From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- drivers/cpufreq/cpufreq_stats.c | 289 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 drivers/cpufreq/cpufreq_stats.c (limited to 'drivers/cpufreq/cpufreq_stats.c') diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c new file mode 100644 index 000000000..670a10c3e --- /dev/null +++ b/drivers/cpufreq/cpufreq_stats.c @@ -0,0 +1,289 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/cpufreq/cpufreq_stats.c + * + * Copyright (C) 2003-2004 Venkatesh Pallipadi . + * (C) 2004 Zou Nan hai . + */ + +#include +#include +#include +#include +#include + +struct cpufreq_stats { + unsigned int total_trans; + unsigned long long last_time; + unsigned int max_state; + unsigned int state_num; + unsigned int last_index; + u64 *time_in_state; + unsigned int *freq_table; + unsigned int *trans_table; + + /* Deferred reset */ + unsigned int reset_pending; + unsigned long long reset_time; +}; + +static void cpufreq_stats_update(struct cpufreq_stats *stats, + unsigned long long time) +{ + unsigned long long cur_time = local_clock(); + + stats->time_in_state[stats->last_index] += cur_time - time; + stats->last_time = cur_time; +} + +static void cpufreq_stats_reset_table(struct cpufreq_stats *stats) +{ + unsigned int count = stats->max_state; + + memset(stats->time_in_state, 0, count * sizeof(u64)); + memset(stats->trans_table, 0, count * count * sizeof(int)); + stats->last_time = local_clock(); + stats->total_trans = 0; + + /* Adjust for the time elapsed since reset was requested */ + WRITE_ONCE(stats->reset_pending, 0); + /* + * Prevent the reset_time read from being reordered before the + * reset_pending accesses in cpufreq_stats_record_transition(). + */ + smp_rmb(); + cpufreq_stats_update(stats, READ_ONCE(stats->reset_time)); +} + +static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) +{ + struct cpufreq_stats *stats = policy->stats; + + if (READ_ONCE(stats->reset_pending)) + return sprintf(buf, "%d\n", 0); + else + return sprintf(buf, "%u\n", stats->total_trans); +} +cpufreq_freq_attr_ro(total_trans); + +static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) +{ + struct cpufreq_stats *stats = policy->stats; + bool pending = READ_ONCE(stats->reset_pending); + unsigned long long time; + ssize_t len = 0; + int i; + + for (i = 0; i < stats->state_num; i++) { + if (pending) { + if (i == stats->last_index) { + /* + * Prevent the reset_time read from occurring + * before the reset_pending read above. + */ + smp_rmb(); + time = local_clock() - READ_ONCE(stats->reset_time); + } else { + time = 0; + } + } else { + time = stats->time_in_state[i]; + if (i == stats->last_index) + time += local_clock() - stats->last_time; + } + + len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], + nsec_to_clock_t(time)); + } + return len; +} +cpufreq_freq_attr_ro(time_in_state); + +/* We don't care what is written to the attribute */ +static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, + size_t count) +{ + struct cpufreq_stats *stats = policy->stats; + + /* + * Defer resetting of stats to cpufreq_stats_record_transition() to + * avoid races. + */ + WRITE_ONCE(stats->reset_time, local_clock()); + /* + * The memory barrier below is to prevent the readers of reset_time from + * seeing a stale or partially updated value. + */ + smp_wmb(); + WRITE_ONCE(stats->reset_pending, 1); + + return count; +} +cpufreq_freq_attr_wo(reset); + +static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) +{ + struct cpufreq_stats *stats = policy->stats; + bool pending = READ_ONCE(stats->reset_pending); + ssize_t len = 0; + int i, j, count; + + len += sysfs_emit_at(buf, len, " From : To\n"); + len += sysfs_emit_at(buf, len, " : "); + for (i = 0; i < stats->state_num; i++) { + if (len >= PAGE_SIZE - 1) + break; + len += sysfs_emit_at(buf, len, "%9u ", stats->freq_table[i]); + } + if (len >= PAGE_SIZE - 1) + return PAGE_SIZE - 1; + + len += sysfs_emit_at(buf, len, "\n"); + + for (i = 0; i < stats->state_num; i++) { + if (len >= PAGE_SIZE - 1) + break; + + len += sysfs_emit_at(buf, len, "%9u: ", stats->freq_table[i]); + + for (j = 0; j < stats->state_num; j++) { + if (len >= PAGE_SIZE - 1) + break; + + if (pending) + count = 0; + else + count = stats->trans_table[i * stats->max_state + j]; + + len += sysfs_emit_at(buf, len, "%9u ", count); + } + if (len >= PAGE_SIZE - 1) + break; + len += sysfs_emit_at(buf, len, "\n"); + } + + if (len >= PAGE_SIZE - 1) { + pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n"); + return -EFBIG; + } + return len; +} +cpufreq_freq_attr_ro(trans_table); + +static struct attribute *default_attrs[] = { + &total_trans.attr, + &time_in_state.attr, + &reset.attr, + &trans_table.attr, + NULL +}; +static const struct attribute_group stats_attr_group = { + .attrs = default_attrs, + .name = "stats" +}; + +static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq) +{ + int index; + for (index = 0; index < stats->max_state; index++) + if (stats->freq_table[index] == freq) + return index; + return -1; +} + +void cpufreq_stats_free_table(struct cpufreq_policy *policy) +{ + struct cpufreq_stats *stats = policy->stats; + + /* Already freed */ + if (!stats) + return; + + pr_debug("%s: Free stats table\n", __func__); + + sysfs_remove_group(&policy->kobj, &stats_attr_group); + kfree(stats->time_in_state); + kfree(stats); + policy->stats = NULL; +} + +void cpufreq_stats_create_table(struct cpufreq_policy *policy) +{ + unsigned int i = 0, count; + struct cpufreq_stats *stats; + unsigned int alloc_size; + struct cpufreq_frequency_table *pos; + + count = cpufreq_table_count_valid_entries(policy); + if (!count) + return; + + /* stats already initialized */ + if (policy->stats) + return; + + stats = kzalloc_obj(*stats); + if (!stats) + return; + + alloc_size = count * sizeof(int) + count * sizeof(u64); + + alloc_size += count * count * sizeof(int); + + /* Allocate memory for time_in_state/freq_table/trans_table in one go */ + stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL); + if (!stats->time_in_state) + goto free_stat; + + stats->freq_table = (unsigned int *)(stats->time_in_state + count); + + stats->trans_table = stats->freq_table + count; + + stats->max_state = count; + + /* Find valid-unique entries */ + cpufreq_for_each_valid_entry(pos, policy->freq_table) + if (policy->freq_table_sorted != CPUFREQ_TABLE_UNSORTED || + freq_table_get_index(stats, pos->frequency) == -1) + stats->freq_table[i++] = pos->frequency; + + stats->state_num = i; + stats->last_time = local_clock(); + stats->last_index = freq_table_get_index(stats, policy->cur); + + policy->stats = stats; + if (!sysfs_create_group(&policy->kobj, &stats_attr_group)) + return; + + /* We failed, release resources */ + policy->stats = NULL; + kfree(stats->time_in_state); +free_stat: + kfree(stats); +} + +void cpufreq_stats_record_transition(struct cpufreq_policy *policy, + unsigned int new_freq) +{ + struct cpufreq_stats *stats = policy->stats; + int old_index, new_index; + + if (unlikely(!stats)) + return; + + if (unlikely(READ_ONCE(stats->reset_pending))) + cpufreq_stats_reset_table(stats); + + old_index = stats->last_index; + new_index = freq_table_get_index(stats, new_freq); + + /* We can't do stats->time_in_state[-1]= .. */ + if (unlikely(old_index == -1 || new_index == -1 || old_index == new_index)) + return; + + cpufreq_stats_update(stats, stats->last_time); + + stats->last_index = new_index; + stats->trans_table[old_index * stats->max_state + new_index]++; + stats->total_trans++; +} -- cgit v1.3.1