linux/arch/x86/kernel/e820.c
Linus Torvalds 88793e5c77 The libnvdimm sub-system introduces, in addition to the libnvdimm-core,
4 drivers / enabling modules:
 
 NFIT:
 Instantiates an "nvdimm bus" with the core and registers memory devices
 (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware Interface
 table).  After registering NVDIMMs the NFIT driver then registers
 "region" devices.  A libnvdimm-region defines an access mode and the
 boundaries of persistent memory media.  A region may span multiple
 NVDIMMs that are interleaved by the hardware memory controller.  In
 turn, a libnvdimm-region can be carved into a "namespace" device and
 bound to the PMEM or BLK driver which will attach a Linux block device
 (disk) interface to the memory.
 
 PMEM:
 Initially merged in v4.1 this driver for contiguous spans of persistent
 memory address ranges is re-worked to drive PMEM-namespaces emitted by
 the libnvdimm-core.  In this update the PMEM driver, on x86, gains the
 ability to assert that writes to persistent memory have been flushed all
 the way through the caches and buffers in the platform to persistent
 media.  See memcpy_to_pmem() and wmb_pmem().
 
 BLK:
 This new driver enables access to persistent memory media through "Block
 Data Windows" as defined by the NFIT.  The primary difference of this
 driver to PMEM is that only a small window of persistent memory is
 mapped into system address space at any given point in time.  Per-NVDIMM
 windows are reprogrammed at run time, per-I/O, to access different
 portions of the media.  BLK-mode, by definition, does not support DAX.
 
 BTT:
 This is a library, optionally consumed by either PMEM or BLK, that
 converts a byte-accessible namespace into a disk with atomic sector
 update semantics (prevents sector tearing on crash or power loss).  The
 sinister aspect of sector tearing is that most applications do not know
 they have a atomic sector dependency.  At least today's disk's rarely
 ever tear sectors and if they do one almost certainly gets a CRC error
 on access.  NVDIMMs will always tear and always silently.  Until an
 application is audited to be robust in the presence of sector-tearing
 the usage of BTT is recommended.
 
 Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
 Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
 Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
 Wysocki, and Bob Moore.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVjZGBAAoJEB7SkWpmfYgC4fkP/j+k6HmSRNU/yRYPyo7CAWvj
 3P5P1i6R6nMZZbjQrQArAXaIyLlFk4sEQDYsciR6dmslhhFZAkR2eFwVO5rBOyx3
 QN0yxEpyjJbroRFUrV/BLaFK4cq2oyJAFFHs0u7/pLHBJ4MDMqfRKAMtlnBxEkTE
 LFcqXapSlvWitSbjMdIBWKFEvncaiJ2mdsFqT4aZqclBBTj00eWQvEG9WxleJLdv
 +tj7qR/vGcwOb12X5UrbQXgwtMYos7A6IzhHbqwQL8IrOcJ6YB8NopJUpLDd7ZVq
 KAzX6ZYMzNueN4uvv6aDfqDRLyVL7qoxM9XIjGF5R8SV9sF2LMspm1FBpfowo1GT
 h2QMr0ky1nHVT32yspBCpE9zW/mubRIDtXxEmZZ53DIc4N6Dy9jFaNVmhoWtTAqG
 b9pndFnjUzzieCjX5pCvo2M5U6N0AQwsnq76/CasiWyhSa9DNKOg8MVDRg0rbxb0
 UvK0v8JwOCIRcfO3qiKcx+02nKPtjCtHSPqGkFKPySRvAdb+3g6YR26CxTb3VmnF
 etowLiKU7HHalLvqGFOlDoQG6viWes9Zl+ZeANBOCVa6rL2O7ZnXJtYgXf1wDQee
 fzgKB78BcDjXH4jHobbp/WBANQGN/GF34lse8yHa7Ym+28uEihDvSD1wyNLnefmo
 7PJBbN5M5qP5tD0aO7SZ
 =VtWG
 -----END PGP SIGNATURE-----

Merge tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm

Pull libnvdimm subsystem from Dan Williams:
 "The libnvdimm sub-system introduces, in addition to the
  libnvdimm-core, 4 drivers / enabling modules:

  NFIT:
    Instantiates an "nvdimm bus" with the core and registers memory
    devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware
    Interface table).

