static int via_rng_data_present(struct hwrng *rng, int wait)
{
u32 bytes_out;
u32 *via_rng_datum = (u32 *)(&rng->priv);
int i;
/* We choose the recommended 1-byte-per-instruction RNG rate,
* for greater randomness at the expense of speed. Larger
* values 2, 4, or 8 bytes-per-instruction yield greater
* speed at lesser randomness.
*
* If you change this to another VIA_CHUNK_n, you must also
* change the ->n_bytes values in rng_vendor_ops[] tables.
* VIA_CHUNK_8 requires further code changes.
*
* A copy of MSR_VIA_RNG is placed in eax_out when xstore
* completes.
*/
for (i = 0; i < 20; i++) {
*via_rng_datum = 0; /* paranoia, not really necessary */
bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
bytes_out &= VIA_XSTORE_CNT_MASK;
if (bytes_out || !wait)
break;
udelay(10);
}
return bytes_out ? 1 : 0;
}
/*
* fcdriver version of xstore, replaces base 'x!'
*/
static void
fcd_xstore(fcode_env_t *env)
{
fstack_t addr = TOS;
CHECK_DEPTH(env, 2, "x!");
if (!check_address_abuse(env, addr, "x!", 0, rxstore))
xstore(env);
}
