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[cpuid] Provide cpuid_supported() to test for supported functions 

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown 2017-01-25 20:57:18 +00:00
parent 70fc25ad6e
commit d37e025b81
4 changed files with 72 additions and 62 deletions
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90
src/arch/x86/core/cpuid.c
View File

@ -24,6 +24,7 @@
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <string.h>
#include <errno.h>
#include <ipxe/cpuid.h>
/** @file
@ -32,15 +33,19 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
*
*/
/** Colour for debug messages */
#define colour 0x861d
/**
* Check whether or not CPUID instruction is supported
*
* @ret is_supported CPUID instruction is supported
* @ret rc Return status code
*/
int cpuid_is_supported ( void ) {
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"
@ -53,7 +58,54 @@ int cpuid_is_supported ( void ) {
"popf\n\t"
: "=&r" ( original ), "=&r" ( inverted )
: "ir" ( CPUID_FLAG ) );
return ( ( original ^ inverted ) & 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 ), &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;
}
/**
@ -62,18 +114,13 @@ int cpuid_is_supported ( void ) {
* @v features x86 CPU features to fill in
*/
static void x86_intel_features ( struct x86_features *features ) {
uint32_t max_level;
uint32_t discard_a;
uint32_t discard_b;
uint32_t discard_c;
uint32_t discard_d;
int rc;
/* Check that features are available via CPUID */
cpuid ( CPUID_VENDOR_ID, &max_level, &discard_b, &discard_c,
&discard_d );
if ( max_level < CPUID_FEATURES ) {
DBGC ( features, "CPUID has no Intel-defined features (max "
"level %08x)\n", max_level );
if ( ( rc = cpuid_supported ( CPUID_FEATURES ) ) != 0 ) {
DBGC ( features, "CPUID has no Intel-defined features\n" );
return;
}
@ -91,22 +138,13 @@ static void x86_intel_features ( struct x86_features *features ) {
* @v features x86 CPU features to fill in
*/
static void x86_amd_features ( struct x86_features *features ) {
uint32_t max_level;
uint32_t discard_a;
uint32_t discard_b;
uint32_t discard_c;
uint32_t discard_d;
int rc;
/* Check that features are available via CPUID */
cpuid ( CPUID_AMD_MAX_FN, &max_level, &discard_b, &discard_c,
&discard_d );
if ( ( max_level & CPUID_AMD_CHECK_MASK ) != CPUID_AMD_CHECK ) {
DBGC ( features, "CPUID has no extended functions\n" );
return;
}
if ( max_level < CPUID_AMD_FEATURES ) {
DBGC ( features, "CPUID has no AMD-defined features (max "
"level %08x)\n", max_level );
if ( ( rc = cpuid_supported ( CPUID_AMD_FEATURES ) ) != 0 ) {
DBGC ( features, "CPUID has no AMD-defined features\n" );
return;
}
@ -127,12 +165,6 @@ void x86_features ( struct x86_features *features ) {
/* Clear all features */
memset ( features, 0, sizeof ( *features ) );
/* Check that CPUID instruction is available */
if ( ! cpuid_is_supported() ) {
DBGC ( features, "CPUID instruction is not supported\n" );
return;
}
/* Get Intel-defined features */
x86_intel_features ( features );

35
src/arch/x86/core/cpuid_settings.c
View File

@ -149,48 +149,25 @@ static int cpuid_settings_fetch ( struct settings *settings,
struct setting *setting,
void *data, size_t len ) {
uint32_t function;
uint32_t max_function;
uint32_t num_functions;
uint32_t registers;
uint32_t num_registers;
uint32_t buf[4];
uint32_t output;
uint32_t discard_b;
uint32_t discard_c;
uint32_t discard_d;
size_t frag_len;
size_t result_len = 0;
/* Fail unless CPUID is supported */
if ( ! cpuid_is_supported() ) {
DBGC ( settings, "CPUID not supported\n" );
return -ENOTSUP;
}
/* Find highest supported function number within this set */
function = CPUID_FUNCTION ( setting->tag );
cpuid ( function & CPUID_EXTENDED, &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 ( settings, "CPUID invalid maximum function\n" );
return -ENOTSUP;
}
int rc;
/* Call each function in turn */
function = CPUID_FUNCTION ( setting->tag );
num_functions = CPUID_NUM_FUNCTIONS ( setting->tag );
for ( ; num_functions-- ; function++ ) {
/* Fail if this function is not supported */
if ( function > max_function ) {
DBGC ( settings, "CPUID function %#08x not supported\n",
function );
return -ENOTSUP;
if ( ( rc = cpuid_supported ( function ) ) != 0 ) {
DBGC ( settings, "CPUID function %#08x not supported: "
"%s\n", function, strerror ( rc ) );
return rc;
}
/* Issue CPUID */

1
src/arch/x86/include/bits/errfile.h
View File

@ -25,6 +25,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#define ERRFILE_gdbmach ( ERRFILE_ARCH | ERRFILE_CORE | 0x000e0000 )
#define ERRFILE_rtc_entropy ( ERRFILE_ARCH | ERRFILE_CORE | 0x000f0000 )
#define ERRFILE_acpipwr ( ERRFILE_ARCH | ERRFILE_CORE | 0x00100000 )
#define ERRFILE_cpuid ( ERRFILE_ARCH | ERRFILE_CORE | 0x00110000 )
#define ERRFILE_bootsector ( ERRFILE_ARCH | ERRFILE_IMAGE | 0x00000000 )
#define ERRFILE_bzimage ( ERRFILE_ARCH | ERRFILE_IMAGE | 0x00010000 )

8
src/arch/x86/include/ipxe/cpuid.h
View File

@ -60,22 +60,22 @@ struct x86_features {
/**
* Issue CPUID instruction
*
* @v operation CPUID operation
* @v function CPUID function
* @v eax Output via %eax
* @v ebx Output via %ebx
* @v ecx Output via %ecx
* @v edx Output via %edx
*/
static inline __attribute__ (( always_inline )) void
cpuid ( uint32_t operation, uint32_t *eax, uint32_t *ebx, uint32_t *ecx,
cpuid ( uint32_t function, uint32_t *eax, uint32_t *ebx, uint32_t *ecx,
uint32_t *edx ) {
__asm__ ( "cpuid"
: "=a" ( *eax ), "=b" ( *ebx ), "=c" ( *ecx ), "=d" ( *edx )
: "0" ( operation ) );
: "0" ( function ) );
}
extern int cpuid_is_supported ( void );
extern int cpuid_supported ( uint32_t function );
extern void x86_features ( struct x86_features *features );
#endif /* _IPXE_CPUID_H */