xref: /openbmc/linux/arch/parisc/kernel/inventory.c (revision 423997ff)
1 /*
2  * inventory.c
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  *
9  * Copyright (c) 1999 The Puffin Group (David Kennedy and Alex deVries)
10  * Copyright (c) 2001 Matthew Wilcox for Hewlett-Packard
11  *
12  * These are the routines to discover what hardware exists in this box.
13  * This task is complicated by there being 3 different ways of
14  * performing an inventory, depending largely on the age of the box.
15  * The recommended way to do this is to check to see whether the machine
16  * is a `Snake' first, then try System Map, then try PAT.  We try System
17  * Map before checking for a Snake -- this probably doesn't cause any
18  * problems, but...
19  */
20 
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/mm.h>
26 #include <asm/hardware.h>
27 #include <asm/io.h>
28 #include <asm/mmzone.h>
29 #include <asm/pdc.h>
30 #include <asm/pdcpat.h>
31 #include <asm/processor.h>
32 #include <asm/page.h>
33 #include <asm/parisc-device.h>
34 #include <asm/tlbflush.h>
35 
36 /*
37 ** Debug options
38 ** DEBUG_PAT Dump details which PDC PAT provides about ranges/devices.
39 */
40 #undef DEBUG_PAT
41 
42 int pdc_type __ro_after_init = PDC_TYPE_ILLEGAL;
43 
44 /* cell number and location (PAT firmware only) */
45 unsigned long parisc_cell_num __ro_after_init;
46 unsigned long parisc_cell_loc __ro_after_init;
47 unsigned long parisc_pat_pdc_cap __ro_after_init;
48 
49 
50 void __init setup_pdc(void)
51 {
52 	long status;
53 	unsigned int bus_id;
54 	struct pdc_system_map_mod_info module_result;
55 	struct pdc_module_path module_path;
56 	struct pdc_model model;
57 #ifdef CONFIG_64BIT
58 	struct pdc_pat_cell_num cell_info;
59 #endif
60 
61 	/* Determine the pdc "type" used on this machine */
62 
63 	printk(KERN_INFO "Determining PDC firmware type: ");
64 
65 	status = pdc_system_map_find_mods(&module_result, &module_path, 0);
66 	if (status == PDC_OK) {
67 		pdc_type = PDC_TYPE_SYSTEM_MAP;
68 		pr_cont("System Map.\n");
69 		return;
70 	}
71 
72 	/*
73 	 * If the machine doesn't support PDC_SYSTEM_MAP then either it
74 	 * is a pdc pat box, or it is an older box. All 64 bit capable
75 	 * machines are either pdc pat boxes or they support PDC_SYSTEM_MAP.
76 	 */
77 
78 	/*
79 	 * TODO: We should test for 64 bit capability and give a
80 	 * clearer message.
81 	 */
82 
83 #ifdef CONFIG_64BIT
84 	status = pdc_pat_cell_get_number(&cell_info);
85 	if (status == PDC_OK) {
86 		unsigned long legacy_rev, pat_rev;
87 		pdc_type = PDC_TYPE_PAT;
88 		pr_cont("64 bit PAT.\n");
89 		parisc_cell_num = cell_info.cell_num;
90 		parisc_cell_loc = cell_info.cell_loc;
91 		pr_info("PAT: Running on cell %lu and location %lu.\n",
92 			parisc_cell_num, parisc_cell_loc);
93 		status = pdc_pat_pd_get_pdc_revisions(&legacy_rev,
94 			&pat_rev, &parisc_pat_pdc_cap);
95 		pr_info("PAT: legacy revision 0x%lx, pat_rev 0x%lx, pdc_cap 0x%lx, S-PTLB %d, HPMC_RENDEZ %d.\n",
96 			legacy_rev, pat_rev, parisc_pat_pdc_cap,
97 			parisc_pat_pdc_cap
98 			 & PDC_PAT_CAPABILITY_BIT_SIMULTANEOUS_PTLB ? 1:0,
99 			parisc_pat_pdc_cap
100 			 & PDC_PAT_CAPABILITY_BIT_PDC_HPMC_RENDEZ   ? 1:0);
101 		return;
102 	}
103 #endif
104 
105 	/* Check the CPU's bus ID.  There's probably a better test.  */
106 
107 	status = pdc_model_info(&model);
108 
109 	bus_id = (model.hversion >> (4 + 7)) & 0x1f;
110 
111 	switch (bus_id) {
112 	case 0x4:		/* 720, 730, 750, 735, 755 */
113 	case 0x6:		/* 705, 710 */
114 	case 0x7:		/* 715, 725 */
115 	case 0x8:		/* 745, 747, 742 */
