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 
36 extern int  data_start;
37 extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
38 
39 #if CONFIG_PGTABLE_LEVELS == 3
40 pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
41 #endif
42 
43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
44 pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
45 
46 static struct resource data_resource = {
47 	.name	= "Kernel data",
48 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
49 };
50 
51 static struct resource code_resource = {
52 	.name	= "Kernel code",
53 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
54 };
55 
56 static struct resource pdcdata_resource = {
57 	.name	= "PDC data (Page Zero)",
58 	.start	= 0,
59 	.end	= 0x9ff,
60 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
61 };
62 
63 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
64 
65 /* The following array is initialized from the firmware specific
66  * information retrieved in kernel/inventory.c.
67  */
68 
69 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
70 int npmem_ranges __initdata;
71 
72 #ifdef CONFIG_64BIT
73 #define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
74 #else /* !CONFIG_64BIT */
75 #define MAX_MEM         (3584U*1024U*1024U)
76 #endif /* !CONFIG_64BIT */
77 
78 static unsigned long mem_limit __read_mostly = MAX_MEM;
79 
mem_limit_func(void)80 static void __init mem_limit_func(void)
81 {
82 	char *cp, *end;
83 	unsigned long limit;
84 
85 	/* We need this before __setup() functions are called */
86 
87 	limit = MAX_MEM;
88 	for (cp = boot_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 
setup_bootmem(void)109 static void __init setup_bootmem(void)
110 {
111 	unsigned long mem_max;
112 #ifndef CONFIG_SPARSEMEM
113 	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
114 	int npmem_holes;
115 #endif
116 	int i, sysram_resource_count;
117 
118 	disable_sr_hashing(); /* Turn off space register hashing */
119 
120 	/*
121 	 * Sort the ranges. Since the number of ranges is typically
122 	 * small, and performance is not an issue here, just do
123 	 * a simple insertion sort.
124 	 */
125 
126 	for (i = 1; i < npmem_ranges; i++) {
127 		int j;
128 
129 		for (j = i; j > 0; j--) {
130 			if (pmem_ranges[j-1].start_pfn <
131 			    pmem_ranges[j].start_pfn) {
132 
133 				break;
134 			}
135 			swap(pmem_ranges[j-1], pmem_ranges[j]);
136 		}
137 	}
138 
139 #ifndef CONFIG_SPARSEMEM
140 	/*
141 	 * Throw out ranges that are too far apart (controlled by
142 	 * MAX_GAP).
143 	 */
144 
145 	for (i = 1; i < npmem_ranges; i++) {
146 		if (pmem_ranges[i].start_pfn -
147 			(pmem_ranges[i-1].start_pfn +
148 			 pmem_ranges[i-1].pages) > MAX_GAP) {
149 			npmem_ranges = i;
150 			printk("Large gap in memory detected (%ld pages). "
151 			       "Consider turning on CONFIG_SPARSEMEM\n",
152 			       pmem_ranges[i].start_pfn -
153 			       (pmem_ranges[i-1].start_pfn +
154 			        pmem_ranges[i-1].pages));
155 			break;
156 		}
157 	}
158 #endif
159 
160 	/* Print the memory ranges */
161 	pr_info("Memory Ranges:\n");
162 
163 	for (i = 0; i < npmem_ranges; i++) {
164 		struct resource *res = &sysram_resources[i];
165 		unsigned long start;
166 		unsigned long size;
167 
168 		size = (pmem_ranges[i].pages << PAGE_SHIFT);
169 		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
170 		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
171 			i, start, start + (size - 1), size >> 20);
172 
173 		/* request memory resource */
174 		res->name = "System RAM";
175 		res->start = start;
176 		res->end = start + size - 1;
177 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
178 		request_resource(&iomem_resource, res);
179 	}
180 
181 	sysram_resource_count = npmem_ranges;
182 
183 	/*
184 	 * For 32 bit kernels we limit the amount of memory we can
185 	 * support, in order to preserve enough kernel address space
186 	 * for other purposes. For 64 bit kernels we don't normally
187 	 * limit the memory, but this mechanism can be used to
188 	 * artificially limit the amount of memory (and it is written
189 	 * to work with multiple memory ranges).
