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v6.13.7
   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#include <linux/execmem.h>
  28
  29#include <asm/pgalloc.h>
  30#include <asm/tlb.h>
  31#include <asm/pdc_chassis.h>
  32#include <asm/mmzone.h>
  33#include <asm/sections.h>
  34#include <asm/msgbuf.h>
  35#include <asm/sparsemem.h>
  36#include <asm/asm-offsets.h>
  37#include <asm/shmbuf.h>
  38
  39extern int  data_start;
  40extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
  41
  42#if CONFIG_PGTABLE_LEVELS == 3
  43pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
  44#endif
  45
  46pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
  47pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
  48
  49static struct resource data_resource = {
  50	.name	= "Kernel data",
  51	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
  52};
  53
  54static struct resource code_resource = {
  55	.name	= "Kernel code",
  56	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
  57};
  58
  59static struct resource pdcdata_resource = {
  60	.name	= "PDC data (Page Zero)",
  61	.start	= 0,
  62	.end	= 0x9ff,
  63	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
  64};
  65
  66static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
  67
  68/* The following array is initialized from the firmware specific
  69 * information retrieved in kernel/inventory.c.
  70 */
  71
  72physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
  73int npmem_ranges __initdata;
  74
  75#ifdef CONFIG_64BIT
  76#define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
  77#else /* !CONFIG_64BIT */
  78#define MAX_MEM         (3584U*1024U*1024U)
  79#endif /* !CONFIG_64BIT */
  80
  81static unsigned long mem_limit __read_mostly = MAX_MEM;
  82
  83static void __init mem_limit_func(void)
  84{
  85	char *cp, *end;
  86	unsigned long limit;
  87
  88	/* We need this before __setup() functions are called */
  89
  90	limit = MAX_MEM;
  91	for (cp = boot_command_line; *cp; ) {
  92		if (memcmp(cp, "mem=", 4) == 0) {
  93			cp += 4;
  94			limit = memparse(cp, &end);
  95			if (end != cp)
  96				break;
  97			cp = end;
  98		} else {
  99			while (*cp != ' ' && *cp)
 100				++cp;
 101			while (*cp == ' ')
 102				++cp;
 103		}
 104	}
 105
 106	if (limit < mem_limit)
 107		mem_limit = limit;
 108}
 109
 110#define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
 111
 112static void __init setup_bootmem(void)
 113{
 114	unsigned long mem_max;
 115#ifndef CONFIG_SPARSEMEM
 116	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
 117	int npmem_holes;
 118#endif
 119	int i, sysram_resource_count;
 120
 121	disable_sr_hashing(); /* Turn off space register hashing */
 122
 123	/*
 124	 * Sort the ranges. Since the number of ranges is typically
 125	 * small, and performance is not an issue here, just do
 126	 * a simple insertion sort.
 127	 */
 128
 129	for (i = 1; i < npmem_ranges; i++) {
 130		int j;
 131
 132		for (j = i; j > 0; j--) {
 133			if (pmem_ranges[j-1].start_pfn <
 134			    pmem_ranges[j].start_pfn) {
 135
 136				break;
 137			}
 138			swap(pmem_ranges[j-1], pmem_ranges[j]);
 139		}
 140	}
 141
 142#ifndef CONFIG_SPARSEMEM
 143	/*
 144	 * Throw out ranges that are too far apart (controlled by
 145	 * MAX_GAP).
