xref: /linux/arch/parisc/mm/init.c (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
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/memblock.h>
18 #include <linux/gfp.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
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 */
26 #include <linux/compat.h>
27 
28 #include <asm/pgalloc.h>
29 #include <asm/tlb.h>
30 #include <asm/pdc_chassis.h>
31 #include <asm/mmzone.h>
32 #include <asm/sections.h>
33 #include <asm/msgbuf.h>
34 #include <asm/sparsemem.h>
35 #include <asm/asm-offsets.h>
36 #include <asm/shmbuf.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 pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
43 #endif
44 
45 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
46 pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
47 
48 static struct resource data_resource = {
49 	.name	= "Kernel data",
50 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
51 };
52 
53 static struct resource code_resource = {
54 	.name	= "Kernel code",
55 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
56 };
57 
58 static struct resource pdcdata_resource = {
59 	.name	= "PDC data (Page Zero)",
60 	.start	= 0,
61 	.end	= 0x9ff,
62 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
63 };
64 
65 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
66 
67 /* The following array is initialized from the firmware specific
68  * information retrieved in kernel/inventory.c.
69  */
70 
71 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
72 int npmem_ranges __initdata;
73 
74 #ifdef CONFIG_64BIT
75 #define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
76 #else /* !CONFIG_64BIT */
77 #define MAX_MEM         (3584U*1024U*1024U)
78 #endif /* !CONFIG_64BIT */
79 
80 static unsigned long mem_limit __read_mostly = MAX_MEM;
81 
82 static void __init mem_limit_func(void)
83 {
84 	char *cp, *end;
85 	unsigned long limit;
86 
87 	/* We need this before __setup() functions are called */
88 
89 	limit = MAX_MEM;
90 	for (cp = boot_command_line; *cp; ) {
91 		if (memcmp(cp, "mem=", 4) == 0) {
92 			cp += 4;
93 			limit = memparse(cp, &end);
94 			if (end != cp)
95 				break;
96 			cp = end;
97 		} else {
98 			while (*cp != ' ' && *cp)
99 				++cp;
100 			while (*cp == ' ')
101 				++cp;
102 		}
103 	}
104 
105 	if (limit < mem_limit)
106 		mem_limit = limit;
107 }
108 
109 #define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
110 
111 static void __init setup_bootmem(void)
112 {
113 	unsigned long mem_max;
114 #ifndef CONFIG_SPARSEMEM
115 	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
116 	int npmem_holes;
117 #endif
118 	int i, sysram_resource_count;
119 
120 	disable_sr_hashing(); /* Turn off space register hashing */
121 
122 	/*
123 	 * Sort the ranges. Since the number of ranges is typically
124 	 * small, and performance is not an issue here, just do
125 	 * a simple insertion sort.
126 	 */
127 
128 	for (i = 1; i < npmem_ranges; i++) {
129 		int j;
130 
131 		for (j = i; j > 0; j--) {
132 			if (pmem_ranges[j-1].start_pfn <
133 			    pmem_ranges[j].start_pfn) {
134 
135 				break;
136 			}
137 			swap(pmem_ranges[j-1], pmem_ranges[j]);
138 		}
139 	}
140 
141 #ifndef CONFIG_SPARSEMEM
142 	/*
143 	 * Throw out ranges that are too far apart (controlled by
144 	 * MAX_GAP).
145 	 */
146 
147 	for (i = 1; i < npmem_ranges; i++) {
148 		if (pmem_ranges[i].start_pfn -
149 			(pmem_ranges[i-1].start_pfn +
150 			 pmem_ranges[i-1].pages) > MAX_GAP) {
151 			npmem_ranges = i;
152 			printk("Large gap in memory detected (%ld pages). "
153 			       "Consider turning on CONFIG_SPARSEMEM\n",
154 			       pmem_ranges[i].start_pfn -
155 			       (pmem_ranges[i-1].start_pfn +
156 			        pmem_ranges[i-1].pages));
157 			break;
158 		}
159 	}
160 #endif
161 
162 	/* Print the memory ranges */
163 	pr_info("Memory Ranges:\n");
164 
165 	for (i = 0; i < npmem_ranges; i++) {
166 		struct resource *res = &sysram_resources[i];
167 		unsigned long start;
168 		unsigned long size;
169 
170 		size = (pmem_ranges[i].pages << PAGE_SHIFT);
171 		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
172 		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
173 			i, start, start + (size - 1), size >> 20);
174 
175 		/* request memory resource */
176 		res->name = "System RAM";
177 		res->start = start;
178 		res->end = start + size - 1;
179 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
180 		request_resource(&iomem_resource, res);
181 	}
182 
183 	sysram_resource_count = npmem_ranges;
184 
185 	/*
186 	 * For 32 bit kernels we limit the amount of memory we can
187 	 * support, in order to preserve enough kernel address space
188 	 * for other purposes. For 64 bit kernels we don't normally
189 	 * limit the memory, but this mechanism can be used to
190 	 * artificially limit the amount of memory (and it is written
191 	 * to work with multiple memory ranges).
