Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1350 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
new file mode 100644
index 0000000000..fb8cf95338
--- /dev/null
+++ b/arch/x86/kernel/e820.c
@@ -0,0 +1,1350 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Low level x86 E820 memory map handling functions.
+ *
+ * The firmware and bootloader passes us the "E820 table", which is the primary
+ * physical memory layout description available about x86 systems.
+ *
+ * The kernel takes the E820 memory layout and optionally modifies it with
+ * quirks and other tweaks, and feeds that into the generic Linux memory
+ * allocation code routines via a platform independent interface (memblock, etc.).
+ */
+#include <linux/crash_dump.h>
+#include <linux/memblock.h>
+#include <linux/suspend.h>
+#include <linux/acpi.h>
+#include <linux/firmware-map.h>
+#include <linux/sort.h>
+#include <linux/memory_hotplug.h>
+
+#include <asm/e820/api.h>
+#include <asm/setup.h>
+
+/*
+ * We organize the E820 table into three main data structures:
+ *
+ * - 'e820_table_firmware': the original firmware version passed to us by the
+ *   bootloader - not modified by the kernel. It is composed of two parts:
+ *   the first 128 E820 memory entries in boot_params.e820_table and the remaining
+ *   (if any) entries of the SETUP_E820_EXT nodes. We use this to:
+ *
+ *       - inform the user about the firmware's notion of memory layout
+ *         via /sys/firmware/memmap
+ *
+ *       - the hibernation code uses it to generate a kernel-independent CRC32
+ *         checksum of the physical memory layout of a system.
+ *
+ * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
+ *   passed to us by the bootloader - the major difference between
+ *   e820_table_firmware[] and this one is that, the latter marks the setup_data
+ *   list created by the EFI boot stub as reserved, so that kexec can reuse the
+ *   setup_data information in the second kernel. Besides, e820_table_kexec[]
+ *   might also be modified by the kexec itself to fake a mptable.
+ *   We use this to:
+ *
+ *       - kexec, which is a bootloader in disguise, uses the original E820
+ *         layout to pass to the kexec-ed kernel. This way the original kernel
+ *         can have a restricted E820 map while the kexec()-ed kexec-kernel
+ *         can have access to full memory - etc.
+ *
+ * - 'e820_table': this is the main E820 table that is massaged by the
+ *   low level x86 platform code, or modified by boot parameters, before
+ *   passed on to higher level MM layers.
+ *
+ * Once the E820 map has been converted to the standard Linux memory layout
+ * information its role stops - modifying it has no effect and does not get
+ * re-propagated. So its main role is a temporary bootstrap storage of firmware
+ * specific memory layout data during early bootup.
+ */
+static struct e820_table e820_table_init		__initdata;
+static struct e820_table e820_table_kexec_init		__initdata;
+static struct e820_table e820_table_firmware_init	__initdata;
+
+struct e820_table *e820_table __refdata			= &e820_table_init;
+struct e820_table *e820_table_kexec __refdata		= &e820_table_kexec_init;
+struct e820_table *e820_table_firmware __refdata	= &e820_table_firmware_init;
+
+/* For PCI or other memory-mapped resources */
+unsigned long pci_mem_start = 0xaeedbabe;
+#ifdef CONFIG_PCI
+EXPORT_SYMBOL(pci_mem_start);
+#endif
+
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+static bool _e820__mapped_any(struct e820_table *table,
+			      u64 start, u64 end, enum e820_type type)
+{
+	int i;
+
+	for (i = 0; i < table->nr_entries; i++) {
+		struct e820_entry *entry = &table->entries[i];
+
+		if (type && entry->type != type)
+			continue;
+		if (entry->addr >= end || entry->addr + entry->size <= start)
+			continue;
+		return true;
+	}
+	return false;
+}
+
+bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type)
+{
+	return _e820__mapped_any(e820_table_firmware, start, end, type);
+}
+EXPORT_SYMBOL_GPL(e820__mapped_raw_any);
+
+bool e820__mapped_any(u64 start, u64 end, enum e820_type type)
+{
+	return _e820__mapped_any(e820_table, start, end, type);
+}
+EXPORT_SYMBOL_GPL(e820__mapped_any);
+
+/*
+ * This function checks if the entire <start,end> range is mapped with 'type'.
+ *
+ * Note: this function only works correctly once the E820 table is sorted and
+ * not-overlapping (at least for the range specified), which is the case normally.
+ */
+static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
+					     enum e820_type type)
+{
+	int i;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+
+		if (type && entry->type != type)
+			continue;
+
+		/* Is the region (part) in overlap with the current region? */
+		if (entry->addr >= end || entry->addr + entry->size <= start)
+			continue;
+
+		/*
+		 * If the region is at the beginning of <start,end> we move
+		 * 'start' to the end of the region since it's ok until there
+		 */
+		if (entry->addr <= start)
+			start = entry->addr + entry->size;
+
+		/*
+		 * If 'start' is now at or beyond 'end', we're done, full
+		 * coverage of the desired range exists:
+		 */
+		if (start >= end)
+			return entry;
+	}
+
+	return NULL;
+}
+
+/*
+ * This function checks if the entire range <start,end> is mapped with type.
