/*
* Handle the memory map.
* The functions here do the job until bootmem takes over.
* $Id: e820.c,v 1.4 2002/09/19 19:25:32 ak Exp $
*
* 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/config.h>
#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 <asm/page.h>
#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/bootsetup.h>
extern char _end[];
/*
* PFN of last memory page.
*/
unsigned long end_pfn;
/*
* end_pfn only includes RAM, while end_pfn_map includes all e820 entries.
* The direct mapping extends to end_pfn_map, so that we can directly access
* apertures, ACPI and other tables without having to play with fixmaps.
*/
unsigned long end_pfn_map;
/*
* Last pfn which the user wants to use.
*/
unsigned long end_user_pfn = MAXMEM>>PAGE_SHIFT;
extern struct resource code_resource, data_resource;
/* Check for some hardcoded bad areas that early boot is not allowed to touch */
static inline int bad_addr(unsigned long *addrp, unsigned long size)
{
unsigned long addr = *addrp, last = addr + size;
/* various gunk below that needed for SMP startup */
if (addr < 0x8000) {
*addrp = 0x8000;
return 1;
}
/* direct mapping tables of the kernel */
if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) {
*addrp = table_end << PAGE_SHIFT;
return 1;
}
/* initrd */
#ifdef CONFIG_BLK_DEV_INITRD
if (LOADER_TYPE && INITRD_START && last >= INITRD_START &&
addr < INITRD_START+INITRD_SIZE) {
*addrp = INITRD_START + INITRD_SIZE;
return 1;
}
#endif
/* kernel code + 640k memory hole (later should not be needed, but
be paranoid for now) */
if (last >= 640*1024 && addr < __pa_symbol(&_end)) {
*addrp = __pa_symbol(&_end);
return 1;
}
/* XXX ramdisk image here? */
return 0;
}
int __init e820_mapped(unsigned long start, unsigned long 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;
}
/*
* Find a free area in a specific range.
*/
unsigned long __init find_e820_area(unsigned long start, unsigned long end, unsigned size)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
unsigned long addr = ei->addr, last;
if (ei->type != E820_RAM)
continue;
if (addr < start)
addr = start;
if (addr > ei->addr + ei->size)
continue;
while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
;
last = addr + size;
if (last > ei->addr + ei->size)
continue;
if (last > end)
continue;
return addr;
}
return -1UL;
}
/*
* Free bootmem based on the e820 table for a node.
*/
void __init e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
unsigned long last, addr;
if (ei->type != E820_RAM ||
ei->addr+ei->size <= start ||
ei->addr > end)
continue;
addr = round_up(ei->addr, PAGE_SIZE);
if (addr < start)
addr = start;
last = round_down(ei->addr + ei->size, PAGE_SIZE);
if (last >= end)
last = end;
if (last > addr && last-addr >= PAGE_SIZE)
free_bootmem_node(pgdat, addr, last-addr);
}
}
/*
* Find the highest page frame number we have available
*/
unsigned long __init e820_end_of_ram(void)
{
int i;
unsigned long end_pfn = 0;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
unsigned long start, end;
start = round_up(ei->addr, PAGE_SIZE);
end = round_down(ei->addr + ei->size, PAGE_SIZE);
if (start >= end)
continue;
if (ei->type == E820_RAM) {
if (end > end_pfn<<PAGE_SHIFT)
end_pfn = end>>PAGE_SHIFT;
} else {
if (end > end_pfn_map<<PAGE_SHIFT)
end_pfn_map = end>>PAGE_SHIFT;
}
}
if (end_pfn > end_pfn_map)
end_pfn_map = end_pfn;
if (end_pfn_map > MAXMEM>>PAGE_SHIFT)
end_pfn_map = MAXMEM>>PAGE_SHIFT;
if (end_pfn > end_user_pfn)
end_pfn = end_user_pfn;
if (end_pfn > end_pfn_map)
end_pfn = end_pfn_map;
return end_pfn;
}
/*
* Mark e820 reserved areas as busy for the resource manager.
*/
void __init e820_reserve_resources(void)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct resource *res;
res = alloc_bootmem_low(sizeof(struct resource));
switch (e820.map[i].type) {
case E820_RAM: res->name = "System RAM"; break;
case E820_ACPI: res->name = "ACPI Tables"; break;
case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
default: res->name = "reserved";
}
res->start = e820.map[i].addr;
res->end = res->start + e820.map[i].size - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
request_resource(&iomem_resource, res);
if (e820.map[i].type == E820_RAM) {
/*
* We don't know which RAM region contains kernel data,
* so we try it repeatedly and let the resource manager
* test it.