190 	 */
191 
192 	mem_limit_func();       /* check for "mem=" argument */
193 
194 	mem_max = 0;
195 	for (i = 0; i < npmem_ranges; i++) {
196 		unsigned long rsize;
197 
198 		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
199 		if ((mem_max + rsize) > mem_limit) {
200 			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
201 			if (mem_max == mem_limit)
202 				npmem_ranges = i;
203 			else {
204 				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
205 						       - (mem_max >> PAGE_SHIFT);
206 				npmem_ranges = i + 1;
207 				mem_max = mem_limit;
208 			}
209 			break;
210 		}
211 		mem_max += rsize;
212 	}
213 
214 	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
215 
216 #ifndef CONFIG_SPARSEMEM
217 	/* Merge the ranges, keeping track of the holes */
218 	{
219 		unsigned long end_pfn;
220 		unsigned long hole_pages;
221 
222 		npmem_holes = 0;
223 		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
224 		for (i = 1; i < npmem_ranges; i++) {
225 
226 			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
227 			if (hole_pages) {
228 				pmem_holes[npmem_holes].start_pfn = end_pfn;
229 				pmem_holes[npmem_holes++].pages = hole_pages;
230 				end_pfn += hole_pages;
231 			}
232 			end_pfn += pmem_ranges[i].pages;
233 		}
234 
235 		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
236 		npmem_ranges = 1;
237 	}
238 #endif
239 
240 	/*
241 	 * Initialize and free the full range of memory in each range.
242 	 */
243 
244 	max_pfn = 0;
245 	for (i = 0; i < npmem_ranges; i++) {
246 		unsigned long start_pfn;
247 		unsigned long npages;
248 		unsigned long start;
249 		unsigned long size;
250 
251 		start_pfn = pmem_ranges[i].start_pfn;
252 		npages = pmem_ranges[i].pages;
253 
254 		start = start_pfn << PAGE_SHIFT;
255 		size = npages << PAGE_SHIFT;
256 
257 		/* add system RAM memblock */
258 		memblock_add(start, size);
259 
260 		if ((start_pfn + npages) > max_pfn)
261 			max_pfn = start_pfn + npages;
262 	}
263 
264 	/*
265 	 * We can't use memblock top-down allocations because we only
266 	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
267 	 * the assembly bootup code.
268 	 */
269 	memblock_set_bottom_up(true);
270 
271 	/* IOMMU is always used to access "high mem" on those boxes
272 	 * that can support enough mem that a PCI device couldn't
273 	 * directly DMA to any physical addresses.
274 	 * ISA DMA support will need to revisit this.
275 	 */
276 	max_low_pfn = max_pfn;
277 
278 	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
279 
280 #define PDC_CONSOLE_IO_IODC_SIZE 32768
281 
282 	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
283 				PDC_CONSOLE_IO_IODC_SIZE));
284 	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
285 			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
286 
287 #ifndef CONFIG_SPARSEMEM
288 
289 	/* reserve the holes */
290 
291 	for (i = 0; i < npmem_holes; i++) {
292 		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
293 				(pmem_holes[i].pages << PAGE_SHIFT));
294 	}
295 #endif
296 
297 #ifdef CONFIG_BLK_DEV_INITRD
298 	if (initrd_start) {
299 		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
300 		if (__pa(initrd_start) < mem_max) {
301 			unsigned long initrd_reserve;
302 
303 			if (__pa(initrd_end) > mem_max) {
304 				initrd_reserve = mem_max - __pa(initrd_start);
305 			} else {
306 				initrd_reserve = initrd_end - initrd_start;
307 			}
308 			initrd_below_start_ok = 1;
309 			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
310 
311 			memblock_reserve(__pa(initrd_start), initrd_reserve);
312 		}
313 	}
314 #endif
315 
316 	data_resource.start =  virt_to_phys(&data_start);
317 	data_resource.end = virt_to_phys(_end) - 1;
318 	code_resource.start = virt_to_phys(_text);
319 	code_resource.end = virt_to_phys(&data_start)-1;
320 
321 	/* We don't know which region the kernel will be in, so try
322 	 * all of them.
