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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-03 20:27:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-03 20:27:48 -0700
commit974668417b74ec5f68df2411f53b3d3812565059 (patch)
treec76be88bc72bf6b0abe8843f418e4e2518053947 /drivers/base/arch_topology.c
parent9a715cd54347948e74f1a597da22884af287727d (diff)
parentd565ed38d045793b76f022565a50793a3535bdbd (diff)
downloadop-kernel-dev-974668417b74ec5f68df2411f53b3d3812565059.zip
op-kernel-dev-974668417b74ec5f68df2411f53b3d3812565059.tar.gz
Merge tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH: "Here is the big driver core update for 4.13-rc1. The large majority of this is a lot of cleanup of old fields in the driver core structures and their remaining usages in random drivers. All of those fixes have been reviewed by the various subsystem maintainers. There's also some small firmware updates in here, a new kobject uevent api interface that makes userspace interaction easier, and a few other minor things. All of these have been in linux-next for a long while with no reported issues" * tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (56 commits) arm: mach-rpc: ecard: fix build error zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO() driver-core: remove struct bus_type.dev_attrs powerpc: vio_cmo: use dev_groups and not dev_attrs for bus_type powerpc: vio: use dev_groups and not dev_attrs for bus_type USB: usbip: convert to use DRIVER_ATTR_RW s390: drivers: convert to use DRIVER_ATTR_RO/WO platform: thinkpad_acpi: convert to use DRIVER_ATTR_RO/RW pcmcia: ds: convert to use DRIVER_ATTR_RO wireless: ipw2x00: convert to use DRIVER_ATTR_RW net: ehea: convert to use DRIVER_ATTR_RO net: caif: convert to use DRIVER_ATTR_RO TTY: hvc: convert to use DRIVER_ATTR_RW PCI: pci-driver: convert to use DRIVER_ATTR_WO IB: nes: convert to use DRIVER_ATTR_RW HID: hid-core: convert to use DRIVER_ATTR_RO and drv_groups arm: ecard: fix dev_groups patch typo tty: serdev: use dev_groups and not dev_attrs for bus_type sparc: vio: use dev_groups and not dev_attrs for bus_type hid: intel-ish-hid: use dev_groups and not dev_attrs for bus_type ...
Diffstat (limited to 'drivers/base/arch_topology.c')
-rw-r--r--drivers/base/arch_topology.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
new file mode 100644
index 0000000..d1c33a8
--- /dev/null
+++ b/drivers/base/arch_topology.c
@@ -0,0 +1,243 @@
+/*
+ * Arch specific cpu topology information
+ *
+ * Copyright (C) 2016, ARM Ltd.
+ * Written by: Juri Lelli, ARM Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/acpi.h>
+#include <linux/arch_topology.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>
+
+static DEFINE_MUTEX(cpu_scale_mutex);
+static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
+
+unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu)
+{
+ return per_cpu(cpu_scale, cpu);
+}
+
+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(NULL, cpu->dev.id));
+}
+
+static ssize_t cpu_capacity_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct cpu *cpu = container_of(dev, struct cpu, dev);
+ int this_cpu = cpu->dev.id;
+ int i;
+ unsigned long new_capacity;
+ ssize_t ret;
+
+ if (!count)
+ return 0;
+
+ ret = kstrtoul(buf, 0, &new_capacity);
+ if (ret)
+ return ret;
+ if (new_capacity > SCHED_CAPACITY_SCALE)
+ return -EINVAL;
+
+ mutex_lock(&cpu_scale_mutex);
+ for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
+ topology_set_cpu_scale(i, new_capacity);
+ mutex_unlock(&cpu_scale_mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(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 u32 capacity_scale;
+static u32 *raw_capacity;
+static bool cap_parsing_failed;
+
+void topology_normalize_cpu_scale(void)
+{
+ u64 capacity;
+ int cpu;
+
+ if (!raw_capacity || cap_parsing_failed)
+ return;
+
+ pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
+ mutex_lock(&cpu_scale_mutex);
+ 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(NULL, cpu));
+ }
+ mutex_unlock(&cpu_scale_mutex);
+}
+
+int __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
+{
+ int ret = 1;
+ u32 cpu_capacity;
+
+ if (cap_parsing_failed)
+ return !ret;
+
+ 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) {
+ pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
+ cap_parsing_failed = true;
+ return 0;
+ }
+ }
+ capacity_scale = max(cpu_capacity, capacity_scale);
+ raw_capacity[cpu] = cpu_capacity;
+ pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
+ cpu_node->full_name, raw_capacity[cpu]);
+ } else {
+ if (raw_capacity) {
+ pr_err("cpu_capacity: missing %s raw capacity\n",
+ cpu_node->full_name);
+ pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
+ }
+ cap_parsing_failed = true;
+ kfree(raw_capacity);
+ }
+
+ return !ret;
+}
+
+#ifdef CONFIG_CPU_FREQ
+static cpumask_var_t cpus_to_visit;
+static bool cap_parsing_done;
+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 (cap_parsing_failed || cap_parsing_done)
+ return 0;
+
+ switch (val) {
+ case CPUFREQ_NOTIFY:
+ 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(NULL, cpu) *
+ policy->cpuinfo.max_freq / 1000UL;
+ capacity_scale = max(raw_capacity[cpu], capacity_scale);
+ }
+ if (cpumask_empty(cpus_to_visit)) {
+ topology_normalize_cpu_scale();
+ kfree(raw_capacity);
+ pr_debug("cpu_capacity: parsing done\n");
+ cap_parsing_done = true;
+ 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)
+{
+ /*
+ * 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)) {
+ pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpus_to_visit, cpu_possible_mask);
+
+ return cpufreq_register_notifier(&init_cpu_capacity_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+}
+core_initcall(register_cpufreq_notifier);
+
+static void parsing_done_workfn(struct work_struct *work)
+{
+ cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+}
+
+#else
+static int __init free_raw_capacity(void)
+{
+ kfree(raw_capacity);
+
+ return 0;
+}
+core_initcall(free_raw_capacity);
+#endif
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