192 	 */
193 
194 	mem_limit_func();       /* check for "mem=" argument */
195 
196 	mem_max = 0;
197 	for (i = 0; i < npmem_ranges; i++) {
198 		unsigned long rsize;
199 
200 		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
201 		if ((mem_max + rsize) > mem_limit) {
202 			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
203 			if (mem_max == mem_limit)
204 				npmem_ranges = i;
205 			else {
206 				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
207 						       - (mem_max >> PAGE_SHIFT);
208 				npmem_ranges = i + 1;
209 				mem_max = mem_limit;
210 			}
211 			break;
212 		}
213 		mem_max += rsize;
214 	}
215 
216 	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
217 
218 #ifndef CONFIG_SPARSEMEM
219 	/* Merge the ranges, keeping track of the holes */
220 	{
221 		unsigned long end_pfn;
222 		unsigned long hole_pages;
223 
224 		npmem_holes = 0;
225 		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
226 		for (i = 1; i < npmem_ranges; i++) {
227 
228 			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
229 			if (hole_pages) {
230 				pmem_holes[npmem_holes].start_pfn = end_pfn;
231 				pmem_holes[npmem_holes++].pages = hole_pages;
232 				end_pfn += hole_pages;
233 			}
234 			end_pfn += pmem_ranges[i].pages;
235 		}
236 
237 		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
238 		npmem_ranges = 1;
239 	}
240 #endif
241 
242 	/*
243 	 * Initialize and free the full range of memory in each range.
244 	 */
245 
246 	max_pfn = 0;
247 	for (i = 0; i < npmem_ranges; i++) {
248 		unsigned long start_pfn;
249 		unsigned long npages;
250 		unsigned long start;
251 		unsigned long size;
252 
253 		start_pfn = pmem_ranges[i].start_pfn;
254 		npages = pmem_ranges[i].pages;
255 
256 		start = start_pfn << PAGE_SHIFT;
257 		size = npages << PAGE_SHIFT;
258 
259 		/* add system RAM memblock */
260 		memblock_add(start, size);
261 
262 		if ((start_pfn + npages) > max_pfn)
263 			max_pfn = start_pfn + npages;
264 	}
265 
266 	/*
267 	 * We can't use memblock top-down allocations because we only
268 	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
269 	 * the assembly bootup code.
270 	 */
271 	memblock_set_bottom_up(true);
272 
273 	/* IOMMU is always used to access "high mem" on those boxes
274 	 * that can support enough mem that a PCI device couldn't
275 	 * directly DMA to any physical addresses.
276 	 * ISA DMA support will need to revisit this.
277 	 */
278 	max_low_pfn = max_pfn;
279 
280 	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
281 
282 #define PDC_CONSOLE_IO_IODC_SIZE 32768
283 
284 	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
285 				PDC_CONSOLE_IO_IODC_SIZE));
286 	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
287 			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
288 
289 #ifndef CONFIG_SPARSEMEM
290 
291 	/* reserve the holes */
292 
293 	for (i = 0; i < npmem_holes; i++) {
294 		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
295 				(pmem_holes[i].pages << PAGE_SHIFT));
296 	}
297 #endif
298 
299 #ifdef CONFIG_BLK_DEV_INITRD
300 	if (initrd_start) {
301 		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
302 		if (__pa(initrd_start) < mem_max) {
303 			unsigned long initrd_reserve;
304 
305 			if (__pa(initrd_end) > mem_max) {
306 				initrd_reserve = mem_max - __pa(initrd_start);
307 			} else {
308 				initrd_reserve = initrd_end - initrd_start;
309 			}
310 			initrd_below_start_ok = 1;
311 			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
312 
313 			memblock_reserve(__pa(initrd_start), initrd_reserve);
314 		}
315 	}
316 #endif
317 
318 	data_resource.start =  virt_to_phys(&data_start);
319 	data_resource.end = virt_to_phys(_end) - 1;
320 	code_resource.start = virt_to_phys(_text);
321 	code_resource.end = virt_to_phys(&data_start)-1;
322 
323 	/* We don't know which region the kernel will be in, so try
324 	 * all of them.
