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);