aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--arch/i386/kernel/cpu/Makefile2
-rw-r--r--arch/i386/kernel/cpu/bugs.c191
-rw-r--r--include/asm-i386/alternative.h1
-rw-r--r--include/asm-i386/bugs.h194
4 files changed, 197 insertions, 191 deletions
diff --git a/arch/i386/kernel/cpu/Makefile b/arch/i386/kernel/cpu/Makefile
index 010aecfffbc1..5fb1a7560438 100644
--- a/arch/i386/kernel/cpu/Makefile
+++ b/arch/i386/kernel/cpu/Makefile
@@ -2,7 +2,7 @@
2# Makefile for x86-compatible CPU details and quirks 2# Makefile for x86-compatible CPU details and quirks
3# 3#
4 4
5obj-y := common.o proc.o 5obj-y := common.o proc.o bugs.o
6 6
7obj-y += amd.o 7obj-y += amd.o
8obj-y += cyrix.o 8obj-y += cyrix.o
diff --git a/arch/i386/kernel/cpu/bugs.c b/arch/i386/kernel/cpu/bugs.c
new file mode 100644
index 000000000000..54428a2500f3
--- /dev/null
+++ b/arch/i386/kernel/cpu/bugs.c
@@ -0,0 +1,191 @@
1/*
2 * arch/i386/cpu/bugs.c
3 *
4 * Copyright (C) 1994 Linus Torvalds
5 *
6 * Cyrix stuff, June 1998 by:
7 * - Rafael R. Reilova (moved everything from head.S),
8 * <rreilova@ececs.uc.edu>
9 * - Channing Corn (tests & fixes),
10 * - Andrew D. Balsa (code cleanup).
11 */
12#include <linux/init.h>
13#include <linux/utsname.h>
14#include <asm/processor.h>
15#include <asm/i387.h>
16#include <asm/msr.h>
17#include <asm/paravirt.h>
18#include <asm/alternative.h>
19
20static int __init no_halt(char *s)
21{
22 boot_cpu_data.hlt_works_ok = 0;
23 return 1;
24}
25
26__setup("no-hlt", no_halt);
27
28static int __init mca_pentium(char *s)
29{
30 mca_pentium_flag = 1;
31 return 1;
32}
33
34__setup("mca-pentium", mca_pentium);
35
36static int __init no_387(char *s)
37{
38 boot_cpu_data.hard_math = 0;
39 write_cr0(0xE | read_cr0());
40 return 1;
41}
42
43__setup("no387", no_387);
44
45static double __initdata x = 4195835.0;
46static double __initdata y = 3145727.0;
47
48/*
49 * This used to check for exceptions..
50 * However, it turns out that to support that,
51 * the XMM trap handlers basically had to
52 * be buggy. So let's have a correct XMM trap
53 * handler, and forget about printing out
54 * some status at boot.
55 *
56 * We should really only care about bugs here
57 * anyway. Not features.
58 */
59static void __init check_fpu(void)
60{
61 if (!boot_cpu_data.hard_math) {
62#ifndef CONFIG_MATH_EMULATION
63 printk(KERN_EMERG "No coprocessor found and no math emulation present.\n");
64 printk(KERN_EMERG "Giving up.\n");
65 for (;;) ;
66#endif
67 return;
68 }
69
70/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */
71 /* Test for the divl bug.. */
72 __asm__("fninit\n\t"
73 "fldl %1\n\t"
74 "fdivl %2\n\t"
75 "fmull %2\n\t"
76 "fldl %1\n\t"
77 "fsubp %%st,%%st(1)\n\t"
78 "fistpl %0\n\t"
79 "fwait\n\t"
80 "fninit"
81 : "=m" (*&boot_cpu_data.fdiv_bug)
82 : "m" (*&x), "m" (*&y));
83 if (boot_cpu_data.fdiv_bug)
84 printk("Hmm, FPU with FDIV bug.\n");
85}
86
87static void __init check_hlt(void)
88{
89 if (paravirt_enabled())
90 return;
91
92 printk(KERN_INFO "Checking 'hlt' instruction... ");
93 if (!boot_cpu_data.hlt_works_ok) {
94 printk("disabled\n");
95 return;
96 }
97 halt();
98 halt();
99 halt();
100 halt();
101 printk("OK.\n");
102}
103
104/*
105 * Most 386 processors have a bug where a POPAD can lock the
106 * machine even from user space.
