xref: /linux/arch/parisc/mm/init.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  *  linux/arch/parisc/mm/init.c
3  *
4  *  Copyright (C) 1995	Linus Torvalds
5  *  Copyright 1999 SuSE GmbH
6  *    changed by Philipp Rumpf
7  *  Copyright 1999 Philipp Rumpf (prumpf@tux.org)
8  *  Copyright 2004 Randolph Chung (tausq@debian.org)
9  *  Copyright 2006 Helge Deller (deller@gmx.de)
10  *
11  */
12 
13 #include <linux/config.h>
14 
15 #include <linux/module.h>
16 #include <linux/mm.h>
17 #include <linux/bootmem.h>
18 #include <linux/delay.h>
19 #include <linux/init.h>
20 #include <linux/pci.h>		/* for hppa_dma_ops and pcxl_dma_ops */
21 #include <linux/initrd.h>
22 #include <linux/swap.h>
23 #include <linux/unistd.h>
24 #include <linux/nodemask.h>	/* for node_online_map */
25 #include <linux/pagemap.h>	/* for release_pages and page_cache_release */
26 
27 #include <asm/pgalloc.h>
28 #include <asm/tlb.h>
29 #include <asm/pdc_chassis.h>
30 #include <asm/mmzone.h>
31 
32 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
33 
34 extern char _text;	/* start of kernel code, defined by linker */
35 extern int  data_start;
36 extern char _end;	/* end of BSS, defined by linker */
37 extern char __init_begin, __init_end;
38 
39 #ifdef CONFIG_DISCONTIGMEM
40 struct node_map_data node_data[MAX_NUMNODES] __read_mostly;
41 bootmem_data_t bmem_data[MAX_NUMNODES] __read_mostly;
42 unsigned char pfnnid_map[PFNNID_MAP_MAX] __read_mostly;
43 #endif
44 
45 static struct resource data_resource = {
46 	.name	= "Kernel data",
47 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
48 };
49 
50 static struct resource code_resource = {
51 	.name	= "Kernel code",
52 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
53 };
54 
55 static struct resource pdcdata_resource = {
56 	.name	= "PDC data (Page Zero)",
57 	.start	= 0,
58 	.end	= 0x9ff,
59 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
60 };
61 
62 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __read_mostly;
63 
64 /* The following array is initialized from the firmware specific
65  * information retrieved in kernel/inventory.c.
66  */
67 
68 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __read_mostly;
69 int npmem_ranges __read_mostly;
70 
71 #ifdef __LP64__
72 #define MAX_MEM         (~0UL)
73 #else /* !__LP64__ */
74 #define MAX_MEM         (3584U*1024U*1024U)
75 #endif /* !__LP64__ */
76 
77 static unsigned long mem_limit __read_mostly = MAX_MEM;
78 
79 static void __init mem_limit_func(void)
80 {
81 	char *cp, *end;
82 	unsigned long limit;
83 	extern char saved_command_line[];
84 
85 	/* We need this before __setup() functions are called */
86 
87 	limit = MAX_MEM;
88 	for (cp = saved_command_line; *cp; ) {
89 		if (memcmp(cp, "mem=", 4) == 0) {
90 			cp += 4;
91 			limit = memparse(cp, &end);
92 			if (end != cp)
93 				break;
94 			cp = end;
95 		} else {
96 			while (*cp != ' ' && *cp)
97 				++cp;
98 			while (*cp == ' ')
99 				++cp;
100 		}
101 	}
102 
103 	if (limit < mem_limit)
104 		mem_limit = limit;
105 }
106 
107 #define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
108 
109 static void __init setup_bootmem(void)
110 {
111 	unsigned long bootmap_size;
112 	unsigned long mem_max;
113 	unsigned long bootmap_pages;
114 	unsigned long bootmap_start_pfn;
115 	unsigned long bootmap_pfn;
116 #ifndef CONFIG_DISCONTIGMEM
117 	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
118 	int npmem_holes;
119 #endif
120 	int i, sysram_resource_count;
121 
122 	disable_sr_hashing(); /* Turn off space register hashing */
123 
124 	/*
125 	 * Sort the ranges. Since the number of ranges is typically
126 	 * small, and performance is not an issue here, just do
127 	 * a simple insertion sort.
