Linux Audio

Check our new training course

Loading...
Note: File does not exist in v6.8.
   1/*
   2 * PowerPC64 port by Mike Corrigan and Dave Engebretsen
   3 *   {mikejc|engebret}@us.ibm.com
   4 *
   5 *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
   6 *
   7 * SMP scalability work:
   8 *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
   9 * 
  10 *    Module name: htab.c
  11 *
  12 *    Description:
  13 *      PowerPC Hashed Page Table functions
  14 *
  15 * This program is free software; you can redistribute it and/or
  16 * modify it under the terms of the GNU General Public License
  17 * as published by the Free Software Foundation; either version
  18 * 2 of the License, or (at your option) any later version.
  19 */
  20
  21#undef DEBUG
  22#undef DEBUG_LOW
  23
  24#include <linux/spinlock.h>
  25#include <linux/errno.h>
  26#include <linux/sched.h>
  27#include <linux/proc_fs.h>
  28#include <linux/stat.h>
  29#include <linux/sysctl.h>
  30#include <linux/export.h>
  31#include <linux/ctype.h>
  32#include <linux/cache.h>
  33#include <linux/init.h>
  34#include <linux/signal.h>
  35#include <linux/memblock.h>
  36#include <linux/context_tracking.h>
  37
  38#include <asm/processor.h>
  39#include <asm/pgtable.h>
  40#include <asm/mmu.h>
  41#include <asm/mmu_context.h>
  42#include <asm/page.h>
  43#include <asm/types.h>
  44#include <asm/uaccess.h>
  45#include <asm/machdep.h>
  46#include <asm/prom.h>
  47#include <asm/tlbflush.h>
  48#include <asm/io.h>
  49#include <asm/eeh.h>
  50#include <asm/tlb.h>
  51#include <asm/cacheflush.h>
  52#include <asm/cputable.h>
  53#include <asm/sections.h>
  54#include <asm/spu.h>
  55#include <asm/udbg.h>
  56#include <asm/code-patching.h>
  57#include <asm/fadump.h>
  58#include <asm/firmware.h>
  59#include <asm/tm.h>
  60
  61#ifdef DEBUG
  62#define DBG(fmt...) udbg_printf(fmt)
  63#else
  64#define DBG(fmt...)
  65#endif
  66
  67#ifdef DEBUG_LOW
  68#define DBG_LOW(fmt...) udbg_printf(fmt)
  69#else
  70#define DBG_LOW(fmt...)
  71#endif
  72
  73#define KB (1024)
  74#define MB (1024*KB)
  75#define GB (1024L*MB)
  76
  77/*
  78 * Note:  pte   --> Linux PTE
  79 *        HPTE  --> PowerPC Hashed Page Table Entry
  80 *
  81 * Execution context:
  82 *   htab_initialize is called with the MMU off (of course), but
  83 *   the kernel has been copied down to zero so it can directly
  84 *   reference global data.  At this point it is very difficult
  85 *   to print debug info.
  86 *
  87 */
  88
  89#ifdef CONFIG_U3_DART
  90extern unsigned long dart_tablebase;
  91#endif /* CONFIG_U3_DART */
  92
  93static unsigned long _SDR1;
  94struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
  95
  96struct hash_pte *htab_address;
  97unsigned long htab_size_bytes;
  98unsigned long htab_hash_mask;
  99EXPORT_SYMBOL_GPL(htab_hash_mask);
 100int mmu_linear_psize = MMU_PAGE_4K;
 101int mmu_virtual_psize = MMU_PAGE_4K;
 102int mmu_vmalloc_psize = MMU_PAGE_4K;
 103#ifdef CONFIG_SPARSEMEM_VMEMMAP
 104int mmu_vmemmap_psize = MMU_PAGE_4K;
 105#endif
 106int mmu_io_psize = MMU_PAGE_4K;
 107int mmu_kernel_ssize = MMU_SEGSIZE_256M;
 108int mmu_highuser_ssize = MMU_SEGSIZE_256M;
 109u16 mmu_slb_size = 64;
 110EXPORT_SYMBOL_GPL(mmu_slb_size);
 111#ifdef CONFIG_PPC_64K_PAGES
 112int mmu_ci_restrictions;
 113#endif
 114#ifdef CONFIG_DEBUG_PAGEALLOC
 115static u8 *linear_map_hash_slots;
 116static unsigned long linear_map_hash_count;
 117static DEFINE_SPINLOCK(linear_map_hash_lock);
 118#endif /* CONFIG_DEBUG_PAGEALLOC */
 119
 120/* There are definitions of page sizes arrays to be used when none
 121 * is provided by the firmware.
 122 */
 123
 124/* Pre-POWER4 CPUs (4k pages only)
 125 */
 126static struct mmu_psize_def mmu_psize_defaults_old[] = {
 127	[MMU_PAGE_4K] = {
 128		.shift	= 12,
 129		.sllp	= 0,
 130		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
 131		.avpnm	= 0,
 132		.tlbiel = 0,
 133	},
 134};
 135
 136/* POWER4, GPUL, POWER5
 137 *
 138 * Support for 16Mb large pages
 139 */
 140static struct mmu_psize_def mmu_psize_defaults_gp[] = {
 141	[MMU_PAGE_4K] = {
 142		.shift	= 12,
 143		.sllp	= 0,
 144		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
 145		.avpnm	= 0,
 146		.tlbiel = 1,
 147	},
 148	[MMU_PAGE_16M] = {
 149		.shift	= 24,
 150		.sllp	= SLB_VSID_L,
 151		.penc   = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
 152			    [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
 153		.avpnm	= 0x1UL,
 154		.tlbiel = 0,
 155	},
 156};
 157
 158static unsigned long htab_convert_pte_flags(unsigned long pteflags)
 159{
 160	unsigned long rflags = pteflags & 0x1fa;
 161
 162	/* _PAGE_EXEC -> NOEXEC */
 163	if ((pteflags & _PAGE_EXEC) == 0)
 164		rflags |= HPTE_R_N;
 165
 166	/* PP bits. PAGE_USER is already PP bit 0x2, so we only
 167	 * need to add in 0x1 if it's a read-only user page
 168	 */
 169	if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
 170					 (pteflags & _PAGE_DIRTY)))
 171		rflags |= 1;
 172	/*
 173	 * Always add "C" bit for perf. Memory coherence is always enabled
 174	 */
 175	return rflags | HPTE_R_C | HPTE_R_M;
 176}
 177
 178int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 179		      unsigned long pstart, unsigned long prot,
 180		      int psize, int ssize)
 181{
 182	unsigned long vaddr, paddr;
 183	unsigned int step, shift;
 184	int ret = 0;
 185
 186	shift = mmu_psize_defs[psize].shift;
 187	step = 1 << shift;
 188
 189	prot = htab_convert_pte_flags(prot);
 190
 191	DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
 192	    vstart, vend, pstart, prot, psize, ssize);
 193
 194	for (vaddr = vstart, paddr = pstart; vaddr < vend;
 195	     vaddr += step, paddr += step) {
 196		unsigned long hash, hpteg;
 197		unsigned long vsid = get_kernel_vsid(vaddr, ssize);
 198		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
 199		unsigned long tprot = prot;
 200
 201		/*
 202		 * If we hit a bad address return error.
