// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
typedef unsigned int u32;
typedef unsigned long long u64;
char *def_csv = "/usr/share/misc/cpuid.csv";
char *user_csv;
/* Cover both single-bit flag and multiple-bits fields */
struct bits_desc {
/* start and end bits */
int start, end;
/* 0 or 1 for 1-bit flag */
int value;
char simp[32];
char detail[256];
};
/* descriptor info for eax/ebx/ecx/edx */
struct reg_desc {
/* number of valid entries */
int nr;
struct bits_desc descs[32];
};
enum cpuid_reg {
R_EAX = 0,
R_EBX,
R_ECX,
R_EDX,
NR_REGS
};
static const char * const reg_names[] = {
"EAX", "EBX", "ECX", "EDX",
};
struct subleaf {
u32 index;
u32 sub;
u32 eax, ebx, ecx, edx;
struct reg_desc info[NR_REGS];
};
/* Represent one leaf (basic or extended) */
struct cpuid_func {
/*
* Array of subleafs for this func, if there is no subleafs
* then the leafs[0] is the main leaf
*/
struct subleaf *leafs;
int nr;
};
struct cpuid_range {
/* array of main leafs */
struct cpuid_func *funcs;
/* number of valid leafs */
int nr;
bool is_ext;
};
/*
* basic: basic functions range: [0... ]
* ext: extended functions range: [0x80000000... ]
*/
struct cpuid_range *leafs_basic, *leafs_ext;
static int num_leafs;
static bool is_amd;
static bool show_details;
static bool show_raw;
static bool show_flags_only = true;
static u32 user_index = 0xFFFFFFFF;
static u32 user_sub = 0xFFFFFFFF;
static int flines;
static inline void cpuid(u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
{
/* ecx is often an input as well as an output. */
asm volatile("cpuid"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (*eax), "2" (*ecx));
}
static inline bool has_subleafs(u32 f)
{
if (f == 0x7 || f == 0xd)
return true;
if (is_amd) {
if (f == 0x8000001d)
return true;
return false;
}
switch (f) {
case 0x4:
case 0xb:
case 0xf:
case 0x10:
case 0x14:
case 0x18:
case 0x1f:
return true;
default:
return false;
}
}
static void leaf_print_raw(struct subleaf *leaf)
{
if (has_subleafs(leaf->index)) {
if (leaf->sub == 0)
printf("0x%08x: subleafs:\n", leaf->index);
printf(" %2d: EAX=0x%08x, EBX=0x%08x, ECX=0x%08x, EDX=0x%08x\n",
leaf->sub, leaf->eax, leaf->ebx, leaf->ecx, leaf->edx);
} else {
printf("0x%08x: EAX=0x%08x, EBX=0x%08x, ECX=0x%08x, EDX=0x%08x\n",
leaf->index, leaf->eax, leaf->ebx, leaf->ecx, leaf->edx);
}
}
/* Return true is the input eax/ebx/ecx/edx are all zero */
static bool cpuid_store(struct cpuid_range *range, u32 f, int subleaf,
u32 a, u32 b, u32 c, u32 d)
{
struct cpuid_func *func;
struct subleaf *leaf;
int s = 0;
if (a == 0 && b == 0 && c == 0 && d == 0)
return true;
/*
* Cut off vendor-prefix from CPUID function as we're using it as an
* index into ->funcs.