+ */
+bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
+{
+	return __e820__mapped_all(start, end, type);
+}
+
+/*
+ * This function returns the type associated with the range <start,end>.
+ */
+int e820__get_entry_type(u64 start, u64 end)
+{
+	struct e820_entry *entry = __e820__mapped_all(start, end, 0);
+
+	return entry ? entry->type : -EINVAL;
+}
+
+/*
+ * Add a memory region to the kernel E820 map.
+ */
+static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
+{
+	int x = table->nr_entries;
+
+	if (x >= ARRAY_SIZE(table->entries)) {
+		pr_err("too many entries; ignoring [mem %#010llx-%#010llx]\n",
+		       start, start + size - 1);
+		return;
+	}
+
+	table->entries[x].addr = start;
+	table->entries[x].size = size;
+	table->entries[x].type = type;
+	table->nr_entries++;
+}
+
+void __init e820__range_add(u64 start, u64 size, enum e820_type type)
+{
+	__e820__range_add(e820_table, start, size, type);
+}
+
+static void __init e820_print_type(enum e820_type type)
+{
+	switch (type) {
+	case E820_TYPE_RAM:		/* Fall through: */
+	case E820_TYPE_RESERVED_KERN:	pr_cont("usable");			break;
+	case E820_TYPE_RESERVED:	pr_cont("reserved");			break;
+	case E820_TYPE_SOFT_RESERVED:	pr_cont("soft reserved");		break;
+	case E820_TYPE_ACPI:		pr_cont("ACPI data");			break;
+	case E820_TYPE_NVS:		pr_cont("ACPI NVS");			break;
+	case E820_TYPE_UNUSABLE:	pr_cont("unusable");			break;
+	case E820_TYPE_PMEM:		/* Fall through: */
+	case E820_TYPE_PRAM:		pr_cont("persistent (type %u)", type);	break;
+	default:			pr_cont("type %u", type);		break;
+	}
+}
+
+void __init e820__print_table(char *who)
+{
+	int i;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		pr_info("%s: [mem %#018Lx-%#018Lx] ",
+			who,
+			e820_table->entries[i].addr,
+			e820_table->entries[i].addr + e820_table->entries[i].size - 1);
+
+		e820_print_type(e820_table->entries[i].type);
+		pr_cont("\n");
+	}
+}
+
+/*
+ * Sanitize an E820 map.
+ *
+ * Some E820 layouts include overlapping entries. The following
+ * replaces the original E820 map with a new one, removing overlaps,
+ * and resolving conflicting memory types in favor of highest
+ * numbered type.
+ *
+ * The input parameter 'entries' points to an array of 'struct
+ * e820_entry' which on entry has elements in the range [0, *nr_entries)
+ * valid, and which has space for up to max_nr_entries entries.
+ * On return, the resulting sanitized E820 map entries will be in
+ * overwritten in the same location, starting at 'entries'.
+ *
+ * The integer pointed to by nr_entries must be valid on entry (the
+ * current number of valid entries located at 'entries'). If the
+ * sanitizing succeeds the *nr_entries will be updated with the new
+ * number of valid entries (something no more than max_nr_entries).
+ *
+ * The return value from e820__update_table() is zero if it
+ * successfully 'sanitized' the map entries passed in, and is -1
+ * if it did nothing, which can happen if either of (1) it was
+ * only passed one map entry, or (2) any of the input map entries
+ * were invalid (start + size < start, meaning that the size was
+ * so big the described memory range wrapped around through zero.)
+ *
+ *	Visually we're performing the following
+ *	(1,2,3,4 = memory types)...
+ *
+ *	Sample memory map (w/overlaps):
+ *	   ____22__________________
+ *	   ______________________4_
+ *	   ____1111________________
+ *	   _44_____________________
+ *	   11111111________________
+ *	   ____________________33__
+ *	   ___________44___________
+ *	   __________33333_________
+ *	   ______________22________
+ *	   ___________________2222_
+ *	   _________111111111______
+ *	   _____________________11_
+ *	   _________________4______
+ *
+ *	Sanitized equivalent (no overlap):
+ *	   1_______________________
+ *	   _44_____________________
+ *	   ___1____________________
+ *	   ____22__________________
+ *	   ______11________________
+ *	   _________1______________
+ *	   __________3_____________
+ *	   ___________44___________
+ *	   _____________33_________
+ *	   _______________2________
+ *	   ________________1_______
+ *	   _________________4______
+ *	   ___________________2____
+ *	   ____________________33__
+ *	   ______________________4_
+ */
+struct change_member {
+	/* Pointer to the original entry: */
+	struct e820_entry	*entry;
+	/* Address for this change point: */
+	unsigned long long	addr;
+};
+
+static struct change_member	change_point_list[2*E820_MAX_ENTRIES]	__initdata;
+static struct change_member	*change_point[2*E820_MAX_ENTRIES]	__initdata;
+static struct e820_entry	*overlap_list[E820_MAX_ENTRIES]		__initdata;
+static struct e820_entry	new_entries[E820_MAX_ENTRIES]		__initdata;
+
+static int __init cpcompare(const void *a, const void *b)
+{
+	struct change_member * const *app = a, * const *bpp = b;
+	const struct change_member *ap = *app, *bp = *bpp;
+
+	/*
+	 * Inputs are pointers to two elements of change_point[].  If their
+	 * addresses are not equal, their difference dominates.  If the addresses
+	 * are equal, then consider one that represents the end of its region
+	 * to be greater than one that does not.
