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 #include <asm/pgtable.h> 20 #include <asm/cacheflush.h> 21 22 void __init check_bugs(void) 23 { 24 identify_boot_cpu(); 25 26 if (!IS_ENABLED(CONFIG_SMP)) { 27 pr_info("CPU: "); 28 print_cpu_info(&boot_cpu_data); 29 } 30 31 #ifdef CONFIG_X86_32 32 /* 33 * Check whether we are able to run this kernel safely on SMP. 34 * 35 * - i386 is no longer supported. 36 * - In order to run on anything without a TSC, we need to be 37 * compiled for a i486. 38 */ 39 if (boot_cpu_data.x86 < 4) 40 panic("Kernel requires i486+ for 'invlpg' and other features"); 41 42 init_utsname()->machine[1] = 43 '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); 44 alternative_instructions(); 45 46 fpu__init_check_bugs(); 47 #else /* CONFIG_X86_64 */ 48 alternative_instructions(); 49 50 /* 51 * Make sure the first 2MB area is not mapped by huge pages 52 * There are typically fixed size MTRRs in there and overlapping 53 * MTRRs into large pages causes slow downs. 54 * 55 * Right now we don't do that with gbpages because there seems 56 * very little benefit for that case. 57 */ 58 if (!direct_gbpages) 59 set_memory_4k((unsigned long)__va(0), 1); 60 #endif 61 } 62