davidlt/kernel-ark
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
904541e2f7
kernel-ark/arch/x86/kernel/e820_64.c
Alexander van Heukelum 320a6b2efc x86: reserve end-of-conventional-memory to 1MB, 64-bit 
This patch is an add-on to the 64-bit ebda patch. It makes
the functions reserve_ebda_region (renamed from reserve_ebda)
and copy_e820_map equal to the 32-bit versions of the previous
patch.

Changes:

Use u64 and u32 for local variables in copy_e820_map.

The amount of conventional memory and the start of the EBDA are
detected by reading the BIOS data area directly. Paravirtual
environments do not provide this area, so we bail out early
in that case. They will just have to set up a correct memory
map to start with.

Add a safety net for zeroed out BIOS data area.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 17:40:52 +02:00

855 lines
21 KiB
C
Raw Blame History

/*
* 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/suspend.h>
#include <linux/pfn.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/kdebug.h>
struct e820map e820;
/*
* 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.
*/
static unsigned long __initdata end_user_pfn = MAXMEM>>PAGE_SHIFT;
/*
* Early reserved memory areas.
*/
#define MAX_EARLY_RES 20
struct early_res {
unsigned long start, end;
char name[16];
};
static struct early_res early_res[MAX_EARLY_RES] __initdata = {
{ 0, PAGE_SIZE, "BIOS data page" }, /* BIOS data page */
#ifdef CONFIG_SMP
{ SMP_TRAMPOLINE_BASE, SMP_TRAMPOLINE_BASE + 2*PAGE_SIZE, "SMP_TRAMPOLINE" },
#endif
{}
};
void __init reserve_early(unsigned long start, unsigned long end, char *name)
{
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)
panic("Overlapping early reservations %lx-%lx %s to %lx-%lx %s\n",
start, end - 1, name?name:"", r->start, r->end - 1, r->name);
}
if (i >= MAX_EARLY_RES)
panic("Too many early reservations");
r = &early_res[i];
r->start = start;
r->end = end;
if (name)
strncpy(r->name, name, sizeof(r->name) - 1);
}
void __init early_res_to_bootmem(void)
{
int i;
for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
struct early_res *r = &early_res[i];
printk(KERN_INFO "early res: %d [%lx-%lx] %s\n", i,
r->start, r->end - 1, r->name);
reserve_bootmem_generic(r->start, r->end - r->start);
}
}
/* Check for already reserved areas */
static inline int
bad_addr(unsigned long *addrp, unsigned long size, unsigned long align)
{
int i;
unsigned long addr = *addrp, last;
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->end) {
*addrp = addr = round_up(r->end, align);
changed = 1;
goto again;
}
}
return changed;
}
/*
* This function checks if any part of the range <start,end> is mapped
* with type.
*/
int
e820_any_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;
}
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(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;
/* 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;
}
/*
* Find a free area with specified alignment in a specific range.
*/
unsigned long __init find_e820_area(unsigned long start, unsigned long end,
unsigned long size, unsigned long align)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
unsigned long addr, last;
unsigned long 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 -1UL;
}
/*
* Find the highest page frame number we have available
*/
unsigned long __init e820_end_of_ram(void)
{
unsigned long end_pfn;
end_pfn = find_max_pfn_with_active_regions();
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;
printk(KERN_INFO "end_pfn_map = %lu\n", 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;
insert_resource(&iomem_resource, res);
}
}
/*
* Find the ranges of physical addresses that do not correspond to
* e820 RAM areas and mark the corresponding pages as nosave for software
* suspend and suspend to RAM.
*
* 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(void)
{
int i;
unsigned long paddr;
paddr = round_down(e820.map[0].addr + e820.map[0].size, PAGE_SIZE);
for (i = 1; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
if (paddr < ei->addr)
register_nosave_region(PFN_DOWN(paddr),
PFN_UP(ei->addr));
paddr = round_down(ei->addr + ei->size, PAGE_SIZE);
if (ei->type != E820_RAM)
register_nosave_region(PFN_UP(ei->addr),
PFN_DOWN(paddr));
if (paddr >= (end_pfn << PAGE_SHIFT))
break;
}
}
/*
* Finds an active region in the address range from start_pfn to end_pfn and
* returns its range in ei_startpfn and ei_endpfn for the e820 entry.
*/
static int __init e820_find_active_region(const struct e820entry *ei,
unsigned long start_pfn,
unsigned long end_pfn,
unsigned long *ei_startpfn,
unsigned long *ei_endpfn)