325 	 */
326 	for (i = 0; i < sysram_resource_count; i++) {
327 		struct resource *res = &sysram_resources[i];
328 		request_resource(res, &code_resource);
329 		request_resource(res, &data_resource);
330 	}
331 	request_resource(&sysram_resources[0], &pdcdata_resource);
332 
333 	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
334 	pdc_pdt_init();
335 
336 	memblock_allow_resize();
337 	memblock_dump_all();
338 }
339 
340 static bool kernel_set_to_readonly;
341 
342 static void __ref map_pages(unsigned long start_vaddr,
343 			    unsigned long start_paddr, unsigned long size,
344 			    pgprot_t pgprot, int force)
345 {
346 	pmd_t *pmd;
347 	pte_t *pg_table;
348 	unsigned long end_paddr;
349 	unsigned long start_pmd;
350 	unsigned long start_pte;
351 	unsigned long tmp1;
352 	unsigned long tmp2;
353 	unsigned long address;
354 	unsigned long vaddr;
355 	unsigned long ro_start;
356 	unsigned long ro_end;
357 	unsigned long kernel_start, kernel_end;
358 
359 	ro_start = __pa((unsigned long)_text);
360 	ro_end   = __pa((unsigned long)&data_start);
361 	kernel_start = __pa((unsigned long)&__init_begin);
362 	kernel_end  = __pa((unsigned long)&_end);
363 
364 	end_paddr = start_paddr + size;
365 
366 	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
367 	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
368 	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
369 
370 	address = start_paddr;
371 	vaddr = start_vaddr;
372 	while (address < end_paddr) {
373 		pgd_t *pgd = pgd_offset_k(vaddr);
374 		p4d_t *p4d = p4d_offset(pgd, vaddr);
375 		pud_t *pud = pud_offset(p4d, vaddr);
376 
377 #if CONFIG_PGTABLE_LEVELS == 3
378 		if (pud_none(*pud)) {
379 			pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
380 					     PAGE_SIZE << PMD_TABLE_ORDER);
381 			if (!pmd)
382 				panic("pmd allocation failed.\n");
383 			pud_populate(NULL, pud, pmd);
384 		}
385 #endif
386 
387 		pmd = pmd_offset(pud, vaddr);
388 		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
389 			if (pmd_none(*pmd)) {
390 				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
391 				if (!pg_table)
392 					panic("page table allocation failed\n");
393 				pmd_populate_kernel(NULL, pmd, pg_table);
394 			}
395 
396 			pg_table = pte_offset_kernel(pmd, vaddr);
397 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
398 				pte_t pte;
399 				pgprot_t prot;
400 				bool huge = false;
401 
402 				if (force) {
403 					prot = pgprot;
404 				} else if (address < kernel_start || address >= kernel_end) {
405 					/* outside kernel memory */
406 					prot = PAGE_KERNEL;
407 				} else if (!kernel_set_to_readonly) {
408 					/* still initializing, allow writing to RO memory */
409 					prot = PAGE_KERNEL_RWX;
410 					huge = true;
411 				} else if (address >= ro_start) {
412 					/* Code (ro) and Data areas */
413 					prot = (address < ro_end) ?
