linux/include/asm-x86/e820.h
Paul Jackson c4ba1320b7 x86 boot: allow overlapping early reserve memory ranges
Add support for overlapping early memory reservations.

In general, they still can't overlap, and will panic
with "Overlapping early reservations" if they do overlap.

But if a memory range is reserved with the new call:
    reserve_early_overlap_ok()
rather than with the usual call:
    reserve_early()
then subsequent early reservations are allowed to overlap.

This new reserve_early_overlap_ok() call is only used in one
place so far, which is the "BIOS reserved" reservation for the
the EBDA region, which out of Paranoia reserves more than what
the BIOS might have specified, and which thus might overlap with
another legitimate early memory reservation (such as, perhaps,
the EFI memmap.)

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Cc: "Jack Steiner" <steiner@sgi.com>
Cc: "Mike Travis" <travis@sgi.com>
Cc: "Huang
Cc: Ying" <ying.huang@intel.com>
Cc: "Andi Kleen" <andi@firstfloor.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08 12:51:26 +02:00

128 lines
4.2 KiB
C

#ifndef __ASM_E820_H
#define __ASM_E820_H
#define E820MAP 0x2d0 /* our map */
#define E820MAX 128 /* number of entries in E820MAP */
/*
* Legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
* constrained space in the zeropage. If we have more nodes than
* that, and if we've booted off EFI firmware, then the EFI tables
* passed us from the EFI firmware can list more nodes. Size our
* internal memory map tables to have room for these additional
* nodes, based on up to three entries per node for which the
* kernel was built: MAX_NUMNODES == (1 << CONFIG_NODES_SHIFT),
* plus E820MAX, allowing space for the possible duplicate E820
* entries that might need room in the same arrays, prior to the
* call to sanitize_e820_map() to remove duplicates. The allowance
* of three memory map entries per node is "enough" entries for
* the initial hardware platform motivating this mechanism to make
* use of additional EFI map entries. Future platforms may want
* to allow more than three entries per node or otherwise refine
* this size.
*/
/*
* Odd: 'make headers_check' complains about numa.h if I try
* to collapse the next two #ifdef lines to a single line:
* #if defined(__KERNEL__) && defined(CONFIG_EFI)
*/
#ifdef __KERNEL__
#ifdef CONFIG_EFI
#include <linux/numa.h>
#define E820_X_MAX (E820MAX + 3 * MAX_NUMNODES)
#else /* ! CONFIG_EFI */
#define E820_X_MAX E820MAX
#endif
#else /* ! __KERNEL__ */
#define E820_X_MAX E820MAX
#endif
#define E820NR 0x1e8 /* # entries in E820MAP */
#define E820_RAM 1
#define E820_RESERVED 2
#define E820_ACPI 3
#define E820_NVS 4
#ifndef __ASSEMBLY__
struct e820entry {
__u64 addr; /* start of memory segment */
__u64 size; /* size of memory segment */
__u32 type; /* type of memory segment */
} __attribute__((packed));
struct e820map {
__u32 nr_map;
struct e820entry map[E820_X_MAX];
};
extern struct e820map e820;
extern int e820_any_mapped(u64 start, u64 end, unsigned type);
extern int e820_all_mapped(u64 start, u64 end, unsigned type);
extern void e820_add_region(u64 start, u64 size, int type);
extern void e820_print_map(char *who);
extern int
sanitize_e820_map(struct e820entry *biosmap, int max_nr_map, int *pnr_map);
extern int copy_e820_map(struct e820entry *biosmap, int nr_map);
extern u64 e820_update_range(u64 start, u64 size, unsigned old_type,
unsigned new_type);
extern u64 e820_remove_range(u64 start, u64 size, unsigned old_type,
int checktype);
extern void update_e820(void);
extern void e820_setup_gap(void);
struct setup_data;
extern void parse_e820_ext(struct setup_data *data, unsigned long pa_data);
#if defined(CONFIG_X86_64) || \
(defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
extern void e820_mark_nosave_regions(unsigned long limit_pfn);
#else
static inline void e820_mark_nosave_regions(unsigned long limit_pfn)
{
}
#endif
extern unsigned long end_user_pfn;
extern u64 find_e820_area(u64 start, u64 end, u64 size, u64 align);
extern u64 find_e820_area_size(u64 start, u64 *sizep, u64 align);
extern void reserve_early(u64 start, u64 end, char *name);
extern void reserve_early_overlap_ok(u64 start, u64 end, char *name);
extern void free_early(u64 start, u64 end);
extern void early_res_to_bootmem(u64 start, u64 end);
extern u64 early_reserve_e820(u64 startt, u64 sizet, u64 align);
extern unsigned long e820_end_of_ram(void);
extern int e820_find_active_region(const struct e820entry *ei,
unsigned long start_pfn,
unsigned long last_pfn,
unsigned long *ei_startpfn,
unsigned long *ei_endpfn);
extern void e820_register_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern u64 e820_hole_size(u64 start, u64 end);
extern void finish_e820_parsing(void);
extern void e820_reserve_resources(void);
extern void setup_memory_map(void);
extern char *default_machine_specific_memory_setup(void);
extern char *machine_specific_memory_setup(void);
extern char *memory_setup(void);
#endif /* __ASSEMBLY__ */
#define ISA_START_ADDRESS 0xa0000
#define ISA_END_ADDRESS 0x100000
#define is_ISA_range(s, e) ((s) >= ISA_START_ADDRESS && (e) < ISA_END_ADDRESS)
#define BIOS_BEGIN 0x000a0000
#define BIOS_END 0x00100000
#ifdef __KERNEL__
#include <linux/ioport.h>
#define HIGH_MEMORY (1024*1024)
#endif /* __KERNEL__ */
#endif /* __ASM_E820_H */