Commit 7b80ba55 authored by Ingo Molnar's avatar Ingo Molnar

x86/boot/e820: Clean up and improve comments in asm/e820/types.h

Do some common-sense cleanups:

 - standardize on the kernel coding style consistently

 - tabulate definitions consistently

 - extend and clarify various descriptions

 - fix speling

 - update the header guard name according to the new position

 - etc.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 70a9d818
#ifndef _UAPI_ASM_X86_E820_H
#define _UAPI_ASM_X86_E820_H
#define E820MAP 0x2d0 /* our map */
#define E820MAX 128 /* number of entries in E820MAP */
#ifndef _ASM_E820_TYPES_H
#define _ASM_E820_TYPES_H
/* Our map: */
#define E820MAP 0x2d0
/* The maximum number of entries in E820MAP: */
#define E820MAX 128
/*
* 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
* The legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
* constrained space in the zeropage.
*
* On large systems we can easily have thousands of nodes with RAM,
* which cannot be fit into so few entries - so we have a mechanism
* to extend the e820 table size at build-time, via the E820_X_MAX
* define below.
*
* ( Those extra entries are enumerated via the EFI memory map, not
* via the legacy zeropage mechanism. )
*
* Size our internal memory map tables to have room for these additional
* entries, based on a heuristic calculation: up to three entries per
* NUMA node, plus E820MAX for some extra space.
*
* This allows for bootstrap/firmware quirks such as 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
......@@ -20,12 +32,12 @@
* to allow more than three entries per node or otherwise refine
* this size.
*/
#ifndef __KERNEL__
#define E820_X_MAX E820MAX
# define E820_X_MAX E820MAX
#endif
#define E820NR 0x1e8 /* # entries in E820MAP */
/* Number of entries in E820MAP: */
#define E820NR 0x1e8
#define E820_RAM 1
#define E820_RESERVED 2
......@@ -55,19 +67,30 @@
#ifndef __ASSEMBLY__
#include <linux/types.h>
/*
* A single E820 map entry, describing a memory range of [addr...addr+size-1],
* of 'type' memory type:
*/
struct e820entry {
__u64 addr; /* start of memory segment */
__u64 size; /* size of memory segment */
__u32 type; /* type of memory segment */
__u64 addr;
__u64 size;
__u32 type;
} __attribute__((packed));
/*
* The whole array of E820 entries:
*/
struct e820map {
__u32 nr_map;
struct e820entry map[E820_X_MAX];
};
#define ISA_START_ADDRESS 0xa0000
#define ISA_END_ADDRESS 0x100000
/*
* Various legacy ranges in physical memory:
*/
#define ISA_START_ADDRESS 0x000a0000
#define ISA_END_ADDRESS 0x00100000
#define BIOS_BEGIN 0x000a0000
#define BIOS_END 0x00100000
......@@ -77,5 +100,4 @@ struct e820map {
#endif /* __ASSEMBLY__ */
#endif /* _UAPI_ASM_X86_E820_H */
#endif /* _ASM_E820_TYPES_H */
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