128 	 */
129 
130 	for (i = 1; i < npmem_ranges; i++) {
131 		int j;
132 
133 		for (j = i; j > 0; j--) {
134 			unsigned long tmp;
135 
136 			if (pmem_ranges[j-1].start_pfn <
137 			    pmem_ranges[j].start_pfn) {
138 
139 				break;
140 			}
141 			tmp = pmem_ranges[j-1].start_pfn;
142 			pmem_ranges[j-1].start_pfn = pmem_ranges[j].start_pfn;
143 			pmem_ranges[j].start_pfn = tmp;
144 			tmp = pmem_ranges[j-1].pages;
145 			pmem_ranges[j-1].pages = pmem_ranges[j].pages;
146 			pmem_ranges[j].pages = tmp;
147 		}
148 	}
149 
150 #ifndef CONFIG_DISCONTIGMEM
151 	/*
152 	 * Throw out ranges that are too far apart (controlled by
153 	 * MAX_GAP).
154 	 */
155 
156 	for (i = 1; i < npmem_ranges; i++) {
157 		if (pmem_ranges[i].start_pfn -
158 			(pmem_ranges[i-1].start_pfn +
159 			 pmem_ranges[i-1].pages) > MAX_GAP) {
160 			npmem_ranges = i;
161 			printk("Large gap in memory detected (%ld pages). "
162 			       "Consider turning on CONFIG_DISCONTIGMEM\n",
163 			       pmem_ranges[i].start_pfn -
164 			       (pmem_ranges[i-1].start_pfn +
165 			        pmem_ranges[i-1].pages));
166 			break;
167 		}
168 	}
169 #endif
170 
171 	if (npmem_ranges > 1) {
172 
173 		/* Print the memory ranges */
174 
175 		printk(KERN_INFO "Memory Ranges:\n");
176 
177 		for (i = 0; i < npmem_ranges; i++) {
178 			unsigned long start;
179 			unsigned long size;
180 
181 			size = (pmem_ranges[i].pages << PAGE_SHIFT);
182 			start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
183 			printk(KERN_INFO "%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
184 				i,start, start + (size - 1), size >> 20);
185 		}
186 	}
187 
188 	sysram_resource_count = npmem_ranges;
189 	for (i = 0; i < sysram_resource_count; i++) {
190 		struct resource *res = &sysram_resources[i];
191 		res->name = "System RAM";
192 		res->start = pmem_ranges[i].start_pfn << PAGE_SHIFT;
193 		res->end = res->start + (pmem_ranges[i].pages << PAGE_SHIFT)-1;
194 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
195 		request_resource(&iomem_resource, res);
196 	}
197 
198 	/*
199 	 * For 32 bit kernels we limit the amount of memory we can
200 	 * support, in order to preserve enough kernel address space
201 	 * for other purposes. For 64 bit kernels we don't normally
202 	 * limit the memory, but this mechanism can be used to
203 	 * artificially limit the amount of memory (and it is written
204 	 * to work with multiple memory ranges).
205 	 */
206 
207 	mem_limit_func();       /* check for "mem=" argument */
208 
209 	mem_max = 0;
210 	num_physpages = 0;
211 	for (i = 0; i < npmem_ranges; i++) {
212 		unsigned long rsize;
213 
214 		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
215 		if ((mem_max + rsize) > mem_limit) {
216 			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
217 			if (mem_max == mem_limit)
218 				npmem_ranges = i;
219 			else {
220 				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
221 						       - (mem_max >> PAGE_SHIFT);
222 				npmem_ranges = i + 1;
223 				mem_max = mem_limit;
224 			}
225 	        num_physpages += pmem_ranges[i].pages;
226 			break;
227 		}
228 	    num_physpages += pmem_ranges[i].pages;
229 		mem_max += rsize;
230 	}
231 
232 	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
233 
234 #ifndef CONFIG_DISCONTIGMEM
235 	/* Merge the ranges, keeping track of the holes */
236 
237 	{
238 		unsigned long end_pfn;
239 		unsigned long hole_pages;
240 
241 		npmem_holes = 0;
242 		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
243 		for (i = 1; i < npmem_ranges; i++) {
244 
245 			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
246 			if (hole_pages) {
247 				pmem_holes[npmem_holes].start_pfn = end_pfn;
248 				pmem_holes[npmem_holes++].pages = hole_pages;
249 				end_pfn += hole_pages;
250 			}
251 			end_pfn += pmem_ranges[i].pages;
252 		}
253 
254 		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
255 		npmem_ranges = 1;
256 	}
257 #endif
258 
259 	bootmap_pages = 0;
260 	for (i = 0; i < npmem_ranges; i++)
261 		bootmap_pages += bootmem_bootmap_pages(pmem_ranges[i].pages);
262 
263 	bootmap_start_pfn = PAGE_ALIGN(__pa((unsigned long) &_end)) >> PAGE_SHIFT;
264 
265 #ifdef CONFIG_DISCONTIGMEM
266 	for (i = 0; i < MAX_PHYSMEM_RANGES; i++) {
267 		memset(NODE_DATA(i), 0, sizeof(pg_data_t));
268 		NODE_DATA(i)->bdata = &bmem_data[i];
269 	}
270 	memset(pfnnid_map, 0xff, sizeof(pfnnid_map));
271 
272 	for (i = 0; i < npmem_ranges; i++)
273 		node_set_online(i);
274 #endif
275 
276 	/*
277 	 * Initialize and free the full range of memory in each range.