*/
request_resource(res, &code_resource);
request_resource(res, &data_resource);
#ifdef CONFIG_KEXEC
request_resource(res, &crashk_res);
#endif
}
}
}
/*
* Add a memory region to the kernel e820 map.
*/
void __init add_memory_region(unsigned long start, unsigned long size, int type)
{
int x = e820.nr_map;
if (x == E820MAX) {
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(" %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("(usable)\n");
break;
case E820_RESERVED:
printk("(reserved)\n");
break;
case E820_ACPI:
printk("(ACPI data)\n");
break;
case E820_NVS:
printk("(ACPI NVS)\n");
break;
default: printk("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.
*
*/
static int __init sanitize_e820_map(struct e820entry * biosmap, char * 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*E820MAX] __initdata;
static struct change_member *change_point[2*E820MAX] __initdata;
static struct e820entry *overlap_list[E820MAX] __initdata;
static struct e820entry new_bios[E820MAX] __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;
/*
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_
*/
/* if there's only one memory region, don't bother */
if (*pnr_map < 2)
return -1;
old_nr = *pnr_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++) {
/* if <current_addr> > <last_addr>, swap */
/* or, if current=<start_addr> & last=<end_addr>, swap */
if ((change_point[i]->addr < change_point[i-1]->addr) ||
((change_point[i]->addr == change_point[i-1]->addr) &&
(change_point[i]->addr == change_point[i]->pbios->addr) &&
(change_point[i-1]->addr != change_point[i-1]->pbios->addr))
)
{
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)
if (++new_bios_entry >= E820MAX)
break; /* no more space left for new bios entries */
}
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;
}
}
new_nr = new_bios_entry; /* retain count for new bios entries */
/* 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.
*
* We check to see that the memory map contains at least 2 elements
* before we'll use it, because the detection code in setup.S may
* not be perfect and most every PC known to man has two memory
* regions: one from 0 to 640k, and one from 1mb up. (The IBM
* thinkpad 560x, for example, does not cooperate with the memory
* detection code.)
*/
static 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 {
unsigned long start = biosmap->addr;
unsigned long size = biosmap->size;
unsigned long end = start + size;
unsigned long type = biosmap->type;
/* Overflow in 64 bits? Ignore the memory map. */
if (start > end)
return -1;
/*
* Some BIOSes claim RAM in the 640k - 1M region.
* Not right. Fix it up.
*
* This should be removed on Hammer which is supposed to not
* have non e820 covered ISA mappings there, but I had some strange
* problems so it stays for now. -AK
*/
if (type == E820_RAM) {
if (start < 0x100000ULL && end > 0xA0000ULL) {
if (start < 0xA0000ULL)
add_memory_region(start, 0xA0000ULL-start, type);
if (end <= 0x100000ULL)
continue;
start = 0x100000ULL;
size = end - start;
}
}
add_memory_region(start, size, type);
} while (biosmap++,--nr_map);
return 0;
}
void __init setup_memory_region(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
*/
sanitize_e820_map(E820_MAP, &E820_MAP_NR);
if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
unsigned long mem_size;
/* compare results from other methods and take the greater */
if (ALT_MEM_K < EXT_MEM_K) {
mem_size = EXT_MEM_K;
who = "BIOS-88";
} else {
mem_size = ALT_MEM_K;
who = "BIOS-e801";
}
e820.nr_map = 0;
add_memory_region(0, LOWMEMSIZE(), E820_RAM);
add_memory_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
}
printk(KERN_INFO "BIOS-provided physical RAM map:\n");
e820_print_map(who);
}
void __init parse_memopt(char *p, char **from)
{
end_user_pfn = memparse(p, from);
end_user_pfn >>= PAGE_SHIFT;
}
unsigned long pci_mem_start = 0xaeedbabe;
/*
* 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;
unsigned 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;
}
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");
}
/*
* Start allocating dynamic PCI memory a bit into the gap,
* aligned up to the nearest megabyte.
*
* Question: should we try to pad it up a bit (do something
* like " + (gapsize >> 3)" in there too?). We now have the
* technology.
*/
pci_mem_start = (gapstart + 0xfffff) & ~0xfffff;
printk(KERN_INFO "Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
pci_mem_start, gapstart, gapsize);
}