414 						PAGE_KERNEL_EXEC : PAGE_KERNEL;
415 					huge = true;
416 				} else {
417 					prot = PAGE_KERNEL;
418 				}
419 
420 				pte = __mk_pte(address, prot);
421 				if (huge)
422 					pte = pte_mkhuge(pte);
423 
424 				if (address >= end_paddr)
425 					break;
426 
427 				set_pte(pg_table, pte);
428 
429 				address += PAGE_SIZE;
430 				vaddr += PAGE_SIZE;
431 			}
432 			start_pte = 0;
433 
434 			if (address >= end_paddr)
435 			    break;
436 		}
437 		start_pmd = 0;
438 	}
439 }
440 
441 void __init set_kernel_text_rw(int enable_read_write)
442 {
443 	unsigned long start = (unsigned long) __init_begin;
444 	unsigned long end   = (unsigned long) &data_start;
445 
446 	map_pages(start, __pa(start), end-start,
447 		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
448 
449 	/* force the kernel to see the new page table entries */
450 	flush_cache_all();
451 	flush_tlb_all();
452 }
453 
454 void free_initmem(void)
455 {
456 	unsigned long init_begin = (unsigned long)__init_begin;
457 	unsigned long init_end = (unsigned long)__init_end;
458 	unsigned long kernel_end  = (unsigned long)&_end;
459 
460 	/* Remap kernel text and data, but do not touch init section yet. */
461 	kernel_set_to_readonly = true;
462 	map_pages(init_end, __pa(init_end), kernel_end - init_end,
463 		  PAGE_KERNEL, 0);
464 
465 	/* The init text pages are marked R-X.  We have to
466 	 * flush the icache and mark them RW-
467 	 *
468 	 * Do a dummy remap of the data section first (the data
469 	 * section is already PAGE_KERNEL) to pull in the TLB entries
470 	 * for map_kernel */
471 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
472 		  PAGE_KERNEL_RWX, 1);
473 	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
474 	 * map_pages */
475 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
476 		  PAGE_KERNEL, 1);
477 
478 	/* force the kernel to see the new TLB entries */
479 	__flush_tlb_range(0, init_begin, kernel_end);
480 
481 	/* finally dump all the instructions which were cached, since the
482 	 * pages are no-longer executable */
483 	flush_icache_range(init_begin, init_end);
484 
485 	free_initmem_default(POISON_FREE_INITMEM);
486 
487 	/* set up a new led state on systems shipped LED State panel */
488 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
489 }
490 
491 
492 #ifdef CONFIG_STRICT_KERNEL_RWX
493 void mark_rodata_ro(void)
494 {
495 	/* rodata memory was already mapped with KERNEL_RO access rights by
496            pagetable_init() and map_pages(). No need to do additional stuff here */
497 	unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
498 
499 	pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
500 }
501 #endif
502 
503 
504 /*
505  * Just an arbitrary offset to serve as a "hole" between mapping areas
506  * (between top of physical memory and a potential pcxl dma mapping
507  * area, and below the vmalloc mapping area).
508  *
509  * The current 32K value just means that there will be a 32K "hole"
510  * between mapping areas. That means that  any out-of-bounds memory
511  * accesses will hopefully be caught. The vmalloc() routines leaves
512  * a hole of 4kB between each vmalloced area for the same reason.
513  */
514 
515  /* Leave room for gateway page expansion */
516 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
517 #error KERNEL_MAP_START is in gateway reserved region
518 #endif
519 #define MAP_START (KERNEL_MAP_START)
520 
521 #define VM_MAP_OFFSET  (32*1024)
522 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
523 				     & ~(VM_MAP_OFFSET-1)))
524 
525 void *parisc_vmalloc_start __ro_after_init;
526 EXPORT_SYMBOL(parisc_vmalloc_start);
527 
528 void __init mem_init(void)
529 {
530 	/* Do sanity checks on IPC (compat) structures */
531 	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
532 #ifndef CONFIG_64BIT
533 	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
534 	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
535 	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
536 #endif
537 #ifdef CONFIG_COMPAT
538 	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
539 	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
540 	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
541 	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
542 #endif
543 
544 	/* Do sanity checks on page table constants */
545 	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
546 	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
547 	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
548 	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
549 			> BITS_PER_LONG);
550 #if CONFIG_PGTABLE_LEVELS == 3
551 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
552 #else
553 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
554 #endif
555 
556 #ifdef CONFIG_64BIT
557 	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
558 	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
559 	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
560 #endif
561 
562 	high_memory = __va((max_pfn << PAGE_SHIFT));
563 	set_max_mapnr(max_low_pfn);
564 	memblock_free_all();
565 
566 #ifdef CONFIG_PA11
567 	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
568 		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
569 		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
570 						+ PCXL_DMA_MAP_SIZE);
571 	} else
572 #endif
573 		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
574 
575 #if 0
576 	/*
577 	 * Do not expose the virtual kernel memory layout to userspace.