 146	 */
 147
 148	for (i = 1; i < npmem_ranges; i++) {
 149		if (pmem_ranges[i].start_pfn -
 150			(pmem_ranges[i-1].start_pfn +
 151			 pmem_ranges[i-1].pages) > MAX_GAP) {
 152			npmem_ranges = i;
 153			printk("Large gap in memory detected (%ld pages). "
 154			       "Consider turning on CONFIG_SPARSEMEM\n",
 155			       pmem_ranges[i].start_pfn -
 156			       (pmem_ranges[i-1].start_pfn +
 157			        pmem_ranges[i-1].pages));
 158			break;
 159		}
 160	}
 161#endif
 162
 163	/* Print the memory ranges */
 164	pr_info("Memory Ranges:\n");
 165
 166	for (i = 0; i < npmem_ranges; i++) {
 167		struct resource *res = &sysram_resources[i];
 168		unsigned long start;
 169		unsigned long size;
 170
 171		size = (pmem_ranges[i].pages << PAGE_SHIFT);
 172		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
 173		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
 174			i, start, start + (size - 1), size >> 20);
 175
 176		/* request memory resource */
 177		res->name = "System RAM";
 178		res->start = start;
 179		res->end = start + size - 1;
 180		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 181		request_resource(&iomem_resource, res);
 182	}
 183
 184	sysram_resource_count = npmem_ranges;
 185
 186	/*
 187	 * For 32 bit kernels we limit the amount of memory we can
 188	 * support, in order to preserve enough kernel address space
 189	 * for other purposes. For 64 bit kernels we don't normally
 190	 * limit the memory, but this mechanism can be used to
 191	 * artificially limit the amount of memory (and it is written
 192	 * to work with multiple memory ranges).
 193	 */
 194
 195	mem_limit_func();       /* check for "mem=" argument */
 196
 197	mem_max = 0;
 198	for (i = 0; i < npmem_ranges; i++) {
 199		unsigned long rsize;
 200
 201		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
 202		if ((mem_max + rsize) > mem_limit) {
 203			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
 204			if (mem_max == mem_limit)
 205				npmem_ranges = i;
 206			else {
 207				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
 208						       - (mem_max >> PAGE_SHIFT);
 209				npmem_ranges = i + 1;
 210				mem_max = mem_limit;
 211			}
 212			break;
 213		}
 214		mem_max += rsize;
 215	}
 216
 217	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
 218
 219#ifndef CONFIG_SPARSEMEM
 220	/* Merge the ranges, keeping track of the holes */
 221	{
 222		unsigned long end_pfn;
 223		unsigned long hole_pages;
 224
 225		npmem_holes = 0;
 226		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
 227		for (i = 1; i < npmem_ranges; i++) {
 228
 229			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
 230			if (hole_pages) {
 231				pmem_holes[npmem_holes].start_pfn = end_pfn;
 232				pmem_holes[npmem_holes++].pages = hole_pages;
 233				end_pfn += hole_pages;
 234			}
 235			end_pfn += pmem_ranges[i].pages;
 236		}
 237
 238		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
 239		npmem_ranges = 1;
 240	}
 241#endif
 242
 243	/*
 244	 * Initialize and free the full range of memory in each range.
 245	 */
 246
 247	max_pfn = 0;
 248	for (i = 0; i < npmem_ranges; i++) {
 249		unsigned long start_pfn;
 250		unsigned long npages;
 251		unsigned long start;
 252		unsigned long size;
 253
 254		start_pfn = pmem_ranges[i].start_pfn;
 255		npages = pmem_ranges[i].pages;
 256
 257		start = start_pfn << PAGE_SHIFT;
 258		size = npages << PAGE_SHIFT;
 259
 260		/* add system RAM memblock */
 261		memblock_add(start, size);
 262
 263		if ((start_pfn + npages) > max_pfn)
 264			max_pfn = start_pfn + npages;
 265	}
 266
 267	/*
 268	 * We can't use memblock top-down allocations because we only
 269	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
 270	 * the assembly bootup code.
 271	 */
 272	memblock_set_bottom_up(true);
 273
 274	/* IOMMU is always used to access "high mem" on those boxes
 275	 * that can support enough mem that a PCI device couldn't
 276	 * directly DMA to any physical addresses.
 277	 * ISA DMA support will need to revisit this.