+	 */
+	if (ap->addr != bp->addr)
+		return ap->addr > bp->addr ? 1 : -1;
+
+	return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
+}
+
+static bool e820_nomerge(enum e820_type type)
+{
+	/*
+	 * These types may indicate distinct platform ranges aligned to
+	 * numa node, protection domain, performance domain, or other
+	 * boundaries. Do not merge them.
+	 */
+	if (type == E820_TYPE_PRAM)
+		return true;
+	if (type == E820_TYPE_SOFT_RESERVED)
+		return true;
+	return false;
+}
+
+int __init e820__update_table(struct e820_table *table)
+{
+	struct e820_entry *entries = table->entries;
+	u32 max_nr_entries = ARRAY_SIZE(table->entries);
+	enum e820_type current_type, last_type;
+	unsigned long long last_addr;
+	u32 new_nr_entries, overlap_entries;
+	u32 i, chg_idx, chg_nr;
+
+	/* If there's only one memory region, don't bother: */
+	if (table->nr_entries < 2)
+		return -1;
+
+	BUG_ON(table->nr_entries > max_nr_entries);
+
+	/* Bail out if we find any unreasonable addresses in the map: */
+	for (i = 0; i < table->nr_entries; i++) {
+		if (entries[i].addr + entries[i].size < entries[i].addr)
+			return -1;
+	}
+
+	/* Create pointers for initial change-point information (for sorting): */
+	for (i = 0; i < 2 * table->nr_entries; i++)
+		change_point[i] = &change_point_list[i];
+
+	/*
+	 * Record all known change-points (starting and ending addresses),
+	 * omitting empty memory regions:
+	 */
+	chg_idx = 0;
+	for (i = 0; i < table->nr_entries; i++)	{
+		if (entries[i].size != 0) {
+			change_point[chg_idx]->addr	= entries[i].addr;
+			change_point[chg_idx++]->entry	= &entries[i];
+			change_point[chg_idx]->addr	= entries[i].addr + entries[i].size;
+			change_point[chg_idx++]->entry	= &entries[i];
+		}
+	}
+	chg_nr = chg_idx;
+
+	/* Sort change-point list by memory addresses (low -> high): */
+	sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
+
+	/* Create a new memory map, removing overlaps: */
+	overlap_entries = 0;	 /* Number of entries in the overlap table */
+	new_nr_entries = 0;	 /* Index for creating new map entries */
+	last_type = 0;		 /* Start with undefined memory type */
+	last_addr = 0;		 /* Start with 0 as last starting address */
+
+	/* Loop through change-points, determining effect on the new map: */
+	for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
+		/* Keep track of all overlapping entries */
+		if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
+			/* Add map entry to overlap list (> 1 entry implies an overlap) */
+			overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
+		} else {
+			/* Remove entry from list (order independent, so swap with last): */
+			for (i = 0; i < overlap_entries; i++) {
+				if (overlap_list[i] == change_point[chg_idx]->entry)
+					overlap_list[i] = overlap_list[overlap_entries-1];
+			}
+			overlap_entries--;
+		}
+		/*
+		 * If there are overlapping entries, decide which
+		 * "type" to use (larger value takes precedence --
+		 * 1=usable, 2,3,4,4+=unusable)
+		 */
+		current_type = 0;
+		for (i = 0; i < overlap_entries; i++) {
+			if (overlap_list[i]->type > current_type)
+				current_type = overlap_list[i]->type;
+		}
+
+		/* Continue building up new map based on this information: */
+		if (current_type != last_type || e820_nomerge(current_type)) {
+			if (last_type) {
+				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
+				/* Move forward only if the new size was non-zero: */
+				if (new_entries[new_nr_entries].size != 0)
+					/* No more space left for new entries? */
+					if (++new_nr_entries >= max_nr_entries)
+						break;
+			}
+			if (current_type) {
+				new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
+				new_entries[new_nr_entries].type = current_type;
+				last_addr = change_point[chg_idx]->addr;
+			}
+			last_type = current_type;
+		}
+	}
+
+	/* Copy the new entries into the original location: */
+	memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
+	table->nr_entries = new_nr_entries;
+
+	return 0;
+}
+
+static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
+{
+	struct boot_e820_entry *entry = entries;
+
+	while (nr_entries) {
+		u64 start = entry->addr;
+		u64 size = entry->size;
+		u64 end = start + size - 1;
+		u32 type = entry->type;
+
+		/* Ignore the entry on 64-bit overflow: */
+		if (start > end && likely(size))
+			return -1;
+
+		e820__range_add(start, size, type);
+
+		entry++;
+		nr_entries--;
+	}
+	return 0;
+}
+
+/*
+ * Copy the BIOS E820 map into a safe place.
+ *
+ * Sanity-check it while we're at it..
+ *
+ * If we're lucky and live on a modern system, the setup code
+ * will have given us a memory map that we can use to properly
+ * set up memory.  If we aren't, we'll fake a memory map.
