1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/arch/arm/mm/mmu.c
   4 *
   5 *  Copyright (C) 1995-2005 Russell King
   6 */
   7#include <linux/module.h>
   8#include <linux/kernel.h>
   9#include <linux/errno.h>
  10#include <linux/init.h>
  11#include <linux/mman.h>
  12#include <linux/nodemask.h>
  13#include <linux/memblock.h>
  14#include <linux/fs.h>
  15#include <linux/vmalloc.h>
  16#include <linux/sizes.h>
  17
  18#include <asm/cp15.h>
  19#include <asm/cputype.h>
  20#include <asm/sections.h>
  21#include <asm/cachetype.h>
  22#include <asm/fixmap.h>
  23#include <asm/sections.h>
  24#include <asm/setup.h>
  25#include <asm/smp_plat.h>
  26#include <asm/tlb.h>
  27#include <asm/highmem.h>
  28#include <asm/system_info.h>
  29#include <asm/traps.h>
  30#include <asm/procinfo.h>
  31#include <asm/memory.h>
  32#include <asm/pgalloc.h>
 
  33
  34#include <asm/mach/arch.h>
  35#include <asm/mach/map.h>
  36#include <asm/mach/pci.h>
  37#include <asm/fixmap.h>
  38
  39#include "fault.h"
  40#include "mm.h"
  41#include "tcm.h"
  42
 
 
  43/*
  44 * empty_zero_page is a special page that is used for
  45 * zero-initialized data and COW.
  46 */
  47struct page *empty_zero_page;
  48EXPORT_SYMBOL(empty_zero_page);
  49
  50/*
  51 * The pmd table for the upper-most set of pages.
  52 */
  53pmd_t *top_pmd;
  54
  55pmdval_t user_pmd_table = _PAGE_USER_TABLE;
  56
  57#define CPOLICY_UNCACHED	0
  58#define CPOLICY_BUFFERED	1
  59#define CPOLICY_WRITETHROUGH	2
  60#define CPOLICY_WRITEBACK	3
  61#define CPOLICY_WRITEALLOC	4
  62
  63static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
  64static unsigned int ecc_mask __initdata = 0;
  65pgprot_t pgprot_user;
  66pgprot_t pgprot_kernel;
  67
  68EXPORT_SYMBOL(pgprot_user);
  69EXPORT_SYMBOL(pgprot_kernel);
  70
  71struct cachepolicy {
  72	const char	policy[16];
  73	unsigned int	cr_mask;
  74	pmdval_t	pmd;
  75	pteval_t	pte;
  76};
  77
  78static struct cachepolicy cache_policies[] __initdata = {
  79	{
  80		.policy		= "uncached",
  81		.cr_mask	= CR_W|CR_C,
  82		.pmd		= PMD_SECT_UNCACHED,
  83		.pte		= L_PTE_MT_UNCACHED,
  84	}, {
  85		.policy		= "buffered",
  86		.cr_mask	= CR_C,
  87		.pmd		= PMD_SECT_BUFFERED,
  88		.pte		= L_PTE_MT_BUFFERABLE,
  89	}, {
  90		.policy		= "writethrough",
  91		.cr_mask	= 0,
  92		.pmd		= PMD_SECT_WT,
  93		.pte		= L_PTE_MT_WRITETHROUGH,
  94	}, {
  95		.policy		= "writeback",
  96		.cr_mask	= 0,
  97		.pmd		= PMD_SECT_WB,
  98		.pte		= L_PTE_MT_WRITEBACK,
  99	}, {
 100		.policy		= "writealloc",
 101		.cr_mask	= 0,
 102		.pmd		= PMD_SECT_WBWA,
 103		.pte		= L_PTE_MT_WRITEALLOC,
 104	}
 105};
 106
 107#ifdef CONFIG_CPU_CP15
 108static unsigned long initial_pmd_value __initdata = 0;
 109
 110/*
 111 * Initialise the cache_policy variable with the initial state specified
 112 * via the "pmd" value.  This is used to ensure that on ARMv6 and later,
 113 * the C code sets the page tables up with the same policy as the head
 114 * assembly code, which avoids an illegal state where the TLBs can get
 115 * confused.  See comments in early_cachepolicy() for more information.
 116 */
 117void __init init_default_cache_policy(unsigned long pmd)
 118{
 119	int i;
 120
 121	initial_pmd_value = pmd;
 122
 123	pmd &= PMD_SECT_CACHE_MASK;
 124
 125	for (i = 0; i < ARRAY_SIZE(cache_policies); i++)
 126		if (cache_policies[i].pmd == pmd) {
 127			cachepolicy = i;
 128			break;
 129		}
 130
 131	if (i == ARRAY_SIZE(cache_policies))
 132		pr_err("ERROR: could not find cache policy\n");
 133}
 134
 135/*
 136 * These are useful for identifying cache coherency problems by allowing
 137 * the cache or the cache and writebuffer to be turned off.  (Note: the
 138 * write buffer should not be on and the cache off).
 139 */
 140static int __init early_cachepolicy(char *p)
 141{
 142	int i, selected = -1;
 143
 144	for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
 145		int len = strlen(cache_policies[i].policy);
 146
 147		if (memcmp(p, cache_policies[i].policy, len) == 0) {
 148			selected = i;
 149			break;
 150		}
 151	}
 152
 153	if (selected == -1)
 154		pr_err("ERROR: unknown or unsupported cache policy\n");
 155
 156	/*
 157	 * This restriction is partly to do with the way we boot; it is
 158	 * unpredictable to have memory mapped using two different sets of
 159	 * memory attributes (shared, type, and cache attribs).  We can not
 160	 * change these attributes once the initial assembly has setup the
 161	 * page tables.
 162	 */
 163	if (cpu_architecture() >= CPU_ARCH_ARMv6 && selected != cachepolicy) {
 164		pr_warn("Only cachepolicy=%s supported on ARMv6 and later\n",
 165			cache_policies[cachepolicy].policy);
 166		return 0;
 167	}
 168
 169	if (selected != cachepolicy) {
 170		unsigned long cr = __clear_cr(cache_policies[selected].cr_mask);
 171		cachepolicy = selected;
 172		flush_cache_all();
 173		set_cr(cr);
 174	}
 175	return 0;
 176}
 177early_param("cachepolicy", early_cachepolicy);
 178
 179static int __init early_nocache(char *__unused)
 180{
 181	char *p = "buffered";
 182	pr_warn("nocache is deprecated; use cachepolicy=%s\n", p);
 183	early_cachepolicy(p);
 184	return 0;
 185}
 186early_param("nocache", early_nocache);
 187
 188static int __init early_nowrite(char *__unused)
 189{
 190	char *p = "uncached";
 191	pr_warn("nowb is deprecated; use cachepolicy=%s\n", p);
 192	early_cachepolicy(p);
 193	return 0;
 194}
 195early_param("nowb", early_nowrite);
 196
 197#ifndef CONFIG_ARM_LPAE
 198static int __init early_ecc(char *p)
 199{
 200	if (memcmp(p, "on", 2) == 0)
 201		ecc_mask = PMD_PROTECTION;
 202	else if (memcmp(p, "off", 3) == 0)
 203		ecc_mask = 0;
 204	return 0;
 205}
 206early_param("ecc", early_ecc);
 207#endif
 208
 209#else /* ifdef CONFIG_CPU_CP15 */
 210
 211static int __init early_cachepolicy(char *p)
 212{
 213	pr_warn("cachepolicy kernel parameter not supported without cp15\n");
 
