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v6.13.7
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Machine specific setup for xen
   4 *
   5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
   6 */
   7
   8#include <linux/init.h>
   9#include <linux/iscsi_ibft.h>
  10#include <linux/sched.h>
  11#include <linux/kstrtox.h>
  12#include <linux/mm.h>
  13#include <linux/pm.h>
  14#include <linux/memblock.h>
  15#include <linux/cpuidle.h>
  16#include <linux/cpufreq.h>
  17#include <linux/memory_hotplug.h>
  18#include <linux/acpi.h>
  19
  20#include <asm/elf.h>
  21#include <asm/vdso.h>
  22#include <asm/e820/api.h>
  23#include <asm/setup.h>
 
  24#include <asm/numa.h>
  25#include <asm/idtentry.h>
  26#include <asm/xen/hypervisor.h>
  27#include <asm/xen/hypercall.h>
  28
  29#include <xen/xen.h>
  30#include <xen/page.h>
  31#include <xen/interface/callback.h>
  32#include <xen/interface/memory.h>
  33#include <xen/interface/physdev.h>
  34#include <xen/features.h>
  35#include <xen/hvc-console.h>
  36#include "xen-ops.h"
 
 
  37
  38#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
  39
 
 
 
  40/* Number of pages released from the initial allocation. */
  41unsigned long xen_released_pages;
  42
  43/* Memory map would allow PCI passthrough. */
  44bool xen_pv_pci_possible;
  45
  46/* E820 map used during setting up memory. */
  47static struct e820_table xen_e820_table __initdata;
  48
  49/* Number of initially usable memory pages. */
  50static unsigned long ini_nr_pages __initdata;
  51
  52/*
  53 * Buffer used to remap identity mapped pages. We only need the virtual space.
  54 * The physical page behind this address is remapped as needed to different
  55 * buffer pages.
  56 */
  57#define REMAP_SIZE	(P2M_PER_PAGE - 3)
  58static struct {
  59	unsigned long	next_area_mfn;
  60	unsigned long	target_pfn;
  61	unsigned long	size;
  62	unsigned long	mfns[REMAP_SIZE];
  63} xen_remap_buf __initdata __aligned(PAGE_SIZE);
  64static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
  65
 
 
 
 
 
 
 
 
 
 
 
 
  66static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
  67
  68static void __init xen_parse_512gb(void)
  69{
  70	bool val = false;
  71	char *arg;
  72
  73	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
  74	if (!arg)
  75		return;
  76
  77	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
  78	if (!arg)
  79		val = true;
  80	else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val))
  81		return;
  82
  83	xen_512gb_limit = val;
  84}
  85
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  86static void __init xen_del_extra_mem(unsigned long start_pfn,
  87				     unsigned long n_pfns)
  88{
  89	int i;
  90	unsigned long start_r, size_r;
  91
  92	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
  93		start_r = xen_extra_mem[i].start_pfn;
  94		size_r = xen_extra_mem[i].n_pfns;
  95
  96		/* Start of region. */
  97		if (start_r == start_pfn) {
  98			BUG_ON(n_pfns > size_r);
  99			xen_extra_mem[i].start_pfn += n_pfns;
 100			xen_extra_mem[i].n_pfns -= n_pfns;
 101			break;
 102		}
 103		/* End of region. */
 104		if (start_r + size_r == start_pfn + n_pfns) {
 105			BUG_ON(n_pfns > size_r);
 106			xen_extra_mem[i].n_pfns -= n_pfns;
 107			break;
 108		}
 109		/* Mid of region. */
 110		if (start_pfn > start_r && start_pfn < start_r + size_r) {
 111			BUG_ON(start_pfn + n_pfns > start_r + size_r);
 112			xen_extra_mem[i].n_pfns = start_pfn - start_r;
 113			/* Calling memblock_reserve() again is okay. */
 114			xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
 115					  (start_pfn + n_pfns));
 116			break;
 117		}
 118	}
 119	memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
 120}
 121
 122/*
 123 * Called during boot before the p2m list can take entries beyond the
 124 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
 125 * invalid.
 126 */
 127unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
 128{
 129	int i;
 130
 131	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 132		if (pfn >= xen_extra_mem[i].start_pfn &&
 133		    pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
 134			return INVALID_P2M_ENTRY;
 135	}
 136
 137	return IDENTITY_FRAME(pfn);
 138}
 139
 140/*
 141 * Mark all pfns of extra mem as invalid in p2m list.
 142 */
 143void __init xen_inv_extra_mem(void)
 144{
 145	unsigned long pfn, pfn_s, pfn_e;
 146	int i;
 147
 148	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 149		if (!xen_extra_mem[i].n_pfns)
 150			continue;
 151		pfn_s = xen_extra_mem[i].start_pfn;
 152		pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
 153		for (pfn = pfn_s; pfn < pfn_e; pfn++)
 154			set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 155	}
 156}
 157
 158/*
 159 * Finds the next RAM pfn available in the E820 map after min_pfn.
 160 * This function updates min_pfn with the pfn found and returns
 161 * the size of that range or zero if not found.
 162 */
 163static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
 164{
 165	const struct e820_entry *entry = xen_e820_table.entries;
 166	unsigned int i;
 167	unsigned long done = 0;
 168
 169	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 170		unsigned long s_pfn;
 171		unsigned long e_pfn;
 172
 173		if (entry->type != E820_TYPE_RAM)
 174			continue;
 175
 176		e_pfn = PFN_DOWN(entry->addr + entry->size);
 177
 178		/* We only care about E820 after this */
 179		if (e_pfn <= *min_pfn)
 180			continue;
 181
 182		s_pfn = PFN_UP(entry->addr);
 183
 184		/* If min_pfn falls within the E820 entry, we want to start
 185		 * at the min_pfn PFN.
 186		 */
 187		if (s_pfn <= *min_pfn) {
 188			done = e_pfn - *min_pfn;
 189		} else {
 190			done = e_pfn - s_pfn;
 191			*min_pfn = s_pfn;
 192		}
 193		break;
 194	}
 195
 196	return done;
 197}
 198
 199static int __init xen_free_mfn(unsigned long mfn)
 200{
 201	struct xen_memory_reservation reservation = {
 202		.address_bits = 0,
 203		.extent_order = 0,
 204		.domid        = DOMID_SELF
 205	};
 206
 207	set_xen_guest_handle(reservation.extent_start, &mfn);
 208	reservation.nr_extents = 1;
 209
 210	return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
 211}
 212
 213/*
 214 * This releases a chunk of memory and then does the identity map. It's used
 215 * as a fallback if the remapping fails.
 216 */
 217static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
 218						      unsigned long end_pfn)
 219{
 220	unsigned long pfn, end;
 221	int ret;
 222
 223	WARN_ON(start_pfn > end_pfn);
 224
 225	/* Release pages first. */
 226	end = min(end_pfn, ini_nr_pages);
 227	for (pfn = start_pfn; pfn < end; pfn++) {
 228		unsigned long mfn = pfn_to_mfn(pfn);
 229
 230		/* Make sure pfn exists to start with */
 231		if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
 232			continue;
 233
 234		ret = xen_free_mfn(mfn);
 235		WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
 236
 237		if (ret == 1) {
 238			xen_released_pages++;
 239			if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
 240				break;
 241		} else
 242			break;
 243	}
 244
 245	set_phys_range_identity(start_pfn, end_pfn);
 246}
 247
 248/*
 249 * Helper function to update the p2m and m2p tables and kernel mapping.
 250 */
 251static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
 252{
 253	struct mmu_update update = {
 254		.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
 255		.val = pfn
 256	};
 257
 258	/* Update p2m */
 259	if (!set_phys_to_machine(pfn, mfn)) {
 260		WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
 261		     pfn, mfn);
 262		BUG();
 263	}
 264
 265	/* Update m2p */
 266	if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
 267		WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
 268		     mfn, pfn);
 269		BUG();
 270	}
 271
 
 
 