*/
func = &range->funcs[f & 0xffff];
if (!func->leafs) {
func->leafs = malloc(sizeof(struct subleaf));
if (!func->leafs)
perror("malloc func leaf");
func->nr = 1;
} else {
s = func->nr;
func->leafs = realloc(func->leafs, (s + 1) * sizeof(*leaf));
if (!func->leafs)
perror("realloc f->leafs");
func->nr++;
}
leaf = &func->leafs[s];
leaf->index = f;
leaf->sub = subleaf;
leaf->eax = a;
leaf->ebx = b;
leaf->ecx = c;
leaf->edx = d;
return false;
}
static void raw_dump_range(struct cpuid_range *range)
{
u32 f;
int i;
printf("%s Leafs :\n", range->is_ext ? "Extended" : "Basic");
printf("================\n");
for (f = 0; (int)f < range->nr; f++) {
struct cpuid_func *func = &range->funcs[f];
u32 index = f;
if (range->is_ext)
index += 0x80000000;
/* Skip leaf without valid items */
if (!func->nr)
continue;
/* First item is the main leaf, followed by all subleafs */
for (i = 0; i < func->nr; i++)
leaf_print_raw(&func->leafs[i]);
}
}
#define MAX_SUBLEAF_NUM 32
struct cpuid_range *setup_cpuid_range(u32 input_eax)
{
u32 max_func, idx_func;
int subleaf;
struct cpuid_range *range;
u32 eax, ebx, ecx, edx;
u32 f = input_eax;
int max_subleaf;
bool allzero;
eax = input_eax;
ebx = ecx = edx = 0;
cpuid(&eax, &ebx, &ecx, &edx);
max_func = eax;
idx_func = (max_func & 0xffff) + 1;
range = malloc(sizeof(struct cpuid_range));
if (!range)
perror("malloc range");
if (input_eax & 0x80000000)
range->is_ext = true;
else
range->is_ext = false;
range->funcs = malloc(sizeof(struct cpuid_func) * idx_func);
if (!range->funcs)
perror("malloc range->funcs");
range->nr = idx_func;
memset(range->funcs, 0, sizeof(struct cpuid_func) * idx_func);
for (; f <= max_func; f++) {
eax = f;
subleaf = ecx = 0;
cpuid(&eax, &ebx, &ecx, &edx);
allzero = cpuid_store(range, f, subleaf, eax, ebx, ecx, edx);
if (allzero)
continue;
num_leafs++;
if (!has_subleafs(f))
continue;
max_subleaf = MAX_SUBLEAF_NUM;
/*
* Some can provide the exact number of subleafs,
* others have to be tried (0xf)
*/
if (f == 0x7 || f == 0x14 || f == 0x17 || f == 0x18)
max_subleaf = (eax & 0xff) + 1;
if (f == 0xb)
max_subleaf = 2;
for (subleaf = 1; subleaf < max_subleaf; subleaf++) {
eax = f;
ecx = subleaf;
cpuid(&eax, &ebx, &ecx, &edx);
allzero = cpuid_store(range, f, subleaf,
eax, ebx, ecx, edx);
if (allzero)
continue;
num_leafs++;
}
}
return range;
}
/*
* The basic row format for cpuid.csv is
* LEAF,SUBLEAF,register_name,bits,short name,long description
*
* like:
* 0, 0, EAX, 31:0, max_basic_leafs, Max input value for supported subleafs
* 1, 0, ECX, 0, sse3, Streaming SIMD Extensions 3(SSE3)
*/
static int parse_line(char *line)
{
char *str;
int i;
struct cpuid_range *range;
struct cpuid_func *func;
struct subleaf *leaf;
u32 index;
u32 sub;
char buffer[512];
char *buf;
/*
* Tokens:
* 1. leaf
* 2. subleaf
* 3. register
* 4. bits
* 5. short name
* 6. long detail
*/
char *tokens[6];
struct reg_desc *reg;
struct bits_desc *bdesc;
int reg_index;
char *start, *end;
/* Skip comments and NULL line */
if (line[0] == '#' || line[0] == '\n')
return 0;
strncpy(buffer, line, 511);
buffer[511] = 0;
str = buffer;
for (i = 0; i < 5; i++) {
tokens[i] = strtok(str, ",");
if (!tokens[i])
goto err_exit;
str = NULL;
}
tokens[5] = strtok(str, "\n");
if (!tokens[5])
goto err_exit;
/* index/main-leaf */
index = strtoull(tokens[0], NULL, 0);
if (index & 0x80000000)
