// 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 MD5
* fingerprint 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 itsmain 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