xref: /openbmc/linux/arch/parisc/mm/init.c (revision 133f9794)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/parisc/mm/init.c
4  *
5  *  Copyright (C) 1995	Linus Torvalds
6  *  Copyright 1999 SuSE GmbH
7  *    changed by Philipp Rumpf
8  *  Copyright 1999 Philipp Rumpf (prumpf@tux.org)
9  *  Copyright 2004 Randolph Chung (tausq@debian.org)
10  *  Copyright 2006-2007 Helge Deller (deller@gmx.de)
11  *
12  */
13 
14 
15 #include <linux/module.h>
16 #include <linux/mm.h>
17 #include <linux/bootmem.h>
18 #include <linux/memblock.h>
19 #include <linux/gfp.h>
20 #include <linux/delay.h>
21 #include <linux/init.h>
22 #include <linux/pci.h>		/* for hppa_dma_ops and pcxl_dma_ops */
23 #include <linux/initrd.h>
24 #include <linux/swap.h>
25 #include <linux/unistd.h>
26 #include <linux/nodemask.h>	/* for node_online_map */
27 #include <linux/pagemap.h>	/* for release_pages */
28 #include <linux/compat.h>
29 
30 #include <asm/pgalloc.h>
31 #include <asm/pgtable.h>
32 #include <asm/tlb.h>
33 #include <asm/pdc_chassis.h>
34 #include <asm/mmzone.h>
35 #include <asm/sections.h>
36 #include <asm/msgbuf.h>
37 
38 extern int  data_start;
39 extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
40 
41 #if CONFIG_PGTABLE_LEVELS == 3
42 /* NOTE: This layout exactly conforms to the hybrid L2/L3 page table layout
43  * with the first pmd adjacent to the pgd and below it. gcc doesn't actually
44  * guarantee that global objects will be laid out in memory in the same order
45  * as the order of declaration, so put these in different sections and use
46  * the linker script to order them. */
47 pmd_t pmd0[PTRS_PER_PMD] __attribute__ ((__section__ (".data..vm0.pmd"), aligned(PAGE_SIZE)));
48 #endif
49 
50 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((__section__ (".data..vm0.pgd"), aligned(PAGE_SIZE)));
51 pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __attribute__ ((__section__ (".data..vm0.pte"), aligned(PAGE_SIZE)));
52 
53 #ifdef CONFIG_DISCONTIGMEM
54 struct node_map_data node_data[MAX_NUMNODES] __read_mostly;
55 signed char pfnnid_map[PFNNID_MAP_MAX] __read_mostly;
56 #endif
57 
58 static struct resource data_resource = {
59 	.name	= "Kernel data",
60 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
61 };
62 
63 static struct resource code_resource = {
64 	.name	= "Kernel code",
65 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
66 };
67 
68 static struct resource pdcdata_resource = {
69 	.name	= "PDC data (Page Zero)",
70 	.start	= 0,
71 	.end	= 0x9ff,
72 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
73 };
74 
75 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __read_mostly;
76 
77 /* The following array is initialized from the firmware specific
78  * information retrieved in kernel/inventory.c.
79  */
80 
81 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __read_mostly;
82 int npmem_ranges __read_mostly;
83 
84 /*
85  * get_memblock() allocates pages via memblock.
86  * We can't use memblock_find_in_range(0, KERNEL_INITIAL_SIZE) here since it
87  * doesn't allocate from bottom to top which is needed because we only created
88  * the initial mapping up to KERNEL_INITIAL_SIZE in the assembly bootup code.