 203		 */
 204		if (!vsid)
 205			return -1;
 206		/* Make kernel text executable */
 207		if (overlaps_kernel_text(vaddr, vaddr + step))
 208			tprot &= ~HPTE_R_N;
 209
 210		/* Make kvm guest trampolines executable */
 211		if (overlaps_kvm_tmp(vaddr, vaddr + step))
 212			tprot &= ~HPTE_R_N;
 213
 214		/*
 215		 * If relocatable, check if it overlaps interrupt vectors that
 216		 * are copied down to real 0. For relocatable kernel
 217		 * (e.g. kdump case) we copy interrupt vectors down to real
 218		 * address 0. Mark that region as executable. This is
 219		 * because on p8 system with relocation on exception feature
 220		 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
 221		 * in order to execute the interrupt handlers in virtual
 222		 * mode the vector region need to be marked as executable.
 223		 */
 224		if ((PHYSICAL_START > MEMORY_START) &&
 225			overlaps_interrupt_vector_text(vaddr, vaddr + step))
 226				tprot &= ~HPTE_R_N;
 227
 228		hash = hpt_hash(vpn, shift, ssize);
 229		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 230
 231		BUG_ON(!ppc_md.hpte_insert);
 232		ret = ppc_md.hpte_insert(hpteg, vpn, paddr, tprot,
 233					 HPTE_V_BOLTED, psize, psize, ssize);
 234
 235		if (ret < 0)
 236			break;
 237#ifdef CONFIG_DEBUG_PAGEALLOC
 238		if ((paddr >> PAGE_SHIFT) < linear_map_hash_count)
 239			linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
 240#endif /* CONFIG_DEBUG_PAGEALLOC */
 241	}
 242	return ret < 0 ? ret : 0;
 243}
 244
 245#ifdef CONFIG_MEMORY_HOTPLUG
 246static int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 247		      int psize, int ssize)
 248{
 249	unsigned long vaddr;
 250	unsigned int step, shift;
 251
 252	shift = mmu_psize_defs[psize].shift;
 253	step = 1 << shift;
 254
 255	if (!ppc_md.hpte_removebolted) {
 256		printk(KERN_WARNING "Platform doesn't implement "
 257				"hpte_removebolted\n");
 258		return -EINVAL;
 259	}
 260
 261	for (vaddr = vstart; vaddr < vend; vaddr += step)
 262		ppc_md.hpte_removebolted(vaddr, psize, ssize);
 263
 264	return 0;
 265}
 266#endif /* CONFIG_MEMORY_HOTPLUG */
 267
 268static int __init htab_dt_scan_seg_sizes(unsigned long node,
 269					 const char *uname, int depth,
 270					 void *data)
 271{
 272	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 273	__be32 *prop;
 274	unsigned long size = 0;
 275
 276	/* We are scanning "cpu" nodes only */
 277	if (type == NULL || strcmp(type, "cpu") != 0)
 278		return 0;
 279
 280	prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
 281	if (prop == NULL)
 282		return 0;
 283	for (; size >= 4; size -= 4, ++prop) {
 284		if (be32_to_cpu(prop[0]) == 40) {
 285			DBG("1T segment support detected\n");
 286			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
 287			return 1;
 288		}
 289	}
 290	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
 291	return 0;
 292}
 293
 294static void __init htab_init_seg_sizes(void)
 295{
 296	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
 297}
 298
 299static int __init get_idx_from_shift(unsigned int shift)
 300{
 301	int idx = -1;
 302
 303	switch (shift) {
 304	case 0xc:
 305		idx = MMU_PAGE_4K;
 306		break;
 307	case 0x10:
 308		idx = MMU_PAGE_64K;
 309		break;
 310	case 0x14:
 311		idx = MMU_PAGE_1M;
 312		break;
 313	case 0x18:
 314		idx = MMU_PAGE_16M;
 315		break;
 316	case 0x22:
 317		idx = MMU_PAGE_16G;
 318		break;
 319	}
 320	return idx;
 321}
 322
 323static int __init htab_dt_scan_page_sizes(unsigned long node,
 324					  const char *uname, int depth,
 325					  void *data)
 326{
 327	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 328	__be32 *prop;
 329	unsigned long size = 0;
 330
 331	/* We are scanning "cpu" nodes only */
 332	if (type == NULL || strcmp(type, "cpu") != 0)
 333		return 0;
 334
 335	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
 336	if (prop != NULL) {
 337		pr_info("Page sizes from device-tree:\n");
 338		size /= 4;
 339		cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
 340		while(size > 0) {
 341			unsigned int base_shift = be32_to_cpu(prop[0]);
 342			unsigned int slbenc = be32_to_cpu(prop[1]);
 343			unsigned int lpnum = be32_to_cpu(prop[2]);
 344			struct mmu_psize_def *def;
 345			int idx, base_idx;
 346
 347			size -= 3; prop += 3;
 348			base_idx = get_idx_from_shift(base_shift);
 349			if (base_idx < 0) {
 350				/*
 351				 * skip the pte encoding also
 352				 */
 353				prop += lpnum * 2; size -= lpnum * 2;
 354				continue;
 355			}
 356			def = &mmu_psize_defs[base_idx];
 357			if (base_idx == MMU_PAGE_16M)
 358				cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
 359
 360			def->shift = base_shift;
 361			if (base_shift <= 23)
 362				def->avpnm = 0;
 363			else
 364				def->avpnm = (1 << (base_shift - 23)) - 1;
 365			def->sllp = slbenc;
 366			/*
 367			 * We don't know for sure what's up with tlbiel, so
 368			 * for now we only set it for 4K and 64K pages
 369			 */
 370			if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
 371				def->tlbiel = 1;
 372			else
 373				def->tlbiel = 0;
 374
 375			while (size > 0 && lpnum) {
 376				unsigned int shift = be32_to_cpu(prop[0]);
 377				int penc  = be32_to_cpu(prop[1]);
 378
 379				prop += 2; size -= 2;
 380				lpnum--;
 381
 382				idx = get_idx_from_shift(shift);
 383				if (idx < 0)
 384					continue;
 385
 386				if (penc == -1)
 387					pr_err("Invalid penc for base_shift=%d "
 388					       "shift=%d\n", base_shift, shift);
 389
 390				def->penc[idx] = penc;
 391				pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
 392					" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
 393					base_shift, shift, def->sllp,
 394					def->avpnm, def->tlbiel, def->penc[idx]);
 395			}
 396		}
 397		return 1;
 398	}
 399	return 0;
 400}
 401
 402#ifdef CONFIG_HUGETLB_PAGE
 403/* Scan for 16G memory blocks that have been set aside for huge pages
 404 * and reserve those blocks for 16G huge pages.