116 	case 0xA:		/* 712 and similar */
117 	case 0xC:		/* 715/64, at least */
118 
119 		pdc_type = PDC_TYPE_SNAKE;
120 		pr_cont("Snake.\n");
121 		return;
122 
123 	default:		/* Everything else */
124 
125 		pr_cont("Unsupported.\n");
126 		panic("If this is a 64-bit machine, please try a 64-bit kernel.\n");
127 	}
128 }
129 
130 #define PDC_PAGE_ADJ_SHIFT (PAGE_SHIFT - 12) /* pdc pages are always 4k */
131 
132 static void __init
133 set_pmem_entry(physmem_range_t *pmem_ptr, unsigned long start,
134 	       unsigned long pages4k)
135 {
136 	/* Rather than aligning and potentially throwing away
137 	 * memory, we'll assume that any ranges are already
138 	 * nicely aligned with any reasonable page size, and
139 	 * panic if they are not (it's more likely that the
140 	 * pdc info is bad in this case).
141 	 */
142 
143 	if (unlikely( ((start & (PAGE_SIZE - 1)) != 0)
144 	    || ((pages4k & ((1UL << PDC_PAGE_ADJ_SHIFT) - 1)) != 0) )) {
145 
146 		panic("Memory range doesn't align with page size!\n");
147 	}
148 
149 	pmem_ptr->start_pfn = (start >> PAGE_SHIFT);
150 	pmem_ptr->pages = (pages4k >> PDC_PAGE_ADJ_SHIFT);
151 }
152 
153 static void __init pagezero_memconfig(void)
154 {
155 	unsigned long npages;
156 
157 	/* Use the 32 bit information from page zero to create a single
158 	 * entry in the pmem_ranges[] table.
159 	 *
160 	 * We currently don't support machines with contiguous memory
161 	 * >= 4 Gb, who report that memory using 64 bit only fields
162 	 * on page zero. It's not worth doing until it can be tested,
163 	 * and it is not clear we can support those machines for other
164 	 * reasons.
165 	 *
166 	 * If that support is done in the future, this is where it
167 	 * should be done.
168 	 */
169 
170 	npages = (PAGE_ALIGN(PAGE0->imm_max_mem) >> PAGE_SHIFT);
171 	set_pmem_entry(pmem_ranges,0UL,npages);
172 	npmem_ranges = 1;
173 }
174 
175 #ifdef CONFIG_64BIT
176 
177 /* All of the PDC PAT specific code is 64-bit only */
178 
179 /*
180 **  The module object is filled via PDC_PAT_CELL[Return Cell Module].
181 **  If a module is found, register module will get the IODC bytes via
182 **  pdc_iodc_read() using the PA view of conf_base_addr for the hpa parameter.
183 **
184 **  The IO view can be used by PDC_PAT_CELL[Return Cell Module]
185 **  only for SBAs and LBAs.  This view will cause an invalid
186 **  argument error for all other cell module types.
187 **
188 */
189 
190 static int __init
191 pat_query_module(ulong pcell_loc, ulong mod_index)
192 {
193 	pdc_pat_cell_mod_maddr_block_t *pa_pdc_cell;
194 	unsigned long bytecnt;
195 	unsigned long temp;	/* 64-bit scratch value */
196 	long status;		/* PDC return value status */
197 	struct parisc_device *dev;
198 
199 	pa_pdc_cell = kmalloc(sizeof (*pa_pdc_cell), GFP_KERNEL);
200 	if (!pa_pdc_cell)
201 		panic("couldn't allocate memory for PDC_PAT_CELL!");
202 
203 	/* return cell module (PA or Processor view) */
204 	status = pdc_pat_cell_module(&bytecnt, pcell_loc, mod_index,
205 				     PA_VIEW, pa_pdc_cell);
206 
207 	if (status != PDC_OK) {
208 		/* no more cell modules or error */
209 		kfree(pa_pdc_cell);
210 		return status;
211 	}
212 
213 	temp = pa_pdc_cell->cba;
214 	dev = alloc_pa_dev(PAT_GET_CBA(temp), &(pa_pdc_cell->mod_path));
215 	if (!dev) {
216 		kfree(pa_pdc_cell);
217 		return PDC_OK;
218 	}
219 
220 	/* alloc_pa_dev sets dev->hpa */
221 
222 	/*
223 	** save parameters in the parisc_device
224 	** (The idea being the device driver will call pdc_pat_cell_module()
225 	** and store the results in its own data structure.)
