Currently the cq counters are allocated in userspace memory,
and mapped by the driver to the device address space.
A new requirement that is part of new future API related to this one,
requires that cq counters will be allocated in kernel memory.
We leverage the existing cb_create API with KERNEL_MAPPED flag set to
allocate this memory.
That way we gain two things:
1. The memory cannot be freed while in use since it's protected
by refcount in driver.
2. No need to wake up the user thread upon each interrupt from CQ,
because the kernel has direct access to the counter. Therefore,
it can make comparison with the target value in the interrupt
handler and wake up the user thread only if the counter reaches the
target value. This is instead of waking the thread up to copy counter
value from user then go sleep again if target value wasn't reached.
Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
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