/**
* See if a device structure already exists and if not allocate it.
*
* @param parent The bus to find the device on.
* @param path The relative path from the bus to the appropriate device.
* @return Pointer to a device structure for the device on bus at path.
*/
device_t alloc_find_dev(struct bus *parent, struct device_path *path)
{
device_t child;
spin_lock(&dev_lock);
child = find_dev_path(parent, path);
if (!child)
child = __alloc_dev(parent, path);
spin_unlock(&dev_lock);
return child;
}
device_t add_cpu_device(struct bus *cpu_bus, unsigned apic_id, int enabled)
{
struct device_path cpu_path;
device_t cpu;
/* Build the cpu device path */
cpu_path.type = DEVICE_PATH_APIC;
cpu_path.apic.apic_id = apic_id;
/* Update CPU in devicetree. */
if (enabled)
cpu = alloc_find_dev(cpu_bus, &cpu_path);
else
cpu = find_dev_path(cpu_bus, &cpu_path);
if (!cpu)
return NULL;
cpu->enabled = enabled;
printk(BIOS_DEBUG, "CPU: %s %s\n",
dev_path(cpu), cpu->enabled?"enabled":"disabled");
return cpu;
}