278 	 * Note that the only writing these routines do are to the bootmap,
279 	 * and we've made sure to locate the bootmap properly so that they
280 	 * won't be writing over anything important.
281 	 */
282 
283 	bootmap_pfn = bootmap_start_pfn;
284 	max_pfn = 0;
285 	for (i = 0; i < npmem_ranges; i++) {
286 		unsigned long start_pfn;
287 		unsigned long npages;
288 
289 		start_pfn = pmem_ranges[i].start_pfn;
290 		npages = pmem_ranges[i].pages;
291 
292 		bootmap_size = init_bootmem_node(NODE_DATA(i),
293 						bootmap_pfn,
294 						start_pfn,
295 						(start_pfn + npages) );
296 		free_bootmem_node(NODE_DATA(i),
297 				  (start_pfn << PAGE_SHIFT),
298 				  (npages << PAGE_SHIFT) );
299 		bootmap_pfn += (bootmap_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
300 		if ((start_pfn + npages) > max_pfn)
301 			max_pfn = start_pfn + npages;
302 	}
303 
304 	/* IOMMU is always used to access "high mem" on those boxes
305 	 * that can support enough mem that a PCI device couldn't
306 	 * directly DMA to any physical addresses.
307 	 * ISA DMA support will need to revisit this.
308 	 */
309 	max_low_pfn = max_pfn;
310 
311 	if ((bootmap_pfn - bootmap_start_pfn) != bootmap_pages) {
312 		printk(KERN_WARNING "WARNING! bootmap sizing is messed up!\n");
313 		BUG();
314 	}
315 
316 	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
317 
318 #define PDC_CONSOLE_IO_IODC_SIZE 32768
319 
320 	reserve_bootmem_node(NODE_DATA(0), 0UL,
321 			(unsigned long)(PAGE0->mem_free + PDC_CONSOLE_IO_IODC_SIZE));
322 	reserve_bootmem_node(NODE_DATA(0),__pa((unsigned long)&_text),
323 			(unsigned long)(&_end - &_text));
324 	reserve_bootmem_node(NODE_DATA(0), (bootmap_start_pfn << PAGE_SHIFT),
325 			((bootmap_pfn - bootmap_start_pfn) << PAGE_SHIFT));
326 
327 #ifndef CONFIG_DISCONTIGMEM
328 
329 	/* reserve the holes */
330 
331 	for (i = 0; i < npmem_holes; i++) {
332 		reserve_bootmem_node(NODE_DATA(0),
333 				(pmem_holes[i].start_pfn << PAGE_SHIFT),
334 				(pmem_holes[i].pages << PAGE_SHIFT));
335 	}
336 #endif
337 
338 #ifdef CONFIG_BLK_DEV_INITRD
339 	if (initrd_start) {
340 		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
341 		if (__pa(initrd_start) < mem_max) {
342 			unsigned long initrd_reserve;
343 
344 			if (__pa(initrd_end) > mem_max) {
345 				initrd_reserve = mem_max - __pa(initrd_start);
346 			} else {
347 				initrd_reserve = initrd_end - initrd_start;
348 			}
349 			initrd_below_start_ok = 1;
350 			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
351 
352 			reserve_bootmem_node(NODE_DATA(0),__pa(initrd_start), initrd_reserve);
353 		}
354 	}
355 #endif
356 
357 	data_resource.start =  virt_to_phys(&data_start);
358 	data_resource.end = virt_to_phys(&_end)-1;
359 	code_resource.start = virt_to_phys(&_text);
360 	code_resource.end = virt_to_phys(&data_start)-1;
361 
362 	/* We don't know which region the kernel will be in, so try
363 	 * all of them.
