Multi NPU update APIs
Modifying mutex and semaphore APIs allowing the driver to create
any number of mutexes and semaphores.
Using semaphore when waiting for interrupt.
Making irq_triggered a member of the driver struct.
Change-Id: Ib0645c9c7c0c029795269ac4b18e6ec29159d0f8
diff --git a/include/ethosu_driver.h b/include/ethosu_driver.h
index 2ce59c2..16f0a25 100644
--- a/include/ethosu_driver.h
+++ b/include/ethosu_driver.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2019-2020 Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2021 Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
@@ -47,6 +47,8 @@
bool dev_power_always_on;
struct ethosu_driver *next;
bool reserved;
+ volatile bool irq_triggered;
+ void *semaphore;
};
struct ethosu_version_id
diff --git a/src/ethosu_driver.c b/src/ethosu_driver.c
index d4c4307..442ea43 100644
--- a/src/ethosu_driver.c
+++ b/src/ethosu_driver.c
@@ -157,50 +157,57 @@
// Registered drivers linked list HEAD
static struct ethosu_driver *registered_drivers = NULL;
-// IRQ
-static volatile bool irq_triggered = false;
+/*
+ * Following section handles the minimal sempahore and mutex implementation in case of baremetal applications.
+ * Weak symbols will be overwritten by RTOS definitions and implement true thread-safety. (Done in application layer)
+ */
+
+// Baremetal sempahore implementation
+struct ethosu_semaphore_t
+{
+ int count;
+};
+
+// Minimal needed declaration to allow baremetal functionality.
+static void *ethosu_mutex;
+static void *ethosu_semaphore;
+
+void *__attribute__((weak)) ethosu_mutex_create(void) {}
+
+void __attribute__((weak)) ethosu_mutex_lock(void *mutex) {}
+
+void __attribute__((weak)) ethosu_mutex_unlock(void *mutex) {}
+
+// Baremetal implementation of creating a semaphore
+void *__attribute__((weak)) ethosu_semaphore_create(void)
+{
+ struct ethosu_semaphore_t *sem = malloc(sizeof(*sem));
+ sem->count = 1;
+ return sem;
+}
+
+// Baremetal simulation of waiting/sleeping for and then taking a semaphore using intrisics
+void __attribute__((weak)) ethosu_semaphore_take(void *sem)
+{
+ struct ethosu_semaphore_t *s = sem;
+ while (s->count <= 0)
+ {
+ __WFE();
+ }
+ s->count--;
+}
+
+// Baremetal simulation of giving a semaphore and waking up processes using intrinsics
+void __attribute__((weak)) ethosu_semaphore_give(void *sem)
+{
+ struct ethosu_semaphore_t *s = sem;
+ s->count++;
+ __SEV();
+}
+// <--- End of semaphore and mutex implementations
+
static int ethosu_soft_reset_and_restore(struct ethosu_driver *drv);
-/* Default implementation to initialise ethosu driver mutex. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_mutex_init() {}
-
-/* Default implementation to initialise ethosu driver binary semaphore. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_semaphore_init() {}
-
-/* Default implementation to lock ethosu driver mutex. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_mutex_lock() {}
-
-/* Default implementation to unlock ethosu driver mutex. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_mutex_unlock() {}
-
-/* Default implementation to wait for and take free ethosu driver semaphore. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_semaphore_take() {}
-
-/* Default implementation to give ethosu driver semaphore. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_semaphore_give() {}
-
-/* Default implementation to force context-switch while waiting for Ethos-U IRQ. Override if available on the targeted
- * RTOS. If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_yield() {}
-
-/* Default implementation to indicate thread/task is resuming. Override if available on the targeted RTOS.
- * If not overridden, will do nothing (assumes baremetal).
- */
-void __attribute__((weak)) ethosu_resume() {}
-
void __attribute__((weak)) ethosu_irq_handler_v2(struct ethosu_driver *drv)
{
uint8_t irq_raised = 0;
@@ -212,7 +219,7 @@
// Verify that interrupt has been raised
(void)ethosu_is_irq_raised(&drv->dev, &irq_raised);
ASSERT(irq_raised == 1);
- irq_triggered = true;
+ drv->irq_triggered = true;
// Clear interrupt
(void)ethosu_clear_irq_status(&drv->dev);
@@ -226,24 +233,21 @@
ethosu_soft_reset_and_restore(drv);
drv->status_error = true;
}
+
+ ethosu_semaphore_give(drv->semaphore);
}
static inline void wait_for_irq(struct ethosu_driver *drv)
{
while (1)
{
- __disable_irq();
- if (irq_triggered || drv->abort_inference)
+ if (drv->irq_triggered || drv->abort_inference)
{
- __enable_irq();
+ drv->irq_triggered = false;
break;
}
- __WFI();
-
- ethosu_yield();
- __enable_irq();
- ethosu_resume();
+ ethosu_semaphore_take(drv->semaphore);
}
}
@@ -278,12 +282,22 @@
secure_enable,
privilege_enable);
- ethosu_mutex_init();
- ethosu_semaphore_init();
+ if (!ethosu_mutex)
+ {
+ ethosu_mutex = ethosu_mutex_create();
+ }
+
+ if (!ethosu_semaphore)
+ {
+ ethosu_semaphore = ethosu_semaphore_create();
+ }
+
ethosu_register_driver(drv);
drv->fast_memory = (uint32_t)fast_memory;
drv->fast_memory_size = fast_memory_size;
+ drv->irq_triggered = false;
+ drv->semaphore = ethosu_semaphore_create();
if (ETHOSU_SUCCESS != ethosu_dev_init(&drv->dev, base_address, secure_enable, privilege_enable))
{
@@ -429,7 +443,7 @@
drv->abort_inference = false;
// It is safe to clear this flag without atomic, because npu is not running.
- irq_triggered = false;
+ drv->irq_triggered = false;
ret = handle_command_stream(drv, command_stream, cms_length, base_addr, base_addr_size, num_base_addr);
@@ -549,16 +563,17 @@
do
{
- ethosu_mutex_lock();
+ ethosu_mutex_lock(ethosu_mutex);
drv = ethosu_find_and_reserve_driver();
- ethosu_mutex_unlock();
+ ethosu_mutex_unlock(ethosu_mutex);
if (drv != NULL)
{
break;
}
- ethosu_semaphore_take();
+ LOG_INFO("%s - Waiting for driver \n", __FUNCTION__);
+ ethosu_semaphore_take(ethosu_semaphore);
} while (1);
@@ -587,14 +602,14 @@
void ethosu_release_driver(struct ethosu_driver *drv)
{
- ethosu_mutex_lock();
+ ethosu_mutex_lock(ethosu_mutex);
if (drv != NULL && drv->reserved)
{
drv->reserved = false;
LOG_INFO("%s - Driver %p released\n", __FUNCTION__, drv);
- ethosu_semaphore_give();
+ ethosu_semaphore_give(ethosu_semaphore);
}
- ethosu_mutex_unlock();
+ ethosu_mutex_unlock(ethosu_mutex);
}
static int ethosu_soft_reset_and_restore(struct ethosu_driver *drv)