openssl/crypto/ppccap.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <setjmp.h>
#include <signal.h>
#include <unistd.h>
#include <crypto.h>
#include <openssl/bn.h>

#define PPC_FPU64       (1<<0)
#define PPC_ALTIVEC     (1<<1)

static int OPENSSL_ppccap_P = 0;

static sigset_t all_masked;

#ifdef OPENSSL_BN_ASM_MONT
int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
                const BN_ULONG *np, const BN_ULONG *n0, int num)
{
    int bn_mul_mont_fpu64(BN_ULONG *rp, const BN_ULONG *ap,
                          const BN_ULONG *bp, const BN_ULONG *np,
                          const BN_ULONG *n0, int num);
    int bn_mul_mont_int(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
                        const BN_ULONG *np, const BN_ULONG *n0, int num);

    if (sizeof(size_t) == 4) {
# if (defined(__APPLE__) && defined(__MACH__))
        if (num >= 8 && (num & 3) == 0 && (OPENSSL_ppccap_P & PPC_FPU64))
            return bn_mul_mont_fpu64(rp, ap, bp, np, n0, num);
# else
        /*
         * boundary of 32 was experimentally determined on Linux 2.6.22,
         * might have to be adjusted on AIX...
         */
        if (num >= 32 && (num & 3) == 0 && (OPENSSL_ppccap_P & PPC_FPU64)) {
            sigset_t oset;
            int ret;

            sigprocmask(SIG_SETMASK, &all_masked, &oset);
            ret = bn_mul_mont_fpu64(rp, ap, bp, np, n0, num);
            sigprocmask(SIG_SETMASK, &oset, NULL);

            return ret;
        }
# endif
    } else if ((OPENSSL_ppccap_P & PPC_FPU64))
        /*
         * this is a "must" on POWER6, but run-time detection is not
         * implemented yet...
         */
        return bn_mul_mont_fpu64(rp, ap, bp, np, n0, num);

    return bn_mul_mont_int(rp, ap, bp, np, n0, num);
}
#endif

static sigjmp_buf ill_jmp;
static void ill_handler(int sig)
{
    siglongjmp(ill_jmp, sig);
}

void OPENSSL_ppc64_probe(void);
void OPENSSL_altivec_probe(void);

void OPENSSL_cpuid_setup(void)
{
    char *e;
    struct sigaction ill_oact, ill_act;
    sigset_t oset;
    static int trigger = 0;

    if (trigger)
        return;
    trigger = 1;

    sigfillset(&all_masked);
    sigdelset(&all_masked, SIGILL);
    sigdelset(&all_masked, SIGTRAP);
#ifdef SIGEMT
    sigdelset(&all_masked, SIGEMT);
#endif
    sigdelset(&all_masked, SIGFPE);
    sigdelset(&all_masked, SIGBUS);
    sigdelset(&all_masked, SIGSEGV);

    if ((e = getenv("OPENSSL_ppccap"))) {
        OPENSSL_ppccap_P = strtoul(e, NULL, 0);
        return;
    }

    OPENSSL_ppccap_P = 0;

#if defined(_AIX)
    if (sizeof(size_t) == 4
# if defined(_SC_AIX_KERNEL_BITMODE)
        && sysconf(_SC_AIX_KERNEL_BITMODE) != 64
# endif
        )
        return;
#endif

    memset(&ill_act, 0, sizeof(ill_act));
    ill_act.sa_handler = ill_handler;
    ill_act.sa_mask = all_masked;

    sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
    sigaction(SIGILL, &ill_act, &ill_oact);

    if (sizeof(size_t) == 4) {
        if (sigsetjmp(ill_jmp, 1) == 0) {
            OPENSSL_ppc64_probe();
            OPENSSL_ppccap_P |= PPC_FPU64;
        }
    } else {
        /*
         * Wanted code detecting POWER6 CPU and setting PPC_FPU64
         */
    }

    if (sigsetjmp(ill_jmp, 1) == 0) {
        OPENSSL_altivec_probe();
        OPENSSL_ppccap_P |= PPC_ALTIVEC;
    }

    sigaction(SIGILL, &ill_oact, NULL);
    sigprocmask(SIG_SETMASK, &oset, NULL);
}