364 	 */
365 	for (i = 0; i < sysram_resource_count; i++) {
366 		struct resource *res = &sysram_resources[i];
367 		request_resource(res, &code_resource);
368 		request_resource(res, &data_resource);
369 	}
370 	request_resource(&sysram_resources[0], &pdcdata_resource);
371 }
372 
373 void free_initmem(void)
374 {
375 	unsigned long addr, init_begin, init_end;
376 
377 	printk(KERN_INFO "Freeing unused kernel memory: ");
378 
379 #ifdef CONFIG_DEBUG_KERNEL
380 	/* Attempt to catch anyone trying to execute code here
381 	 * by filling the page with BRK insns.
382 	 *
383 	 * If we disable interrupts for all CPUs, then IPI stops working.
384 	 * Kinda breaks the global cache flushing.
385 	 */
386 	local_irq_disable();
387 
388 	memset(&__init_begin, 0x00,
389 		(unsigned long)&__init_end - (unsigned long)&__init_begin);
390 
391 	flush_data_cache();
392 	asm volatile("sync" : : );
393 	flush_icache_range((unsigned long)&__init_begin, (unsigned long)&__init_end);
394 	asm volatile("sync" : : );
395 
396 	local_irq_enable();
397 #endif
398 
399 	/* align __init_begin and __init_end to page size,
400 	   ignoring linker script where we might have tried to save RAM */
401 	init_begin = PAGE_ALIGN((unsigned long)(&__init_begin));
402 	init_end   = PAGE_ALIGN((unsigned long)(&__init_end));
403 	for (addr = init_begin; addr < init_end; addr += PAGE_SIZE) {
404 		ClearPageReserved(virt_to_page(addr));
405 		init_page_count(virt_to_page(addr));
406 		free_page(addr);
407 		num_physpages++;
408 		totalram_pages++;
409 	}
410 
411 	/* set up a new led state on systems shipped LED State panel */
412 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
413 
414 	printk("%luk freed\n", (init_end - init_begin) >> 10);
415 }
416 
417 
418 #ifdef CONFIG_DEBUG_RODATA
419 void mark_rodata_ro(void)
420 {
421 	extern char __start_rodata, __end_rodata;
422 	/* rodata memory was already mapped with KERNEL_RO access rights by
423            pagetable_init() and map_pages(). No need to do additional stuff here */
424 	printk (KERN_INFO "Write protecting the kernel read-only data: %luk\n",
425 		(unsigned long)(&__end_rodata - &__start_rodata) >> 10);
426 }
427 #endif
428 
429 
430 /*
431  * Just an arbitrary offset to serve as a "hole" between mapping areas
432  * (between top of physical memory and a potential pcxl dma mapping
433  * area, and below the vmalloc mapping area).
434  *
435  * The current 32K value just means that there will be a 32K "hole"
436  * between mapping areas. That means that  any out-of-bounds memory
437  * accesses will hopefully be caught. The vmalloc() routines leaves
438  * a hole of 4kB between each vmalloced area for the same reason.
439  */
440 
441  /* Leave room for gateway page expansion */
442 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
443 #error KERNEL_MAP_START is in gateway reserved region
444 #endif
445 #define MAP_START (KERNEL_MAP_START)
446 
447 #define VM_MAP_OFFSET  (32*1024)
448 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
449 				     & ~(VM_MAP_OFFSET-1)))
450 
451 void *vmalloc_start __read_mostly;
452 EXPORT_SYMBOL(vmalloc_start);
453 
454 #ifdef CONFIG_PA11
455 unsigned long pcxl_dma_start __read_mostly;
456 #endif
457 
458 void __init mem_init(void)
459 {
460 	high_memory = __va((max_pfn << PAGE_SHIFT));
461 
462 #ifndef CONFIG_DISCONTIGMEM
463 	max_mapnr = page_to_pfn(virt_to_page(high_memory - 1)) + 1;
464 	totalram_pages += free_all_bootmem();
465 #else
466 	{
467 		int i;
468 
469 		for (i = 0; i < npmem_ranges; i++)
470 			totalram_pages += free_all_bootmem_node(NODE_DATA(i));
471 	}
472 #endif
473 
474 	printk(KERN_INFO "Memory: %luk available\n", num_physpages << (PAGE_SHIFT-10));
475 
476 #ifdef CONFIG_PA11
477 	if (hppa_dma_ops == &pcxl_dma_ops) {
478 		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
479 		vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start + PCXL_DMA_MAP_SIZE);
480 	} else {
481 		pcxl_dma_start = 0;
482 		vmalloc_start = SET_MAP_OFFSET(MAP_START);
483 	}
484 #else
485 	vmalloc_start = SET_MAP_OFFSET(MAP_START);
486 #endif
487 
488 }
489 
490 unsigned long *empty_zero_page __read_mostly;
491 
492 void show_mem(void)
493 {
494 	int i,free = 0,total = 0,reserved = 0;