 214}
 215early_param("cachepolicy", early_cachepolicy);
 216
 217static int __init noalign_setup(char *__unused)
 218{
 219	pr_warn("noalign kernel parameter not supported without cp15\n");
 
 220}
 221__setup("noalign", noalign_setup);
 222
 223#endif /* ifdef CONFIG_CPU_CP15 / else */
 224
 225#define PROT_PTE_DEVICE		L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
 226#define PROT_PTE_S2_DEVICE	PROT_PTE_DEVICE
 227#define PROT_SECT_DEVICE	PMD_TYPE_SECT|PMD_SECT_AP_WRITE
 228
 229static struct mem_type mem_types[] __ro_after_init = {
 230	[MT_DEVICE] = {		  /* Strongly ordered / ARMv6 shared device */
 231		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
 232				  L_PTE_SHARED,
 233		.prot_l1	= PMD_TYPE_TABLE,
 234		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_S,
 235		.domain		= DOMAIN_IO,
 236	},
 237	[MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
 238		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
 239		.prot_l1	= PMD_TYPE_TABLE,
 240		.prot_sect	= PROT_SECT_DEVICE,
 241		.domain		= DOMAIN_IO,
 242	},
 243	[MT_DEVICE_CACHED] = {	  /* ioremap_cache */
 244		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
 245		.prot_l1	= PMD_TYPE_TABLE,
 246		.prot_sect	= PROT_SECT_DEVICE | PMD_SECT_WB,
 247		.domain		= DOMAIN_IO,
 248	},
 249	[MT_DEVICE_WC] = {	/* ioremap_wc */
 250		.prot_pte	= PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
 251		.prot_l1	= PMD_TYPE_TABLE,
 252		.prot_sect	= PROT_SECT_DEVICE,
 253		.domain		= DOMAIN_IO,
 254	},
 255	[MT_UNCACHED] = {
 256		.prot_pte	= PROT_PTE_DEVICE,
 257		.prot_l1	= PMD_TYPE_TABLE,
 258		.prot_sect	= PMD_TYPE_SECT | PMD_SECT_XN,
 259		.domain		= DOMAIN_IO,
 260	},
 261	[MT_CACHECLEAN] = {
 262		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
 263		.domain    = DOMAIN_KERNEL,
 264	},
 265#ifndef CONFIG_ARM_LPAE
 266	[MT_MINICLEAN] = {
 267		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
 268		.domain    = DOMAIN_KERNEL,
 269	},
 270#endif
 271	[MT_LOW_VECTORS] = {
 272		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 273				L_PTE_RDONLY,
 274		.prot_l1   = PMD_TYPE_TABLE,
 275		.domain    = DOMAIN_VECTORS,
 276	},
 277	[MT_HIGH_VECTORS] = {
 278		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 279				L_PTE_USER | L_PTE_RDONLY,
 280		.prot_l1   = PMD_TYPE_TABLE,
 281		.domain    = DOMAIN_VECTORS,
 282	},
 283	[MT_MEMORY_RWX] = {
 284		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
 285		.prot_l1   = PMD_TYPE_TABLE,
 286		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
 287		.domain    = DOMAIN_KERNEL,
 288	},
 289	[MT_MEMORY_RW] = {
 290		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 291			     L_PTE_XN,
 292		.prot_l1   = PMD_TYPE_TABLE,
 293		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
 294		.domain    = DOMAIN_KERNEL,
 295	},
 
 
 
 
 
 
 
 
 
 
 
 296	[MT_ROM] = {
 297		.prot_sect = PMD_TYPE_SECT,
 298		.domain    = DOMAIN_KERNEL,
 299	},
 300	[MT_MEMORY_RWX_NONCACHED] = {
 301		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 302				L_PTE_MT_BUFFERABLE,
 303		.prot_l1   = PMD_TYPE_TABLE,
 304		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
 305		.domain    = DOMAIN_KERNEL,
 306	},
 307	[MT_MEMORY_RW_DTCM] = {
 308		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 309				L_PTE_XN,
 310		.prot_l1   = PMD_TYPE_TABLE,
 311		.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
 312		.domain    = DOMAIN_KERNEL,
 313	},
 314	[MT_MEMORY_RWX_ITCM] = {
 315		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
 316		.prot_l1   = PMD_TYPE_TABLE,
 317		.domain    = DOMAIN_KERNEL,
 318	},
 319	[MT_MEMORY_RW_SO] = {
 320		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 321				L_PTE_MT_UNCACHED | L_PTE_XN,
 322		.prot_l1   = PMD_TYPE_TABLE,
 323		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_S |
 324				PMD_SECT_UNCACHED | PMD_SECT_XN,
 325		.domain    = DOMAIN_KERNEL,
 326	},
 327	[MT_MEMORY_DMA_READY] = {
 328		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 329				L_PTE_XN,
 330		.prot_l1   = PMD_TYPE_TABLE,
 331		.domain    = DOMAIN_KERNEL,
 332	},
 333};
 334
 335const struct mem_type *get_mem_type(unsigned int type)
 336{
 337	return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
 338}
 339EXPORT_SYMBOL(get_mem_type);
 340
 341static pte_t *(*pte_offset_fixmap)(pmd_t *dir, unsigned long addr);
 342
 343static pte_t bm_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS]
 344	__aligned(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE) __initdata;
 345
 346static pte_t * __init pte_offset_early_fixmap(pmd_t *dir, unsigned long addr)
 347{
 348	return &bm_pte[pte_index(addr)];
 349}
 350
 351static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr)
 352{
 353	return pte_offset_kernel(dir, addr);
 354}
 355
 356static inline pmd_t * __init fixmap_pmd(unsigned long addr)
 357{
 358	return pmd_off_k(addr);
 359}
 360
 361void __init early_fixmap_init(void)
 362{
 363	pmd_t *pmd;
 364
 365	/*
 366	 * The early fixmap range spans multiple pmds, for which
 367	 * we are not prepared:
 368	 */
 369	BUILD_BUG_ON((__fix_to_virt(__end_of_early_ioremap_region) >> PMD_SHIFT)
 370		     != FIXADDR_TOP >> PMD_SHIFT);
 371
 372	pmd = fixmap_pmd(FIXADDR_TOP);
 373	pmd_populate_kernel(&init_mm, pmd, bm_pte);
 374
 375	pte_offset_fixmap = pte_offset_early_fixmap;
 376}
 377
 378/*
 379 * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range().
 380 * As a result, this can only be called with preemption disabled, as under
 381 * stop_machine().
 382 */
 383void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 384{
 385	unsigned long vaddr = __fix_to_virt(idx);
 386	pte_t *pte = pte_offset_fixmap(pmd_off_k(vaddr), vaddr);
 387
 388	/* Make sure fixmap region does not exceed available allocation. */
 389	BUILD_BUG_ON(FIXADDR_START + (__end_of_fixed_addresses * PAGE_SIZE) >
 390		     FIXADDR_END);
 391	BUG_ON(idx >= __end_of_fixed_addresses);
 392
 393	/* we only support device mappings until pgprot_kernel has been set */
 394	if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) &&
 395		    pgprot_val(pgprot_kernel) == 0))
 396		return;
 397
 398	if (pgprot_val(prot))
 399		set_pte_at(NULL, vaddr, pte,
 400			pfn_pte(phys >> PAGE_SHIFT, prot));
 401	else
 402		pte_clear(NULL, vaddr, pte);
 403	local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
 404}
 405
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 406/*
 407 * Adjust the PMD section entries according to the CPU in use.
 408 */
 409static void __init build_mem_type_table(void)
 410{
 411	struct cachepolicy *cp;
 412	unsigned int cr = get_cr();
 413	pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
 414	int cpu_arch = cpu_architecture();
 415	int i;
 416
 417	if (cpu_arch < CPU_ARCH_ARMv6) {
 418#if defined(CONFIG_CPU_DCACHE_DISABLE)
 419		if (cachepolicy > CPOLICY_BUFFERED)
 420			cachepolicy = CPOLICY_BUFFERED;
 421#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
 422		if (cachepolicy > CPOLICY_WRITETHROUGH)
 423			cachepolicy = CPOLICY_WRITETHROUGH;
 424#endif
 425	}
 426	if (cpu_arch < CPU_ARCH_ARMv5) {
 427		if (cachepolicy >= CPOLICY_WRITEALLOC)
 428			cachepolicy = CPOLICY_WRITEBACK;
 429		ecc_mask = 0;
 430	}
 431
 432	if (is_smp()) {
 433		if (cachepolicy != CPOLICY_WRITEALLOC) {
 434			pr_warn("Forcing write-allocate cache policy for SMP\n");
 435			cachepolicy = CPOLICY_WRITEALLOC;
 436		}
 437		if (!(initial_pmd_value & PMD_SECT_S)) {
 438			pr_warn("Forcing shared mappings for SMP\n");
 439			initial_pmd_value |= PMD_SECT_S;
 440		}
 441	}
 442
 443	/*
 444	 * Strip out features not present on earlier architectures.
 445	 * Pre-ARMv5 CPUs don't have TEX bits.  Pre-ARMv6 CPUs or those
 446	 * without extended page tables don't have the 'Shared' bit.
 447	 */
 448	if (cpu_arch < CPU_ARCH_ARMv5)
 449		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
 450			mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
 451	if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3())
 452		for (i = 0; i < ARRAY_SIZE(mem_types); i++)
 453			mem_types[i].prot_sect &= ~PMD_SECT_S;
 454
 455	/*
 456	 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
 457	 * "update-able on write" bit on ARM610).  However, Xscale and
 458	 * Xscale3 require this bit to be cleared.
 459	 */
 460	if (cpu_is_xscale_family()) {
 461		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
 462			mem_types[i].prot_sect &= ~PMD_BIT4;
 463			mem_types[i].prot_l1 &= ~PMD_BIT4;
 464		}
 465	} else if (cpu_arch < CPU_ARCH_ARMv6) {
 466		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
 467			if (mem_types[i].prot_l1)
 468				mem_types[i].prot_l1 |= PMD_BIT4;
 469			if (mem_types[i].prot_sect)
 470				mem_types[i].prot_sect |= PMD_BIT4;
 471		}
 472	}
 473
 474	/*
 475	 * Mark the device areas according to the CPU/architecture.
 476	 */
 477	if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
 478		if (!cpu_is_xsc3()) {
 479			/*
 480			 * Mark device regions on ARMv6+ as execute-never
 481			 * to prevent speculative instruction fetches.
 482			 */
 483			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
 484			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
 485			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
 486			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;
 487
 488			/* Also setup NX memory mapping */
 489			mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_XN;
 