 
 272	if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
 273					 mfn_pte(mfn, PAGE_KERNEL), 0)) {
 274		WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
 275		      mfn, pfn);
 276		BUG();
 277	}
 278}
 279
 280/*
 281 * This function updates the p2m and m2p tables with an identity map from
 282 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
 283 * original allocation at remap_pfn. The information needed for remapping is
 284 * saved in the memory itself to avoid the need for allocating buffers. The
 285 * complete remap information is contained in a list of MFNs each containing
 286 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
 287 * This enables us to preserve the original mfn sequence while doing the
 288 * remapping at a time when the memory management is capable of allocating
 289 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
 290 * its callers.
 291 */
 292static void __init xen_do_set_identity_and_remap_chunk(
 293        unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
 294{
 295	unsigned long buf = (unsigned long)&xen_remap_buf;
 296	unsigned long mfn_save, mfn;
 297	unsigned long ident_pfn_iter, remap_pfn_iter;
 298	unsigned long ident_end_pfn = start_pfn + size;
 299	unsigned long left = size;
 300	unsigned int i, chunk;
 301
 302	WARN_ON(size == 0);
 303
 304	mfn_save = virt_to_mfn((void *)buf);
 305
 306	for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
 307	     ident_pfn_iter < ident_end_pfn;
 308	     ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
 309		chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
 310
 311		/* Map first pfn to xen_remap_buf */
 312		mfn = pfn_to_mfn(ident_pfn_iter);
 313		set_pte_mfn(buf, mfn, PAGE_KERNEL);
 314
 315		/* Save mapping information in page */
 316		xen_remap_buf.next_area_mfn = xen_remap_mfn;
 317		xen_remap_buf.target_pfn = remap_pfn_iter;
 318		xen_remap_buf.size = chunk;
 319		for (i = 0; i < chunk; i++)
 320			xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
 321
 322		/* Put remap buf into list. */
 323		xen_remap_mfn = mfn;
 324
 325		/* Set identity map */
 326		set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
 327
 328		left -= chunk;
 329	}
 330
 331	/* Restore old xen_remap_buf mapping */
 332	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
 333}
 334
 335/*
 336 * This function takes a contiguous pfn range that needs to be identity mapped
 337 * and:
 338 *
 339 *  1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
 340 *  2) Calls the do_ function to actually do the mapping/remapping work.
 341 *
 342 * The goal is to not allocate additional memory but to remap the existing
 343 * pages. In the case of an error the underlying memory is simply released back
 344 * to Xen and not remapped.
 345 */
 346static unsigned long __init xen_set_identity_and_remap_chunk(
 347	unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pfn)
 
 348{
 349	unsigned long pfn;
 350	unsigned long i = 0;
 351	unsigned long n = end_pfn - start_pfn;
 352
 353	if (remap_pfn == 0)
 354		remap_pfn = ini_nr_pages;
 355
 356	while (i < n) {
 357		unsigned long cur_pfn = start_pfn + i;
 358		unsigned long left = n - i;
 359		unsigned long size = left;
 360		unsigned long remap_range_size;
 361
 362		/* Do not remap pages beyond the current allocation */
 363		if (cur_pfn >= ini_nr_pages) {
 364			/* Identity map remaining pages */
 365			set_phys_range_identity(cur_pfn, cur_pfn + size);
 366			break;
 367		}
 368		if (cur_pfn + size > ini_nr_pages)
 369			size = ini_nr_pages - cur_pfn;
 370
 371		remap_range_size = xen_find_pfn_range(&remap_pfn);
 372		if (!remap_range_size) {
 373			pr_warn("Unable to find available pfn range, not remapping identity pages\n");
 374			xen_set_identity_and_release_chunk(cur_pfn,
 375							   cur_pfn + left);
 376			break;
 377		}
 378		/* Adjust size to fit in current e820 RAM region */
 379		if (size > remap_range_size)
 380			size = remap_range_size;
 381
 382		xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
 383
 384		/* Update variables to reflect new mappings. */
 385		i += size;
 386		remap_pfn += size;
 387	}
 388
 389	/*
 390	 * If the PFNs are currently mapped, their VA mappings need to be
 391	 * zapped.
 392	 */
 393	for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
 394		(void)HYPERVISOR_update_va_mapping(
 395			(unsigned long)__va(pfn << PAGE_SHIFT),
 396			native_make_pte(0), 0);
 397
 398	return remap_pfn;
 399}
 400
 401static unsigned long __init xen_count_remap_pages(
 402	unsigned long start_pfn, unsigned long end_pfn,
 403	unsigned long remap_pages)
 404{
 405	if (start_pfn >= ini_nr_pages)
 406		return remap_pages;
 407
 408	return remap_pages + min(end_pfn, ini_nr_pages) - start_pfn;
 409}
 410
 411static unsigned long __init xen_foreach_remap_area(
 412	unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
 413			      unsigned long last_val))
 414{
 415	phys_addr_t start = 0;
 416	unsigned long ret_val = 0;
 417	const struct e820_entry *entry = xen_e820_table.entries;
 418	int i;
 419
 420	/*
 421	 * Combine non-RAM regions and gaps until a RAM region (or the
 422	 * end of the map) is reached, then call the provided function
 423	 * to perform its duty on the non-RAM region.
 424	 *
 425	 * The combined non-RAM regions are rounded to a whole number
 426	 * of pages so any partial pages are accessible via the 1:1
 427	 * mapping.  This is needed for some BIOSes that put (for
 428	 * example) the DMI tables in a reserved region that begins on
 429	 * a non-page boundary.
 430	 */
 431	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 432		phys_addr_t end = entry->addr + entry->size;
 433		if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
 434			unsigned long start_pfn = PFN_DOWN(start);
 435			unsigned long end_pfn = PFN_UP(end);
 436
 437			if (entry->type == E820_TYPE_RAM)
 438				end_pfn = PFN_UP(entry->addr);
 439
 440			if (start_pfn < end_pfn)
 441				ret_val = func(start_pfn, end_pfn, ret_val);
 
 442			start = end;
 443		}
 444	}
 445
 446	return ret_val;
 447}
 448
 449/*
 450 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
 451 * The remap information (which mfn remap to which pfn) is contained in the
 452 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
 453 * This scheme allows to remap the different chunks in arbitrary order while
 454 * the resulting mapping will be independent from the order.
 455 */
 456void __init xen_remap_memory(void)
 457{
 458	unsigned long buf = (unsigned long)&xen_remap_buf;
 459	unsigned long mfn_save, pfn;
 460	unsigned long remapped = 0;
 461	unsigned int i;
 462	unsigned long pfn_s = ~0UL;
 463	unsigned long len = 0;
 464
 465	mfn_save = virt_to_mfn((void *)buf);
 466
 467	while (xen_remap_mfn != INVALID_P2M_ENTRY) {
 468		/* Map the remap information */
 469		set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
 470
 471		BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
 472
 473		pfn = xen_remap_buf.target_pfn;
 474		for (i = 0; i < xen_remap_buf.size; i++) {
 475			xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
 476			remapped++;
 477			pfn++;
 478		}
 479		if (pfn_s == ~0UL || pfn == pfn_s) {
 480			pfn_s = xen_remap_buf.target_pfn;
 481			len += xen_remap_buf.size;
 482		} else if (pfn_s + len == xen_remap_buf.target_pfn) {
 483			len += xen_remap_buf.size;
 484		} else {
 485			xen_del_extra_mem(pfn_s, len);
 486			pfn_s = xen_remap_buf.target_pfn;
 487			len = xen_remap_buf.size;
 488		}
 489		xen_remap_mfn = xen_remap_buf.next_area_mfn;
 490	}
 491
 492	if (pfn_s != ~0UL && len)
 493		xen_del_extra_mem(pfn_s, len);
 494
 495	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
 496
 497	pr_info("Remapped %ld page(s)\n", remapped);
 498
 499	xen_do_remap_nonram();
 500}
 501
 502static unsigned long __init xen_get_pages_limit(void)
 503{
 504	unsigned long limit;
 505
 
 
 