89  */
90 static void * __init get_memblock(unsigned long size)
91 {
92 	static phys_addr_t search_addr __initdata;
93 	phys_addr_t phys;
94 
95 	if (!search_addr)
96 		search_addr = PAGE_ALIGN(__pa((unsigned long) &_end));
97 	search_addr = ALIGN(search_addr, size);
98 	while (!memblock_is_region_memory(search_addr, size) ||
99 		memblock_is_region_reserved(search_addr, size)) {
100 		search_addr += size;
101 	}
102 	phys = search_addr;
103 
104 	if (phys)
105 		memblock_reserve(phys, size);
106 	else
107 		panic("get_memblock() failed.\n");
108 
109 	memset(__va(phys), 0, size);
110 
111 	return __va(phys);
112 }
113 
114 #ifdef CONFIG_64BIT
115 #define MAX_MEM         (~0UL)
116 #else /* !CONFIG_64BIT */
117 #define MAX_MEM         (3584U*1024U*1024U)
118 #endif /* !CONFIG_64BIT */
119 
120 static unsigned long mem_limit __read_mostly = MAX_MEM;
121 
122 static void __init mem_limit_func(void)
123 {
124 	char *cp, *end;
125 	unsigned long limit;
126 
127 	/* We need this before __setup() functions are called */
128 
129 	limit = MAX_MEM;
130 	for (cp = boot_command_line; *cp; ) {
131 		if (memcmp(cp, "mem=", 4) == 0) {
132 			cp += 4;
133 			limit = memparse(cp, &end);
134 			if (end != cp)
135 				break;
136 			cp = end;
137 		} else {
138 			while (*cp != ' ' && *cp)
139 				++cp;
140 			while (*cp == ' ')
141 				++cp;
142 		}
143 	}
144 
145 	if (limit < mem_limit)
146 		mem_limit = limit;
147 }
148 
149 #define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
150 
151 static void __init setup_bootmem(void)
152 {
153 	unsigned long mem_max;
154 #ifndef CONFIG_DISCONTIGMEM
155 	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
156 	int npmem_holes;
157 #endif
158 	int i, sysram_resource_count;
159 
160 	disable_sr_hashing(); /* Turn off space register hashing */
161 
162 	/*
163 	 * Sort the ranges. Since the number of ranges is typically
164 	 * small, and performance is not an issue here, just do
165 	 * a simple insertion sort.
166 	 */
167 
168 	for (i = 1; i < npmem_ranges; i++) {
169 		int j;
170 
171 		for (j = i; j > 0; j--) {
172 			unsigned long tmp;
173 
174 			if (pmem_ranges[j-1].start_pfn <
175 			    pmem_ranges[j].start_pfn) {
176 
177 				break;
178 			}
179 			tmp = pmem_ranges[j-1].start_pfn;
180 			pmem_ranges[j-1].start_pfn = pmem_ranges[j].start_pfn;
181 			pmem_ranges[j].start_pfn = tmp;
182 			tmp = pmem_ranges[j-1].pages;
183 			pmem_ranges[j-1].pages = pmem_ranges[j].pages;
184 			pmem_ranges[j].pages = tmp;
185 		}
186 	}
187 
188 #ifndef CONFIG_DISCONTIGMEM
189 	/*
190 	 * Throw out ranges that are too far apart (controlled by
191 	 * MAX_GAP).
192 	 */
193 
194 	for (i = 1; i < npmem_ranges; i++) {
195 		if (pmem_ranges[i].start_pfn -
196 			(pmem_ranges[i-1].start_pfn +
197 			 pmem_ranges[i-1].pages) > MAX_GAP) {
198 			npmem_ranges = i;
199 			printk("Large gap in memory detected (%ld pages). "
200 			       "Consider turning on CONFIG_DISCONTIGMEM\n",
201 			       pmem_ranges[i].start_pfn -
202 			       (pmem_ranges[i-1].start_pfn +
203 			        pmem_ranges[i-1].pages));
204 			break;
205 		}
206 	}
207 #endif
208 
209 	/* Print the memory ranges */
210 	pr_info("Memory Ranges:\n");
211 
212 	for (i = 0; i < npmem_ranges; i++) {
213 		struct resource *res = &sysram_resources[i];
214 		unsigned long start;
215 		unsigned long size;
216 
217 		size = (pmem_ranges[i].pages << PAGE_SHIFT);
218 		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
219 		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
220 			i, start, start + (size - 1), size >> 20);
221 
222 		/* request memory resource */
223 		res->name = "System RAM";
224 		res->start = start;
225 		res->end = start + size - 1;
226 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
227 		request_resource(&iomem_resource, res);
228 	}
229 
230 	sysram_resource_count = npmem_ranges;
231 
232 	/*
233 	 * For 32 bit kernels we limit the amount of memory we can
234 	 * support, in order to preserve enough kernel address space
235 	 * for other purposes. For 64 bit kernels we don't normally
236 	 * limit the memory, but this mechanism can be used to
237 	 * artificially limit the amount of memory (and it is written
238 	 * to work with multiple memory ranges).