 490		}
 491		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
 492			/*
 493			 * For ARMv7 with TEX remapping,
 494			 * - shared device is SXCB=1100
 495			 * - nonshared device is SXCB=0100
 496			 * - write combine device mem is SXCB=0001
 497			 * (Uncached Normal memory)
 498			 */
 499			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
 500			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
 501			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
 502		} else if (cpu_is_xsc3()) {
 503			/*
 504			 * For Xscale3,
 505			 * - shared device is TEXCB=00101
 506			 * - nonshared device is TEXCB=01000
 507			 * - write combine device mem is TEXCB=00100
 508			 * (Inner/Outer Uncacheable in xsc3 parlance)
 509			 */
 510			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED;
 511			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
 512			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
 513		} else {
 514			/*
 515			 * For ARMv6 and ARMv7 without TEX remapping,
 516			 * - shared device is TEXCB=00001
 517			 * - nonshared device is TEXCB=01000
 518			 * - write combine device mem is TEXCB=00100
 519			 * (Uncached Normal in ARMv6 parlance).
 520			 */
 521			mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
 522			mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
 523			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
 524		}
 525	} else {
 526		/*
 527		 * On others, write combining is "Uncached/Buffered"
 528		 */
 529		mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
 530	}
 531
 532	/*
 533	 * Now deal with the memory-type mappings
 534	 */
 535	cp = &cache_policies[cachepolicy];
 536	vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
 537
 538#ifndef CONFIG_ARM_LPAE
 539	/*
 540	 * We don't use domains on ARMv6 (since this causes problems with
 541	 * v6/v7 kernels), so we must use a separate memory type for user
 542	 * r/o, kernel r/w to map the vectors page.
 543	 */
 544	if (cpu_arch == CPU_ARCH_ARMv6)
 545		vecs_pgprot |= L_PTE_MT_VECTORS;
 546
 547	/*
 548	 * Check is it with support for the PXN bit
 549	 * in the Short-descriptor translation table format descriptors.
 550	 */
 551	if (cpu_arch == CPU_ARCH_ARMv7 &&
 552		(read_cpuid_ext(CPUID_EXT_MMFR0) & 0xF) >= 4) {
 553		user_pmd_table |= PMD_PXNTABLE;
 554	}
 555#endif
 556
 557	/*
 558	 * ARMv6 and above have extended page tables.
 559	 */
 560	if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
 561#ifndef CONFIG_ARM_LPAE
 562		/*
 563		 * Mark cache clean areas and XIP ROM read only
 564		 * from SVC mode and no access from userspace.
 565		 */
 566		mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
 567		mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
 568		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
 
 569#endif
 570
 571		/*
 572		 * If the initial page tables were created with the S bit
 573		 * set, then we need to do the same here for the same
 574		 * reasons given in early_cachepolicy().
 575		 */
 576		if (initial_pmd_value & PMD_SECT_S) {
 577			user_pgprot |= L_PTE_SHARED;
 578			kern_pgprot |= L_PTE_SHARED;
 579			vecs_pgprot |= L_PTE_SHARED;
 580			mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
 581			mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
 582			mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
 583			mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
 584			mem_types[MT_MEMORY_RWX].prot_sect |= PMD_SECT_S;
 585			mem_types[MT_MEMORY_RWX].prot_pte |= L_PTE_SHARED;
 586			mem_types[MT_MEMORY_RW].prot_sect |= PMD_SECT_S;
 587			mem_types[MT_MEMORY_RW].prot_pte |= L_PTE_SHARED;
 
