diff options
| -rw-r--r-- | src/arch/x86/core/cpuid_settings.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/arch/x86/core/cpuid_settings.c b/src/arch/x86/core/cpuid_settings.c index 0b67ee9..9bc69f4 100644 --- a/src/arch/x86/core/cpuid_settings.c +++ b/src/arch/x86/core/cpuid_settings.c @@ -38,7 +38,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); * * Bit 31 Extended function * Bits 30-24 (bit 22 = 1) Subfunction number - * (bit 22 = 0) Number of consecutive functions to call, minus one + * Bit 30 (bit 22 = 0) Hypervisor function + * Bits 29-24 (bit 22 = 0) Number of consecutive functions to call, minus one * Bit 23 Return result as little-endian (used for strings) * Bit 22 Interpret bits 30-24 as a subfunction number * Bits 21-18 Unused @@ -98,7 +99,7 @@ enum cpuid_flags { * @v tag Setting tag * @ret function Starting function number */ -#define CPUID_FUNCTION( tag ) ( (tag) & 0x800000ffUL ) +#define CPUID_FUNCTION( tag ) ( (tag) & 0xc00000ffUL ) /** * Extract subfunction number from CPUID setting tag @@ -109,6 +110,14 @@ enum cpuid_flags { #define CPUID_SUBFUNCTION( tag ) ( ( (tag) >> 24 ) & 0x7f ) /** + * Extract number of consecutive functions from CPUID setting tag + * + * @v tag Setting tag + * @ret num_functions Number of consecutive functions + */ +#define CPUID_NUM_FUNCTIONS( tag ) ( ( ( (tag) >> 24 ) & 0x3f ) + 1 ) + +/** * Extract register array from CPUID setting tag * * @v tag Setting tag @@ -165,12 +174,13 @@ static int cpuid_settings_fetch ( struct settings *settings, /* Call each function in turn */ function = CPUID_FUNCTION ( setting->tag ); - subfunction = CPUID_SUBFUNCTION ( setting->tag ); if ( setting->tag & CPUID_USE_SUBFUNCTION ) { + function &= ~CPUID_HYPERVISOR; + subfunction = CPUID_SUBFUNCTION ( setting->tag ); num_functions = 1; } else { - num_functions = ( subfunction + 1 ); subfunction = 0; + num_functions = CPUID_NUM_FUNCTIONS ( setting->tag ); } for ( ; num_functions-- ; function++ ) { |