Sorry if this post appears twice, my first attempt seems to have failed.
I need to write that piece of code that is generic enough that it allows giving a semaphore from the context of either an ISR or a task. Since an ISR must use xSemaphoreGiveFromISR to give semaphores, is it possible to use xSemaphoreGiveFromISR in the context of a task?
You can use xQueueGenericSendFromISR() from a task but need to take care of critical sections. The ISR version uses portSET_INTERRUPT_MASK_FROM_ISR() which is only defined for ports that use interrupt nesting. You would need to implement an equivalent for your port if it were not already defined.