2 * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
29 #include <ipxe/init.h>
30 #include <ipxe/settings.h>
31 #include <ipxe/cpuid.h>
37 * CPUID settings are numerically encoded as:
39 * Bit 31 Extended function
41 * Bits 27-24 Number of consecutive functions to call, minus one
42 * Bit 23 Return result as little-endian (used for strings)
44 * Bits 17-16 Number of registers in register array, minus one
45 * Bits 15-8 Array of register indices. First entry in array is in
46 * bits 9-8. Indices are 0-%eax, 1-%ebx, 2-%ecx, 3-%edx.
47 * Bits 7-0 Starting function number (excluding "extended" bit)
49 * This encoding scheme is designed to allow the common case of
50 * extracting a single register from a single function to be encoded
51 * using "cpuid/<register>.<function>", e.g. "cpuid/2.0x80000001" to
52 * retrieve the value of %ecx from calling CPUID with %eax=0x80000001.
55 /** CPUID setting tag register indices */
56 enum cpuid_registers {
64 * Construct CPUID setting tag
66 * @v function Starting function number
67 * @v num_functions Number of consecutive functions
68 * @v little_endian Return result as little-endian
69 * @v num_registers Number of registers in register array
70 * @v register1 First register in register array (or zero, if empty)
71 * @v register2 Second register in register array (or zero, if empty)
72 * @v register3 Third register in register array (or zero, if empty)
73 * @v register4 Fourth register in register array (or zero, if empty)
74 * @ret tag Setting tag
76 #define CPUID_TAG( function, num_functions, little_endian, num_registers, \
77 register1, register2, register3, register4 ) \
78 ( (function) | ( ( (num_functions) - 1 ) << 24 ) | \
79 ( (little_endian) << 23 ) | ( ( (num_registers) - 1) << 16 ) | \
80 ( (register1) << 8 ) | ( (register2) << 10 ) | \
81 ( (register3) << 12 ) | ( (register4) << 14 ) )
84 * Extract endianness from CPUID setting tag
87 * @ret little_endian Result should be returned as little-endian
89 #define CPUID_LITTLE_ENDIAN( tag ) ( (tag) & 0x00800000UL )
92 * Extract starting function number from CPUID setting tag
95 * @ret function Starting function number
97 #define CPUID_FUNCTION( tag ) ( (tag) & 0x800000ffUL )
100 * Extract number of consecutive functions from CPUID setting tag
103 * @ret num_functions Number of consecutive functions
105 #define CPUID_NUM_FUNCTIONS( tag ) ( ( ( (tag) >> 24 ) & 0xf ) + 1 )
108 * Extract register array from CPUID setting tag
111 * @ret registers Register array
113 #define CPUID_REGISTERS( tag ) ( ( (tag) >> 8 ) & 0xff )
116 * Extract number of registers from CPUID setting tag
119 * @ret num_registers Number of registers within register array
121 #define CPUID_NUM_REGISTERS( tag ) ( ( ( (tag) >> 16 ) & 0x3 ) + 1 )
123 /** CPUID settings scope */
124 static const struct settings_scope cpuid_settings_scope;
127 * Check applicability of CPUID setting
129 * @v settings Settings block
131 * @ret applies Setting applies within this settings block
133 static int cpuid_settings_applies ( struct settings *settings __unused,
134 const struct setting *setting ) {
136 return ( setting->scope == &cpuid_settings_scope );
140 * Fetch value of CPUID setting
142 * @v settings Settings block
143 * @v setting Setting to fetch
144 * @v data Buffer to fill with setting data
145 * @v len Length of buffer
146 * @ret len Length of setting data, or negative error
148 static int cpuid_settings_fetch ( struct settings *settings,
149 struct setting *setting,
150 void *data, size_t len ) {
152 uint32_t max_function;
153 uint32_t num_functions;
155 uint32_t num_registers;
162 size_t result_len = 0;
164 /* Fail unless CPUID is supported */
165 if ( ! cpuid_is_supported() ) {
166 DBGC ( settings, "CPUID not supported\n" );
170 /* Find highest supported function number within this set */
171 function = CPUID_FUNCTION ( setting->tag );
172 cpuid ( function & CPUID_EXTENDED, &max_function, &discard_b,
173 &discard_c, &discard_d );
175 /* Fail if maximum function number is meaningless (e.g. if we
176 * are attempting to call an extended function on a CPU which
177 * does not support them).