495 	int shared = 0, cached = 0;
496 
497 	printk(KERN_INFO "Mem-info:\n");
498 	show_free_areas();
499 	printk(KERN_INFO "Free swap:	 %6ldkB\n",
500 				nr_swap_pages<<(PAGE_SHIFT-10));
501 #ifndef CONFIG_DISCONTIGMEM
502 	i = max_mapnr;
503 	while (i-- > 0) {
504 		total++;
505 		if (PageReserved(mem_map+i))
506 			reserved++;
507 		else if (PageSwapCache(mem_map+i))
508 			cached++;
509 		else if (!page_count(&mem_map[i]))
510 			free++;
511 		else
512 			shared += page_count(&mem_map[i]) - 1;
513 	}
514 #else
515 	for (i = 0; i < npmem_ranges; i++) {
516 		int j;
517 
518 		for (j = node_start_pfn(i); j < node_end_pfn(i); j++) {
519 			struct page *p;
520 			unsigned long flags;
521 
522 			pgdat_resize_lock(NODE_DATA(i), &flags);
523 			p = nid_page_nr(i, j) - node_start_pfn(i);
524 
525 			total++;
526 			if (PageReserved(p))
527 				reserved++;
528 			else if (PageSwapCache(p))
529 				cached++;
530 			else if (!page_count(p))
531 				free++;
532 			else
533 				shared += page_count(p) - 1;
534 			pgdat_resize_unlock(NODE_DATA(i), &flags);
535         	}
536 	}
537 #endif
538 	printk(KERN_INFO "%d pages of RAM\n", total);
539 	printk(KERN_INFO "%d reserved pages\n", reserved);
540 	printk(KERN_INFO "%d pages shared\n", shared);
541 	printk(KERN_INFO "%d pages swap cached\n", cached);
542 
543 
544 #ifdef CONFIG_DISCONTIGMEM
545 	{
546 		struct zonelist *zl;
547 		int i, j, k;
548 
549 		for (i = 0; i < npmem_ranges; i++) {
550 			for (j = 0; j < MAX_NR_ZONES; j++) {
551 				zl = NODE_DATA(i)->node_zonelists + j;
552 
553 				printk("Zone list for zone %d on node %d: ", j, i);
554 				for (k = 0; zl->zones[k] != NULL; k++)
555 					printk("[%d/%s] ", zl->zones[k]->zone_pgdat->node_id, zl->zones[k]->name);
556 				printk("\n");
557 			}
558 		}
559 	}
560 #endif
561 }
562 
563 
564 static void __init map_pages(unsigned long start_vaddr, unsigned long start_paddr, unsigned long size, pgprot_t pgprot)
565 {
566 	pgd_t *pg_dir;
567 	pmd_t *pmd;
568 	pte_t *pg_table;
569 	unsigned long end_paddr;
570 	unsigned long start_pmd;
571 	unsigned long start_pte;
572 	unsigned long tmp1;
573 	unsigned long tmp2;
574 	unsigned long address;
575 	unsigned long ro_start;
576 	unsigned long ro_end;
577 	unsigned long fv_addr;
578 	unsigned long gw_addr;
579 	extern const unsigned long fault_vector_20;
580 	extern void * const linux_gateway_page;
581 
582 	ro_start = __pa((unsigned long)&_text);
583 	ro_end   = __pa((unsigned long)&data_start);
584 	fv_addr  = __pa((unsigned long)&fault_vector_20) & PAGE_MASK;
585 	gw_addr  = __pa((unsigned long)&linux_gateway_page) & PAGE_MASK;
586 
587 	end_paddr = start_paddr + size;
588 
589 	pg_dir = pgd_offset_k(start_vaddr);
590 
591 #if PTRS_PER_PMD == 1
592 	start_pmd = 0;
593 #else
594 	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
595 #endif
596 	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
597 
598 	address = start_paddr;
599 	while (address < end_paddr) {
600 #if PTRS_PER_PMD == 1
601 		pmd = (pmd_t *)__pa(pg_dir);
602 #else
603 		pmd = (pmd_t *)pgd_address(*pg_dir);
604 
605 		/*
606 		 * pmd is physical at this point
607 		 */
608 
609 		if (!pmd) {
610 			pmd = (pmd_t *) alloc_bootmem_low_pages_node(NODE_DATA(0),PAGE_SIZE << PMD_ORDER);
611 			pmd = (pmd_t *) __pa(pmd);
612 		}
613 
614 		pgd_populate(NULL, pg_dir, __va(pmd));
615 #endif
616 		pg_dir++;
617 
618 		/* now change pmd to kernel virtual addresses */
619 
620 		pmd = (pmd_t *)__va(pmd) + start_pmd;
621 		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++,pmd++) {
622 
623 			/*
624 			 * pg_table is physical at this point
625 			 */
626 
627 			pg_table = (pte_t *)pmd_address(*pmd);
628 			if (!pg_table) {
629 				pg_table = (pte_t *)
630 					alloc_bootmem_low_pages_node(NODE_DATA(0),PAGE_SIZE);
631 				pg_table = (pte_t *) __pa(pg_table);
632 			}
633 
634 			pmd_populate_kernel(NULL, pmd, __va(pg_table));
635 
636 			/* now change pg_table to kernel virtual addresses */
637 
638 			pg_table = (pte_t *) __va(pg_table) + start_pte;
639 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++,pg_table++) {
640 				pte_t pte;
641 
642 				/*
643 				 * Map the fault vector writable so we can
644 				 * write the HPMC checksum.
