xref: /linux/arch/parisc/kernel/inventory.c (revision 249ebf3f65f8530beb2cbfb91bff1d83ba88d23c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * inventory.c
4  *
5  * Copyright (c) 1999 The Puffin Group (David Kennedy and Alex deVries)
6  * Copyright (c) 2001 Matthew Wilcox for Hewlett-Packard
7  *
8  * These are the routines to discover what hardware exists in this box.
9  * This task is complicated by there being 3 different ways of
10  * performing an inventory, depending largely on the age of the box.
11  * The recommended way to do this is to check to see whether the machine
12  * is a `Snake' first, then try System Map, then try PAT.  We try System
13  * Map before checking for a Snake -- this probably doesn't cause any
14  * problems, but...
15  */
16 
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
21 #include <linux/mm.h>
22 #include <linux/platform_device.h>
23 #include <asm/hardware.h>
24 #include <asm/io.h>
25 #include <asm/mmzone.h>
26 #include <asm/pdc.h>
27 #include <asm/pdcpat.h>
28 #include <asm/processor.h>
29 #include <asm/page.h>
30 #include <asm/parisc-device.h>
31 #include <asm/tlbflush.h>
32 
33 /*
34 ** Debug options
35 ** DEBUG_PAT Dump details which PDC PAT provides about ranges/devices.
36 */
37 #undef DEBUG_PAT
38 
39 int pdc_type __ro_after_init = PDC_TYPE_ILLEGAL;
40 
41 /* cell number and location (PAT firmware only) */
42 unsigned long parisc_cell_num __ro_after_init;
43 unsigned long parisc_cell_loc __ro_after_init;
44 unsigned long parisc_pat_pdc_cap __ro_after_init;
45 
46 
47 void __init setup_pdc(void)
48 {
49 	long status;
50 	unsigned int bus_id;
51 	struct pdc_system_map_mod_info module_result;
52 	struct pdc_module_path module_path;
53 	struct pdc_model model;
54 #ifdef CONFIG_64BIT
55 	struct pdc_pat_cell_num cell_info;
56 #endif
57 
58 	/* Determine the pdc "type" used on this machine */
59 
60 	printk(KERN_INFO "Determining PDC firmware type: ");
61 
62 	status = pdc_system_map_find_mods(&module_result, &module_path, 0);
63 	if (status == PDC_OK) {
64 		pdc_type = PDC_TYPE_SYSTEM_MAP;
65 		pr_cont("System Map.\n");
66 		return;
67 	}
68 
69 	/*
70 	 * If the machine doesn't support PDC_SYSTEM_MAP then either it
71 	 * is a pdc pat box, or it is an older box. All 64 bit capable
72 	 * machines are either pdc pat boxes or they support PDC_SYSTEM_MAP.
73 	 */
74 
75 	/*
76 	 * TODO: We should test for 64 bit capability and give a
77 	 * clearer message.
78 	 */
79 
80 #ifdef CONFIG_64BIT
81 	status = pdc_pat_cell_get_number(&cell_info);
82 	if (status == PDC_OK) {
83 		unsigned long legacy_rev, pat_rev;
84 		pdc_type = PDC_TYPE_PAT;
85 		pr_cont("64 bit PAT.\n");
86 		parisc_cell_num = cell_info.cell_num;
87 		parisc_cell_loc = cell_info.cell_loc;
88 		pr_info("PAT: Running on cell %lu and location %lu.\n",
89 			parisc_cell_num, parisc_cell_loc);
90 		status = pdc_pat_pd_get_pdc_revisions(&legacy_rev,
91 			&pat_rev, &parisc_pat_pdc_cap);
92 		pr_info("PAT: legacy revision 0x%lx, pat_rev 0x%lx, pdc_cap 0x%lx, S-PTLB %d, HPMC_RENDEZ %d.\n",
93 			legacy_rev, pat_rev, parisc_pat_pdc_cap,
94 			parisc_pat_pdc_cap
95 			 & PDC_PAT_CAPABILITY_BIT_SIMULTANEOUS_PTLB ? 1:0,
96 			parisc_pat_pdc_cap
97 			 & PDC_PAT_CAPABILITY_BIT_PDC_HPMC_RENDEZ   ? 1:0);
98 		return;
99 	}
100 #endif
101 
102 	/* Check the CPU's bus ID.  There's probably a better test.  */
103 
104 	status = pdc_model_info(&model);
105 
106 	bus_id = (model.hversion >> (4 + 7)) & 0x1f;
107 
108 	switch (bus_id) {
109 	case 0x4:		/* 720, 730, 750, 735, 755 */
110 	case 0x6:		/* 705, 710 */
111 	case 0x7:		/* 715, 725 */
112 	case 0x8:		/* 745, 747, 742 */
113 	case 0xA:		/* 712 and similar */
114 	case 0xC:		/* 715/64, at least */
115 
116 		pdc_type = PDC_TYPE_SNAKE;
117 		pr_cont("Snake.\n");
118 		return;
119 
120 	default:		/* Everything else */
121 
122 		pr_cont("Unsupported.\n");
123 		panic("If this is a 64-bit machine, please try a 64-bit kernel.\n");
124 	}
125 }
126 
127 #define PDC_PAGE_ADJ_SHIFT (PAGE_SHIFT - 12) /* pdc pages are always 4k */
128 
129 static void __init
130 set_pmem_entry(physmem_range_t *pmem_ptr, unsigned long start,
131 	       unsigned long pages4k)
132 {
133 	/* Rather than aligning and potentially throwing away
134 	 * memory, we'll assume that any ranges are already
135 	 * nicely aligned with any reasonable page size, and
136 	 * panic if they are not (it's more likely that the
137 	 * pdc info is bad in this case).