179 if ( ( max_function & CPUID_AMD_CHECK_MASK ) !=
180 ( function & CPUID_AMD_CHECK_MASK ) ) {
181 DBGC ( settings, "CPUID invalid maximum function\n" );
185 /* Call each function in turn */
186 num_functions = CPUID_NUM_FUNCTIONS ( setting->tag );
187 for ( ; num_functions-- ; function++ ) {
189 /* Fail if this function is not supported */
190 if ( function > max_function ) {
191 DBGC ( settings, "CPUID function %#08x not supported\n",
197 cpuid ( function, &buf[CPUID_EAX], &buf[CPUID_EBX],
198 &buf[CPUID_ECX], &buf[CPUID_EDX] );
199 DBGC ( settings, "CPUID %#08x => %#08x:%#08x:%#08x:%#08x\n",
200 function, buf[0], buf[1], buf[2], buf[3] );
202 /* Copy results to buffer */
203 registers = CPUID_REGISTERS ( setting->tag );
204 num_registers = CPUID_NUM_REGISTERS ( setting->tag );
205 for ( ; num_registers-- ; registers >>= 2 ) {
206 output = buf[ registers & 0x3 ];
207 if ( ! CPUID_LITTLE_ENDIAN ( setting->tag ) )
208 output = cpu_to_be32 ( output );
209 frag_len = sizeof ( output );
210 if ( frag_len > len )
212 memcpy ( data, &output, frag_len );
215 result_len += sizeof ( output );
219 /* Set type if not already specified */
220 if ( ! setting->type )
221 setting->type = &setting_type_hexraw;
226 /** CPUID settings operations */
227 static struct settings_operations cpuid_settings_operations = {
228 .applies = cpuid_settings_applies,
229 .fetch = cpuid_settings_fetch,
232 /** CPUID settings */
233 static struct settings cpuid_settings = {
235 .siblings = LIST_HEAD_INIT ( cpuid_settings.siblings ),
236 .children = LIST_HEAD_INIT ( cpuid_settings.children ),
237 .op = &cpuid_settings_operations,
238 .default_scope = &cpuid_settings_scope,
241 /** Initialise CPUID settings */
242 static void cpuid_settings_init ( void ) {
245 if ( ( rc = register_settings ( &cpuid_settings, NULL,
247 DBG ( "CPUID could not register settings: %s\n",
253 /** CPUID settings initialiser */
254 struct init_fn cpuid_settings_init_fn __init_fn ( INIT_NORMAL ) = {
255 .initialise = cpuid_settings_init,
258 /** CPU vendor setting */
259 const struct setting cpuvendor_setting __setting ( SETTING_HOST_EXTRA,
262 .description = "CPU vendor",
263 .tag = CPUID_TAG ( CPUID_VENDOR_ID, 1, 1, 3,
264 CPUID_EBX, CPUID_EDX, CPUID_ECX, 0 ),
265 .type = &setting_type_string,
266 .scope = &cpuid_settings_scope,
269 /** CPU model setting */
270 const struct setting cpumodel_setting __setting ( SETTING_HOST_EXTRA,
273 .description = "CPU model",
274 .tag = CPUID_TAG ( CPUID_MODEL, 3, 1, 4,
275 CPUID_EAX, CPUID_EBX, CPUID_ECX, CPUID_EDX ),
276 .type = &setting_type_string,
277 .scope = &cpuid_settings_scope,