 
 588			mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
 589			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_S;
 590			mem_types[MT_MEMORY_RWX_NONCACHED].prot_pte |= L_PTE_SHARED;
 591		}
 592	}
 593
 594	/*
 595	 * Non-cacheable Normal - intended for memory areas that must
 596	 * not cause dirty cache line writebacks when used
 597	 */
 598	if (cpu_arch >= CPU_ARCH_ARMv6) {
 599		if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
 600			/* Non-cacheable Normal is XCB = 001 */
 601			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |=
 602				PMD_SECT_BUFFERED;
 603		} else {
 604			/* For both ARMv6 and non-TEX-remapping ARMv7 */
 605			mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |=
 606				PMD_SECT_TEX(1);
 607		}
 608	} else {
 609		mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
 610	}
 611
 612#ifdef CONFIG_ARM_LPAE
 613	/*
 614	 * Do not generate access flag faults for the kernel mappings.
 615	 */
 616	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
 617		mem_types[i].prot_pte |= PTE_EXT_AF;
 618		if (mem_types[i].prot_sect)
 619			mem_types[i].prot_sect |= PMD_SECT_AF;
 620	}
 621	kern_pgprot |= PTE_EXT_AF;
 622	vecs_pgprot |= PTE_EXT_AF;
 623
 624	/*
 625	 * Set PXN for user mappings
 626	 */
 627	user_pgprot |= PTE_EXT_PXN;
 628#endif
 629
 630	for (i = 0; i < 16; i++) {
 631		pteval_t v = pgprot_val(protection_map[i]);
 632		protection_map[i] = __pgprot(v | user_pgprot);
 633	}
 634
 635	mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
 636	mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
 637
 638	pgprot_user   = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
 639	pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
 640				 L_PTE_DIRTY | kern_pgprot);
 641
 642	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
 643	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
 644	mem_types[MT_MEMORY_RWX].prot_sect |= ecc_mask | cp->pmd;
 645	mem_types[MT_MEMORY_RWX].prot_pte |= kern_pgprot;
 646	mem_types[MT_MEMORY_RW].prot_sect |= ecc_mask | cp->pmd;
 647	mem_types[MT_MEMORY_RW].prot_pte |= kern_pgprot;
 
