linux/arch/x86/kernel/e820.c
Ingo Molnar 640e1b38b0 x86/boot/e820: Basic cleanup of e820.c
Over the last decade or so e820.c has become an ureadable mess of
tinkerware. Perform some very basic cleanups before doing more
intricate cleanups, so that my eyes don't start bleeding when I look at it.

Here's some of the excesses:

 - Total disregard of countless aspects of Documentation/CodingStyle.

 - Totally inconsistent hodge-podge of various coding styles and practices.

 - Gems like:

       (unsigned long long) e820_table->entries[i].addr

   ... which is a completely unnecessary type conversion of an u64 value.

 - Incomprehensible comments while there are major functions with absolutely
   no explanation - plus an armada of typos and grammar mistakes.

 - Mindless checkpatch artifacts such as:

         if (append_e820_table(boot_params.e820_table, boot_params.e820_entries)
           < 0) {

           for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
                                   NULL) {

 - Actively misleading comments:

        /* In case someone cares... */
        return who;

   ( The usage site of the return value just a few lines further down makes it
     clear that we very much care about the return value, we use it to print
     out the e820 map... )

 - Colorfully inconsistent capitalization and punctuation throughout.

 - etc.

This patch fixes only the worst excesses - there's more to fix.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28 14:42:27 +01:00

