[PATCH 3/4] n2rng: support new hardware register layout

From: Shannon Nelson
Date: Thu Jan 12 2017 - 13:54:21 EST

Next message: Nicholas Mc Guire: "Re: [PATCH] Input: silead: use msleep() for long delays"
Previous message: Shannon Nelson: "[PATCH 4/4] n2rng: update version info"
In reply to: Shannon Nelson: "[PATCH 4/4] n2rng: update version info"
Next in thread: Herbert Xu: "Re: [PATCH 0/4] n2rng: add support for m5/m7 rng register layout"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Add the new register layout constants and the requisite logic
for using them.

Signed-off-by: Shannon Nelson <shannon.nelson@xxxxxxxxxx>
---
drivers/char/hw_random/n2-drv.c | 144 +++++++++++++++++++++++++++++----------
drivers/char/hw_random/n2rng.h | 36 +++++++---
2 files changed, 134 insertions(+), 46 deletions(-)

diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 74c26c7..f0bd5ee 100644
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -302,26 +302,57 @@ static int n2rng_try_read_ctl(struct n2rng *np)
return n2rng_hv_err_trans(hv_err);
}

-#define CONTROL_DEFAULT_BASE \
- ((2 << RNG_CTL_ASEL_SHIFT) | \
- (N2RNG_ACCUM_CYCLES_DEFAULT << RNG_CTL_WAIT_SHIFT) | \
- RNG_CTL_LFSR)
-
-#define CONTROL_DEFAULT_0 \
- (CONTROL_DEFAULT_BASE | \
- (1 << RNG_CTL_VCO_SHIFT) | \
- RNG_CTL_ES1)
-#define CONTROL_DEFAULT_1 \
- (CONTROL_DEFAULT_BASE | \
- (2 << RNG_CTL_VCO_SHIFT) | \
- RNG_CTL_ES2)
-#define CONTROL_DEFAULT_2 \
- (CONTROL_DEFAULT_BASE | \
- (3 << RNG_CTL_VCO_SHIFT) | \
- RNG_CTL_ES3)
-#define CONTROL_DEFAULT_3 \
- (CONTROL_DEFAULT_BASE | \
- RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3)
+static u64 n2rng_control_default(struct n2rng *np, int ctl)
+{
+ u64 val = 0;
+
+ if (np->data->chip_version == 1) {
+ val = ((2 << RNG_v1_CTL_ASEL_SHIFT) |
+ (N2RNG_ACCUM_CYCLES_DEFAULT << RNG_v1_CTL_WAIT_SHIFT) |
+ RNG_CTL_LFSR);
+
+ switch (ctl) {
+ case 0:
+ val |= (1 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES1;
+ break;
+ case 1:
+ val |= (2 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES2;
+ break;
+ case 2:
+ val |= (3 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES3;
+ break;
+ case 3:
+ val |= RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3;
+ break;
+ default:
+ break;
+ }
+
+ } else {
+ val = ((2 << RNG_v2_CTL_ASEL_SHIFT) |
+ (N2RNG_ACCUM_CYCLES_DEFAULT << RNG_v2_CTL_WAIT_SHIFT) |
+ RNG_CTL_LFSR);
+
+ switch (ctl) {
+ case 0:
+ val |= (1 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES1;
+ break;
+ case 1:
+ val |= (2 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES2;
+ break;
+ case 2:
+ val |= (3 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES3;
+ break;
+ case 3:
+ val |= RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3;
+ break;
+ default:
+ break;
+ }
+ }
+
+ return val;
+}

static void n2rng_control_swstate_init(struct n2rng *np)
{
@@ -336,10 +367,10 @@ static void n2rng_control_swstate_init(struct n2rng *np)
for (i = 0; i < np->num_units; i++) {
struct n2rng_unit *up = &np->units[i];

- up->control[0] = CONTROL_DEFAULT_0;
- up->control[1] = CONTROL_DEFAULT_1;
- up->control[2] = CONTROL_DEFAULT_2;
- up->control[3] = CONTROL_DEFAULT_3;
+ up->control[0] = n2rng_control_default(np, 0);
+ up->control[1] = n2rng_control_default(np, 1);
+ up->control[2] = n2rng_control_default(np, 2);
+ up->control[3] = n2rng_control_default(np, 3);
}

np->hv_state = HV_RNG_STATE_UNCONFIGURED;
@@ -399,6 +430,7 @@ static int n2rng_data_read(struct hwrng *rng, u32 *data)
} else {
int err = n2rng_generic_read_data(ra);
if (!err) {
+ np->flags |= N2RNG_FLAG_BUFFER_VALID;
np->buffer = np->test_data >> 32;
*data = np->test_data & 0xffffffff;
len = 4;
@@ -487,9 +519,21 @@ static void n2rng_dump_test_buffer(struct n2rng *np)

static int n2rng_check_selftest_buffer(struct n2rng *np, unsigned long unit)
{
- u64 val = SELFTEST_VAL;
+ u64 val;
int err, matches, limit;