 
 648	mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
 649	mem_types[MT_MEMORY_RWX_NONCACHED].prot_sect |= ecc_mask;
 650	mem_types[MT_ROM].prot_sect |= cp->pmd;
 651
 652	switch (cp->pmd) {
 653	case PMD_SECT_WT:
 654		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
 655		break;
 656	case PMD_SECT_WB:
 657	case PMD_SECT_WBWA:
 658		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
 659		break;
 660	}
 661	pr_info("Memory policy: %sData cache %s\n",
 662		ecc_mask ? "ECC enabled, " : "", cp->policy);
 663
 664	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
 665		struct mem_type *t = &mem_types[i];
 666		if (t->prot_l1)
 667			t->prot_l1 |= PMD_DOMAIN(t->domain);
 668		if (t->prot_sect)
 669			t->prot_sect |= PMD_DOMAIN(t->domain);
 670	}
 671}
 672
 673#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 674pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 675			      unsigned long size, pgprot_t vma_prot)
 676{
 677	if (!pfn_valid(pfn))
 678		return pgprot_noncached(vma_prot);
 679	else if (file->f_flags & O_SYNC)
 680		return pgprot_writecombine(vma_prot);
 681	return vma_prot;
 682}
 683EXPORT_SYMBOL(phys_mem_access_prot);
 684#endif
 685
 686#define vectors_base()	(vectors_high() ? 0xffff0000 : 0)
 687
 688static void __init *early_alloc(unsigned long sz)
 689{
 690	void *ptr = memblock_alloc(sz, sz);
 691
 692	if (!ptr)
 693		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 694		      __func__, sz, sz);
 695
 696	return ptr;
 697}
 698
 699static void *__init late_alloc(unsigned long sz)
 700{
 701	void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz));
 702
 703	if (!ptr || !pgtable_pte_page_ctor(virt_to_page(ptr)))
 704		BUG();
 705	return ptr;
 706}
 707
 708static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr,
 709				unsigned long prot,
 710				void *(*alloc)(unsigned long sz))
 711{
 712	if (pmd_none(*pmd)) {
 713		pte_t *pte = alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
 714		__pmd_populate(pmd, __pa(pte), prot);
 715	}
 716	BUG_ON(pmd_bad(*pmd));
 717	return pte_offset_kernel(pmd, addr);
 718}
 719
 720static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
 721				      unsigned long prot)
 722{
 723	return arm_pte_alloc(pmd, addr, prot, early_alloc);
 724}
 725
 726static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
 727				  unsigned long end, unsigned long pfn,
 728				  const struct mem_type *type,
 729				  void *(*alloc)(unsigned long sz),
 730				  bool ng)
 731{
 732	pte_t *pte = arm_pte_alloc(pmd, addr, type->prot_l1, alloc);
 733	do {
 734		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)),
 735			    ng ? PTE_EXT_NG : 0);
 736		pfn++;
 737	} while (pte++, addr += PAGE_SIZE, addr != end);
 738}
 739
 740static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
 741			unsigned long end, phys_addr_t phys,
 742			const struct mem_type *type, bool ng)
 743{
 744	pmd_t *p = pmd;
 745
 746#ifndef CONFIG_ARM_LPAE
 747	/*
 748	 * In classic MMU format, puds and pmds are folded in to
 749	 * the pgds. pmd_offset gives the PGD entry. PGDs refer to a
 750	 * group of L1 entries making up one logical pointer to
 751	 * an L2 table (2MB), where as PMDs refer to the individual
 752	 * L1 entries (1MB). Hence increment to get the correct
 753	 * offset for odd 1MB sections.
 754	 * (See arch/arm/include/asm/pgtable-2level.h)
 755	 */
 756	if (addr & SECTION_SIZE)
 757		pmd++;
 758#endif
 759	do {
 760		*pmd = __pmd(phys | type->prot_sect | (ng ? PMD_SECT_nG : 0));
 761		phys += SECTION_SIZE;
 762	} while (pmd++, addr += SECTION_SIZE, addr != end);
 763
 764	flush_pmd_entry(p);
 765}
 766
 767static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 768				      unsigned long end, phys_addr_t phys,
 769				      const struct mem_type *type,
 770				      void *(*alloc)(unsigned long sz), bool ng)
 771{
 772	pmd_t *pmd = pmd_offset(pud, addr);
 773	unsigned long next;
 774
 775	do {
 776		/*
 777		 * With LPAE, we must loop over to map
 778		 * all the pmds for the given range.
 779		 */
 780		next = pmd_addr_end(addr, end);
 781
 782		/*
 783		 * Try a section mapping - addr, next and phys must all be
 784		 * aligned to a section boundary.
 785		 */
 786		if (type->prot_sect &&
 787				((addr | next | phys) & ~SECTION_MASK) == 0) {
 788			__map_init_section(pmd, addr, next, phys, type, ng);
 789		} else {
 790			alloc_init_pte(pmd, addr, next,
 791				       __phys_to_pfn(phys), type, alloc, ng);
 792		}
 793
 794		phys += next - addr;
 795
 796	} while (pmd++, addr = next, addr != end);
 797}
 798
 799static void __init alloc_init_pud(p4d_t *p4d, unsigned long addr,
 800				  unsigned long end, phys_addr_t phys,
 801				  const struct mem_type *type,
 802				  void *(*alloc)(unsigned long sz), bool ng)
 803{
 804	pud_t *pud = pud_offset(p4d, addr);
 805	unsigned long next;
 806
 807	do {
 808		next = pud_addr_end(addr, end);
 809		alloc_init_pmd(pud, addr, next, phys, type, alloc, ng);
 810		phys += next - addr;
 811	} while (pud++, addr = next, addr != end);
 812}
 813
 814static void __init alloc_init_p4d(pgd_t *pgd, unsigned long addr,
 815				  unsigned long end, phys_addr_t phys,
 816				  const struct mem_type *type,
 817				  void *(*alloc)(unsigned long sz), bool ng)
 818{
 819	p4d_t *p4d = p4d_offset(pgd, addr);
 820	unsigned long next;
 821
 822	do {
 823		next = p4d_addr_end(addr, end);
 824		alloc_init_pud(p4d, addr, next, phys, type, alloc, ng);
 825		phys += next - addr;
 826	} while (p4d++, addr = next, addr != end);
 827}
 828
 829#ifndef CONFIG_ARM_LPAE
 830static void __init create_36bit_mapping(struct mm_struct *mm,
 831					struct map_desc *md,
 832					const struct mem_type *type,
 833					bool ng)
 834{
 835	unsigned long addr, length, end;
 836	phys_addr_t phys;
 837	pgd_t *pgd;
 838
 839	addr = md->virtual;
 840	phys = __pfn_to_phys(md->pfn);
 841	length = PAGE_ALIGN(md->length);
 842
 843	if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) {
 844		pr_err("MM: CPU does not support supersection mapping for 0x%08llx at 0x%08lx\n",
 845		       (long long)__pfn_to_phys((u64)md->pfn), addr);
 846		return;
 847	}
 848
 849	/* N.B.	ARMv6 supersections are only defined to work with domain 0.
 850	 *	Since domain assignments can in fact be arbitrary, the
 851	 *	'domain == 0' check below is required to insure that ARMv6
 852	 *	supersections are only allocated for domain 0 regardless
 853	 *	of the actual domain assignments in use.
 854	 */
 855	if (type->domain) {
 856		pr_err("MM: invalid domain in supersection mapping for 0x%08llx at 0x%08lx\n",
 857		       (long long)__pfn_to_phys((u64)md->pfn), addr);
 858		return;
 859	}
 860
 861	if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) {
 862		pr_err("MM: cannot create mapping for 0x%08llx at 0x%08lx invalid alignment\n",
 863		       (long long)__pfn_to_phys((u64)md->pfn), addr);
 864		return;
 865	}
 866
 867	/*
 868	 * Shift bits [35:32] of address into bits [23:20] of PMD
 869	 * (See ARMv6 spec).
 870	 */
 871	phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
 872
 873	pgd = pgd_offset(mm, addr);
 874	end = addr + length;
 875	do {
 876		p4d_t *p4d = p4d_offset(pgd, addr);
 877		pud_t *pud = pud_offset(p4d, addr);
 878		pmd_t *pmd = pmd_offset(pud, addr);
 879		int i;
 880
 881		for (i = 0; i < 16; i++)
 882			*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER |
 883				       (ng ? PMD_SECT_nG : 0));
 884
 885		addr += SUPERSECTION_SIZE;
 886		phys += SUPERSECTION_SIZE;
 887		pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
 888	} while (addr != end);
 889}
 890#endif	/* !CONFIG_ARM_LPAE */
 891
 892static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
 893				    void *(*alloc)(unsigned long sz),
 894				    bool ng)
 895{
 896	unsigned long addr, length, end;
 897	phys_addr_t phys;
 898	const struct mem_type *type;
 899	pgd_t *pgd;
 900
 901	type = &mem_types[md->type];
 902
 903#ifndef CONFIG_ARM_LPAE
 904	/*
 905	 * Catch 36-bit addresses
 906	 */
 907	if (md->pfn >= 0x100000) {
 908		create_36bit_mapping(mm, md, type, ng);
 909		return;
 910	}
 911#endif
 912
 913	addr = md->virtual & PAGE_MASK;
 914	phys = __pfn_to_phys(md->pfn);
 915	length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
 916
 917	if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
 918		pr_warn("BUG: map for 0x%08llx at 0x%08lx can not be mapped using pages, ignoring.\n",
 919			(long long)__pfn_to_phys(md->pfn), addr);
 920		return;
 921	}
 922
 923	pgd = pgd_offset(mm, addr);
 924	end = addr + length;
 925	do {
 926		unsigned long next = pgd_addr_end(addr, end);
 927
 928		alloc_init_p4d(pgd, addr, next, phys, type, alloc, ng);
 929
 930		phys += next - addr;
 931		addr = next;
 932	} while (pgd++, addr != end);
 933}
 934
 935/*
 936 * Create the page directory entries and any necessary
 937 * page tables for the mapping specified by `md'.  We
 938 * are able to cope here with varying sizes and address
 939 * offsets, and we take full advantage of sections and
 940 * supersections.
 941 */
 942static void __init create_mapping(struct map_desc *md)
 943{
 944	if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
 945		pr_warn("BUG: not creating mapping for 0x%08llx at 0x%08lx in user region\n",
 946			(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
 947		return;
 948	}
 949
 950	if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
 951	    md->virtual >= PAGE_OFFSET && md->virtual < FIXADDR_START &&
 952	    (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
 953		pr_warn("BUG: mapping for 0x%08llx at 0x%08lx out of vmalloc space\n",
 954			(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
 955	}
 956
 957	__create_mapping(&init_mm, md, early_alloc, false);
 958}
 959
 960void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
 961				bool ng)
 962{
 963#ifdef CONFIG_ARM_LPAE
 964	p4d_t *p4d;
 965	pud_t *pud;
 966
 967	p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
 968	if (WARN_ON(!p4d))
 969		return;
 970	pud = pud_alloc(mm, p4d, md->virtual);
 971	if (WARN_ON(!pud))
 972		return;
 973	pmd_alloc(mm, pud, 0);
 974#endif
 975	__create_mapping(mm, md, late_alloc, ng);
 976}
 977
 978/*
 979 * Create the architecture specific mappings
 980 */
 981void __init iotable_init(struct map_desc *io_desc, int nr)
 982{
 983	struct map_desc *md;
 984	struct vm_struct *vm;
 985	struct static_vm *svm;
 986
 987	if (!nr)
 988		return;
 989
 990	svm = memblock_alloc(sizeof(*svm) * nr, __alignof__(*svm));
 991	if (!svm)
 992		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
 993		      __func__, sizeof(*svm) * nr, __alignof__(*svm));
 994
 995	for (md = io_desc; nr; md++, nr--) {
 996		create_mapping(md);
 997
 998		vm = &svm->vm;
 999		vm->addr = (void *)(md->virtual & PAGE_MASK);
1000		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
1001		vm->phys_addr = __pfn_to_phys(md->pfn);
1002		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
1003		vm->flags |= VM_ARM_MTYPE(md->type);
1004		vm->caller = iotable_init;
1005		add_static_vm_early(svm++);
1006	}
1007}
1008
1009void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
1010				  void *caller)
1011{
1012	struct vm_struct *vm;
1013	struct static_vm *svm;
1014
1015	svm = memblock_alloc(sizeof(*svm), __alignof__(*svm));
1016	if (!svm)
1017		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
1018		      __func__, sizeof(*svm), __alignof__(*svm));
1019
1020	vm = &svm->vm;
1021	vm->addr = (void *)addr;
1022	vm->size = size;
1023	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
1024	vm->caller = caller;
1025	add_static_vm_early(svm);
1026}
1027
1028#ifndef CONFIG_ARM_LPAE
1029
1030/*
1031 * The Linux PMD is made of two consecutive section entries covering 2MB
1032 * (see definition in include/asm/pgtable-2level.h).  However a call to
1033 * create_mapping() may optimize static mappings by using individual
1034 * 1MB section mappings.  This leaves the actual PMD potentially half
1035 * initialized if the top or bottom section entry isn't used, leaving it
1036 * open to problems if a subsequent ioremap() or vmalloc() tries to use
1037 * the virtual space left free by that unused section entry.
1038 *
1039 * Let's avoid the issue by inserting dummy vm entries covering the unused
1040 * PMD halves once the static mappings are in place.
1041 */
1042
1043static void __init pmd_empty_section_gap(unsigned long addr)
1044{
1045	vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
1046}
1047
1048static void __init fill_pmd_gaps(void)
1049{
1050	struct static_vm *svm;
1051	struct vm_struct *vm;
1052	unsigned long addr, next = 0;
1053	pmd_t *pmd;
1054
1055	list_for_each_entry(svm, &static_vmlist, list) {
1056		vm = &svm->vm;
1057		addr = (unsigned long)vm->addr;
1058		if (addr < next)
1059			continue;
1060
1061		/*
1062		 * Check if this vm starts on an odd section boundary.
1063		 * If so and the first section entry for this PMD is free
1064		 * then we block the corresponding virtual address.
1065		 */
1066		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
1067			pmd = pmd_off_k(addr);
1068			if (pmd_none(*pmd))
1069				pmd_empty_section_gap(addr & PMD_MASK);
1070		}
1071
1072		/*
1073		 * Then check if this vm ends on an odd section boundary.
1074		 * If so and the second section entry for this PMD is empty
1075		 * then we block the corresponding virtual address.
1076		 */
1077		addr += vm->size;
1078		if ((addr & ~PMD_MASK) == SECTION_SIZE) {
1079			pmd = pmd_off_k(addr) + 1;
1080			if (pmd_none(*pmd))
1081				pmd_empty_section_gap(addr);
1082		}
1083
1084		/* no need to look at any vm entry until we hit the next PMD */
1085		next = (addr + PMD_SIZE - 1) & PMD_MASK;
1086	}
1087}
1088
1089#else
1090#define fill_pmd_gaps() do { } while (0)
1091#endif
1092
1093#if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
1094static void __init pci_reserve_io(void)
1095{
1096	struct static_vm *svm;
1097
1098	svm = find_static_vm_vaddr((void *)PCI_IO_VIRT_BASE);
1099	if (svm)
1100		return;
1101
1102	vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
1103}
1104#else
1105#define pci_reserve_io() do { } while (0)
1106#endif
1107
1108#ifdef CONFIG_DEBUG_LL
1109void __init debug_ll_io_init(void)
1110{
1111	struct map_desc map;
1112
1113	debug_ll_addr(&map.pfn, &map.virtual);
1114	if (!map.pfn || !map.virtual)
1115		return;
1116	map.pfn = __phys_to_pfn(map.pfn);
1117	map.virtual &= PAGE_MASK;
1118	map.length = PAGE_SIZE;
1119	map.type = MT_DEVICE;
1120	iotable_init(&map, 1);
1121}
1122#endif
1123
1124static void * __initdata vmalloc_min =
1125	(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
1126
1127/*
1128 * vmalloc=size forces the vmalloc area to be exactly 'size'
1129 * bytes. This can be used to increase (or decrease) the vmalloc
1130 * area - the default is 240m.
1131 */
1132static int __init early_vmalloc(char *arg)
1133{
1134	unsigned long vmalloc_reserve = memparse(arg, NULL);
 