 506	limit = MAXMEM / PAGE_SIZE;
 507	if (!xen_initial_domain() && xen_512gb_limit)
 508		limit = GB(512) / PAGE_SIZE;
 509
 510	return limit;
 511}
 512
 513static unsigned long __init xen_get_max_pages(void)
 514{
 515	unsigned long max_pages, limit;
 516	domid_t domid = DOMID_SELF;
 517	long ret;
 518
 519	limit = xen_get_pages_limit();
 520	max_pages = limit;
 521
 522	/*
 523	 * For the initial domain we use the maximum reservation as
 524	 * the maximum page.
 525	 *
 526	 * For guest domains the current maximum reservation reflects
 527	 * the current maximum rather than the static maximum. In this
 528	 * case the e820 map provided to us will cover the static
 529	 * maximum region.
 530	 */
 531	if (xen_initial_domain()) {
 532		ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
 533		if (ret > 0)
 534			max_pages = ret;
 535	}
 536
 537	return min(max_pages, limit);
 538}
 539
 540static void __init xen_align_and_add_e820_region(phys_addr_t start,
 541						 phys_addr_t size, int type)
 542{
 543	phys_addr_t end = start + size;
 544
 545	/* Align RAM regions to page boundaries. */
 546	if (type == E820_TYPE_RAM) {
 547		start = PAGE_ALIGN(start);
 548		end &= ~((phys_addr_t)PAGE_SIZE - 1);
 549#ifdef CONFIG_MEMORY_HOTPLUG
 550		/*
 551		 * Don't allow adding memory not in E820 map while booting the
 552		 * system. Once the balloon driver is up it will remove that
 553		 * restriction again.
 554		 */
 555		max_mem_size = end;
 556#endif
 557	}
 558
 559	e820__range_add(start, end - start, type);
 560}
 561
 562static void __init xen_ignore_unusable(void)
 563{
 564	struct e820_entry *entry = xen_e820_table.entries;
 565	unsigned int i;
 566
 567	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 568		if (entry->type == E820_TYPE_UNUSABLE)
 569			entry->type = E820_TYPE_RAM;
 570	}
 571}
 572
 573static bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
 574{
 575	struct e820_entry *entry;
 576	unsigned mapcnt;
 577	phys_addr_t end;
 578
 579	if (!size)
 580		return false;
 581
 582	end = start + size;
 583	entry = xen_e820_table.entries;
 584
 585	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
 586		if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
 587		    (entry->addr + entry->size) >= end)
 588			return false;
 589
 590		entry++;
 591	}
 592
 593	return true;
 594}
 595
 596/*
 597 * Find a free area in physical memory not yet reserved and compliant with
 598 * E820 map.
 599 * Used to relocate pre-allocated areas like initrd or p2m list which are in
 600 * conflict with the to be used E820 map.
 601 * In case no area is found, return 0. Otherwise return the physical address
 602 * of the area which is already reserved for convenience.
 603 */
 604phys_addr_t __init xen_find_free_area(phys_addr_t size)
 605{
 606	unsigned mapcnt;
 607	phys_addr_t addr, start;
 608	struct e820_entry *entry = xen_e820_table.entries;
 609
 610	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
 611		if (entry->type != E820_TYPE_RAM || entry->size < size)
 612			continue;
 613		start = entry->addr;
 614		for (addr = start; addr < start + size; addr += PAGE_SIZE) {
 615			if (!memblock_is_reserved(addr))
 616				continue;
 617			start = addr + PAGE_SIZE;
 618			if (start + size > entry->addr + entry->size)
 619				break;
 620		}
 621		if (addr >= start + size) {
 622			memblock_reserve(start, size);
 623			return start;
 624		}
 625	}
 626
 627	return 0;
 628}
 629
 630/*
 631 * Swap a non-RAM E820 map entry with RAM above ini_nr_pages.
 632 * Note that the E820 map is modified accordingly, but the P2M map isn't yet.
 633 * The adaption of the P2M must be deferred until page allocation is possible.
 634 */
 635static void __init xen_e820_swap_entry_with_ram(struct e820_entry *swap_entry)
 636{
 637	struct e820_entry *entry;
 638	unsigned int mapcnt;
 639	phys_addr_t mem_end = PFN_PHYS(ini_nr_pages);
 640	phys_addr_t swap_addr, swap_size, entry_end;
 641
 642	swap_addr = PAGE_ALIGN_DOWN(swap_entry->addr);
 643	swap_size = PAGE_ALIGN(swap_entry->addr - swap_addr + swap_entry->size);
 644	entry = xen_e820_table.entries;
 645
 646	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
 647		entry_end = entry->addr + entry->size;
 648		if (entry->type == E820_TYPE_RAM && entry->size >= swap_size &&
 649		    entry_end - swap_size >= mem_end) {
 650			/* Reduce RAM entry by needed space (whole pages). */
 651			entry->size -= swap_size;
 652
 653			/* Add new entry at the end of E820 map. */
 654			entry = xen_e820_table.entries +
 655				xen_e820_table.nr_entries;
 656			xen_e820_table.nr_entries++;
 657
 658			/* Fill new entry (keep size and page offset). */
 659			entry->type = swap_entry->type;
 660			entry->addr = entry_end - swap_size +
 661				      swap_addr - swap_entry->addr;
 662			entry->size = swap_entry->size;
 663
 664			/* Convert old entry to RAM, align to pages. */
 665			swap_entry->type = E820_TYPE_RAM;
 666			swap_entry->addr = swap_addr;
 667			swap_entry->size = swap_size;
 668
 669			/* Remember PFN<->MFN relation for P2M update. */
 670			xen_add_remap_nonram(swap_addr, entry_end - swap_size,
 671					     swap_size);
 672
 673			/* Order E820 table and merge entries. */
 674			e820__update_table(&xen_e820_table);
 675
 676			return;
 677		}
 678
 679		entry++;
 680	}
 681
 682	xen_raw_console_write("No suitable area found for required E820 entry remapping action\n");
 683	BUG();
 684}
 685
 686/*
 687 * Look for non-RAM memory types in a specific guest physical area and move
 688 * those away if possible (ACPI NVS only for now).
 689 */
 690static void __init xen_e820_resolve_conflicts(phys_addr_t start,
 691					      phys_addr_t size)
 692{
 693	struct e820_entry *entry;
 694	unsigned int mapcnt;
 695	phys_addr_t end;
 696
 697	if (!size)
 698		return;
 699
 700	end = start + size;
 701	entry = xen_e820_table.entries;
 702
 703	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
 704		if (entry->addr >= end)
 705			return;
 706
 707		if (entry->addr + entry->size > start &&
 708		    entry->type == E820_TYPE_NVS)
 709			xen_e820_swap_entry_with_ram(entry);
 710
 711		entry++;
 712	}
 713}
 714
 715/*
 716 * Check for an area in physical memory to be usable for non-movable purposes.
 717 * An area is considered to usable if the used E820 map lists it to be RAM or
 718 * some other type which can be moved to higher PFNs while keeping the MFNs.
 719 * In case the area is not usable, crash the system with an error message.
 720 */
 721void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size,
 722				   const char *component)
 723{
 724	xen_e820_resolve_conflicts(start, size);
 725
 726	if (!xen_is_e820_reserved(start, size))
 727		return;
 728
 729	xen_raw_console_write("Xen hypervisor allocated ");
 730	xen_raw_console_write(component);
 731	xen_raw_console_write(" memory conflicts with E820 map\n");
 732	BUG();
 733}
 734
 735/*
 736 * Like memcpy, but with physical addresses for dest and src.
 737 */
 738static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
 739				   phys_addr_t n)
 740{
 741	phys_addr_t dest_off, src_off, dest_len, src_len, len;
 742	void *from, *to;
 743
 744	while (n) {
 745		dest_off = dest & ~PAGE_MASK;
 746		src_off = src & ~PAGE_MASK;
 747		dest_len = n;
 748		if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
 749			dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
 750		src_len = n;
 751		if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
 752			src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
 753		len = min(dest_len, src_len);
 754		to = early_memremap(dest - dest_off, dest_len + dest_off);
 755		from = early_memremap(src - src_off, src_len + src_off);
 756		memcpy(to, from, len);
 757		early_memunmap(to, dest_len + dest_off);
 758		early_memunmap(from, src_len + src_off);
 759		n -= len;
 760		dest += len;
 761		src += len;
 762	}
 763}
 764
 765/*
 766 * Reserve Xen mfn_list.
 767 */
 768static void __init xen_reserve_xen_mfnlist(void)
 769{
 770	phys_addr_t start, size;
 771
 772	if (xen_start_info->mfn_list >= __START_KERNEL_map) {
 773		start = __pa(xen_start_info->mfn_list);
 774		size = PFN_ALIGN(xen_start_info->nr_pages *
 775				 sizeof(unsigned long));
 776	} else {
 777		start = PFN_PHYS(xen_start_info->first_p2m_pfn);
 778		size = PFN_PHYS(xen_start_info->nr_p2m_frames);
 779	}
 780
 781	memblock_reserve(start, size);
 782	if (!xen_is_e820_reserved(start, size))
 783		return;
 784
 
 
 
 
 
 
 
 
 785	xen_relocate_p2m();
 786	memblock_phys_free(start, size);
 
