1063 }
1064 
1065 
1066 /*
1067  * Probe memory in each node from current CPU to determine latency topology
1068  *
1069  * The probing code will probe the vendor ID register on the Northbridge of
1070  * Opteron processors and probe memory for other processors by default.
1071  *
1072  * Since probing is inherently error prone, the code takes laps across all the
1073  * nodes probing from each node to each of the other nodes some number of
1074  * times.  Furthermore, each node is probed some number of times before moving
1075  * onto the next one during each lap.  The minimum latency gotten between nodes
1076  * is kept as the latency between the nodes.
1077  *
1078  * After all that,  the probe times are adjusted by normalizing values that are
1079  * close to each other and local latencies are made the same.  Lastly, the
1080  * latencies are verified to make sure that certain conditions are met (eg.
1081  * local < remote, latency(a, b) == latency(b, a), etc.).
1082  *
1083  * If any of the conditions aren't met, the code will export a NUMA
1084  * configuration with the local CPUs and memory given by the SRAT or PCI config
1085  * space registers and one remote memory latency since it can't tell exactly
1086  * how far each node is from each other.
1087  */
1088 void
1089 lgrp_plat_probe(void)
1090 {
1091 	int				from;
1092 	int				i;
1093 	lgrp_plat_latency_stats_t	*lat_stats;
1094 	hrtime_t			probe_time;
1095 	int				to;
1096 
1097 	if (!(lgrp_plat_probe_flags & LGRP_PLAT_PROBE_ENABLE) ||
1098 	    max_mem_nodes == 1 || lgrp_topo_ht_limit() <= 2)
1099 		return;
1100 
1101 	/*
1102 	 * Determine ID of node containing current CPU
1103 	 */
1104 	from = lgrp_plat_cpu_to_node(CPU, lgrp_plat_cpu_node);
1105 	ASSERT(from >= 0 && from < lgrp_plat_node_cnt);
1106 	if (srat_ptr && lgrp_plat_srat_enable && !lgrp_plat_srat_error)
1107 		ASSERT(lgrp_plat_node_domain[from].exists);
1108 
1109 	/*
1110 	 * Don't need to probe if got times already
1111 	 */
1112 	lat_stats = &lgrp_plat_lat_stats;
1113 	if (lat_stats->latencies[from][from] != 0)
1114 		return;
1115 
1116 	/*
1117 	 * Read vendor ID in Northbridge or read and write page(s)
1118 	 * in each node from current CPU and remember how long it takes,
1119 	 * so we can build latency topology of machine later.
1120 	 * This should approximate the memory latency between each node.
1121 	 */
1122 	for (i = 0; i < lgrp_plat_probe_nrounds; i++) {
1123 		for (to = 0; to < lgrp_plat_node_cnt; to++) {
1124 			/*
1125 			 * Get probe time and bail out if can't get it yet
1126 			 */
1127 			probe_time = lgrp_plat_probe_time(to,
1128 			    lgrp_plat_cpu_node, &lgrp_plat_probe_mem_config,
1129 			    &lgrp_plat_lat_stats, &lgrp_plat_probe_stats);
1130 			if (probe_time == 0)
1131 				return;
1132 
1133 			/*
1134 			 * Keep lowest probe time as latency between nodes
1135 			 */
1136 			if (lat_stats->latencies[from][to] == 0 ||
1137 			    probe_time < lat_stats->latencies[from][to])
1138 				lat_stats->latencies[from][to] = probe_time;
1139 
1140 			/*
1141 			 * Update overall minimum and maximum probe times
1142 			 * across all nodes
1143 			 */
1144 			if (probe_time < lat_stats->latency_min ||
1145 			    lat_stats->latency_min == -1)
1146 				lat_stats->latency_min = probe_time;
1147 			if (probe_time > lat_stats->latency_max)
1148 				lat_stats->latency_max = probe_time;
1149 		}
1150 	}
1151 
1152 	/*
1153 	 * - Fix up latencies such that local latencies are same,
1154 	 *   latency(i, j) == latency(j, i), etc. (if possible)
1155 	 *
1156 	 * - Verify that latencies look ok
1157 	 *
1158 	 * - Fallback to just optimizing for local and remote if
1159 	 *   latencies didn't look right
1160 	 */
1161 	lgrp_plat_latency_adjust(lgrp_plat_node_memory, &lgrp_plat_lat_stats,
1162 	    &lgrp_plat_probe_stats);
1163 	lgrp_plat_probe_stats.probe_error_code =
1164 	    lgrp_plat_latency_verify(lgrp_plat_node_memory,
1165 	    &lgrp_plat_lat_stats);
1166 	if (lgrp_plat_probe_stats.probe_error_code)
1167 		lgrp_plat_2level_setup(lgrp_plat_node_memory,
1168 		    &lgrp_plat_lat_stats);
1169 }
1170 
1171 
1172 /*
1173  * Return platform handle for root lgroup
1174  */
1175 lgrp_handle_t
1176 lgrp_plat_root_hand(void)
1177 {
1178 	return (LGRP_DEFAULT_HANDLE);
1179 }
1180 
1181 
1182 /*
1183  * INTERNAL ROUTINES
1184  */
1185 
1186 
1187 /*
1188  * Update CPU to node mapping for given CPU and proximity domain (and returns
1189  * negative numbers for errors and positive ones for success)
1190  */
1191 static int
1192 lgrp_plat_cpu_node_update(node_domain_map_t *node_domain, int node_cnt,
1193     cpu_node_map_t *cpu_node, int nentries, uint32_t apicid, uint32_t domain)
1194 {
1195 	uint_t	i;
1196 	int	node;
1197 
1198 	/*
1199 	 * Get node number for proximity domain
1200 	 */
1201 	node = lgrp_plat_domain_to_node(node_domain, node_cnt, domain);
1202 	if (node == -1) {
1203 		node = lgrp_plat_node_domain_update(node_domain, node_cnt,
1204 		    domain);
1205 		if (node == -1)
1206 			return (-1);
1207 	}
1208 
1209 	/*
1210 	 * Search for entry with given APIC ID and fill in its node and
1211 	 * proximity domain IDs (if they haven't been set already)
1212 	 */
1213 	for (i = 0; i < nentries; i++) {
1214 		/*
1215 		 * Skip nonexistent entries and ones without matching APIC ID
1216 		 */
1217 		if (!cpu_node[i].exists || cpu_node[i].apicid != apicid)
1218 			continue;
1219 
1220 		/*
1221 		 * Just return if entry completely and correctly filled in
1222 		 * already
1223 		 */
1224 		if (cpu_node[i].prox_domain == domain &&
1225 		    cpu_node[i].node == node)
1226 			return (1);
1227 
1228 		/*
1229 		 * Fill in node and proximity domain IDs
1230 		 */
1231 		cpu_node[i].prox_domain = domain;
1232 		cpu_node[i].node = node;
1233 
1234 		return (0);
1235 	}
1236 
1237 	/*
1238 	 * Return error when entry for APIC ID wasn't found in table
1239 	 */
1240 	return (-2);
1241 }
1242 
1243 
1244 /*
1245  * Get node ID for given CPU
1246  */
1247 static int
1248 lgrp_plat_cpu_to_node(cpu_t *cp, cpu_node_map_t *cpu_node)
1249 {
1250 	processorid_t	cpuid;
1251 
1252 	if (cp == NULL)
1253 		return (-1);
1254 
1255 	cpuid = cp->cpu_id;
1256 	if (cpuid < 0 || cpuid >= max_ncpus)
1257 		return (-1);
1258 
1259 	/*
1260 	 * SRAT doesn't exist, isn't enabled, or there was an error processing
1261 	 * it, so return chip ID for Opteron and -1 otherwise.
