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- /*
- * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- *
- * You can also choose to distribute this program under the terms of
- * the Unmodified Binary Distribution Licence (as given in the file
- * COPYING.UBDL), provided that you have satisfied its requirements.
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- #include <string.h>
- #include <errno.h>
- #include <ipxe/cpuid.h>
-
- /** @file
- *
- * x86 CPU feature detection
- *
- */
-
- /** Colour for debug messages */
- #define colour 0x861d
-
- /**
- * Check whether or not CPUID instruction is supported
- *
- * @ret rc Return status code
- */
- static int cpuid_instruction_supported ( void ) {
- unsigned long original;
- unsigned long inverted;
-
- /* Check for instruction existence via flag modifiability */
- __asm__ ( "pushf\n\t"
- "pushf\n\t"
- "pop %0\n\t"
- "mov %0,%1\n\t"
- "xor %2,%1\n\t"
- "push %1\n\t"
- "popf\n\t"
- "pushf\n\t"
- "pop %1\n\t"
- "popf\n\t"
- : "=&r" ( original ), "=&r" ( inverted )
- : "ir" ( CPUID_FLAG ) );
- if ( ! ( ( original ^ inverted ) & CPUID_FLAG ) ) {
- DBGC ( colour, "CPUID instruction is not supported\n" );
- return -ENOTSUP;
- }
-
- return 0;
- }
-
- /**
- * Check whether or not CPUID function is supported
- *
- * @v function CPUID function
- * @ret rc Return status code
- */
- int cpuid_supported ( uint32_t function ) {
- uint32_t max_function;
- uint32_t discard_b;
- uint32_t discard_c;
- uint32_t discard_d;
- int rc;
-
- /* Check that CPUID instruction is available */
- if ( ( rc = cpuid_instruction_supported() ) != 0 )
- return rc;
-
- /* Find highest supported function number within this family */
- cpuid ( ( function & CPUID_EXTENDED ), 0, &max_function, &discard_b,
- &discard_c, &discard_d );
-
- /* Fail if maximum function number is meaningless (e.g. if we
- * are attempting to call an extended function on a CPU which
- * does not support them).
- */
- if ( ( max_function & CPUID_AMD_CHECK_MASK ) !=
- ( function & CPUID_AMD_CHECK_MASK ) ) {
- DBGC ( colour, "CPUID invalid maximum function %#08x\n",
- max_function );
- return -EINVAL;
- }
-
- /* Fail if this function is not supported */
- if ( function > max_function ) {
- DBGC ( colour, "CPUID function %#08x not supported\n",
- function );
- return -ENOTTY;
- }
-
- return 0;
- }
-
- /**
- * Get Intel-defined x86 CPU features
- *
- * @v features x86 CPU features to fill in
- */
- static void x86_intel_features ( struct x86_features *features ) {
- uint32_t discard_a;
- uint32_t discard_b;
- int rc;
-
- /* Check that features are available via CPUID */
- if ( ( rc = cpuid_supported ( CPUID_FEATURES ) ) != 0 ) {
- DBGC ( features, "CPUID has no Intel-defined features\n" );
- return;
- }
-
- /* Get features */
- cpuid ( CPUID_FEATURES, 0, &discard_a, &discard_b,
- &features->intel.ecx, &features->intel.edx );
- DBGC ( features, "CPUID Intel features: %%ecx=%08x, %%edx=%08x\n",
- features->intel.ecx, features->intel.edx );
-
- }
-
- /**
- * Get AMD-defined x86 CPU features
- *
- * @v features x86 CPU features to fill in
- */
- static void x86_amd_features ( struct x86_features *features ) {
- uint32_t discard_a;
- uint32_t discard_b;
- int rc;
-
- /* Check that features are available via CPUID */
- if ( ( rc = cpuid_supported ( CPUID_AMD_FEATURES ) ) != 0 ) {
- DBGC ( features, "CPUID has no AMD-defined features\n" );
- return;
- }
-
- /* Get features */
- cpuid ( CPUID_AMD_FEATURES, 0, &discard_a, &discard_b,
- &features->amd.ecx, &features->amd.edx );
- DBGC ( features, "CPUID AMD features: %%ecx=%08x, %%edx=%08x\n",
- features->amd.ecx, features->amd.edx );
- }
-
- /**
- * Get x86 CPU features
- *
- * @v features x86 CPU features to fill in
- */
- void x86_features ( struct x86_features *features ) {
-
- /* Clear all features */
- memset ( features, 0, sizeof ( *features ) );
-
- /* Get Intel-defined features */
- x86_intel_features ( features );
-
- /* Get AMD-defined features */
- x86_amd_features ( features );
- }
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