/* * Copyright (C) 1994 Linus Torvalds * * Cyrix stuff, June 1998 by: * - Rafael R. Reilova (moved everything from head.S), * * - Channing Corn (tests & fixes), * - Andrew D. Balsa (code cleanup). */ #include #include #include #include #include #include #include #include #include #include #include void __init check_bugs(void) { #ifdef CONFIG_X86_32 /* * Regardless of whether PCID is enumerated, the SDM says * that it can't be enabled in 32-bit mode. */ setup_clear_cpu_cap(X86_FEATURE_PCID); #endif identify_boot_cpu(); if (!IS_ENABLED(CONFIG_SMP)) { pr_info("CPU: "); print_cpu_info(&boot_cpu_data); } #ifdef CONFIG_X86_32 /* * Check whether we are able to run this kernel safely on SMP. * * - i386 is no longer supported. * - In order to run on anything without a TSC, we need to be * compiled for a i486. */ if (boot_cpu_data.x86 < 4) panic("Kernel requires i486+ for 'invlpg' and other features"); init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); alternative_instructions(); fpu__init_check_bugs(); #else /* CONFIG_X86_64 */ alternative_instructions(); /* * Make sure the first 2MB area is not mapped by huge pages * There are typically fixed size MTRRs in there and overlapping * MTRRs into large pages causes slow downs. * * Right now we don't do that with gbpages because there seems * very little benefit for that case. */ if (!direct_gbpages) set_memory_4k((unsigned long)__va(0), 1); #endif }