239 	 */
240 
241 	mem_limit_func();       /* check for "mem=" argument */
242 
243 	mem_max = 0;
244 	for (i = 0; i < npmem_ranges; i++) {
245 		unsigned long rsize;
246 
247 		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
248 		if ((mem_max + rsize) > mem_limit) {
249 			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
250 			if (mem_max == mem_limit)
251 				npmem_ranges = i;
252 			else {
253 				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
254 						       - (mem_max >> PAGE_SHIFT);
255 				npmem_ranges = i + 1;
256 				mem_max = mem_limit;
257 			}
258 			break;
259 		}
260 		mem_max += rsize;
261 	}
262 
263 	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
264 
265 #ifndef CONFIG_DISCONTIGMEM
266 	/* Merge the ranges, keeping track of the holes */
267 
268 	{
269 		unsigned long end_pfn;
270 		unsigned long hole_pages;
271 
272 		npmem_holes = 0;
273 		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
274 		for (i = 1; i < npmem_ranges; i++) {
275 
276 			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
277 			if (hole_pages) {
278 				pmem_holes[npmem_holes].start_pfn = end_pfn;
279 				pmem_holes[npmem_holes++].pages = hole_pages;
280 				end_pfn += hole_pages;
281 			}
282 			end_pfn += pmem_ranges[i].pages;
283 		}
284 
285 		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
286 		npmem_ranges = 1;
287 	}
288 #endif
289 
290 #ifdef CONFIG_DISCONTIGMEM
291 	for (i = 0; i < MAX_PHYSMEM_RANGES; i++) {
292 		memset(NODE_DATA(i), 0, sizeof(pg_data_t));
293 	}
294 	memset(pfnnid_map, 0xff, sizeof(pfnnid_map));
295 
296 	for (i = 0; i < npmem_ranges; i++) {
297 		node_set_state(i, N_NORMAL_MEMORY);
298 		node_set_online(i);
299 	}
300 #endif
301 
302 	/*
303 	 * Initialize and free the full range of memory in each range.
304 	 */
305 
306 	max_pfn = 0;
307 	for (i = 0; i < npmem_ranges; i++) {
308 		unsigned long start_pfn;
309 		unsigned long npages;
310 		unsigned long start;
311 		unsigned long size;
312 
313 		start_pfn = pmem_ranges[i].start_pfn;
314 		npages = pmem_ranges[i].pages;
315 
316 		start = start_pfn << PAGE_SHIFT;
317 		size = npages << PAGE_SHIFT;
318 
319 		/* add system RAM memblock */
320 		memblock_add(start, size);
321 
322 		if ((start_pfn + npages) > max_pfn)
323 			max_pfn = start_pfn + npages;
324 	}
325 
326 	/* IOMMU is always used to access "high mem" on those boxes
327 	 * that can support enough mem that a PCI device couldn't
328 	 * directly DMA to any physical addresses.
329 	 * ISA DMA support will need to revisit this.
330 	 */
331 	max_low_pfn = max_pfn;
332 
333 	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
334 
335 #define PDC_CONSOLE_IO_IODC_SIZE 32768
336 
337 	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
338 				PDC_CONSOLE_IO_IODC_SIZE));
339 	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
340 			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
341 
342 #ifndef CONFIG_DISCONTIGMEM
343 
344 	/* reserve the holes */
345 
346 	for (i = 0; i < npmem_holes; i++) {
347 		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
348 				(pmem_holes[i].pages << PAGE_SHIFT));
349 	}
350 #endif
351 
352 #ifdef CONFIG_BLK_DEV_INITRD
353 	if (initrd_start) {
354 		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
355 		if (__pa(initrd_start) < mem_max) {
356 			unsigned long initrd_reserve;
357 
358 			if (__pa(initrd_end) > mem_max) {
359 				initrd_reserve = mem_max - __pa(initrd_start);
360 			} else {
361 				initrd_reserve = initrd_end - initrd_start;
362 			}
363 			initrd_below_start_ok = 1;
364 			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
365 
366 			memblock_reserve(__pa(initrd_start), initrd_reserve);
367 		}
368 	}
369 #endif
370 
371 	data_resource.start =  virt_to_phys(&data_start);
372 	data_resource.end = virt_to_phys(_end) - 1;
373 	code_resource.start = virt_to_phys(_text);
374 	code_resource.end = virt_to_phys(&data_start)-1;
375 
376 	/* We don't know which region the kernel will be in, so try
377 	 * all of them.