    After registering NVDIMMs the NFIT driver then registers "region"
    devices.  A libnvdimm-region defines an access mode and the
    boundaries of persistent memory media.  A region may span multiple
    NVDIMMs that are interleaved by the hardware memory controller.  In
    turn, a libnvdimm-region can be carved into a "namespace" device and
    bound to the PMEM or BLK driver which will attach a Linux block
    device (disk) interface to the memory.

  PMEM:
    Initially merged in v4.1 this driver for contiguous spans of
    persistent memory address ranges is re-worked to drive
    PMEM-namespaces emitted by the libnvdimm-core.

    In this update the PMEM driver, on x86, gains the ability to assert
    that writes to persistent memory have been flushed all the way
    through the caches and buffers in the platform to persistent media.
    See memcpy_to_pmem() and wmb_pmem().

  BLK:
    This new driver enables access to persistent memory media through
    "Block Data Windows" as defined by the NFIT.  The primary difference
    of this driver to PMEM is that only a small window of persistent
    memory is mapped into system address space at any given point in
    time.

    Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access
    different portions of the media.  BLK-mode, by definition, does not
    support DAX.

  BTT:
    This is a library, optionally consumed by either PMEM or BLK, that
    converts a byte-accessible namespace into a disk with atomic sector
    update semantics (prevents sector tearing on crash or power loss).

    The sinister aspect of sector tearing is that most applications do
    not know they have a atomic sector dependency.  At least today's
    disk's rarely ever tear sectors and if they do one almost certainly
    gets a CRC error on access.  NVDIMMs will always tear and always
    silently.  Until an application is audited to be robust in the
    presence of sector-tearing the usage of BTT is recommended.

  Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
  Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
  Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
  Wysocki, and Bob Moore"

* tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits)
  arch, x86: pmem api for ensuring durability of persistent memory updates
  libnvdimm: Add sysfs numa_node to NVDIMM devices
  libnvdimm: Set numa_node to NVDIMM devices
  acpi: Add acpi_map_pxm_to_online_node()
  libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only
  pmem: flag pmem block devices as non-rotational
  libnvdimm: enable iostat
  pmem: make_request cleanups
  libnvdimm, pmem: fix up max_hw_sectors
  libnvdimm, blk: add support for blk integrity
  libnvdimm, btt: add support for blk integrity
  fs/block_dev.c: skip rw_page if bdev has integrity
  libnvdimm: Non-Volatile Devices
  tools/testing/nvdimm: libnvdimm unit test infrastructure
  libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory
  nd_btt: atomic sector updates
  libnvdimm: infrastructure for btt devices
  libnvdimm: write blk label set
  libnvdimm: write pmem label set
  libnvdimm: blk labels and namespace instantiation
  ...
2015-06-29 10:34:42 -07:00