+ */
+static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
+{
+	/* Only one memory region (or negative)? Ignore it */
+	if (nr_entries < 2)
+		return -1;
+
+	return __append_e820_table(entries, nr_entries);
+}
+
+static u64 __init
+__e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
+{
+	u64 end;
+	unsigned int i;
+	u64 real_updated_size = 0;
+
+	BUG_ON(old_type == new_type);
+
+	if (size > (ULLONG_MAX - start))
+		size = ULLONG_MAX - start;
+
+	end = start + size;
+	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
+	e820_print_type(old_type);
+	pr_cont(" ==> ");
+	e820_print_type(new_type);
+	pr_cont("\n");
+
+	for (i = 0; i < table->nr_entries; i++) {
+		struct e820_entry *entry = &table->entries[i];
+		u64 final_start, final_end;
+		u64 entry_end;
+
+		if (entry->type != old_type)
+			continue;
+
+		entry_end = entry->addr + entry->size;
+
+		/* Completely covered by new range? */
+		if (entry->addr >= start && entry_end <= end) {
+			entry->type = new_type;
+			real_updated_size += entry->size;
+			continue;
+		}
+
+		/* New range is completely covered? */
+		if (entry->addr < start && entry_end > end) {
+			__e820__range_add(table, start, size, new_type);
+			__e820__range_add(table, end, entry_end - end, entry->type);
+			entry->size = start - entry->addr;
+			real_updated_size += size;
+			continue;
+		}
+
+		/* Partially covered: */
+		final_start = max(start, entry->addr);
+		final_end = min(end, entry_end);
+		if (final_start >= final_end)
+			continue;
+
+		__e820__range_add(table, final_start, final_end - final_start, new_type);
+
+		real_updated_size += final_end - final_start;
+
+		/*
+		 * Left range could be head or tail, so need to update
+		 * its size first:
+		 */
+		entry->size -= final_end - final_start;
+		if (entry->addr < final_start)
+			continue;
+
+		entry->addr = final_end;
+	}
+	return real_updated_size;
+}
+
+u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
+{
+	return __e820__range_update(e820_table, start, size, old_type, new_type);
+}
+
+static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type old_type, enum e820_type  new_type)
+{
+	return __e820__range_update(e820_table_kexec, start, size, old_type, new_type);
+}
+
+/* Remove a range of memory from the E820 table: */
+u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
+{
+	int i;
+	u64 end;
+	u64 real_removed_size = 0;
+
+	if (size > (ULLONG_MAX - start))
+		size = ULLONG_MAX - start;
+
+	end = start + size;
+	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
+	if (check_type)
+		e820_print_type(old_type);
+	pr_cont("\n");
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+		u64 final_start, final_end;
+		u64 entry_end;
+
+		if (check_type && entry->type != old_type)
+			continue;
+
+		entry_end = entry->addr + entry->size;
+
+		/* Completely covered? */
+		if (entry->addr >= start && entry_end <= end) {
+			real_removed_size += entry->size;
+			memset(entry, 0, sizeof(*entry));
+			continue;
+		}
+
+		/* Is the new range completely covered? */
+		if (entry->addr < start && entry_end > end) {
+			e820__range_add(end, entry_end - end, entry->type);
+			entry->size = start - entry->addr;
+			real_removed_size += size;
+			continue;
+		}
+
+		/* Partially covered: */
+		final_start = max(start, entry->addr);
+		final_end = min(end, entry_end);
+		if (final_start >= final_end)
+			continue;
+
+		real_removed_size += final_end - final_start;
+
+		/*
+		 * Left range could be head or tail, so need to update
+		 * the size first:
+		 */
+		entry->size -= final_end - final_start;
+		if (entry->addr < final_start)
+			continue;
+
+		entry->addr = final_end;
+	}
+	return real_removed_size;
+}
+
+void __init e820__update_table_print(void)
+{
+	if (e820__update_table(e820_table))
+		return;
+
+	pr_info("modified physical RAM map:\n");
+	e820__print_table("modified");
+}
+
+static void __init e820__update_table_kexec(void)
+{
+	e820__update_table(e820_table_kexec);
+}
+
+#define MAX_GAP_END 0x100000000ull
+
+/*
+ * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).
+ */
+static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)
+{
+	unsigned long long last = MAX_GAP_END;
+	int i = e820_table->nr_entries;
+	int found = 0;
+
+	while (--i >= 0) {
+		unsigned long long start = e820_table->entries[i].addr;
+		unsigned long long end = start + e820_table->entries[i].size;
+
+		/*
+		 * Since "last" is at most 4GB, we know we'll
+		 * fit in 32 bits if this condition is true:
+		 */
+		if (last > end) {
+			unsigned long gap = last - end;
+
+			if (gap >= *gapsize) {
+				*gapsize = gap;
+				*gapstart = end;
+				found = 1;
+			}
+		}
+		if (start < last)
+			last = start;
+	}
+	return found;
+}
+
+/*
+ * Search for the biggest gap in the low 32 bits of the E820
+ * memory space. We pass this space to the PCI subsystem, so
+ * that it can assign MMIO resources for hotplug or
+ * unconfigured devices in.
+ *
+ * Hopefully the BIOS let enough space left.