138 	 */
139 
140 	if (unlikely( ((start & (PAGE_SIZE - 1)) != 0)
141 	    || ((pages4k & ((1UL << PDC_PAGE_ADJ_SHIFT) - 1)) != 0) )) {
142 
143 		panic("Memory range doesn't align with page size!\n");
144 	}
145 
146 	pmem_ptr->start_pfn = (start >> PAGE_SHIFT);
147 	pmem_ptr->pages = (pages4k >> PDC_PAGE_ADJ_SHIFT);
148 }
149 
150 static void __init pagezero_memconfig(void)
151 {
152 	unsigned long npages;
153 
154 	/* Use the 32 bit information from page zero to create a single
155 	 * entry in the pmem_ranges[] table.
156 	 *
157 	 * We currently don't support machines with contiguous memory
158 	 * >= 4 Gb, who report that memory using 64 bit only fields
159 	 * on page zero. It's not worth doing until it can be tested,
160 	 * and it is not clear we can support those machines for other
161 	 * reasons.
162 	 *
163 	 * If that support is done in the future, this is where it
164 	 * should be done.
165 	 */
166 
167 	npages = (PAGE_ALIGN(PAGE0->imm_max_mem) >> PAGE_SHIFT);
168 	set_pmem_entry(pmem_ranges,0UL,npages);
169 	npmem_ranges = 1;
170 }
171 
172 #ifdef CONFIG_64BIT
173 
174 /* All of the PDC PAT specific code is 64-bit only */
175 
176 /*
177 **  The module object is filled via PDC_PAT_CELL[Return Cell Module].
178 **  If a module is found, register module will get the IODC bytes via
179 **  pdc_iodc_read() using the PA view of conf_base_addr for the hpa parameter.
180 **
181 **  The IO view can be used by PDC_PAT_CELL[Return Cell Module]
182 **  only for SBAs and LBAs.  This view will cause an invalid
183 **  argument error for all other cell module types.
184 **
185 */
186 
187 static int __init
188 pat_query_module(ulong pcell_loc, ulong mod_index)
189 {
190 	pdc_pat_cell_mod_maddr_block_t *pa_pdc_cell;
191 	unsigned long bytecnt;
192 	unsigned long temp;	/* 64-bit scratch value */
193 	long status;		/* PDC return value status */
194 	struct parisc_device *dev;
195 
196 	pa_pdc_cell = kmalloc(sizeof (*pa_pdc_cell), GFP_KERNEL);
197 	if (!pa_pdc_cell)
198 		panic("couldn't allocate memory for PDC_PAT_CELL!");
199 
200 	/* return cell module (PA or Processor view) */
201 	status = pdc_pat_cell_module(&bytecnt, pcell_loc, mod_index,
202 				     PA_VIEW, pa_pdc_cell);
203 
204 	if (status != PDC_OK) {
205 		/* no more cell modules or error */
206 		kfree(pa_pdc_cell);
207 		return status;
208 	}
209 
210 	temp = pa_pdc_cell->cba;
211 	dev = alloc_pa_dev(PAT_GET_CBA(temp), &(pa_pdc_cell->mod_path));
212 	if (!dev) {
213 		kfree(pa_pdc_cell);
214 		return PDC_OK;
215 	}
216 
217 	/* alloc_pa_dev sets dev->hpa */
218 
219 	/*
220 	** save parameters in the parisc_device
221 	** (The idea being the device driver will call pdc_pat_cell_module()
222 	** and store the results in its own data structure.)