 405 */
 406static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
 407					const char *uname, int depth,
 408					void *data) {
 409	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 410	__be64 *addr_prop;
 411	__be32 *page_count_prop;
 412	unsigned int expected_pages;
 413	long unsigned int phys_addr;
 414	long unsigned int block_size;
 415
 416	/* We are scanning "memory" nodes only */
 417	if (type == NULL || strcmp(type, "memory") != 0)
 418		return 0;
 419
 420	/* This property is the log base 2 of the number of virtual pages that
 421	 * will represent this memory block. */
 422	page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
 423	if (page_count_prop == NULL)
 424		return 0;
 425	expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
 426	addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
 427	if (addr_prop == NULL)
 428		return 0;
 429	phys_addr = be64_to_cpu(addr_prop[0]);
 430	block_size = be64_to_cpu(addr_prop[1]);
 431	if (block_size != (16 * GB))
 432		return 0;
 433	printk(KERN_INFO "Huge page(16GB) memory: "
 434			"addr = 0x%lX size = 0x%lX pages = %d\n",
 435			phys_addr, block_size, expected_pages);
 436	if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
 437		memblock_reserve(phys_addr, block_size * expected_pages);
 438		add_gpage(phys_addr, block_size, expected_pages);
 439	}
 440	return 0;
 441}
 442#endif /* CONFIG_HUGETLB_PAGE */
 443
 444static void mmu_psize_set_default_penc(void)
 445{
 446	int bpsize, apsize;
 447	for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
 448		for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
 449			mmu_psize_defs[bpsize].penc[apsize] = -1;
 450}
 451
 452static void __init htab_init_page_sizes(void)
 453{
 454	int rc;
 455
 456	/* se the invalid penc to -1 */
 457	mmu_psize_set_default_penc();
 458
 459	/* Default to 4K pages only */
 460	memcpy(mmu_psize_defs, mmu_psize_defaults_old,
 461	       sizeof(mmu_psize_defaults_old));
 462
 463	/*
 464	 * Try to find the available page sizes in the device-tree
 465	 */
 466	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
 467	if (rc != 0)  /* Found */
 468		goto found;
 469
 470	/*
 471	 * Not in the device-tree, let's fallback on known size
 472	 * list for 16M capable GP & GR
 473	 */
 474	if (mmu_has_feature(MMU_FTR_16M_PAGE))
 475		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
 476		       sizeof(mmu_psize_defaults_gp));
 477 found:
 478#ifndef CONFIG_DEBUG_PAGEALLOC
 479	/*
 480	 * Pick a size for the linear mapping. Currently, we only support
 481	 * 16M, 1M and 4K which is the default
 482	 */
 483	if (mmu_psize_defs[MMU_PAGE_16M].shift)
 484		mmu_linear_psize = MMU_PAGE_16M;
 485	else if (mmu_psize_defs[MMU_PAGE_1M].shift)
 486		mmu_linear_psize = MMU_PAGE_1M;
 487#endif /* CONFIG_DEBUG_PAGEALLOC */
 488
 489#ifdef CONFIG_PPC_64K_PAGES
 490	/*
 491	 * Pick a size for the ordinary pages. Default is 4K, we support
 492	 * 64K for user mappings and vmalloc if supported by the processor.
 493	 * We only use 64k for ioremap if the processor
 494	 * (and firmware) support cache-inhibited large pages.
 495	 * If not, we use 4k and set mmu_ci_restrictions so that
 496	 * hash_page knows to switch processes that use cache-inhibited
 497	 * mappings to 4k pages.
 498	 */
 499	if (mmu_psize_defs[MMU_PAGE_64K].shift) {
 500		mmu_virtual_psize = MMU_PAGE_64K;
 501		mmu_vmalloc_psize = MMU_PAGE_64K;
 502		if (mmu_linear_psize == MMU_PAGE_4K)
 503			mmu_linear_psize = MMU_PAGE_64K;
 504		if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
 505			/*
 506			 * Don't use 64k pages for ioremap on pSeries, since
 507			 * that would stop us accessing the HEA ethernet.