+ */
+__init void e820__setup_pci_gap(void)
+{
+	unsigned long gapstart, gapsize;
+	int found;
+
+	gapsize = 0x400000;
+	found  = e820_search_gap(&gapstart, &gapsize);
+
+	if (!found) {
+#ifdef CONFIG_X86_64
+		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
+		pr_err("Cannot find an available gap in the 32-bit address range\n");
+		pr_err("PCI devices with unassigned 32-bit BARs may not work!\n");
+#else
+		gapstart = 0x10000000;
+#endif
+	}
+
+	/*
+	 * e820__reserve_resources_late() protects stolen RAM already:
+	 */
+	pci_mem_start = gapstart;
+
+	pr_info("[mem %#010lx-%#010lx] available for PCI devices\n",
+		gapstart, gapstart + gapsize - 1);
+}
+
+/*
+ * Called late during init, in free_initmem().
+ *
+ * Initial e820_table and e820_table_kexec are largish __initdata arrays.
+ *
+ * Copy them to a (usually much smaller) dynamically allocated area that is
+ * sized precisely after the number of e820 entries.
+ *
+ * This is done after we've performed all the fixes and tweaks to the tables.
+ * All functions which modify them are __init functions, which won't exist
+ * after free_initmem().
+ */
+__init void e820__reallocate_tables(void)
+{
+	struct e820_table *n;
+	int size;
+
+	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
+	n = kmemdup(e820_table, size, GFP_KERNEL);
+	BUG_ON(!n);
+	e820_table = n;
+
+	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
+	n = kmemdup(e820_table_kexec, size, GFP_KERNEL);
+	BUG_ON(!n);
+	e820_table_kexec = n;
+
+	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
+	n = kmemdup(e820_table_firmware, size, GFP_KERNEL);
+	BUG_ON(!n);
+	e820_table_firmware = n;
+}
+
+/*
+ * Because of the small fixed size of struct boot_params, only the first
+ * 128 E820 memory entries are passed to the kernel via boot_params.e820_table,
+ * the remaining (if any) entries are passed via the SETUP_E820_EXT node of
+ * struct setup_data, which is parsed here.
+ */
+void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
+{
+	int entries;
+	struct boot_e820_entry *extmap;
+	struct setup_data *sdata;
+
+	sdata = early_memremap(phys_addr, data_len);
+	entries = sdata->len / sizeof(*extmap);
+	extmap = (struct boot_e820_entry *)(sdata->data);
+
+	__append_e820_table(extmap, entries);
+	e820__update_table(e820_table);
+
+	memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
+	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+
+	early_memunmap(sdata, data_len);
+	pr_info("extended physical RAM map:\n");
+	e820__print_table("extended");
+}
+
+/*
+ * Find the ranges of physical addresses that do not correspond to
+ * E820 RAM areas and register the corresponding pages as 'nosave' for
+ * hibernation (32-bit) or software suspend and suspend to RAM (64-bit).
+ *
+ * This function requires the E820 map to be sorted and without any
+ * overlapping entries.
+ */
+void __init e820__register_nosave_regions(unsigned long limit_pfn)
+{
+	int i;
+	unsigned long pfn = 0;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+
+		if (pfn < PFN_UP(entry->addr))
+			register_nosave_region(pfn, PFN_UP(entry->addr));
+
+		pfn = PFN_DOWN(entry->addr + entry->size);
+
+		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
+			register_nosave_region(PFN_UP(entry->addr), pfn);
+
+		if (pfn >= limit_pfn)
+			break;
+	}
+}
+
+#ifdef CONFIG_ACPI
+/*
+ * Register ACPI NVS memory regions, so that we can save/restore them during
+ * hibernation and the subsequent resume:
+ */
+static int __init e820__register_nvs_regions(void)
+{
+	int i;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+
+		if (entry->type == E820_TYPE_NVS)
+			acpi_nvs_register(entry->addr, entry->size);
+	}
+
+	return 0;
+}
+core_initcall(e820__register_nvs_regions);
+#endif
+
+/*
+ * Allocate the requested number of bytes with the requested alignment
+ * and return (the physical address) to the caller. Also register this
+ * range in the 'kexec' E820 table as a reserved range.
+ *
+ * This allows kexec to fake a new mptable, as if it came from the real
+ * system.