378 	 */
379 	for (i = 0; i < sysram_resource_count; i++) {
380 		struct resource *res = &sysram_resources[i];
381 		request_resource(res, &code_resource);
382 		request_resource(res, &data_resource);
383 	}
384 	request_resource(&sysram_resources[0], &pdcdata_resource);
385 
386 	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
387 	pdc_pdt_init();
388 }
389 
390 static int __init parisc_text_address(unsigned long vaddr)
391 {
392 	static unsigned long head_ptr __initdata;
393 
394 	if (!head_ptr)
395 		head_ptr = PAGE_MASK & (unsigned long)
396 			dereference_function_descriptor(&parisc_kernel_start);
397 
398 	return core_kernel_text(vaddr) || vaddr == head_ptr;
399 }
400 
401 static void __init map_pages(unsigned long start_vaddr,
402 			     unsigned long start_paddr, unsigned long size,
403 			     pgprot_t pgprot, int force)
404 {
405 	pgd_t *pg_dir;
406 	pmd_t *pmd;
407 	pte_t *pg_table;
408 	unsigned long end_paddr;
409 	unsigned long start_pmd;
410 	unsigned long start_pte;
411 	unsigned long tmp1;
412 	unsigned long tmp2;
413 	unsigned long address;
414 	unsigned long vaddr;
415 	unsigned long ro_start;
416 	unsigned long ro_end;
417 	unsigned long kernel_end;
418 
419 	ro_start = __pa((unsigned long)_text);
420 	ro_end   = __pa((unsigned long)&data_start);
421 	kernel_end  = __pa((unsigned long)&_end);
422 
423 	end_paddr = start_paddr + size;
424 
425 	pg_dir = pgd_offset_k(start_vaddr);
426 
427 #if PTRS_PER_PMD == 1
428 	start_pmd = 0;
429 #else
430 	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
431 #endif
432 	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
433 
434 	address = start_paddr;
435 	vaddr = start_vaddr;
436 	while (address < end_paddr) {
437 #if PTRS_PER_PMD == 1
438 		pmd = (pmd_t *)__pa(pg_dir);
439 #else
440 		pmd = (pmd_t *)pgd_address(*pg_dir);
441 
442 		/*
443 		 * pmd is physical at this point
444 		 */
445 
446 		if (!pmd) {
447 			pmd = (pmd_t *) get_memblock(PAGE_SIZE << PMD_ORDER);
448 			pmd = (pmd_t *) __pa(pmd);
449 		}
450 
451 		pgd_populate(NULL, pg_dir, __va(pmd));
452 #endif
453 		pg_dir++;
454 
455 		/* now change pmd to kernel virtual addresses */
456 
457 		pmd = (pmd_t *)__va(pmd) + start_pmd;
458 		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
459 
460 			/*
461 			 * pg_table is physical at this point
462 			 */
463 
464 			pg_table = (pte_t *)pmd_address(*pmd);
465 			if (!pg_table) {
466 				pg_table = (pte_t *) get_memblock(PAGE_SIZE);
467 				pg_table = (pte_t *) __pa(pg_table);
468 			}
469 
470 			pmd_populate_kernel(NULL, pmd, __va(pg_table));
471 
472 			/* now change pg_table to kernel virtual addresses */
473 
474 			pg_table = (pte_t *) __va(pg_table) + start_pte;
475 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
476 				pte_t pte;
477 
478 				if (force)
479 					pte =  __mk_pte(address, pgprot);
480 				else if (parisc_text_address(vaddr)) {
481 					pte = __mk_pte(address, PAGE_KERNEL_EXEC);
482 					if (address >= ro_start && address < kernel_end)
483 						pte = pte_mkhuge(pte);
484 				}
485 				else
486 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
487 				if (address >= ro_start && address < ro_end) {
488 					pte = __mk_pte(address, PAGE_KERNEL_EXEC);
489 					pte = pte_mkhuge(pte);
490 				} else
491 #endif
492 				{
493 					pte = __mk_pte(address, pgprot);
494 					if (address >= ro_start && address < kernel_end)
495 						pte = pte_mkhuge(pte);
496 				}
497 
498 				if (address >= end_paddr) {
499 					if (force)
500 						break;
501 					else
502 						pte_val(pte) = 0;
503 				}
504 
505 				set_pte(pg_table, pte);
506 
507 				address += PAGE_SIZE;
508 				vaddr += PAGE_SIZE;
509 			}
510 			start_pte = 0;
511 
512 			if (address >= end_paddr)
513 			    break;
514 		}
515 		start_pmd = 0;
516 	}
517 }
518 
519 void free_initmem(void)
520 {
521 	unsigned long init_begin = (unsigned long)__init_begin;
522 	unsigned long init_end = (unsigned long)__init_end;
523 
524 	/* The init text pages are marked R-X.  We have to
525 	 * flush the icache and mark them RW-
526 	 *
527 	 * This is tricky, because map_pages is in the init section.
