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  
37  extern int  data_start;
38  extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
39  
40  #if CONFIG_PGTABLE_LEVELS == 3
41  pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
42  #endif
43  
44  pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
45  pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
46  
47  static struct resource data_resource = {
48  	.name	= "Kernel data",
49  	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
50  };
51  
52  static struct resource code_resource = {
53  	.name	= "Kernel code",
54  	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
55  };
56  
57  static struct resource pdcdata_resource = {
58  	.name	= "PDC data (Page Zero)",
59  	.start	= 0,
60  	.end	= 0x9ff,
61  	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
62  };
63  
64  static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
65  
66  /* The following array is initialized from the firmware specific
67   * information retrieved in kernel/inventory.c.
68   */
69  
70  physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
71  int npmem_ranges __initdata;
72  
73  #ifdef CONFIG_64BIT
74  #define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
75  #else /* !CONFIG_64BIT */
76  #define MAX_MEM         (3584U*1024U*1024U)
77  #endif /* !CONFIG_64BIT */
78  
79  static unsigned long mem_limit __read_mostly = MAX_MEM;
80  
mem_limit_func(void)81  static void __init mem_limit_func(void)
82  {
83  	char *cp, *end;
84  	unsigned long limit;
85  
86  	/* We need this before __setup() functions are called */
87  
88  	limit = MAX_MEM;
89  	for (cp = boot_command_line; *cp; ) {
90  		if (memcmp(cp, "mem=", 4) == 0) {
91  			cp += 4;
92  			limit = memparse(cp, &end);
93  			if (end != cp)
94  				break;
95  			cp = end;
96  		} else {
97  			while (*cp != ' ' && *cp)
98  				++cp;
99  			while (*cp == ' ')
100  				++cp;
101  		}
102  	}
103  
104  	if (limit < mem_limit)
105  		mem_limit = limit;
106  }
107  
108  #define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
109  
setup_bootmem(void)110  static void __init setup_bootmem(void)
111  {
112  	unsigned long mem_max;
113  #ifndef CONFIG_SPARSEMEM
114  	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
115  	int npmem_holes;
116  #endif
117  	int i, sysram_resource_count;
118  
119  	disable_sr_hashing(); /* Turn off space register hashing */
120  
121  	/*
122  	 * Sort the ranges. Since the number of ranges is typically
123  	 * small, and performance is not an issue here, just do
124  	 * a simple insertion sort.
125  	 */
126  
127  	for (i = 1; i < npmem_ranges; i++) {
128  		int j;
129  
130  		for (j = i; j > 0; j--) {
131  			if (pmem_ranges[j-1].start_pfn <
132  			    pmem_ranges[j].start_pfn) {
133  
134  				break;
135  			}
136  			swap(pmem_ranges[j-1], pmem_ranges[j]);
137  		}
138  	}
139  
140  #ifndef CONFIG_SPARSEMEM
141  	/*
142  	 * Throw out ranges that are too far apart (controlled by
143  	 * MAX_GAP).
144  	 */
145  
146  	for (i = 1; i < npmem_ranges; i++) {
147  		if (pmem_ranges[i].start_pfn -
148  			(pmem_ranges[i-1].start_pfn +
149  			 pmem_ranges[i-1].pages) > MAX_GAP) {
150  			npmem_ranges = i;
151  			printk("Large gap in memory detected (%ld pages). "
152  			       "Consider turning on CONFIG_SPARSEMEM\n",
153  			       pmem_ranges[i].start_pfn -
154  			       (pmem_ranges[i-1].start_pfn +
155  			        pmem_ranges[i-1].pages));
156  			break;
157  		}
158  	}
159  #endif
160  
161  	/* Print the memory ranges */
162  	pr_info("Memory Ranges:\n");
163  
164  	for (i = 0; i < npmem_ranges; i++) {
165  		struct resource *res = &sysram_resources[i];
166  		unsigned long start;
167  		unsigned long size;
168  
169  		size = (pmem_ranges[i].pages << PAGE_SHIFT);
170  		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
171  		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
172  			i, start, start + (size - 1), size >> 20);
173  
174  		/* request memory resource */
175  		res->name = "System RAM";
176  		res->start = start;
177  		res->end = start + size - 1;
178  		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
179  		request_resource(&iomem_resource, res);
180  	}
181  
182  	sysram_resource_count = npmem_ranges;
183  
184  	/*
185  	 * For 32 bit kernels we limit the amount of memory we can
186  	 * support, in order to preserve enough kernel address space
187  	 * for other purposes. For 64 bit kernels we don't normally
188  	 * limit the memory, but this mechanism can be used to
189  	 * artificially limit the amount of memory (and it is written
190  	 * to work with multiple memory ranges).