1262 	 */
1263 	if (srat_ptr == NULL || !lgrp_plat_srat_enable ||
1264 	    lgrp_plat_srat_error) {
1265 		if (is_opteron())
1266 			return (pg_plat_hw_instance_id(cp, PGHW_CHIP));
1267 		return (-1);
1268 	}
1269 
1270 	/*
1271 	 * Return -1 when CPU to node ID mapping entry doesn't exist for given
1272 	 * CPU
1273 	 */
1274 	if (!cpu_node[cpuid].exists)
1275 		return (-1);
1276 
1277 	return (cpu_node[cpuid].node);
1278 }
1279 
1280 
1281 /*
1282  * Return node number for given proximity domain/system locality
1283  */
1284 static int
1285 lgrp_plat_domain_to_node(node_domain_map_t *node_domain, int node_cnt,
1286     uint32_t domain)
1287 {
1288 	uint_t	node;
1289 	uint_t	start;
1290 
1291 	/*
1292 	 * Hash proximity domain ID into node to domain mapping table (array),
1293 	 * search for entry with matching proximity domain ID, and return index
1294 	 * of matching entry as node ID.
1295 	 */
1296 	node = start = NODE_DOMAIN_HASH(domain, node_cnt);
1297 	do {
1298 		if (node_domain[node].prox_domain == domain &&
1299 		    node_domain[node].exists)
1300 			return (node);
1301 		node = NODE_DOMAIN_HASH(node + 1, node_cnt);
1302 	} while (node != start);
1303 	return (-1);
1304 }
1305 
1306 
1307 /*
1308  * Latencies must be within 1/(2**LGRP_LAT_TOLERANCE_SHIFT) of each other to
1309  * be considered same
1310  */
1311 #define	LGRP_LAT_TOLERANCE_SHIFT	4
1312 
1313 int	lgrp_plat_probe_lt_shift = LGRP_LAT_TOLERANCE_SHIFT;
1314 
1315 
1316 /*
1317  * Adjust latencies between nodes to be symmetric, normalize latencies between
1318  * any nodes that are within some tolerance to be same, and make local
1319  * latencies be same
1320  */
1321 static void
1322 lgrp_plat_latency_adjust(node_phys_addr_map_t *node_memory,
1323     lgrp_plat_latency_stats_t *lat_stats, lgrp_plat_probe_stats_t *probe_stats)
1324 {
1325 	int				i;
1326 	int				j;
1327 	int				k;
1328 	int				l;
1329 	u_longlong_t			max;
1330 	u_longlong_t			min;
1331 	u_longlong_t			t;
1332 	u_longlong_t			t1;
1333 	u_longlong_t			t2;
1334 	const lgrp_config_flag_t	cflag = LGRP_CONFIG_LAT_CHANGE_ALL;
1335 	int				lat_corrected[MAX_NODES][MAX_NODES];
1336 
1337 	/*
1338 	 * Nothing to do when this is an UMA machine or don't have args needed
1339 	 */
1340 	if (max_mem_nodes == 1)
1341 		return;
1342 
1343 	ASSERT(node_memory != NULL && lat_stats != NULL &&
1344 	    probe_stats != NULL);
1345 
1346 	/*
1347 	 * Make sure that latencies are symmetric between any two nodes
1348 	 * (ie. latency(node0, node1) == latency(node1, node0))
1349 	 */
1350 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
1351 		if (!node_memory[i].exists)
1352 			continue;
1353 
1354 		for (j = 0; j < lgrp_plat_node_cnt; j++) {
1355 			if (!node_memory[j].exists)
1356 				continue;
1357 
1358 			t1 = lat_stats->latencies[i][j];
1359 			t2 = lat_stats->latencies[j][i];
1360 
1361 			if (t1 == 0 || t2 == 0 || t1 == t2)
1362 				continue;
1363 
1364 			/*
1365 			 * Latencies should be same
1366 			 * - Use minimum of two latencies which should be same
1367 			 * - Track suspect probe times not within tolerance of
1368 			 *   min value
1369 			 * - Remember how much values are corrected by
1370 			 */
1371 			if (t1 > t2) {
1372 				t = t2;
1373 				probe_stats->probe_errors[i][j] += t1 - t2;
1374 				if (t1 - t2 > t2 >> lgrp_plat_probe_lt_shift) {
1375 					probe_stats->probe_suspect[i][j]++;
1376 					probe_stats->probe_suspect[j][i]++;
1377 				}
1378 			} else if (t2 > t1) {
1379 				t = t1;
1380 				probe_stats->probe_errors[j][i] += t2 - t1;
1381 				if (t2 - t1 > t1 >> lgrp_plat_probe_lt_shift) {
1382 					probe_stats->probe_suspect[i][j]++;
1383 					probe_stats->probe_suspect[j][i]++;
1384 				}
1385 			}
1386 
1387 			lat_stats->latencies[i][j] =
1388 			    lat_stats->latencies[j][i] = t;
1389 			lgrp_config(cflag, t1, t);
1390 			lgrp_config(cflag, t2, t);
1391 		}
1392 	}
1393 
1394 	/*
1395 	 * Keep track of which latencies get corrected
1396 	 */
1397 	for (i = 0; i < MAX_NODES; i++)
1398 		for (j = 0; j < MAX_NODES; j++)
1399 			lat_corrected[i][j] = 0;
1400 
1401 	/*
1402 	 * For every two nodes, see whether there is another pair of nodes which
1403 	 * are about the same distance apart and make the latencies be the same
1404 	 * if they are close enough together
1405 	 */
1406 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
1407 		if (!node_memory[i].exists)
1408 			continue;
1409 		for (j = 0; j < lgrp_plat_node_cnt; j++) {
1410 			if (!node_memory[j].exists)
1411 				continue;
1412 			/*
1413 			 * Pick one pair of nodes (i, j)
1414 			 * and get latency between them
1415 			 */
1416 			t1 = lat_stats->latencies[i][j];
1417 
1418 			/*
1419 			 * Skip this pair of nodes if there isn't a latency
1420 			 * for it yet
1421 			 */
1422 			if (t1 == 0)
1423 				continue;
1424 
1425 			for (k = 0; k < lgrp_plat_node_cnt; k++) {
1426 				if (!node_memory[k].exists)
1427 					continue;
1428 				for (l = 0; l < lgrp_plat_node_cnt; l++) {
1429 					if (!node_memory[l].exists)
1430 						continue;
1431 					/*
1432 					 * Pick another pair of nodes (k, l)
1433 					 * not same as (i, j) and get latency
1434 					 * between them
1435 					 */
1436 					if (k == i && l == j)
1437 						continue;
1438 
1439 					t2 = lat_stats->latencies[k][l];
1440 
1441 					/*
1442 					 * Skip this pair of nodes if there
1443 					 * isn't a latency for it yet
1444 					 */
1445 
1446 					if (t2 == 0)
1447 						continue;
1448 
1449 					/*
1450 					 * Skip nodes (k, l) if they already
1451 					 * have same latency as (i, j) or
1452 					 * their latency isn't close enough to
1453 					 * be considered/made the same
1454 					 */
1455 					if (t1 == t2 || (t1 > t2 && t1 - t2 >
1456 					    t1 >> lgrp_plat_probe_lt_shift) ||
1457 					    (t2 > t1 && t2 - t1 >
1458 					    t2 >> lgrp_plat_probe_lt_shift))
1459 						continue;
1460 
1461 					/*
1462 					 * Make latency(i, j) same as
1463 					 * latency(k, l), try to use latency
1464 					 * that has been adjusted already to get
1465 					 * more consistency (if possible), and
1466 					 * remember which latencies were
1467 					 * adjusted for next time
1468 					 */
1469 					if (lat_corrected[i][j]) {
1470 						t = t1;
1471 						lgrp_config(cflag, t2, t);
1472 						t2 = t;
1473 					} else if (lat_corrected[k][l]) {
1474 						t = t2;
1475 						lgrp_config(cflag, t1, t);
1476 						t1 = t;
1477 					} else {
1478 						if (t1 > t2)