107 */
108
109static void __init check_popad(void)
110{
111#ifndef CONFIG_X86_POPAD_OK
112 int res, inp = (int) &res;
113
114 printk(KERN_INFO "Checking for popad bug... ");
115 __asm__ __volatile__(
116 "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx "
117 : "=&a" (res)
118 : "d" (inp)
119 : "ecx", "edi" );
120 /* If this fails, it means that any user program may lock the CPU hard. Too bad. */
121 if (res != 12345678) printk( "Buggy.\n" );
122 else printk( "OK.\n" );
123#endif
124}
125
126/*
127 * Check whether we are able to run this kernel safely on SMP.
128 *
129 * - In order to run on a i386, we need to be compiled for i386
130 * (for due to lack of "invlpg" and working WP on a i386)
131 * - In order to run on anything without a TSC, we need to be
132 * compiled for a i486.
133 * - In order to support the local APIC on a buggy Pentium machine,
134 * we need to be compiled with CONFIG_X86_GOOD_APIC disabled,
135 * which happens implicitly if compiled for a Pentium or lower
136 * (unless an advanced selection of CPU features is used) as an
137 * otherwise config implies a properly working local APIC without
138 * the need to do extra reads from the APIC.
139*/
140
141static void __init check_config(void)
142{
143/*
144 * We'd better not be a i386 if we're configured to use some
145 * i486+ only features! (WP works in supervisor mode and the
146 * new "invlpg" and "bswap" instructions)
147 */
148#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP)
149 if (boot_cpu_data.x86 == 3)
150 panic("Kernel requires i486+ for 'invlpg' and other features");
151#endif
152
153/*
154 * If we configured ourselves for a TSC, we'd better have one!
155 */
156#ifdef CONFIG_X86_TSC
157 if (!cpu_has_tsc && !tsc_disable)
158 panic("Kernel compiled for Pentium+, requires TSC feature!");
159#endif
160
161/*
162 * If we were told we had a good local APIC, check for buggy Pentia,
163 * i.e. all B steppings and the C2 stepping of P54C when using their
164 * integrated APIC (see 11AP erratum in "Pentium Processor
165 * Specification Update").
166 */
167#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC)
168 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL
169 && cpu_has_apic
170 && boot_cpu_data.x86 == 5
171 && boot_cpu_data.x86_model == 2
172 && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11))
173 panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!");
174#endif
175}
176
177
178void __init check_bugs(void)
179{
180 identify_boot_cpu();
181#ifndef CONFIG_SMP
182 printk("CPU: ");
183 print_cpu_info(&boot_cpu_data);
184#endif
185 check_config();
186 check_fpu();
187 check_hlt();
188 check_popad();
189 init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
190 alternative_instructions();
191}
diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h
index b8fa9557c532..dbc1a29284f3 100644
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -16,6 +16,7 @@ struct alt_instr {
16 u8 pad; 16 u8 pad;
17}; 17};
18 18
19extern void alternative_instructions(void);
19extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); 20extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
20 21
21struct module; 22struct module;
diff --git a/include/asm-i386/bugs.h b/include/asm-i386/bugs.h
index c90c7c499302..df539b390448 100644
--- a/include/asm-i386/bugs.h
+++ b/include/asm-i386/bugs.h
@@ -1,198 +1,12 @@
1/* 1/*
2 * include/asm-i386/bugs.h
3 *
4 * Copyright (C) 1994 Linus Torvalds
5 *
6 * Cyrix stuff, June 1998 by:
7 * - Rafael R. Reilova (moved everything from head.S),
8 * <rreilova@ececs.uc.edu>
9 * - Channing Corn (tests & fixes),
10 * - Andrew D. Balsa (code cleanup).
11 */
12
13/*
14 * This is included by init/main.c to check for architecture-dependent bugs. 2 * This is included by init/main.c to check for architecture-dependent bugs.
15 * 3 *
16 * Needs: 4 * Needs:
17 * void check_bugs(void); 5 * void check_bugs(void);
18 */ 6 */
7#ifndef _ASM_I386_BUG_H
8#define _ASM_I386_BUG_H
19 9
20#include <linux/init.h> 10extern void __init check_bugs(void);
21#include <asm/processor.h>
22#include <asm/i387.h>
23#include <asm/msr.h>
24#include <asm/paravirt.h>
25
26static int __init no_halt(char *s)
27{
28 boot_cpu_data.hlt_works_ok = 0;
29 return 1;
30}
31
32__setup("no-hlt", no_halt);
33
34static int __init mca_pentium(char *s)
35{
36 mca_pentium_flag = 1;
37 return 1;
38}
39
40__setup("mca-pentium", mca_pentium);
41
42static int __init no_387(char *s)
43{
44 boot_cpu_data.hard_math = 0;
45 write_cr0(0xE | read_cr0());
46 return 1;
47}
48
49__setup("no387", no_387);
50
51static double __initdata x = 4195835.0;
52static double __initdata y = 3145727.0;
53
54/*
55 * This used to check for exceptions..