578 	 * But keep code for debugging purposes.
579 	 */
580 	printk("virtual kernel memory layout:\n"
581 	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
582 	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
583 	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
584 	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
585 	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
586 	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
587 
588 	       (void*)VMALLOC_START, (void*)VMALLOC_END,
589 	       (VMALLOC_END - VMALLOC_START) >> 20,
590 
591 	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
592 	       (unsigned long)(FIXMAP_SIZE / 1024),
593 
594 	       __va(0), high_memory,
595 	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
596 
597 	       __init_begin, __init_end,
598 	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
599 
600 	       _etext, _edata,
601 	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
602 
603 	       _text, _etext,
604 	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
605 #endif
606 }
607 
608 unsigned long *empty_zero_page __ro_after_init;
609 EXPORT_SYMBOL(empty_zero_page);
610 
611 /*
612  * pagetable_init() sets up the page tables
613  *
614  * Note that gateway_init() places the Linux gateway page at page 0.
615  * Since gateway pages cannot be dereferenced this has the desirable
616  * side effect of trapping those pesky NULL-reference errors in the
617  * kernel.
618  */
619 static void __init pagetable_init(void)
620 {
621 	int range;
622 
623 	/* Map each physical memory range to its kernel vaddr */
624 
625 	for (range = 0; range < npmem_ranges; range++) {
626 		unsigned long start_paddr;
627 		unsigned long size;
628 
629 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
630 		size = pmem_ranges[range].pages << PAGE_SHIFT;
631 
632 		map_pages((unsigned long)__va(start_paddr), start_paddr,
633 			  size, PAGE_KERNEL, 0);
634 	}
635 
636 #ifdef CONFIG_BLK_DEV_INITRD
637 	if (initrd_end && initrd_end > mem_limit) {
638 		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
639 		map_pages(initrd_start, __pa(initrd_start),
640 			  initrd_end - initrd_start, PAGE_KERNEL, 0);
641 	}
642 #endif
643 
644 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
645 	if (!empty_zero_page)
646 		panic("zero page allocation failed.\n");
647 
648 }
649 
650 static void __init gateway_init(void)
651 {
652 	unsigned long linux_gateway_page_addr;
653 	/* FIXME: This is 'const' in order to trick the compiler
654 	   into not treating it as DP-relative data. */
655 	extern void * const linux_gateway_page;
656 
657 	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
658 
659 	/*
660 	 * Setup Linux Gateway page.
661 	 *
662 	 * The Linux gateway page will reside in kernel space (on virtual
663 	 * page 0), so it doesn't need to be aliased into user space.
664 	 */
665 
666 	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
667 		  PAGE_SIZE, PAGE_GATEWAY, 1);
668 }
669 
670 static void __init fixmap_init(void)
671 {
672 	unsigned long addr = FIXMAP_START;
673 	unsigned long end = FIXMAP_START + FIXMAP_SIZE;
674 	pgd_t *pgd = pgd_offset_k(addr);
675 	p4d_t *p4d = p4d_offset(pgd, addr);
676 	pud_t *pud = pud_offset(p4d, addr);
677 	pmd_t *pmd;
678 
679 	BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
680 
681 #if CONFIG_PGTABLE_LEVELS == 3
682 	if (pud_none(*pud)) {
683 		pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
684 				     PAGE_SIZE << PMD_TABLE_ORDER);
685 		if (!pmd)
686 			panic("fixmap: pmd allocation failed.\n");
