--- /dev/null
+/* drivers/misc/memory_state_time.c
+ *
+ * Copyright (C) 2016 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/hashtable.h>
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/memory-state-time.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/time.h>
+#include <linux/timekeeping.h>
+#include <linux/workqueue.h>
+
+#define KERNEL_ATTR_RO(_name) \
+static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+#define KERNEL_ATTR_RW(_name) \
+static struct kobj_attribute _name##_attr = \
+ __ATTR(_name, 0644, _name##_show, _name##_store)
+
+#define FREQ_HASH_BITS 4
+DECLARE_HASHTABLE(freq_hash_table, FREQ_HASH_BITS);
+
+static DEFINE_MUTEX(mem_lock);
+
+#define TAG "memory_state_time"
+#define BW_NODE "/soc/memory-state-time"
+#define FREQ_TBL "freq-tbl"
+#define BW_TBL "bw-buckets"
+#define NUM_SOURCES "num-sources"
+
+#define LOWEST_FREQ 2
+
+static int curr_bw;
+static int curr_freq;
+static u32 *bw_buckets;
+static u32 *freq_buckets;
+static int num_freqs;
+static int num_buckets;
+static int registered_bw_sources;
+static u64 last_update;
+static bool init_success;
+static struct workqueue_struct *memory_wq;
+static u32 num_sources = 10;
+static int *bandwidths;
+
+struct freq_entry {
+ int freq;
+ u64 *buckets; /* Bandwidth buckets. */
+ struct hlist_node hash;
+};
+
+struct queue_container {
+ struct work_struct update_state;
+ int value;
+ u64 time_now;
+ int id;
+ struct mutex *lock;
+};
+
+static int find_bucket(int bw)
+{
+ int i;
+
+ if (bw_buckets != NULL) {
+ for (i = 0; i < num_buckets; i++) {
+ if (bw_buckets[i] > bw) {
+ pr_debug("Found bucket %d for bandwidth %d\n",
+ i, bw);
+ return i;
+ }
+ }
+ return num_buckets - 1;
+ }
+ return 0;
+}
+
+static u64 get_time_diff(u64 time_now)
+{
+ u64 ms;
+
+ ms = time_now - last_update;
+ last_update = time_now;
+ return ms;
+}
+
+static ssize_t show_stat_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int i, j;
+ int len = 0;
+ struct freq_entry *freq_entry;
+
+ for (i = 0; i < num_freqs; i++) {
+ hash_for_each_possible(freq_hash_table, freq_entry, hash,
+ freq_buckets[i]) {
+ if (freq_entry->freq == freq_buckets[i]) {
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "%d ", freq_buckets[i]);
+ if (len >= PAGE_SIZE)
+ break;
+ for (j = 0; j < num_buckets; j++) {
+ len += scnprintf(buf + len,
+ PAGE_SIZE - len,
+ "%llu ",
+ freq_entry->buckets[j]);
+ }
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "\n");
+ }
+ }
+ }
+ pr_debug("Current Time: %llu\n", ktime_get_boot_ns());
+ return len;
+}
+KERNEL_ATTR_RO(show_stat);
+
+static void update_table(u64 time_now)
+{
+ struct freq_entry *freq_entry;
+
+ pr_debug("Last known bw %d freq %d\n", curr_bw, curr_freq);
+ hash_for_each_possible(freq_hash_table, freq_entry, hash, curr_freq) {
+ if (curr_freq == freq_entry->freq) {
+ freq_entry->buckets[find_bucket(curr_bw)]
+ += get_time_diff(time_now);
+ break;
+ }
+ }
+}
+
+static bool freq_exists(int freq)
+{
+ int i;
+
+ for (i = 0; i < num_freqs; i++) {
+ if (freq == freq_buckets[i])
+ return true;
+ }
+ return false;
+}
+
+static int calculate_total_bw(int bw, int index)
+{
+ int i;
+ int total_bw = 0;
+
+ pr_debug("memory_state_time New bw %d for id %d\n", bw, index);
+ bandwidths[index] = bw;
+ for (i = 0; i < registered_bw_sources; i++)
+ total_bw += bandwidths[i];
+ return total_bw;
+}
+
+static void freq_update_do_work(struct work_struct *work)
+{
+ struct queue_container *freq_state_update
+ = container_of(work, struct queue_container,
+ update_state);
+ if (freq_state_update) {
+ mutex_lock(&mem_lock);
+ update_table(freq_state_update->time_now);
+ curr_freq = freq_state_update->value;
+ mutex_unlock(&mem_lock);
+ kfree(freq_state_update);
+ }
+}
+
+static void bw_update_do_work(struct work_struct *work)
+{
+ struct queue_container *bw_state_update