191  	 */
192  
193  	mem_limit_func();       /* check for "mem=" argument */
194  
195  	mem_max = 0;
196  	for (i = 0; i < npmem_ranges; i++) {
197  		unsigned long rsize;
198  
199  		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
200  		if ((mem_max + rsize) > mem_limit) {
201  			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
202  			if (mem_max == mem_limit)
203  				npmem_ranges = i;
204  			else {
205  				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
206  						       - (mem_max >> PAGE_SHIFT);
207  				npmem_ranges = i + 1;
208  				mem_max = mem_limit;
209  			}
210  			break;
211  		}
212  		mem_max += rsize;
213  	}
214  
215  	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
216  
217  #ifndef CONFIG_SPARSEMEM
218  	/* Merge the ranges, keeping track of the holes */
219  	{
220  		unsigned long end_pfn;
221  		unsigned long hole_pages;
222  
223  		npmem_holes = 0;
224  		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
225  		for (i = 1; i < npmem_ranges; i++) {
226  
227  			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
228  			if (hole_pages) {
229  				pmem_holes[npmem_holes].start_pfn = end_pfn;
230  				pmem_holes[npmem_holes++].pages = hole_pages;
231  				end_pfn += hole_pages;
232  			}
233  			end_pfn += pmem_ranges[i].pages;
234  		}
235  
236  		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
237  		npmem_ranges = 1;
238  	}
239  #endif
240  
241  	/*
242  	 * Initialize and free the full range of memory in each range.
243  	 */
244  
245  	max_pfn = 0;
246  	for (i = 0; i < npmem_ranges; i++) {
247  		unsigned long start_pfn;
248  		unsigned long npages;
249  		unsigned long start;
250  		unsigned long size;
251  
252  		start_pfn = pmem_ranges[i].start_pfn;
253  		npages = pmem_ranges[i].pages;
254  
255  		start = start_pfn << PAGE_SHIFT;
256  		size = npages << PAGE_SHIFT;
257  
258  		/* add system RAM memblock */
259  		memblock_add(start, size);
260  
261  		if ((start_pfn + npages) > max_pfn)
262  			max_pfn = start_pfn + npages;
263  	}
264  
265  	/*
266  	 * We can't use memblock top-down allocations because we only
267  	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
268  	 * the assembly bootup code.
269  	 */
270  	memblock_set_bottom_up(true);
271  
272  	/* IOMMU is always used to access "high mem" on those boxes
273  	 * that can support enough mem that a PCI device couldn't
274  	 * directly DMA to any physical addresses.
275  	 * ISA DMA support will need to revisit this.
276  	 */
277  	max_low_pfn = max_pfn;
278  
279  	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
280  
281  #define PDC_CONSOLE_IO_IODC_SIZE 32768
282  
283  	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
284  				PDC_CONSOLE_IO_IODC_SIZE));
285  	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
286  			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
287  
288  #ifndef CONFIG_SPARSEMEM
289  
290  	/* reserve the holes */
291  
292  	for (i = 0; i < npmem_holes; i++) {
293  		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
294  				(pmem_holes[i].pages << PAGE_SHIFT));
295  	}
296  #endif
297  
298  #ifdef CONFIG_BLK_DEV_INITRD
299  	if (initrd_start) {
300  		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
301  		if (__pa(initrd_start) < mem_max) {
302  			unsigned long initrd_reserve;
303  
304  			if (__pa(initrd_end) > mem_max) {
305  				initrd_reserve = mem_max - __pa(initrd_start);
306  			} else {
307  				initrd_reserve = initrd_end - initrd_start;
308  			}
309  			initrd_below_start_ok = 1;
310  			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
311  
312  			memblock_reserve(__pa(initrd_start), initrd_reserve);
313  		}
314  	}
315  #endif
316  
317  	data_resource.start =  virt_to_phys(&data_start);
318  	data_resource.end = virt_to_phys(_end) - 1;
319  	code_resource.start = virt_to_phys(_text);
320  	code_resource.end = virt_to_phys(&data_start)-1;
321  
322  	/* We don't know which region the kernel will be in, so try
323  	 * all of them.