+ */
+u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
+{
+	u64 addr;
+
+	addr = memblock_phys_alloc(size, align);
+	if (addr) {
+		e820__range_update_kexec(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
+		pr_info("update e820_table_kexec for e820__memblock_alloc_reserved()\n");
+		e820__update_table_kexec();
+	}
+
+	return addr;
+}
+
+#ifdef CONFIG_X86_32
+# ifdef CONFIG_X86_PAE
+#  define MAX_ARCH_PFN		(1ULL<<(36-PAGE_SHIFT))
+# else
+#  define MAX_ARCH_PFN		(1ULL<<(32-PAGE_SHIFT))
+# endif
+#else /* CONFIG_X86_32 */
+# define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
+#endif
+
+/*
+ * Find the highest page frame number we have available
+ */
+static unsigned long __init e820_end_pfn(unsigned long limit_pfn, enum e820_type type)
+{
+	int i;
+	unsigned long last_pfn = 0;
+	unsigned long max_arch_pfn = MAX_ARCH_PFN;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+		unsigned long start_pfn;
+		unsigned long end_pfn;
+
+		if (entry->type != type)
+			continue;
+
+		start_pfn = entry->addr >> PAGE_SHIFT;
+		end_pfn = (entry->addr + entry->size) >> PAGE_SHIFT;
+
+		if (start_pfn >= limit_pfn)
+			continue;
+		if (end_pfn > limit_pfn) {
+			last_pfn = limit_pfn;
+			break;
+		}
+		if (end_pfn > last_pfn)
+			last_pfn = end_pfn;
+	}
+
+	if (last_pfn > max_arch_pfn)
+		last_pfn = max_arch_pfn;
+
+	pr_info("last_pfn = %#lx max_arch_pfn = %#lx\n",
+		last_pfn, max_arch_pfn);
+	return last_pfn;
+}
+
+unsigned long __init e820__end_of_ram_pfn(void)
+{
+	return e820_end_pfn(MAX_ARCH_PFN, E820_TYPE_RAM);
+}
+
+unsigned long __init e820__end_of_low_ram_pfn(void)
+{
+	return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_TYPE_RAM);
+}
+
+static void __init early_panic(char *msg)
+{
+	early_printk(msg);
+	panic(msg);
+}
+
+static int userdef __initdata;
+
+/* The "mem=nopentium" boot option disables 4MB page tables on 32-bit kernels: */
+static int __init parse_memopt(char *p)
+{
+	u64 mem_size;
+
+	if (!p)
+		return -EINVAL;
+
+	if (!strcmp(p, "nopentium")) {
+#ifdef CONFIG_X86_32
+		setup_clear_cpu_cap(X86_FEATURE_PSE);
+		return 0;
+#else
+		pr_warn("mem=nopentium ignored! (only supported on x86_32)\n");
+		return -EINVAL;
+#endif
+	}
+
+	userdef = 1;
+	mem_size = memparse(p, &p);
+
+	/* Don't remove all memory when getting "mem={invalid}" parameter: */
+	if (mem_size == 0)
+		return -EINVAL;
+
+	e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+	max_mem_size = mem_size;
+#endif
+
+	return 0;
+}
+early_param("mem", parse_memopt);
+
+static int __init parse_memmap_one(char *p)
+{
+	char *oldp;
+	u64 start_at, mem_size;
+
+	if (!p)
+		return -EINVAL;
+
+	if (!strncmp(p, "exactmap", 8)) {
+		e820_table->nr_entries = 0;
+		userdef = 1;
+		return 0;
+	}
+
+	oldp = p;
+	mem_size = memparse(p, &p);
+	if (p == oldp)
+		return -EINVAL;
+
+	userdef = 1;
+	if (*p == '@') {
+		start_at = memparse(p+1, &p);
+		e820__range_add(start_at, mem_size, E820_TYPE_RAM);
+	} else if (*p == '#') {
+		start_at = memparse(p+1, &p);
+		e820__range_add(start_at, mem_size, E820_TYPE_ACPI);
+	} else if (*p == '$') {
+		start_at = memparse(p+1, &p);
+		e820__range_add(start_at, mem_size, E820_TYPE_RESERVED);
+	} else if (*p == '!') {
+		start_at = memparse(p+1, &p);
+		e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
+	} else if (*p == '%') {
+		enum e820_type from = 0, to = 0;
+
+		start_at = memparse(p + 1, &p);
+		if (*p == '-')
+			from = simple_strtoull(p + 1, &p, 0);
+		if (*p == '+')
+			to = simple_strtoull(p + 1, &p, 0);
+		if (*p != '\0')
+			return -EINVAL;
+		if (from && to)
+			e820__range_update(start_at, mem_size, from, to);
+		else if (to)
+			e820__range_add(start_at, mem_size, to);
+		else if (from)
+			e820__range_remove(start_at, mem_size, from, 1);
+		else
+			e820__range_remove(start_at, mem_size, 0, 0);
+	} else {
+		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
+	}
+
+	return *p == '\0' ? 0 : -EINVAL;
+}
+
+static int __init parse_memmap_opt(char *str)
+{
+	while (str) {
+		char *k = strchr(str, ',');
+
+		if (k)
+			*k++ = 0;
+
+		parse_memmap_one(str);
+		str = k;
+	}
+
+	return 0;
+}
+early_param("memmap", parse_memmap_opt);
+
+/*
+ * Reserve all entries from the bootloader's extensible data nodes list,
+ * because if present we are going to use it later on to fetch e820
+ * entries from it:
+ */
+void __init e820__reserve_setup_data(void)
+{
+	struct setup_indirect *indirect;
+	struct setup_data *data;
+	u64 pa_data, pa_next;
+	u32 len;
+
+	pa_data = boot_params.hdr.setup_data;
+	if (!pa_data)
+		return;
+
+	while (pa_data) {
+		data = early_memremap(pa_data, sizeof(*data));
+		if (!data) {
+			pr_warn("e820: failed to memremap setup_data entry\n");
+			return;
+		}
+
+		len = sizeof(*data);
+		pa_next = data->next;
+
+		e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+
+		/*
+		 * SETUP_EFI and SETUP_IMA are supplied by kexec and do not need
+		 * to be reserved.