223 	*/
224 	dev->pcell_loc = pcell_loc;
225 	dev->mod_index = mod_index;
226 
227 	/* save generic info returned from the call */
228 	/* REVISIT: who is the consumer of this? not sure yet... */
229 	dev->mod_info = pa_pdc_cell->mod_info;	/* pass to PAT_GET_ENTITY() */
230 	dev->pmod_loc = pa_pdc_cell->mod_location;
231 	dev->mod0 = pa_pdc_cell->mod[0];
232 
233 	register_parisc_device(dev);	/* advertise device */
234 
235 #ifdef DEBUG_PAT
236 	/* dump what we see so far... */
237 	switch (PAT_GET_ENTITY(dev->mod_info)) {
238 		pdc_pat_cell_mod_maddr_block_t io_pdc_cell;
239 		unsigned long i;
240 
241 	case PAT_ENTITY_PROC:
242 		printk(KERN_DEBUG "PAT_ENTITY_PROC: id_eid 0x%lx\n",
243 			pa_pdc_cell->mod[0]);
244 		break;
245 
246 	case PAT_ENTITY_MEM:
247 		printk(KERN_DEBUG
248 			"PAT_ENTITY_MEM: amount 0x%lx min_gni_base 0x%lx min_gni_len 0x%lx\n",
249 			pa_pdc_cell->mod[0], pa_pdc_cell->mod[1],
250 			pa_pdc_cell->mod[2]);
251 		break;
252 	case PAT_ENTITY_CA:
253 		printk(KERN_DEBUG "PAT_ENTITY_CA: %ld\n", pcell_loc);
254 		break;
255 
256 	case PAT_ENTITY_PBC:
257 		printk(KERN_DEBUG "PAT_ENTITY_PBC: ");
258 		goto print_ranges;
259 
260 	case PAT_ENTITY_SBA:
261 		printk(KERN_DEBUG "PAT_ENTITY_SBA: ");
262 		goto print_ranges;
263 
264 	case PAT_ENTITY_LBA:
265 		printk(KERN_DEBUG "PAT_ENTITY_LBA: ");
266 
267  print_ranges:
268 		pdc_pat_cell_module(&bytecnt, pcell_loc, mod_index,
269 				    IO_VIEW, &io_pdc_cell);
270 		printk(KERN_DEBUG "ranges %ld\n", pa_pdc_cell->mod[1]);
271 		for (i = 0; i < pa_pdc_cell->mod[1]; i++) {
272 			printk(KERN_DEBUG
273 				"  PA_VIEW %ld: 0x%016lx 0x%016lx 0x%016lx\n",
274 				i, pa_pdc_cell->mod[2 + i * 3],	/* type */
275 				pa_pdc_cell->mod[3 + i * 3],	/* start */
276 				pa_pdc_cell->mod[4 + i * 3]);	/* finish (ie end) */
277 			printk(KERN_DEBUG
278 				"  IO_VIEW %ld: 0x%016lx 0x%016lx 0x%016lx\n",
279 				i, io_pdc_cell.mod[2 + i * 3],	/* type */
280 				io_pdc_cell.mod[3 + i * 3],	/* start */
281 				io_pdc_cell.mod[4 + i * 3]);	/* finish (ie end) */
282 		}
283 		printk(KERN_DEBUG "\n");
284 		break;
285 	}
286 #endif /* DEBUG_PAT */
287 
288 	kfree(pa_pdc_cell);
289 
290 	return PDC_OK;
291 }
292 
293 
294 /* pat pdc can return information about a variety of different
295  * types of memory (e.g. firmware,i/o, etc) but we only care about
296  * the usable physical ram right now. Since the firmware specific
297  * information is allocated on the stack, we'll be generous, in
298  * case there is a lot of other information we don't care about.
