@@ -603,30 +603,100 @@ static u8 get_rng_vid(ccsr_sec_t *sec)
*/
static void kick_trng(int ent_delay, ccsr_sec_t *sec)
{
+ u32 samples = 512; /* number of bits to generate and test */
+ u32 mono_min = 195;
+ u32 mono_max = 317;
+ u32 mono_range = mono_max - mono_min;
+ u32 poker_min = 1031;
+ u32 poker_max = 1600;
+ u32 poker_range = poker_max - poker_min + 1;
+ u32 retries = 2;
+ u32 lrun_max = 32;
+ s32 run_1_min = 27;
+ s32 run_1_max = 107;
+ s32 run_1_range = run_1_max - run_1_min;
+ s32 run_2_min = 7;
+ s32 run_2_max = 62;
+ s32 run_2_range = run_2_max - run_2_min;
+ s32 run_3_min = 0;
+ s32 run_3_max = 39;
+ s32 run_3_range = run_3_max - run_3_min;
+ s32 run_4_min = -1;
+ s32 run_4_max = 26;
+ s32 run_4_range = run_4_max - run_4_min;
+ s32 run_5_min = -1;
+ s32 run_5_max = 18;
+ s32 run_5_range = run_5_max - run_5_min;
+ s32 run_6_min = -1;
+ s32 run_6_max = 17;
+ s32 run_6_range = run_6_max - run_6_min;
+ u32 val;
+
struct rng4tst __iomem *rng =
(struct rng4tst __iomem *)&sec->rng;
- u32 val;
- /* put RNG4 into program mode */
- sec_setbits32(&rng->rtmctl, RTMCTL_PRGM);
- /* rtsdctl bits 0-15 contain "Entropy Delay, which defines the
- * length (in system clocks) of each Entropy sample taken
- * */
+ /* Put RNG in program mode */
+ /* Setting both RTMCTL:PRGM and RTMCTL:TRNG_ACC causes TRNG to
+ * properly invalidate the entropy in the entropy register and
+ * force re-generation.
+ */
+ sec_setbits32(&rng->rtmctl, RTMCTL_PRGM | RTMCTL_ACC);
+
+ /* Configure the RNG Entropy Delay
+ * Performance-wise, it does not make sense to
+ * set the delay to a value that is lower
+ * than the last one that worked (i.e. the state handles
+ * were instantiated properly. Thus, instead of wasting
+ * time trying to set the values controlling the sample
+ * frequency, the function simply returns.
+ */
val = sec_in32(&rng->rtsdctl);
- val = (val & ~RTSDCTL_ENT_DLY_MASK) |
- (ent_delay << RTSDCTL_ENT_DLY_SHIFT);
+ val &= RTSDCTL_ENT_DLY_MASK;
+ val >>= RTSDCTL_ENT_DLY_SHIFT;
+ if (ent_delay < val) {
+ /* Put RNG4 into run mode */
+ sec_clrbits32(&rng->rtmctl, RTMCTL_PRGM | RTMCTL_ACC);
+ return;
+ }
+
+ val = (ent_delay << RTSDCTL_ENT_DLY_SHIFT) | samples;
sec_out32(&rng->rtsdctl, val);
- /* min. freq. count, equal to 1/4 of the entropy sample length */
- sec_out32(&rng->rtfreqmin, ent_delay >> 2);
- /* disable maximum frequency count */
- sec_out32(&rng->rtfreqmax, RTFRQMAX_DISABLE);
+
+ /*
+ * Recommended margins (min,max) for freq. count:
+ * freq_mul = RO_freq / TRNG_clk_freq
+ * rtfrqmin = (ent_delay x freq_mul) >> 1;
+ * rtfrqmax = (ent_delay x freq_mul) << 3;
+ * Given current deployments of CAAM in i.MX SoCs, and to simplify
+ * the configuration, we consider [1,16] to be a safe interval
+ * for the freq_mul and the limits of the interval are used to compute
+ * rtfrqmin, rtfrqmax
+ */
+ sec_out32(&rng->rtfreqmin, ent_delay >> 1);
+ sec_out32(&rng->rtfreqmax, ent_delay << 7);
+
+ sec_out32(&rng->rtscmisc, (retries << 16) | lrun_max);
+ sec_out32(&rng->rtpkrmax, poker_max);
+ sec_out32(&rng->rtpkrrng, poker_range);
+ sec_out32(&rng->rsvd1[0], (mono_range << 16) | mono_max);
+ sec_out32(&rng->rsvd1[1], (run_1_range << 16) | run_1_max);
+ sec_out32(&rng->rsvd1[2], (run_2_range << 16) | run_2_max);
+ sec_out32(&rng->rsvd1[3], (run_3_range << 16) | run_3_max);
+ sec_out32(&rng->rsvd1[4], (run_4_range << 16) | run_4_max);
+ sec_out32(&rng->rsvd1[5], (run_5_range << 16) | run_5_max);
+ sec_out32(&rng->rsvd1[6], (run_6_range << 16) | run_6_max);
+
+ val = sec_in32(&rng->rtmctl);
/*
- * select raw sampling in both entropy shifter
+ * Select raw sampling in both entropy shifter
* and statistical checker
*/
- sec_setbits32(&rng->rtmctl, RTMCTL_SAMP_MODE_RAW_ES_SC);
- /* put RNG4 into run mode */
- sec_clrbits32(&rng->rtmctl, RTMCTL_PRGM);
+ val &= ~RTMCTL_SAMP_MODE_INVALID;
+ val |= RTMCTL_SAMP_MODE_RAW_ES_SC;
+ /* Put RNG4 into run mode */
+ val &= ~(RTMCTL_PRGM | RTMCTL_ACC);
+ /*test with sample mode only */
+ sec_out32(&rng->rtmctl, val);
}
static int rng_init(uint8_t sec_idx, ccsr_sec_t *sec)
@@ -34,6 +34,7 @@
#if CONFIG_SYS_FSL_SEC_COMPAT >= 4
/* RNG4 TRNG test registers */
struct rng4tst {
+#define RTMCTL_ACC 0x20
#define RTMCTL_PRGM 0x00010000 /* 1 -> program mode, 0 -> run mode */
#define RTMCTL_SAMP_MODE_VON_NEUMANN_ES_SC 0 /* use von Neumann data in
both entropy shifter and