 508			 */
 509			if (!machine_is(pseries))
 510				mmu_io_psize = MMU_PAGE_64K;
 511		} else
 512			mmu_ci_restrictions = 1;
 513	}
 514#endif /* CONFIG_PPC_64K_PAGES */
 515
 516#ifdef CONFIG_SPARSEMEM_VMEMMAP
 517	/* We try to use 16M pages for vmemmap if that is supported
 518	 * and we have at least 1G of RAM at boot
 519	 */
 520	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
 521	    memblock_phys_mem_size() >= 0x40000000)
 522		mmu_vmemmap_psize = MMU_PAGE_16M;
 523	else if (mmu_psize_defs[MMU_PAGE_64K].shift)
 524		mmu_vmemmap_psize = MMU_PAGE_64K;
 525	else
 526		mmu_vmemmap_psize = MMU_PAGE_4K;
 527#endif /* CONFIG_SPARSEMEM_VMEMMAP */
 528
 529	printk(KERN_DEBUG "Page orders: linear mapping = %d, "
 530	       "virtual = %d, io = %d"
 531#ifdef CONFIG_SPARSEMEM_VMEMMAP
 532	       ", vmemmap = %d"
 533#endif
 534	       "\n",
 535	       mmu_psize_defs[mmu_linear_psize].shift,
 536	       mmu_psize_defs[mmu_virtual_psize].shift,
 537	       mmu_psize_defs[mmu_io_psize].shift
 538#ifdef CONFIG_SPARSEMEM_VMEMMAP
 539	       ,mmu_psize_defs[mmu_vmemmap_psize].shift
 540#endif
 541	       );
 542
 543#ifdef CONFIG_HUGETLB_PAGE
 544	/* Reserve 16G huge page memory sections for huge pages */
 545	of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
 546#endif /* CONFIG_HUGETLB_PAGE */
 547}
 548
 549static int __init htab_dt_scan_pftsize(unsigned long node,
 550				       const char *uname, int depth,
 551				       void *data)
 552{
 553	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 554	__be32 *prop;
 555
 556	/* We are scanning "cpu" nodes only */
 557	if (type == NULL || strcmp(type, "cpu") != 0)
 558		return 0;
 559
 560	prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
 561	if (prop != NULL) {
 562		/* pft_size[0] is the NUMA CEC cookie */
 563		ppc64_pft_size = be32_to_cpu(prop[1]);
 564		return 1;
 565	}
 566	return 0;
 567}
 568
 569static unsigned long __init htab_get_table_size(void)
 570{
 571	unsigned long mem_size, rnd_mem_size, pteg_count, psize;
 572
 573	/* If hash size isn't already provided by the platform, we try to
 574	 * retrieve it from the device-tree. If it's not there neither, we
 575	 * calculate it now based on the total RAM size
 576	 */
 577	if (ppc64_pft_size == 0)
 578		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
 579	if (ppc64_pft_size)
 580		return 1UL << ppc64_pft_size;
 581
 582	/* round mem_size up to next power of 2 */
 583	mem_size = memblock_phys_mem_size();
 584	rnd_mem_size = 1UL << __ilog2(mem_size);
 585	if (rnd_mem_size < mem_size)
 586		rnd_mem_size <<= 1;
 587
 588	/* # pages / 2 */
 589	psize = mmu_psize_defs[mmu_virtual_psize].shift;
 590	pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11);
 591
 592	return pteg_count << 7;
 593}
 594
 595#ifdef CONFIG_MEMORY_HOTPLUG
 596int create_section_mapping(unsigned long start, unsigned long end)
 597{
 598	return htab_bolt_mapping(start, end, __pa(start),
 599				 pgprot_val(PAGE_KERNEL), mmu_linear_psize,
 600				 mmu_kernel_ssize);
 601}
 602
 603int remove_section_mapping(unsigned long start, unsigned long end)
 604{
 605	return htab_remove_mapping(start, end, mmu_linear_psize,
 606			mmu_kernel_ssize);
 607}
 608#endif /* CONFIG_MEMORY_HOTPLUG */
 609
 610#define FUNCTION_TEXT(A)	((*(unsigned long *)(A)))
 611
 612static void __init htab_finish_init(void)
 613{
 614	extern unsigned int *htab_call_hpte_insert1;
 615	extern unsigned int *htab_call_hpte_insert2;
 616	extern unsigned int *htab_call_hpte_remove;
 617	extern unsigned int *htab_call_hpte_updatepp;
 618
 619#ifdef CONFIG_PPC_HAS_HASH_64K
 620	extern unsigned int *ht64_call_hpte_insert1;
 621	extern unsigned int *ht64_call_hpte_insert2;
 622	extern unsigned int *ht64_call_hpte_remove;
 623	extern unsigned int *ht64_call_hpte_updatepp;
 624
 625	patch_branch(ht64_call_hpte_insert1,
 626		FUNCTION_TEXT(ppc_md.hpte_insert),
 627		BRANCH_SET_LINK);
 628	patch_branch(ht64_call_hpte_insert2,
 629		FUNCTION_TEXT(ppc_md.hpte_insert),
 630		BRANCH_SET_LINK);
 631	patch_branch(ht64_call_hpte_remove,
 632		FUNCTION_TEXT(ppc_md.hpte_remove),
 633		BRANCH_SET_LINK);
 634	patch_branch(ht64_call_hpte_updatepp,
 635		FUNCTION_TEXT(ppc_md.hpte_updatepp),
 636		BRANCH_SET_LINK);
 637
 638#endif /* CONFIG_PPC_HAS_HASH_64K */
 639
 640	patch_branch(htab_call_hpte_insert1,
 641		FUNCTION_TEXT(ppc_md.hpte_insert),
 642		BRANCH_SET_LINK);
 643	patch_branch(htab_call_hpte_insert2,
 644		FUNCTION_TEXT(ppc_md.hpte_insert),
 645		BRANCH_SET_LINK);
 646	patch_branch(htab_call_hpte_remove,
 647		FUNCTION_TEXT(ppc_md.hpte_remove),
 648		BRANCH_SET_LINK);
 649	patch_branch(htab_call_hpte_updatepp,
 650		FUNCTION_TEXT(ppc_md.hpte_updatepp),
 651		BRANCH_SET_LINK);
 652}
 653
 654static void __init htab_initialize(void)
 655{
 656	unsigned long table;
 657	unsigned long pteg_count;
 658	unsigned long prot;
 659	unsigned long base = 0, size = 0, limit;
 660	struct memblock_region *reg;
 661
 662	DBG(" -> htab_initialize()\n");
 663
 664	/* Initialize segment sizes */
 665	htab_init_seg_sizes();
 666
 667	/* Initialize page sizes */
 668	htab_init_page_sizes();
 669
 670	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
 671		mmu_kernel_ssize = MMU_SEGSIZE_1T;
 672		mmu_highuser_ssize = MMU_SEGSIZE_1T;
 673		printk(KERN_INFO "Using 1TB segments\n");
 674	}
 675
 676	/*
 677	 * Calculate the required size of the htab.  We want the number of
 678	 * PTEGs to equal one half the number of real pages.
 679	 */ 
 680	htab_size_bytes = htab_get_table_size();
 681	pteg_count = htab_size_bytes >> 7;
 682
 683	htab_hash_mask = pteg_count - 1;
 684
 685	if (firmware_has_feature(FW_FEATURE_LPAR)) {
 686		/* Using a hypervisor which owns the htab */
 687		htab_address = NULL;
 688		_SDR1 = 0; 
 689#ifdef CONFIG_FA_DUMP
 690		/*
 691		 * If firmware assisted dump is active firmware preserves
 692		 * the contents of htab along with entire partition memory.
 693		 * Clear the htab if firmware assisted dump is active so
 694		 * that we dont end up using old mappings.