323 	 */
324 	for (i = 0; i < sysram_resource_count; i++) {
325 		struct resource *res = &sysram_resources[i];
326 		request_resource(res, &code_resource);
327 		request_resource(res, &data_resource);
328 	}
329 	request_resource(&sysram_resources[0], &pdcdata_resource);
330 
331 	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
332 	pdc_pdt_init();
333 
334 	memblock_allow_resize();
335 	memblock_dump_all();
336 }
337 
338 static bool kernel_set_to_readonly;
339 
map_pages(unsigned long start_vaddr,unsigned long start_paddr,unsigned long size,pgprot_t pgprot,int force)340 static void __ref map_pages(unsigned long start_vaddr,
341 			    unsigned long start_paddr, unsigned long size,
342 			    pgprot_t pgprot, int force)
343 {
344 	pmd_t *pmd;
345 	pte_t *pg_table;
346 	unsigned long end_paddr;
347 	unsigned long start_pmd;
348 	unsigned long start_pte;
349 	unsigned long tmp1;
350 	unsigned long tmp2;
351 	unsigned long address;
352 	unsigned long vaddr;
353 	unsigned long ro_start;
354 	unsigned long ro_end;
355 	unsigned long kernel_start, kernel_end;
356 
357 	ro_start = __pa((unsigned long)_text);
358 	ro_end   = __pa((unsigned long)&data_start);
359 	kernel_start = __pa((unsigned long)&__init_begin);
360 	kernel_end  = __pa((unsigned long)&_end);
361 
362 	end_paddr = start_paddr + size;
363 
364 	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
365 	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
366 	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
367 
368 	address = start_paddr;
369 	vaddr = start_vaddr;
370 	while (address < end_paddr) {
371 		pgd_t *pgd = pgd_offset_k(vaddr);
372 		p4d_t *p4d = p4d_offset(pgd, vaddr);
373 		pud_t *pud = pud_offset(p4d, vaddr);
374 
375 #if CONFIG_PGTABLE_LEVELS == 3
376 		if (pud_none(*pud)) {
377 			pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
378 					     PAGE_SIZE << PMD_TABLE_ORDER);
379 			if (!pmd)
380 				panic("pmd allocation failed.\n");
381 			pud_populate(NULL, pud, pmd);
382 		}
383 #endif
384 
385 		pmd = pmd_offset(pud, vaddr);
386 		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
387 			if (pmd_none(*pmd)) {
388 				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
389 				if (!pg_table)
390 					panic("page table allocation failed\n");
391 				pmd_populate_kernel(NULL, pmd, pg_table);
392 			}
393 
394 			pg_table = pte_offset_kernel(pmd, vaddr);
395 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
396 				pte_t pte;
397 				pgprot_t prot;
398 				bool huge = false;
399 
400 				if (force) {
401 					prot = pgprot;
402 				} else if (address < kernel_start || address >= kernel_end) {
403 					/* outside kernel memory */
404 					prot = PAGE_KERNEL;
405 				} else if (!kernel_set_to_readonly) {
406 					/* still initializing, allow writing to RO memory */
407 					prot = PAGE_KERNEL_RWX;
408 					huge = true;
409 				} else if (address >= ro_start) {
410 					/* Code (ro) and Data areas */
411 					prot = (address < ro_end) ?