1202 lines
32 KiB
C

/*
* 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_any_mapped(u64 start, u64 end, unsigned type)
{
int i;
for (i = 0; i < e820_table->nr_entries; i++) {
struct e820_entry *ei = &e820_table->entries[i];
if (type && ei->type != type)
continue;
if (ei->addr >= end || ei->addr + ei->size <= start)
continue;
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(e820_any_mapped);
/*
* 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_all_mapped(u64 start, u64 end, unsigned type)
{
int i;
for (i = 0; i < e820_table->nr_entries; i++) {
struct e820_entry *ei = &e820_table->entries[i];
if (type && ei->type != type)
continue;
/* Is the region (part) in overlap with the current region? */
if (ei->addr >= end || ei->addr + ei->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 (ei->addr <= start)
start = ei->addr + ei->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)) {
printk(KERN_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: printk(KERN_CONT "usable"); break;
case E820_RESERVED: printk(KERN_CONT "reserved"); break;
case E820_ACPI: printk(KERN_CONT "ACPI data"); break;
case E820_NVS: printk(KERN_CONT "ACPI NVS"); break;
case E820_UNUSABLE: printk(KERN_CONT "unusable"); break;
case E820_PMEM: /* Fall through: */
case E820_PRAM: printk(KERN_CONT "persistent (type %u)", type); break;
default: printk(KERN_CONT "type %u", type); break;
}
}
void __init e820_print_map(char *who)
{
int i;
for (i = 0; i < e820_table->nr_entries; i++) {
printk(KERN_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);
printk(KERN_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 sanitize_e820_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 sanitize_e820_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;
printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
e820_print_type(old_type);
printk(KERN_CONT " ==> ");
e820_print_type(new_type);
printk(KERN_CONT "\n");
for (i = 0; i < table->nr_entries; i++) {
struct e820_entry *ei = &table->entries[i];
u64 final_start, final_end;
u64 ei_end;
if (ei->type != old_type)
continue;
ei_end = ei->addr + ei->size;
/* Completely covered by new range? */
if (ei->addr >= start && ei_end <= end) {
ei->type = new_type;
real_updated_size += ei->size;
continue;
}
/* New range is completely covered? */
if (ei->addr < start && ei_end > end) {
__e820_add_region(table, start, size, new_type);
__e820_add_region(table, end, ei_end - end, ei->type);
ei->size = start - ei->addr;
real_updated_size += size;
continue;
}
/* Partially covered: */
final_start = max(start, ei->addr);
final_end = min(end, ei_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:
*/
ei->size -= final_end - final_start;
if (ei->addr < final_start)
continue;
ei->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;
printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
if (checktype)
e820_print_type(old_type);
printk(KERN_CONT "\n");
for (i = 0; i < e820_table->nr_entries; i++) {
struct e820_entry *ei = &e820_table->entries[i];
u64 final_start, final_end;
u64 ei_end;
if (checktype && ei->type != old_type)
continue;
ei_end = ei->addr + ei->size;
/* Completely covered? */
if (ei->addr >= start && ei_end <= end) {
real_removed_size += ei->size;
memset(ei, 0, sizeof(struct e820_entry));
continue;
}
/* Is the new range completely covered? */
if (ei->addr < start && ei_end > end) {
e820_add_region(end, ei_end - end, ei->type);
ei->size = start - ei->addr;
real_removed_size += size;
continue;
}
/* Partially covered: */
final_start = max(start, ei->addr);
final_end = min(end, ei_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:
*/
ei->size -= final_end - final_start;
if (ei->addr < final_start)
continue;
ei->addr = final_end;
}
return real_removed_size;
}
void __init update_e820(void)
{
if (sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries))
return;
printk(KERN_INFO "e820: modified physical RAM map:\n");
e820_print_map("modified");
}
static void __init update_e820_table_firmware(void)
{
sanitize_e820_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;
printk(KERN_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;
printk(KERN_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 parse_e820_ext(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);
sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
early_memunmap(sdata, data_len);
printk(KERN_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 *ei = &e820_table->entries[i];
if (pfn < PFN_UP(ei->addr))
register_nosave_region(pfn, PFN_UP(ei->addr));
pfn = PFN_DOWN(ei->addr + ei->size);
if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
register_nosave_region(PFN_UP(ei->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 *ei = &e820_table->entries[i];
if (ei->type == E820_NVS)
acpi_nvs_register(ei->addr, ei->size);
}
return 0;
}
core_initcall(e820_mark_nvs_memory);
#endif
/*
* pre allocated 4k and reserved it in memblock and e820_table_firmware
*/
u64 __init early_reserve_e820(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);
printk(KERN_INFO "e820: update e820_table_firmware for early_reserve_e820\n");
update_e820_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 *ei = &e820_table->entries[i];
unsigned long start_pfn;
unsigned long end_pfn;
if (ei->type != type)
continue;
start_pfn = ei->addr >> PAGE_SHIFT;
end_pfn = (ei->addr + ei->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;
printk(KERN_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
printk(KERN_WARNING "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 finish_e820_parsing(void)
{
if (userdef) {
if (sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0)
early_panic("Invalid user supplied memory map");
printk(KERN_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;
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";
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;
sanitize_e820_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));
printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
e820_print_map(who);
}
void __init memblock_x86_fill(void)
{
int i;
u64 end;
/*
* EFI may have more than 128 entries
* We are safe to enable resizing, beause memblock_x86_fill()
* is rather later for x86
*/
memblock_allow_resize();
for (i = 0; i < e820_table->nr_entries; i++) {
struct e820_entry *ei = &e820_table->entries[i];
end = ei->addr + ei->size;
if (end != (resource_size_t)end)
continue;
if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
continue;
memblock_add(ei->addr, ei->size);
}
/* throw away partial pages */
memblock_trim_memory(PAGE_SIZE);
memblock_dump_all();
}
void __init memblock_find_dma_reserve(void)
{
#ifdef CONFIG_X86_64
u64 nr_pages = 0, nr_free_pages = 0;
unsigned long start_pfn, end_pfn;
phys_addr_t start, end;
int i;
u64 u;
/*
* need to find out used area below MAX_DMA_PFN
* need to use memblock to get free size in [0, MAX_DMA_PFN]
* at first, and assume boot_mem will not take below MAX_DMA_PFN
*/
for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
start_pfn = min(start_pfn, MAX_DMA_PFN);
end_pfn = min(end_pfn, MAX_DMA_PFN);
nr_pages += end_pfn - start_pfn;
}
for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
if (start_pfn < end_pfn)
nr_free_pages += end_pfn - start_pfn;
}
set_dma_reserve(nr_pages - nr_free_pages);
#endif
}