 787}
 788
 789/**
 790 * xen_memory_setup - Hook for machine specific memory setup.
 791 **/
 792char * __init xen_memory_setup(void)
 793{
 794	unsigned long pfn_s, n_pfns;
 795	phys_addr_t mem_end, addr, size, chunk_size;
 796	u32 type;
 797	int rc;
 798	struct xen_memory_map memmap;
 799	unsigned long max_pages;
 800	unsigned long extra_pages = 0;
 801	unsigned long maxmem_pages;
 802	int i;
 803	int op;
 804
 805	xen_parse_512gb();
 806	ini_nr_pages = min(xen_get_pages_limit(), xen_start_info->nr_pages);
 807	mem_end = PFN_PHYS(ini_nr_pages);
 
 808
 809	memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
 810	set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
 811
 812#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
 813	xen_saved_max_mem_size = max_mem_size;
 814#endif
 815
 816	op = xen_initial_domain() ?
 817		XENMEM_machine_memory_map :
 818		XENMEM_memory_map;
 819	rc = HYPERVISOR_memory_op(op, &memmap);
 820	if (rc == -ENOSYS) {
 821		BUG_ON(xen_initial_domain());
 822		memmap.nr_entries = 1;
 823		xen_e820_table.entries[0].addr = 0ULL;
 824		xen_e820_table.entries[0].size = mem_end;
 825		/* 8MB slack (to balance backend allocations). */
 826		xen_e820_table.entries[0].size += 8ULL << 20;
 827		xen_e820_table.entries[0].type = E820_TYPE_RAM;
 828		rc = 0;
 829	}
 830	BUG_ON(rc);
 831	BUG_ON(memmap.nr_entries == 0);
 832	xen_e820_table.nr_entries = memmap.nr_entries;
 833
 834	if (xen_initial_domain()) {
 835		/*
 836		 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
 837		 * regions, so if we're using the machine memory map leave the
 838		 * region as RAM as it is in the pseudo-physical map.
 839		 *
 840		 * UNUSABLE regions in domUs are not handled and will need
 841		 * a patch in the future.
 842		 */
 843		xen_ignore_unusable();
 844
 845#ifdef CONFIG_ISCSI_IBFT_FIND
 846		/* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */
 847		xen_e820_table.entries[xen_e820_table.nr_entries].addr = IBFT_START;
 848		xen_e820_table.entries[xen_e820_table.nr_entries].size = IBFT_END - IBFT_START;
 849		xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED;
 850		xen_e820_table.nr_entries++;
 851#endif
 852	}
 853
 854	/* Make sure the Xen-supplied memory map is well-ordered. */
 855	e820__update_table(&xen_e820_table);
 856
 857	/*
 858	 * Check whether the kernel itself conflicts with the target E820 map.
 859	 * Failing now is better than running into weird problems later due
 860	 * to relocating (and even reusing) pages with kernel text or data.
 861	 */
 862	xen_chk_is_e820_usable(__pa_symbol(_text),
 863			       __pa_symbol(_end) - __pa_symbol(_text),
 864			       "kernel");
 865
 866	/*
 867	 * Check for a conflict of the xen_start_info memory with the target
 868	 * E820 map.
 869	 */
 870	xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info),
 871			       "xen_start_info");
 872
 873	/*
 874	 * Check for a conflict of the hypervisor supplied page tables with
 875	 * the target E820 map.
 876	 */
 877	xen_pt_check_e820();
 878
 879	max_pages = xen_get_max_pages();
 880
 881	/* How many extra pages do we need due to remapping? */
 882	max_pages += xen_foreach_remap_area(xen_count_remap_pages);
 883
 884	if (max_pages > ini_nr_pages)
 885		extra_pages += max_pages - ini_nr_pages;
 886
 887	/*
 888	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
 889	 * factor the base size.
 
 
 
 890	 *
 891	 * Make sure we have no memory above max_pages, as this area
 892	 * isn't handled by the p2m management.
 
 
 
 
 893	 */
 894	maxmem_pages = EXTRA_MEM_RATIO * min(ini_nr_pages, PFN_DOWN(MAXMEM));
 895	extra_pages = min3(maxmem_pages, extra_pages, max_pages - ini_nr_pages);
 896	i = 0;
 897	addr = xen_e820_table.entries[0].addr;
 898	size = xen_e820_table.entries[0].size;
 899	while (i < xen_e820_table.nr_entries) {
 900		bool discard = false;
 901
 902		chunk_size = size;
 903		type = xen_e820_table.entries[i].type;
 904
 905		if (type == E820_TYPE_RESERVED)
 906			xen_pv_pci_possible = true;
 907
 908		if (type == E820_TYPE_RAM) {
 909			if (addr < mem_end) {
 910				chunk_size = min(size, mem_end - addr);
 911			} else if (extra_pages) {
 912				chunk_size = min(size, PFN_PHYS(extra_pages));
 913				pfn_s = PFN_UP(addr);
 914				n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
 915				extra_pages -= n_pfns;
 916				xen_add_extra_mem(pfn_s, n_pfns);
 917				xen_max_p2m_pfn = pfn_s + n_pfns;
 918			} else
 919				discard = true;
 920		}
 921
 922		if (!discard)
 923			xen_align_and_add_e820_region(addr, chunk_size, type);
 924
 925		addr += chunk_size;
 926		size -= chunk_size;
 927		if (size == 0) {
 928			i++;
 929			if (i < xen_e820_table.nr_entries) {
 930				addr = xen_e820_table.entries[i].addr;
 931				size = xen_e820_table.entries[i].size;
 932			}
 933		}
 934	}
 935
 936	/*
 937	 * Set the rest as identity mapped, in case PCI BARs are
 938	 * located here.
 939	 */
 940	set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
 941
 942	/*
 943	 * In domU, the ISA region is normal, usable memory, but we
 944	 * reserve ISA memory anyway because too many things poke
 945	 * about in there.
 946	 */
 947	e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
 948
 949	e820__update_table(e820_table);
 950
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 951	xen_reserve_xen_mfnlist();
 952
 953	/* Check for a conflict of the initrd with the target E820 map. */
 954	if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
 955				 boot_params.hdr.ramdisk_size)) {
 956		phys_addr_t new_area, start, size;
 957
 958		new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
 959		if (!new_area) {
 960			xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
 961			BUG();
 962		}
 963
 964		start = boot_params.hdr.ramdisk_image;
 965		size = boot_params.hdr.ramdisk_size;
 966		xen_phys_memcpy(new_area, start, size);
 967		pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
 968			start, start + size, new_area, new_area + size);
 969		memblock_phys_free(start, size);
 970		boot_params.hdr.ramdisk_image = new_area;
 971		boot_params.ext_ramdisk_image = new_area >> 32;
 972	}
 973
 974	/*
 975	 * Set identity map on non-RAM pages and prepare remapping the
 976	 * underlying RAM.
 977	 */
 978	xen_foreach_remap_area(xen_set_identity_and_remap_chunk);
 979
 980	pr_info("Released %ld page(s)\n", xen_released_pages);
 981
 982	return "Xen";
 983}
 984
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 985static int register_callback(unsigned type, const void *func)
 986{
 987	struct callback_register callback = {
 988		.type = type,
 989		.address = XEN_CALLBACK(__KERNEL_CS, func),
 990		.flags = CALLBACKF_mask_events,
 991	};
 992
 993	return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
 994}
 995
 996void xen_enable_sysenter(void)
 997{
 998	if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) &&
 999	    register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat))
1000		setup_clear_cpu_cap(X86_FEATURE_SYSENTER32);
 
 
 
 
 
 
 
 
 
 
 
 
1001}
1002
1003void xen_enable_syscall(void)
1004{
 
1005	int ret;
1006
1007	ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64);
1008	if (ret != 0) {
1009		printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
1010		/* Pretty fatal; 64-bit userspace has no other
1011		   mechanism for syscalls. */
1012	}
1013
1014	if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) &&
1015	    register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat))
1016		setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
 
 
 
 
1017}
1018
1019static void __init xen_pvmmu_arch_setup(void)
1020{
 
1021	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1022
1023	if (register_callback(CALLBACKTYPE_event,
1024			      xen_asm_exc_xen_hypervisor_callback) ||
 