56 * However, it turns out that to support that,
57 * the XMM trap handlers basically had to
58 * be buggy. So let's have a correct XMM trap
59 * handler, and forget about printing out
60 * some status at boot.
61 *
62 * We should really only care about bugs here
63 * anyway. Not features.
64 */
65static void __init check_fpu(void)
66{
67 if (!boot_cpu_data.hard_math) {
68#ifndef CONFIG_MATH_EMULATION
69 printk(KERN_EMERG "No coprocessor found and no math emulation present.\n");
70 printk(KERN_EMERG "Giving up.\n");
71 for (;;) ;
72#endif
73 return;
74 }
75
76/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */
77 /* Test for the divl bug.. */
78 __asm__("fninit\n\t"
79 "fldl %1\n\t"
80 "fdivl %2\n\t"
81 "fmull %2\n\t"
82 "fldl %1\n\t"
83 "fsubp %%st,%%st(1)\n\t"
84 "fistpl %0\n\t"
85 "fwait\n\t"
86 "fninit"
87 : "=m" (*&boot_cpu_data.fdiv_bug)
88 : "m" (*&x), "m" (*&y));
89 if (boot_cpu_data.fdiv_bug)
90 printk("Hmm, FPU with FDIV bug.\n");
91}
92
93static void __init check_hlt(void)
94{
95 if (paravirt_enabled())
96 return;
97
98 printk(KERN_INFO "Checking 'hlt' instruction... ");
99 if (!boot_cpu_data.hlt_works_ok) {
100 printk("disabled\n");
101 return;
102 }
103 halt();
104 halt();
105 halt();
106 halt();
107 printk("OK.\n");
108}
109
110/*
111 * Most 386 processors have a bug where a POPAD can lock the
112 * machine even from user space.
113 */
114
115static void __init check_popad(void)
116{
117#ifndef CONFIG_X86_POPAD_OK
118 int res, inp = (int) &res;
119
120 printk(KERN_INFO "Checking for popad bug... ");
121 __asm__ __volatile__(
122 "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx "
123 : "=&a" (res)
124 : "d" (inp)
125 : "ecx", "edi" );
126 /* If this fails, it means that any user program may lock the CPU hard. Too bad. */
127 if (res != 12345678) printk( "Buggy.\n" );
128 else printk( "OK.\n" );
129#endif
130}
131
132/*
133 * Check whether we are able to run this kernel safely on SMP.
134 *
135 * - In order to run on a i386, we need to be compiled for i386
136 * (for due to lack of "invlpg" and working WP on a i386)
137 * - In order to run on anything without a TSC, we need to be
138 * compiled for a i486.
139 * - In order to support the local APIC on a buggy Pentium machine,
140 * we need to be compiled with CONFIG_X86_GOOD_APIC disabled,
141 * which happens implicitly if compiled for a Pentium or lower
142 * (unless an advanced selection of CPU features is used) as an
143 * otherwise config implies a properly working local APIC without
144 * the need to do extra reads from the APIC.
145*/
146
147static void __init check_config(void)
148{
149/*
150 * We'd better not be a i386 if we're configured to use some
151 * i486+ only features! (WP works in supervisor mode and the
152 * new "invlpg" and "bswap" instructions)
153 */
154#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP)
155 if (boot_cpu_data.x86 == 3)
156 panic("Kernel requires i486+ for 'invlpg' and other features");
157#endif
158
159/*
160 * If we configured ourselves for a TSC, we'd better have one!
161 */
162#ifdef CONFIG_X86_TSC
163 if (!cpu_has_tsc && !tsc_disable)
164 panic("Kernel compiled for Pentium+, requires TSC feature!");
165#endif
166
167/*
168 * If we were told we had a good local APIC, check for buggy Pentia,
169 * i.e. all B steppings and the C2 stepping of P54C when using their
170 * integrated APIC (see 11AP erratum in "Pentium Processor
171 * Specification Update").
172 */
173#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC)
174 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL
175 && cpu_has_apic
176 && boot_cpu_data.x86 == 5
177 && boot_cpu_data.x86_model == 2
178 && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11))
179 panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!");
180#endif
181}
182
183extern void alternative_instructions(void);
184 11
185static void __init check_bugs(void) 12#endif /* _ASM_I386_BUG_H */
186{
187 identify_cpu(&boot_cpu_data);
188#ifndef CONFIG_SMP
189 printk("CPU: ");
190 print_cpu_info(&boot_cpu_data);
191#endif
192 check_config();
193 check_fpu();
194 check_hlt();
195 check_popad();
196 init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
197 alternative_instructions();
198}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-14 07:49:01 -0500