 278	 */
 279	max_low_pfn = max_pfn;
 280
 281	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
 282
 283#define PDC_CONSOLE_IO_IODC_SIZE 32768
 284
 285	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
 286				PDC_CONSOLE_IO_IODC_SIZE));
 287	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
 288			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
 289
 290#ifndef CONFIG_SPARSEMEM
 291
 292	/* reserve the holes */
 293
 294	for (i = 0; i < npmem_holes; i++) {
 295		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
 296				(pmem_holes[i].pages << PAGE_SHIFT));
 297	}
 298#endif
 299
 300#ifdef CONFIG_BLK_DEV_INITRD
 301	if (initrd_start) {
 302		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
 303		if (__pa(initrd_start) < mem_max) {
 304			unsigned long initrd_reserve;
 305
 306			if (__pa(initrd_end) > mem_max) {
 307				initrd_reserve = mem_max - __pa(initrd_start);
 308			} else {
 309				initrd_reserve = initrd_end - initrd_start;
 310			}
 311			initrd_below_start_ok = 1;
 312			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
 313
 314			memblock_reserve(__pa(initrd_start), initrd_reserve);
 315		}
 316	}
 317#endif
 318
 319	data_resource.start =  virt_to_phys(&data_start);
 320	data_resource.end = virt_to_phys(_end) - 1;
 321	code_resource.start = virt_to_phys(_text);
 322	code_resource.end = virt_to_phys(&data_start)-1;
 323
 324	/* We don't know which region the kernel will be in, so try
 325	 * all of them.
 326	 */
 327	for (i = 0; i < sysram_resource_count; i++) {
 328		struct resource *res = &sysram_resources[i];
 329		request_resource(res, &code_resource);
 330		request_resource(res, &data_resource);
 331	}
 332	request_resource(&sysram_resources[0], &pdcdata_resource);
 333
 334	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
 335	pdc_pdt_init();
 336
 337	memblock_allow_resize();
 338	memblock_dump_all();
 339}
 340
 341static bool kernel_set_to_readonly;
 342
 343static void __ref map_pages(unsigned long start_vaddr,
 344			    unsigned long start_paddr, unsigned long size,
 345			    pgprot_t pgprot, int force)
 346{
 347	pmd_t *pmd;
 348	pte_t *pg_table;
 349	unsigned long end_paddr;
 350	unsigned long start_pmd;
 351	unsigned long start_pte;
 352	unsigned long tmp1;
 353	unsigned long tmp2;
 354	unsigned long address;
 355	unsigned long vaddr;
 356	unsigned long ro_start;
 357	unsigned long ro_end;
 358	unsigned long kernel_start, kernel_end;
 359
 360	ro_start = __pa((unsigned long)_text);
 361	ro_end   = __pa((unsigned long)&data_start);
 362	kernel_start = __pa((unsigned long)&__init_begin);
 363	kernel_end  = __pa((unsigned long)&_end);
 364
 365	end_paddr = start_paddr + size;
 366
 367	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
 368	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
 369	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
 370
 371	address = start_paddr;
 372	vaddr = start_vaddr;
 373	while (address < end_paddr) {
 374		pgd_t *pgd = pgd_offset_k(vaddr);
 375		p4d_t *p4d = p4d_offset(pgd, vaddr);
 376		pud_t *pud = pud_offset(p4d, vaddr);
 377
 378#if CONFIG_PGTABLE_LEVELS == 3
 379		if (pud_none(*pud)) {
 380			pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
 381					     PAGE_SIZE << PMD_TABLE_ORDER);
 382			if (!pmd)
 383				panic("pmd allocation failed.\n");
 384			pud_populate(NULL, pud, pmd);
 385		}
 386#endif
 387
 388		pmd = pmd_offset(pud, vaddr);
 389		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
 390			if (pmd_none(*pmd)) {
 391				pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 392				if (!pg_table)
 393					panic("page table allocation failed\n");
 394				pmd_populate_kernel(NULL, pmd, pg_table);
 395			}
 396
 397			pg_table = pte_offset_kernel(pmd, vaddr);
 398			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
 399				pte_t pte;
 400				pgprot_t prot;
 401				bool huge = false;
 402
 403				if (force) {
 404					prot = pgprot;
 405				} else if (address < kernel_start || address >= kernel_end) {
 406					/* outside kernel memory */
 407					prot = PAGE_KERNEL;
 408				} else if (!kernel_set_to_readonly) {
 409					/* still initializing, allow writing to RO memory */
 410					prot = PAGE_KERNEL_RWX;
 411					huge = true;
 412				} else if (address >= ro_start) {
 413					/* Code (ro) and Data areas */
 414					prot = (address < ro_end) ?