+ switch (np->data->id) {
+ case N2_n2_rng:
+ case N2_vf_rng:
+ case N2_kt_rng:
+ case N2_m4_rng: /* yes, m4 uses the old value */
+ val = RNG_v1_SELFTEST_VAL;
+ break;
+ default:
+ val = RNG_v2_SELFTEST_VAL;
+ break;
+ }
+
matches = 0;
for (limit = 0; limit < SELFTEST_LOOPS_MAX; limit++) {
matches += n2rng_test_buffer_find(np, val);
@@ -512,14 +556,32 @@ static int n2rng_check_selftest_buffer(struct n2rng *np, unsigned long unit)
static int n2rng_control_selftest(struct n2rng *np, unsigned long unit)
{
int err;
+ u64 base, base3;
+
+ switch (np->data->id) {
+ case N2_n2_rng:
+ case N2_vf_rng:
+ case N2_kt_rng:
+ base = RNG_v1_CTL_ASEL_NOOUT << RNG_v1_CTL_ASEL_SHIFT;
+ base3 = base | RNG_CTL_LFSR |
+ ((RNG_v1_SELFTEST_TICKS - 2) << RNG_v1_CTL_WAIT_SHIFT);
+ break;
+ case N2_m4_rng:
+ base = RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT;
+ base3 = base | RNG_CTL_LFSR |
+ ((RNG_v1_SELFTEST_TICKS - 2) << RNG_v2_CTL_WAIT_SHIFT);
+ break;
+ default:
+ base = RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT;
+ base3 = base | RNG_CTL_LFSR |
+ (RNG_v2_SELFTEST_TICKS << RNG_v2_CTL_WAIT_SHIFT);
+ break;
+ }

- np->test_control[0] = (0x2 << RNG_CTL_ASEL_SHIFT);
- np->test_control[1] = (0x2 << RNG_CTL_ASEL_SHIFT);
- np->test_control[2] = (0x2 << RNG_CTL_ASEL_SHIFT);
- np->test_control[3] = ((0x2 << RNG_CTL_ASEL_SHIFT) |
- RNG_CTL_LFSR |
- ((SELFTEST_TICKS - 2) << RNG_CTL_WAIT_SHIFT));
-
+ np->test_control[0] = base;
+ np->test_control[1] = base;
+ np->test_control[2] = base;
+ np->test_control[3] = base3;

err = n2rng_entropy_diag_read(np, unit, np->test_control,
HV_RNG_STATE_HEALTHCHECK,
@@ -557,11 +619,19 @@ static int n2rng_control_configure_units(struct n2rng *np)
struct n2rng_unit *up = &np->units[unit];
unsigned long ctl_ra = __pa(&up->control[0]);
int esrc;
- u64 base;
+ u64 base, shift;

- base = ((np->accum_cycles << RNG_CTL_WAIT_SHIFT) |
- (2 << RNG_CTL_ASEL_SHIFT) |
- RNG_CTL_LFSR);
+ if (np->data->chip_version == 1) {
+ base = ((np->accum_cycles << RNG_v1_CTL_WAIT_SHIFT) |
+ (RNG_v1_CTL_ASEL_NOOUT << RNG_v1_CTL_ASEL_SHIFT) |
+ RNG_CTL_LFSR);
+ shift = RNG_v1_CTL_VCO_SHIFT;
+ } else {
+ base = ((np->accum_cycles << RNG_v2_CTL_WAIT_SHIFT) |
+ (RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT) |
+ RNG_CTL_LFSR);
+ shift = RNG_v2_CTL_VCO_SHIFT;
+ }