528 	 * Do a dummy remap of the data section first (the data
529 	 * section is already PAGE_KERNEL) to pull in the TLB entries
530 	 * for map_kernel */
531 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
532 		  PAGE_KERNEL_RWX, 1);
533 	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
534 	 * map_pages */
535 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
536 		  PAGE_KERNEL, 1);
537 
538 	/* force the kernel to see the new TLB entries */
539 	__flush_tlb_range(0, init_begin, init_end);
540 
541 	/* finally dump all the instructions which were cached, since the
542 	 * pages are no-longer executable */
543 	flush_icache_range(init_begin, init_end);
544 
545 	free_initmem_default(POISON_FREE_INITMEM);
546 
547 	/* set up a new led state on systems shipped LED State panel */
548 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
549 }
550 
551 
552 #ifdef CONFIG_STRICT_KERNEL_RWX
553 void mark_rodata_ro(void)
554 {
555 	/* rodata memory was already mapped with KERNEL_RO access rights by
556            pagetable_init() and map_pages(). No need to do additional stuff here */
557 	printk (KERN_INFO "Write protecting the kernel read-only data: %luk\n",
558 		(unsigned long)(__end_rodata - __start_rodata) >> 10);
559 }
560 #endif
561 
562 
563 /*
564  * Just an arbitrary offset to serve as a "hole" between mapping areas
565  * (between top of physical memory and a potential pcxl dma mapping
566  * area, and below the vmalloc mapping area).
567  *
568  * The current 32K value just means that there will be a 32K "hole"
569  * between mapping areas. That means that  any out-of-bounds memory
570  * accesses will hopefully be caught. The vmalloc() routines leaves
571  * a hole of 4kB between each vmalloced area for the same reason.
572  */
573 
574  /* Leave room for gateway page expansion */
575 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
576 #error KERNEL_MAP_START is in gateway reserved region
577 #endif
578 #define MAP_START (KERNEL_MAP_START)
579 
580 #define VM_MAP_OFFSET  (32*1024)
581 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
582 				     & ~(VM_MAP_OFFSET-1)))
583 
584 void *parisc_vmalloc_start __read_mostly;
585 EXPORT_SYMBOL(parisc_vmalloc_start);
586 
587 #ifdef CONFIG_PA11
588 unsigned long pcxl_dma_start __read_mostly;
589 #endif
590 
591 void __init mem_init(void)
592 {
593 	/* Do sanity checks on IPC (compat) structures */
594 	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
595 #ifndef CONFIG_64BIT
596 	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
597 	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
598 	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
599 #endif
600 #ifdef CONFIG_COMPAT
601 	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
602 	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
603 	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
604 	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
605 #endif
606 
607 	/* Do sanity checks on page table constants */
608 	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
609 	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
610 	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
611 	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
612 			> BITS_PER_LONG);
613 
614 	high_memory = __va((max_pfn << PAGE_SHIFT));
615 	set_max_mapnr(page_to_pfn(virt_to_page(high_memory - 1)) + 1);
616 	free_all_bootmem();
617 
618 #ifdef CONFIG_PA11
619 	if (hppa_dma_ops == &pcxl_dma_ops) {
620 		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
621 		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
622 						+ PCXL_DMA_MAP_SIZE);
623 	} else {
624 		pcxl_dma_start = 0;
625 		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
626 	}
627 #else
628 	parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
629 #endif
630 
631 	mem_init_print_info(NULL);
632 #ifdef CONFIG_DEBUG_KERNEL /* double-sanity-check paranoia */
633 	printk("virtual kernel memory layout:\n"
634 	       "    vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
635 	       "    memory  : 0x%px - 0x%px   (%4ld MB)\n"
636 	       "      .init : 0x%px - 0x%px   (%4ld kB)\n"
637 	       "      .data : 0x%px - 0x%px   (%4ld kB)\n"
638 	       "      .text : 0x%px - 0x%px   (%4ld kB)\n",
639 
640 	       (void*)VMALLOC_START, (void*)VMALLOC_END,
641 	       (VMALLOC_END - VMALLOC_START) >> 20,
642 
643 	       __va(0), high_memory,
644 	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
645 
646 	       __init_begin, __init_end,
647 	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
648 
649 	       _etext, _edata,
650 	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
651 
652 	       _text, _etext,
653 	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
654 #endif
655 }
656 
657 unsigned long *empty_zero_page __read_mostly;
658 EXPORT_SYMBOL(empty_zero_page);
659 
660 /*
661  * pagetable_init() sets up the page tables
662  *
663  * Note that gateway_init() places the Linux gateway page at page 0.