range = leafs_ext;
else
range = leafs_basic;
index &= 0x7FFFFFFF;
/* Skip line parsing for non-existing indexes */
if ((int)index >= range->nr)
return -1;
func = &range->funcs[index];
/* Return if the index has no valid item on this platform */
if (!func->nr)
return 0;
/* subleaf */
sub = strtoul(tokens[1], NULL, 0);
if ((int)sub > func->nr)
return -1;
leaf = &func->leafs[sub];
buf = tokens[2];
if (strcasestr(buf, "EAX"))
reg_index = R_EAX;
else if (strcasestr(buf, "EBX"))
reg_index = R_EBX;
else if (strcasestr(buf, "ECX"))
reg_index = R_ECX;
else if (strcasestr(buf, "EDX"))
reg_index = R_EDX;
else
goto err_exit;
reg = &leaf->info[reg_index];
bdesc = ®->descs[reg->nr++];
/* bit flag or bits field */
buf = tokens[3];
end = strtok(buf, ":");
bdesc->end = strtoul(end, NULL, 0);
bdesc->start = bdesc->end;
/* start != NULL means it is bit fields */
start = strtok(NULL, ":");
if (start)
bdesc->start = strtoul(start, NULL, 0);
strcpy(bdesc->simp, tokens[4]);
strcpy(bdesc->detail, tokens[5]);
return 0;
err_exit:
printf("Warning: wrong line format:\n");
printf("\tline[%d]: %s\n", flines, line);
return -1;
}
/* Parse csv file, and construct the array of all leafs and subleafs */
static void parse_text(void)
{
FILE *file;
char *filename, *line = NULL;
size_t len = 0;
int ret;
if (show_raw)
return;
filename = user_csv ? user_csv : def_csv;
file = fopen(filename, "r");
if (!file) {
/* Fallback to a csv in the same dir */
file = fopen("./cpuid.csv", "r");
}
if (!file) {
printf("Fail to open '%s'\n", filename);
return;
}
while (1) {
ret = getline(&line, &len, file);
flines++;
if (ret > 0)
parse_line(line);
if (feof(file))
break;
}
fclose(file);
}
/* Decode every eax/ebx/ecx/edx */
static void decode_bits(u32 value, struct reg_desc *rdesc, enum cpuid_reg reg)
{
struct bits_desc *bdesc;
int start, end, i;
u32 mask;
if (!rdesc->nr) {
if (show_details)
printf("\t %s: 0x%08x\n", reg_names[reg], value);
return;
}
for (i = 0; i < rdesc->nr; i++) {
bdesc = &rdesc->descs[i];
start = bdesc->start;
end = bdesc->end;
if (start == end) {
/* single bit flag */
if (value & (1 << start))
printf("\t%-20s %s%s\n",
bdesc->simp,
show_details ? "-" : "",
show_details ? bdesc->detail : ""
);
} else {
/* bit fields */
if (show_flags_only)
continue;
mask = ((u64)1 << (end - start + 1)) - 1;
printf("\t%-20s\t: 0x%-8x\t%s%s\n",
bdesc->simp,
(value >> start) & mask,
show_details ? "-" : "",
show_details ? bdesc->detail : ""
);
}
}
}
static void show_leaf(struct subleaf *leaf)
{
if (!leaf)
return;
if (show_raw) {
leaf_print_raw(leaf);
} else {
if (show_details)
printf("CPUID_0x%x_ECX[0x%x]:\n",
leaf->index, leaf->sub);
}
decode_bits(leaf->eax, &leaf->info[R_EAX], R_EAX);
decode_bits(leaf->ebx, &leaf->info[R_EBX], R_EBX);
decode_bits(leaf->ecx, &leaf->info[R_ECX], R_ECX);
decode_bits(leaf->edx, &leaf->info[R_EDX], R_EDX);
if (!show_raw && show_details)
printf("\n");
}
static void show_func(struct cpuid_func *func)
{
int i;
if (!func)
return;
for (i = 0; i < func->nr; i++)
show_leaf(&func->leafs[i]);
}
static void show_range(struct cpuid_range *range)
{
int i;
for (i = 0; i < range->nr; i++)
show_func(&range->funcs[i]);
}
static inline struct cpuid_func *index_to_func(u32 index)
{
struct cpuid_range *range;
u32 func_idx;
range = (index & 0x80000000) ? leafs_ext : leafs_basic;
func_idx = index & 0xffff;