 415						PAGE_KERNEL_EXEC : PAGE_KERNEL;
 416					huge = true;
 417				} else {
 418					prot = PAGE_KERNEL;
 419				}
 420
 421				pte = __mk_pte(address, prot);
 422				if (huge)
 423					pte = pte_mkhuge(pte);
 424
 425				if (address >= end_paddr)
 426					break;
 427
 428				set_pte(pg_table, pte);
 429
 430				address += PAGE_SIZE;
 431				vaddr += PAGE_SIZE;
 432			}
 433			start_pte = 0;
 434
 435			if (address >= end_paddr)
 436			    break;
 437		}
 438		start_pmd = 0;
 439	}
 440}
 441
 442void __init set_kernel_text_rw(int enable_read_write)
 443{
 444	unsigned long start = (unsigned long) __init_begin;
 445	unsigned long end   = (unsigned long) &data_start;
 446
 447	map_pages(start, __pa(start), end-start,
 448		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
 449
 450	/* force the kernel to see the new page table entries */
 451	flush_cache_all();
 452	flush_tlb_all();
 453}
 454
 455void free_initmem(void)
 456{
 457	unsigned long init_begin = (unsigned long)__init_begin;
 458	unsigned long init_end = (unsigned long)__init_end;
 459	unsigned long kernel_end  = (unsigned long)&_end;
 460
 461	/* Remap kernel text and data, but do not touch init section yet. */
 
 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	unsigned long start = (unsigned long) &__start_rodata;
 496	unsigned long end = (unsigned long) &__end_rodata;
 497
 498	pr_info("Write protecting the kernel read-only data: %luk\n",
 499	       (end - start) >> 10);
 500
 501	kernel_set_to_readonly = true;
 502	map_pages(start, __pa(start), end - start, PAGE_KERNEL, 0);
 503
 504	/* force the kernel to see the new page table entries */
 505	flush_cache_all();
 506	flush_tlb_all();
 507}
 508#endif
 509
 510
 511/*
 512 * Just an arbitrary offset to serve as a "hole" between mapping areas
 513 * (between top of physical memory and a potential pcxl dma mapping
 514 * area, and below the vmalloc mapping area).
 515 *
 516 * The current 32K value just means that there will be a 32K "hole"
 517 * between mapping areas. That means that  any out-of-bounds memory
 518 * accesses will hopefully be caught. The vmalloc() routines leaves
 519 * a hole of 4kB between each vmalloced area for the same reason.
 520 */
 521
 522 /* Leave room for gateway page expansion */
 523#if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
 524#error KERNEL_MAP_START is in gateway reserved region
 525#endif
 526#define MAP_START (KERNEL_MAP_START)
 527
 528#define VM_MAP_OFFSET  (32*1024)
 529#define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
 530				     & ~(VM_MAP_OFFSET-1)))
 531
 532void *parisc_vmalloc_start __ro_after_init;
 533EXPORT_SYMBOL(parisc_vmalloc_start);
 534
 
 
 
 
 535void __init mem_init(void)
 536{
 537	/* Do sanity checks on IPC (compat) structures */
 538	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
 539#ifndef CONFIG_64BIT
 540	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
 541	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
 542	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
 543#endif
 544#ifdef CONFIG_COMPAT
 545	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
 546	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
 547	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
 548	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
 549#endif
 550
 551	/* Do sanity checks on page table constants */
 552	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
 553	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
 554	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
 555	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
 556			> BITS_PER_LONG);
 557#if CONFIG_PGTABLE_LEVELS == 3
 558	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
 559#else
 560	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
 561#endif
 562
 563#ifdef CONFIG_64BIT
 564	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
 565	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
 566	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
 567#endif
 568
 569	high_memory = __va((max_pfn << PAGE_SHIFT));
 570	set_max_mapnr(max_low_pfn);
 571	memblock_free_all();
 572
 573#ifdef CONFIG_PA11
 574	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
 575		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
 576		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
 577						+ PCXL_DMA_MAP_SIZE);
 578	} else
 579#endif
 580		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
 581
 582#if 0
 583	/*
 584	 * Do not expose the virtual kernel memory layout to userspace.