299  */
300 
301 #define PAT_MAX_RANGES (4 * MAX_PHYSMEM_RANGES)
302 
303 static void __init pat_memconfig(void)
304 {
305 	unsigned long actual_len;
306 	struct pdc_pat_pd_addr_map_entry mem_table[PAT_MAX_RANGES+1];
307 	struct pdc_pat_pd_addr_map_entry *mtbl_ptr;
308 	physmem_range_t *pmem_ptr;
309 	long status;
310 	int entries;
311 	unsigned long length;
312 	int i;
313 
314 	length = (PAT_MAX_RANGES + 1) * sizeof(struct pdc_pat_pd_addr_map_entry);
315 
316 	status = pdc_pat_pd_get_addr_map(&actual_len, mem_table, length, 0L);
317 
318 	if ((status != PDC_OK)
319 	    || ((actual_len % sizeof(struct pdc_pat_pd_addr_map_entry)) != 0)) {
320 
321 		/* The above pdc call shouldn't fail, but, just in
322 		 * case, just use the PAGE0 info.
323 		 */
324 
325 		printk("\n\n\n");
326 		printk(KERN_WARNING "WARNING! Could not get full memory configuration. "
327 			"All memory may not be used!\n\n\n");
328 		pagezero_memconfig();
329 		return;
330 	}
331 
332 	entries = actual_len / sizeof(struct pdc_pat_pd_addr_map_entry);
333 
334 	if (entries > PAT_MAX_RANGES) {
335 		printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
336 		printk(KERN_WARNING "Some memory may not be used!\n");
337 	}
338 
339 	/* Copy information into the firmware independent pmem_ranges
340 	 * array, skipping types we don't care about. Notice we said
341 	 * "may" above. We'll use all the entries that were returned.
342 	 */
343 
344 	npmem_ranges = 0;
345 	mtbl_ptr = mem_table;
346 	pmem_ptr = pmem_ranges; /* Global firmware independent table */
347 	for (i = 0; i < entries; i++,mtbl_ptr++) {
348 		if (   (mtbl_ptr->entry_type != PAT_MEMORY_DESCRIPTOR)
349 		    || (mtbl_ptr->memory_type != PAT_MEMTYPE_MEMORY)
350 		    || (mtbl_ptr->pages == 0)
351 		    || (   (mtbl_ptr->memory_usage != PAT_MEMUSE_GENERAL)
352 			&& (mtbl_ptr->memory_usage != PAT_MEMUSE_GI)
353 			&& (mtbl_ptr->memory_usage != PAT_MEMUSE_GNI) ) ) {
354 
355 			continue;
356 		}
357 
358 		if (npmem_ranges == MAX_PHYSMEM_RANGES) {
359 			printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
360 			printk(KERN_WARNING "Some memory will not be used!\n");
361 			break;
362 		}
363 
364 		set_pmem_entry(pmem_ptr++,mtbl_ptr->paddr,mtbl_ptr->pages);
365 		npmem_ranges++;
366 	}
367 }
368 
369 static int __init pat_inventory(void)
370 {
371 	int status;
372 	ulong mod_index = 0;
373 	struct pdc_pat_cell_num cell_info;
374 
375 	/*
376 	** Note:  Prelude (and it's successors: Lclass, A400/500) only
377 	**        implement PDC_PAT_CELL sub-options 0 and 2.
378 	*/
379 	status = pdc_pat_cell_get_number(&cell_info);
380 	if (status != PDC_OK) {
381 		return 0;
382 	}
383 
384 #ifdef DEBUG_PAT
385 	printk(KERN_DEBUG "CELL_GET_NUMBER: 0x%lx 0x%lx\n", cell_info.cell_num,
386 	       cell_info.cell_loc);
387 #endif
388 
389 	while (PDC_OK == pat_query_module(cell_info.cell_loc, mod_index)) {
390 		mod_index++;
391 	}
392 
393 	return mod_index;
394 }
395 
396 /* We only look for extended memory ranges on a 64 bit capable box */
397 static void __init sprockets_memconfig(void)
398 {
399 	struct pdc_memory_table_raddr r_addr;
400 	struct pdc_memory_table mem_table[MAX_PHYSMEM_RANGES];
401 	struct pdc_memory_table *mtbl_ptr;
402 	physmem_range_t *pmem_ptr;
403 	long status;
404 	int entries;
405 	int i;
406 
407 	status = pdc_mem_mem_table(&r_addr,mem_table,
408 				(unsigned long)MAX_PHYSMEM_RANGES);
409 
410 	if (status != PDC_OK) {
411 
412 		/* The above pdc call only works on boxes with sprockets
413 		 * firmware (newer B,C,J class). Other non PAT PDC machines
414 		 * do support more than 3.75 Gb of memory, but we don't
415 		 * support them yet.