1479 							t = t2;
1480 						else
1481 							t = t1;
1482 						lgrp_config(cflag, t1, t);
1483 						lgrp_config(cflag, t2, t);
1484 						t1 = t2 = t;
1485 					}
1486 
1487 					lat_stats->latencies[i][j] =
1488 					    lat_stats->latencies[k][l] = t;
1489 
1490 					lat_corrected[i][j] =
1491 					    lat_corrected[k][l] = 1;
1492 				}
1493 			}
1494 		}
1495 	}
1496 
1497 	/*
1498 	 * Local latencies should be same
1499 	 * - Find min and max local latencies
1500 	 * - Make all local latencies be minimum
1501 	 */
1502 	min = -1;
1503 	max = 0;
1504 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
1505 		if (!node_memory[i].exists)
1506 			continue;
1507 		t = lat_stats->latencies[i][i];
1508 		if (t == 0)
1509 			continue;
1510 		if (min == -1 || t < min)
1511 			min = t;
1512 		if (t > max)
1513 			max = t;
1514 	}
1515 	if (min != max) {
1516 		for (i = 0; i < lgrp_plat_node_cnt; i++) {
1517 			int	local;
1518 
1519 			if (!node_memory[i].exists)
1520 				continue;
1521 
1522 			local = lat_stats->latencies[i][i];
1523 			if (local == 0)
1524 				continue;
1525 
1526 			/*
1527 			 * Track suspect probe times that aren't within
1528 			 * tolerance of minimum local latency and how much
1529 			 * probe times are corrected by
1530 			 */
1531 			if (local - min > min >> lgrp_plat_probe_lt_shift)
1532 				probe_stats->probe_suspect[i][i]++;
1533 
1534 			probe_stats->probe_errors[i][i] += local - min;
1535 
1536 			/*
1537 			 * Make local latencies be minimum
1538 			 */
1539 			lgrp_config(LGRP_CONFIG_LAT_CHANGE, i, min);
1540 			lat_stats->latencies[i][i] = min;
1541 		}
1542 	}
1543 
1544 	/*
1545 	 * Determine max probe time again since just adjusted latencies
1546 	 */
1547 	lat_stats->latency_max = 0;
1548 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
1549 		if (!node_memory[i].exists)
1550 			continue;
1551 		for (j = 0; j < lgrp_plat_node_cnt; j++) {
1552 			if (!node_memory[j].exists)
1553 				continue;
1554 			t = lat_stats->latencies[i][j];
1555 			if (t > lat_stats->latency_max)
1556 				lat_stats->latency_max = t;
1557 		}
1558 	}
1559 }
1560 
1561 
1562 /*
1563  * Verify following about latencies between nodes:
1564  *
1565  * - Latencies should be symmetric (ie. latency(a, b) == latency(b, a))
1566  * - Local latencies same
1567  * - Local < remote
1568  * - Number of latencies seen is reasonable
1569  * - Number of occurrences of a given latency should be more than 1
1570  *
1571  * Returns:
1572  *	0	Success
1573  *	-1	Not symmetric
1574  *	-2	Local latencies not same
1575  *	-3	Local >= remote
1576  */
1577 static int
1578 lgrp_plat_latency_verify(node_phys_addr_map_t *node_memory,
1579     lgrp_plat_latency_stats_t *lat_stats)
1580 {
1581 	int				i;
1582 	int				j;
1583 	u_longlong_t			t1;
1584 	u_longlong_t			t2;
1585 
1586 	ASSERT(node_memory != NULL && lat_stats != NULL);
1587 
1588 	/*
1589 	 * Nothing to do when this is an UMA machine, lgroup topology is
1590 	 * limited to 2 levels, or there aren't any probe times yet
1591 	 */
1592 	if (max_mem_nodes == 1 || lgrp_topo_levels < 2 ||
1593 	    lat_stats->latencies[0][0] == 0)
1594 		return (0);
1595 
1596 	/*
1597 	 * Make sure that latencies are symmetric between any two nodes
1598 	 * (ie. latency(node0, node1) == latency(node1, node0))
1599 	 */
1600 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
1601 		if (!node_memory[i].exists)
1602 			continue;
1603 		for (j = 0; j < lgrp_plat_node_cnt; j++) {
1604 			if (!node_memory[j].exists)
1605 				continue;
1606 			t1 = lat_stats->latencies[i][j];
1607 			t2 = lat_stats->latencies[j][i];
1608 
1609 			if (t1 == 0 || t2 == 0 || t1 == t2)
1610 				continue;
1611 
1612 			return (-1);
1613 		}
1614 	}
1615 
1616 	/*
1617 	 * Local latencies should be same
1618 	 */
1619 	t1 = lat_stats->latencies[0][0];
1620 	for (i = 1; i < lgrp_plat_node_cnt; i++) {
1621 		if (!node_memory[i].exists)
1622 			continue;
1623 
1624 		t2 = lat_stats->latencies[i][i];
1625 		if (t2 == 0)
1626 			continue;
1627 
1628 		if (t1 == 0) {
1629 			t1 = t2;
1630 			continue;
1631 		}
1632 
1633 		if (t1 != t2)
1634 			return (-2);
1635 	}
1636 
1637 	/*
1638 	 * Local latencies should be less than remote
1639 	 */
1640 	if (t1) {
1641 		for (i = 0; i < lgrp_plat_node_cnt; i++) {
1642 			if (!node_memory[i].exists)
1643 				continue;
1644 			for (j = 0; j < lgrp_plat_node_cnt; j++) {
1645 				if (!node_memory[j].exists)
1646 					continue;
1647 				t2 = lat_stats->latencies[i][j];
1648 				if (i == j || t2 == 0)
1649 					continue;
1650 
1651 				if (t1 >= t2)
1652 					return (-3);
1653 			}
1654 		}
1655 	}
1656 
1657 	return (0);
1658 }
1659 
1660 
1661 /*
1662  * Return the number of free, allocatable, or installed
1663  * pages in an lgroup
1664  * This is a copy of the MAX_MEM_NODES == 1 version of the routine
1665  * used when MPO is disabled (i.e. single lgroup) or this is the root lgroup
1666  */
1667 /* ARGSUSED */
1668 static pgcnt_t
1669 lgrp_plat_mem_size_default(lgrp_handle_t lgrphand, lgrp_mem_query_t query)
1670 {
1671 	struct memlist *mlist;
1672 	pgcnt_t npgs = 0;
1673 	extern struct memlist *phys_avail;
1674 	extern struct memlist *phys_install;
1675 
1676 	switch (query) {
1677 	case LGRP_MEM_SIZE_FREE:
1678 		return ((pgcnt_t)freemem);
1679 	case LGRP_MEM_SIZE_AVAIL:
1680 		memlist_read_lock();
1681 		for (mlist = phys_avail; mlist; mlist = mlist->next)
1682 			npgs += btop(mlist->size);
1683 		memlist_read_unlock();
1684 		return (npgs);
1685 	case LGRP_MEM_SIZE_INSTALL:
1686 		memlist_read_lock();
1687 		for (mlist = phys_install; mlist; mlist = mlist->next)
1688 			npgs += btop(mlist->size);
1689 		memlist_read_unlock();
1690 		return (npgs);
1691 	default:
1692 		return ((pgcnt_t)0);
1693 	}
1694 }
1695 
1696 
1697 /*
1698  * Update node to proximity domain mappings for given domain and return node ID
1699  */
1700 static int
1701 lgrp_plat_node_domain_update(node_domain_map_t *node_domain, int node_cnt,
1702     uint32_t domain)
1703 {
1704 	uint_t	node;
1705 	uint_t	start;
1706 
1707 	/*
1708 	 * Hash proximity domain ID into node to domain mapping table (array)
1709 	 * and add entry for it into first non-existent or matching entry found
1710 	 */
1711 	node = start = NODE_DOMAIN_HASH(domain, node_cnt);
1712 	do {
1713 		/*
1714 		 * Entry doesn't exist yet, so create one for this proximity
1715 		 * domain and return node ID which is index into mapping table.