 695		 */
 696		if (is_fadump_active() && ppc_md.hpte_clear_all)
 697			ppc_md.hpte_clear_all();
 698#endif
 699	} else {
 700		/* Find storage for the HPT.  Must be contiguous in
 701		 * the absolute address space. On cell we want it to be
 702		 * in the first 2 Gig so we can use it for IOMMU hacks.
 703		 */
 704		if (machine_is(cell))
 705			limit = 0x80000000;
 706		else
 707			limit = MEMBLOCK_ALLOC_ANYWHERE;
 708
 709		table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit);
 710
 711		DBG("Hash table allocated at %lx, size: %lx\n", table,
 712		    htab_size_bytes);
 713
 714		htab_address = __va(table);
 715
 716		/* htab absolute addr + encoded htabsize */
 717		_SDR1 = table + __ilog2(pteg_count) - 11;
 718
 719		/* Initialize the HPT with no entries */
 720		memset((void *)table, 0, htab_size_bytes);
 721
 722		/* Set SDR1 */
 723		mtspr(SPRN_SDR1, _SDR1);
 724	}
 725
 726	prot = pgprot_val(PAGE_KERNEL);
 727
 728#ifdef CONFIG_DEBUG_PAGEALLOC
 729	linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
 730	linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count,
 731						    1, ppc64_rma_size));
 732	memset(linear_map_hash_slots, 0, linear_map_hash_count);
 733#endif /* CONFIG_DEBUG_PAGEALLOC */
 734
 735	/* On U3 based machines, we need to reserve the DART area and
 736	 * _NOT_ map it to avoid cache paradoxes as it's remapped non
 737	 * cacheable later on
 738	 */
 739
 740	/* create bolted the linear mapping in the hash table */
 741	for_each_memblock(memory, reg) {
 742		base = (unsigned long)__va(reg->base);
 743		size = reg->size;
 744
 745		DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
 746		    base, size, prot);
 747
 748#ifdef CONFIG_U3_DART
 749		/* Do not map the DART space. Fortunately, it will be aligned
 750		 * in such a way that it will not cross two memblock regions and
 751		 * will fit within a single 16Mb page.
 752		 * The DART space is assumed to be a full 16Mb region even if
 753		 * we only use 2Mb of that space. We will use more of it later
 754		 * for AGP GART. We have to use a full 16Mb large page.
 755		 */
 756		DBG("DART base: %lx\n", dart_tablebase);
 757
 758		if (dart_tablebase != 0 && dart_tablebase >= base
 759		    && dart_tablebase < (base + size)) {
 760			unsigned long dart_table_end = dart_tablebase + 16 * MB;
 761			if (base != dart_tablebase)
 762				BUG_ON(htab_bolt_mapping(base, dart_tablebase,
 763							__pa(base), prot,
 764							mmu_linear_psize,
 765							mmu_kernel_ssize));
 766			if ((base + size) > dart_table_end)
 767				BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
 768							base + size,
 769							__pa(dart_table_end),
 770							 prot,
 771							 mmu_linear_psize,
 772							 mmu_kernel_ssize));
 773			continue;
 774		}
 775#endif /* CONFIG_U3_DART */
 776		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
 777				prot, mmu_linear_psize, mmu_kernel_ssize));
 778	}
 779	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
 780
 781	/*
 782	 * If we have a memory_limit and we've allocated TCEs then we need to
 783	 * explicitly map the TCE area at the top of RAM. We also cope with the
 784	 * case that the TCEs start below memory_limit.
 785	 * tce_alloc_start/end are 16MB aligned so the mapping should work
 786	 * for either 4K or 16MB pages.
 787	 */
 788	if (tce_alloc_start) {
 789		tce_alloc_start = (unsigned long)__va(tce_alloc_start);
 790		tce_alloc_end = (unsigned long)__va(tce_alloc_end);
 791
 792		if (base + size >= tce_alloc_start)
 793			tce_alloc_start = base + size + 1;
 794
 795		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
 796					 __pa(tce_alloc_start), prot,
 797					 mmu_linear_psize, mmu_kernel_ssize));
 798	}
 799
 800	htab_finish_init();
 801
 802	DBG(" <- htab_initialize()\n");
 803}
 804#undef KB
 805#undef MB
 806
 807void __init early_init_mmu(void)
 808{
 809	/* Setup initial STAB address in the PACA */
 810	get_paca()->stab_real = __pa((u64)&initial_stab);
 811	get_paca()->stab_addr = (u64)&initial_stab;
 812
 813	/* Initialize the MMU Hash table and create the linear mapping
 814	 * of memory. Has to be done before stab/slb initialization as
 815	 * this is currently where the page size encoding is obtained
 816	 */
 817	htab_initialize();
 818
 819	/* Initialize stab / SLB management */
 820	if (mmu_has_feature(MMU_FTR_SLB))
 821		slb_initialize();
 822	else
 823		stab_initialize(get_paca()->stab_real);
 824}
 825
 826#ifdef CONFIG_SMP
 827void early_init_mmu_secondary(void)
 828{
 829	/* Initialize hash table for that CPU */
 830	if (!firmware_has_feature(FW_FEATURE_LPAR))
 831		mtspr(SPRN_SDR1, _SDR1);
 832
 833	/* Initialize STAB/SLB. We use a virtual address as it works
 834	 * in real mode on pSeries.
 835	 */
 836	if (mmu_has_feature(MMU_FTR_SLB))
 837		slb_initialize();
 838	else
 839		stab_initialize(get_paca()->stab_addr);
 840}
 841#endif /* CONFIG_SMP */
 842
 843/*
 844 * Called by asm hashtable.S for doing lazy icache flush
 845 */
 846unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
 847{
 848	struct page *page;
 849
 850	if (!pfn_valid(pte_pfn(pte)))
 851		return pp;
 852
 853	page = pte_page(pte);
 854
 855	/* page is dirty */
 856	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
 857		if (trap == 0x400) {
 858			flush_dcache_icache_page(page);
 859			set_bit(PG_arch_1, &page->flags);
 860		} else
 861			pp |= HPTE_R_N;
 862	}
 863	return pp;
 864}
 865
 866#ifdef CONFIG_PPC_MM_SLICES
 867unsigned int get_paca_psize(unsigned long addr)
 868{
 869	u64 lpsizes;
 870	unsigned char *hpsizes;
 871	unsigned long index, mask_index;
 872
 873	if (addr < SLICE_LOW_TOP) {
 874		lpsizes = get_paca()->context.low_slices_psize;
 875		index = GET_LOW_SLICE_INDEX(addr);
 876		return (lpsizes >> (index * 4)) & 0xF;
 877	}
 878	hpsizes = get_paca()->context.high_slices_psize;
 879	index = GET_HIGH_SLICE_INDEX(addr);
 880	mask_index = index & 0x1;
 881	return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
 882}
 883
 884#else
 885unsigned int get_paca_psize(unsigned long addr)
 886{
 887	return get_paca()->context.user_psize;
 888}
 889#endif
 890
 891/*
 892 * Demote a segment to using 4k pages.