1157 lines
29 KiB
C

/*
* 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/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.h>
#include <asm/proto.h>
#include <asm/setup.h>
/*
* The e820 map is the map that gets modified e.g. with command line parameters
* and that is also registered with modifications in the kernel resource tree
* with the iomem_resource as parent.
*
* The e820_saved is directly saved after the BIOS-provided memory map is
* copied. It doesn't get modified afterwards. It's registered for the
* /sys/firmware/memmap interface.
*
* That memory map is not modified and is used as base for kexec. The kexec'd
* kernel should get the same memory map as the firmware provides. Then the
* user can e.g. boot the original kernel with mem=1G while still booting the
* next kernel with full memory.
*/
struct e820map e820;
struct e820map e820_saved;
/* 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.
*/
static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
int type)
{
int x = e820x->nr_map;
if (x >= ARRAY_SIZE(e820x->map)) {
printk(KERN_ERR "e820: too many entries; ignoring [mem %#010llx-%#010llx]\n",
(unsigned long long) start,
(unsigned long long) (start + size - 1));
return;
}
e820x->map[x].addr = start;
e820x->map[x].size = size;
e820x->map[x].type = type;
e820x->nr_map++;
}
void __init e820_add_region(u64 start, u64 size, int type)
{
__e820_add_region(&e820, start, size, type);
}
static void __init e820_print_type(u32 type)
{
switch (type) {
case E820_RAM:
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:
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.nr_map; i++) {
printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
(unsigned long long) e820.map[i].addr,
(unsigned long long)
(e820.map[i].addr + e820.map[i].size - 1));
e820_print_type(e820.map[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
* 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). 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_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_
*/
struct change_member {
struct e820entry *pbios; /* pointer to original bios entry */
unsigned long long addr; /* address for this change point */
};
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 unequal, 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_map(struct e820entry *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 e820entry *overlap_list[E820_X_MAX] __initdata;
static struct e820entry 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 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) */
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 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 || 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 original location */
memcpy(biosmap, new_bios, new_nr * sizeof(struct e820entry));
*pnr_map = new_nr;
return 0;
}
static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
{
while (nr_map) {
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;
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_map(struct e820entry *biosmap, int nr_map)
{
/* Only one memory region (or negative)? Ignore it */
if (nr_map < 2)
return -1;
return __append_e820_map(biosmap, nr_map);
}
static u64 __init __e820_update_range(struct e820map *e820x, 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] ",
(unsigned long long) start, (unsigned long long) (end - 1));
e820_print_type(old_type);
printk(KERN_CONT " ==> ");
e820_print_type(new_type);
printk(KERN_CONT "\n");
for (i = 0; i < e820x->nr_map; i++) {
struct e820entry *ei = &e820x->map[i];
u64 final_start, final_end;
u64 ei_end;
if (ei->type != old_type)
continue;
ei_end = ei->addr + ei->size;
/* totally covered by new range? */
if (ei->addr >= start && ei_end <= end) {
ei->type = new_type;
real_updated_size += ei->size;
continue;
}
/* new range is totally covered? */
if (ei->addr < start && ei_end > end) {
__e820_add_region(e820x, start, size, new_type);
__e820_add_region(e820x, 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(e820x, 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
* size at 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, start, size, old_type, new_type);
}
static u64 __init e820_update_range_saved(u64 start, u64 size,
unsigned old_type, unsigned new_type)
{
return __e820_update_range(&e820_saved, start, size, old_type,
new_type);
}
/* make e820 not cover the range */
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] ",
(unsigned long long) start, (unsigned long long) (end - 1));
if (checktype)
e820_print_type(old_type);
printk(KERN_CONT "\n");
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
u64 final_start, final_end;
u64 ei_end;
if (checktype && ei->type != old_type)
continue;
ei_end = ei->addr + ei->size;
/* totally covered? */
if (ei->addr >= start && ei_end <= end) {
real_removed_size += ei->size;
memset(ei, 0, sizeof(struct e820entry));
continue;
}
/* new range is totally 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
* size at 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_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map))
return;
printk(KERN_INFO "e820: modified physical RAM map:\n");
e820_print_map("modified");
}
static void __init update_e820_saved(void)
{
sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map),
&e820_saved.nr_map);
}
#define MAX_GAP_END 0x100000000ull
/*
* Search for a gap in the e820 memory space from start_addr to end_addr.
*/
__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
unsigned long start_addr, unsigned long long end_addr)