1135
1136	if (vmalloc_reserve < SZ_16M) {
1137		vmalloc_reserve = SZ_16M;
1138		pr_warn("vmalloc area too small, limiting to %luMB\n",
1139			vmalloc_reserve >> 20);
1140	}
1141
1142	if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
1143		vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
1144		pr_warn("vmalloc area is too big, limiting to %luMB\n",
 
1145			vmalloc_reserve >> 20);
1146	}
1147
1148	vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
1149	return 0;
1150}
1151early_param("vmalloc", early_vmalloc);
1152
1153phys_addr_t arm_lowmem_limit __initdata = 0;
1154
1155void __init adjust_lowmem_bounds(void)
1156{
1157	phys_addr_t memblock_limit = 0;
1158	u64 vmalloc_limit;
1159	struct memblock_region *reg;
1160	phys_addr_t lowmem_limit = 0;
1161
1162	/*
1163	 * Let's use our own (unoptimized) equivalent of __pa() that is
1164	 * not affected by wrap-arounds when sizeof(phys_addr_t) == 4.
1165	 * The result is used as the upper bound on physical memory address
1166	 * and may itself be outside the valid range for which phys_addr_t
1167	 * and therefore __pa() is defined.
1168	 */
1169	vmalloc_limit = (u64)(uintptr_t)vmalloc_min - PAGE_OFFSET + PHYS_OFFSET;
 
1170
1171	/*
1172	 * The first usable region must be PMD aligned. Mark its start
1173	 * as MEMBLOCK_NOMAP if it isn't
1174	 */
1175	for_each_memblock(memory, reg) {
1176		if (!memblock_is_nomap(reg)) {
1177			if (!IS_ALIGNED(reg->base, PMD_SIZE)) {
1178				phys_addr_t len;
1179
1180				len = round_up(reg->base, PMD_SIZE) - reg->base;
1181				memblock_mark_nomap(reg->base, len);
1182			}
1183			break;
1184		}
 
1185	}
1186
1187	for_each_memblock(memory, reg) {
1188		phys_addr_t block_start = reg->base;
1189		phys_addr_t block_end = reg->base + reg->size;
1190
1191		if (memblock_is_nomap(reg))
1192			continue;
1193
1194		if (reg->base < vmalloc_limit) {
1195			if (block_end > lowmem_limit)
1196				/*
1197				 * Compare as u64 to ensure vmalloc_limit does
1198				 * not get truncated. block_end should always
1199				 * fit in phys_addr_t so there should be no
1200				 * issue with assignment.
1201				 */
1202				lowmem_limit = min_t(u64,
1203							 vmalloc_limit,
1204							 block_end);
1205
1206			/*
1207			 * Find the first non-pmd-aligned page, and point
1208			 * memblock_limit at it. This relies on rounding the
1209			 * limit down to be pmd-aligned, which happens at the
1210			 * end of this function.
1211			 *
1212			 * With this algorithm, the start or end of almost any
1213			 * bank can be non-pmd-aligned. The only exception is
1214			 * that the start of the bank 0 must be section-
1215			 * aligned, since otherwise memory would need to be
1216			 * allocated when mapping the start of bank 0, which
1217			 * occurs before any free memory is mapped.
1218			 */
1219			if (!memblock_limit) {
1220				if (!IS_ALIGNED(block_start, PMD_SIZE))
1221					memblock_limit = block_start;
1222				else if (!IS_ALIGNED(block_end, PMD_SIZE))
1223					memblock_limit = lowmem_limit;
1224			}
1225
1226		}
1227	}
1228
1229	arm_lowmem_limit = lowmem_limit;
1230
1231	high_memory = __va(arm_lowmem_limit - 1) + 1;
1232
1233	if (!memblock_limit)
1234		memblock_limit = arm_lowmem_limit;
1235
1236	/*
1237	 * Round the memblock limit down to a pmd size.  This
1238	 * helps to ensure that we will allocate memory from the
1239	 * last full pmd, which should be mapped.
1240	 */
1241	memblock_limit = round_down(memblock_limit, PMD_SIZE);
1242
1243	if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) {
1244		if (memblock_end_of_DRAM() > arm_lowmem_limit) {
1245			phys_addr_t end = memblock_end_of_DRAM();
1246
1247			pr_notice("Ignoring RAM at %pa-%pa\n",
1248				  &memblock_limit, &end);
1249			pr_notice("Consider using a HIGHMEM enabled kernel.\n");
1250
1251			memblock_remove(memblock_limit, end - memblock_limit);
1252		}
1253	}
1254
1255	memblock_set_current_limit(memblock_limit);
1256}
1257
1258static inline void prepare_page_table(void)
1259{
1260	unsigned long addr;
1261	phys_addr_t end;
1262
1263	/*
1264	 * Clear out all the mappings below the kernel image.
1265	 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1266	for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
1267		pmd_clear(pmd_off_k(addr));
 