645 				 */
646 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
647 				if (address >= ro_start && address < ro_end
648 							&& address != fv_addr
649 							&& address != gw_addr)
650 				    pte = __mk_pte(address, PAGE_KERNEL_RO);
651 				else
652 #endif
653 				    pte = __mk_pte(address, pgprot);
654 
655 				if (address >= end_paddr)
656 					pte_val(pte) = 0;
657 
658 				set_pte(pg_table, pte);
659 
660 				address += PAGE_SIZE;
661 			}
662 			start_pte = 0;
663 
664 			if (address >= end_paddr)
665 			    break;
666 		}
667 		start_pmd = 0;
668 	}
669 }
670 
671 /*
672  * pagetable_init() sets up the page tables
673  *
674  * Note that gateway_init() places the Linux gateway page at page 0.
675  * Since gateway pages cannot be dereferenced this has the desirable
676  * side effect of trapping those pesky NULL-reference errors in the
677  * kernel.
678  */
679 static void __init pagetable_init(void)
680 {
681 	int range;
682 
683 	/* Map each physical memory range to its kernel vaddr */
684 
685 	for (range = 0; range < npmem_ranges; range++) {
686 		unsigned long start_paddr;
687 		unsigned long end_paddr;
688 		unsigned long size;
689 
690 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
691 		end_paddr = start_paddr + (pmem_ranges[range].pages << PAGE_SHIFT);
692 		size = pmem_ranges[range].pages << PAGE_SHIFT;
693 
694 		map_pages((unsigned long)__va(start_paddr), start_paddr,
695 			size, PAGE_KERNEL);
696 	}
697 
698 #ifdef CONFIG_BLK_DEV_INITRD
699 	if (initrd_end && initrd_end > mem_limit) {
700 		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
701 		map_pages(initrd_start, __pa(initrd_start),
702 			initrd_end - initrd_start, PAGE_KERNEL);
703 	}
704 #endif
705 
706 	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
707 	memset(empty_zero_page, 0, PAGE_SIZE);
708 }
709 
710 static void __init gateway_init(void)
711 {
712 	unsigned long linux_gateway_page_addr;
713 	/* FIXME: This is 'const' in order to trick the compiler
714 	   into not treating it as DP-relative data. */
715 	extern void * const linux_gateway_page;
716 
717 	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
718 
719 	/*
720 	 * Setup Linux Gateway page.
721 	 *
722 	 * The Linux gateway page will reside in kernel space (on virtual
723 	 * page 0), so it doesn't need to be aliased into user space.
724 	 */
725 
726 	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
727 		PAGE_SIZE, PAGE_GATEWAY);
728 }
729 
730 #ifdef CONFIG_HPUX
731 void
732 map_hpux_gateway_page(struct task_struct *tsk, struct mm_struct *mm)
733 {
734 	pgd_t *pg_dir;
735 	pmd_t *pmd;
736 	pte_t *pg_table;
737 	unsigned long start_pmd;
738 	unsigned long start_pte;
739 	unsigned long address;
740 	unsigned long hpux_gw_page_addr;
741 	/* FIXME: This is 'const' in order to trick the compiler
742 	   into not treating it as DP-relative data. */
743 	extern void * const hpux_gateway_page;
744 
745 	hpux_gw_page_addr = HPUX_GATEWAY_ADDR & PAGE_MASK;
746 
747 	/*
748 	 * Setup HP-UX Gateway page.
