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

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/*
* Handle the memory map.
* The functions here do the job until bootmem takes over.
*
* Getting sanitize_e820_map() in sync with i386 version by applying change:
* - Provisions for empty E820 memory regions (reported by certain BIOSes).
* Alex Achenbach <xela@slit.de>, December 2002.
* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
*
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/string.h>
#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pfn.h>
#include <linux/suspend.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/setup.h>
#include <asm/trampoline.h>
struct e820map e820;
/* 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.nr_map; i++) {
struct e820entry *ei = &e820.map[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 range <start,end> is mapped with type.
*
* Note: this function only works correct if the e820 table is sorted and
* not-overlapping, which is the case
*/
int __init e820_all_mapped(u64 start, u64 end, unsigned type)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[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
*/
if (start >= end)
return 1;
}
return 0;
}
/*
* Add a memory region to the kernel e820 map.
*/
void __init add_memory_region(u64 start, u64 size, int type)
{
int x = e820.nr_map;
if (x == ARRAY_SIZE(e820.map)) {
printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
return;
}
e820.map[x].addr = start;
e820.map[x].size = size;
e820.map[x].type = type;
e820.nr_map++;
}
void __init e820_print_map(char *who)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
printk(KERN_INFO " %s: %016Lx - %016Lx ", who,
(unsigned long long) e820.map[i].addr,
(unsigned long long)
(e820.map[i].addr + e820.map[i].size));
switch (e820.map[i].type) {
case E820_RAM:
printk(KERN_CONT "(usable)\n");
break;
case E820_RESERVED:
printk(KERN_CONT "(reserved)\n");
break;
case E820_ACPI:
printk(KERN_CONT "(ACPI data)\n");
break;
case E820_NVS:
printk(KERN_CONT "(ACPI NVS)\n");
break;
default:
printk(KERN_CONT "type %u\n", e820.map[i].type);
break;
}
}
}
/*
* 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
* e820entry' 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) and will
* be updated on return, with the new number of valid entries
* (something no more than max_nr_map.)
*
* The return value from sanitize_e820_map() 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_
*/
int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
int *pnr_map)
{
struct change_member {
struct e820entry *pbios; /* pointer to original bios entry */
unsigned long long addr; /* address for this change point */
};
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 e820entry *overlap_list[E820_X_MAX] __initdata;
static struct e820entry new_bios[E820_X_MAX] __initdata;
struct change_member *change_tmp;
unsigned long current_type, last_type;
unsigned long long last_addr;
int chgidx, still_changing;
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 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 those that are for 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) */
still_changing = 1;
while (still_changing) {
still_changing = 0;
for (i = 1; i < chg_nr; i++) {
unsigned long long curaddr, lastaddr;
unsigned long long curpbaddr, lastpbaddr;
curaddr = change_point[i]->addr;
lastaddr = change_point[i - 1]->addr;
curpbaddr = change_point[i]->pbios->addr;
lastpbaddr = change_point[i - 1]->pbios->addr;
/*
* swap entries, when:
*
* curaddr > lastaddr or
* curaddr == lastaddr and curaddr == curpbaddr and
* lastaddr != lastpbaddr
*/
if (curaddr < lastaddr ||
(curaddr == lastaddr && curaddr == curpbaddr &&
lastaddr != lastpbaddr)) {
change_tmp = change_point[i];
change_point[i] = change_point[i-1];
change_point[i-1] = change_tmp;
still_changing = 1;
}
}
}
/* 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 affect 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) {
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 original location */
memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
*pnr_map = new_nr;
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.
*/
int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
{
/* Only one memory region (or negative)? Ignore it */
if (nr_map < 2)
return -1;
do {
u64 start = biosmap->addr;
u64 size = biosmap->size;
u64 end = start + size;
u32 type = biosmap->type;
/* Overflow in 64 bits? Ignore the memory map. */
if (start > end)
return -1;
add_memory_region(start, size, type);
} while (biosmap++, --nr_map);
return 0;
}
u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
unsigned new_type)
{
int i;
u64 real_updated_size = 0;
BUG_ON(old_type == new_type);
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
u64 final_start, final_end;
if (ei->type != old_type)
continue;
/* totally covered? */
if (ei->addr >= start &&
(ei->addr + ei->size) <= (start + size)) {
ei->type = new_type;
real_updated_size += ei->size;
continue;
}
/* partially covered */
final_start = max(start, ei->addr);
final_end = min(start + size, ei->addr + ei->size);
if (final_start >= final_end)
continue;
add_memory_region(final_start, final_end - final_start,
new_type);
real_updated_size += final_end - final_start;
}
return real_updated_size;
}
void __init update_e820(void)
{
int nr_map;
nr_map = e820.nr_map;
if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
return;
e820.nr_map = nr_map;
printk(KERN_INFO "modified physical RAM map:\n");
e820_print_map("modified");
}
/*
* Search for the biggest gap in the low 32 bits of the e820
* memory space. We pass this space to PCI to 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, round;
unsigned long long last;
int i;
int found = 0;
last = 0x100000000ull;
gapstart = 0x10000000;
gapsize = 0x400000;
i = e820.nr_map;
while (--i >= 0) {
unsigned long long start = e820.map[i].addr;
unsigned long long end = start + e820.map[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;
}
#ifdef CONFIG_X86_64
if (!found) {
gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
"address range\n"
KERN_ERR "PCI: Unassigned devices with 32bit resource "
"registers may break!\n");
}
#endif
/*
* See how much we want to round up: start off with
* rounding to the next 1MB area.
