// SPDX-License-Identifier: GPL-2.0#include <linux/cpu.h>#include <linux/kernel.h>#include <linux/of.h> /** * of_get_cpu_hwid - Get the hardware ID from a CPU device node * * @cpun: CPU number(logical index) for which device node is required * @thread: The local thread number to get the hardware ID for. * * Return: The hardware ID for the CPU node or ~0ULL if not found. */u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread){	const __be32 *cell;	int ac, len; 	ac = of_n_addr_cells(cpun);	cell = of_get_property(cpun, "reg", &len);	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))		return ~0ULL; 	cell += ac * thread;	return of_read_number(cell, ac);} /* * arch_match_cpu_phys_id - Match the given logical CPU and physical id * * @cpu: logical cpu index of a core/thread * @phys_id: physical identifier of a core/thread * * CPU logical to physical index mapping is architecture specific. * However this __weak function provides a default match of physical * id to logical cpu index. phys_id provided here is usually values read * from the device tree which must match the hardware internal registers. * * Returns true if the physical identifier and the logical cpu index * correspond to the same core/thread, false otherwise. */bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id){	return (u32)phys_id == cpu;} /* * Checks if the given "prop_name" property holds the physical id of the * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not * NULL, local thread number within the core is returned in it. */static bool __of_find_n_match_cpu_property(struct device_node *cpun,			const char *prop_name, int cpu, unsigned int *thread){	const __be32 *cell;	int ac, prop_len, tid;	u64 hwid; 	ac = of_n_addr_cells(cpun);	cell = of_get_property(cpun, prop_name, &prop_len);	if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))		return true;	if (!cell || !ac || ac > 2)		return false;	prop_len /= sizeof(*cell) * ac;	for (tid = 0; tid < prop_len; tid++) {		hwid = of_read_number(cell, ac);		if (arch_match_cpu_phys_id(cpu, hwid)) {			if (thread)				*thread = tid;			return true;		}		cell += ac;	}	return false;} /* * arch_find_n_match_cpu_physical_id - See if the given device node is * for the cpu corresponding to logical cpu 'cpu'.  Return true if so, * else false.  If 'thread' is non-NULL, the local thread number within the * core is returned in it. */bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,					      int cpu, unsigned int *thread){	/* Check for non-standard "ibm,ppc-interrupt-server#s" property	 * for thread ids on PowerPC. If it doesn't exist fallback to	 * standard "reg" property.	 */	if (IS_ENABLED(CONFIG_PPC) &&	    __of_find_n_match_cpu_property(cpun,					   "ibm,ppc-interrupt-server#s",					   cpu, thread))		return true; 	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);} /** * of_get_cpu_node - Get device node associated with the given logical CPU * * @cpu: CPU number(logical index) for which device node is required * @thread: if not NULL, local thread number within the physical core is *          returned * * The main purpose of this function is to retrieve the device node for the * given logical CPU index. It should be used to initialize the of_node in * cpu device. Once of_node in cpu device is populated, all the further * references can use that instead. * * CPU logical to physical index mapping is architecture specific and is built * before booting secondary cores. This function uses arch_match_cpu_phys_id * which can be overridden by architecture specific implementation. * * Return: A node pointer for the logical cpu with refcount incremented, use * of_node_put() on it when done. Returns NULL if not found. */struct device_node *of_get_cpu_node(int cpu, unsigned int *thread){	struct device_node *cpun; 	for_each_of_cpu_node(cpun) {		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))			return cpun;	}	return NULL;}EXPORT_SYMBOL(of_get_cpu_node); /** * of_cpu_device_node_get: Get the CPU device_node for a given logical CPU number * * @cpu: The logical CPU number * * Return: Pointer to the device_node for CPU with its reference count * incremented of the given logical CPU number or NULL if the CPU device_node * is not found. */struct device_node *of_cpu_device_node_get(int cpu){	struct device *cpu_dev;	cpu_dev = get_cpu_device(cpu);	if (!cpu_dev)		return of_get_cpu_node(cpu, NULL);	return of_node_get(cpu_dev->of_node);}EXPORT_SYMBOL(of_cpu_device_node_get); /** * of_cpu_node_to_id: Get the logical CPU number for a given device_node * * @cpu_node: Pointer to the device_node for CPU. * * Return: The logical CPU number of the given CPU device_node or -ENODEV if the * CPU is not found. */int of_cpu_node_to_id(struct device_node *cpu_node){	int cpu;	bool found = false;	struct device_node *np; 	for_each_possible_cpu(cpu) {		np = of_cpu_device_node_get(cpu);		found = (cpu_node == np);		of_node_put(np);		if (found)			return cpu;	} 	return -ENODEV;}EXPORT_SYMBOL(of_cpu_node_to_id); /** * of_get_cpu_state_node - Get CPU's idle state node at the given index * * @cpu_node: The device node for the CPU * @index: The index in the list of the idle states * * Two generic methods can be used to describe a CPU's idle states, either via * a flattened description through the "cpu-idle-states" binding or via the * hierarchical layout, using the "power-domains" and the "domain-idle-states" * bindings. This function check for both and returns the idle state node for * the requested index. * * Return: An idle state node if found at @index. The refcount is incremented * for it, so call of_node_put() on it when done. Returns NULL if not found. */struct device_node *of_get_cpu_state_node(const struct device_node *cpu_node,					  int index){	struct of_phandle_args args;	int err; 	err = of_parse_phandle_with_args(cpu_node, "power-domains",					"#power-domain-cells", 0, &args);	if (!err) {		struct device_node *state_node =			of_parse_phandle(args.np, "domain-idle-states", index); 		of_node_put(args.np);		if (state_node)			return state_node;	} 	return of_parse_phandle(cpu_node, "cpu-idle-states", index);}EXPORT_SYMBOL(of_get_cpu_state_node);