 893 * For now this makes the whole process use 4k pages.
 894 */
 895#ifdef CONFIG_PPC_64K_PAGES
 896void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
 897{
 898	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
 899		return;
 900	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
 901#ifdef CONFIG_SPU_BASE
 902	spu_flush_all_slbs(mm);
 903#endif
 904	if (get_paca_psize(addr) != MMU_PAGE_4K) {
 905		get_paca()->context = mm->context;
 906		slb_flush_and_rebolt();
 907	}
 908}
 909#endif /* CONFIG_PPC_64K_PAGES */
 910
 911#ifdef CONFIG_PPC_SUBPAGE_PROT
 912/*
 913 * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
 914 * Userspace sets the subpage permissions using the subpage_prot system call.
 915 *
 916 * Result is 0: full permissions, _PAGE_RW: read-only,
 917 * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access.
 918 */
 919static int subpage_protection(struct mm_struct *mm, unsigned long ea)
 920{
 921	struct subpage_prot_table *spt = &mm->context.spt;
 922	u32 spp = 0;
 923	u32 **sbpm, *sbpp;
 924
 925	if (ea >= spt->maxaddr)
 926		return 0;
 927	if (ea < 0x100000000UL) {
 928		/* addresses below 4GB use spt->low_prot */
 929		sbpm = spt->low_prot;
 930	} else {
 931		sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
 932		if (!sbpm)
 933			return 0;
 934	}
 935	sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
 936	if (!sbpp)
 937		return 0;
 938	spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
 939
 940	/* extract 2-bit bitfield for this 4k subpage */
 941	spp >>= 30 - 2 * ((ea >> 12) & 0xf);
 942
 943	/* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */
 944	spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0);
 945	return spp;
 946}
 947
 948#else /* CONFIG_PPC_SUBPAGE_PROT */
 949static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
 950{
 951	return 0;
 952}
 953#endif
 954
 955void hash_failure_debug(unsigned long ea, unsigned long access,
 956			unsigned long vsid, unsigned long trap,
 957			int ssize, int psize, int lpsize, unsigned long pte)
 958{
 959	if (!printk_ratelimit())
 960		return;
 961	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
 962		ea, access, current->comm);
 963	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
 964		trap, vsid, ssize, psize, lpsize, pte);
 965}
 966
 967/* Result code is:
 968 *  0 - handled
 969 *  1 - normal page fault
 970 * -1 - critical hash insertion error
 971 * -2 - access not permitted by subpage protection mechanism
 972 */
 973int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 974{
 975	enum ctx_state prev_state = exception_enter();
 976	pgd_t *pgdir;
 977	unsigned long vsid;
 978	struct mm_struct *mm;
 979	pte_t *ptep;
 980	unsigned hugeshift;
 981	const struct cpumask *tmp;
 982	int rc, user_region = 0, local = 0;
 983	int psize, ssize;
 984
 985	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
 986		ea, access, trap);
 987
 988	/* Get region & vsid */
 989 	switch (REGION_ID(ea)) {
 990	case USER_REGION_ID:
 991		user_region = 1;
 992		mm = current->mm;
 993		if (! mm) {
 994			DBG_LOW(" user region with no mm !\n");
 995			rc = 1;
 996			goto bail;
 997		}
 998		psize = get_slice_psize(mm, ea);
 999		ssize = user_segment_size(ea);
1000		vsid = get_vsid(mm->context.id, ea, ssize);
1001		break;
1002	case VMALLOC_REGION_ID:
1003		mm = &init_mm;
1004		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1005		if (ea < VMALLOC_END)
1006			psize = mmu_vmalloc_psize;
1007		else
1008			psize = mmu_io_psize;
1009		ssize = mmu_kernel_ssize;
1010		break;
1011	default:
1012		/* Not a valid range
1013		 * Send the problem up to do_page_fault 
1014		 */
1015		rc = 1;
1016		goto bail;
1017	}
1018	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
1019
1020	/* Bad address. */
1021	if (!vsid) {
1022		DBG_LOW("Bad address!\n");
1023		rc = 1;
1024		goto bail;
1025	}
1026	/* Get pgdir */
1027	pgdir = mm->pgd;
1028	if (pgdir == NULL) {
1029		rc = 1;
1030		goto bail;
1031	}
1032
1033	/* Check CPU locality */
1034	tmp = cpumask_of(smp_processor_id());
1035	if (user_region && cpumask_equal(mm_cpumask(mm), tmp))
1036		local = 1;
1037
1038#ifndef CONFIG_PPC_64K_PAGES
1039	/* If we use 4K pages and our psize is not 4K, then we might
1040	 * be hitting a special driver mapping, and need to align the
1041	 * address before we fetch the PTE.
1042	 *
1043	 * It could also be a hugepage mapping, in which case this is
1044	 * not necessary, but it's not harmful, either.
1045	 */
1046	if (psize != MMU_PAGE_4K)
1047		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
1048#endif /* CONFIG_PPC_64K_PAGES */
1049
1050	/* Get PTE and page size from page tables */
1051	ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
1052	if (ptep == NULL || !pte_present(*ptep)) {
1053		DBG_LOW(" no PTE !\n");
1054		rc = 1;
1055		goto bail;
1056	}
1057
1058	/* Add _PAGE_PRESENT to the required access perm */
1059	access |= _PAGE_PRESENT;
1060
1061	/* Pre-check access permissions (will be re-checked atomically
1062	 * in __hash_page_XX but this pre-check is a fast path
1063	 */
1064	if (access & ~pte_val(*ptep)) {
1065		DBG_LOW(" no access !\n");
1066		rc = 1;
1067		goto bail;
1068	}
1069
1070	if (hugeshift) {
1071		if (pmd_trans_huge(*(pmd_t *)ptep))
1072			rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
1073					     trap, local, ssize, psize);
1074#ifdef CONFIG_HUGETLB_PAGE
1075		else
1076			rc = __hash_page_huge(ea, access, vsid, ptep, trap,
1077					      local, ssize, hugeshift, psize);
1078#else
1079		else {
1080			/*
1081			 * if we have hugeshift, and is not transhuge with
1082			 * hugetlb disabled, something is really wrong.
