mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 01:41:39 +00:00
![Rob Herring](/assets/img/avatar_default.png)
drivers/of/base.c is quite long and we've accumulated a number of CPU node functions. Let's move them to a new file, cpu.c, along with the lone of_cpu_device_node_get() in of_device.h. Moving the declaration has no effect yet as of.h is included by of_device.h. This serves as preparation to disentangle the includes in of_device.h and of_platform.h. Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-4-581e2605fe47@kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
210 lines
6.2 KiB
C
210 lines
6.2 KiB
C
// 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);
|