1716 		 */
1717 		if (!node_domain[node].exists) {
1718 			node_domain[node].exists = 1;
1719 			node_domain[node].prox_domain = domain;
1720 			return (node);
1721 		}
1722 
1723 		/*
1724 		 * Entry exists for this proximity domain already, so just
1725 		 * return node ID (index into table).
1726 		 */
1727 		if (node_domain[node].prox_domain == domain)
1728 			return (node);
1729 		node = NODE_DOMAIN_HASH(node + 1, node_cnt);
1730 	} while (node != start);
1731 
1732 	/*
1733 	 * Ran out of supported number of entries which shouldn't happen....
1734 	 */
1735 	ASSERT(node != start);
1736 	return (-1);
1737 }
1738 
1739 
1740 /*
1741  * Update node memory information for given proximity domain with specified
1742  * starting and ending physical address range (and return positive numbers for
1743  * success and negative ones for errors)
1744  */
1745 static int
1746 lgrp_plat_node_memory_update(node_domain_map_t *node_domain, int node_cnt,
1747     node_phys_addr_map_t *node_memory, uint64_t start, uint64_t end,
1748     uint32_t domain)
1749 {
1750 	int	node;
1751 
1752 	/*
1753 	 * Get node number for proximity domain
1754 	 */
1755 	node = lgrp_plat_domain_to_node(node_domain, node_cnt, domain);
1756 	if (node == -1) {
1757 		node = lgrp_plat_node_domain_update(node_domain, node_cnt,
1758 		    domain);
1759 		if (node == -1)
1760 			return (-1);
1761 	}
1762 
1763 	/*
1764 	 * Create entry in table for node if it doesn't exist
1765 	 */
1766 	if (!node_memory[node].exists) {
1767 		node_memory[node].exists = 1;
1768 		node_memory[node].start = btop(start);
1769 		node_memory[node].end = btop(end);
1770 		node_memory[node].prox_domain = domain;
1771 		return (0);
1772 	}
1773 
1774 	/*
1775 	 * Entry already exists for this proximity domain
1776 	 *
1777 	 * There may be more than one SRAT memory entry for a domain, so we may
1778 	 * need to update existing start or end address for the node.
1779 	 */
1780 	if (node_memory[node].prox_domain == domain) {
1781 		if (btop(start) < node_memory[node].start)
1782 			node_memory[node].start = btop(start);
1783 		if (btop(end) > node_memory[node].end)
1784 			node_memory[node].end = btop(end);
1785 		return (1);
1786 	}
1787 	return (-2);
1788 }
1789 
1790 
1791 /*
1792  * Return time needed to probe from current CPU to memory in given node
1793  */
1794 static hrtime_t
1795 lgrp_plat_probe_time(int to, cpu_node_map_t *cpu_node,
1796     lgrp_plat_probe_mem_config_t *probe_mem_config,
1797     lgrp_plat_latency_stats_t *lat_stats, lgrp_plat_probe_stats_t *probe_stats)
1798 {
1799 	caddr_t			buf;
1800 	hrtime_t		elapsed;
1801 	hrtime_t		end;
1802 	int			from;
1803 	int			i;
1804 	int			ipl;
1805 	hrtime_t		max;
1806 	hrtime_t		min;
1807 	hrtime_t		start;
1808 	extern int		use_sse_pagecopy;
1809 
1810 	/*
1811 	 * Determine ID of node containing current CPU
1812 	 */
1813 	from = lgrp_plat_cpu_to_node(CPU, cpu_node);
1814 	ASSERT(from >= 0 && from < lgrp_plat_node_cnt);
1815 
1816 	/*
1817 	 * Do common work for probing main memory
1818 	 */
1819 	if (lgrp_plat_probe_flags & LGRP_PLAT_PROBE_PGCPY) {
1820 		/*
1821 		 * Skip probing any nodes without memory and
1822 		 * set probe time to 0
1823 		 */
1824 		if (probe_mem_config->probe_va[to] == NULL) {
1825 			lat_stats->latencies[from][to] = 0;
1826 			return (0);
1827 		}
1828 
1829 		/*
1830 		 * Invalidate caches once instead of once every sample
1831 		 * which should cut cost of probing by a lot
1832 		 */
1833 		probe_stats->flush_cost = gethrtime();
1834 		invalidate_cache();
1835 		probe_stats->flush_cost = gethrtime() -
1836 		    probe_stats->flush_cost;
1837 		probe_stats->probe_cost_total += probe_stats->flush_cost;
1838 	}
1839 
1840 	/*
1841 	 * Probe from current CPU to given memory using specified operation
1842 	 * and take specified number of samples
1843 	 */
1844 	max = 0;
1845 	min = -1;
1846 	for (i = 0; i < lgrp_plat_probe_nsamples; i++) {
1847 		probe_stats->probe_cost = gethrtime();
1848 
1849 		/*
1850 		 * Can't measure probe time if gethrtime() isn't working yet
1851 		 */
1852 		if (probe_stats->probe_cost == 0 && gethrtime() == 0)
1853 			return (0);
1854 
1855 		if (lgrp_plat_probe_flags & LGRP_PLAT_PROBE_VENDOR) {
1856 			/*
1857 			 * Measure how long it takes to read vendor ID from
1858 			 * Northbridge
1859 			 */
1860 			elapsed = opt_probe_vendor(to, lgrp_plat_probe_nreads);
1861 		} else {
1862 			/*
1863 			 * Measure how long it takes to copy page
1864 			 * on top of itself
1865 			 */
1866 			buf = probe_mem_config->probe_va[to] + (i * PAGESIZE);
1867 
1868 			kpreempt_disable();
1869 			ipl = splhigh();
1870 			start = gethrtime();
1871 			if (use_sse_pagecopy)
1872 				hwblkpagecopy(buf, buf);
1873 			else
1874 				bcopy(buf, buf, PAGESIZE);
1875 			end = gethrtime();
1876 			elapsed = end - start;
1877 			splx(ipl);
1878 			kpreempt_enable();
1879 		}
1880 
1881 		probe_stats->probe_cost = gethrtime() -
1882 		    probe_stats->probe_cost;
1883 		probe_stats->probe_cost_total += probe_stats->probe_cost;
1884 
1885 		if (min == -1 || elapsed < min)
1886 			min = elapsed;
1887 		if (elapsed > max)
1888 			max = elapsed;
1889 	}
1890 
1891 	/*
1892 	 * Update minimum and maximum probe times between
1893 	 * these two nodes
1894 	 */
1895 	if (min < probe_stats->probe_min[from][to] ||
1896 	    probe_stats->probe_min[from][to] == 0)
1897 		probe_stats->probe_min[from][to] = min;
1898 
1899 	if (max > probe_stats->probe_max[from][to])
1900 		probe_stats->probe_max[from][to] = max;
1901 
1902 	return (min);
1903 }
1904 
1905 
1906 /*
1907  * Read boot property with CPU to APIC ID array, fill in CPU to node ID
1908  * mapping table with APIC ID for each CPU, and return number of CPU APIC IDs.
