[ot] hw/opentitan: ot_ast_eg: implement the noise provider interface

Signed-off-by: Emmanuel Blot <[email protected]>

Author: rivos-eblot

hw/opentitan/Kconfig

@@ -23,6 +23,7 @@ config OT_AST_DJ
 config OT_AST_EG
     select IBEX_CLOCK_SRC
     select OT_CLOCK_CTRL
+    select OT_NOISE_SRC
     bool
 
 config OT_CLKMGR

hw/opentitan/ot_ast_eg.c

@@ -36,6 +36,7 @@
 #include "hw/opentitan/ot_ast_eg.h"
 #include "hw/opentitan/ot_clock_ctrl.h"
 #include "hw/opentitan/ot_common.h"
+#include "hw/opentitan/ot_noise_src.h"
 #include "hw/qdev-properties.h"
 #include "hw/registerfields.h"
 #include "hw/riscv/ibex_clock_src.h"
@@ -132,6 +133,8 @@ static const char REGB_NAMES[REGSB_COUNT][6U] = {
 };
 #undef REG_NAME_ENTRY
 
+#define OT_AST_EG_NOISE_4BIT_RATE 50000u /* 50 kHz */
+
 typedef struct {
     char *name;
     unsigned frequency;
@@ -161,16 +164,6 @@ struct OtASTEgClass {
     ResettablePhases parent_phases;
 };
 
-/* -------------------------------------------------------------------------- */
-/* Public API */
-/* -------------------------------------------------------------------------- */
-
-void ot_ast_eg_getrandom(void *buf, size_t len)
-{
-    qemu_guest_getrandom_nofail(buf, len);
-}
-
-
 static const char *CFGSEP = ",";
 
 static gint ot_ast_eg_match_clock_by_name(gconstpointer a, gconstpointer b)
@@ -260,6 +253,21 @@ static void ot_ast_eg_clock_ext_freq_select(OtClockCtrlIf *dev, bool enable)
     qemu_log_mask(LOG_UNIMP, "%s: not implemented: %u\n", __func__, enable);
 }
 
+static unsigned ot_ast_eg_get_fill_rate(OtNoiseSrcIf *dev)
+{
+    (void)dev;
+
+    return OT_AST_EG_NOISE_4BIT_RATE / 2u; /* 4 bits to byte */
+}
+
+static void ot_ast_eg_get_noise(OtNoiseSrcIf *dev, uint8_t *buffer,
+                                size_t length)
+{
+    (void)dev;
+
+    qemu_guest_getrandom_nofail((void *)buffer, length);
+}
+
 static void ot_ast_eg_parse_clocks(OtASTEgState *s, Error **errp)
 {
     if (!s->cfg_topclocks) {
@@ -580,6 +588,10 @@ static void ot_ast_eg_class_init(ObjectClass *klass, void *data)
     OtClockCtrlIfClass *cc = OT_CLOCK_CTRL_IF_CLASS(klass);
     cc->clock_enable = &ot_ast_eg_clock_enable;
     cc->clock_ext_freq_select = &ot_ast_eg_clock_ext_freq_select;
+
+    OtNoiseSrcIfClass *nc = OT_NOISE_SRC_IF_CLASS(klass);
+    nc->get_fill_rate = &ot_ast_eg_get_fill_rate;
+    nc->get_noise = &ot_ast_eg_get_noise;
 }
 
 static const TypeInfo ot_ast_eg_info = {
@@ -593,6 +605,7 @@ static const TypeInfo ot_ast_eg_info = {
         (InterfaceInfo[]){
             { TYPE_IBEX_CLOCK_SRC_IF },
             { TYPE_OT_CLOCK_CTRL_IF },
+            { TYPE_OT_NOISE_SRC_IF },
             {},
         },
 };

hw/riscv/ot_noise_src.c renamed to hw/opentitan/ot_noise_src.c

@@ -191,7 +191,7 @@ ot_entropy_src_io_write(const char *id, uint32_t addr, const char * regname, uin
 ot_entropy_src_no_entropy(const char *id, unsigned count) "%s: only %u words available"
 ot_entropy_src_obs_fifo(const char *id, unsigned level, unsigned thold) "%s: level %u, threshold %u"
 ot_entropy_src_push_bypass_entropy(const char *id, unsigned slot) "%s: final FIFO depth: %u"
-ot_entropy_src_reset(const char *id, void) "%s: "
+ot_entropy_src_reset(const char *id, const char *phase) "%s: %s"
 ot_entropy_src_show_buffer(const char *id, const char *func, int line, const char *msg, const char *hexstr) "%s: %s:%u %s: %s"
 ot_entropy_src_update_filler(const char *id, bool iok, bool ook, bool pok, bool all) "%s: in %u, out %u, proc %u -> %u"
 

hw/opentitan/trace-events

@@ -33,8 +33,4 @@
 #define TYPE_OT_AST_EG "ot-ast-eg"
 OBJECT_DECLARE_TYPE(OtASTEgState, OtASTEgClass, OT_AST_EG)
 
-#define OT_AST_EG_RANDOM_4BIT_RATE 50000u /* 50 kHz */
-
-void ot_ast_eg_getrandom(void *buf, size_t len);
-
 #endif /* HW_OPENTITAN_OT_AST_EG_H */