 
1025	    register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1026		BUG();
1027
1028	xen_enable_sysenter();
1029	xen_enable_syscall();
1030}
1031
1032/* This function is not called for HVM domains */
1033void __init xen_arch_setup(void)
1034{
1035	xen_panic_handler_init();
1036	xen_pvmmu_arch_setup();
1037
1038#ifdef CONFIG_ACPI
1039	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1040		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1041		disable_acpi();
1042	}
1043#endif
1044
1045	memcpy(boot_command_line, xen_start_info->cmd_line,
1046	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1047	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1048
1049	/* Set up idle, making sure it calls safe_halt() pvop */
1050	disable_cpuidle();
1051	disable_cpufreq();
1052	WARN_ON(xen_set_default_idle());
 
1053#ifdef CONFIG_NUMA
1054	numa_off = 1;
1055#endif
1056}
v4.17
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Machine specific setup for xen
   4 *
   5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
   6 */
   7
   8#include <linux/init.h>
 
   9#include <linux/sched.h>
 
  10#include <linux/mm.h>
  11#include <linux/pm.h>
  12#include <linux/memblock.h>
  13#include <linux/cpuidle.h>
  14#include <linux/cpufreq.h>
 
 
  15
  16#include <asm/elf.h>
  17#include <asm/vdso.h>
  18#include <asm/e820/api.h>
  19#include <asm/setup.h>
  20#include <asm/acpi.h>
  21#include <asm/numa.h>
 
  22#include <asm/xen/hypervisor.h>
  23#include <asm/xen/hypercall.h>
  24
  25#include <xen/xen.h>
  26#include <xen/page.h>
  27#include <xen/interface/callback.h>
  28#include <xen/interface/memory.h>
  29#include <xen/interface/physdev.h>
  30#include <xen/features.h>
  31#include <xen/hvc-console.h>
  32#include "xen-ops.h"
  33#include "vdso.h"
  34#include "mmu.h"
  35
  36#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
  37
  38/* Amount of extra memory space we add to the e820 ranges */
  39struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  40
  41/* Number of pages released from the initial allocation. */
  42unsigned long xen_released_pages;
  43
 
 
 
  44/* E820 map used during setting up memory. */
  45static struct e820_table xen_e820_table __initdata;
  46
 
 
 