1909  *
1910  * NOTE: This code assumes that CPU IDs are assigned in order that they appear
1911  *       in in cpu_apicid_array boot property which is based on and follows
1912  *	 same ordering as processor list in ACPI MADT.  If the code in
1913  *	 usr/src/uts/i86pc/io/pcplusmp/apic.c that reads MADT and assigns
1914  *	 CPU IDs ever changes, then this code will need to change too....
1915  */
1916 static int
1917 lgrp_plat_process_cpu_apicids(cpu_node_map_t *cpu_node)
1918 {
1919 	int	boot_prop_len;
1920 	char	*boot_prop_name = BP_CPU_APICID_ARRAY;
1921 	uint8_t	cpu_apicid_array[UINT8_MAX + 1];
1922 	int	i;
1923 	int	n;
1924 
1925 	/*
1926 	 * Nothing to do when no array to fill in or not enough CPUs
1927 	 */
1928 	if (cpu_node == NULL)
1929 		return (-1);
1930 
1931 	/*
1932 	 * Check length of property value
1933 	 */
1934 	boot_prop_len = BOP_GETPROPLEN(bootops, boot_prop_name);
1935 	if (boot_prop_len <= 0 || boot_prop_len > sizeof (cpu_apicid_array))
1936 		return (-2);
1937 
1938 	/*
1939 	 * Calculate number of entries in array and return when there's just
1940 	 * one CPU since that's not very interesting for NUMA
1941 	 */
1942 	n = boot_prop_len / sizeof (uint8_t);
1943 	if (n == 1)
1944 		return (-3);
1945 
1946 	/*
1947 	 * Get CPU to APIC ID property value
1948 	 */
1949 	if (BOP_GETPROP(bootops, boot_prop_name, cpu_apicid_array) < 0)
1950 		return (-4);
1951 
1952 	/*
1953 	 * Fill in CPU to node ID mapping table with APIC ID for each CPU
1954 	 */
1955 	for (i = 0; i < n; i++) {
1956 		cpu_node[i].exists = 1;
1957 		cpu_node[i].apicid = cpu_apicid_array[i];
1958 	}
1959 
1960 	/*
1961 	 * Return number of CPUs based on number of APIC IDs
1962 	 */
1963 	return (n);
1964 }
1965 
1966 
1967 /*
1968  * Read ACPI System Locality Information Table (SLIT) to determine how far each
1969  * NUMA node is from each other
1970  */
1971 static int
1972 lgrp_plat_process_slit(struct slit *tp, uint_t node_cnt,
1973     node_phys_addr_map_t *node_memory, lgrp_plat_latency_stats_t *lat_stats)
1974 {
1975 	int		i;
1976 	int		j;
1977 	int		localities;
1978 	hrtime_t	max;
1979 	hrtime_t	min;
1980 	int		retval;
1981 	uint8_t		*slit_entries;
1982 
1983 	if (tp == NULL || !lgrp_plat_slit_enable)
1984 		return (1);
1985 
1986 	if (lat_stats == NULL)
1987 		return (2);
1988 
1989 	localities = tp->number;
1990 	if (localities != node_cnt)
1991 		return (3);
1992 
1993 	min = lat_stats->latency_min;
1994 	max = lat_stats->latency_max;
1995 
1996 	/*
1997 	 * Fill in latency matrix based on SLIT entries
1998 	 */
1999 	slit_entries = tp->entry;
2000 	for (i = 0; i < localities; i++) {
2001 		for (j = 0; j < localities; j++) {
2002 			uint8_t	latency;
2003 
2004 			latency = slit_entries[(i * localities) + j];
2005 			lat_stats->latencies[i][j] = latency;
2006 			if (latency < min || min == -1)
2007 				min = latency;
2008 			if (latency > max)
2009 				max = latency;
2010 		}
2011 	}
2012 
2013 	/*
2014 	 * Verify that latencies/distances given in SLIT look reasonable
2015 	 */
2016 	retval = lgrp_plat_latency_verify(node_memory, lat_stats);
2017 
2018 	if (retval) {
2019 		/*
2020 		 * Reinitialize (zero) latency table since SLIT doesn't look
2021 		 * right
2022 		 */
2023 		for (i = 0; i < localities; i++) {
2024 			for (j = 0; j < localities; j++)
2025 				lat_stats->latencies[i][j] = 0;
2026 		}
2027 	} else {
2028 		/*
2029 		 * Update min and max latencies seen since SLIT looks valid
2030 		 */
2031 		lat_stats->latency_min = min;
2032 		lat_stats->latency_max = max;
2033 	}
2034 
2035 	return (retval);
2036 }
2037 
2038 
2039 /*
2040  * Read ACPI System Resource Affinity Table (SRAT) to determine which CPUs
2041  * and memory are local to each other in the same NUMA node and return number
2042  * of nodes
2043  */
2044 static int
2045 lgrp_plat_process_srat(struct srat *tp, node_domain_map_t *node_domain,
2046     cpu_node_map_t *cpu_node, int cpu_count, node_phys_addr_map_t *node_memory)
2047 {
2048 	struct srat_item	*srat_end;
2049 	int			i;
2050 	struct srat_item	*item;
2051 	int			node_cnt;
2052 	int			proc_entry_count;
2053 
2054 	/*
2055 	 * Nothing to do when no SRAT or disabled
2056 	 */
2057 	if (tp == NULL || !lgrp_plat_srat_enable)
2058 		return (-1);
2059 
2060 	/*
2061 	 * Determine number of nodes by counting number of proximity domains in
2062 	 * SRAT and return if number of nodes is 1 or less since don't need to
2063 	 * read SRAT then
2064 	 */
2065 	node_cnt = lgrp_plat_srat_domains(tp);
2066 	if (node_cnt == 1)
2067 		return (1);
2068 	else if (node_cnt <= 0)
2069 		return (-2);
2070 
2071 	/*
2072 	 * Walk through SRAT, examining each CPU and memory entry to determine
2073 	 * which CPUs and memory belong to which node.