{
*ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;
*ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT;
/* Skip map entries smaller than a page */
if (*ei_startpfn >= *ei_endpfn)
return 0;
/* Check if end_pfn_map should be updated */
if (ei->type != E820_RAM && *ei_endpfn > end_pfn_map)
end_pfn_map = *ei_endpfn;
/* Skip if map is outside the node */
if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||
*ei_startpfn >= end_pfn)
return 0;
/* Check for overlaps */
if (*ei_startpfn < start_pfn)
*ei_startpfn = start_pfn;
if (*ei_endpfn > end_pfn)
*ei_endpfn = end_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 end_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, end_pfn,
&ei_startpfn, &ei_endpfn))
add_active_range(nid, ei_startpfn, ei_endpfn);
}
/*
* 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++;
}
/*
* 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
*/
unsigned long __init e820_hole_size(unsigned long start, unsigned long end)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long end_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, end_pfn,
&ei_startpfn, &ei_endpfn))
ram += ei_endpfn - ei_startpfn;
}
return end - start - (ram << PAGE_SHIFT);
}
static 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.
*
*/
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++) {
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 >= E820MAX)
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.
*/
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 {
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;
}
static void early_panic(char *msg)
{
early_printk(msg);
panic(msg);
}
/* We're not void only for x86 32-bit compat */
char * __init machine_specific_memory_setup(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(boot_params.e820_map, &boot_params.e820_entries);
if (copy_e820_map(boot_params.e820_map, boot_params.e820_entries) < 0)
early_panic("Cannot find a valid memory map");
printk(KERN_INFO "BIOS-provided physical RAM map:\n");
e820_print_map(who);
/* In case someone cares... */
return who;
}
static int __init parse_memopt(char *p)
{
if (!p)
return -EINVAL;
end_user_pfn = memparse(p, &p);
end_user_pfn >>= PAGE_SHIFT;
return 0;
}
early_param("mem", parse_memopt);
static int userdef __initdata;
static int __init parse_memmap_opt(char *p)
{
char *oldp;
unsigned long long start_at, mem_size;
if (!strcmp(p, "exactmap")) {
#ifdef CONFIG_CRASH_DUMP
/*
* If we are doing a crash dump, we still need to know
* the real mem size before original memory map is
* reset.
*/
e820_register_active_regions(0, 0, -1UL);
saved_max_pfn = e820_end_of_ram();
remove_all_active_ranges();
#endif
end_pfn_map = 0;
e820.nr_map = 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);
add_memory_region(start_at, mem_size, E820_RAM);
} else if (*p == '#') {
start_at = memparse(p+1, &p);
add_memory_region(start_at, mem_size, E820_ACPI);
} else if (*p == '$') {
start_at = memparse(p+1, &p);
add_memory_region(start_at, mem_size, E820_RESERVED);
} else {
end_user_pfn = (mem_size >> PAGE_SHIFT);
}
return *p == '\0' ? 0 : -EINVAL;
}
early_param("memmap", parse_memmap_opt);
void __init finish_e820_parsing(void)
{
if (userdef) {
char nr = e820.nr_map;
if (sanitize_e820_map(e820.map, &nr) < 0)
early_panic("Invalid user supplied memory map");
e820.nr_map = nr;
printk(KERN_INFO "user-defined physical RAM map:\n");
e820_print_map("user");
}
}
void __init update_memory_range(u64 start, u64 size, unsigned old_type,
unsigned new_type)
{
int i;
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->size <= size) {
ei->type = new_type;
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);
}
}
void __init update_e820(void)
{
u8 nr_map;
nr_map = e820.nr_map;
if (sanitize_e820_map(e820.map, &nr_map))
return;
e820.nr_map = nr_map;
printk(KERN_INFO "modified physical RAM map:\n");
e820_print_map("modified");
}
unsigned long pci_mem_start = 0xaeedbabe;
EXPORT_SYMBOL(pci_mem_start);
/*
* 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 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");
}
/*
* 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);
}
int __init arch_get_ram_range(int slot, u64 *addr, u64 *size)
{
int i;
if (slot < 0 || slot >= e820.nr_map)
return -1;
for (i = slot; i < e820.nr_map; i++) {
if (e820.map[i].type != E820_RAM)
continue;
break;
}
if (i == e820.nr_map || e820.map[i].addr > (max_pfn << PAGE_SHIFT))
return -1;
*addr = e820.map[i].addr;
*size = min_t(u64, e820.map[i].size + e820.map[i].addr,
max_pfn << PAGE_SHIFT) - *addr;
return i + 1;
}
Reference in New Issue View Git Blame Copy Permalink