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Diffstat (limited to 'arch/x86/boot/mca.c')
-rw-r--r--arch/x86/boot/mca.c27
1 files changed, 12 insertions, 15 deletions
diff --git a/arch/x86/boot/mca.c b/arch/x86/boot/mca.c
index 911eaae5d696..a95a531148ef 100644
--- a/arch/x86/boot/mca.c
+++ b/arch/x86/boot/mca.c
@@ -2,6 +2,7 @@
2 * 2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds 3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved 4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 * Copyright 2009 Intel Corporation; author H. Peter Anvin
5 * 6 *
6 * This file is part of the Linux kernel, and is made available under 7 * This file is part of the Linux kernel, and is made available under
7 * the terms of the GNU General Public License version 2. 8 * the terms of the GNU General Public License version 2.
@@ -16,26 +17,22 @@
16 17
17int query_mca(void) 18int query_mca(void)
18{ 19{
19 u8 err; 20 struct biosregs ireg, oreg;
20 u16 es, bx, len; 21 u16 len;
21 22
22 asm("pushw %%es ; " 23 initregs(&ireg);
23 "int $0x15 ; " 24 ireg.ah = 0xc0;
24 "setc %0 ; " 25 intcall(0x15, &ireg, &oreg);
25 "movw %%es, %1 ; " 26
26 "popw %%es" 27 if (oreg.eflags & X86_EFLAGS_CF)
27 : "=acd" (err), "=acdSD" (es), "=b" (bx)
28 : "a" (0xc000));
29
30 if (err)
31 return -1; /* No MCA present */ 28 return -1; /* No MCA present */
32 29
33 set_fs(es); 30 set_fs(oreg.es);
34 len = rdfs16(bx); 31 len = rdfs16(oreg.bx);
35 32
36 if (len > sizeof(boot_params.sys_desc_table)) 33 if (len > sizeof(boot_params.sys_desc_table))
37 len = sizeof(boot_params.sys_desc_table); 34 len = sizeof(boot_params.sys_desc_table);
38 35
39 copy_from_fs(&boot_params.sys_desc_table, bx, len); 36 copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len);
40 return 0; 37 return 0;
41} 38}