2074 	 */
2075 	item = tp->list;
2076 	srat_end = (struct srat_item *)(tp->hdr.len + (uintptr_t)tp);
2077 	proc_entry_count = 0;
2078 	while (item < srat_end) {
2079 		uint32_t	apic_id;
2080 		uint32_t	domain;
2081 		uint64_t	end;
2082 		uint64_t	length;
2083 		uint64_t	start;
2084 
2085 		switch (item->type) {
2086 		case SRAT_PROCESSOR:	/* CPU entry */
2087 			if (!(item->i.p.flags & SRAT_ENABLED) ||
2088 			    cpu_node == NULL)
2089 				break;
2090 
2091 			/*
2092 			 * Calculate domain (node) ID and fill in APIC ID to
2093 			 * domain/node mapping table
2094 			 */
2095 			domain = item->i.p.domain1;
2096 			for (i = 0; i < 3; i++) {
2097 				domain += item->i.p.domain2[i] <<
2098 				    ((i + 1) * 8);
2099 			}
2100 			apic_id = item->i.p.apic_id;
2101 
2102 			if (lgrp_plat_cpu_node_update(node_domain, node_cnt,
2103 			    cpu_node, cpu_count, apic_id, domain) < 0)
2104 				return (-3);
2105 
2106 			proc_entry_count++;
2107 			break;
2108 
2109 		case SRAT_MEMORY:	/* memory entry */
2110 			if (!(item->i.m.flags & SRAT_ENABLED) ||
2111 			    node_memory == NULL)
2112 				break;
2113 
2114 			/*
2115 			 * Get domain (node) ID and fill in domain/node
2116 			 * to memory mapping table
2117 			 */
2118 			domain = item->i.m.domain;
2119 			start = item->i.m.base_addr;
2120 			length = item->i.m.len;
2121 			end = start + length - 1;
2122 
2123 			if (lgrp_plat_node_memory_update(node_domain, node_cnt,
2124 			    node_memory, start, end, domain) < 0)
2125 				return (-4);
2126 			break;
2127 
2128 		default:
2129 			break;
2130 		}
2131 
2132 		item = (struct srat_item *)((uintptr_t)item + item->len);
2133 	}
2134 
2135 	/*
2136 	 * Should have seen at least as many SRAT processor entries as CPUs
2137 	 */
2138 	if (proc_entry_count < cpu_count)
2139 		return (-5);
2140 
2141 	return (node_cnt);
2142 }
2143 
2144 
2145 /*
2146  * Return number of proximity domains given in ACPI SRAT
2147  */
2148 static int
2149 lgrp_plat_srat_domains(struct srat *tp)
2150 {
2151 	int			domain_cnt;
2152 	struct srat_item	*end;
2153 	int			i;
2154 	struct srat_item	*item;
2155 	node_domain_map_t	node_domain[MAX_NODES];
2156 
2157 
2158 	if (tp == NULL || !lgrp_plat_srat_enable)
2159 		return (1);
2160 
2161 	/*
2162 	 * Walk through SRAT, examining each CPU and memory entry to determine
2163 	 * proximity domain ID for each.
2164 	 */
2165 	domain_cnt = 0;
2166 	item = tp->list;
2167 	end = (struct srat_item *)(tp->hdr.len + (uintptr_t)tp);
2168 	bzero(node_domain, MAX_NODES * sizeof (node_domain_map_t));
2169 	while (item < end) {
2170 		uint32_t	domain;
2171 		boolean_t	overflow;
2172 		uint_t		start;
2173 
2174 		switch (item->type) {
2175 		case SRAT_PROCESSOR:	/* CPU entry */
2176 			if (!(item->i.p.flags & SRAT_ENABLED))
2177 				break;
2178 			domain = item->i.p.domain1;
2179 			for (i = 0; i < 3; i++) {
2180 				domain += item->i.p.domain2[i] <<
2181 				    ((i + 1) * 8);
2182 			}
2183 			break;
2184 
2185 		case SRAT_MEMORY:	/* memory entry */
2186 			if (!(item->i.m.flags & SRAT_ENABLED))
2187 				break;
2188 			domain = item->i.m.domain;
2189 			break;
2190 
2191 		default:
2192 			break;
2193 		}
2194 
2195 		/*
2196 		 * Count and keep track of which proximity domain IDs seen
2197 		 */
2198 		start = i = domain % MAX_NODES;
2199 		overflow = B_TRUE;
2200 		do {
2201 			/*
2202 			 * Create entry for proximity domain and increment
2203 			 * count when no entry exists where proximity domain
2204 			 * hashed
2205 			 */
2206 			if (!node_domain[i].exists) {
2207 				node_domain[i].exists = 1;
2208 				node_domain[i].prox_domain = domain;
2209 				domain_cnt++;
2210 				overflow = B_FALSE;
2211 				break;
2212 			}
2213 
2214 			/*
2215 			 * Nothing to do when proximity domain seen already
2216 			 * and its entry exists
2217 			 */
2218 			if (node_domain[i].prox_domain == domain) {
2219 				overflow = B_FALSE;
2220 				break;
2221 			}
2222 
2223 			/*
2224 			 * Entry exists where proximity domain hashed, but for
2225 			 * different proximity domain so keep search for empty
2226 			 * slot to put it or matching entry whichever comes
2227 			 * first.
2228 			 */
2229 			i = (i + 1) % MAX_NODES;
2230 		} while (i != start);
2231 
2232 		/*
2233 		 * Didn't find empty or matching entry which means have more
2234 		 * proximity domains than supported nodes (:-(
2235 		 */
2236 		ASSERT(overflow != B_TRUE);
2237 		if (overflow == B_TRUE)
2238 			return (-1);
2239 
2240 		item = (struct srat_item *)((uintptr_t)item + item->len);
2241 	}
2242 	return (domain_cnt);
2243 }
2244 
2245 
2246 /*
2247  * Set lgroup latencies for 2 level lgroup topology
2248  */
2249 static void
2250 lgrp_plat_2level_setup(node_phys_addr_map_t *node_memory,
2251     lgrp_plat_latency_stats_t *lat_stats)
2252 {
2253 	int	i;
2254 
2255 	ASSERT(node_memory != NULL && lat_stats != NULL);
2256 
2257 	if (lgrp_plat_node_cnt >= 4)
2258 		cmn_err(CE_NOTE,
2259 		    "MPO only optimizing for local and remote\n");
2260 	for (i = 0; i < lgrp_plat_node_cnt; i++) {
2261 		int	j;
2262 
2263 		if (!node_memory[i].exists)
2264 			continue;
2265 		for (j = 0; j < lgrp_plat_node_cnt; j++) {
2266 			if (!node_memory[j].exists)
2267 				continue;
2268 			if (i == j)
2269 				lat_stats->latencies[i][j] = 2;
2270 			else
2271 				lat_stats->latencies[i][j] = 3;
2272 		}
2273 	}
2274 	lat_stats->latency_min = 2;
2275 	lat_stats->latency_max = 3;
2276 	lgrp_config(LGRP_CONFIG_FLATTEN, 2, 0);
2277 }
2278 
2279 
2280 /*
2281  * The following Opteron specific constants, macros, types, and routines define
2282  * PCI configuration space registers and how to read them to determine the NUMA
2283  * configuration of *supported* Opteron processors.  They provide the same
2284  * information that may be gotten from the ACPI System Resource Affinity Table
2285  * (SRAT) if it exists on the machine of interest.
2286  *
2287  * The AMD BIOS and Kernel Developer's Guide (BKDG) for the processor family
2288  * of interest describes all of these registers and their contents.  The main
2289  * registers used by this code to determine the NUMA configuration of the
2290  * machine are the node ID register for the number of NUMA nodes and the DRAM
2291  * address map registers for the physical address range of each node.
2292  *
2293  * NOTE: The format and how to determine the NUMA configuration using PCI
2294  *	 config space registers may change or may not be supported in future
2295  *	 Opteron processor families.