412 						PAGE_KERNEL_EXEC : PAGE_KERNEL;
413 					huge = true;
414 				} else {
415 					prot = PAGE_KERNEL;
416 				}
417 
418 				pte = __mk_pte(address, prot);
419 				if (huge)
420 					pte = pte_mkhuge(pte);
421 
422 				if (address >= end_paddr)
423 					break;
424 
425 				set_pte(pg_table, pte);
426 
427 				address += PAGE_SIZE;
428 				vaddr += PAGE_SIZE;
429 			}
430 			start_pte = 0;
431 
432 			if (address >= end_paddr)
433 			    break;
434 		}
435 		start_pmd = 0;
436 	}
437 }
438 
set_kernel_text_rw(int enable_read_write)439 void __init set_kernel_text_rw(int enable_read_write)
440 {
441 	unsigned long start = (unsigned long) __init_begin;
442 	unsigned long end   = (unsigned long) &data_start;
443 
444 	map_pages(start, __pa(start), end-start,
445 		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
446 
447 	/* force the kernel to see the new page table entries */
448 	flush_cache_all();
449 	flush_tlb_all();
450 }
451 
free_initmem(void)452 void free_initmem(void)
453 {
454 	unsigned long init_begin = (unsigned long)__init_begin;
455 	unsigned long init_end = (unsigned long)__init_end;
456 	unsigned long kernel_end  = (unsigned long)&_end;
457 
458 	/* Remap kernel text and data, but do not touch init section yet. */
459 	kernel_set_to_readonly = true;
460 	map_pages(init_end, __pa(init_end), kernel_end - init_end,
461 		  PAGE_KERNEL, 0);
462 
463 	/* The init text pages are marked R-X.  We have to
464 	 * flush the icache and mark them RW-
465 	 *
466 	 * Do a dummy remap of the data section first (the data
467 	 * section is already PAGE_KERNEL) to pull in the TLB entries
468 	 * for map_kernel */
469 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
470 		  PAGE_KERNEL_RWX, 1);
471 	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
472 	 * map_pages */
473 	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
474 		  PAGE_KERNEL, 1);
475 
476 	/* force the kernel to see the new TLB entries */
477 	__flush_tlb_range(0, init_begin, kernel_end);
478 
479 	/* finally dump all the instructions which were cached, since the
480 	 * pages are no-longer executable */
481 	flush_icache_range(init_begin, init_end);
482 
483 	free_initmem_default(POISON_FREE_INITMEM);
484 
485 	/* set up a new led state on systems shipped LED State panel */
486 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
487 }
488 
489 
490 #ifdef CONFIG_STRICT_KERNEL_RWX
mark_rodata_ro(void)491 void mark_rodata_ro(void)
492 {
493 	/* rodata memory was already mapped with KERNEL_RO access rights by
494            pagetable_init() and map_pages(). No need to do additional stuff here */
495 	unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
496 
497 	pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
498 }
499 #endif
500 
501 
502 /*
503  * Just an arbitrary offset to serve as a "hole" between mapping areas
504  * (between top of physical memory and a potential pcxl dma mapping
505  * area, and below the vmalloc mapping area).
506  *
507  * The current 32K value just means that there will be a 32K "hole"
508  * between mapping areas. That means that  any out-of-bounds memory
509  * accesses will hopefully be caught. The vmalloc() routines leaves
510  * a hole of 4kB between each vmalloced area for the same reason.
511  */
512 
513  /* Leave room for gateway page expansion */
514 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
515 #error KERNEL_MAP_START is in gateway reserved region
516 #endif
517 #define MAP_START (KERNEL_MAP_START)
518 
519 #define VM_MAP_OFFSET  (32*1024)
520 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
521 				     & ~(VM_MAP_OFFSET-1)))
522 
523 void *parisc_vmalloc_start __ro_after_init;
524 EXPORT_SYMBOL(parisc_vmalloc_start);
525 
526 #ifdef CONFIG_PA11
527 unsigned long pcxl_dma_start __ro_after_init;
528 #endif
529 
mem_init(void)530 void __init mem_init(void)
531 {
532 	/* Do sanity checks on IPC (compat) structures */
533 	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
534 #ifndef CONFIG_64BIT
535 	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
536 	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
537 	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
538 #endif
539 #ifdef CONFIG_COMPAT
540 	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
541 	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
542 	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
543 	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
544 #endif
545 
546 	/* Do sanity checks on page table constants */
547 	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
548 	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
549 	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
550 	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
551 			> BITS_PER_LONG);
552 #if CONFIG_PGTABLE_LEVELS == 3
553 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
554 #else
555 	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
556 #endif
557 
558 #ifdef CONFIG_64BIT
559 	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
560 	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
561 	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
562 #endif
563 
564 	high_memory = __va((max_pfn << PAGE_SHIFT));
565 	set_max_mapnr(max_low_pfn);
566 	memblock_free_all();
567 
568 #ifdef CONFIG_PA11
569 	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
570 		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
571 		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
572 						+ PCXL_DMA_MAP_SIZE);
573 	} else
574 #endif
575 		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
576 
577 #if 0
578 	/*
579 	 * Do not expose the virtual kernel memory layout to userspace.
580 	 * But keep code for debugging purposes.