  47/*
  48 * Buffer used to remap identity mapped pages. We only need the virtual space.
  49 * The physical page behind this address is remapped as needed to different
  50 * buffer pages.
  51 */
  52#define REMAP_SIZE	(P2M_PER_PAGE - 3)
  53static struct {
  54	unsigned long	next_area_mfn;
  55	unsigned long	target_pfn;
  56	unsigned long	size;
  57	unsigned long	mfns[REMAP_SIZE];
  58} xen_remap_buf __initdata __aligned(PAGE_SIZE);
  59static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
  60
  61/* 
  62 * The maximum amount of extra memory compared to the base size.  The
  63 * main scaling factor is the size of struct page.  At extreme ratios
  64 * of base:extra, all the base memory can be filled with page
  65 * structures for the extra memory, leaving no space for anything
  66 * else.
  67 * 
  68 * 10x seems like a reasonable balance between scaling flexibility and
  69 * leaving a practically usable system.
  70 */
  71#define EXTRA_MEM_RATIO		(10)
  72
  73static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
  74
  75static void __init xen_parse_512gb(void)
  76{
  77	bool val = false;
  78	char *arg;
  79
  80	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
  81	if (!arg)
  82		return;
  83
  84	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
  85	if (!arg)
  86		val = true;
  87	else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
  88		return;
  89
  90	xen_512gb_limit = val;
  91}
  92
  93static void __init xen_add_extra_mem(unsigned long start_pfn,
  94				     unsigned long n_pfns)
  95{
  96	int i;
  97
  98	/*
  99	 * No need to check for zero size, should happen rarely and will only
 100	 * write a new entry regarded to be unused due to zero size.
 101	 */
 102	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 103		/* Add new region. */
 104		if (xen_extra_mem[i].n_pfns == 0) {
 105			xen_extra_mem[i].start_pfn = start_pfn;
 106			xen_extra_mem[i].n_pfns = n_pfns;
 107			break;
 108		}
 109		/* Append to existing region. */
 110		if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
 111		    start_pfn) {
 112			xen_extra_mem[i].n_pfns += n_pfns;
 113			break;
 114		}
 115	}
 116	if (i == XEN_EXTRA_MEM_MAX_REGIONS)
 117		printk(KERN_WARNING "Warning: not enough extra memory regions\n");
 118
 119	memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
 120}
 121
 122static void __init xen_del_extra_mem(unsigned long start_pfn,
 123				     unsigned long n_pfns)
 124{
 125	int i;
 126	unsigned long start_r, size_r;
 127
 128	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 129		start_r = xen_extra_mem[i].start_pfn;
 130		size_r = xen_extra_mem[i].n_pfns;
 131
 132		/* Start of region. */
 133		if (start_r == start_pfn) {
 134			BUG_ON(n_pfns > size_r);
 135			xen_extra_mem[i].start_pfn += n_pfns;
 136			xen_extra_mem[i].n_pfns -= n_pfns;
 137			break;
 138		}
 139		/* End of region. */
 140		if (start_r + size_r == start_pfn + n_pfns) {
 141			BUG_ON(n_pfns > size_r);
 142			xen_extra_mem[i].n_pfns -= n_pfns;
 143			break;
 144		}
 145		/* Mid of region. */
 146		if (start_pfn > start_r && start_pfn < start_r + size_r) {
 147			BUG_ON(start_pfn + n_pfns > start_r + size_r);
 148			xen_extra_mem[i].n_pfns = start_pfn - start_r;
 149			/* Calling memblock_reserve() again is okay. */
 150			xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
 151					  (start_pfn + n_pfns));
 152			break;
 153		}
 154	}
 155	memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
 156}
 157
 158/*
 159 * Called during boot before the p2m list can take entries beyond the
 160 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
 161 * invalid.
 162 */
 163unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
 164{
 165	int i;
 166
 167	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 168		if (pfn >= xen_extra_mem[i].start_pfn &&
 169		    pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
 170			return INVALID_P2M_ENTRY;
 171	}
 172
 173	return IDENTITY_FRAME(pfn);
 174}
 175
 176/*
 177 * Mark all pfns of extra mem as invalid in p2m list.
 178 */
 179void __init xen_inv_extra_mem(void)
 180{
 181	unsigned long pfn, pfn_s, pfn_e;
 182	int i;
 183
 184	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
 185		if (!xen_extra_mem[i].n_pfns)
 186			continue;
 187		pfn_s = xen_extra_mem[i].start_pfn;
 188		pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
 189		for (pfn = pfn_s; pfn < pfn_e; pfn++)
 190			set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 191	}
 192}
 193
 194/*
 195 * Finds the next RAM pfn available in the E820 map after min_pfn.
 196 * This function updates min_pfn with the pfn found and returns
 197 * the size of that range or zero if not found.
 198 */
 199static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
 200{
 201	const struct e820_entry *entry = xen_e820_table.entries;
 202	unsigned int i;
 203	unsigned long done = 0;
 204
 205	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 206		unsigned long s_pfn;
 207		unsigned long e_pfn;
 208
 209		if (entry->type != E820_TYPE_RAM)
 210			continue;
 211
 212		e_pfn = PFN_DOWN(entry->addr + entry->size);
 213
 214		/* We only care about E820 after this */
 215		if (e_pfn <= *min_pfn)
 216			continue;
 217
 218		s_pfn = PFN_UP(entry->addr);
 219
 220		/* If min_pfn falls within the E820 entry, we want to start
 221		 * at the min_pfn PFN.
 222		 */
 223		if (s_pfn <= *min_pfn) {
 224			done = e_pfn - *min_pfn;
 225		} else {
 226			done = e_pfn - s_pfn;
 227			*min_pfn = s_pfn;
 228		}
 229		break;
 230	}
 231
 232	return done;
 233}
 234
 235static int __init xen_free_mfn(unsigned long mfn)
 236{
 237	struct xen_memory_reservation reservation = {
 238		.address_bits = 0,
 239		.extent_order = 0,
 240		.domid        = DOMID_SELF
 241	};
 242
 243	set_xen_guest_handle(reservation.extent_start, &mfn);
 244	reservation.nr_extents = 1;
 245
 246	return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
 247}
 248
 249/*
 250 * This releases a chunk of memory and then does the identity map. It's used
 251 * as a fallback if the remapping fails.
 252 */
 253static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
 254			unsigned long end_pfn, unsigned long nr_pages)
 255{
 256	unsigned long pfn, end;
 257	int ret;
 258
 259	WARN_ON(start_pfn > end_pfn);
 260
 261	/* Release pages first. */
 262	end = min(end_pfn, nr_pages);
 263	for (pfn = start_pfn; pfn < end; pfn++) {
 264		unsigned long mfn = pfn_to_mfn(pfn);
 265
 266		/* Make sure pfn exists to start with */
 267		if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
 268			continue;
 269
 270		ret = xen_free_mfn(mfn);
 271		WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
 272
 273		if (ret == 1) {
 274			xen_released_pages++;
 275			if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
 276				break;
 277		} else
 278			break;
 279	}
 280
 281	set_phys_range_identity(start_pfn, end_pfn);
 282}
 283
 284/*
 285 * Helper function to update the p2m and m2p tables and kernel mapping.
 286 */
 287static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
 288{
 289	struct mmu_update update = {
 290		.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
 291		.val = pfn
 292	};
 293
 294	/* Update p2m */
 295	if (!set_phys_to_machine(pfn, mfn)) {
 296		WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
 297		     pfn, mfn);
 298		BUG();
 299	}
 300
 301	/* Update m2p */
 302	if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
 303		WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
 304		     mfn, pfn);
 305		BUG();
 306	}
 307
 308	/* Update kernel mapping, but not for highmem. */
 309	if (pfn >= PFN_UP(__pa(high_memory - 1)))
 310		return;
 311
 312	if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
 313					 mfn_pte(mfn, PAGE_KERNEL), 0)) {
 314		WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
 315		      mfn, pfn);
 316		BUG();
 317	}
 318}
 319
 320/*
 321 * This function updates the p2m and m2p tables with an identity map from
 322 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
 323 * original allocation at remap_pfn. The information needed for remapping is
 324 * saved in the memory itself to avoid the need for allocating buffers. The
 325 * complete remap information is contained in a list of MFNs each containing
 326 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
 327 * This enables us to preserve the original mfn sequence while doing the
 328 * remapping at a time when the memory management is capable of allocating
 329 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
 330 * its callers.
 331 */
 332static void __init xen_do_set_identity_and_remap_chunk(
 333        unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
 334{
 335	unsigned long buf = (unsigned long)&xen_remap_buf;
 336	unsigned long mfn_save, mfn;
 337	unsigned long ident_pfn_iter, remap_pfn_iter;
 338	unsigned long ident_end_pfn = start_pfn + size;
 339	unsigned long left = size;
 340	unsigned int i, chunk;
 341
 342	WARN_ON(size == 0);
 343
 344	mfn_save = virt_to_mfn(buf);
 345
 346	for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
 347	     ident_pfn_iter < ident_end_pfn;
 348	     ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
 349		chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
 350
 351		/* Map first pfn to xen_remap_buf */
 352		mfn = pfn_to_mfn(ident_pfn_iter);
 353		set_pte_mfn(buf, mfn, PAGE_KERNEL);
 354
 355		/* Save mapping information in page */
 356		xen_remap_buf.next_area_mfn = xen_remap_mfn;
 357		xen_remap_buf.target_pfn = remap_pfn_iter;
 358		xen_remap_buf.size = chunk;
 359		for (i = 0; i < chunk; i++)
 360			xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
 361
 362		/* Put remap buf into list. */
 363		xen_remap_mfn = mfn;
 364
 365		/* Set identity map */
 366		set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
 367
 368		left -= chunk;
 369	}
 370
 371	/* Restore old xen_remap_buf mapping */
 372	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
 373}
 374
 375/*
 376 * This function takes a contiguous pfn range that needs to be identity mapped
 377 * and:
 378 *
 379 *  1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
 380 *  2) Calls the do_ function to actually do the mapping/remapping work.
 381 *
 382 * The goal is to not allocate additional memory but to remap the existing
 383 * pages. In the case of an error the underlying memory is simply released back
 384 * to Xen and not remapped.
 385 */
 386static unsigned long __init xen_set_identity_and_remap_chunk(
 387	unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
 388	unsigned long remap_pfn)
 389{
 390	unsigned long pfn;
 391	unsigned long i = 0;
 392	unsigned long n = end_pfn - start_pfn;
 393
 394	if (remap_pfn == 0)
 395		remap_pfn = nr_pages;
 396
 397	while (i < n) {
 398		unsigned long cur_pfn = start_pfn + i;
 399		unsigned long left = n - i;
 400		unsigned long size = left;
 401		unsigned long remap_range_size;
 402
 403		/* Do not remap pages beyond the current allocation */
 404		if (cur_pfn >= nr_pages) {
 405			/* Identity map remaining pages */
 406			set_phys_range_identity(cur_pfn, cur_pfn + size);
 407			break;
 408		}
 409		if (cur_pfn + size > nr_pages)
 410			size = nr_pages - cur_pfn;
 411
 412		remap_range_size = xen_find_pfn_range(&remap_pfn);
 413		if (!remap_range_size) {
 414			pr_warning("Unable to find available pfn range, not remapping identity pages\n");
 415			xen_set_identity_and_release_chunk(cur_pfn,
 416						cur_pfn + left, nr_pages);
 417			break;
 418		}
 419		/* Adjust size to fit in current e820 RAM region */
 420		if (size > remap_range_size)
 421			size = remap_range_size;
 422
 423		xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
 424
 425		/* Update variables to reflect new mappings. */
 426		i += size;
 427		remap_pfn += size;
 428	}
 429
 430	/*
 431	 * If the PFNs are currently mapped, the VA mapping also needs
 432	 * to be updated to be 1:1.
 433	 */
 434	for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
 435		(void)HYPERVISOR_update_va_mapping(
 436			(unsigned long)__va(pfn << PAGE_SHIFT),
 437			mfn_pte(pfn, PAGE_KERNEL_IO), 0);
 438
 439	return remap_pfn;
 440}
 441
 442static unsigned long __init xen_count_remap_pages(
 443	unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
 444	unsigned long remap_pages)
 445{
 446	if (start_pfn >= nr_pages)
 447		return remap_pages;
 448
 449	return remap_pages + min(end_pfn, nr_pages) - start_pfn;
 450}
 451
 452static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
 453	unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
 454			      unsigned long nr_pages, unsigned long last_val))
 455{
 456	phys_addr_t start = 0;
 457	unsigned long ret_val = 0;
 458	const struct e820_entry *entry = xen_e820_table.entries;
 459	int i;
 460
 461	/*
 462	 * Combine non-RAM regions and gaps until a RAM region (or the
 463	 * end of the map) is reached, then call the provided function
 464	 * to perform its duty on the non-RAM region.
 465	 *
 466	 * The combined non-RAM regions are rounded to a whole number
 467	 * of pages so any partial pages are accessible via the 1:1
 468	 * mapping.  This is needed for some BIOSes that put (for
 469	 * example) the DMI tables in a reserved region that begins on
 470	 * a non-page boundary.
 471	 */
 472	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 473		phys_addr_t end = entry->addr + entry->size;
 474		if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
 475			unsigned long start_pfn = PFN_DOWN(start);
 476			unsigned long end_pfn = PFN_UP(end);
 477
 478			if (entry->type == E820_TYPE_RAM)
 479				end_pfn = PFN_UP(entry->addr);
 480
 481			if (start_pfn < end_pfn)
 482				ret_val = func(start_pfn, end_pfn, nr_pages,
 483					       ret_val);
 484			start = end;
 485		}
 486	}
 487
 488	return ret_val;
 489}
 490
 491/*
 492 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
 493 * The remap information (which mfn remap to which pfn) is contained in the
 494 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
 495 * This scheme allows to remap the different chunks in arbitrary order while
 496 * the resulting mapping will be independant from the order.
 497 */
 498void __init xen_remap_memory(void)
 499{
 500	unsigned long buf = (unsigned long)&xen_remap_buf;
 501	unsigned long mfn_save, pfn;
 502	unsigned long remapped = 0;
 503	unsigned int i;
 504	unsigned long pfn_s = ~0UL;
 505	unsigned long len = 0;
 506
 507	mfn_save = virt_to_mfn(buf);
 508
 509	while (xen_remap_mfn != INVALID_P2M_ENTRY) {
 510		/* Map the remap information */
 511		set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
 512
 513		BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
 514
 515		pfn = xen_remap_buf.target_pfn;
 516		for (i = 0; i < xen_remap_buf.size; i++) {
 517			xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
 518			remapped++;
 519			pfn++;
 520		}
 521		if (pfn_s == ~0UL || pfn == pfn_s) {
 522			pfn_s = xen_remap_buf.target_pfn;
 523			len += xen_remap_buf.size;
 524		} else if (pfn_s + len == xen_remap_buf.target_pfn) {
 525			len += xen_remap_buf.size;
 526		} else {
 527			xen_del_extra_mem(pfn_s, len);
 528			pfn_s = xen_remap_buf.target_pfn;
 529			len = xen_remap_buf.size;
 530		}
 531		xen_remap_mfn = xen_remap_buf.next_area_mfn;
 532	}
 533
 534	if (pfn_s != ~0UL && len)
 535		xen_del_extra_mem(pfn_s, len);
 536
 537	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
 538
 539	pr_info("Remapped %ld page(s)\n", remapped);
 