324  	 */
325  	for (i = 0; i < sysram_resource_count; i++) {
326  		struct resource *res = &sysram_resources[i];
327  		request_resource(res, &code_resource);
328  		request_resource(res, &data_resource);
329  	}
330  	request_resource(&sysram_resources[0], &pdcdata_resource);
331  
332  	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
333  	pdc_pdt_init();
334  
335  	memblock_allow_resize();
336  	memblock_dump_all();
337  }
338  
339  static bool kernel_set_to_readonly;
340  
map_pages(unsigned long start_vaddr,unsigned long start_paddr,unsigned long size,pgprot_t pgprot,int force)341  static void __ref map_pages(unsigned long start_vaddr,
342  			    unsigned long start_paddr, unsigned long size,
343  			    pgprot_t pgprot, int force)
344  {
345  	pmd_t *pmd;
346  	pte_t *pg_table;
347  	unsigned long end_paddr;
348  	unsigned long start_pmd;
349  	unsigned long start_pte;
350  	unsigned long tmp1;
351  	unsigned long tmp2;
352  	unsigned long address;
353  	unsigned long vaddr;
354  	unsigned long ro_start;
355  	unsigned long ro_end;
356  	unsigned long kernel_start, kernel_end;
357  
358  	ro_start = __pa((unsigned long)_text);
359  	ro_end   = __pa((unsigned long)&data_start);
360  	kernel_start = __pa((unsigned long)&__init_begin);
361  	kernel_end  = __pa((unsigned long)&_end);
362  
363  	end_paddr = start_paddr + size;
364  
365  	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
366  	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
367  	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
368  
369  	address = start_paddr;
370  	vaddr = start_vaddr;
371  	while (address < end_paddr) {
372  		pgd_t *pgd = pgd_offset_k(vaddr);
373  		p4d_t *p4d = p4d_offset(pgd, vaddr);
374  		pud_t *pud = pud_offset(p4d, vaddr);
375  
376  #if CONFIG_PGTABLE_LEVELS == 3
377  		if (pud_none(*pud)) {
378  			pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
379  					     PAGE_SIZE << PMD_TABLE_ORDER);
380  			if (!pmd)
381  				panic("pmd allocation failed.\n");
382  			pud_populate(NULL, pud, pmd);
383  		}
384  #endif
385  
386  		pmd = pmd_offset(pud, vaddr);
387  		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
388  			if (pmd_none(*pmd)) {
389  				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
390  				if (!pg_table)
391  					panic("page table allocation failed\n");
392  				pmd_populate_kernel(NULL, pmd, pg_table);
393  			}
394  
395  			pg_table = pte_offset_kernel(pmd, vaddr);
396  			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
397  				pte_t pte;
398  				pgprot_t prot;
399  				bool huge = false;
400  
401  				if (force) {
402  					prot = pgprot;
403  				} else if (address < kernel_start || address >= kernel_end) {
404  					/* outside kernel memory */
405  					prot = PAGE_KERNEL;
406  				} else if (!kernel_set_to_readonly) {
407  					/* still initializing, allow writing to RO memory */
408  					prot = PAGE_KERNEL_RWX;
409  					huge = true;
410  				} else if (address >= ro_start) {
411  					/* Code (ro) and Data areas */
412  					prot = (address < ro_end) ?