 585	 * But keep code for debugging purposes.
 586	 */
 587	printk("virtual kernel memory layout:\n"
 588	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
 589	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
 590	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
 591	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
 592	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
 593	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
 594
 595	       (void*)VMALLOC_START, (void*)VMALLOC_END,
 596	       (VMALLOC_END - VMALLOC_START) >> 20,
 597
 598	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
 599	       (unsigned long)(FIXMAP_SIZE / 1024),
 600
 601	       __va(0), high_memory,
 602	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
 603
 604	       __init_begin, __init_end,
 605	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
 606
 607	       _etext, _edata,
 608	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
 609
 610	       _text, _etext,
 611	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
 612#endif
 613}
 614
 615unsigned long *empty_zero_page __ro_after_init;
 616EXPORT_SYMBOL(empty_zero_page);
 617
 618/*
 619 * pagetable_init() sets up the page tables
 620 *
 621 * Note that gateway_init() places the Linux gateway page at page 0.
 622 * Since gateway pages cannot be dereferenced this has the desirable
 623 * side effect of trapping those pesky NULL-reference errors in the
 624 * kernel.
 625 */
 626static void __init pagetable_init(void)
 627{
 628	int range;
 629
 630	/* Map each physical memory range to its kernel vaddr */
 631
 632	for (range = 0; range < npmem_ranges; range++) {
 633		unsigned long start_paddr;
 
 634		unsigned long size;
 635
 636		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
 637		size = pmem_ranges[range].pages << PAGE_SHIFT;
 
 638
 639		map_pages((unsigned long)__va(start_paddr), start_paddr,
 640			  size, PAGE_KERNEL, 0);
 641	}
 642
 643#ifdef CONFIG_BLK_DEV_INITRD
 644	if (initrd_end && initrd_end > mem_limit) {
 645		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
 646		map_pages(initrd_start, __pa(initrd_start),
 647			  initrd_end - initrd_start, PAGE_KERNEL, 0);
 648	}
 649#endif
 650
 651	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 652	if (!empty_zero_page)
 653		panic("zero page allocation failed.\n");
 654
 655}
 656
 657static void __init gateway_init(void)
 658{
 659	unsigned long linux_gateway_page_addr;
 660	/* FIXME: This is 'const' in order to trick the compiler
 661	   into not treating it as DP-relative data. */
 662	extern void * const linux_gateway_page;
 663
 664	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
 665
 666	/*
 667	 * Setup Linux Gateway page.
 668	 *
 669	 * The Linux gateway page will reside in kernel space (on virtual
 670	 * page 0), so it doesn't need to be aliased into user space.
 671	 */
 672
 673	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
 674		  PAGE_SIZE, PAGE_GATEWAY, 1);
 675}
 676
 677static void __init fixmap_init(void)
 678{
 679	unsigned long addr = FIXMAP_START;
 680	unsigned long end = FIXMAP_START + FIXMAP_SIZE;
 681	pgd_t *pgd = pgd_offset_k(addr);
 682	p4d_t *p4d = p4d_offset(pgd, addr);
 683	pud_t *pud = pud_offset(p4d, addr);
 684	pmd_t *pmd;
 685
 686	BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
 687
 688#if CONFIG_PGTABLE_LEVELS == 3
 689	if (pud_none(*pud)) {
 690		pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
 691				     PAGE_SIZE << PMD_TABLE_ORDER);
 692		if (!pmd)
 693			panic("fixmap: pmd allocation failed.\n");
