1/*
 2 *  Copyright (C) 1994  Linus Torvalds
 3 *
 4 *  Cyrix stuff, June 1998 by:
 5 *	- Rafael R. Reilova (moved everything from head.S),
 6 *        <rreilova@ececs.uc.edu>
 7 *	- Channing Corn (tests & fixes),
 8 *	- Andrew D. Balsa (code cleanup).
 9 */
10#include <linux/init.h>
11#include <linux/utsname.h>
12#include <asm/bugs.h>
13#include <asm/processor.h>
14#include <asm/processor-flags.h>
15#include <asm/fpu/internal.h>
16#include <asm/msr.h>
17#include <asm/paravirt.h>
18#include <asm/alternative.h>
19
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
20void __init check_bugs(void)
21{
22	identify_boot_cpu();
23#ifndef CONFIG_SMP
24	pr_info("CPU: ");
25	print_cpu_info(&boot_cpu_data);
26#endif
27
28	/*
29	 * Check whether we are able to run this kernel safely on SMP.
30	 *
31	 * - i386 is no longer supported.
32	 * - In order to run on anything without a TSC, we need to be
33	 *   compiled for a i486.
34	 */
35	if (boot_cpu_data.x86 < 4)
36		panic("Kernel requires i486+ for 'invlpg' and other features");
37
38	init_utsname()->machine[1] =
39		'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
40	alternative_instructions();
41
42	fpu__init_check_bugs();
 
 
 
 
 
43}

 1/*
 2 *  Copyright (C) 1994  Linus Torvalds
 3 *
 4 *  Cyrix stuff, June 1998 by:
 5 *	- Rafael R. Reilova (moved everything from head.S),
 6 *        <rreilova@ececs.uc.edu>
 7 *	- Channing Corn (tests & fixes),
 8 *	- Andrew D. Balsa (code cleanup).
 9 */
10#include <linux/init.h>
11#include <linux/utsname.h>
12#include <asm/bugs.h>
13#include <asm/processor.h>
14#include <asm/processor-flags.h>
15#include <asm/i387.h>
16#include <asm/msr.h>
17#include <asm/paravirt.h>
18#include <asm/alternative.h>
19
20static double __initdata x = 4195835.0;
21static double __initdata y = 3145727.0;
22
23/*
24 * This used to check for exceptions..
25 * However, it turns out that to support that,
26 * the XMM trap handlers basically had to
27 * be buggy. So let's have a correct XMM trap
28 * handler, and forget about printing out
29 * some status at boot.
30 *
31 * We should really only care about bugs here
32 * anyway. Not features.
33 */
34static void __init check_fpu(void)
35{
36	s32 fdiv_bug;
37
38	kernel_fpu_begin();
39
40	/*
41	 * trap_init() enabled FXSR and company _before_ testing for FP
42	 * problems here.
43	 *
44	 * Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug
45	 */
46	__asm__("fninit\n\t"
47		"fldl %1\n\t"
48		"fdivl %2\n\t"
49		"fmull %2\n\t"
50		"fldl %1\n\t"
51		"fsubp %%st,%%st(1)\n\t"
52		"fistpl %0\n\t"
53		"fwait\n\t"
54		"fninit"
55		: "=m" (*&fdiv_bug)
56		: "m" (*&x), "m" (*&y));
57
58	kernel_fpu_end();
59
60	if (fdiv_bug) {
61		set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV);
62		pr_warn("Hmm, FPU with FDIV bug\n");
63	}
64}
65
66void __init check_bugs(void)
67{
68	identify_boot_cpu();
69#ifndef CONFIG_SMP
70	pr_info("CPU: ");
71	print_cpu_info(&boot_cpu_data);
72#endif
73
74	/*
75	 * Check whether we are able to run this kernel safely on SMP.
76	 *
77	 * - i386 is no longer supported.
78	 * - In order to run on anything without a TSC, we need to be
79	 *   compiled for a i486.
80	 */
81	if (boot_cpu_data.x86 < 4)
82		panic("Kernel requires i486+ for 'invlpg' and other features");
83
84	init_utsname()->machine[1] =
85		'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
86	alternative_instructions();
87
88	/*
89	 * kernel_fpu_begin/end() in check_fpu() relies on the patched
90	 * alternative instructions.
91	 */
92	if (cpu_has_fpu)
93		check_fpu();
94}