2296  */
2297 
2298 /*
2299  * How many bits to shift Opteron DRAM Address Map base and limit registers
2300  * to get actual value
2301  */
2302 #define	OPT_DRAMADDR_HI_LSHIFT_ADDR	40	/* shift left for address */
2303 #define	OPT_DRAMADDR_LO_LSHIFT_ADDR	8	/* shift left for address */
2304 
2305 #define	OPT_DRAMADDR_HI_MASK_ADDR	0x000000FF /* address bits 47-40 */
2306 #define	OPT_DRAMADDR_LO_MASK_ADDR	0xFFFF0000 /* address bits 39-24 */
2307 
2308 #define	OPT_DRAMADDR_LO_MASK_OFF	0xFFFFFF /* offset for address */
2309 
2310 /*
2311  * Macros to derive addresses from Opteron DRAM Address Map registers
2312  */
2313 #define	OPT_DRAMADDR_HI(reg) \
2314 	(((u_longlong_t)reg & OPT_DRAMADDR_HI_MASK_ADDR) << \
2315 	    OPT_DRAMADDR_HI_LSHIFT_ADDR)
2316 
2317 #define	OPT_DRAMADDR_LO(reg) \
2318 	(((u_longlong_t)reg & OPT_DRAMADDR_LO_MASK_ADDR) << \
2319 	    OPT_DRAMADDR_LO_LSHIFT_ADDR)
2320 
2321 #define	OPT_DRAMADDR(high, low) \
2322 	(OPT_DRAMADDR_HI(high) | OPT_DRAMADDR_LO(low))
2323 
2324 /*
2325  * Bit masks defining what's in Opteron DRAM Address Map base register
2326  */
2327 #define	OPT_DRAMBASE_LO_MASK_RE		0x1	/* read enable */
2328 #define	OPT_DRAMBASE_LO_MASK_WE		0x2	/* write enable */
2329 #define	OPT_DRAMBASE_LO_MASK_INTRLVEN	0x700	/* interleave */
2330 
2331 /*
2332  * Bit masks defining what's in Opteron DRAM Address Map limit register
2333  */
2334 #define	OPT_DRAMLIMIT_LO_MASK_DSTNODE	0x7		/* destination node */
2335 #define	OPT_DRAMLIMIT_LO_MASK_INTRLVSEL	0x700		/* interleave select */
2336 
2337 
2338 /*
2339  * Opteron Node ID register in PCI configuration space contains
2340  * number of nodes in system, etc. for Opteron K8.  The following
2341  * constants and macros define its contents, structure, and access.
2342  */
2343 
2344 /*
2345  * Bit masks defining what's in Opteron Node ID register
2346  */
2347 #define	OPT_NODE_MASK_ID	0x7	/* node ID */
2348 #define	OPT_NODE_MASK_CNT	0x70	/* node count */
2349 #define	OPT_NODE_MASK_IONODE	0x700	/* Hypertransport I/O hub node ID */
2350 #define	OPT_NODE_MASK_LCKNODE	0x7000	/* lock controller node ID */
2351 #define	OPT_NODE_MASK_CPUCNT	0xF0000	/* CPUs in system (0 means 1 CPU)  */
2352 
2353 /*
2354  * How many bits in Opteron Node ID register to shift right to get actual value
2355  */
2356 #define	OPT_NODE_RSHIFT_CNT	0x4	/* shift right for node count value */
2357 
2358 /*
2359  * Macros to get values from Opteron Node ID register
2360  */
2361 #define	OPT_NODE_CNT(reg) \
2362 	((reg & OPT_NODE_MASK_CNT) >> OPT_NODE_RSHIFT_CNT)
2363 
2364 /*
2365  * Macro to setup PCI Extended Configuration Space (ECS) address to give to
2366  * "in/out" instructions
2367  *
2368  * NOTE: Should only be used in lgrp_plat_init() before MMIO setup because any
2369  *	 other uses should just do MMIO to access PCI ECS.
2370  *	 Must enable special bit in Northbridge Configuration Register on
2371  *	 Greyhound for extended CF8 space access to be able to access PCI ECS
2372  *	 using "in/out" instructions and restore special bit after done
2373  *	 accessing PCI ECS.
2374  */
2375 #define	OPT_PCI_ECS_ADDR(bus, device, function, reg) \
2376 	(PCI_CONE | (((bus) & 0xff) << 16) | (((device & 0x1f)) << 11)  | \
2377 	    (((function) & 0x7) << 8) | ((reg) & 0xfc) | \
2378 	    ((((reg) >> 8) & 0xf) << 24))
2379 
2380 /*
2381  * PCI configuration space registers accessed by specifying
2382  * a bus, device, function, and offset.  The following constants
2383  * define the values needed to access Opteron K8 configuration
2384  * info to determine its node topology
2385  */
2386 
2387 #define	OPT_PCS_BUS_CONFIG	0	/* Hypertransport config space bus */
2388 
2389 /*
2390  * Opteron PCI configuration space register function values
2391  */
2392 #define	OPT_PCS_FUNC_HT		0	/* Hypertransport configuration */
2393 #define	OPT_PCS_FUNC_ADDRMAP	1	/* Address map configuration */
2394 #define	OPT_PCS_FUNC_DRAM	2	/* DRAM configuration */
2395 #define	OPT_PCS_FUNC_MISC	3	/* Miscellaneous configuration */
2396 
2397 /*
2398  * PCI Configuration Space register offsets
2399  */
2400 #define	OPT_PCS_OFF_VENDOR	0x0	/* device/vendor ID register */
2401 #define	OPT_PCS_OFF_DRAMBASE_HI	0x140	/* DRAM Base register (node 0) */
2402 #define	OPT_PCS_OFF_DRAMBASE_LO	0x40	/* DRAM Base register (node 0) */
2403 #define	OPT_PCS_OFF_NODEID	0x60	/* Node ID register */
2404 
2405 /*
2406  * Opteron PCI Configuration Space device IDs for nodes
2407  */
2408 #define	OPT_PCS_DEV_NODE0		24	/* device number for node 0 */
2409 
2410 
2411 /*
2412  * Opteron DRAM address map gives base and limit for physical memory in a node
2413  */
2414 typedef	struct opt_dram_addr_map {
2415 	uint32_t	base_hi;
2416 	uint32_t	base_lo;
2417 	uint32_t	limit_hi;
2418 	uint32_t	limit_lo;
2419 } opt_dram_addr_map_t;
2420 
2421 
2422 /*
2423  * Supported AMD processor families
2424  */
2425 #define	AMD_FAMILY_HAMMER	15
2426 #define	AMD_FAMILY_GREYHOUND	16
2427 
2428 /*
2429  * Whether to have is_opteron() return 1 even when processor isn't supported
2430  */
2431 uint_t	is_opteron_override = 0;
2432 
2433 /*
2434  * AMD processor family for current CPU
2435  */
2436 uint_t	opt_family = 0;
2437 
2438 
2439 /*
2440  * Determine whether we're running on a supported AMD Opteron since reading
2441  * node count and DRAM address map registers may have different format or
2442  * may not be supported across processor families
2443  */
2444 static int
2445 is_opteron(void)
2446 {
2447 
2448 	if (x86_vendor != X86_VENDOR_AMD)
2449 		return (0);
2450 
2451 	opt_family = cpuid_getfamily(CPU);
2452 	if (opt_family == AMD_FAMILY_HAMMER ||
2453 	    opt_family == AMD_FAMILY_GREYHOUND || is_opteron_override)
2454 		return (1);
2455 	else
2456 		return (0);
2457 }
2458 
2459 
2460 /*
2461  * Determine NUMA configuration for Opteron from registers that live in PCI
2462  * configuration space
2463  */
2464 static void
2465 opt_get_numa_config(uint_t *node_cnt, int *mem_intrlv,
2466     node_phys_addr_map_t *node_memory)
2467 {
2468 	uint_t				bus;
2469 	uint_t				dev;
2470 	struct opt_dram_addr_map	dram_map[MAX_NODES];
2471 	uint_t				node;
2472 	uint_t				node_info[MAX_NODES];
2473 	uint_t				off_hi;
2474 	uint_t				off_lo;
2475 	uint64_t			nb_cfg_reg;
2476 
2477 	/*
2478 	 * Read configuration registers from PCI configuration space to
2479 	 * determine node information, which memory is in each node, etc.