1268
1269#ifdef CONFIG_XIP_KERNEL
1270	/* The XIP kernel is mapped in the module area -- skip over it */
1271	addr = ((unsigned long)_exiprom + PMD_SIZE - 1) & PMD_MASK;
1272#endif
1273	for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
1274		pmd_clear(pmd_off_k(addr));
1275
1276	/*
1277	 * Find the end of the first block of lowmem.
1278	 */
1279	end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
1280	if (end >= arm_lowmem_limit)
1281		end = arm_lowmem_limit;
1282
1283	/*
1284	 * Clear out all the kernel space mappings, except for the first
1285	 * memory bank, up to the vmalloc region.
1286	 */
1287	for (addr = __phys_to_virt(end);
1288	     addr < VMALLOC_START; addr += PMD_SIZE)
1289		pmd_clear(pmd_off_k(addr));
1290}
1291
1292#ifdef CONFIG_ARM_LPAE
1293/* the first page is reserved for pgd */
1294#define SWAPPER_PG_DIR_SIZE	(PAGE_SIZE + \
1295				 PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
1296#else
1297#define SWAPPER_PG_DIR_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
1298#endif
1299
1300/*
1301 * Reserve the special regions of memory
1302 */
1303void __init arm_mm_memblock_reserve(void)
1304{
1305	/*
1306	 * Reserve the page tables.  These are already in use,
1307	 * and can only be in node 0.
1308	 */
1309	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE);
1310
1311#ifdef CONFIG_SA1111
1312	/*
1313	 * Because of the SA1111 DMA bug, we want to preserve our
1314	 * precious DMA-able memory...
1315	 */
1316	memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);
1317#endif
1318}
1319
1320/*
1321 * Set up the device mappings.  Since we clear out the page tables for all
1322 * mappings above VMALLOC_START, except early fixmap, we might remove debug
1323 * device mappings.  This means earlycon can be used to debug this function
1324 * Any other function or debugging method which may touch any device _will_
1325 * crash the kernel.
1326 */
1327static void __init devicemaps_init(const struct machine_desc *mdesc)
1328{
1329	struct map_desc map;
1330	unsigned long addr;
1331	void *vectors;
1332
1333	/*
1334	 * Allocate the vector page early.
1335	 */
1336	vectors = early_alloc(PAGE_SIZE * 2);
1337
1338	early_trap_init(vectors);
1339
1340	/*
1341	 * Clear page table except top pmd used by early fixmaps
1342	 */
1343	for (addr = VMALLOC_START; addr < (FIXADDR_TOP & PMD_MASK); addr += PMD_SIZE)
1344		pmd_clear(pmd_off_k(addr));
1345
 
 
 
 
 
 
 
 
 
1346	/*
1347	 * Map the kernel if it is XIP.
1348	 * It is always first in the modulearea.
1349	 */
1350#ifdef CONFIG_XIP_KERNEL
1351	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
1352	map.virtual = MODULES_VADDR;
1353	map.length = ((unsigned long)_exiprom - map.virtual + ~SECTION_MASK) & SECTION_MASK;
1354	map.type = MT_ROM;
1355	create_mapping(&map);
1356#endif
1357
1358	/*
1359	 * Map the cache flushing regions.
1360	 */
1361#ifdef FLUSH_BASE
1362	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
1363	map.virtual = FLUSH_BASE;
1364	map.length = SZ_1M;
1365	map.type = MT_CACHECLEAN;
1366	create_mapping(&map);
1367#endif
1368#ifdef FLUSH_BASE_MINICACHE
1369	map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
1370	map.virtual = FLUSH_BASE_MINICACHE;
1371	map.length = SZ_1M;
1372	map.type = MT_MINICLEAN;
1373	create_mapping(&map);
1374#endif
1375
1376	/*
1377	 * Create a mapping for the machine vectors at the high-vectors
1378	 * location (0xffff0000).  If we aren't using high-vectors, also
1379	 * create a mapping at the low-vectors virtual address.
1380	 */
1381	map.pfn = __phys_to_pfn(virt_to_phys(vectors));
1382	map.virtual = 0xffff0000;
1383	map.length = PAGE_SIZE;
1384#ifdef CONFIG_KUSER_HELPERS
1385	map.type = MT_HIGH_VECTORS;
1386#else
1387	map.type = MT_LOW_VECTORS;
1388#endif
1389	create_mapping(&map);
1390
1391	if (!vectors_high()) {
1392		map.virtual = 0;
1393		map.length = PAGE_SIZE * 2;
1394		map.type = MT_LOW_VECTORS;
1395		create_mapping(&map);
1396	}
1397
1398	/* Now create a kernel read-only mapping */
1399	map.pfn += 1;
1400	map.virtual = 0xffff0000 + PAGE_SIZE;
1401	map.length = PAGE_SIZE;
1402	map.type = MT_LOW_VECTORS;
1403	create_mapping(&map);
1404
1405	/*
1406	 * Ask the machine support to map in the statically mapped devices.
1407	 */
1408	if (mdesc->map_io)
1409		mdesc->map_io();
1410	else
1411		debug_ll_io_init();
1412	fill_pmd_gaps();
1413
1414	/* Reserve fixed i/o space in VMALLOC region */
1415	pci_reserve_io();
1416
1417	/*
1418	 * Finally flush the caches and tlb to ensure that we're in a
1419	 * consistent state wrt the writebuffer.  This also ensures that
1420	 * any write-allocated cache lines in the vector page are written
1421	 * back.  After this point, we can start to touch devices again.
1422	 */
1423	local_flush_tlb_all();
1424	flush_cache_all();
1425
1426	/* Enable asynchronous aborts */
1427	early_abt_enable();
1428}
1429
1430static void __init kmap_init(void)
1431{
1432#ifdef CONFIG_HIGHMEM
1433	pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
1434		PKMAP_BASE, _PAGE_KERNEL_TABLE);
1435#endif
1436
1437	early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START,
1438			_PAGE_KERNEL_TABLE);
1439}
1440
1441static void __init map_lowmem(void)
1442{
1443	struct memblock_region *reg;
1444	phys_addr_t kernel_x_start = round_down(__pa(KERNEL_START), SECTION_SIZE);
1445	phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
1446
1447	/* Map all the lowmem memory banks. */
1448	for_each_memblock(memory, reg) {
1449		phys_addr_t start = reg->base;
1450		phys_addr_t end = start + reg->size;
1451		struct map_desc map;
1452
1453		if (memblock_is_nomap(reg))
1454			continue;
1455
1456		if (end > arm_lowmem_limit)
1457			end = arm_lowmem_limit;
1458		if (start >= end)
1459			break;
1460
1461		if (end < kernel_x_start) {
1462			map.pfn = __phys_to_pfn(start);
1463			map.virtual = __phys_to_virt(start);
1464			map.length = end - start;
1465			map.type = MT_MEMORY_RWX;
1466
1467			create_mapping(&map);
1468		} else if (start >= kernel_x_end) {
1469			map.pfn = __phys_to_pfn(start);
1470			map.virtual = __phys_to_virt(start);
1471			map.length = end - start;
1472			map.type = MT_MEMORY_RW;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1473
1474			create_mapping(&map);
1475		} else {
1476			/* This better cover the entire kernel */
1477			if (start < kernel_x_start) {
 