+ = container_of(work, struct queue_container,
+ update_state);
+ if (bw_state_update) {
+ mutex_lock(&mem_lock);
+ update_table(bw_state_update->time_now);
+ curr_bw = calculate_total_bw(bw_state_update->value,
+ bw_state_update->id);
+ mutex_unlock(&mem_lock);
+ kfree(bw_state_update);
+ }
+}
+
+static void memory_state_freq_update(struct memory_state_update_block *ub,
+ int value)
+{
+ if (IS_ENABLED(CONFIG_MEMORY_STATE_TIME)) {
+ if (freq_exists(value) && init_success) {
+ struct queue_container *freq_container
+ = kmalloc(sizeof(struct queue_container),
+ GFP_KERNEL);
+ if (!freq_container)
+ return;
+ INIT_WORK(&freq_container->update_state,
+ freq_update_do_work);
+ freq_container->time_now = ktime_get_boot_ns();
+ freq_container->value = value;
+ pr_debug("Scheduling freq update in work queue\n");
+ queue_work(memory_wq, &freq_container->update_state);
+ } else {
+ pr_debug("Freq does not exist.\n");
+ }
+ }
+}
+
+static void memory_state_bw_update(struct memory_state_update_block *ub,
+ int value)
+{
+ if (IS_ENABLED(CONFIG_MEMORY_STATE_TIME)) {
+ if (init_success) {
+ struct queue_container *bw_container
+ = kmalloc(sizeof(struct queue_container),
+ GFP_KERNEL);
+ if (!bw_container)
+ return;
+ INIT_WORK(&bw_container->update_state,
+ bw_update_do_work);
+ bw_container->time_now = ktime_get_boot_ns();
+ bw_container->value = value;
+ bw_container->id = ub->id;
+ pr_debug("Scheduling bandwidth update in work queue\n");
+ queue_work(memory_wq, &bw_container->update_state);
+ }
+ }
+}
+
+struct memory_state_update_block *memory_state_register_frequency_source(void)
+{
+ struct memory_state_update_block *block;
+
+ if (IS_ENABLED(CONFIG_MEMORY_STATE_TIME)) {
+ pr_debug("Allocating frequency source\n");
+ block = kmalloc(sizeof(struct memory_state_update_block),
+ GFP_KERNEL);
+ if (!block)
+ return NULL;
+ block->update_call = memory_state_freq_update;
+ return block;
+ }
+ pr_err("Config option disabled.\n");
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(memory_state_register_frequency_source);
+
+struct memory_state_update_block *memory_state_register_bandwidth_source(void)
+{
+ struct memory_state_update_block *block;
+
+ if (IS_ENABLED(CONFIG_MEMORY_STATE_TIME)) {
+ pr_debug("Allocating bandwidth source %d\n",
+ registered_bw_sources);
+ block = kmalloc(sizeof(struct memory_state_update_block),
+ GFP_KERNEL);
+ if (!block)
+ return NULL;
+ block->update_call = memory_state_bw_update;
+ if (registered_bw_sources < num_sources) {
+ block->id = registered_bw_sources++;
+ } else {
+ pr_err("Unable to allocate source; max number reached\n");
+ kfree(block);
+ return NULL;
+ }
+ return block;
+ }
+ pr_err("Config option disabled.\n");
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(memory_state_register_bandwidth_source);
+
+/* Buckets are designated by their maximum.
+ * Returns the buckets decided by the capability of the device.
+ */
+static int get_bw_buckets(struct device *dev)
+{
+ int ret, lenb;
+ struct device_node *node = dev->of_node;
+
+ of_property_read_u32(node, NUM_SOURCES, &num_sources);
+ if (of_find_property(node, BW_TBL, &lenb)) {
+ bandwidths = devm_kzalloc(dev,
+ sizeof(*bandwidths) * num_sources, GFP_KERNEL);
+ if (!bandwidths)
+ return -ENOMEM;
+ lenb /= sizeof(*bw_buckets);
+ bw_buckets = devm_kzalloc(dev, lenb * sizeof(*bw_buckets),
+ GFP_KERNEL);
+ if (!bw_buckets) {
+ devm_kfree(dev, bandwidths);
+ return -ENOMEM;
+ }
+ ret = of_property_read_u32_array(node, BW_TBL, bw_buckets,
+ lenb);
+ if (ret < 0) {
+ devm_kfree(dev, bandwidths);
+ devm_kfree(dev, bw_buckets);
+ pr_err("Unable to read bandwidth table from device tree.\n");
+ return ret;
+ }
+ }
+ curr_bw = 0;
+ num_buckets = lenb;
+ return 0;
+}
+
+/* Adds struct freq_entry nodes to the hashtable for each compatible frequency.
