android_kernel_xiaomi_sm7250/arch/x86_64/kernel/e820.c
Andi Kleen a1e9778203 [PATCH] x86_64: Port over e820 gap detection from i386
Look for gaps in the e820 memory map to put PCI resources in.

This hopefully fixes problems with the PCI code assigning 32bit BARs MMIO
resources which are >32bit.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16 15:25:12 -07:00

573 lines
15 KiB
C

/*
* 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 $
*/
#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 <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;
if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
continue;
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);
}
}
}
/*
* 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;
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) */
chgidx = 0;
for (i=0; i < old_nr; i++) {
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];
}
/* sort change-point list by memory addresses (low -> high) */
still_changing = 1;
while (still_changing) {
still_changing = 0;
for (i=1; i < 2*old_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 < 2*old_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);
}