413  						PAGE_KERNEL_EXEC : PAGE_KERNEL;
414  					huge = true;
415  				} else {
416  					prot = PAGE_KERNEL;
417  				}
418  
419  				pte = __mk_pte(address, prot);
420  				if (huge)
421  					pte = pte_mkhuge(pte);
422  
423  				if (address >= end_paddr)
424  					break;
425  
426  				set_pte(pg_table, pte);
427  
428  				address += PAGE_SIZE;
429  				vaddr += PAGE_SIZE;
430  			}
431  			start_pte = 0;
432  
433  			if (address >= end_paddr)
434  			    break;
435  		}
436  		start_pmd = 0;
437  	}
438  }
439  
set_kernel_text_rw(int enable_read_write)440  void __init set_kernel_text_rw(int enable_read_write)
441  {
442  	unsigned long start = (unsigned long) __init_begin;
443  	unsigned long end   = (unsigned long) &data_start;
444  
445  	map_pages(start, __pa(start), end-start,
446  		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
447  
448  	/* force the kernel to see the new page table entries */
449  	flush_cache_all();
450  	flush_tlb_all();
451  }
452  
free_initmem(void)453  void free_initmem(void)
454  {
455  	unsigned long init_begin = (unsigned long)__init_begin;
456  	unsigned long init_end = (unsigned long)__init_end;
457  	unsigned long kernel_end  = (unsigned long)&_end;
458  
459  	/* Remap kernel text and data, but do not touch init section yet. */
460  	kernel_set_to_readonly = true;
461  	map_pages(init_end, __pa(init_end), kernel_end - init_end,
462  		  PAGE_KERNEL, 0);
463  
464  	/* The init text pages are marked R-X.  We have to
465  	 * flush the icache and mark them RW-
466  	 *
467  	 * Do a dummy remap of the data section first (the data
468  	 * section is already PAGE_KERNEL) to pull in the TLB entries
469  	 * for map_kernel */
470  	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
471  		  PAGE_KERNEL_RWX, 1);
472  	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
473  	 * map_pages */
474  	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
475  		  PAGE_KERNEL, 1);
476  
477  	/* force the kernel to see the new TLB entries */
478  	__flush_tlb_range(0, init_begin, kernel_end);
479  
480  	/* finally dump all the instructions which were cached, since the
481  	 * pages are no-longer executable */
482  	flush_icache_range(init_begin, init_end);
483  
484  	free_initmem_default(POISON_FREE_INITMEM);
485  
486  	/* set up a new led state on systems shipped LED State panel */
487  	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
488  }
489  
490  
491  #ifdef CONFIG_STRICT_KERNEL_RWX
mark_rodata_ro(void)492  void mark_rodata_ro(void)
493  {
494  	/* rodata memory was already mapped with KERNEL_RO access rights by
495             pagetable_init() and map_pages(). No need to do additional stuff here */
496  	unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
497  
498  	pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
499  }
500  #endif
501  
502  
503  /*
504   * Just an arbitrary offset to serve as a "hole" between mapping areas
505   * (between top of physical memory and a potential pcxl dma mapping
506   * area, and below the vmalloc mapping area).
507   *
508   * The current 32K value just means that there will be a 32K "hole"
509   * between mapping areas. That means that  any out-of-bounds memory
510   * accesses will hopefully be caught. The vmalloc() routines leaves
511   * a hole of 4kB between each vmalloced area for the same reason.
512   */
513  
514   /* Leave room for gateway page expansion */
515  #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
516  #error KERNEL_MAP_START is in gateway reserved region
517  #endif
518  #define MAP_START (KERNEL_MAP_START)
519  
520  #define VM_MAP_OFFSET  (32*1024)
521  #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
522  				     & ~(VM_MAP_OFFSET-1)))
523  
524  void *parisc_vmalloc_start __ro_after_init;
525  EXPORT_SYMBOL(parisc_vmalloc_start);
526  
mem_init(void)527  void __init mem_init(void)
528  {
529  	/* Do sanity checks on IPC (compat) structures */
530  	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
531  #ifndef CONFIG_64BIT
532  	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
533  	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
534  	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
535  #endif
536  #ifdef CONFIG_COMPAT
537  	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
538  	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
539  	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
540  	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
541  #endif
542  
543  	/* Do sanity checks on page table constants */
544  	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
545  	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
546  	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
547  	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
548  			> BITS_PER_LONG);
549  #if CONFIG_PGTABLE_LEVELS == 3
550  	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
551  #else
552  	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
553  #endif
554  
555  #ifdef CONFIG_64BIT
556  	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
557  	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
558  	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
559  #endif
560  
561  	high_memory = __va((max_pfn << PAGE_SHIFT));
562  	set_max_mapnr(max_low_pfn);
563  	memblock_free_all();
564  
565  #ifdef CONFIG_PA11
566  	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
567  		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
568  		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
569  						+ PCXL_DMA_MAP_SIZE);
570  	} else
571  #endif
572  		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
573  
574  #if 0
575  	/*
576  	 * Do not expose the virtual kernel memory layout to userspace.
577  	 * But keep code for debugging purposes.
