// 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(of_get_cpu_state_node);
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