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
38extern int  data_start;
39extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
40
41#if CONFIG_PGTABLE_LEVELS == 3
42pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
43#endif
44
45pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
46pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
47
48static struct resource data_resource = {
49	.name	= "Kernel data",
50	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
51};
52
53static struct resource code_resource = {
54	.name	= "Kernel code",
55	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
56};
57
58static struct resource pdcdata_resource = {
59	.name	= "PDC data (Page Zero)",
60	.start	= 0,
61	.end	= 0x9ff,
62	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
63};
64
65static 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
71physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
72int 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
80static unsigned long mem_limit __read_mostly = MAX_MEM;
81
82static 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
111static 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
340static bool kernel_set_to_readonly;
341
342static 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
441void __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
454void 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
493void 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
525void *parisc_vmalloc_start __ro_after_init;
526EXPORT_SYMBOL(parisc_vmalloc_start);
527
528void __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
608unsigned long *empty_zero_page __ro_after_init;
609EXPORT_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 */
619static 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
650static 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
670static 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
703static 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
712void __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
725static 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
763void 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
822static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
823static unsigned long dirty_space_id[SID_ARRAY_SIZE];
824static unsigned long space_id_index;
825static unsigned long free_space_ids = NR_SPACE_IDS - 1;
826static unsigned long dirty_space_ids;
827
828static DEFINE_SPINLOCK(sid_lock);
829
830unsigned 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
856void 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
876static 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
894static 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
912static 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
939static unsigned long recycle_ndirty;
940static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
941static unsigned int recycle_inuse;
942
943void 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
966void 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
976static 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};
994DECLARE_VM_GET_PAGE_PROT
995