578  	 */
579  	printk("virtual kernel memory layout:\n"
580  	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
581  	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
582  	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
583  	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
584  	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
585  	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
586  
587  	       (void*)VMALLOC_START, (void*)VMALLOC_END,
588  	       (VMALLOC_END - VMALLOC_START) >> 20,
589  
590  	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
591  	       (unsigned long)(FIXMAP_SIZE / 1024),
592  
593  	       __va(0), high_memory,
594  	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
595  
596  	       __init_begin, __init_end,
597  	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
598  
599  	       _etext, _edata,
600  	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
601  
602  	       _text, _etext,
603  	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
604  #endif
605  }
606  
607  unsigned long *empty_zero_page __ro_after_init;
608  EXPORT_SYMBOL(empty_zero_page);
609  
610  /*
611   * pagetable_init() sets up the page tables
612   *
613   * Note that gateway_init() places the Linux gateway page at page 0.
614   * Since gateway pages cannot be dereferenced this has the desirable
615   * side effect of trapping those pesky NULL-reference errors in the
616   * kernel.
617   */
pagetable_init(void)618  static void __init pagetable_init(void)
619  {
620  	int range;
621  
622  	/* Map each physical memory range to its kernel vaddr */
623  
624  	for (range = 0; range < npmem_ranges; range++) {
625  		unsigned long start_paddr;
626  		unsigned long size;
627  
628  		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
629  		size = pmem_ranges[range].pages << PAGE_SHIFT;
630  
631  		map_pages((unsigned long)__va(start_paddr), start_paddr,
632  			  size, PAGE_KERNEL, 0);
633  	}
634  
635  #ifdef CONFIG_BLK_DEV_INITRD
636  	if (initrd_end && initrd_end > mem_limit) {
637  		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
638  		map_pages(initrd_start, __pa(initrd_start),
639  			  initrd_end - initrd_start, PAGE_KERNEL, 0);
640  	}
641  #endif
642  
643  	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
644  	if (!empty_zero_page)
645  		panic("zero page allocation failed.\n");
646  
647  }
648  
gateway_init(void)649  static void __init gateway_init(void)
650  {
651  	unsigned long linux_gateway_page_addr;
652  	/* FIXME: This is 'const' in order to trick the compiler
653  	   into not treating it as DP-relative data. */
654  	extern void * const linux_gateway_page;
655  
656  	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
657  
658  	/*
659  	 * Setup Linux Gateway page.
660  	 *
661  	 * The Linux gateway page will reside in kernel space (on virtual
662  	 * page 0), so it doesn't need to be aliased into user space.
663  	 */
664  
665  	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
666  		  PAGE_SIZE, PAGE_GATEWAY, 1);
667  }
668  
fixmap_init(void)669  static void __init fixmap_init(void)
670  {
671  	unsigned long addr = FIXMAP_START;
672  	unsigned long end = FIXMAP_START + FIXMAP_SIZE;
673  	pgd_t *pgd = pgd_offset_k(addr);
674  	p4d_t *p4d = p4d_offset(pgd, addr);
675  	pud_t *pud = pud_offset(p4d, addr);
676  	pmd_t *pmd;
677  
678  	BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
679  
680  #if CONFIG_PGTABLE_LEVELS == 3
681  	if (pud_none(*pud)) {
682  		pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
683  				     PAGE_SIZE << PMD_TABLE_ORDER);
684  		if (!pmd)
685  			panic("fixmap: pmd allocation failed.\n");
686  		pud_populate(NULL, pud, pmd);
687  	}
688  #endif
689  
690  	pmd = pmd_offset(pud, addr);
