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-rw-r--r--arch/x86/kernel/verify_cpu.S50
1 files changed, 25 insertions, 25 deletions
diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S
index 4cf401f581e7..07efb35ee4bc 100644
--- a/arch/x86/kernel/verify_cpu.S
+++ b/arch/x86/kernel/verify_cpu.S
@@ -48,31 +48,31 @@ verify_cpu:
48 pushfl 48 pushfl
49 popl %eax 49 popl %eax
50 cmpl %eax,%ebx 50 cmpl %eax,%ebx
51 jz verify_cpu_no_longmode # cpu has no cpuid 51 jz .Lverify_cpu_no_longmode # cpu has no cpuid
52#endif 52#endif
53 53
54 movl $0x0,%eax # See if cpuid 1 is implemented 54 movl $0x0,%eax # See if cpuid 1 is implemented
55 cpuid 55 cpuid
56 cmpl $0x1,%eax 56 cmpl $0x1,%eax
57 jb verify_cpu_no_longmode # no cpuid 1 57 jb .Lverify_cpu_no_longmode # no cpuid 1
58 58
59 xor %di,%di 59 xor %di,%di
60 cmpl $0x68747541,%ebx # AuthenticAMD 60 cmpl $0x68747541,%ebx # AuthenticAMD
61 jnz verify_cpu_noamd 61 jnz .Lverify_cpu_noamd
62 cmpl $0x69746e65,%edx 62 cmpl $0x69746e65,%edx
63 jnz verify_cpu_noamd 63 jnz .Lverify_cpu_noamd
64 cmpl $0x444d4163,%ecx 64 cmpl $0x444d4163,%ecx
65 jnz verify_cpu_noamd 65 jnz .Lverify_cpu_noamd
66 mov $1,%di # cpu is from AMD 66 mov $1,%di # cpu is from AMD
67 jmp verify_cpu_check 67 jmp .Lverify_cpu_check
68 68
69verify_cpu_noamd: 69.Lverify_cpu_noamd:
70 cmpl $0x756e6547,%ebx # GenuineIntel? 70 cmpl $0x756e6547,%ebx # GenuineIntel?
71 jnz verify_cpu_check 71 jnz .Lverify_cpu_check
72 cmpl $0x49656e69,%edx 72 cmpl $0x49656e69,%edx
73 jnz verify_cpu_check 73 jnz .Lverify_cpu_check
74 cmpl $0x6c65746e,%ecx 74 cmpl $0x6c65746e,%ecx
75 jnz verify_cpu_check 75 jnz .Lverify_cpu_check
76 76
77 # only call IA32_MISC_ENABLE when: 77 # only call IA32_MISC_ENABLE when:
78 # family > 6 || (family == 6 && model >= 0xd) 78 # family > 6 || (family == 6 && model >= 0xd)
@@ -83,59 +83,59 @@ verify_cpu_noamd:
83 andl $0x0ff00f00, %eax # mask family and extended family 83 andl $0x0ff00f00, %eax # mask family and extended family
84 shrl $8, %eax 84 shrl $8, %eax
85 cmpl $6, %eax 85 cmpl $6, %eax
86 ja verify_cpu_clear_xd # family > 6, ok 86 ja .Lverify_cpu_clear_xd # family > 6, ok
87 jb verify_cpu_check # family < 6, skip 87 jb .Lverify_cpu_check # family < 6, skip
88 88
89 andl $0x000f00f0, %ecx # mask model and extended model 89 andl $0x000f00f0, %ecx # mask model and extended model
90 shrl $4, %ecx 90 shrl $4, %ecx
91 cmpl $0xd, %ecx 91 cmpl $0xd, %ecx
92 jb verify_cpu_check # family == 6, model < 0xd, skip 92 jb .Lverify_cpu_check # family == 6, model < 0xd, skip
93 93
94verify_cpu_clear_xd: 94.Lverify_cpu_clear_xd:
95 movl $MSR_IA32_MISC_ENABLE, %ecx 95 movl $MSR_IA32_MISC_ENABLE, %ecx
96 rdmsr 96 rdmsr
97 btrl $2, %edx # clear MSR_IA32_MISC_ENABLE_XD_DISABLE 97 btrl $2, %edx # clear MSR_IA32_MISC_ENABLE_XD_DISABLE
98 jnc verify_cpu_check # only write MSR if bit was changed 98 jnc .Lverify_cpu_check # only write MSR if bit was changed
99 wrmsr 99 wrmsr
100 100
101verify_cpu_check: 101.Lverify_cpu_check:
102 movl $0x1,%eax # Does the cpu have what it takes 102 movl $0x1,%eax # Does the cpu have what it takes
103 cpuid 103 cpuid
104 andl $REQUIRED_MASK0,%edx 104 andl $REQUIRED_MASK0,%edx
105 xorl $REQUIRED_MASK0,%edx 105 xorl $REQUIRED_MASK0,%edx
106 jnz verify_cpu_no_longmode 106 jnz .Lverify_cpu_no_longmode
107 107
108 movl $0x80000000,%eax # See if extended cpuid is implemented 108 movl $0x80000000,%eax # See if extended cpuid is implemented
109 cpuid 109 cpuid
110 cmpl $0x80000001,%eax 110 cmpl $0x80000001,%eax
111 jb verify_cpu_no_longmode # no extended cpuid 111 jb .Lverify_cpu_no_longmode # no extended cpuid
112 112
113 movl $0x80000001,%eax # Does the cpu have what it takes 113 movl $0x80000001,%eax # Does the cpu have what it takes
114 cpuid 114 cpuid
115 andl $REQUIRED_MASK1,%edx 115 andl $REQUIRED_MASK1,%edx
116 xorl $REQUIRED_MASK1,%edx 116 xorl $REQUIRED_MASK1,%edx
117 jnz verify_cpu_no_longmode 117 jnz .Lverify_cpu_no_longmode
118 118
119verify_cpu_sse_test: 119.Lverify_cpu_sse_test:
120 movl $1,%eax 120 movl $1,%eax
121 cpuid 121 cpuid
122 andl $SSE_MASK,%edx 122 andl $SSE_MASK,%edx
123 cmpl $SSE_MASK,%edx 123 cmpl $SSE_MASK,%edx
124 je verify_cpu_sse_ok 124 je .Lverify_cpu_sse_ok
125 test %di,%di 125 test %di,%di
126 jz verify_cpu_no_longmode # only try to force SSE on AMD 126 jz .Lverify_cpu_no_longmode # only try to force SSE on AMD
127 movl $MSR_K7_HWCR,%ecx 127 movl $MSR_K7_HWCR,%ecx
128 rdmsr 128 rdmsr
129 btr $15,%eax # enable SSE 129 btr $15,%eax # enable SSE
130 wrmsr 130 wrmsr
131 xor %di,%di # don't loop 131 xor %di,%di # don't loop
132 jmp verify_cpu_sse_test # try again 132 jmp .Lverify_cpu_sse_test # try again
133 133
134verify_cpu_no_longmode: 134.Lverify_cpu_no_longmode:
135 popf # Restore caller passed flags 135 popf # Restore caller passed flags
136 movl $1,%eax 136 movl $1,%eax
137 ret 137 ret
138verify_cpu_sse_ok: 138.Lverify_cpu_sse_ok:
139 popf # Restore caller passed flags 139 popf # Restore caller passed flags
140 xorl %eax, %eax 140 xorl %eax, %eax
141 ret 141 ret
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-26 17:44:06 -0500