1083			 */
1084			rc = 1;
1085			WARN_ON(1);
1086		}
1087#endif
1088		goto bail;
1089	}
1090
1091#ifndef CONFIG_PPC_64K_PAGES
1092	DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1093#else
1094	DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1095		pte_val(*(ptep + PTRS_PER_PTE)));
1096#endif
1097	/* Do actual hashing */
1098#ifdef CONFIG_PPC_64K_PAGES
1099	/* If _PAGE_4K_PFN is set, make sure this is a 4k segment */
1100	if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1101		demote_segment_4k(mm, ea);
1102		psize = MMU_PAGE_4K;
1103	}
1104
1105	/* If this PTE is non-cacheable and we have restrictions on
1106	 * using non cacheable large pages, then we switch to 4k
1107	 */
1108	if (mmu_ci_restrictions && psize == MMU_PAGE_64K &&
1109	    (pte_val(*ptep) & _PAGE_NO_CACHE)) {
1110		if (user_region) {
1111			demote_segment_4k(mm, ea);
1112			psize = MMU_PAGE_4K;
1113		} else if (ea < VMALLOC_END) {
1114			/*
1115			 * some driver did a non-cacheable mapping
1116			 * in vmalloc space, so switch vmalloc
1117			 * to 4k pages
1118			 */
1119			printk(KERN_ALERT "Reducing vmalloc segment "
1120			       "to 4kB pages because of "
1121			       "non-cacheable mapping\n");
1122			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1123#ifdef CONFIG_SPU_BASE
1124			spu_flush_all_slbs(mm);
1125#endif
1126		}
1127	}
1128	if (user_region) {
1129		if (psize != get_paca_psize(ea)) {
1130			get_paca()->context = mm->context;
1131			slb_flush_and_rebolt();
1132		}
1133	} else if (get_paca()->vmalloc_sllp !=
1134		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1135		get_paca()->vmalloc_sllp =
1136			mmu_psize_defs[mmu_vmalloc_psize].sllp;
1137		slb_vmalloc_update();
1138	}
1139#endif /* CONFIG_PPC_64K_PAGES */
1140
1141#ifdef CONFIG_PPC_HAS_HASH_64K
1142	if (psize == MMU_PAGE_64K)
1143		rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
1144	else
1145#endif /* CONFIG_PPC_HAS_HASH_64K */
1146	{
1147		int spp = subpage_protection(mm, ea);
1148		if (access & spp)
1149			rc = -2;
1150		else
1151			rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1152					    local, ssize, spp);
1153	}
1154
1155	/* Dump some info in case of hash insertion failure, they should
1156	 * never happen so it is really useful to know if/when they do
1157	 */
1158	if (rc == -1)
1159		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1160				   psize, pte_val(*ptep));
1161#ifndef CONFIG_PPC_64K_PAGES
1162	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1163#else
1164	DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1165		pte_val(*(ptep + PTRS_PER_PTE)));
1166#endif
1167	DBG_LOW(" -> rc=%d\n", rc);
1168
1169bail:
1170	exception_exit(prev_state);
1171	return rc;
1172}
1173EXPORT_SYMBOL_GPL(hash_page);
1174
1175void hash_preload(struct mm_struct *mm, unsigned long ea,
1176		  unsigned long access, unsigned long trap)
1177{
1178	int hugepage_shift;
1179	unsigned long vsid;
1180	pgd_t *pgdir;
1181	pte_t *ptep;
1182	unsigned long flags;
1183	int rc, ssize, local = 0;
1184
1185	BUG_ON(REGION_ID(ea) != USER_REGION_ID);
1186
1187#ifdef CONFIG_PPC_MM_SLICES
1188	/* We only prefault standard pages for now */
1189	if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize))
1190		return;
1191#endif
1192
1193	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1194		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
1195
1196	/* Get Linux PTE if available */
1197	pgdir = mm->pgd;
1198	if (pgdir == NULL)
1199		return;
1200
1201	/* Get VSID */
1202	ssize = user_segment_size(ea);
1203	vsid = get_vsid(mm->context.id, ea, ssize);
1204	if (!vsid)
1205		return;
1206	/*
1207	 * Hash doesn't like irqs. Walking linux page table with irq disabled
1208	 * saves us from holding multiple locks.
1209	 */
1210	local_irq_save(flags);
1211
1212	/*
1213	 * THP pages use update_mmu_cache_pmd. We don't do
1214	 * hash preload there. Hence can ignore THP here
1215	 */
1216	ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugepage_shift);
1217	if (!ptep)
1218		goto out_exit;
1219
1220	WARN_ON(hugepage_shift);
1221#ifdef CONFIG_PPC_64K_PAGES
1222	/* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
1223	 * a 64K kernel), then we don't preload, hash_page() will take
1224	 * care of it once we actually try to access the page.
1225	 * That way we don't have to duplicate all of the logic for segment
1226	 * page size demotion here
1227	 */
1228	if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
1229		goto out_exit;
1230#endif /* CONFIG_PPC_64K_PAGES */
1231
1232	/* Is that local to this CPU ? */
1233	if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
1234		local = 1;
1235
1236	/* Hash it in */
1237#ifdef CONFIG_PPC_HAS_HASH_64K
1238	if (mm->context.user_psize == MMU_PAGE_64K)
1239		rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
1240	else
1241#endif /* CONFIG_PPC_HAS_HASH_64K */
1242		rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
1243				    subpage_protection(mm, ea));
1244
1245	/* Dump some info in case of hash insertion failure, they should
1246	 * never happen so it is really useful to know if/when they do
1247	 */
1248	if (rc == -1)
1249		hash_failure_debug(ea, access, vsid, trap, ssize,
1250				   mm->context.user_psize,
1251				   mm->context.user_psize,
1252				   pte_val(*ptep));
1253out_exit:
1254	local_irq_restore(flags);
1255}
1256
1257/* WARNING: This is called from hash_low_64.S, if you change this prototype,
1258 *          do not forget to update the assembly call site !
