static int ne_get_cpu_from_cpu_pool()

in drivers/virt/nitro_enclaves/ne_misc_dev.c [657:697]

• 23 lines of code
• 4 McCabe index (conditional complexity)

static int ne_get_cpu_from_cpu_pool(struct ne_enclave *ne_enclave, u32 *vcpu_id)
{
	int core_id = -1;
	unsigned int cpu = 0;
	unsigned int i = 0;
	int rc = -EINVAL;

	/*
	 * If previously allocated a thread of a core to this enclave, first
	 * check remaining sibling(s) for new CPU allocations, so that full
	 * CPU cores are used for the enclave.
	 */
	for (i = 0; i < ne_enclave->nr_parent_vm_cores; i++)
		for_each_cpu(cpu, ne_enclave->threads_per_core[i])
			if (!ne_donated_cpu(ne_enclave, cpu)) {
				*vcpu_id = cpu;

				return 0;
			}

	mutex_lock(&ne_cpu_pool.mutex);

	/*
	 * If no remaining siblings, get a core from the NE CPU pool and keep
	 * track of all the threads in the enclave threads per core data structure.
	 */
	core_id = ne_get_unused_core_from_cpu_pool();

	rc = ne_set_enclave_threads_per_core(ne_enclave, core_id, *vcpu_id);
	if (rc < 0)
		goto unlock_mutex;

	*vcpu_id = cpumask_any(ne_enclave->threads_per_core[core_id]);

	rc = 0;

unlock_mutex:
	mutex_unlock(&ne_cpu_pool.mutex);

	return rc;
}