*/
round = 0x100000;
while ((gapsize >> 4) > round)
round += round;
/* Fun with two's complement */
pci_mem_start = (gapstart + round) & -round;
printk(KERN_INFO
"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
pci_mem_start, gapstart, gapsize);
}
#if defined(CONFIG_X86_64) || \
(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
/**
* 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 and assumes the first e820 area to be RAM.
*/
void __init e820_mark_nosave_regions(unsigned long limit_pfn)
{
int i;
unsigned long pfn;
pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
for (i = 1; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[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)
register_nosave_region(PFN_UP(ei->addr), pfn);
if (pfn >= limit_pfn)
break;
}
}
#endif
/*
* Early reserved memory areas.
*/
#define MAX_EARLY_RES 20
struct early_res {
u64 start, end;
char name[16];
};
static struct early_res early_res[MAX_EARLY_RES] __initdata = {
{ 0, PAGE_SIZE, "BIOS data page" }, /* BIOS data page */
#if defined(CONFIG_X86_64) && defined(CONFIG_X86_TRAMPOLINE)
{ TRAMPOLINE_BASE, TRAMPOLINE_BASE + 2 * PAGE_SIZE, "TRAMPOLINE" },
#endif
#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
/*
* But first pinch a few for the stack/trampoline stuff
* FIXME: Don't need the extra page at 4K, but need to fix
* trampoline before removing it. (see the GDT stuff)
*/
{ PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE" },
/*
* Has to be in very low memory so we can execute
* real-mode AP code.
*/
{ TRAMPOLINE_BASE, TRAMPOLINE_BASE + PAGE_SIZE, "TRAMPOLINE" },
#endif
{}
};
static int __init find_overlapped_early(u64 start, u64 end)
{
int i;
struct early_res *r;
for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
r = &early_res[i];
if (end > r->start && start < r->end)
break;
}
return i;
}
void __init reserve_early(u64 start, u64 end, char *name)
{
int i;
struct early_res *r;
i = find_overlapped_early(start, end);
if (i >= MAX_EARLY_RES)
panic("Too many early reservations");
r = &early_res[i];
if (r->end)
panic("Overlapping early reservations "
"%llx-%llx %s to %llx-%llx %s\n",
start, end - 1, name?name:"", r->start,
r->end - 1, r->name);
r->start = start;
r->end = end;
if (name)
strncpy(r->name, name, sizeof(r->name) - 1);
}
void __init free_early(u64 start, u64 end)
{
struct early_res *r;
int i, j;
i = find_overlapped_early(start, end);
r = &early_res[i];
if (i >= MAX_EARLY_RES || r->end != end || r->start != start)
panic("free_early on not reserved area: %llx-%llx!",
start, end - 1);
for (j = i + 1; j < MAX_EARLY_RES && early_res[j].end; j++)
;
memmove(&early_res[i], &early_res[i + 1],
(j - 1 - i) * sizeof(struct early_res));
early_res[j - 1].end = 0;
}
int __init page_is_reserved_early(unsigned long pagenr)
{
u64 start = (u64)pagenr << PAGE_SHIFT;
int i;
struct early_res *r;
i = find_overlapped_early(start, start + PAGE_SIZE);
r = &early_res[i];
return (i < MAX_EARLY_RES && r->end);
}
void __init early_res_to_bootmem(u64 start, u64 end)
{
int i;
u64 final_start, final_end;
for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
struct early_res *r = &early_res[i];
final_start = max(start, r->start);
final_end = min(end, r->end);
if (final_start >= final_end)
continue;
printk(KERN_INFO " early res: %d [%llx-%llx] %s\n", i,
final_start, final_end - 1, r->name);
reserve_bootmem(final_start, final_end - final_start,
BOOTMEM_DEFAULT);
}
}
/* Check for already reserved areas */
static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
{
int i;
u64 addr = *addrp;
int changed = 0;
struct early_res *r;
again:
i = find_overlapped_early(addr, addr + size);
r = &early_res[i];
if (i < MAX_EARLY_RES && r->end) {
*addrp = addr = round_up(r->end, align);
changed = 1;
goto again;
}
return changed;
}
/* Check for already reserved areas */
static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
{
int i;
u64 addr = *addrp, last;
u64 size = *sizep;
int changed = 0;
again:
last = addr + size;
for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
struct early_res *r = &early_res[i];
if (last > r->start && addr < r->start) {
size = r->start - addr;
changed = 1;
goto again;
}
if (last > r->end && addr < r->end) {
addr = round_up(r->end, align);
size = last - addr;
changed = 1;
goto again;
}
if (last <= r->end && addr >= r->start) {
(*sizep)++;
return 0;
}
}
if (changed) {
*addrp = addr;
*sizep = size;
}
return changed;
}
/*
* Find a free area with specified alignment in a specific range.
