diff options
Diffstat (limited to 'drivers/char/hw_random/via-rng.c')
| -rw-r--r-- | drivers/char/hw_random/via-rng.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c index 868e39fd42e4..f7feae4ebb5e 100644 --- a/drivers/char/hw_random/via-rng.c +++ b/drivers/char/hw_random/via-rng.c @@ -42,6 +42,8 @@ enum { VIA_STRFILT_ENABLE = (1 << 14), VIA_RAWBITS_ENABLE = (1 << 13), VIA_RNG_ENABLE = (1 << 6), + VIA_NOISESRC1 = (1 << 8), + VIA_NOISESRC2 = (1 << 9), VIA_XSTORE_CNT_MASK = 0x0F, VIA_RNG_CHUNK_8 = 0x00, /* 64 rand bits, 64 stored bits */ @@ -119,6 +121,7 @@ static int via_rng_data_read(struct hwrng *rng, u32 *data) static int via_rng_init(struct hwrng *rng) { + struct cpuinfo_x86 *c = &cpu_data(0); u32 lo, hi, old_lo; /* Control the RNG via MSR. Tread lightly and pay very close @@ -134,6 +137,17 @@ static int via_rng_init(struct hwrng *rng) lo &= ~VIA_XSTORE_CNT_MASK; lo &= ~(VIA_STRFILT_ENABLE | VIA_STRFILT_FAIL | VIA_RAWBITS_ENABLE); lo |= VIA_RNG_ENABLE; + lo |= VIA_NOISESRC1; + + /* Enable secondary noise source on CPUs where it is present. */ + + /* Nehemiah stepping 8 and higher */ + if ((c->x86_model == 9) && (c->x86_mask > 7)) + lo |= VIA_NOISESRC2; + + /* Esther */ + if (c->x86_model >= 10) + lo |= VIA_NOISESRC2; if (lo != old_lo) wrmsr(MSR_VIA_RNG, lo, hi); |