// 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) 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(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