687 		pud_populate(NULL, pud, pmd);
688 	}
689 #endif
690 
691 	pmd = pmd_offset(pud, addr);
692 	do {
693 		pte_t *pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
694 		if (!pte)
695 			panic("fixmap: pte allocation failed.\n");
696 
697 		pmd_populate_kernel(&init_mm, pmd, pte);
698 
699 		addr += PAGE_SIZE;
700 	} while (addr < end);
701 }
702 
703 static void __init parisc_bootmem_free(void)
704 {
705 	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
706 
707 	max_zone_pfn[0] = memblock_end_of_DRAM();
708 
709 	free_area_init(max_zone_pfn);
710 }
711 
712 void __init paging_init(void)
713 {
714 	setup_bootmem();
715 	pagetable_init();
716 	gateway_init();
717 	fixmap_init();
718 	flush_cache_all_local(); /* start with known state */
719 	flush_tlb_all_local(NULL);
720 
721 	sparse_init();
722 	parisc_bootmem_free();
723 }
724 
725 static void alloc_btlb(unsigned long start, unsigned long end, int *slot,
726 			unsigned long entry_info)
727 {
728 	const int slot_max = btlb_info.fixed_range_info.num_comb;
729 	int min_num_pages = btlb_info.min_size;
730 	unsigned long size;
731 
732 	/* map at minimum 4 pages */
733 	if (min_num_pages < 4)
734 		min_num_pages = 4;
735 
736 	size = HUGEPAGE_SIZE;
737 	while (start < end && *slot < slot_max && size >= PAGE_SIZE) {
738 		/* starting address must have same alignment as size! */
739 		/* if correctly aligned and fits in double size, increase */
740 		if (((start & (2 * size - 1)) == 0) &&
741 		    (end - start) >= (2 * size)) {
742 			size <<= 1;
743 			continue;
744 		}
745 		/* if current size alignment is too big, try smaller size */
746 		if ((start & (size - 1)) != 0) {
747 			size >>= 1;
748 			continue;
749 		}
750 		if ((end - start) >= size) {
751 			if ((size >> PAGE_SHIFT) >= min_num_pages)
752 				pdc_btlb_insert(start >> PAGE_SHIFT, __pa(start) >> PAGE_SHIFT,
753 					size >> PAGE_SHIFT, entry_info, *slot);
754 			(*slot)++;
755 			start += size;
756 			continue;
757 		}
758 		size /= 2;
759 		continue;
760 	}
761 }
762 
763 void btlb_init_per_cpu(void)
764 {
765 	unsigned long s, t, e;
766 	int slot;
767 
768 	/* BTLBs are not available on 64-bit CPUs */
769 	if (IS_ENABLED(CONFIG_PA20))
770 		return;
771 	else if (pdc_btlb_info(&btlb_info) < 0) {
772 		memset(&btlb_info, 0, sizeof btlb_info);
773 	}
774 
775 	/* insert BLTLBs for code and data segments */
776 	s = (uintptr_t) dereference_function_descriptor(&_stext);
777 	e = (uintptr_t) dereference_function_descriptor(&_etext);
778 	t = (uintptr_t) dereference_function_descriptor(&_sdata);
779 	BUG_ON(t != e);
780 
781 	/* code segments */
782 	slot = 0;
783 	alloc_btlb(s, e, &slot, 0x13800000);
784 
785 	/* sanity check */
786 	t = (uintptr_t) dereference_function_descriptor(&_edata);
787 	e = (uintptr_t) dereference_function_descriptor(&__bss_start);
788 	BUG_ON(t != e);
789 
790 	/* data segments */
791 	s = (uintptr_t) dereference_function_descriptor(&_sdata);
792 	e = (uintptr_t) dereference_function_descriptor(&__bss_stop);
793 	alloc_btlb(s, e, &slot, 0x11800000);
794 }
795 
796 #ifdef CONFIG_PA20
797 
798 /*
799  * Currently, all PA20 chips have 18 bit protection IDs, which is the
800  * limiting factor (space ids are 32 bits).
801  */
802 
803 #define NR_SPACE_IDS 262144
804 
805 #else
806 
807 /*
808  * Currently we have a one-to-one relationship between space IDs and
809  * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
810  * support 15 bit protection IDs, so that is the limiting factor.
811  * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
812  * probably not worth the effort for a special case here.