226 	*/
227 	dev->pcell_loc = pcell_loc;
228 	dev->mod_index = mod_index;
229 
230 	/* save generic info returned from the call */
231 	/* REVISIT: who is the consumer of this? not sure yet... */
232 	dev->mod_info = pa_pdc_cell->mod_info;	/* pass to PAT_GET_ENTITY() */
233 	dev->pmod_loc = pa_pdc_cell->mod_location;
234 	dev->mod0 = pa_pdc_cell->mod[0];
235 
236 	register_parisc_device(dev);	/* advertise device */
237 
238 #ifdef DEBUG_PAT
239 	/* dump what we see so far... */
240 	switch (PAT_GET_ENTITY(dev->mod_info)) {
241 		pdc_pat_cell_mod_maddr_block_t io_pdc_cell;
242 		unsigned long i;
243 
244 	case PAT_ENTITY_PROC:
245 		printk(KERN_DEBUG "PAT_ENTITY_PROC: id_eid 0x%lx\n",
246 			pa_pdc_cell->mod[0]);
247 		break;
248 
249 	case PAT_ENTITY_MEM:
250 		printk(KERN_DEBUG
251 			"PAT_ENTITY_MEM: amount 0x%lx min_gni_base 0x%lx min_gni_len 0x%lx\n",
252 			pa_pdc_cell->mod[0], pa_pdc_cell->mod[1],
253 			pa_pdc_cell->mod[2]);
254 		break;
255 	case PAT_ENTITY_CA:
256 		printk(KERN_DEBUG "PAT_ENTITY_CA: %ld\n", pcell_loc);
257 		break;
258 
259 	case PAT_ENTITY_PBC:
260 		printk(KERN_DEBUG "PAT_ENTITY_PBC: ");
261 		goto print_ranges;
262 
263 	case PAT_ENTITY_SBA:
264 		printk(KERN_DEBUG "PAT_ENTITY_SBA: ");
265 		goto print_ranges;
266 
267 	case PAT_ENTITY_LBA:
268 		printk(KERN_DEBUG "PAT_ENTITY_LBA: ");
269 
270  print_ranges:
271 		pdc_pat_cell_module(&bytecnt, pcell_loc, mod_index,
272 				    IO_VIEW, &io_pdc_cell);
273 		printk(KERN_DEBUG "ranges %ld\n", pa_pdc_cell->mod[1]);
274 		for (i = 0; i < pa_pdc_cell->mod[1]; i++) {
275 			printk(KERN_DEBUG
276 				"  PA_VIEW %ld: 0x%016lx 0x%016lx 0x%016lx\n",
277 				i, pa_pdc_cell->mod[2 + i * 3],	/* type */
278 				pa_pdc_cell->mod[3 + i * 3],	/* start */
279 				pa_pdc_cell->mod[4 + i * 3]);	/* finish (ie end) */
280 			printk(KERN_DEBUG
281 				"  IO_VIEW %ld: 0x%016lx 0x%016lx 0x%016lx\n",
282 				i, io_pdc_cell.mod[2 + i * 3],	/* type */
283 				io_pdc_cell.mod[3 + i * 3],	/* start */
284 				io_pdc_cell.mod[4 + i * 3]);	/* finish (ie end) */
285 		}
286 		printk(KERN_DEBUG "\n");
287 		break;
288 	}
289 #endif /* DEBUG_PAT */
290 
291 	kfree(pa_pdc_cell);
292 
293 	return PDC_OK;
294 }
295 
296 
297 /* pat pdc can return information about a variety of different
298  * types of memory (e.g. firmware,i/o, etc) but we only care about
299  * the usable physical ram right now. Since the firmware specific
300  * information is allocated on the stack, we'll be generous, in
301  * case there is a lot of other information we don't care about.