{
unsigned long long last;
int i = e820.nr_map;
int found = 0;
last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
while (--i >= 0) {
unsigned long long start = e820.map[i].addr;
unsigned long long end = start + e820.map[i].size;
if (end < start_addr)
continue;
/*
* 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 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;
int found;
gapstart = 0x10000000;
gapsize = 0x400000;
found = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
#ifdef CONFIG_X86_64
if (!found) {
gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
printk(KERN_ERR
"e820: cannot find a gap in the 32bit address range\n"
"e820: PCI devices with unassigned 32bit BARs may break!\n");
}
#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);
}
/**
* Because of the size limitation of struct boot_params, only first
* 128 E820 memory entries are passed to kernel via
* boot_params.e820_map, others are passed via SETUP_E820_EXT node of
* linked list of struct setup_data, which is parsed here.
*/
void __init parse_e820_ext(u64 phys_addr, u32 data_len)
{
int entries;
struct e820entry *extmap;
struct setup_data *sdata;
sdata = early_memremap(phys_addr, data_len);
entries = sdata->len / sizeof(struct e820entry);
extmap = (struct e820entry *)(sdata->data);
__append_e820_map(extmap, entries);
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
early_memunmap(sdata, data_len);
printk(KERN_INFO "e820: extended physical RAM map:\n");
e820_print_map("extended");
}
#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.
*/
void __init e820_mark_nosave_regions(unsigned long limit_pfn)
{
int i;
unsigned long pfn = 0;
for (i = 0; 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 && ei->type != E820_RESERVED_KERN)
register_nosave_region(PFN_UP(ei->addr), pfn);
if (pfn >= limit_pfn)
break;
}
}
#endif
#ifdef CONFIG_ACPI
/**
* Mark ACPI NVS memory region, so that we can save/restore it during
* hibernation and the subsequent resume.
*/
static int __init e820_mark_nvs_memory(void)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[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_saved
*/
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_saved(addr, size, E820_RAM, E820_RESERVED);
printk(KERN_INFO "e820: update e820_saved for early_reserve_e820\n");
update_e820_saved();
}
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)
{
int i;
unsigned long last_pfn = 0;
unsigned long max_arch_pfn = MAX_ARCH_PFN;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
unsigned long start_pfn;
unsigned long end_pfn;
/*
* Persistent memory is accounted as ram for purposes of
* establishing max_pfn and mem_map.
*/
if (ei->type != E820_RAM && ei->type != E820_PRAM)
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);
}
unsigned long __init e820_end_of_low_ram_pfn(void)
{
return e820_end_pfn(1UL << (32-PAGE_SHIFT));
}
static void early_panic(char *msg)
{
early_printk(msg);
panic(msg);
}
static int userdef __initdata;
/* "mem=nopentium" disables the 4MB page tables. */
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 of memory when handling "mem={invalid}" param */
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 mem size before original memory map is
* reset.
*/
saved_max_pfn = e820_end_of_ram_pfn();
#endif
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);
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_map(e820.map, ARRAY_SIZE(e820.map),
&e820.nr_map) < 0)
early_panic("Invalid user supplied memory map");
printk(KERN_INFO "e820: user-defined physical RAM map:\n");
e820_print_map("user");
}
}
static inline const char *e820_type_to_string(int e820_type)
{
switch (e820_type) {
case E820_RESERVED_KERN:
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 bool 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.nr_map);
e820_res = res;
for (i = 0; i < e820.nr_map; i++) {
end = e820.map[i].addr + e820.map[i].size - 1;
if (end != (resource_size_t)end) {
res++;
continue;
}
res->name = e820_type_to_string(e820.map[i].type);
res->start = e820.map[i].addr;
res->end = end;
res->flags = IORESOURCE_MEM;
/*
* 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.map[i].type, res)) {
res->flags |= IORESOURCE_BUSY;
insert_resource(&iomem_resource, res);
}
res++;
}
for (i = 0; i < e820_saved.nr_map; i++) {
struct e820entry *entry = &e820_saved.map[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 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.nr_map; 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.nr_map; i++) {
struct e820entry *entry = &e820.map[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");
}
}
char *__init default_machine_specific_memory_setup(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_map(boot_params.e820_map,
ARRAY_SIZE(boot_params.e820_map),
&new_nr);
boot_params.e820_entries = new_nr;
if (append_e820_map(boot_params.e820_map, boot_params.e820_entries)
< 0) {
u64 mem_size;
/* compare results from other methods and take the greater */
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.nr_map = 0;
e820_add_region(0, LOWMEMSIZE(), E820_RAM);
e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
}
/* In case someone cares... */
return who;
}
void __init setup_memory_map(void)
{
char *who;
who = x86_init.resources.memory_setup();
memcpy(&e820_saved, &e820, sizeof(struct e820map));
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.nr_map; i++) {
struct e820entry *ei = &e820.map[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
}