 694		pud_populate(NULL, pud, pmd);
 695	}
 696#endif
 697
 698	pmd = pmd_offset(pud, addr);
 699	do {
 700		pte_t *pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 701		if (!pte)
 702			panic("fixmap: pte allocation failed.\n");
 703
 704		pmd_populate_kernel(&init_mm, pmd, pte);
 705
 706		addr += PAGE_SIZE;
 707	} while (addr < end);
 708}
 709
 710static void __init parisc_bootmem_free(void)
 711{
 712	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
 713
 714	max_zone_pfn[0] = memblock_end_of_DRAM();
 715
 716	free_area_init(max_zone_pfn);
 717}
 718
 719void __init paging_init(void)
 720{
 721	setup_bootmem();
 722	pagetable_init();
 723	gateway_init();
 724	fixmap_init();
 725	flush_cache_all_local(); /* start with known state */
 726	flush_tlb_all_local(NULL);
 727
 728	sparse_init();
 729	parisc_bootmem_free();
 730}
 731
 732static void alloc_btlb(unsigned long start, unsigned long end, int *slot,
 733			unsigned long entry_info)
 734{
 735	const int slot_max = btlb_info.fixed_range_info.num_comb;
 736	int min_num_pages = btlb_info.min_size;
 737	unsigned long size;
 738
 739	/* map at minimum 4 pages */
 740	if (min_num_pages < 4)
 741		min_num_pages = 4;
 742
 743	size = HUGEPAGE_SIZE;
 744	while (start < end && *slot < slot_max && size >= PAGE_SIZE) {
 745		/* starting address must have same alignment as size! */
 746		/* if correctly aligned and fits in double size, increase */
 747		if (((start & (2 * size - 1)) == 0) &&
 748		    (end - start) >= (2 * size)) {
 749			size <<= 1;
 750			continue;
 751		}
 752		/* if current size alignment is too big, try smaller size */
 753		if ((start & (size - 1)) != 0) {
 754			size >>= 1;
 755			continue;
 756		}
 757		if ((end - start) >= size) {
 758			if ((size >> PAGE_SHIFT) >= min_num_pages)
 759				pdc_btlb_insert(start >> PAGE_SHIFT, __pa(start) >> PAGE_SHIFT,
 760					size >> PAGE_SHIFT, entry_info, *slot);
 761			(*slot)++;
 762			start += size;
 763			continue;
 764		}
 765		size /= 2;
 766		continue;
 767	}
 768}
 769
 770void btlb_init_per_cpu(void)
 771{
 772	unsigned long s, t, e;
 773	int slot;
 774
 775	/* BTLBs are not available on 64-bit CPUs */
 776	if (IS_ENABLED(CONFIG_PA20))
 777		return;
 778	else if (pdc_btlb_info(&btlb_info) < 0) {
 779		memset(&btlb_info, 0, sizeof btlb_info);
 780	}
 781
 782	/* insert BLTLBs for code and data segments */
 783	s = (uintptr_t) dereference_function_descriptor(&_stext);
 784	e = (uintptr_t) dereference_function_descriptor(&_etext);
 785	t = (uintptr_t) dereference_function_descriptor(&_sdata);
 786	BUG_ON(t != e);
 787
 788	/* code segments */
 789	slot = 0;
 790	alloc_btlb(s, e, &slot, 0x13800000);
 791
 792	/* sanity check */
 793	t = (uintptr_t) dereference_function_descriptor(&_edata);
 794	e = (uintptr_t) dereference_function_descriptor(&__bss_start);
 795	BUG_ON(t != e);
 796
 797	/* data segments */
 798	s = (uintptr_t) dereference_function_descriptor(&_sdata);
 799	e = (uintptr_t) dereference_function_descriptor(&__bss_stop);
 800	alloc_btlb(s, e, &slot, 0x11800000);
 801}
 802
 803#ifdef CONFIG_PA20
 804
 805/*
 806 * Currently, all PA20 chips have 18 bit protection IDs, which is the
 807 * limiting factor (space ids are 32 bits).
 808 */
 809
 810#define NR_SPACE_IDS 262144
 811
 812#else
 813
 814/*
 815 * Currently we have a one-to-one relationship between space IDs and
 816 * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
 817 * support 15 bit protection IDs, so that is the limiting factor.
 818 * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
 819 * probably not worth the effort for a special case here.