813  */
814 
815 #define NR_SPACE_IDS 32768
816 
817 #endif  /* !CONFIG_PA20 */
818 
819 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
820 #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
821 
822 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
823 static unsigned long dirty_space_id[SID_ARRAY_SIZE];
824 static unsigned long space_id_index;
825 static unsigned long free_space_ids = NR_SPACE_IDS - 1;
826 static unsigned long dirty_space_ids;
827 
828 static DEFINE_SPINLOCK(sid_lock);
829 
830 unsigned long alloc_sid(void)
831 {
832 	unsigned long index;
833 
834 	spin_lock(&sid_lock);
835 
836 	if (free_space_ids == 0) {
837 		if (dirty_space_ids != 0) {
838 			spin_unlock(&sid_lock);
839 			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
840 			spin_lock(&sid_lock);
841 		}
842 		BUG_ON(free_space_ids == 0);
843 	}
844 
845 	free_space_ids--;
846 
847 	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
848 	space_id[BIT_WORD(index)] |= BIT_MASK(index);
849 	space_id_index = index;
850 
851 	spin_unlock(&sid_lock);
852 
853 	return index << SPACEID_SHIFT;
854 }
855 
856 void free_sid(unsigned long spaceid)
857 {
858 	unsigned long index = spaceid >> SPACEID_SHIFT;
859 	unsigned long *dirty_space_offset, mask;
860 
861 	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
862 	mask = BIT_MASK(index);
863 
864 	spin_lock(&sid_lock);
865 
866 	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
867 
868 	*dirty_space_offset |= mask;
869 	dirty_space_ids++;
870 
871 	spin_unlock(&sid_lock);
872 }
873 
874 
875 #ifdef CONFIG_SMP
876 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
877 {
878 	int i;
879 
880 	/* NOTE: sid_lock must be held upon entry */
881 
882 	*ndirtyptr = dirty_space_ids;
883 	if (dirty_space_ids != 0) {
884 	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
885 		dirty_array[i] = dirty_space_id[i];
886 		dirty_space_id[i] = 0;
887 	    }
888 	    dirty_space_ids = 0;
889 	}
890 
891 	return;
892 }
893 
894 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
895 {
896 	int i;
897 
898 	/* NOTE: sid_lock must be held upon entry */
899 
900 	if (ndirty != 0) {
901 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
902 			space_id[i] ^= dirty_array[i];
903 		}
904 
905 		free_space_ids += ndirty;
906 		space_id_index = 0;
907 	}
908 }
909 
910 #else /* CONFIG_SMP */
911 
912 static void recycle_sids(void)
913 {
914 	int i;
915 
916 	/* NOTE: sid_lock must be held upon entry */
917 
918 	if (dirty_space_ids != 0) {
919 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
920 			space_id[i] ^= dirty_space_id[i];
921 			dirty_space_id[i] = 0;
922 		}
923 
924 		free_space_ids += dirty_space_ids;
925 		dirty_space_ids = 0;
926 		space_id_index = 0;
927 	}
928 }
929 #endif
930 
931 /*
932  * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
933  * purged, we can safely reuse the space ids that were released but
934  * not flushed from the tlb.
935  */
936 
937 #ifdef CONFIG_SMP
938 
939 static unsigned long recycle_ndirty;
940 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
941 static unsigned int recycle_inuse;
942 
943 void flush_tlb_all(void)
944 {
945 	int do_recycle;
946 
947 	do_recycle = 0;
948 	spin_lock(&sid_lock);
949 	__inc_irq_stat(irq_tlb_count);
950 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
951 	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
952 	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
953 	    recycle_inuse++;
954 	    do_recycle++;
955 	}
956 	spin_unlock(&sid_lock);
957 	on_each_cpu(flush_tlb_all_local, NULL, 1);
958 	if (do_recycle) {
959 	    spin_lock(&sid_lock);
960 	    recycle_sids(recycle_ndirty,recycle_dirty_array);
961 	    recycle_inuse = 0;
962 	    spin_unlock(&sid_lock);
963 	}
964 }
965 #else
966 void flush_tlb_all(void)
967 {
968 	spin_lock(&sid_lock);
969 	__inc_irq_stat(irq_tlb_count);
970 	flush_tlb_all_local(NULL);
971 	recycle_sids();
972 	spin_unlock(&sid_lock);
973 }
974 #endif
975 
976 static const pgprot_t protection_map[16] = {
977 	[VM_NONE]					= PAGE_NONE,
978 	[VM_READ]					= PAGE_READONLY,
979 	[VM_WRITE]					= PAGE_NONE,
980 	[VM_WRITE | VM_READ]				= PAGE_READONLY,
981 	[VM_EXEC]					= PAGE_EXECREAD,
982 	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
983 	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
984 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
985 	[VM_SHARED]					= PAGE_NONE,
986 	[VM_SHARED | VM_READ]				= PAGE_READONLY,
987 	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
988 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
989 	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
990 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
991 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
992 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
993 };
994 DECLARE_VM_GET_PAGE_PROT
995