*/
u64 __init find_e820_area(u64 start, u64 end, u64 size, u64 align)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
u64 addr, last;
u64 ei_last;
if (ei->type != E820_RAM)
continue;
addr = round_up(ei->addr, align);
ei_last = ei->addr + ei->size;
if (addr < start)
addr = round_up(start, align);
if (addr >= ei_last)
continue;
while (bad_addr(&addr, size, align) && addr+size <= ei_last)
;
last = addr + size;
if (last > ei_last)
continue;
if (last > end)
continue;
return addr;
}
return -1ULL;
}
/*
* Find next free range after *start
*/
u64 __init find_e820_area_size(u64 start, u64 *sizep, u64 align)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
u64 addr, last;
u64 ei_last;
if (ei->type != E820_RAM)
continue;
addr = round_up(ei->addr, align);
ei_last = ei->addr + ei->size;
if (addr < start)
addr = round_up(start, align);
if (addr >= ei_last)
continue;
*sizep = ei_last - addr;
while (bad_addr_size(&addr, sizep, align) &&
addr + *sizep <= ei_last)
;
last = addr + *sizep;
if (last > ei_last)
continue;
return addr;
}
return -1UL;
}
/*
* pre allocated 4k and reserved it in e820
*/
u64 __init early_reserve_e820(u64 startt, u64 sizet, u64 align)
{
u64 size = 0;
u64 addr;
u64 start;
start = startt;
while (size < sizet)
start = find_e820_area_size(start, &size, align);
if (size < sizet)
return 0;
addr = round_down(start + size - sizet, align);
update_memory_range(addr, sizet, E820_RAM, E820_RESERVED);
printk(KERN_INFO "update e820 for early_reserve_e820\n");
update_e820();
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
/*
* Last pfn which the user wants to use.
*/
unsigned long __initdata end_user_pfn = MAX_ARCH_PFN;
/*
* Find the highest page frame number we have available
*/
unsigned long __init e820_end_of_ram(void)
{
unsigned long last_pfn;
unsigned long max_arch_pfn = MAX_ARCH_PFN;
last_pfn = find_max_pfn_with_active_regions();
if (last_pfn > max_arch_pfn)
last_pfn = max_arch_pfn;
if (last_pfn > end_user_pfn)
last_pfn = end_user_pfn;
printk(KERN_INFO "last_pfn = %lu max_arch_pfn = %lu\n",
last_pfn, max_arch_pfn);
return last_pfn;
}
/*
* Finds an active region in the address range from start_pfn to last_pfn and
* returns its range in ei_startpfn and ei_endpfn for the e820 entry.
*/
int __init e820_find_active_region(const struct e820entry *ei,
unsigned long start_pfn,
unsigned long last_pfn,
unsigned long *ei_startpfn,
unsigned long *ei_endpfn)
{
u64 align = PAGE_SIZE;
*ei_startpfn = round_up(ei->addr, align) >> PAGE_SHIFT;
*ei_endpfn = round_down(ei->addr + ei->size, align) >> PAGE_SHIFT;
/* Skip map entries smaller than a page */
if (*ei_startpfn >= *ei_endpfn)
return 0;
/* Skip if map is outside the node */
if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
*ei_startpfn >= last_pfn)
return 0;
/* Check for overlaps */
if (*ei_startpfn < start_pfn)
*ei_startpfn = start_pfn;
if (*ei_endpfn > last_pfn)
*ei_endpfn = last_pfn;
/* Obey end_user_pfn to save on memmap */
if (*ei_startpfn >= end_user_pfn)
return 0;
if (*ei_endpfn > end_user_pfn)
*ei_endpfn = end_user_pfn;
return 1;
}
/* Walk the e820 map and register active regions within a node */
void __init e820_register_active_regions(int nid, unsigned long start_pfn,
unsigned long last_pfn)
{
unsigned long ei_startpfn;
unsigned long ei_endpfn;
int i;
for (i = 0; i < e820.nr_map; i++)
if (e820_find_active_region(&e820.map[i],
start_pfn, last_pfn,
&ei_startpfn, &ei_endpfn))
add_active_range(nid, ei_startpfn, ei_endpfn);
}
/*
* Find the hole size (in bytes) in the memory range.
* @start: starting address of the memory range to scan
* @end: ending address of the memory range to scan
*/
u64 __init e820_hole_size(u64 start, u64 end)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long last_pfn = end >> PAGE_SHIFT;
unsigned long ei_startpfn, ei_endpfn, ram = 0;
int i;
for (i = 0; i < e820.nr_map; i++) {
if (e820_find_active_region(&e820.map[i],
start_pfn, last_pfn,
&ei_startpfn, &ei_endpfn))
ram += ei_endpfn - ei_startpfn;
}
return end - start - ((u64)ram << PAGE_SHIFT);
}
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