+		 */
+		if (data->type != SETUP_EFI && data->type != SETUP_IMA)
+			e820__range_update_kexec(pa_data,
+						 sizeof(*data) + data->len,
+						 E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+
+		if (data->type == SETUP_INDIRECT) {
+			len += data->len;
+			early_memunmap(data, sizeof(*data));
+			data = early_memremap(pa_data, len);
+			if (!data) {
+				pr_warn("e820: failed to memremap indirect setup_data\n");
+				return;
+			}
+
+			indirect = (struct setup_indirect *)data->data;
+
+			if (indirect->type != SETUP_INDIRECT) {
+				e820__range_update(indirect->addr, indirect->len,
+						   E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+				e820__range_update_kexec(indirect->addr, indirect->len,
+							 E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+			}
+		}
+
+		pa_data = pa_next;
+		early_memunmap(data, len);
+	}
+
+	e820__update_table(e820_table);
+	e820__update_table(e820_table_kexec);
+
+	pr_info("extended physical RAM map:\n");
+	e820__print_table("reserve setup_data");
+}
+
+/*
+ * Called after parse_early_param(), after early parameters (such as mem=)
+ * have been processed, in which case we already have an E820 table filled in
+ * via the parameter callback function(s), but it's not sorted and printed yet:
+ */
+void __init e820__finish_early_params(void)
+{
+	if (userdef) {
+		if (e820__update_table(e820_table) < 0)
+			early_panic("Invalid user supplied memory map");
+
+		pr_info("user-defined physical RAM map:\n");
+		e820__print_table("user");
+	}
+}
+
+static const char *__init e820_type_to_string(struct e820_entry *entry)
+{
+	switch (entry->type) {
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		return "System RAM";
+	case E820_TYPE_ACPI:		return "ACPI Tables";
+	case E820_TYPE_NVS:		return "ACPI Non-volatile Storage";
+	case E820_TYPE_UNUSABLE:	return "Unusable memory";
+	case E820_TYPE_PRAM:		return "Persistent Memory (legacy)";
+	case E820_TYPE_PMEM:		return "Persistent Memory";
+	case E820_TYPE_RESERVED:	return "Reserved";
+	case E820_TYPE_SOFT_RESERVED:	return "Soft Reserved";
+	default:			return "Unknown E820 type";
+	}
+}
+
+static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
+{
+	switch (entry->type) {
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		return IORESOURCE_SYSTEM_RAM;
+	case E820_TYPE_ACPI:		/* Fall-through: */
+	case E820_TYPE_NVS:		/* Fall-through: */
+	case E820_TYPE_UNUSABLE:	/* Fall-through: */
+	case E820_TYPE_PRAM:		/* Fall-through: */
+	case E820_TYPE_PMEM:		/* Fall-through: */
+	case E820_TYPE_RESERVED:	/* Fall-through: */
+	case E820_TYPE_SOFT_RESERVED:	/* Fall-through: */
+	default:			return IORESOURCE_MEM;
+	}
+}
+
+static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
+{
+	switch (entry->type) {
+	case E820_TYPE_ACPI:		return IORES_DESC_ACPI_TABLES;
+	case E820_TYPE_NVS:		return IORES_DESC_ACPI_NV_STORAGE;
+	case E820_TYPE_PMEM:		return IORES_DESC_PERSISTENT_MEMORY;
+	case E820_TYPE_PRAM:		return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
+	case E820_TYPE_RESERVED:	return IORES_DESC_RESERVED;
+	case E820_TYPE_SOFT_RESERVED:	return IORES_DESC_SOFT_RESERVED;
+	case E820_TYPE_RESERVED_KERN:	/* Fall-through: */
+	case E820_TYPE_RAM:		/* Fall-through: */
+	case E820_TYPE_UNUSABLE:	/* Fall-through: */
+	default:			return IORES_DESC_NONE;
+	}
+}
+
+static bool __init do_mark_busy(enum e820_type type, struct resource *res)
+{
+	/* this is the legacy bios/dos rom-shadow + mmio region */
+	if (res->start < (1ULL<<20))
+		return true;
+
+	/*
+	 * Treat persistent memory and other special memory ranges like
+	 * device memory, i.e. reserve it for exclusive use of a driver
+	 */
+	switch (type) {
+	case E820_TYPE_RESERVED:
+	case E820_TYPE_SOFT_RESERVED:
+	case E820_TYPE_PRAM:
+	case E820_TYPE_PMEM:
+		return false;
+	case E820_TYPE_RESERVED_KERN:
+	case E820_TYPE_RAM:
+	case E820_TYPE_ACPI:
+	case E820_TYPE_NVS:
+	case E820_TYPE_UNUSABLE:
+	default:
+		return true;
+	}
+}
+
+/*
+ * Mark E820 reserved areas as busy for the resource manager:
+ */
+
+static struct resource __initdata *e820_res;
+
+void __init e820__reserve_resources(void)
+{
+	int i;
+	struct resource *res;
+	u64 end;
+
+	res = memblock_alloc(sizeof(*res) * e820_table->nr_entries,
+			     SMP_CACHE_BYTES);
+	if (!res)
+		panic("%s: Failed to allocate %zu bytes\n", __func__,
+		      sizeof(*res) * e820_table->nr_entries);
+	e820_res = res;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = e820_table->entries + i;
+
+		end = entry->addr + entry->size - 1;
+		if (end != (resource_size_t)end) {
+			res++;
+			continue;
+		}
+		res->start = entry->addr;
+		res->end   = end;
+		res->name  = e820_type_to_string(entry);
+		res->flags = e820_type_to_iomem_type(entry);
+		res->desc  = e820_type_to_iores_desc(entry);
+
+		/*
+		 * Don't register the region that could be conflicted with
+		 * PCI device BAR resources and insert them later in
+		 * pcibios_resource_survey():
+		 */
+		if (do_mark_busy(entry->type, res)) {
+			res->flags |= IORESOURCE_BUSY;
+			insert_resource(&iomem_resource, res);
+		}
+		res++;
+	}
+
+	/* Expose the bootloader-provided memory layout to the sysfs. */
+	for (i = 0; i < e820_table_firmware->nr_entries; i++) {
+		struct e820_entry *entry = e820_table_firmware->entries + i;
+
+		firmware_map_add_early(entry->addr, entry->addr + entry->size, e820_type_to_string(entry));
+	}
+}
+
+/*
+ * How much should we pad the end of RAM, depending on where it is?
