MLBEDSW-2594 Initialize the Ethos-U before every job

This includes resetting the Ethos-U and restoring the
previosuly saved PMU configuration (if any).

Change-Id: Id952fb6fef513468952b6a469e857510f8c0214c

2 files changed, 47 insertions, 1 deletions

diff --git a/src/ethosu_device.c b/src/ethosu_device.c
index 9bda87d..60fc243 100644
--- a/src/ethosu_device.c
+++ b/src/ethosu_device.c
@@ -551,3 +551,42 @@ void ethosu_write_reg(struct ethosu_device *dev, uint32_t address, uint32_t valu
     UNUSED(value);
 #endif
 }
+
+enum ethosu_error_codes ethosu_save_pmu_config(struct ethosu_device *dev)
+{
+#if !defined(ARM_NPU_STUB)
+    dev->pmccntr = ETHOSU_PMU_Get_CCNTR();
+    for (uint32_t i = 0; i < ETHOSU_PMU_NCOUNTERS; i++)
+    {
+        dev->pmu_evcntr[i] = ETHOSU_PMU_Get_EVCNTR(i);
+        dev->pmu_evtypr[i] = ETHOSU_PMU_Get_EVTYPER(i);
+    }
+    if (!dev->restore_pmu_config)
+    {
+        dev->restore_pmu_config = true;
+    }
+#else
+    UNUSED(dev);
+#endif
+
+    return ETHOSU_SUCCESS;
+}
+
+enum ethosu_error_codes ethosu_restore_pmu_config(struct ethosu_device *dev)
+{
+#if !defined(ARM_NPU_STUB)
+    if (dev->restore_pmu_config)
+    {
+        ETHOSU_PMU_Set_CCNTR(dev->pmccntr);
+        for (uint32_t i = 0; i < ETHOSU_PMU_NCOUNTERS; i++)
+        {
+            ETHOSU_PMU_Set_EVCNTR(i, dev->pmu_evcntr[i]);
+            ETHOSU_PMU_Set_EVTYPER(i, dev->pmu_evtypr[i]);
+        }
+    }
+#else
+    UNUSED(dev);
+#endif
+
+    return ETHOSU_SUCCESS;
+}
diff --git a/src/ethosu_driver.c b/src/ethosu_driver.c
index 1a9337e..9d74980 100644
--- a/src/ethosu_driver.c
+++ b/src/ethosu_driver.c
@@ -29,7 +29,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-struct ethosu_driver ethosu_drv = {.dev = {.base_address = NULL}, .abort_inference = false};
+struct ethosu_driver ethosu_drv = {.dev             = {.base_address       = NULL,
+                                           .restore_pmu_config = false,
+                                           .pmccntr            = 0,
+                                           .pmu_evcntr         = {0, 0, 0, 0},
+                                           .pmu_evtypr         = {0, 0, 0, 0}},
+                                   .abort_inference = false};
 
 // IRQ
 static volatile bool irq_triggered = false;
@@ -276,6 +281,7 @@ int ethosu_invoke(const void *custom_data_ptr,
     int custom_data_32bit_size = (custom_data_size / BYTES_IN_32_BITS - CUSTOM_OPTION_LENGTH_32_BIT_WORD);
 
     ethosu_set_clock_and_power(&ethosu_drv.dev, ETHOSU_CLOCK_Q_ENABLE, ETHOSU_POWER_Q_DISABLE);
+    ethosu_restore_pmu_config(&ethosu_drv.dev);
     while (data_ptr < (data_start_ptr + custom_data_32bit_size))
     {
         int ret = 0;
@@ -337,6 +343,7 @@ int ethosu_invoke(const void *custom_data_ptr,
             break;
         }
     }
+    ethosu_save_pmu_config(&ethosu_drv.dev);
     ethosu_set_clock_and_power(&ethosu_drv.dev, ETHOSU_CLOCK_Q_ENABLE, ETHOSU_POWER_Q_ENABLE);
     return return_code;
 }