crypto/riscvcap.c

   1 /*
   2  * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <ctype.h>
  13 #include <stdint.h>
  14 #include <openssl/crypto.h>
  15 #include "internal/cryptlib.h"
  16
  17 #define OPENSSL_RISCVCAP_IMPL
  18 #include "crypto/riscv_arch.h"
  19
  20 extern size_t riscv_vlen_asm(void);
  21
  22 static void parse_env(const char *envstr);
  23 static void strtoupper(char *str);
  24
  25 static size_t vlen = 0;
  26
  27 uint32_t OPENSSL_rdtsc(void)
  28 {
  29     return 0;
  30 }
  31
  32 size_t OPENSSL_instrument_bus(unsigned int *out, size_t cnt)
  33 {
  34     return 0;
  35 }
  36
  37 size_t OPENSSL_instrument_bus2(unsigned int *out, size_t cnt, size_t max)
  38 {
  39     return 0;
  40 }
  41
  42 static void strtoupper(char *str)
  43 {
  44     for (char *x = str; *x; ++x)
  45         *x = toupper(*x);
  46 }
  47
  48 /* parse_env() parses a RISC-V architecture string. An example of such a string
  49  * is "rv64gc_zba_zbb_zbc_zbs". Currently, the rv64gc part is ignored
  50  * and we simply search for "_[extension]" in the arch string to see if we
  51  * should enable a given extension.
  52  */
  53 #define BUFLEN 256
  54 static void parse_env(const char *envstr)
  55 {
  56     char envstrupper[BUFLEN];
  57     char buf[BUFLEN];
  58
  59     /* Convert env str to all uppercase */
  60     OPENSSL_strlcpy(envstrupper, envstr, sizeof(envstrupper));
  61     strtoupper(envstrupper);
  62
  63     for (size_t i = 0; i < kRISCVNumCaps; ++i) {
  64         /* Prefix capability with underscore in preparation for search */
  65         BIO_snprintf(buf, BUFLEN, "_%s", RISCV_capabilities[i].name);
  66         if (strstr(envstrupper, buf) != NULL) {
  67             /* Match, set relevant bit in OPENSSL_riscvcap_P[] */
  68             OPENSSL_riscvcap_P[RISCV_capabilities[i].index] |=
  69                 (1 << RISCV_capabilities[i].bit_offset);
  70         }
  71     }
  72 }
  73
  74 size_t riscv_vlen(void)
  75 {
  76     return vlen;
  77 }
  78
  79 # if defined(__GNUC__) && __GNUC__>=2
  80 __attribute__ ((constructor))
  81 # endif
  82 void OPENSSL_cpuid_setup(void)
  83 {
  84     char *e;
  85     static int trigger = 0;
  86
  87     if (trigger != 0)
  88         return;
  89     trigger = 1;
  90
  91     if ((e = getenv("OPENSSL_riscvcap"))) {
  92         parse_env(e);
  93     }
  94
  95     if (RISCV_HAS_V()) {
  96         vlen = riscv_vlen_asm();
  97     }
  98 }