749 	 *
750 	 * The HP-UX gateway page resides in the user address space,
751 	 * so it needs to be aliased into each process.
752 	 */
753 
754 	pg_dir = pgd_offset(mm,hpux_gw_page_addr);
755 
756 #if PTRS_PER_PMD == 1
757 	start_pmd = 0;
758 #else
759 	start_pmd = ((hpux_gw_page_addr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
760 #endif
761 	start_pte = ((hpux_gw_page_addr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
762 
763 	address = __pa(&hpux_gateway_page);
764 #if PTRS_PER_PMD == 1
765 	pmd = (pmd_t *)__pa(pg_dir);
766 #else
767 	pmd = (pmd_t *) pgd_address(*pg_dir);
768 
769 	/*
770 	 * pmd is physical at this point
771 	 */
772 
773 	if (!pmd) {
774 		pmd = (pmd_t *) get_zeroed_page(GFP_KERNEL);
775 		pmd = (pmd_t *) __pa(pmd);
776 	}
777 
778 	__pgd_val_set(*pg_dir, PxD_FLAG_PRESENT | PxD_FLAG_VALID | (unsigned long) pmd);
779 #endif
780 	/* now change pmd to kernel virtual addresses */
781 
782 	pmd = (pmd_t *)__va(pmd) + start_pmd;
783 
784 	/*
785 	 * pg_table is physical at this point
786 	 */
787 
788 	pg_table = (pte_t *) pmd_address(*pmd);
789 	if (!pg_table)
790 		pg_table = (pte_t *) __pa(get_zeroed_page(GFP_KERNEL));
791 
792 	__pmd_val_set(*pmd, PxD_FLAG_PRESENT | PxD_FLAG_VALID | (unsigned long) pg_table);
793 
794 	/* now change pg_table to kernel virtual addresses */
795 
796 	pg_table = (pte_t *) __va(pg_table) + start_pte;
797 	set_pte(pg_table, __mk_pte(address, PAGE_GATEWAY));
798 }
799 EXPORT_SYMBOL(map_hpux_gateway_page);
800 #endif
801 
802 void __init paging_init(void)
803 {
804 	int i;
805 
806 	setup_bootmem();
807 	pagetable_init();
808 	gateway_init();
809 	flush_cache_all_local(); /* start with known state */
810 	flush_tlb_all_local(NULL);
811 
812 	for (i = 0; i < npmem_ranges; i++) {
813 		unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0 };
814 
815 		/* We have an IOMMU, so all memory can go into a single
816 		   ZONE_DMA zone. */
817 		zones_size[ZONE_DMA] = pmem_ranges[i].pages;
818 
819 #ifdef CONFIG_DISCONTIGMEM
820 		/* Need to initialize the pfnnid_map before we can initialize
821 		   the zone */
822 		{
823 		    int j;
824 		    for (j = (pmem_ranges[i].start_pfn >> PFNNID_SHIFT);
825 			 j <= ((pmem_ranges[i].start_pfn + pmem_ranges[i].pages) >> PFNNID_SHIFT);
826 			 j++) {
827 			pfnnid_map[j] = i;
828 		    }
829 		}
830 #endif
831 
832 		free_area_init_node(i, NODE_DATA(i), zones_size,
833 				pmem_ranges[i].start_pfn, NULL);
834 	}
835 }
836 
837 #ifdef CONFIG_PA20
838 
839 /*
840  * Currently, all PA20 chips have 18 bit protection id's, which is the
841  * limiting factor (space ids are 32 bits).
842  */
843 
844 #define NR_SPACE_IDS 262144
845 
846 #else
847 
848 /*
849  * Currently we have a one-to-one relationship between space id's and
850  * protection id's. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
851  * support 15 bit protection id's, so that is the limiting factor.
852  * PCXT' has 18 bit protection id's, but only 16 bit spaceids, so it's
853  * probably not worth the effort for a special case here.