581 	 */
582 	printk("virtual kernel memory layout:\n"
583 	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
584 	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
585 	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
586 	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
587 	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
588 	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
589 
590 	       (void*)VMALLOC_START, (void*)VMALLOC_END,
591 	       (VMALLOC_END - VMALLOC_START) >> 20,
592 
593 	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
594 	       (unsigned long)(FIXMAP_SIZE / 1024),
595 
596 	       __va(0), high_memory,
597 	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
598 
599 	       __init_begin, __init_end,
600 	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
601 
602 	       _etext, _edata,
603 	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
604 
605 	       _text, _etext,
606 	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
607 #endif
608 }
609 
610 unsigned long *empty_zero_page __ro_after_init;
611 EXPORT_SYMBOL(empty_zero_page);
612 
613 /*
614  * pagetable_init() sets up the page tables
615  *
616  * Note that gateway_init() places the Linux gateway page at page 0.
617  * Since gateway pages cannot be dereferenced this has the desirable
618  * side effect of trapping those pesky NULL-reference errors in the
619  * kernel.
620  */
pagetable_init(void)621 static void __init pagetable_init(void)
622 {
623 	int range;
624 
625 	/* Map each physical memory range to its kernel vaddr */
626 
627 	for (range = 0; range < npmem_ranges; range++) {
628 		unsigned long start_paddr;
629 		unsigned long end_paddr;
630 		unsigned long size;
631 
632 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
633 		size = pmem_ranges[range].pages << PAGE_SHIFT;
634 		end_paddr = start_paddr + size;
635 
636 		map_pages((unsigned long)__va(start_paddr), start_paddr,
637 			  size, PAGE_KERNEL, 0);
638 	}
639 
640 #ifdef CONFIG_BLK_DEV_INITRD
641 	if (initrd_end && initrd_end > mem_limit) {
642 		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
643 		map_pages(initrd_start, __pa(initrd_start),
644 			  initrd_end - initrd_start, PAGE_KERNEL, 0);
645 	}
646 #endif
647 
648 	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
649 	if (!empty_zero_page)
650 		panic("zero page allocation failed.\n");
651 
652 }
653 
gateway_init(void)654 static void __init gateway_init(void)
655 {
656 	unsigned long linux_gateway_page_addr;
657 	/* FIXME: This is 'const' in order to trick the compiler
658 	   into not treating it as DP-relative data. */
659 	extern void * const linux_gateway_page;
660 
661 	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
662 
663 	/*
664 	 * Setup Linux Gateway page.
665 	 *
666 	 * The Linux gateway page will reside in kernel space (on virtual
667 	 * page 0), so it doesn't need to be aliased into user space.
668 	 */
669 
670 	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
671 		  PAGE_SIZE, PAGE_GATEWAY, 1);
672 }
673 
parisc_bootmem_free(void)674 static void __init parisc_bootmem_free(void)
675 {
676 	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
677 
678 	max_zone_pfn[0] = memblock_end_of_DRAM();
679 
680 	free_area_init(max_zone_pfn);
681 }
682 
paging_init(void)683 void __init paging_init(void)
684 {
685 	setup_bootmem();
686 	pagetable_init();
687 	gateway_init();
688 	flush_cache_all_local(); /* start with known state */
689 	flush_tlb_all_local(NULL);
690 
691 	sparse_init();
692 	parisc_bootmem_free();
693 }
694 
695 #ifdef CONFIG_PA20
696 
697 /*
698  * Currently, all PA20 chips have 18 bit protection IDs, which is the
699  * limiting factor (space ids are 32 bits).
700  */
701 
702 #define NR_SPACE_IDS 262144
703 
704 #else
705 
706 /*
707  * Currently we have a one-to-one relationship between space IDs and
708  * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
709  * support 15 bit protection IDs, so that is the limiting factor.
710  * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
711  * probably not worth the effort for a special case here.