if ((func_idx + 1) > (u32)range->nr) {
printf("ERR: invalid input index (0x%x)\n", index);
return NULL;
}
return &range->funcs[func_idx];
}
static void show_info(void)
{
struct cpuid_func *func;
if (show_raw) {
/* Show all of the raw output of 'cpuid' instr */
raw_dump_range(leafs_basic);
raw_dump_range(leafs_ext);
return;
}
if (user_index != 0xFFFFFFFF) {
/* Only show specific leaf/subleaf info */
func = index_to_func(user_index);
if (!func)
return;
/* Dump the raw data also */
show_raw = true;
if (user_sub != 0xFFFFFFFF) {
if (user_sub + 1 <= (u32)func->nr) {
show_leaf(&func->leafs[user_sub]);
return;
}
printf("ERR: invalid input subleaf (0x%x)\n", user_sub);
}
show_func(func);
return;
}
printf("CPU features:\n=============\n\n");
show_range(leafs_basic);
show_range(leafs_ext);
}
static void setup_platform_cpuid(void)
{
u32 eax, ebx, ecx, edx;
/* Check vendor */
eax = ebx = ecx = edx = 0;
cpuid(&eax, &ebx, &ecx, &edx);
/* "htuA" */
if (ebx == 0x68747541)
is_amd = true;
/* Setup leafs for the basic and extended range */
leafs_basic = setup_cpuid_range(0x0);
leafs_ext = setup_cpuid_range(0x80000000);
}
static void usage(void)
{
printf("kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
"\t-a|--all Show both bit flags and complex bit fields info\n"
"\t-b|--bitflags Show boolean flags only\n"
"\t-d|--detail Show details of the flag/fields (default)\n"
"\t-f|--flags Specify the cpuid csv file\n"
"\t-h|--help Show usage info\n"
"\t-l|--leaf=index Specify the leaf you want to check\n"
"\t-r|--raw Show raw cpuid data\n"
"\t-s|--subleaf=sub Specify the subleaf you want to check\n"
);
}
static struct option opts[] = {
{ "all", no_argument, NULL, 'a' }, /* show both bit flags and fields */
{ "bitflags", no_argument, NULL, 'b' }, /* only show bit flags, default on */
{ "detail", no_argument, NULL, 'd' }, /* show detail descriptions */
{ "file", required_argument, NULL, 'f' }, /* use user's cpuid file */
{ "help", no_argument, NULL, 'h'}, /* show usage */
{ "leaf", required_argument, NULL, 'l'}, /* only check a specific leaf */
{ "raw", no_argument, NULL, 'r'}, /* show raw CPUID leaf data */
{ "subleaf", required_argument, NULL, 's'}, /* check a specific subleaf */
{ NULL, 0, NULL, 0 }
};
static int parse_options(int argc, char *argv[])
{
int c;
while ((c = getopt_long(argc, argv, "abdf:hl:rs:",
opts, NULL)) != -1)
switch (c) {
case 'a':
show_flags_only = false;
break;
case 'b':
show_flags_only = true;
break;
case 'd':
show_details = true;
break;
case 'f':
user_csv = optarg;
break;
case 'h':
usage();
exit(1);
break;
case 'l':
/* main leaf */
user_index = strtoul(optarg, NULL, 0);
break;
case 'r':
show_raw = true;
break;
case 's':
/* subleaf */
user_sub = strtoul(optarg, NULL, 0);
break;
default:
printf("%s: Invalid option '%c'\n", argv[0], optopt);
return -1;
}
return 0;
}
/*
* Do 4 things in turn:
* 1. Parse user options
* 2. Parse and store all the CPUID leaf data supported on this platform
* 2. Parse the csv file, while skipping leafs which are not available
* on this platform
* 3. Print leafs info based on user options
*/
int main(int argc, char *argv[])
{
if (parse_options(argc, argv))
return -1;
/* Setup the cpuid leafs of current platform */
setup_platform_cpuid();
/* Read and parse the 'cpuid.csv' */
parse_text();
show_info();
return 0;
}