 820 */
 821
 822#define NR_SPACE_IDS 32768
 823
 824#endif  /* !CONFIG_PA20 */
 825
 826#define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
 827#define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
 828
 829static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
 830static unsigned long dirty_space_id[SID_ARRAY_SIZE];
 831static unsigned long space_id_index;
 832static unsigned long free_space_ids = NR_SPACE_IDS - 1;
 833static unsigned long dirty_space_ids;
 834
 835static DEFINE_SPINLOCK(sid_lock);
 836
 837unsigned long alloc_sid(void)
 838{
 839	unsigned long index;
 840
 841	spin_lock(&sid_lock);
 842
 843	if (free_space_ids == 0) {
 844		if (dirty_space_ids != 0) {
 845			spin_unlock(&sid_lock);
 846			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
 847			spin_lock(&sid_lock);
 848		}
 849		BUG_ON(free_space_ids == 0);
 850	}
 851
 852	free_space_ids--;
 853
 854	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
 855	space_id[BIT_WORD(index)] |= BIT_MASK(index);
 856	space_id_index = index;
 857
 858	spin_unlock(&sid_lock);
 859
 860	return index << SPACEID_SHIFT;
 861}
 862
 863void free_sid(unsigned long spaceid)
 864{
 865	unsigned long index = spaceid >> SPACEID_SHIFT;
 866	unsigned long *dirty_space_offset, mask;
 867
 868	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
 869	mask = BIT_MASK(index);
 870
 871	spin_lock(&sid_lock);
 872
 873	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
 874
 875	*dirty_space_offset |= mask;
 876	dirty_space_ids++;
 877
 878	spin_unlock(&sid_lock);
 879}
 880
 881
 882#ifdef CONFIG_SMP
 883static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
 884{
 885	int i;
 886
 887	/* NOTE: sid_lock must be held upon entry */
 888
 889	*ndirtyptr = dirty_space_ids;
 890	if (dirty_space_ids != 0) {
 891	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
 892		dirty_array[i] = dirty_space_id[i];
 893		dirty_space_id[i] = 0;
 894	    }
 895	    dirty_space_ids = 0;
 896	}
 897
 898	return;
 899}
 900
 901static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
 902{
 903	int i;
 904
 905	/* NOTE: sid_lock must be held upon entry */
 906
 907	if (ndirty != 0) {
 908		for (i = 0; i < SID_ARRAY_SIZE; i++) {
 909			space_id[i] ^= dirty_array[i];
 910		}
 911
 912		free_space_ids += ndirty;
 913		space_id_index = 0;
 914	}
 915}
 916
 917#else /* CONFIG_SMP */
 918
 919static void recycle_sids(void)
 920{
 921	int i;
 922
 923	/* NOTE: sid_lock must be held upon entry */
 924
 925	if (dirty_space_ids != 0) {
 926		for (i = 0; i < SID_ARRAY_SIZE; i++) {
 927			space_id[i] ^= dirty_space_id[i];
 928			dirty_space_id[i] = 0;
 929		}
 930
 931		free_space_ids += dirty_space_ids;
 932		dirty_space_ids = 0;
 933		space_id_index = 0;
 934	}
 935}
 936#endif
 937
 938/*
 939 * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
 940 * purged, we can safely reuse the space ids that were released but
 941 * not flushed from the tlb.