416 		 */
417 
418 		pagezero_memconfig();
419 		return;
420 	}
421 
422 	if (r_addr.entries_total > MAX_PHYSMEM_RANGES) {
423 		printk(KERN_WARNING "This Machine has more memory ranges than we support!\n");
424 		printk(KERN_WARNING "Some memory will not be used!\n");
425 	}
426 
427 	entries = (int)r_addr.entries_returned;
428 
429 	npmem_ranges = 0;
430 	mtbl_ptr = mem_table;
431 	pmem_ptr = pmem_ranges; /* Global firmware independent table */
432 	for (i = 0; i < entries; i++,mtbl_ptr++) {
433 		set_pmem_entry(pmem_ptr++,mtbl_ptr->paddr,mtbl_ptr->pages);
434 		npmem_ranges++;
435 	}
436 }
437 
438 #else   /* !CONFIG_64BIT */
439 
440 #define pat_inventory() do { } while (0)
441 #define pat_memconfig() do { } while (0)
442 #define sprockets_memconfig() pagezero_memconfig()
443 
444 #endif	/* !CONFIG_64BIT */
445 
446 
447 #ifndef CONFIG_PA20
448 
449 /* Code to support Snake machines (7[2350], 7[235]5, 715/Scorpio) */
450 
451 static struct parisc_device * __init
452 legacy_create_device(struct pdc_memory_map *r_addr,
453 		struct pdc_module_path *module_path)
454 {
455 	struct parisc_device *dev;
456 	int status = pdc_mem_map_hpa(r_addr, module_path);
457 	if (status != PDC_OK)
458 		return NULL;
459 
460 	dev = alloc_pa_dev(r_addr->hpa, &module_path->path);
461 	if (dev == NULL)
462 		return NULL;
463 
464 	register_parisc_device(dev);
465 	return dev;
466 }
467 
468 /**
469  * snake_inventory
470  *
471  * Before PDC_SYSTEM_MAP was invented, the PDC_MEM_MAP call was used.
472  * To use it, we initialise the mod_path.bc to 0xff and try all values of
473  * mod to get the HPA for the top-level devices.  Bus adapters may have
474  * sub-devices which are discovered by setting bc[5] to 0 and bc[4] to the
475  * module, then trying all possible functions.
476  */
477 static void __init snake_inventory(void)
478 {
479 	int mod;
480 	for (mod = 0; mod < 16; mod++) {
481 		struct parisc_device *dev;
482 		struct pdc_module_path module_path;
483 		struct pdc_memory_map r_addr;
484 		unsigned int func;
485 
486 		memset(module_path.path.bc, 0xff, 6);
487 		module_path.path.mod = mod;
488 		dev = legacy_create_device(&r_addr, &module_path);
489 		if ((!dev) || (dev->id.hw_type != HPHW_BA))
490 			continue;
491 
492 		memset(module_path.path.bc, 0xff, 4);
493 		module_path.path.bc[4] = mod;
494 
495 		for (func = 0; func < 16; func++) {
496 			module_path.path.bc[5] = 0;
497 			module_path.path.mod = func;
498 			legacy_create_device(&r_addr, &module_path);
499 		}
500 	}
501 }
502 
503 #else /* CONFIG_PA20 */
504 #define snake_inventory() do { } while (0)
505 #endif  /* CONFIG_PA20 */
506 
507 /* Common 32/64 bit based code goes here */
508 
509 /**
510  * add_system_map_addresses - Add additional addresses to the parisc device.
511  * @dev: The parisc device.
512  * @num_addrs: Then number of addresses to add;
513  * @module_instance: The system_map module instance.
514  *
515  * This function adds any additional addresses reported by the system_map
516  * firmware to the parisc device.
517  */
518 static void __init
519 add_system_map_addresses(struct parisc_device *dev, int num_addrs,
520 			 int module_instance)
521 {
522 	int i;
523 	long status;
524 	struct pdc_system_map_addr_info addr_result;
525 
526 	dev->addr = kmalloc_array(num_addrs, sizeof(*dev->addr), GFP_KERNEL);
527 	if(!dev->addr) {
528 		printk(KERN_ERR "%s %s(): memory allocation failure\n",
529 		       __FILE__, __func__);
530 		return;
531 	}
532 
533 	for(i = 1; i <= num_addrs; ++i) {
534 		status = pdc_system_map_find_addrs(&addr_result,
535 						   module_instance, i);
536 		if(PDC_OK == status) {
537 			dev->addr[dev->num_addrs] = (unsigned long)addr_result.mod_addr;
538 			dev->num_addrs++;
539 		} else {
540 			printk(KERN_WARNING
541 			       "Bad PDC_FIND_ADDRESS status return (%ld) for index %d\n",
542 			       status, i);
543 		}
544 	}
545 }
546 
547 /**
548  * system_map_inventory - Retrieve firmware devices via SYSTEM_MAP.