664  * Since gateway pages cannot be dereferenced this has the desirable
665  * side effect of trapping those pesky NULL-reference errors in the
666  * kernel.
667  */
668 static void __init pagetable_init(void)
669 {
670 	int range;
671 
672 	/* Map each physical memory range to its kernel vaddr */
673 
674 	for (range = 0; range < npmem_ranges; range++) {
675 		unsigned long start_paddr;
676 		unsigned long end_paddr;
677 		unsigned long size;
678 
679 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
680 		size = pmem_ranges[range].pages << PAGE_SHIFT;
681 		end_paddr = start_paddr + size;
682 
683 		map_pages((unsigned long)__va(start_paddr), start_paddr,
684 			  size, PAGE_KERNEL, 0);
685 	}
686 
687 #ifdef CONFIG_BLK_DEV_INITRD
688 	if (initrd_end && initrd_end > mem_limit) {
689 		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
690 		map_pages(initrd_start, __pa(initrd_start),
691 			  initrd_end - initrd_start, PAGE_KERNEL, 0);
692 	}
693 #endif
694 
695 	empty_zero_page = get_memblock(PAGE_SIZE);
696 }
697 
698 static void __init gateway_init(void)
699 {
700 	unsigned long linux_gateway_page_addr;
701 	/* FIXME: This is 'const' in order to trick the compiler
702 	   into not treating it as DP-relative data. */
703 	extern void * const linux_gateway_page;
704 
705 	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
706 
707 	/*
708 	 * Setup Linux Gateway page.
709 	 *
710 	 * The Linux gateway page will reside in kernel space (on virtual
711 	 * page 0), so it doesn't need to be aliased into user space.
712 	 */
713 
714 	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
715 		  PAGE_SIZE, PAGE_GATEWAY, 1);
716 }
717 
718 void __init paging_init(void)
719 {
720 	int i;
721 
722 	setup_bootmem();
723 	pagetable_init();
724 	gateway_init();
725 	flush_cache_all_local(); /* start with known state */
726 	flush_tlb_all_local(NULL);
727 
728 	for (i = 0; i < npmem_ranges; i++) {
729 		unsigned long zones_size[MAX_NR_ZONES] = { 0, };
730 
731 		zones_size[ZONE_NORMAL] = pmem_ranges[i].pages;
732 
733 #ifdef CONFIG_DISCONTIGMEM
734 		/* Need to initialize the pfnnid_map before we can initialize
735 		   the zone */
736 		{
737 		    int j;
738 		    for (j = (pmem_ranges[i].start_pfn >> PFNNID_SHIFT);
739 			 j <= ((pmem_ranges[i].start_pfn + pmem_ranges[i].pages) >> PFNNID_SHIFT);
740 			 j++) {
741 			pfnnid_map[j] = i;
742 		    }
743 		}
744 #endif
745 
746 		free_area_init_node(i, zones_size,
747 				pmem_ranges[i].start_pfn, NULL);
748 	}
749 }
750 
751 #ifdef CONFIG_PA20
752 
753 /*
754  * Currently, all PA20 chips have 18 bit protection IDs, which is the
755  * limiting factor (space ids are 32 bits).
756  */
757 
758 #define NR_SPACE_IDS 262144
759 
760 #else
761 
762 /*
763  * Currently we have a one-to-one relationship between space IDs and
764  * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
765  * support 15 bit protection IDs, so that is the limiting factor.
766  * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
767  * probably not worth the effort for a special case here.
