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OpenCloudOS-Kernel/arch/x86/kernel/e820.c

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/*
* 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/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/crash_dump.h>
#include <linux/export.h>
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <linux/firmware-map.h>
#include <linux/memblock.h>
#include <linux/sort.h>
#include <asm/e820/api.h>
#include <asm/proto.h>
#include <asm/setup.h>
#include <asm/cpufeature.h>
/*
* We organize the E820 table into two main data structures:
*
* - 'e820_table_firmware': the original firmware version passed to us by the
* bootloader - not modified by the kernel. 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.
*
* - 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_firmware_init __initdata;
struct e820_table *e820_table __refdata = &e820_table_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.
*/
int e820__mapped_any(u64 start, u64 end, unsigned 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;
if (entry->addr >= end || entry->addr + entry->size <= start)
continue;
return 1;
}
return 0;
}
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.
*/
int __init e820__mapped_all(u64 start, u64 end, unsigned 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 1;
}
return 0;
}
/*
* Add a memory region to the kernel E820 map.
*/
static void __init __e820_add_region(struct e820_table *table, u64 start, u64 size, int type)
{
int x = table->nr_entries;
if (x >= ARRAY_SIZE(table->entries)) {
pr_err("e820: 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_add_region(u64 start, u64 size, int type)
{
__e820_add_region(e820_table, start, size, type);
}
static void __init e820_print_type(u32 type)
{
switch (type) {
case E820_RAM: /* Fall through: */
case E820_RESERVED_KERN: pr_cont("usable"); break;
case E820_RESERVED: pr_cont("reserved"); break;
case E820_ACPI: pr_cont("ACPI data"); break;
case E820_NVS: pr_cont("ACPI NVS"); break;
case E820_UNUSABLE: pr_cont("unusable"); break;
case E820_PMEM: /* Fall through: */
case E820_PRAM: pr_cont("persistent (type %u)", type); break;
default: pr_cont("type %u", type); break;
}
}
void __init e820_print_map(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 the BIOS E820 map.
*
* Some E820 responses 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 biosmap points to an array of 'struct
* e820_entry' which on entry has elements in the range [0, *pnr_map)
* valid, and which has space for up to max_nr_map entries.
* On return, the resulting sanitized E820 map entries will be in
* overwritten in the same location, starting at biosmap.
*
* The integer pointed to by pnr_map must be valid on entry (the
* current number of valid entries located at biosmap). If the
* sanitizing succeeds the *pnr_map will be updated with the new
* number of valid entries (something no more than max_nr_map).
*
* 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 BIOS entry: */
struct e820_entry *pbios;
/* Address for this change point: */
unsigned long long addr;
};
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->pbios->addr) - (bp->addr != bp->pbios->addr);
}
int __init e820__update_table(struct e820_entry *biosmap, int max_nr_map, u32 *pnr_map)
{
static struct change_member change_point_list[2*E820_X_MAX] __initdata;
static struct change_member *change_point[2*E820_X_MAX] __initdata;
static struct e820_entry *overlap_list[E820_X_MAX] __initdata;
static struct e820_entry new_bios[E820_X_MAX] __initdata;
unsigned long current_type, last_type;
unsigned long long last_addr;
int chgidx;
int overlap_entries;
int new_bios_entry;
int old_nr, new_nr, chg_nr;
int i;
/* If there's only one memory region, don't bother: */
if (*pnr_map < 2)
return -1;
old_nr = *pnr_map;
BUG_ON(old_nr > max_nr_map);
/* Bail out if we find any unreasonable addresses in the BIOS map: */
for (i = 0; i < old_nr; i++) {
if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
return -1;
}
/* Create pointers for initial change-point information (for sorting): */
for (i = 0; i < 2 * old_nr; i++)
change_point[i] = &change_point_list[i];
/*
* Record all known change-points (starting and ending addresses),
* omitting empty memory regions:
*/
chgidx = 0;
for (i = 0; i < old_nr; i++) {
if (biosmap[i].size != 0) {
change_point[chgidx]->addr = biosmap[i].addr;
change_point[chgidx++]->pbios = &biosmap[i];
change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
change_point[chgidx++]->pbios = &biosmap[i];
}
}
chg_nr = chgidx;
/* Sort change-point list by memory addresses (low -> high): */
sort(change_point, chg_nr, sizeof *change_point, cpcompare, NULL);
/* Create a new BIOS memory map, removing overlaps: */
overlap_entries = 0; /* Number of entries in the overlap table */
new_bios_entry = 0; /* Index for creating new bios 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 BIOS map: */
for (chgidx = 0; chgidx < chg_nr; chgidx++) {
/* Keep track of all overlapping BIOS entries */
if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr) {
/* Add map entry to overlap list (> 1 entry implies an overlap) */
overlap_list[overlap_entries++] = change_point[chgidx]->pbios;
} else {
/* Remove entry from list (order independent, so swap with last): */
for (i = 0; i < overlap_entries; i++) {
if (overlap_list[i] == change_point[chgidx]->pbios)
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 BIOS map based on this information: */
if (current_type != last_type || current_type == E820_PRAM) {
if (last_type != 0) {
new_bios[new_bios_entry].size = change_point[chgidx]->addr - last_addr;
/* Move forward only if the new size was non-zero: */