712  */
713 
714 #define NR_SPACE_IDS 32768
715 
716 #endif  /* !CONFIG_PA20 */
717 
718 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
719 #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
720 
721 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
722 static unsigned long dirty_space_id[SID_ARRAY_SIZE];
723 static unsigned long space_id_index;
724 static unsigned long free_space_ids = NR_SPACE_IDS - 1;
725 static unsigned long dirty_space_ids = 0;
726 
727 static DEFINE_SPINLOCK(sid_lock);
728 
alloc_sid(void)729 unsigned long alloc_sid(void)
730 {
731 	unsigned long index;
732 
733 	spin_lock(&sid_lock);
734 
735 	if (free_space_ids == 0) {
736 		if (dirty_space_ids != 0) {
737 			spin_unlock(&sid_lock);
738 			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
739 			spin_lock(&sid_lock);
740 		}
741 		BUG_ON(free_space_ids == 0);
742 	}
743 
744 	free_space_ids--;
745 
746 	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
747 	space_id[BIT_WORD(index)] |= BIT_MASK(index);
748 	space_id_index = index;
749 
750 	spin_unlock(&sid_lock);
751 
752 	return index << SPACEID_SHIFT;
753 }
754 
free_sid(unsigned long spaceid)755 void free_sid(unsigned long spaceid)
756 {
757 	unsigned long index = spaceid >> SPACEID_SHIFT;
758 	unsigned long *dirty_space_offset, mask;
759 
760 	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
761 	mask = BIT_MASK(index);
762 
763 	spin_lock(&sid_lock);
764 
765 	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
766 
767 	*dirty_space_offset |= mask;
768 	dirty_space_ids++;
769 
770 	spin_unlock(&sid_lock);
771 }
772 
773 
774 #ifdef CONFIG_SMP
get_dirty_sids(unsigned long * ndirtyptr,unsigned long * dirty_array)775 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
776 {
777 	int i;
778 
779 	/* NOTE: sid_lock must be held upon entry */
780 
781 	*ndirtyptr = dirty_space_ids;
782 	if (dirty_space_ids != 0) {
783 	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
784 		dirty_array[i] = dirty_space_id[i];
785 		dirty_space_id[i] = 0;
786 	    }
787 	    dirty_space_ids = 0;
788 	}
789 
790 	return;
791 }
792 
recycle_sids(unsigned long ndirty,unsigned long * dirty_array)793 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
794 {
795 	int i;
796 
797 	/* NOTE: sid_lock must be held upon entry */
798 
799 	if (ndirty != 0) {
800 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
801 			space_id[i] ^= dirty_array[i];
802 		}
803 
804 		free_space_ids += ndirty;
805 		space_id_index = 0;
806 	}
807 }
808 
809 #else /* CONFIG_SMP */
810 
recycle_sids(void)811 static void recycle_sids(void)
812 {
813 	int i;
814 
815 	/* NOTE: sid_lock must be held upon entry */
816 
817 	if (dirty_space_ids != 0) {
818 		for (i = 0; i < SID_ARRAY_SIZE; i++) {
819 			space_id[i] ^= dirty_space_id[i];
820 			dirty_space_id[i] = 0;
821 		}
822 
823 		free_space_ids += dirty_space_ids;
824 		dirty_space_ids = 0;
825 		space_id_index = 0;
826 	}
827 }
828 #endif
829 
830 /*
831  * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
832  * purged, we can safely reuse the space ids that were released but
833  * not flushed from the tlb.
834  */
835 
836 #ifdef CONFIG_SMP
837 
838 static unsigned long recycle_ndirty;
839 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
840 static unsigned int recycle_inuse;
841 
flush_tlb_all(void)842 void flush_tlb_all(void)
843 {
844 	int do_recycle;
845 
846 	do_recycle = 0;
847 	spin_lock(&sid_lock);
848 	__inc_irq_stat(irq_tlb_count);
849 	if (dirty_space_ids > RECYCLE_THRESHOLD) {
850 	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
851 	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
852 	    recycle_inuse++;
853 	    do_recycle++;
854 	}
855 	spin_unlock(&sid_lock);
856 	on_each_cpu(flush_tlb_all_local, NULL, 1);
857 	if (do_recycle) {
858 	    spin_lock(&sid_lock);
859 	    recycle_sids(recycle_ndirty,recycle_dirty_array);
860 	    recycle_inuse = 0;
861 	    spin_unlock(&sid_lock);
862 	}
863 }
864 #else
flush_tlb_all(void)865 void flush_tlb_all(void)
866 {
867 	spin_lock(&sid_lock);
868 	__inc_irq_stat(irq_tlb_count);
869 	flush_tlb_all_local(NULL);
870 	recycle_sids();
871 	spin_unlock(&sid_lock);
872 }
873 #endif
874