302  */
303 
304 #define PAT_MAX_RANGES (4 * MAX_PHYSMEM_RANGES)
305 
306 static void __init pat_memconfig(void)
307 {
308 	unsigned long actual_len;
309 	struct pdc_pat_pd_addr_map_entry mem_table[PAT_MAX_RANGES+1];
310 	struct pdc_pat_pd_addr_map_entry *mtbl_ptr;
311 	physmem_range_t *pmem_ptr;
312 	long status;
313 	int entries;
314 	unsigned long length;
315 	int i;
316 
317 	length = (PAT_MAX_RANGES + 1) * sizeof(struct pdc_pat_pd_addr_map_entry);
318 
319 	status = pdc_pat_pd_get_addr_map(&actual_len, mem_table, length, 0L);
320 
321 	if ((status != PDC_OK)
322 	    || ((actual_len % sizeof(struct pdc_pat_pd_addr_map_entry)) != 0)) {
323 
324 		/* The above pdc call shouldn't fail, but, just in
325 		 * case, just use the PAGE0 info.
326 		 */
327 
328 		printk("\n\n\n");
329 		printk(KERN_WARNING "WARNING! Could not get full memory configuration. "
330 			"All memory may not be used!\n\n\n");
331 		pagezero_memconfig();
332 		return;
333 	}
334 
335 	entries = actual_len / sizeof(struct pdc_pat_pd_addr_map_entry);
336 
337 	if (entries > PAT_MAX_RANGES) {
338 		printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
339 		printk(KERN_WARNING "Some memory may not be used!\n");
340 	}
341 
342 	/* Copy information into the firmware independent pmem_ranges
343 	 * array, skipping types we don't care about. Notice we said
344 	 * "may" above. We'll use all the entries that were returned.
345 	 */
346 
347 	npmem_ranges = 0;
348 	mtbl_ptr = mem_table;
349 	pmem_ptr = pmem_ranges; /* Global firmware independent table */
350 	for (i = 0; i < entries; i++,mtbl_ptr++) {
351 		if (   (mtbl_ptr->entry_type != PAT_MEMORY_DESCRIPTOR)
352 		    || (mtbl_ptr->memory_type != PAT_MEMTYPE_MEMORY)
353 		    || (mtbl_ptr->pages == 0)
354 		    || (   (mtbl_ptr->memory_usage != PAT_MEMUSE_GENERAL)
355 			&& (mtbl_ptr->memory_usage != PAT_MEMUSE_GI)
356 			&& (mtbl_ptr->memory_usage != PAT_MEMUSE_GNI) ) ) {
357 
358 			continue;
359 		}
360 
361 		if (npmem_ranges == MAX_PHYSMEM_RANGES) {
362 			printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
363 			printk(KERN_WARNING "Some memory will not be used!\n");
364 			break;
365 		}
366 
367 		set_pmem_entry(pmem_ptr++,mtbl_ptr->paddr,mtbl_ptr->pages);
368 		npmem_ranges++;
369 	}
370 }
371 
372 static int __init pat_inventory(void)
373 {
374 	int status;
375 	ulong mod_index = 0;
376 	struct pdc_pat_cell_num cell_info;
377 
378 	/*
379 	** Note:  Prelude (and it's successors: Lclass, A400/500) only
380 	**        implement PDC_PAT_CELL sub-options 0 and 2.