if (new_bios[new_bios_entry].size != 0)
/* No more space left for new BIOS entries? */
if (++new_bios_entry >= max_nr_map)
break;
}
if (current_type != 0) {
new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
new_bios[new_bios_entry].type = current_type;
last_addr = change_point[chgidx]->addr;
}
last_type = current_type;
}
}
/* Retain count for new BIOS entries: */
new_nr = new_bios_entry;
/* Copy new BIOS mapping into the original location: */
memcpy(biosmap, new_bios, new_nr*sizeof(struct e820_entry));
*pnr_map = new_nr;
return 0;
}
static int __init __append_e820_table(struct e820_entry *biosmap, int nr_map)
{
while (nr_map) {
u64 start = biosmap->addr;
u64 size = biosmap->size;
u64 end = start + size - 1;
u32 type = biosmap->type;
/* Ignore the entry on 64-bit overflow: */
if (start > end && likely(size))
return -1;
e820_add_region(start, size, type);
biosmap++;
nr_map--;
}
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 e820_entry *biosmap, int nr_map)
{
/* Only one memory region (or negative)? Ignore it */
if (nr_map < 2)
return -1;
return __append_e820_table(biosmap, nr_map);
}
static u64 __init
__e820_update_range(struct e820_table *table, u64 start, u64 size, unsigned old_type, unsigned 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;
pr_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_add_region(table, start, size, new_type);
__e820_add_region(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_add_region(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_update_range(u64 start, u64 size, unsigned old_type, unsigned new_type)
{
return __e820_update_range(e820_table, start, size, old_type, new_type);
}
static u64 __init e820_update_range_firmware(u64 start, u64 size, unsigned old_type, unsigned new_type)
{
return __e820_update_range(e820_table_firmware, start, size, old_type, new_type);
}
/* Remove a range of memory from the E820 table: */
u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type, int checktype)
{
int i;
u64 end;
u64 real_removed_size = 0;
if (size > (ULLONG_MAX - start))
size = ULLONG_MAX - start;
end = start + size;
pr_debug("e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
if (checktype)
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 (checktype && 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(struct e820_entry));
continue;
}
/* Is the new range completely covered? */
if (entry->addr < start && entry_end > end) {
e820_add_region(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->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries))
return;
pr_info("e820: modified physical RAM map:\n");
e820_print_map("modified");
}
static void __init e820__update_table_firmware(void)
{
e820__update_table(e820_table_firmware->entries, ARRAY_SIZE(e820_table_firmware->entries), &e820_table_firmware->nr_entries);
}
#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_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(
"e820: Cannot find an available gap in the 32-bit address range\n"
"e820: PCI devices with unassigned 32-bit BARs may not work!\n");
#else
gapstart = 0x10000000;
#endif
}
/*
* e820_reserve_resources_late protect stolen RAM already
*/
pci_mem_start = gapstart;
pr_info("e820: [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_firmware 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 = kmalloc(size, GFP_KERNEL);
BUG_ON(!n);
memcpy(n, e820_table, size);
e820_table = n;
size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
n = kmalloc(size, GFP_KERNEL);
BUG_ON(!n);
memcpy(n, e820_table_firmware, size);
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 e820_entry *extmap;
struct setup_data *sdata;
sdata = early_memremap(phys_addr, data_len);
entries = sdata->len / sizeof(struct e820_entry);
extmap = (struct e820_entry *)(sdata->data);
__append_e820_table(extmap, entries);
e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
early_memunmap(sdata, data_len);
pr_info("e820: extended physical RAM map:\n");
e820_print_map("extended");
}
/**
* Find the ranges of physical addresses that do not correspond to
* E820 RAM areas and mark 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_mark_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_RAM && entry->type != E820_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_mark_nvs_memory(void)
{
int i;
for (i = 0; i < e820_table->nr_entries; i++) {
struct e820_entry *entry = &e820_table->entries[i];
if (entry->type == E820_NVS)
acpi_nvs_register(entry->addr, entry->size);
}
return 0;
}
core_initcall(e820_mark_nvs_memory);
#endif
/*
* Allocate the requested number of bytes with the requsted alignment
* and return (the physical address) to the caller. Also register this
* range in the 'firmware' 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_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
if (addr) {
e820_update_range_firmware(addr, size, E820_RAM, E820_RESERVED);
pr_info("e820: update e820_table_firmware for e820__memblock_alloc_reserved()\n");
e820__update_table_firmware();
}
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, unsigned 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("e820: 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_RAM);
}
unsigned long __init e820_end_of_low_ram_pfn(void)
{
return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_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_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
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)) {
#ifdef CONFIG_CRASH_DUMP
/*
* If we are doing a crash dump, we still need to know
* the real memory size before the original memory map is
* reset.