+ * Returns the supported number of frequencies.
+ */
+static int freq_buckets_init(struct device *dev)
+{
+ struct freq_entry *freq_entry;
+ int i;
+ int ret, lenf;
+ struct device_node *node = dev->of_node;
+
+ if (of_find_property(node, FREQ_TBL, &lenf)) {
+ lenf /= sizeof(*freq_buckets);
+ freq_buckets = devm_kzalloc(dev, lenf * sizeof(*freq_buckets),
+ GFP_KERNEL);
+ if (!freq_buckets)
+ return -ENOMEM;
+ pr_debug("freqs found len %d\n", lenf);
+ ret = of_property_read_u32_array(node, FREQ_TBL, freq_buckets,
+ lenf);
+ if (ret < 0) {
+ devm_kfree(dev, freq_buckets);
+ pr_err("Unable to read frequency table from device tree.\n");
+ return ret;
+ }
+ pr_debug("ret freq %d\n", ret);
+ }
+ num_freqs = lenf;
+ curr_freq = freq_buckets[LOWEST_FREQ];
+
+ for (i = 0; i < num_freqs; i++) {
+ freq_entry = devm_kzalloc(dev, sizeof(struct freq_entry),
+ GFP_KERNEL);
+ if (!freq_entry)
+ return -ENOMEM;
+ freq_entry->buckets = devm_kzalloc(dev, sizeof(u64)*num_buckets,
+ GFP_KERNEL);
+ if (!freq_entry->buckets) {
+ devm_kfree(dev, freq_entry);
+ return -ENOMEM;
+ }
+ pr_debug("memory_state_time Adding freq to ht %d\n",
+ freq_buckets[i]);
+ freq_entry->freq = freq_buckets[i];
+ hash_add(freq_hash_table, &freq_entry->hash, freq_buckets[i]);
+ }
+ return 0;
+}
+
+struct kobject *memory_kobj;
+EXPORT_SYMBOL_GPL(memory_kobj);
+
+static struct attribute *memory_attrs[] = {
+ &show_stat_attr.attr,
+ NULL
+};
+
+static struct attribute_group memory_attr_group = {
+ .attrs = memory_attrs,
+};
+
+static int memory_state_time_probe(struct platform_device *pdev)
+{
+ int error;
+
+ error = get_bw_buckets(&pdev->dev);
+ if (error)
+ return error;
+ error = freq_buckets_init(&pdev->dev);
+ if (error)
+ return error;
+ last_update = ktime_get_boot_ns();
+ init_success = true;
+
+ pr_debug("memory_state_time initialized with num_freqs %d\n",
+ num_freqs);
+ return 0;
+}
+
+static const struct of_device_id match_table[] = {
+ { .compatible = "memory-state-time" },
+ {}
+};
+
+static struct platform_driver memory_state_time_driver = {
+ .probe = memory_state_time_probe,
+ .driver = {
+ .name = "memory-state-time",
+ .of_match_table = match_table,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init memory_state_time_init(void)
+{
+ int error;
+
+ hash_init(freq_hash_table);
+ memory_wq = create_singlethread_workqueue("memory_wq");
+ if (!memory_wq) {
+ pr_err("Unable to create workqueue.\n");
+ return -EINVAL;
+ }
+ /*
+ * Create sys/kernel directory for memory_state_time.
+ */
+ memory_kobj = kobject_create_and_add(TAG, kernel_kobj);
+ if (!memory_kobj) {
+ pr_err("Unable to allocate memory_kobj for sysfs directory.\n");
+ error = -ENOMEM;
+ goto wq;
+ }
+ error = sysfs_create_group(memory_kobj, &memory_attr_group);
+ if (error) {
+ pr_err("Unable to create sysfs folder.\n");
+ goto kobj;
+ }
+
+ error = platform_driver_register(&memory_state_time_driver);
+ if (error) {
+ pr_err("Unable to register memory_state_time platform driver.\n");
+ goto group;
+ }
+ return 0;
+
+group: sysfs_remove_group(memory_kobj, &memory_attr_group);
+kobj: kobject_put(memory_kobj);
+wq: destroy_workqueue(memory_wq);
+ return error;
+}
+module_init(memory_state_time_init);
projects / firefly-linux-kernel-4.4.55.git / commitdiff