768  */
769 
770 #define NR_SPACE_IDS 32768
771 
772 #endif  /* !CONFIG_PA20 */
773 
774 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
775 #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
776 
777 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
778 static unsigned long dirty_space_id[SID_ARRAY_SIZE];
779 static unsigned long space_id_index;
780 static unsigned long free_space_ids = NR_SPACE_IDS - 1;
781 static unsigned long dirty_space_ids = 0;
782 
783 static DEFINE_SPINLOCK(sid_lock);
784 
785 unsigned long alloc_sid(void)
786 {
787 	unsigned long index;
788 
789 	spin_lock(&sid_lock);
790 
791 	if (free_space_ids == 0) {
792 		if (dirty_space_ids != 0) {
793 			spin_unlock(&sid_lock);
794 			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
795 			spin_lock(&sid_lock);
796 		}
797 		BUG_ON(free_space_ids == 0);
798 	}
799 
800 	free_space_ids--;
801 
802 	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
803 	space_id[index >> SHIFT_PER_LONG] |= (1L << (index & (BITS_PER_LONG - 1)));
804 	space_id_index = index;
805 
806 	spin_unlock(&sid_lock);
807 
808 	return index << SPACEID_SHIFT;
809 }
810 
811 void free_sid(unsigned long spaceid)
812 {
813 	unsigned long index = spaceid >> SPACEID_SHIFT;
814 	unsigned long *dirty_space_offset;
815 
816 	dirty_space_offset = dirty_space_id + (index >> SHIFT_PER_LONG);
817 	index &= (BITS_PER_LONG - 1);
818 
819 	spin_lock(&sid_lock);
820 
821 	BUG_ON(*dirty_space_offset & (1L << index)); /* attempt to free space id twice */
822 
823 	*dirty_space_offset |= (1L << index);
824 	dirty_space_ids++;
825 
826 	spin_unlock(&sid_lock);
827 }
828 
829 
830 #ifdef CONFIG_SMP
831 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
832 {
833 	int i;
834 
835 	/* NOTE: sid_lock must be held upon entry */
836 
837 	*ndirtyptr = dirty_space_ids;
838 	if (dirty_space_ids != 0) {
839 	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
840 		dirty_array[i] = dirty_space_id[i];
841 		dirty_space_id[i] = 0;
842 	    }
843 	    dirty_space_ids = 0;
844 	}
845 
846 	return;
847 }
848 
849 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
850 {
851 	int i;
852 
853 	/* NOTE: sid_lock must be held upon entry */
854 
855 	if (ndirty != 0) {
856 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
857 			space_id[i] ^= dirty_array[i];
858 		}
859 
860 		free_space_ids += ndirty;
861 		space_id_index = 0;
862 	}
863 }
864 
865 #else /* CONFIG_SMP */
866 
867 static void recycle_sids(void)
868 {
869 	int i;
870 
871 	/* NOTE: sid_lock must be held upon entry */
872 
873 	if (dirty_space_ids != 0) {
874 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
875 			space_id[i] ^= dirty_space_id[i];
876 			dirty_space_id[i] = 0;
877 		}
878 
879 		free_space_ids += dirty_space_ids;
880 		dirty_space_ids = 0;
881 		space_id_index = 0;
882 	}
883 }
884 #endif
885 
886 /*
887  * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
888  * purged, we can safely reuse the space ids that were released but
889  * not flushed from the tlb.
890  */
891 
892 #ifdef CONFIG_SMP
893 
894 static unsigned long recycle_ndirty;
895 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
896 static unsigned int recycle_inuse;
897 
898 void flush_tlb_all(void)
899 {
900 	int do_recycle;
901 
902 	__inc_irq_stat(irq_tlb_count);
903 	do_recycle = 0;
904 	spin_lock(&sid_lock);
905 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
906 	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
907 	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
908 	    recycle_inuse++;
909 	    do_recycle++;
910 	}
911 	spin_unlock(&sid_lock);
912 	on_each_cpu(flush_tlb_all_local, NULL, 1);
913 	if (do_recycle) {
914 	    spin_lock(&sid_lock);
915 	    recycle_sids(recycle_ndirty,recycle_dirty_array);
916 	    recycle_inuse = 0;
917 	    spin_unlock(&sid_lock);
918 	}
919 }
920 #else
921 void flush_tlb_all(void)
922 {
923 	__inc_irq_stat(irq_tlb_count);
924 	spin_lock(&sid_lock);
925 	flush_tlb_all_local(NULL);
926 	recycle_sids();
927 	spin_unlock(&sid_lock);
928 }
929 #endif
930 
931 #ifdef CONFIG_BLK_DEV_INITRD
932 void free_initrd_mem(unsigned long start, unsigned long end)
933 {
934 	free_reserved_area((void *)start, (void *)end, -1, "initrd");
935 }
936 #endif
937