/* XXX This isn't the best. We should fetch a bunch
* XXX of words using each entropy source combined XXX
@@ -570,7 +640,7 @@ static int n2rng_control_configure_units(struct n2rng *np)
*/
for (esrc = 0; esrc < 3; esrc++)
up->control[esrc] = base |
- (esrc << RNG_CTL_VCO_SHIFT) |
+ (esrc << shift) |
(RNG_CTL_ES1 << esrc);

up->control[3] = base |
diff --git a/drivers/char/hw_random/n2rng.h b/drivers/char/hw_random/n2rng.h
index e41e55a..6bad6cc 100644
--- a/drivers/char/hw_random/n2rng.h
+++ b/drivers/char/hw_random/n2rng.h
@@ -6,18 +6,34 @@
#ifndef _N2RNG_H
#define _N2RNG_H

-#define RNG_CTL_WAIT 0x0000000001fffe00ULL /* Minimum wait time */
-#define RNG_CTL_WAIT_SHIFT 9
-#define RNG_CTL_BYPASS 0x0000000000000100ULL /* VCO voltage source */
-#define RNG_CTL_VCO 0x00000000000000c0ULL /* VCO rate control */
-#define RNG_CTL_VCO_SHIFT 6
-#define RNG_CTL_ASEL 0x0000000000000030ULL /* Analog MUX select */
-#define RNG_CTL_ASEL_SHIFT 4
+/* ver1 devices - n2-rng, vf-rng, kt-rng */
+#define RNG_v1_CTL_WAIT 0x0000000001fffe00ULL /* Minimum wait time */
+#define RNG_v1_CTL_WAIT_SHIFT 9
+#define RNG_v1_CTL_BYPASS 0x0000000000000100ULL /* VCO voltage source */
+#define RNG_v1_CTL_VCO 0x00000000000000c0ULL /* VCO rate control */
+#define RNG_v1_CTL_VCO_SHIFT 6
+#define RNG_v1_CTL_ASEL 0x0000000000000030ULL /* Analog MUX select */
+#define RNG_v1_CTL_ASEL_SHIFT 4
+#define RNG_v1_CTL_ASEL_NOOUT 2
+
+/* these are the same in v2 as in v1 */
#define RNG_CTL_LFSR 0x0000000000000008ULL /* Use LFSR or plain shift */
#define RNG_CTL_ES3 0x0000000000000004ULL /* Enable entropy source 3 */
#define RNG_CTL_ES2 0x0000000000000002ULL /* Enable entropy source 2 */
#define RNG_CTL_ES1 0x0000000000000001ULL /* Enable entropy source 1 */

+/* ver2 devices - m4-rng, m7-rng */
+#define RNG_v2_CTL_WAIT 0x0000000007fff800ULL /* Minimum wait time */
+#define RNG_v2_CTL_WAIT_SHIFT 12
+#define RNG_v2_CTL_BYPASS 0x0000000000000400ULL /* VCO voltage source */
+#define RNG_v2_CTL_VCO 0x0000000000000300ULL /* VCO rate control */
+#define RNG_v2_CTL_VCO_SHIFT 9
+#define RNG_v2_CTL_PERF 0x0000000000000180ULL /* Perf */
+#define RNG_v2_CTL_ASEL 0x0000000000000070ULL /* Analog MUX select */
+#define RNG_v2_CTL_ASEL_SHIFT 4
+#define RNG_v2_CTL_ASEL_NOOUT 7
+
+
#define HV_FAST_RNG_GET_DIAG_CTL 0x130
#define HV_FAST_RNG_CTL_READ 0x131
#define HV_FAST_RNG_CTL_WRITE 0x132
@@ -112,8 +128,10 @@ struct n2rng {

u64 scratch_control[HV_RNG_NUM_CONTROL];

-#define SELFTEST_TICKS 38859
-#define SELFTEST_VAL ((u64)0xB8820C7BD387E32C)
+#define RNG_v1_SELFTEST_TICKS 38859
+#define RNG_v1_SELFTEST_VAL ((u64)0xB8820C7BD387E32C)
+#define RNG_v2_SELFTEST_TICKS 64
+#define RNG_v2_SELFTEST_VAL ((u64)0xffffffffffffffff)
#define SELFTEST_POLY ((u64)0x231DCEE91262B8A3)
#define SELFTEST_MATCH_GOAL 6
#define SELFTEST_LOOPS_MAX 40000
--
1.7.1

Next message: Nicholas Mc Guire: "Re: [PATCH] Input: silead: use msleep() for long delays"
Previous message: Shannon Nelson: "[PATCH 4/4] n2rng: update version info"
In reply to: Shannon Nelson: "[PATCH 4/4] n2rng: update version info"
Next in thread: Herbert Xu: "Re: [PATCH 0/4] n2rng: add support for m5/m7 rng register layout"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]