projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| a4831e08 VG |
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 | ||
| 33 | verify_cpu: | |
| 34 | ||
| 35 | pushfl # Save caller passed flags | |
| 36 | pushl $0 # Kill any dangerous flags | |
| 37 | popfl | |
| 38 | ||
| 39 | /* minimum CPUID flags for x86-64 */ | |
| 40 | /* see http://www.x86-64.org/lists/discuss/msg02971.html */ | |
| 41 | #define SSE_MASK ((1<<25)|(1<<26)) | |
| 42 | #define REQUIRED_MASK1 ((1<<0)|(1<<3)|(1<<4)|(1<<5)|(1<<6)|(1<<8)|\ | |
| 43 | (1<<13)|(1<<15)|(1<<24)) | |
| 44 | #define REQUIRED_MASK2 (1<<29) | |
| 45 | pushfl # standard way to check for cpuid | |
| 46 | popl %eax | |
| 47 | movl %eax,%ebx | |
| 48 | xorl $0x200000,%eax | |
| 49 | pushl %eax | |
| 50 | popfl | |
| 51 | pushfl | |
| 52 | popl %eax | |
| 53 | cmpl %eax,%ebx | |
| 54 | jz verify_cpu_no_longmode # cpu has no cpuid | |
| 55 | ||
| 56 | movl $0x0,%eax # See if cpuid 1 is implemented | |
| 57 | cpuid | |
| 58 | cmpl $0x1,%eax | |
| 59 | jb verify_cpu_no_longmode # no cpuid 1 | |
| 60 | ||
| 61 | xor %di,%di | |
| 62 | cmpl $0x68747541,%ebx # AuthenticAMD | |
| 63 | jnz verify_cpu_noamd | |
| 64 | cmpl $0x69746e65,%edx | |
| 65 | jnz verify_cpu_noamd | |
| 66 | cmpl $0x444d4163,%ecx | |
| 67 | jnz verify_cpu_noamd | |
| 68 | mov $1,%di # cpu is from AMD | |
| 69 | ||
| 70 | verify_cpu_noamd: | |
| 71 | movl $0x1,%eax # Does the cpu have what it takes | |
| 72 | cpuid | |
| 73 | andl $REQUIRED_MASK1,%edx | |
| 74 | xorl $REQUIRED_MASK1,%edx | |
| 75 | jnz verify_cpu_no_longmode | |
| 76 | ||
| 77 | movl $0x80000000,%eax # See if extended cpuid is implemented | |
| 78 | cpuid | |
| 79 | cmpl $0x80000001,%eax | |
| 80 | jb verify_cpu_no_longmode # no extended cpuid | |
| 81 | ||
| 82 | movl $0x80000001,%eax # Does the cpu have what it takes | |
| 83 | cpuid | |
| 84 | andl $REQUIRED_MASK2,%edx | |
| 85 | xorl $REQUIRED_MASK2,%edx | |
| 86 | jnz verify_cpu_no_longmode | |
| 87 | ||
| 88 | verify_cpu_sse_test: | |
| 89 | movl $1,%eax | |
| 90 | cpuid | |
| 91 | andl $SSE_MASK,%edx | |
| 92 | cmpl $SSE_MASK,%edx | |
| 93 | je verify_cpu_sse_ok | |
| 94 | test %di,%di | |
| 95 | jz verify_cpu_no_longmode # only try to force SSE on AMD | |
| 96 | movl $0xc0010015,%ecx # HWCR | |
| 97 | rdmsr | |
| 98 | btr $15,%eax # enable SSE | |
| 99 | wrmsr | |
| 100 | xor %di,%di # don't loop | |
| 101 | jmp verify_cpu_sse_test # try again | |
| 102 | ||
| 103 | verify_cpu_no_longmode: | |
| 104 | popfl # Restore caller passed flags | |
| 105 | movl $1,%eax | |
| 106 | ret | |
| 107 | verify_cpu_sse_ok: | |
| 108 | popfl # Restore caller passed flags | |
| 109 | xorl %eax, %eax | |
| 110 | ret |