549  *
550  * This function attempts to retrieve and register all the devices firmware
551  * knows about via the SYSTEM_MAP PDC call.
552  */
553 static void __init system_map_inventory(void)
554 {
555 	int i;
556 	long status = PDC_OK;
557 
558 	for (i = 0; i < 256; i++) {
559 		struct parisc_device *dev;
560 		struct pdc_system_map_mod_info module_result;
561 		struct pdc_module_path module_path;
562 
563 		status = pdc_system_map_find_mods(&module_result,
564 				&module_path, i);
565 		if ((status == PDC_BAD_PROC) || (status == PDC_NE_MOD))
566 			break;
567 		if (status != PDC_OK)
568 			continue;
569 
570 		dev = alloc_pa_dev(module_result.mod_addr, &module_path.path);
571 		if (!dev)
572 			continue;
573 
574 		register_parisc_device(dev);
575 
576 		/* if available, get the additional addresses for a module */
577 		if (!module_result.add_addrs)
578 			continue;
579 
580 		add_system_map_addresses(dev, module_result.add_addrs, i);
581 	}
582 
583 	walk_central_bus();
584 	return;
585 }
586 
587 void __init do_memory_inventory(void)
588 {
589 	switch (pdc_type) {
590 
591 	case PDC_TYPE_PAT:
592 		pat_memconfig();
593 		break;
594 
595 	case PDC_TYPE_SYSTEM_MAP:
596 		sprockets_memconfig();
597 		break;
598 
599 	case PDC_TYPE_SNAKE:
600 		pagezero_memconfig();
601 		return;
602 
603 	default:
604 		panic("Unknown PDC type!\n");
605 	}
606 
607 	if (npmem_ranges == 0 || pmem_ranges[0].start_pfn != 0) {
608 		printk(KERN_WARNING "Bad memory configuration returned!\n");
609 		printk(KERN_WARNING "Some memory may not be used!\n");
610 		pagezero_memconfig();
611 	}
612 }
613 
614 void __init do_device_inventory(void)
615 {
616 	printk(KERN_INFO "Searching for devices...\n");
617 
618 	init_parisc_bus();
619 
620 	switch (pdc_type) {
621 
622 	case PDC_TYPE_PAT:
623 		pat_inventory();
624 		break;
625 
626 	case PDC_TYPE_SYSTEM_MAP:
627 		system_map_inventory();
628 		break;
629 
630 	case PDC_TYPE_SNAKE:
631 		snake_inventory();
632 		break;
633 
634 	default:
635 		panic("Unknown PDC type!\n");
636 	}
637 	printk(KERN_INFO "Found devices:\n");
638 	print_parisc_devices();
639 
640 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
641 	pa_serialize_tlb_flushes = machine_has_merced_bus();
642 	if (pa_serialize_tlb_flushes)
643 		pr_info("Merced bus found: Enable PxTLB serialization.\n");
644 #endif
645 
646 #if defined(CONFIG_FW_CFG_SYSFS)
647 	if (running_on_qemu) {
648 		struct resource res[3] = {0,};
649 		unsigned int base;
650 
651 		base = ((unsigned long long) PAGE0->pad0[2] << 32)
652 			| PAGE0->pad0[3]; /* SeaBIOS stored it here */
653 
654 		res[0].name = "fw_cfg";
655 		res[0].start = base;
656 		res[0].end = base + 8 - 1;
657 		res[0].flags = IORESOURCE_MEM;
658 
659 		res[1].name = "ctrl";
660 		res[1].start = 0;
661 		res[1].flags = IORESOURCE_REG;
662 
663 		res[2].name = "data";
664 		res[2].start = 4;
665 		res[2].flags = IORESOURCE_REG;
666 
667 		if (base) {
668 			pr_info("Found qemu fw_cfg interface at %#08x\n", base);
669 			platform_device_register_simple("fw_cfg",
670 				PLATFORM_DEVID_NONE, res, 3);
671 		}
672 	}
673 #endif
674 }
675