2480 	 *
2481 	 * Write to PCI configuration space address register to specify
2482 	 * which configuration register to read and read/write PCI
2483 	 * configuration space data register to get/set contents
2484 	 */
2485 	bus = OPT_PCS_BUS_CONFIG;
2486 	dev = OPT_PCS_DEV_NODE0;
2487 	off_hi = OPT_PCS_OFF_DRAMBASE_HI;
2488 	off_lo = OPT_PCS_OFF_DRAMBASE_LO;
2489 
2490 	/*
2491 	 * Read node ID register for node 0 to get node count
2492 	 */
2493 	node_info[0] = pci_getl_func(bus, dev, OPT_PCS_FUNC_HT,
2494 	    OPT_PCS_OFF_NODEID);
2495 	*node_cnt = OPT_NODE_CNT(node_info[0]) + 1;
2496 
2497 	/*
2498 	 * If number of nodes is more than maximum supported, then set node
2499 	 * count to 1 and treat system as UMA instead of NUMA.
2500 	 */
2501 	if (*node_cnt > MAX_NODES) {
2502 		*node_cnt = 1;
2503 		return;
2504 	}
2505 
2506 	/*
2507 	 * For Greyhound, PCI Extended Configuration Space must be enabled to
2508 	 * read high DRAM address map base and limit registers
2509 	 */
2510 	if (opt_family == AMD_FAMILY_GREYHOUND) {
2511 		nb_cfg_reg = rdmsr(MSR_AMD_NB_CFG);
2512 		if ((nb_cfg_reg & AMD_GH_NB_CFG_EN_ECS) == 0)
2513 			wrmsr(MSR_AMD_NB_CFG,
2514 			    nb_cfg_reg | AMD_GH_NB_CFG_EN_ECS);
2515 	}
2516 
2517 	for (node = 0; node < *node_cnt; node++) {
2518 		uint32_t	base_hi;
2519 		uint32_t	base_lo;
2520 		uint32_t	limit_hi;
2521 		uint32_t	limit_lo;
2522 
2523 		/*
2524 		 * Read node ID register (except for node 0 which we just read)
2525 		 */
2526 		if (node > 0) {
2527 			node_info[node] = pci_getl_func(bus, dev,
2528 			    OPT_PCS_FUNC_HT, OPT_PCS_OFF_NODEID);
2529 		}
2530 
2531 		/*
2532 		 * Read DRAM base and limit registers which specify
2533 		 * physical memory range of each node
2534 		 */
2535 		if (opt_family != AMD_FAMILY_GREYHOUND)
2536 			base_hi = 0;
2537 		else {
2538 			outl(PCI_CONFADD, OPT_PCI_ECS_ADDR(bus, dev,
2539 			    OPT_PCS_FUNC_ADDRMAP, off_hi));
2540 			base_hi = dram_map[node].base_hi =
2541 			    inl(PCI_CONFDATA);
2542 		}
2543 		base_lo = dram_map[node].base_lo = pci_getl_func(bus, dev,
2544 		    OPT_PCS_FUNC_ADDRMAP, off_lo);
2545 
2546 		if ((dram_map[node].base_lo & OPT_DRAMBASE_LO_MASK_INTRLVEN) &&
2547 		    mem_intrlv)
2548 			*mem_intrlv = *mem_intrlv + 1;
2549 
2550 		off_hi += 4;	/* high limit register offset */
2551 		if (opt_family != AMD_FAMILY_GREYHOUND)
2552 			limit_hi = 0;
2553 		else {
2554 			outl(PCI_CONFADD, OPT_PCI_ECS_ADDR(bus, dev,
2555 			    OPT_PCS_FUNC_ADDRMAP, off_hi));
2556 			limit_hi = dram_map[node].limit_hi =
2557 			    inl(PCI_CONFDATA);
2558 		}
2559 
2560 		off_lo += 4;	/* low limit register offset */
2561 		limit_lo = dram_map[node].limit_lo = pci_getl_func(bus,
2562 		    dev, OPT_PCS_FUNC_ADDRMAP, off_lo);
2563 
2564 		/*
2565 		 * Increment device number to next node and register offsets
2566 		 * for DRAM base register of next node
2567 		 */
2568 		off_hi += 4;
2569 		off_lo += 4;
2570 		dev++;
2571 
2572 		/*
2573 		 * Both read and write enable bits must be enabled in DRAM
2574 		 * address map base register for physical memory to exist in
2575 		 * node
2576 		 */
2577 		if ((base_lo & OPT_DRAMBASE_LO_MASK_RE) == 0 ||
2578 		    (base_lo & OPT_DRAMBASE_LO_MASK_WE) == 0) {
2579 			/*
2580 			 * Mark node memory as non-existent and set start and
2581 			 * end addresses to be same in node_memory[]
2582 			 */
2583 			node_memory[node].exists = 0;
2584 			node_memory[node].start = node_memory[node].end =
2585 			    (pfn_t)-1;
2586 			continue;
2587 		}
2588 
2589 		/*
2590 		 * Mark node memory as existing and remember physical address
2591 		 * range of each node for use later
2592 		 */
2593 		node_memory[node].exists = 1;
2594 
2595 		node_memory[node].start = btop(OPT_DRAMADDR(base_hi, base_lo));
2596 
2597 		node_memory[node].end = btop(OPT_DRAMADDR(limit_hi, limit_lo) |
2598 		    OPT_DRAMADDR_LO_MASK_OFF);
2599 	}
2600 
2601 	/*
2602 	 * Restore PCI Extended Configuration Space enable bit
2603 	 */
2604 	if (opt_family == AMD_FAMILY_GREYHOUND) {
2605 		if ((nb_cfg_reg & AMD_GH_NB_CFG_EN_ECS) == 0)
2606 			wrmsr(MSR_AMD_NB_CFG, nb_cfg_reg);
2607 	}
2608 }
2609 
2610 
2611 /*
2612  * Return average amount of time to read vendor ID register on Northbridge
2613  * N times on specified destination node from current CPU
2614  */
2615 static hrtime_t
2616 opt_probe_vendor(int dest_node, int nreads)
2617 {
2618 	int		cnt;
2619 	uint_t		dev;
2620 	/* LINTED: set but not used in function */
2621 	volatile uint_t	dev_vendor;
2622 	hrtime_t	elapsed;
2623 	hrtime_t	end;
2624 	int		ipl;
2625 	hrtime_t	start;
2626 
2627 	dev = OPT_PCS_DEV_NODE0 + dest_node;
2628 	kpreempt_disable();
2629 	ipl = spl8();
2630 	outl(PCI_CONFADD, PCI_CADDR1(0, dev, OPT_PCS_FUNC_DRAM,
2631 	    OPT_PCS_OFF_VENDOR));
2632 	start = gethrtime();
2633 	for (cnt = 0; cnt < nreads; cnt++)
2634 		dev_vendor = inl(PCI_CONFDATA);
2635 	end = gethrtime();
2636 	elapsed = (end - start) / nreads;
2637 	splx(ipl);
2638 	kpreempt_enable();
2639 	return (elapsed);
2640 }
2641