1478				map.pfn = __phys_to_pfn(start);
1479				map.virtual = __phys_to_virt(start);
1480				map.length = kernel_x_start - start;
1481				map.type = MT_MEMORY_RW;
1482
1483				create_mapping(&map);
1484			}
1485
1486			map.pfn = __phys_to_pfn(kernel_x_start);
1487			map.virtual = __phys_to_virt(kernel_x_start);
1488			map.length = kernel_x_end - kernel_x_start;
1489			map.type = MT_MEMORY_RWX;
1490
1491			create_mapping(&map);
1492
1493			if (kernel_x_end < end) {
1494				map.pfn = __phys_to_pfn(kernel_x_end);
1495				map.virtual = __phys_to_virt(kernel_x_end);
1496				map.length = end - kernel_x_end;
1497				map.type = MT_MEMORY_RW;
1498
1499				create_mapping(&map);
 
1500			}
 
 
 
 
 
 
 
 
 
 
 
 
1501		}
 
 
 
 
 
1502	}
1503}
1504
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1505#ifdef CONFIG_ARM_PV_FIXUP
1506extern unsigned long __atags_pointer;
1507typedef void pgtables_remap(long long offset, unsigned long pgd, void *bdata);
1508pgtables_remap lpae_pgtables_remap_asm;
1509
1510/*
1511 * early_paging_init() recreates boot time page table setup, allowing machines
1512 * to switch over to a high (>4G) address space on LPAE systems
1513 */
1514static void __init early_paging_init(const struct machine_desc *mdesc)
1515{
1516	pgtables_remap *lpae_pgtables_remap;
1517	unsigned long pa_pgd;
1518	unsigned int cr, ttbcr;
1519	long long offset;
1520	void *boot_data;
1521
1522	if (!mdesc->pv_fixup)
1523		return;
1524
1525	offset = mdesc->pv_fixup();
1526	if (offset == 0)
1527		return;
1528
1529	/*
 
 
 
 
 
 
 
1530	 * Get the address of the remap function in the 1:1 identity
1531	 * mapping setup by the early page table assembly code.  We
1532	 * must get this prior to the pv update.  The following barrier
1533	 * ensures that this is complete before we fixup any P:V offsets.
1534	 */
1535	lpae_pgtables_remap = (pgtables_remap *)(unsigned long)__pa(lpae_pgtables_remap_asm);
1536	pa_pgd = __pa(swapper_pg_dir);
1537	boot_data = __va(__atags_pointer);
1538	barrier();
1539
1540	pr_info("Switching physical address space to 0x%08llx\n",
1541		(u64)PHYS_OFFSET + offset);
1542
1543	/* Re-set the phys pfn offset, and the pv offset */
1544	__pv_offset += offset;
1545	__pv_phys_pfn_offset += PFN_DOWN(offset);
1546
1547	/* Run the patch stub to update the constants */
1548	fixup_pv_table(&__pv_table_begin,
1549		(&__pv_table_end - &__pv_table_begin) << 2);
1550
1551	/*
1552	 * We changing not only the virtual to physical mapping, but also
1553	 * the physical addresses used to access memory.  We need to flush
1554	 * all levels of cache in the system with caching disabled to
1555	 * ensure that all data is written back, and nothing is prefetched
1556	 * into the caches.  We also need to prevent the TLB walkers
1557	 * allocating into the caches too.  Note that this is ARMv7 LPAE
1558	 * specific.
1559	 */
1560	cr = get_cr();
1561	set_cr(cr & ~(CR_I | CR_C));
1562	asm("mrc p15, 0, %0, c2, c0, 2" : "=r" (ttbcr));
1563	asm volatile("mcr p15, 0, %0, c2, c0, 2"
1564		: : "r" (ttbcr & ~(3 << 8 | 3 << 10)));
1565	flush_cache_all();
1566
1567	/*
1568	 * Fixup the page tables - this must be in the idmap region as
1569	 * we need to disable the MMU to do this safely, and hence it
1570	 * needs to be assembly.  It's fairly simple, as we're using the
1571	 * temporary tables setup by the initial assembly code.
1572	 */
1573	lpae_pgtables_remap(offset, pa_pgd, boot_data);
1574
1575	/* Re-enable the caches and cacheable TLB walks */
1576	asm volatile("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr));
1577	set_cr(cr);
1578}
1579
1580#else
1581
1582static void __init early_paging_init(const struct machine_desc *mdesc)
1583{
1584	long long offset;
1585
1586	if (!mdesc->pv_fixup)
1587		return;
1588
1589	offset = mdesc->pv_fixup();
1590	if (offset == 0)
1591		return;
1592
1593	pr_crit("Physical address space modification is only to support Keystone2.\n");
1594	pr_crit("Please enable ARM_LPAE and ARM_PATCH_PHYS_VIRT support to use this\n");
1595	pr_crit("feature. Your kernel may crash now, have a good day.\n");
1596	add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
1597}
1598
1599#endif
1600
1601static void __init early_fixmap_shutdown(void)
1602{
1603	int i;
1604	unsigned long va = fix_to_virt(__end_of_permanent_fixed_addresses - 1);
1605
1606	pte_offset_fixmap = pte_offset_late_fixmap;
1607	pmd_clear(fixmap_pmd(va));
1608	local_flush_tlb_kernel_page(va);
1609
1610	for (i = 0; i < __end_of_permanent_fixed_addresses; i++) {
1611		pte_t *pte;
1612		struct map_desc map;
1613
1614		map.virtual = fix_to_virt(i);
1615		pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);
1616
1617		/* Only i/o device mappings are supported ATM */
1618		if (pte_none(*pte) ||
1619		    (pte_val(*pte) & L_PTE_MT_MASK) != L_PTE_MT_DEV_SHARED)
1620			continue;
1621
1622		map.pfn = pte_pfn(*pte);
1623		map.type = MT_DEVICE;
1624		map.length = PAGE_SIZE;
1625
1626		create_mapping(&map);
1627	}
1628}
1629
1630/*
1631 * paging_init() sets up the page tables, initialises the zone memory
1632 * maps, and sets up the zero page, bad page and bad page tables.
1633 */
1634void __init paging_init(const struct machine_desc *mdesc)
1635{
1636	void *zero_page;
1637
 
 
 
1638	prepare_page_table();
1639	map_lowmem();
1640	memblock_set_current_limit(arm_lowmem_limit);
 
 
 
 
 
 
1641	dma_contiguous_remap();
1642	early_fixmap_shutdown();
1643	devicemaps_init(mdesc);
1644	kmap_init();
1645	tcm_init();
1646
1647	top_pmd = pmd_off_k(0xffff0000);
1648
1649	/* allocate the zero page. */
1650	zero_page = early_alloc(PAGE_SIZE);
1651
1652	bootmem_init();
1653
1654	empty_zero_page = virt_to_page(zero_page);
1655	__flush_dcache_page(NULL, empty_zero_page);
1656}
1657
1658void __init early_mm_init(const struct machine_desc *mdesc)
1659{
1660	build_mem_type_table();
1661	early_paging_init(mdesc);
1662}
1663
1664void set_pte_at(struct mm_struct *mm, unsigned long addr,
1665			      pte_t *ptep, pte_t pteval)
1666{
1667	unsigned long ext = 0;
1668
1669	if (addr < TASK_SIZE && pte_valid_user(pteval)) {
1670		if (!pte_special(pteval))
1671			__sync_icache_dcache(pteval);
1672		ext |= PTE_EXT_NG;
1673	}
1674
1675	set_pte_ext(ptep, pteval, ext);
1676}