691  	do {
692  		pte_t *pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
693  		if (!pte)
694  			panic("fixmap: pte allocation failed.\n");
695  
696  		pmd_populate_kernel(&init_mm, pmd, pte);
697  
698  		addr += PAGE_SIZE;
699  	} while (addr < end);
700  }
701  
parisc_bootmem_free(void)702  static void __init parisc_bootmem_free(void)
703  {
704  	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
705  
706  	max_zone_pfn[0] = memblock_end_of_DRAM();
707  
708  	free_area_init(max_zone_pfn);
709  }
710  
paging_init(void)711  void __init paging_init(void)
712  {
713  	setup_bootmem();
714  	pagetable_init();
715  	gateway_init();
716  	fixmap_init();
717  	flush_cache_all_local(); /* start with known state */
718  	flush_tlb_all_local(NULL);
719  
720  	sparse_init();
721  	parisc_bootmem_free();
722  }
723  
alloc_btlb(unsigned long start,unsigned long end,int * slot,unsigned long entry_info)724  static void alloc_btlb(unsigned long start, unsigned long end, int *slot,
725  			unsigned long entry_info)
726  {
727  	const int slot_max = btlb_info.fixed_range_info.num_comb;
728  	int min_num_pages = btlb_info.min_size;
729  	unsigned long size;
730  
731  	/* map at minimum 4 pages */
732  	if (min_num_pages < 4)
733  		min_num_pages = 4;
734  
735  	size = HUGEPAGE_SIZE;
736  	while (start < end && *slot < slot_max && size >= PAGE_SIZE) {
737  		/* starting address must have same alignment as size! */
738  		/* if correctly aligned and fits in double size, increase */
739  		if (((start & (2 * size - 1)) == 0) &&
740  		    (end - start) >= (2 * size)) {
741  			size <<= 1;
742  			continue;
743  		}
744  		/* if current size alignment is too big, try smaller size */
745  		if ((start & (size - 1)) != 0) {
746  			size >>= 1;
747  			continue;
748  		}
749  		if ((end - start) >= size) {
750  			if ((size >> PAGE_SHIFT) >= min_num_pages)
751  				pdc_btlb_insert(start >> PAGE_SHIFT, __pa(start) >> PAGE_SHIFT,
752  					size >> PAGE_SHIFT, entry_info, *slot);
753  			(*slot)++;
754  			start += size;
755  			continue;
756  		}
757  		size /= 2;
758  		continue;
759  	}
760  }
761  
btlb_init_per_cpu(void)762  void btlb_init_per_cpu(void)
763  {
764  	unsigned long s, t, e;
765  	int slot;
766  
767  	/* BTLBs are not available on 64-bit CPUs */
768  	if (IS_ENABLED(CONFIG_PA20))
769  		return;
770  	else if (pdc_btlb_info(&btlb_info) < 0) {
771  		memset(&btlb_info, 0, sizeof btlb_info);
772  	}
773  
774  	/* insert BLTLBs for code and data segments */
775  	s = (uintptr_t) dereference_function_descriptor(&_stext);
776  	e = (uintptr_t) dereference_function_descriptor(&_etext);
777  	t = (uintptr_t) dereference_function_descriptor(&_sdata);
778  	BUG_ON(t != e);
779  
780  	/* code segments */
781  	slot = 0;
782  	alloc_btlb(s, e, &slot, 0x13800000);
783  
784  	/* sanity check */
785  	t = (uintptr_t) dereference_function_descriptor(&_edata);
786  	e = (uintptr_t) dereference_function_descriptor(&__bss_start);
787  	BUG_ON(t != e);
788  
789  	/* data segments */
790  	s = (uintptr_t) dereference_function_descriptor(&_sdata);
791  	e = (uintptr_t) dereference_function_descriptor(&__bss_stop);
792  	alloc_btlb(s, e, &slot, 0x11800000);
793  }
794  
795  #ifdef CONFIG_PA20
796  
797  /*
798   * Currently, all PA20 chips have 18 bit protection IDs, which is the
799   * limiting factor (space ids are 32 bits).
800   */
801  
802  #define NR_SPACE_IDS 262144
803  
804  #else
805  
806  /*
807   * Currently we have a one-to-one relationship between space IDs and
808   * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
809   * support 15 bit protection IDs, so that is the limiting factor.
810   * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
811   * probably not worth the effort for a special case here.