854  */
855 
856 #define NR_SPACE_IDS 32768
857 
858 #endif  /* !CONFIG_PA20 */
859 
860 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
861 #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
862 
863 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
864 static unsigned long dirty_space_id[SID_ARRAY_SIZE];
865 static unsigned long space_id_index;
866 static unsigned long free_space_ids = NR_SPACE_IDS - 1;
867 static unsigned long dirty_space_ids = 0;
868 
869 static DEFINE_SPINLOCK(sid_lock);
870 
871 unsigned long alloc_sid(void)
872 {
873 	unsigned long index;
874 
875 	spin_lock(&sid_lock);
876 
877 	if (free_space_ids == 0) {
878 		if (dirty_space_ids != 0) {
879 			spin_unlock(&sid_lock);
880 			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
881 			spin_lock(&sid_lock);
882 		}
883 		BUG_ON(free_space_ids == 0);
884 	}
885 
886 	free_space_ids--;
887 
888 	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
889 	space_id[index >> SHIFT_PER_LONG] |= (1L << (index & (BITS_PER_LONG - 1)));
890 	space_id_index = index;
891 
892 	spin_unlock(&sid_lock);
893 
894 	return index << SPACEID_SHIFT;
895 }
896 
897 void free_sid(unsigned long spaceid)
898 {
899 	unsigned long index = spaceid >> SPACEID_SHIFT;
900 	unsigned long *dirty_space_offset;
901 
902 	dirty_space_offset = dirty_space_id + (index >> SHIFT_PER_LONG);
903 	index &= (BITS_PER_LONG - 1);
904 
905 	spin_lock(&sid_lock);
906 
907 	BUG_ON(*dirty_space_offset & (1L << index)); /* attempt to free space id twice */
908 
909 	*dirty_space_offset |= (1L << index);
910 	dirty_space_ids++;
911 
912 	spin_unlock(&sid_lock);
913 }
914 
915 
916 #ifdef CONFIG_SMP
917 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
918 {
919 	int i;
920 
921 	/* NOTE: sid_lock must be held upon entry */
922 
923 	*ndirtyptr = dirty_space_ids;
924 	if (dirty_space_ids != 0) {
925 	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
926 		dirty_array[i] = dirty_space_id[i];
927 		dirty_space_id[i] = 0;
928 	    }
929 	    dirty_space_ids = 0;
930 	}
931 
932 	return;
933 }
934 
935 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
936 {
937 	int i;
938 
939 	/* NOTE: sid_lock must be held upon entry */
940 
941 	if (ndirty != 0) {
942 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
943 			space_id[i] ^= dirty_array[i];
944 		}
945 
946 		free_space_ids += ndirty;
947 		space_id_index = 0;
948 	}
949 }
950 
951 #else /* CONFIG_SMP */
952 
953 static void recycle_sids(void)
954 {
955 	int i;
956 
957 	/* NOTE: sid_lock must be held upon entry */
958 
959 	if (dirty_space_ids != 0) {
960 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
961 			space_id[i] ^= dirty_space_id[i];
962 			dirty_space_id[i] = 0;
963 		}
964 
965 		free_space_ids += dirty_space_ids;
966 		dirty_space_ids = 0;
967 		space_id_index = 0;
968 	}
969 }
970 #endif
971 
972 /*
973  * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
974  * purged, we can safely reuse the space ids that were released but
975  * not flushed from the tlb.
976  */
977 
978 #ifdef CONFIG_SMP
979 
980 static unsigned long recycle_ndirty;
981 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
982 static unsigned int recycle_inuse;
983 
984 void flush_tlb_all(void)
985 {
986 	int do_recycle;
987 
988 	do_recycle = 0;
989 	spin_lock(&sid_lock);
990 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
991 	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
992 	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
993 	    recycle_inuse++;
994 	    do_recycle++;
995 	}
996 	spin_unlock(&sid_lock);
997 	on_each_cpu(flush_tlb_all_local, NULL, 1, 1);
998 	if (do_recycle) {
999 	    spin_lock(&sid_lock);
1000 	    recycle_sids(recycle_ndirty,recycle_dirty_array);
1001 	    recycle_inuse = 0;
1002 	    spin_unlock(&sid_lock);
1003 	}
1004 }
1005 #else
1006 void flush_tlb_all(void)
1007 {
1008 	spin_lock(&sid_lock);
1009 	flush_tlb_all_local(NULL);
1010 	recycle_sids();
1011 	spin_unlock(&sid_lock);
1012 }
1013 #endif
1014 
1015 #ifdef CONFIG_BLK_DEV_INITRD
1016 void free_initrd_mem(unsigned long start, unsigned long end)
1017 {
1018 	if (start >= end)
1019 		return;
1020 	printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
1021 	for (; start < end; start += PAGE_SIZE) {
1022 		ClearPageReserved(virt_to_page(start));
1023 		init_page_count(virt_to_page(start));
1024 		free_page(start);
1025 		num_physpages++;
1026 		totalram_pages++;
1027 	}
1028 }
1029 #endif
1030