 
 540}
 541
 542static unsigned long __init xen_get_pages_limit(void)
 543{
 544	unsigned long limit;
 545
 546#ifdef CONFIG_X86_32
 547	limit = GB(64) / PAGE_SIZE;
 548#else
 549	limit = MAXMEM / PAGE_SIZE;
 550	if (!xen_initial_domain() && xen_512gb_limit)
 551		limit = GB(512) / PAGE_SIZE;
 552#endif
 553	return limit;
 554}
 555
 556static unsigned long __init xen_get_max_pages(void)
 557{
 558	unsigned long max_pages, limit;
 559	domid_t domid = DOMID_SELF;
 560	long ret;
 561
 562	limit = xen_get_pages_limit();
 563	max_pages = limit;
 564
 565	/*
 566	 * For the initial domain we use the maximum reservation as
 567	 * the maximum page.
 568	 *
 569	 * For guest domains the current maximum reservation reflects
 570	 * the current maximum rather than the static maximum. In this
 571	 * case the e820 map provided to us will cover the static
 572	 * maximum region.
 573	 */
 574	if (xen_initial_domain()) {
 575		ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
 576		if (ret > 0)
 577			max_pages = ret;
 578	}
 579
 580	return min(max_pages, limit);
 581}
 582
 583static void __init xen_align_and_add_e820_region(phys_addr_t start,
 584						 phys_addr_t size, int type)
 585{
 586	phys_addr_t end = start + size;
 587
 588	/* Align RAM regions to page boundaries. */
 589	if (type == E820_TYPE_RAM) {
 590		start = PAGE_ALIGN(start);
 591		end &= ~((phys_addr_t)PAGE_SIZE - 1);
 
 
 
 
 
 
 
 
 592	}
 593
 594	e820__range_add(start, end - start, type);
 595}
 596
 597static void __init xen_ignore_unusable(void)
 598{
 599	struct e820_entry *entry = xen_e820_table.entries;
 600	unsigned int i;
 601
 602	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
 603		if (entry->type == E820_TYPE_UNUSABLE)
 604			entry->type = E820_TYPE_RAM;
 605	}
 606}
 607
 608bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
 609{
 610	struct e820_entry *entry;
 611	unsigned mapcnt;
 612	phys_addr_t end;
 613
 614	if (!size)
 615		return false;
 616
 617	end = start + size;
 618	entry = xen_e820_table.entries;
 619
 620	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
 621		if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
 622		    (entry->addr + entry->size) >= end)
 623			return false;
 624
 625		entry++;
 626	}
 627
 628	return true;
 629}
 630
 631/*
 632 * Find a free area in physical memory not yet reserved and compliant with
 633 * E820 map.
 634 * Used to relocate pre-allocated areas like initrd or p2m list which are in
 635 * conflict with the to be used E820 map.
 636 * In case no area is found, return 0. Otherwise return the physical address
 637 * of the area which is already reserved for convenience.
 638 */
 639phys_addr_t __init xen_find_free_area(phys_addr_t size)
 640{
 641	unsigned mapcnt;
 642	phys_addr_t addr, start;
 643	struct e820_entry *entry = xen_e820_table.entries;
 644
 645	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
 646		if (entry->type != E820_TYPE_RAM || entry->size < size)
 647			continue;
 648		start = entry->addr;
 649		for (addr = start; addr < start + size; addr += PAGE_SIZE) {
 650			if (!memblock_is_reserved(addr))
 651				continue;
 652			start = addr + PAGE_SIZE;
 653			if (start + size > entry->addr + entry->size)
 654				break;
 655		}
 656		if (addr >= start + size) {
 657			memblock_reserve(start, size);
 658			return start;
 659		}
 660	}
 661
 662	return 0;
 663}
 664
 665/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 666 * Like memcpy, but with physical addresses for dest and src.
 667 */
 668static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
 669				   phys_addr_t n)
 670{
 671	phys_addr_t dest_off, src_off, dest_len, src_len, len;
 672	void *from, *to;
 673
 674	while (n) {
 675		dest_off = dest & ~PAGE_MASK;
 676		src_off = src & ~PAGE_MASK;
 677		dest_len = n;
 678		if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
 679			dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
 680		src_len = n;
 681		if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
 682			src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
 683		len = min(dest_len, src_len);
 684		to = early_memremap(dest - dest_off, dest_len + dest_off);
 685		from = early_memremap(src - src_off, src_len + src_off);
 686		memcpy(to, from, len);
 687		early_memunmap(to, dest_len + dest_off);
 688		early_memunmap(from, src_len + src_off);
 689		n -= len;
 690		dest += len;
 691		src += len;
 692	}
 693}
 694
 695/*
 696 * Reserve Xen mfn_list.
 697 */
 698static void __init xen_reserve_xen_mfnlist(void)
 699{
 700	phys_addr_t start, size;
 701
 702	if (xen_start_info->mfn_list >= __START_KERNEL_map) {
 703		start = __pa(xen_start_info->mfn_list);
 704		size = PFN_ALIGN(xen_start_info->nr_pages *
 705				 sizeof(unsigned long));
 706	} else {
 707		start = PFN_PHYS(xen_start_info->first_p2m_pfn);
 708		size = PFN_PHYS(xen_start_info->nr_p2m_frames);
 709	}
 710
 711	memblock_reserve(start, size);
 712	if (!xen_is_e820_reserved(start, size))
 713		return;
 714
 715#ifdef CONFIG_X86_32
 716	/*
 717	 * Relocating the p2m on 32 bit system to an arbitrary virtual address
 718	 * is not supported, so just give up.
 719	 */
 720	xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
 721	BUG();
 722#else
 723	xen_relocate_p2m();
 724	memblock_free(start, size);
 725#endif
 726}
 727
 728/**
 729 * machine_specific_memory_setup - Hook for machine specific memory setup.
 730 **/
 731char * __init xen_memory_setup(void)
 732{
 733	unsigned long max_pfn, pfn_s, n_pfns;
 734	phys_addr_t mem_end, addr, size, chunk_size;
 735	u32 type;
 736	int rc;
 737	struct xen_memory_map memmap;
 738	unsigned long max_pages;
 739	unsigned long extra_pages = 0;
 
 740	int i;
 741	int op;
 742
 743	xen_parse_512gb();
 744	max_pfn = xen_get_pages_limit();
 745	max_pfn = min(max_pfn, xen_start_info->nr_pages);
 746	mem_end = PFN_PHYS(max_pfn);
 747
 748	memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
 749	set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
 750
 
 
 
 
 751	op = xen_initial_domain() ?
 752		XENMEM_machine_memory_map :
 753		XENMEM_memory_map;
 754	rc = HYPERVISOR_memory_op(op, &memmap);
 755	if (rc == -ENOSYS) {
 756		BUG_ON(xen_initial_domain());
 757		memmap.nr_entries = 1;
 758		xen_e820_table.entries[0].addr = 0ULL;
 759		xen_e820_table.entries[0].size = mem_end;
 760		/* 8MB slack (to balance backend allocations). */
 761		xen_e820_table.entries[0].size += 8ULL << 20;
 762		xen_e820_table.entries[0].type = E820_TYPE_RAM;
 763		rc = 0;
 764	}
 765	BUG_ON(rc);
 766	BUG_ON(memmap.nr_entries == 0);
 767	xen_e820_table.nr_entries = memmap.nr_entries;
 768
 769	/*
 770	 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
 771	 * regions, so if we're using the machine memory map leave the
 772	 * region as RAM as it is in the pseudo-physical map.
 773	 *
 774	 * UNUSABLE regions in domUs are not handled and will need
 775	 * a patch in the future.
 776	 */
 777	if (xen_initial_domain())
 778		xen_ignore_unusable();
 779
 
