Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * verify_cpu.S - Code for cpu long mode and SSE verification. This |
| 4 | * code has been borrowed from boot/setup.S and was introduced by |
| 5 | * Andi Kleen. |
| 6 | * |
| 7 | * Copyright (c) 2007 Andi Kleen (ak@suse.de) |
| 8 | * Copyright (c) 2007 Eric Biederman (ebiederm@xmission.com) |
| 9 | * Copyright (c) 2007 Vivek Goyal (vgoyal@in.ibm.com) |
| 10 | * |
| 11 | * This source code is licensed under the GNU General Public License, |
| 12 | * Version 2. See the file COPYING for more details. |
| 13 | * |
| 14 | * This is a common code for verification whether CPU supports |
| 15 | * long mode and SSE or not. It is not called directly instead this |
| 16 | * file is included at various places and compiled in that context. |
| 17 | * Following are the current usage. |
| 18 | * |
| 19 | * This file is included by both 16bit and 32bit code. |
| 20 | * |
| 21 | * arch/x86_64/boot/setup.S : Boot cpu verification (16bit) |
| 22 | * arch/x86_64/boot/compressed/head.S: Boot cpu verification (32bit) |
| 23 | * arch/x86_64/kernel/trampoline.S: secondary processor verfication (16bit) |
| 24 | * arch/x86_64/kernel/acpi/wakeup.S:Verfication at resume (16bit) |
| 25 | * |
| 26 | * verify_cpu, returns the status of cpu check in register %eax. |
| 27 | * 0: Success 1: Failure |
| 28 | * |
| 29 | * The caller needs to check for the error code and take the action |
| 30 | * appropriately. Either display a message or halt. |
| 31 | */ |
| 32 | |
Andi Kleen | 72b1b1d | 2007-05-02 19:27:20 +0200 | [diff] [blame] | 33 | #include <asm/cpufeature.h> |
Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 34 | |
Andi Kleen | 72b1b1d | 2007-05-02 19:27:20 +0200 | [diff] [blame] | 35 | verify_cpu: |
Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 36 | pushfl # Save caller passed flags |
| 37 | pushl $0 # Kill any dangerous flags |
| 38 | popfl |
| 39 | |
Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 40 | pushfl # standard way to check for cpuid |
| 41 | popl %eax |
| 42 | movl %eax,%ebx |
| 43 | xorl $0x200000,%eax |
| 44 | pushl %eax |
| 45 | popfl |
| 46 | pushfl |
| 47 | popl %eax |
| 48 | cmpl %eax,%ebx |
| 49 | jz verify_cpu_no_longmode # cpu has no cpuid |
| 50 | |
| 51 | movl $0x0,%eax # See if cpuid 1 is implemented |
| 52 | cpuid |
| 53 | cmpl $0x1,%eax |
| 54 | jb verify_cpu_no_longmode # no cpuid 1 |
| 55 | |
| 56 | xor %di,%di |
| 57 | cmpl $0x68747541,%ebx # AuthenticAMD |
| 58 | jnz verify_cpu_noamd |
| 59 | cmpl $0x69746e65,%edx |
| 60 | jnz verify_cpu_noamd |
| 61 | cmpl $0x444d4163,%ecx |
| 62 | jnz verify_cpu_noamd |
| 63 | mov $1,%di # cpu is from AMD |
| 64 | |
| 65 | verify_cpu_noamd: |
| 66 | movl $0x1,%eax # Does the cpu have what it takes |
| 67 | cpuid |
H. Peter Anvin | ec48153 | 2007-07-11 12:18:29 -0700 | [diff] [blame] | 68 | andl $REQUIRED_MASK0,%edx |
| 69 | xorl $REQUIRED_MASK0,%edx |
Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 70 | jnz verify_cpu_no_longmode |
| 71 | |
| 72 | movl $0x80000000,%eax # See if extended cpuid is implemented |
| 73 | cpuid |
| 74 | cmpl $0x80000001,%eax |
| 75 | jb verify_cpu_no_longmode # no extended cpuid |
| 76 | |
| 77 | movl $0x80000001,%eax # Does the cpu have what it takes |
| 78 | cpuid |
H. Peter Anvin | ec48153 | 2007-07-11 12:18:29 -0700 | [diff] [blame] | 79 | andl $REQUIRED_MASK1,%edx |
| 80 | xorl $REQUIRED_MASK1,%edx |
Vivek Goyal | a4831e0 | 2007-05-02 19:27:08 +0200 | [diff] [blame] | 81 | jnz verify_cpu_no_longmode |
| 82 | |
| 83 | verify_cpu_sse_test: |
| 84 | movl $1,%eax |
| 85 | cpuid |
| 86 | andl $SSE_MASK,%edx |
| 87 | cmpl $SSE_MASK,%edx |
| 88 | je verify_cpu_sse_ok |
| 89 | test %di,%di |
| 90 | jz verify_cpu_no_longmode # only try to force SSE on AMD |
| 91 | movl $0xc0010015,%ecx # HWCR |
| 92 | rdmsr |
| 93 | btr $15,%eax # enable SSE |
| 94 | wrmsr |
| 95 | xor %di,%di # don't loop |
| 96 | jmp verify_cpu_sse_test # try again |
| 97 | |
| 98 | verify_cpu_no_longmode: |
| 99 | popfl # Restore caller passed flags |
| 100 | movl $1,%eax |
| 101 | ret |
| 102 | verify_cpu_sse_ok: |
| 103 | popfl # Restore caller passed flags |
| 104 | xorl %eax, %eax |
| 105 | ret |