mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 09:02:00 +00:00
1b72691ce3
This recent patch
commit c3965bd151
Author: Paul Jackson <pj@sgi.com>
Date: Wed May 14 08:15:34 2008 -0700
x86 boot: proper use of ARRAY_SIZE instead of repeated E820MAX constant
caused these new warnings during a normal build:
In file included from linux-2.6/arch/x86/boot/memory.c:17:
linux-2.6/include/linux/log2.h: In function '__ilog2_u32':
linux-2.6/include/linux/log2.h:34: warning: implicit declaration of function 'fls'
linux-2.6/include/linux/log2.h: In function '__ilog2_u64':
linux-2.6/include/linux/log2.h:42: warning: implicit declaration of function 'fls64'
linux-2.6/include/linux/log2.h: In function '__roundup_pow_of_two ':
linux-2.6/include/linux/log2.h:63: warning: implicit declaration of function 'fls_long'
I tried to fix them in log2.h, but it's difficult because the real mode
environment is completely different from a normal kernel environment. Instead
define an own ARRAY_SIZE macro in boot.h, similar to the other private
macros there.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
120 lines
2.5 KiB
C
120 lines
2.5 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
*
|
|
* This file is part of the Linux kernel, and is made available under
|
|
* the terms of the GNU General Public License version 2.
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Memory detection code
|
|
*/
|
|
|
|
#include "boot.h"
|
|
|
|
#define SMAP 0x534d4150 /* ASCII "SMAP" */
|
|
|
|
static int detect_memory_e820(void)
|
|
{
|
|
int count = 0;
|
|
u32 next = 0;
|
|
u32 size, id;
|
|
u8 err;
|
|
struct e820entry *desc = boot_params.e820_map;
|
|
|
|
do {
|
|
size = sizeof(struct e820entry);
|
|
|
|
/* Important: %edx is clobbered by some BIOSes,
|
|
so it must be either used for the error output
|
|
or explicitly marked clobbered. */
|
|
asm("int $0x15; setc %0"
|
|
: "=d" (err), "+b" (next), "=a" (id), "+c" (size),
|
|
"=m" (*desc)
|
|
: "D" (desc), "d" (SMAP), "a" (0xe820));
|
|
|
|
/* BIOSes which terminate the chain with CF = 1 as opposed
|
|
to %ebx = 0 don't always report the SMAP signature on
|
|
the final, failing, probe. */
|
|
if (err)
|
|
break;
|
|
|
|
/* Some BIOSes stop returning SMAP in the middle of
|
|
the search loop. We don't know exactly how the BIOS
|
|
screwed up the map at that point, we might have a
|
|
partial map, the full map, or complete garbage, so
|
|
just return failure. */
|
|
if (id != SMAP) {
|
|
count = 0;
|
|
break;
|
|
}
|
|
|
|
count++;
|
|
desc++;
|
|
} while (next && count < ARRAY_SIZE(boot_params.e820_map));
|
|
|
|
return boot_params.e820_entries = count;
|
|
}
|
|
|
|
static int detect_memory_e801(void)
|
|
{
|
|
u16 ax, bx, cx, dx;
|
|
u8 err;
|
|
|
|
bx = cx = dx = 0;
|
|
ax = 0xe801;
|
|
asm("stc; int $0x15; setc %0"
|
|
: "=m" (err), "+a" (ax), "+b" (bx), "+c" (cx), "+d" (dx));
|
|
|
|
if (err)
|
|
return -1;
|
|
|
|
/* Do we really need to do this? */
|
|
if (cx || dx) {
|
|
ax = cx;
|
|
bx = dx;
|
|
}
|
|
|
|
if (ax > 15*1024)
|
|
return -1; /* Bogus! */
|
|
|
|
/* This ignores memory above 16MB if we have a memory hole
|
|
there. If someone actually finds a machine with a memory
|
|
hole at 16MB and no support for 0E820h they should probably
|
|
generate a fake e820 map. */
|
|
boot_params.alt_mem_k = (ax == 15*1024) ? (dx << 6)+ax : ax;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int detect_memory_88(void)
|
|
{
|
|
u16 ax;
|
|
u8 err;
|
|
|
|
ax = 0x8800;
|
|
asm("stc; int $0x15; setc %0" : "=bcdm" (err), "+a" (ax));
|
|
|
|
boot_params.screen_info.ext_mem_k = ax;
|
|
|
|
return -err;
|
|
}
|
|
|
|
int detect_memory(void)
|
|
{
|
|
int err = -1;
|
|
|
|
if (detect_memory_e820() > 0)
|
|
err = 0;
|
|
|
|
if (!detect_memory_e801())
|
|
err = 0;
|
|
|
|
if (!detect_memory_88())
|
|
err = 0;
|
|
|
|
return err;
|
|
}
|