 
 
 
 
 
 
 
 
 780	/* Make sure the Xen-supplied memory map is well-ordered. */
 781	e820__update_table(&xen_e820_table);
 782
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 783	max_pages = xen_get_max_pages();
 784
 785	/* How many extra pages do we need due to remapping? */
 786	max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
 787
 788	if (max_pages > max_pfn)
 789		extra_pages += max_pages - max_pfn;
 790
 791	/*
 792	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
 793	 * factor the base size.  On non-highmem systems, the base
 794	 * size is the full initial memory allocation; on highmem it
 795	 * is limited to the max size of lowmem, so that it doesn't
 796	 * get completely filled.
 797	 *
 798	 * Make sure we have no memory above max_pages, as this area
 799	 * isn't handled by the p2m management.
 800	 *
 801	 * In principle there could be a problem in lowmem systems if
 802	 * the initial memory is also very large with respect to
 803	 * lowmem, but we won't try to deal with that here.
 804	 */
 805	extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
 806			   extra_pages, max_pages - max_pfn);
 807	i = 0;
 808	addr = xen_e820_table.entries[0].addr;
 809	size = xen_e820_table.entries[0].size;
 810	while (i < xen_e820_table.nr_entries) {
 
 811
 812		chunk_size = size;
 813		type = xen_e820_table.entries[i].type;
 814
 
 
 
 815		if (type == E820_TYPE_RAM) {
 816			if (addr < mem_end) {
 817				chunk_size = min(size, mem_end - addr);
 818			} else if (extra_pages) {
 819				chunk_size = min(size, PFN_PHYS(extra_pages));
 820				pfn_s = PFN_UP(addr);
 821				n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
 822				extra_pages -= n_pfns;
 823				xen_add_extra_mem(pfn_s, n_pfns);
 824				xen_max_p2m_pfn = pfn_s + n_pfns;
 825			} else
 826				type = E820_TYPE_UNUSABLE;
 827		}
 828
 829		xen_align_and_add_e820_region(addr, chunk_size, type);
 
 830
 831		addr += chunk_size;
 832		size -= chunk_size;
 833		if (size == 0) {
 834			i++;
 835			if (i < xen_e820_table.nr_entries) {
 836				addr = xen_e820_table.entries[i].addr;
 837				size = xen_e820_table.entries[i].size;
 838			}
 839		}
 840	}
 841
 842	/*
 843	 * Set the rest as identity mapped, in case PCI BARs are
 844	 * located here.
 845	 */
 846	set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
 847
 848	/*
 849	 * In domU, the ISA region is normal, usable memory, but we
 850	 * reserve ISA memory anyway because too many things poke
 851	 * about in there.
 852	 */
 853	e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
 854
 855	e820__update_table(e820_table);
 856
 857	/*
 858	 * Check whether the kernel itself conflicts with the target E820 map.
 859	 * Failing now is better than running into weird problems later due
 860	 * to relocating (and even reusing) pages with kernel text or data.
 861	 */
 862	if (xen_is_e820_reserved(__pa_symbol(_text),
 863			__pa_symbol(__bss_stop) - __pa_symbol(_text))) {
 864		xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
 865		BUG();
 866	}
 867
 868	/*
 869	 * Check for a conflict of the hypervisor supplied page tables with
 870	 * the target E820 map.
 871	 */
 872	xen_pt_check_e820();
 873
 874	xen_reserve_xen_mfnlist();
 875
 876	/* Check for a conflict of the initrd with the target E820 map. */
 877	if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
 878				 boot_params.hdr.ramdisk_size)) {
 879		phys_addr_t new_area, start, size;
 880
 881		new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
 882		if (!new_area) {
 883			xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
 884			BUG();
 885		}
 886
 887		start = boot_params.hdr.ramdisk_image;
 888		size = boot_params.hdr.ramdisk_size;
 889		xen_phys_memcpy(new_area, start, size);
 890		pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
 891			start, start + size, new_area, new_area + size);
 892		memblock_free(start, size);
 893		boot_params.hdr.ramdisk_image = new_area;
 894		boot_params.ext_ramdisk_image = new_area >> 32;
 895	}
 896
 897	/*
 898	 * Set identity map on non-RAM pages and prepare remapping the
 899	 * underlying RAM.
 900	 */
 901	xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
 902
 903	pr_info("Released %ld page(s)\n", xen_released_pages);
 904
 905	return "Xen";
 906}
 907
 908/*
 909 * Machine specific memory setup for auto-translated guests.
 910 */
 911char * __init xen_auto_xlated_memory_setup(void)
 912{
 913	struct xen_memory_map memmap;
 914	int i;
 915	int rc;
 916
 917	memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
 918	set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
 919
 920	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
 921	if (rc < 0)
 922		panic("No memory map (%d)\n", rc);
 923
 924	xen_e820_table.nr_entries = memmap.nr_entries;
 925
 926	e820__update_table(&xen_e820_table);
 927
 928	for (i = 0; i < xen_e820_table.nr_entries; i++)
 929		e820__range_add(xen_e820_table.entries[i].addr, xen_e820_table.entries[i].size, xen_e820_table.entries[i].type);
 930
 931	/* Remove p2m info, it is not needed. */
 932	xen_start_info->mfn_list = 0;
 933	xen_start_info->first_p2m_pfn = 0;
 934	xen_start_info->nr_p2m_frames = 0;
 935
 936	return "Xen";
 937}
 938
 939/*
 940 * Set the bit indicating "nosegneg" library variants should be used.
 941 * We only need to bother in pure 32-bit mode; compat 32-bit processes
 942 * can have un-truncated segments, so wrapping around is allowed.
 943 */
 944static void __init fiddle_vdso(void)
 945{
 946#ifdef CONFIG_X86_32
 947	u32 *mask = vdso_image_32.data +
 948		vdso_image_32.sym_VDSO32_NOTE_MASK;
 949	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
 950#endif
 951}
 952
 953static int register_callback(unsigned type, const void *func)
 954{
 955	struct callback_register callback = {
 956		.type = type,
 957		.address = XEN_CALLBACK(__KERNEL_CS, func),
 958		.flags = CALLBACKF_mask_events,
 959	};
 960
 961	return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
 962}
 963
 964void xen_enable_sysenter(void)
 965{
 966	int ret;
 967	unsigned sysenter_feature;
 968
 969#ifdef CONFIG_X86_32
 970	sysenter_feature = X86_FEATURE_SEP;
 971#else
 972	sysenter_feature = X86_FEATURE_SYSENTER32;
 973#endif
 974
 975	if (!boot_cpu_has(sysenter_feature))
 976		return;
 977
 978	ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
 979	if(ret != 0)
 980		setup_clear_cpu_cap(sysenter_feature);
 981}
 982
 983void xen_enable_syscall(void)
 984{
 985#ifdef CONFIG_X86_64
 986	int ret;
 987
 988	ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
 989	if (ret != 0) {
 990		printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
 991		/* Pretty fatal; 64-bit userspace has no other
 992		   mechanism for syscalls. */
 993	}
 994
 995	if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
 996		ret = register_callback(CALLBACKTYPE_syscall32,
 997					xen_syscall32_target);
 998		if (ret != 0)
 999			setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
1000	}
1001#endif /* CONFIG_X86_64 */
1002}
1003
1004void __init xen_pvmmu_arch_setup(void)
1005{
1006	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
1007	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1008
1009	HYPERVISOR_vm_assist(VMASST_CMD_enable,
1010			     VMASST_TYPE_pae_extended_cr3);
1011
1012	if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
1013	    register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1014		BUG();
1015
1016	xen_enable_sysenter();
1017	xen_enable_syscall();
1018}
1019
1020/* This function is not called for HVM domains */
1021void __init xen_arch_setup(void)
1022{
1023	xen_panic_handler_init();
1024	xen_pvmmu_arch_setup();
1025
1026#ifdef CONFIG_ACPI
1027	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1028		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1029		disable_acpi();
1030	}
1031#endif
1032
1033	memcpy(boot_command_line, xen_start_info->cmd_line,
1034	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1035	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1036
1037	/* Set up idle, making sure it calls safe_halt() pvop */
1038	disable_cpuidle();
1039	disable_cpufreq();
1040	WARN_ON(xen_set_default_idle());
1041	fiddle_vdso();
1042#ifdef CONFIG_NUMA
1043	numa_off = 1;
1044#endif
1045}