812   */
813  
814  #define NR_SPACE_IDS 32768
815  
816  #endif  /* !CONFIG_PA20 */
817  
818  #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
819  #define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
820  
821  static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
822  static unsigned long dirty_space_id[SID_ARRAY_SIZE];
823  static unsigned long space_id_index;
824  static unsigned long free_space_ids = NR_SPACE_IDS - 1;
825  static unsigned long dirty_space_ids;
826  
827  static DEFINE_SPINLOCK(sid_lock);
828  
alloc_sid(void)829  unsigned long alloc_sid(void)
830  {
831  	unsigned long index;
832  
833  	spin_lock(&sid_lock);
834  
835  	if (free_space_ids == 0) {
836  		if (dirty_space_ids != 0) {
837  			spin_unlock(&sid_lock);
838  			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
839  			spin_lock(&sid_lock);
840  		}
841  		BUG_ON(free_space_ids == 0);
842  	}
843  
844  	free_space_ids--;
845  
846  	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
847  	space_id[BIT_WORD(index)] |= BIT_MASK(index);
848  	space_id_index = index;
849  
850  	spin_unlock(&sid_lock);
851  
852  	return index << SPACEID_SHIFT;
853  }
854  
free_sid(unsigned long spaceid)855  void free_sid(unsigned long spaceid)
856  {
857  	unsigned long index = spaceid >> SPACEID_SHIFT;
858  	unsigned long *dirty_space_offset, mask;
859  
860  	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
861  	mask = BIT_MASK(index);
862  
863  	spin_lock(&sid_lock);
864  
865  	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
866  
867  	*dirty_space_offset |= mask;
868  	dirty_space_ids++;
869  
870  	spin_unlock(&sid_lock);
871  }
872  
873  
874  #ifdef CONFIG_SMP
get_dirty_sids(unsigned long * ndirtyptr,unsigned long * dirty_array)875  static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
876  {
877  	int i;
878  
879  	/* NOTE: sid_lock must be held upon entry */
880  
881  	*ndirtyptr = dirty_space_ids;
882  	if (dirty_space_ids != 0) {
883  	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
884  		dirty_array[i] = dirty_space_id[i];
885  		dirty_space_id[i] = 0;
886  	    }
887  	    dirty_space_ids = 0;
888  	}
889  
890  	return;
891  }
892  
recycle_sids(unsigned long ndirty,unsigned long * dirty_array)893  static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
894  {
895  	int i;
896  
897  	/* NOTE: sid_lock must be held upon entry */
898  
899  	if (ndirty != 0) {
900  		for (i = 0; i < SID_ARRAY_SIZE; i++) {
901  			space_id[i] ^= dirty_array[i];
902  		}
903  
904  		free_space_ids += ndirty;
905  		space_id_index = 0;
906  	}
907  }
908  
909  #else /* CONFIG_SMP */
910  
recycle_sids(void)911  static void recycle_sids(void)
912  {
913  	int i;
914  
915  	/* NOTE: sid_lock must be held upon entry */
916  
917  	if (dirty_space_ids != 0) {
918  		for (i = 0; i < SID_ARRAY_SIZE; i++) {
919  			space_id[i] ^= dirty_space_id[i];
920  			dirty_space_id[i] = 0;
921  		}
922  
923  		free_space_ids += dirty_space_ids;
924  		dirty_space_ids = 0;
925  		space_id_index = 0;
926  	}
927  }
928  #endif
929  
930  /*
931   * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
932   * purged, we can safely reuse the space ids that were released but
933   * not flushed from the tlb.
934   */
935  
936  #ifdef CONFIG_SMP
937  
938  static unsigned long recycle_ndirty;
939  static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
940  static unsigned int recycle_inuse;
941  
flush_tlb_all(void)942  void flush_tlb_all(void)
943  {
944  	int do_recycle;
945  
946  	do_recycle = 0;
947  	spin_lock(&sid_lock);
948  	__inc_irq_stat(irq_tlb_count);
949  	if (dirty_space_ids > RECYCLE_THRESHOLD) {
950  	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
951  	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
952  	    recycle_inuse++;
953  	    do_recycle++;
954  	}
955  	spin_unlock(&sid_lock);
956  	on_each_cpu(flush_tlb_all_local, NULL, 1);
957  	if (do_recycle) {
958  	    spin_lock(&sid_lock);
959  	    recycle_sids(recycle_ndirty,recycle_dirty_array);
960  	    recycle_inuse = 0;
961  	    spin_unlock(&sid_lock);
962  	}
963  }
964  #else
flush_tlb_all(void)965  void flush_tlb_all(void)
966  {
967  	spin_lock(&sid_lock);
968  	__inc_irq_stat(irq_tlb_count);
969  	flush_tlb_all_local(NULL);
970  	recycle_sids();
971  	spin_unlock(&sid_lock);
972  }
973  #endif
974  
975  static const pgprot_t protection_map[16] = {
976  	[VM_NONE]					= PAGE_NONE,
977  	[VM_READ]					= PAGE_READONLY,
978  	[VM_WRITE]					= PAGE_NONE,
979  	[VM_WRITE | VM_READ]				= PAGE_READONLY,
980  	[VM_EXEC]					= PAGE_EXECREAD,
981  	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
982  	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
983  	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
984  	[VM_SHARED]					= PAGE_NONE,
985  	[VM_SHARED | VM_READ]				= PAGE_READONLY,
986  	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
987  	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
988  	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
989  	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
990  	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
991  	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
992  };
993  DECLARE_VM_GET_PAGE_PROT
994