381 	*/
382 	status = pdc_pat_cell_get_number(&cell_info);
383 	if (status != PDC_OK) {
384 		return 0;
385 	}
386 
387 #ifdef DEBUG_PAT
388 	printk(KERN_DEBUG "CELL_GET_NUMBER: 0x%lx 0x%lx\n", cell_info.cell_num,
389 	       cell_info.cell_loc);
390 #endif
391 
392 	while (PDC_OK == pat_query_module(cell_info.cell_loc, mod_index)) {
393 		mod_index++;
394 	}
395 
396 	return mod_index;
397 }
398 
399 /* We only look for extended memory ranges on a 64 bit capable box */
400 static void __init sprockets_memconfig(void)
401 {
402 	struct pdc_memory_table_raddr r_addr;
403 	struct pdc_memory_table mem_table[MAX_PHYSMEM_RANGES];
404 	struct pdc_memory_table *mtbl_ptr;
405 	physmem_range_t *pmem_ptr;
406 	long status;
407 	int entries;
408 	int i;
409 
410 	status = pdc_mem_mem_table(&r_addr,mem_table,
411 				(unsigned long)MAX_PHYSMEM_RANGES);
412 
413 	if (status != PDC_OK) {
414 
415 		/* The above pdc call only works on boxes with sprockets
416 		 * firmware (newer B,C,J class). Other non PAT PDC machines
417 		 * do support more than 3.75 Gb of memory, but we don't
418 		 * support them yet.
419 		 */
420 
421 		pagezero_memconfig();
422 		return;
423 	}
424 
425 	if (r_addr.entries_total > MAX_PHYSMEM_RANGES) {
426 		printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
427 		printk(KERN_WARNING "Some memory will not be used!\n");
428 	}
429 
430 	entries = (int)r_addr.entries_returned;
431 
432 	npmem_ranges = 0;
433 	mtbl_ptr = mem_table;
434 	pmem_ptr = pmem_ranges; /* Global firmware independent table */
435 	for (i = 0; i < entries; i++,mtbl_ptr++) {
436 		set_pmem_entry(pmem_ptr++,mtbl_ptr->paddr,mtbl_ptr->pages);
437 		npmem_ranges++;
438 	}
439 }
440 
441 #else   /* !CONFIG_64BIT */
442 
443 #define pat_inventory() do { } while (0)
444 #define pat_memconfig() do { } while (0)
445 #define sprockets_memconfig() pagezero_memconfig()
446 
447 #endif	/* !CONFIG_64BIT */
448 
449 
450 #ifndef CONFIG_PA20
451 
452 /* Code to support Snake machines (7[2350], 7[235]5, 715/Scorpio) */
453 
454 static struct parisc_device * __init
455 legacy_create_device(struct pdc_memory_map *r_addr,
456 		struct pdc_module_path *module_path)
457 {
458 	struct parisc_device *dev;
459 	int status = pdc_mem_map_hpa(r_addr, module_path);
460 	if (status != PDC_OK)
461 		return NULL;
462 
463 	dev = alloc_pa_dev(r_addr->hpa, &module_path->path);
464 	if (dev == NULL)
465 		return NULL;
466 
467 	register_parisc_device(dev);
468 	return dev;
469 }
470 
471 /**
472  * snake_inventory
473  *
474  * Before PDC_SYSTEM_MAP was invented, the PDC_MEM_MAP call was used.
475  * To use it, we initialise the mod_path.bc to 0xff and try all values of
476  * mod to get the HPA for the top-level devices.  Bus adapters may have
477  * sub-devices which are discovered by setting bc[5] to 0 and bc[4] to the
478  * module, then trying all possible functions.
479  */
480 static void __init snake_inventory(void)
481 {
482 	int mod;
483 	for (mod = 0; mod < 16; mod++) {
484 		struct parisc_device *dev;
485 		struct pdc_module_path module_path;
486 		struct pdc_memory_map r_addr;
487 		unsigned int func;
488 
489 		memset(module_path.path.bc, 0xff, 6);
490 		module_path.path.mod = mod;
491 		dev = legacy_create_device(&r_addr, &module_path);
492 		if ((!dev) || (dev->id.hw_type != HPHW_BA))
493 			continue;
494 
495 		memset(module_path.path.bc, 0xff, 4);
496 		module_path.path.bc[4] = mod;
497 
498 		for (func = 0; func < 16; func++) {
499 			module_path.path.bc[5] = 0;
500 			module_path.path.mod = func;
501 			legacy_create_device(&r_addr, &module_path);
502 		}
503 	}
504 }
505 
506 #else /* CONFIG_PA20 */
507 #define snake_inventory() do { } while (0)
508 #endif  /* CONFIG_PA20 */
509 
510 /* Common 32/64 bit based code goes here */
511 
512 /**
513  * add_system_map_addresses - Add additional addresses to the parisc device.
514  * @dev: The parisc device.
515  * @num_addrs: Then number of addresses to add;
516  * @module_instance: The system_map module instance.