 942 */
 943
 944#ifdef CONFIG_SMP
 945
 946static unsigned long recycle_ndirty;
 947static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
 948static unsigned int recycle_inuse;
 949
 950void flush_tlb_all(void)
 951{
 952	int do_recycle;
 953
 954	do_recycle = 0;
 955	spin_lock(&sid_lock);
 956	__inc_irq_stat(irq_tlb_count);
 957	if (dirty_space_ids > RECYCLE_THRESHOLD) {
 958	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
 959	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
 960	    recycle_inuse++;
 961	    do_recycle++;
 962	}
 963	spin_unlock(&sid_lock);
 964	on_each_cpu(flush_tlb_all_local, NULL, 1);
 965	if (do_recycle) {
 966	    spin_lock(&sid_lock);
 967	    recycle_sids(recycle_ndirty,recycle_dirty_array);
 968	    recycle_inuse = 0;
 969	    spin_unlock(&sid_lock);
 970	}
 971}
 972#else
 973void flush_tlb_all(void)
 974{
 975	spin_lock(&sid_lock);
 976	__inc_irq_stat(irq_tlb_count);
 977	flush_tlb_all_local(NULL);
 978	recycle_sids();
 979	spin_unlock(&sid_lock);
 980}
 981#endif
 982
 983static const pgprot_t protection_map[16] = {
 984	[VM_NONE]					= PAGE_NONE,
 985	[VM_READ]					= PAGE_READONLY,
 986	[VM_WRITE]					= PAGE_NONE,
 987	[VM_WRITE | VM_READ]				= PAGE_READONLY,
 988	[VM_EXEC]					= PAGE_EXECREAD,
 989	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
 990	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
 991	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
 992	[VM_SHARED]					= PAGE_NONE,
 993	[VM_SHARED | VM_READ]				= PAGE_READONLY,
 994	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
 995	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
 996	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
 997	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
 998	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
 999	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
1000};
1001DECLARE_VM_GET_PAGE_PROT
1002
1003#ifdef CONFIG_EXECMEM
1004static struct execmem_info execmem_info __ro_after_init;
1005
1006struct execmem_info __init *execmem_arch_setup(void)
1007{
1008	execmem_info = (struct execmem_info){
1009		.ranges = {
1010			[EXECMEM_DEFAULT] = {
1011				.start	= VMALLOC_START,
1012				.end	= VMALLOC_END,
1013				.pgprot	= PAGE_KERNEL_RWX,
1014				.alignment = 1,
1015			},
1016		},
1017	};
1018
1019	return &execmem_info;
1020}
1021#endif /* CONFIG_EXECMEM */
v6.2
  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
 36extern int  data_start;
 37extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
 38
 39#if CONFIG_PGTABLE_LEVELS == 3
 40pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
 41#endif
 42
 43pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
 44pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
 45
 46static struct resource data_resource = {
 47	.name	= "Kernel data",
 48	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 49};
 50
 51static struct resource code_resource = {
 52	.name	= "Kernel code",
 53	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 54};
 55
 56static struct resource pdcdata_resource = {
 57	.name	= "PDC data (Page Zero)",
 58	.start	= 0,
 59	.end	= 0x9ff,
 60	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
 61};
 62
 63static 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
 69physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
 70int 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
 78static unsigned long mem_limit __read_mostly = MAX_MEM;
 79
 80static 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
109static 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
338static bool kernel_set_to_readonly;
339
340static 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
439void __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
452void 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
491void 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
523void *parisc_vmalloc_start __ro_after_init;
524EXPORT_SYMBOL(parisc_vmalloc_start);
525
526#ifdef CONFIG_PA11
527unsigned long pcxl_dma_start __ro_after_init;
528#endif
529
530void __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
610unsigned long *empty_zero_page __ro_after_init;
611EXPORT_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 */
621static 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
654static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
674static 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
683void __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
721static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
722static unsigned long dirty_space_id[SID_ARRAY_SIZE];
723static unsigned long space_id_index;
724static unsigned long free_space_ids = NR_SPACE_IDS - 1;
725static unsigned long dirty_space_ids;
726
727static DEFINE_SPINLOCK(sid_lock);
728
729unsigned 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
755void 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
775static 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
793static 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
811static 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
838static unsigned long recycle_ndirty;
839static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
840static unsigned int recycle_inuse;
841
842void 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
865void 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
875static const pgprot_t protection_map[16] = {
876	[VM_NONE]					= PAGE_NONE,
877	[VM_READ]					= PAGE_READONLY,
878	[VM_WRITE]					= PAGE_NONE,
879	[VM_WRITE | VM_READ]				= PAGE_READONLY,
880	[VM_EXEC]					= PAGE_EXECREAD,
881	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
882	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
883	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
884	[VM_SHARED]					= PAGE_NONE,
885	[VM_SHARED | VM_READ]				= PAGE_READONLY,
886	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
887	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
888	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
889	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
890	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
891	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
892};
893DECLARE_VM_GET_PAGE_PROT