1259 */
1260void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
1261		     int local)
1262{
1263	unsigned long hash, index, shift, hidx, slot;
1264
1265	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
1266	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
1267		hash = hpt_hash(vpn, shift, ssize);
1268		hidx = __rpte_to_hidx(pte, index);
1269		if (hidx & _PTEIDX_SECONDARY)
1270			hash = ~hash;
1271		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1272		slot += hidx & _PTEIDX_GROUP_IX;
1273		DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
1274		/*
1275		 * We use same base page size and actual psize, because we don't
1276		 * use these functions for hugepage
1277		 */
1278		ppc_md.hpte_invalidate(slot, vpn, psize, psize, ssize, local);
1279	} pte_iterate_hashed_end();
1280
1281#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1282	/* Transactions are not aborted by tlbiel, only tlbie.
1283	 * Without, syncing a page back to a block device w/ PIO could pick up
1284	 * transactional data (bad!) so we force an abort here.  Before the
1285	 * sync the page will be made read-only, which will flush_hash_page.
1286	 * BIG ISSUE here: if the kernel uses a page from userspace without
1287	 * unmapping it first, it may see the speculated version.
1288	 */
1289	if (local && cpu_has_feature(CPU_FTR_TM) &&
1290	    current->thread.regs &&
1291	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
1292		tm_enable();
1293		tm_abort(TM_CAUSE_TLBI);
1294	}
1295#endif
1296}
1297
1298void flush_hash_range(unsigned long number, int local)
1299{
1300	if (ppc_md.flush_hash_range)
1301		ppc_md.flush_hash_range(number, local);
1302	else {
1303		int i;
1304		struct ppc64_tlb_batch *batch =
1305			&__get_cpu_var(ppc64_tlb_batch);
1306
1307		for (i = 0; i < number; i++)
1308			flush_hash_page(batch->vpn[i], batch->pte[i],
1309					batch->psize, batch->ssize, local);
1310	}
1311}
1312
1313/*
1314 * low_hash_fault is called when we the low level hash code failed
1315 * to instert a PTE due to an hypervisor error
1316 */
1317void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1318{
1319	enum ctx_state prev_state = exception_enter();
1320
1321	if (user_mode(regs)) {
1322#ifdef CONFIG_PPC_SUBPAGE_PROT
1323		if (rc == -2)
1324			_exception(SIGSEGV, regs, SEGV_ACCERR, address);
1325		else
1326#endif
1327			_exception(SIGBUS, regs, BUS_ADRERR, address);
1328	} else
1329		bad_page_fault(regs, address, SIGBUS);
1330
1331	exception_exit(prev_state);
1332}
1333
1334long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
1335			   unsigned long pa, unsigned long rflags,
1336			   unsigned long vflags, int psize, int ssize)
1337{
1338	unsigned long hpte_group;
1339	long slot;
1340
1341repeat:
1342	hpte_group = ((hash & htab_hash_mask) *
1343		       HPTES_PER_GROUP) & ~0x7UL;
1344
1345	/* Insert into the hash table, primary slot */
1346	slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
1347				  psize, psize, ssize);
1348
1349	/* Primary is full, try the secondary */
1350	if (unlikely(slot == -1)) {
1351		hpte_group = ((~hash & htab_hash_mask) *
1352			      HPTES_PER_GROUP) & ~0x7UL;
1353		slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags,
1354					  vflags | HPTE_V_SECONDARY,
1355					  psize, psize, ssize);
1356		if (slot == -1) {
1357			if (mftb() & 0x1)
1358				hpte_group = ((hash & htab_hash_mask) *
1359					      HPTES_PER_GROUP)&~0x7UL;
1360
1361			ppc_md.hpte_remove(hpte_group);
1362			goto repeat;
1363		}
1364	}
1365
1366	return slot;
1367}
1368
1369#ifdef CONFIG_DEBUG_PAGEALLOC
1370static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1371{
1372	unsigned long hash;
1373	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1374	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1375	unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL);
1376	long ret;
1377
1378	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1379
1380	/* Don't create HPTE entries for bad address */
1381	if (!vsid)
1382		return;
1383
1384	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
1385				    HPTE_V_BOLTED,
1386				    mmu_linear_psize, mmu_kernel_ssize);
1387
1388	BUG_ON (ret < 0);
1389	spin_lock(&linear_map_hash_lock);
1390	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1391	linear_map_hash_slots[lmi] = ret | 0x80;
1392	spin_unlock(&linear_map_hash_lock);
1393}
1394
1395static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1396{
1397	unsigned long hash, hidx, slot;
1398	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1399	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1400
1401	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1402	spin_lock(&linear_map_hash_lock);
1403	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1404	hidx = linear_map_hash_slots[lmi] & 0x7f;
1405	linear_map_hash_slots[lmi] = 0;
1406	spin_unlock(&linear_map_hash_lock);
1407	if (hidx & _PTEIDX_SECONDARY)
1408		hash = ~hash;
1409	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1410	slot += hidx & _PTEIDX_GROUP_IX;
1411	ppc_md.hpte_invalidate(slot, vpn, mmu_linear_psize, mmu_linear_psize,
1412			       mmu_kernel_ssize, 0);
1413}
1414
1415void kernel_map_pages(struct page *page, int numpages, int enable)
1416{
1417	unsigned long flags, vaddr, lmi;
1418	int i;
1419
1420	local_irq_save(flags);
1421	for (i = 0; i < numpages; i++, page++) {
1422		vaddr = (unsigned long)page_address(page);
1423		lmi = __pa(vaddr) >> PAGE_SHIFT;
1424		if (lmi >= linear_map_hash_count)
1425			continue;
1426		if (enable)
1427			kernel_map_linear_page(vaddr, lmi);
1428		else
1429			kernel_unmap_linear_page(vaddr, lmi);
1430	}
1431	local_irq_restore(flags);
1432}
1433#endif /* CONFIG_DEBUG_PAGEALLOC */
1434
1435void setup_initial_memory_limit(phys_addr_t first_memblock_base,
1436				phys_addr_t first_memblock_size)
1437{
1438	/* We don't currently support the first MEMBLOCK not mapping 0
1439	 * physical on those processors
1440	 */
1441	BUG_ON(first_memblock_base != 0);
1442
1443	/* On LPAR systems, the first entry is our RMA region,
1444	 * non-LPAR 64-bit hash MMU systems don't have a limitation
1445	 * on real mode access, but using the first entry works well
1446	 * enough. We also clamp it to 1G to avoid some funky things
1447	 * such as RTAS bugs etc...
1448	 */
1449	ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
1450
1451	/* Finally limit subsequent allocations */
1452	memblock_set_current_limit(ppc64_rma_size);
1453}