linux/drivers/base/arch_topology.c
Linus Torvalds f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00

244 lines
5.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Arch specific cpu topology information
*
* Copyright (C) 2016, ARM Ltd.
* Written by: Juri Lelli, ARM Ltd.
*/
#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sched/topology.h>
#include <linux/cpuset.h>
DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
unsigned long max_freq)
{
unsigned long scale;
int i;
scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
for_each_cpu(i, cpus)
per_cpu(freq_scale, i) = scale;
}
DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
{
per_cpu(cpu_scale, cpu) = capacity;
}
static ssize_t cpu_capacity_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, dev);
return sprintf(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
}
static void update_topology_flags_workfn(struct work_struct *work);
static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
static DEVICE_ATTR_RO(cpu_capacity);
static int register_cpu_capacity_sysctl(void)
{
int i;
struct device *cpu;
for_each_possible_cpu(i) {
cpu = get_cpu_device(i);
if (!cpu) {
pr_err("%s: too early to get CPU%d device!\n",
__func__, i);
continue;
}
device_create_file(cpu, &dev_attr_cpu_capacity);
}
return 0;
}
subsys_initcall(register_cpu_capacity_sysctl);
static int update_topology;
int topology_update_cpu_topology(void)
{
return update_topology;
}
/*
* Updating the sched_domains can't be done directly from cpufreq callbacks
* due to locking, so queue the work for later.
*/
static void update_topology_flags_workfn(struct work_struct *work)
{
update_topology = 1;
rebuild_sched_domains();
pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
update_topology = 0;
}
static u32 capacity_scale;
static u32 *raw_capacity;
static int free_raw_capacity(void)
{
kfree(raw_capacity);
raw_capacity = NULL;
return 0;
}
void topology_normalize_cpu_scale(void)
{
u64 capacity;
int cpu;
if (!raw_capacity)
return;
pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
for_each_possible_cpu(cpu) {
pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
cpu, raw_capacity[cpu]);
capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
/ capacity_scale;
topology_set_cpu_scale(cpu, capacity);
pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
cpu, topology_get_cpu_scale(cpu));
}
}
bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
{
static bool cap_parsing_failed;
int ret;
u32 cpu_capacity;
if (cap_parsing_failed)
return false;
ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
&cpu_capacity);
if (!ret) {
if (!raw_capacity) {
raw_capacity = kcalloc(num_possible_cpus(),
sizeof(*raw_capacity),
GFP_KERNEL);
if (!raw_capacity) {
cap_parsing_failed = true;
return false;
}
}
capacity_scale = max(cpu_capacity, capacity_scale);
raw_capacity[cpu] = cpu_capacity;
pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
cpu_node, raw_capacity[cpu]);
} else {
if (raw_capacity) {
pr_err("cpu_capacity: missing %pOF raw capacity\n",
cpu_node);
pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
}
cap_parsing_failed = true;
free_raw_capacity();
}
return !ret;
}
#ifdef CONFIG_CPU_FREQ
static cpumask_var_t cpus_to_visit;
static void parsing_done_workfn(struct work_struct *work);
static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
static int
init_cpu_capacity_callback(struct notifier_block *nb,
unsigned long val,
void *data)
{
struct cpufreq_policy *policy = data;
int cpu;
if (!raw_capacity)
return 0;
if (val != CPUFREQ_NOTIFY)
return 0;
pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
cpumask_pr_args(policy->related_cpus),
cpumask_pr_args(cpus_to_visit));
cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
for_each_cpu(cpu, policy->related_cpus) {
raw_capacity[cpu] = topology_get_cpu_scale(cpu) *
policy->cpuinfo.max_freq / 1000UL;
capacity_scale = max(raw_capacity[cpu], capacity_scale);
}
if (cpumask_empty(cpus_to_visit)) {
topology_normalize_cpu_scale();
schedule_work(&update_topology_flags_work);
free_raw_capacity();
pr_debug("cpu_capacity: parsing done\n");
schedule_work(&parsing_done_work);
}
return 0;
}
static struct notifier_block init_cpu_capacity_notifier = {
.notifier_call = init_cpu_capacity_callback,
};
static int __init register_cpufreq_notifier(void)
{
int ret;
/*
* on ACPI-based systems we need to use the default cpu capacity
* until we have the necessary code to parse the cpu capacity, so
* skip registering cpufreq notifier.
*/
if (!acpi_disabled || !raw_capacity)
return -EINVAL;
if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
return -ENOMEM;
cpumask_copy(cpus_to_visit, cpu_possible_mask);
ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
CPUFREQ_POLICY_NOTIFIER);
if (ret)
free_cpumask_var(cpus_to_visit);
return ret;
}
core_initcall(register_cpufreq_notifier);
static void parsing_done_workfn(struct work_struct *work)
{
cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
CPUFREQ_POLICY_NOTIFIER);
free_cpumask_var(cpus_to_visit);
}
#else
core_initcall(free_raw_capacity);
#endif