+ */
+static unsigned long __init ram_alignment(resource_size_t pos)
+{
+	unsigned long mb = pos >> 20;
+
+	/* To 64kB in the first megabyte */
+	if (!mb)
+		return 64*1024;
+
+	/* To 1MB in the first 16MB */
+	if (mb < 16)
+		return 1024*1024;
+
+	/* To 64MB for anything above that */
+	return 64*1024*1024;
+}
+
+#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
+
+void __init e820__reserve_resources_late(void)
+{
+	int i;
+	struct resource *res;
+
+	res = e820_res;
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		if (!res->parent && res->end)
+			insert_resource_expand_to_fit(&iomem_resource, res);
+		res++;
+	}
+
+	/*
+	 * Try to bump up RAM regions to reasonable boundaries, to
+	 * avoid stolen RAM:
+	 */
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+		u64 start, end;
+
+		if (entry->type != E820_TYPE_RAM)
+			continue;
+
+		start = entry->addr + entry->size;
+		end = round_up(start, ram_alignment(start)) - 1;
+		if (end > MAX_RESOURCE_SIZE)
+			end = MAX_RESOURCE_SIZE;
+		if (start >= end)
+			continue;
+
+		printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
+		reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
+	}
+}
+
+/*
+ * Pass the firmware (bootloader) E820 map to the kernel and process it:
+ */
+char *__init e820__memory_setup_default(void)
+{
+	char *who = "BIOS-e820";
+
+	/*
+	 * Try to copy the BIOS-supplied E820-map.
+	 *
+	 * Otherwise fake a memory map; one section from 0k->640k,
+	 * the next section from 1mb->appropriate_mem_k
+	 */
+	if (append_e820_table(boot_params.e820_table, boot_params.e820_entries) < 0) {
+		u64 mem_size;
+
+		/* Compare results from other methods and take the one that gives more RAM: */
+		if (boot_params.alt_mem_k < boot_params.screen_info.ext_mem_k) {
+			mem_size = boot_params.screen_info.ext_mem_k;
+			who = "BIOS-88";
+		} else {
+			mem_size = boot_params.alt_mem_k;
+			who = "BIOS-e801";
+		}
+
+		e820_table->nr_entries = 0;
+		e820__range_add(0, LOWMEMSIZE(), E820_TYPE_RAM);
+		e820__range_add(HIGH_MEMORY, mem_size << 10, E820_TYPE_RAM);
+	}
+
+	/* We just appended a lot of ranges, sanitize the table: */
+	e820__update_table(e820_table);
+
+	return who;
+}
+
+/*
+ * Calls e820__memory_setup_default() in essence to pick up the firmware/bootloader
+ * E820 map - with an optional platform quirk available for virtual platforms
+ * to override this method of boot environment processing:
+ */
+void __init e820__memory_setup(void)
+{
+	char *who;
+
+	/* This is a firmware interface ABI - make sure we don't break it: */
+	BUILD_BUG_ON(sizeof(struct boot_e820_entry) != 20);
+
+	who = x86_init.resources.memory_setup();
+
+	memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
+	memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+
+	pr_info("BIOS-provided physical RAM map:\n");
+	e820__print_table(who);
+}
+
+void __init e820__memblock_setup(void)
+{
+	int i;
+	u64 end;
+
+	/*
+	 * The bootstrap memblock region count maximum is 128 entries
+	 * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
+	 * than that - so allow memblock resizing.
+	 *
+	 * This is safe, because this call happens pretty late during x86 setup,
+	 * so we know about reserved memory regions already. (This is important
+	 * so that memblock resizing does no stomp over reserved areas.)
+	 */
+	memblock_allow_resize();
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *entry = &e820_table->entries[i];
+
+		end = entry->addr + entry->size;
+		if (end != (resource_size_t)end)
+			continue;
+
+		if (entry->type == E820_TYPE_SOFT_RESERVED)
+			memblock_reserve(entry->addr, entry->size);
+
+		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
+			continue;
+
+		memblock_add(entry->addr, entry->size);
+	}
+
+	/* Throw away partial pages: */
+	memblock_trim_memory(PAGE_SIZE);
+
+	memblock_dump_all();
+}