*/
saved_max_pfn = e820_end_of_ram_pfn();
#endif
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_add_region(start_at, mem_size, E820_RAM);
} else if (*p == '#') {
start_at = memparse(p+1, &p);
e820_add_region(start_at, mem_size, E820_ACPI);
} else if (*p == '$') {
start_at = memparse(p+1, &p);
e820_add_region(start_at, mem_size, E820_RESERVED);
} else if (*p == '!') {
start_at = memparse(p+1, &p);
e820_add_region(start_at, mem_size, E820_PRAM);
} else {
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_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);
void __init e820_reserve_setup_data(void)
{
struct setup_data *data;
u64 pa_data;
pa_data = boot_params.hdr.setup_data;
if (!pa_data)
return;
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
e820_update_range(pa_data, sizeof(*data)+data->len, E820_RAM, E820_RESERVED_KERN);
pa_data = data->next;
early_memunmap(data, sizeof(*data));
}
e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table));
printk(KERN_INFO "extended physical RAM map:\n");
e820_print_map("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->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0)
early_panic("Invalid user supplied memory map");
pr_info("e820: user-defined physical RAM map:\n");
e820_print_map("user");
}
}
static const char *__init e820_type_to_string(int e820_type)
{
switch (e820_type) {
case E820_RESERVED_KERN: /* Fall-through: */
case E820_RAM: return "System RAM";
case E820_ACPI: return "ACPI Tables";
case E820_NVS: return "ACPI Non-volatile Storage";
case E820_UNUSABLE: return "Unusable memory";
case E820_PRAM: return "Persistent Memory (legacy)";
case E820_PMEM: return "Persistent Memory";
default: return "Reserved";
}
}
static unsigned long __init e820_type_to_iomem_type(int e820_type)
{
switch (e820_type) {
case E820_RESERVED_KERN: /* Fall-through: */
case E820_RAM: return IORESOURCE_SYSTEM_RAM;
case E820_ACPI: /* Fall-through: */
case E820_NVS: /* Fall-through: */
case E820_UNUSABLE: /* Fall-through: */
case E820_PRAM: /* Fall-through: */
case E820_PMEM: /* Fall-through: */
default: return IORESOURCE_MEM;
}
}
static unsigned long __init e820_type_to_iores_desc(int e820_type)
{
switch (e820_type) {
case E820_ACPI: return IORES_DESC_ACPI_TABLES;
case E820_NVS: return IORES_DESC_ACPI_NV_STORAGE;
case E820_PMEM: return IORES_DESC_PERSISTENT_MEMORY;
case E820_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
case E820_RESERVED_KERN: /* Fall-through: */
case E820_RAM: /* Fall-through: */
case E820_UNUSABLE: /* Fall-through: */
default: return IORES_DESC_NONE;
}
}
static bool __init do_mark_busy(u32 type, struct resource *res)
{
/* this is the legacy bios/dos rom-shadow + mmio region */
if (res->start < (1ULL<<20))
return true;
/*
* Treat persistent memory like device memory, i.e. reserve it
* for exclusive use of a driver
*/
switch (type) {
case E820_RESERVED:
case E820_PRAM:
case E820_PMEM:
return false;
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 = alloc_bootmem(sizeof(struct resource) * e820_table->nr_entries);
e820_res = res;
for (i = 0; i < e820_table->nr_entries; i++) {
end = e820_table->entries[i].addr + e820_table->entries[i].size - 1;
if (end != (resource_size_t)end) {
res++;
continue;
}
res->name = e820_type_to_string(e820_table->entries[i].type);
res->start = e820_table->entries[i].addr;
res->end = end;
res->flags = e820_type_to_iomem_type(e820_table->entries[i].type);
res->desc = e820_type_to_iores_desc(e820_table->entries[i].type);
/*
* don't register the region that could be conflicted with
* pci device BAR resource and insert them later in
* pcibios_resource_survey()
*/
if (do_mark_busy(e820_table->entries[i].type, res)) {
res->flags |= IORESOURCE_BUSY;
insert_resource(&iomem_resource, res);
}
res++;
}
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->type));
}
}
/* How much should we pad RAM ending 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_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;
pr_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";
u32 new_nr;
/*
* 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
*/
new_nr = boot_params.e820_entries;
e820__update_table(boot_params.e820_table, ARRAY_SIZE(boot_params.e820_table), &new_nr);
boot_params.e820_entries = new_nr;
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_add_region(0, LOWMEMSIZE(), E820_RAM);
e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
}
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;
who = x86_init.resources.memory_setup();
memcpy(e820_table_firmware, e820_table, sizeof(struct e820_table));
pr_info("e820: BIOS-provided physical RAM map:\n");
e820_print_map(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_RAM && entry->type != E820_RESERVED_KERN)
continue;
memblock_add(entry->addr, entry->size);
}
/* Throw away partial pages: */
memblock_trim_memory(PAGE_SIZE);
memblock_dump_all();
}
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