517  *
518  * This function adds any additional addresses reported by the system_map
519  * firmware to the parisc device.
520  */
521 static void __init
522 add_system_map_addresses(struct parisc_device *dev, int num_addrs,
523 			 int module_instance)
524 {
525 	int i;
526 	long status;
527 	struct pdc_system_map_addr_info addr_result;
528 
529 	dev->addr = kmalloc_array(num_addrs, sizeof(*dev->addr), GFP_KERNEL);
530 	if(!dev->addr) {
531 		printk(KERN_ERR "%s %s(): memory allocation failure\n",
532 		       __FILE__, __func__);
533 		return;
534 	}
535 
536 	for(i = 1; i <= num_addrs; ++i) {
537 		status = pdc_system_map_find_addrs(&addr_result,
538 						   module_instance, i);
539 		if(PDC_OK == status) {
540 			dev->addr[dev->num_addrs] = (unsigned long)addr_result.mod_addr;
541 			dev->num_addrs++;
542 		} else {
543 			printk(KERN_WARNING
544 			       "Bad PDC_FIND_ADDRESS status return (%ld) for index %d\n",
545 			       status, i);
546 		}
547 	}
548 }
549 
550 /**
551  * system_map_inventory - Retrieve firmware devices via SYSTEM_MAP.
552  *
553  * This function attempts to retrieve and register all the devices firmware
554  * knows about via the SYSTEM_MAP PDC call.
555  */
556 static void __init system_map_inventory(void)
557 {
558 	int i;
559 	long status = PDC_OK;
560 
561 	for (i = 0; i < 256; i++) {
562 		struct parisc_device *dev;
563 		struct pdc_system_map_mod_info module_result;
564 		struct pdc_module_path module_path;
565 
566 		status = pdc_system_map_find_mods(&module_result,
567 				&module_path, i);
568 		if ((status == PDC_BAD_PROC) || (status == PDC_NE_MOD))
569 			break;
570 		if (status != PDC_OK)
571 			continue;
572 
573 		dev = alloc_pa_dev(module_result.mod_addr, &module_path.path);
574 		if (!dev)
575 			continue;
576 
577 		register_parisc_device(dev);
578 
579 		/* if available, get the additional addresses for a module */
580 		if (!module_result.add_addrs)
581 			continue;
582 
583 		add_system_map_addresses(dev, module_result.add_addrs, i);
584 	}
585 
586 	walk_central_bus();
587 	return;
588 }
589 
590 void __init do_memory_inventory(void)
591 {
592 	switch (pdc_type) {
593 
594 	case PDC_TYPE_PAT:
595 		pat_memconfig();
596 		break;
597 
598 	case PDC_TYPE_SYSTEM_MAP:
599 		sprockets_memconfig();
600 		break;
601 
602 	case PDC_TYPE_SNAKE:
603 		pagezero_memconfig();
604 		return;
605 
606 	default:
607 		panic("Unknown PDC type!\n");
608 	}
609 
610 	if (npmem_ranges == 0 || pmem_ranges[0].start_pfn != 0) {
611 		printk(KERN_WARNING "Bad memory configuration returned!\n");
612 		printk(KERN_WARNING "Some memory may not be used!\n");
613 		pagezero_memconfig();
614 	}
615 }
616 
617 void __init do_device_inventory(void)
618 {
619 	printk(KERN_INFO "Searching for devices...\n");
620 
621 	init_parisc_bus();
622 
623 	switch (pdc_type) {
624 
625 	case PDC_TYPE_PAT:
626 		pat_inventory();
627 		break;
628 
629 	case PDC_TYPE_SYSTEM_MAP:
630 		system_map_inventory();
631 		break;
632 
633 	case PDC_TYPE_SNAKE:
634 		snake_inventory();
635 		break;
636 
637 	default:
638 		panic("Unknown PDC type!\n");
639 	}
640 	printk(KERN_INFO "Found devices:\n");
641 	print_parisc_devices();
642 
643 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
644 	pa_serialize_tlb_flushes = machine_has_merced_bus();
645 	if (pa_serialize_tlb_flushes)
646 		pr_info("Merced bus found: Enable PxTLB serialization.\n");
647 #endif
648 }
649