diff options
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/Kconfig | 15 | ||||
| -rw-r--r-- | kernel/power/Makefile | 2 | ||||
| -rw-r--r-- | kernel/power/energy_model.c | 258 | ||||
| -rw-r--r-- | kernel/power/main.c | 15 | ||||
| -rw-r--r-- | kernel/power/qos.c | 23 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 24 |
6 files changed, 296 insertions, 41 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 3a6c2f87699e..f8fe57d1022e 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -298,3 +298,18 @@ config PM_GENERIC_DOMAINS_OF config CPU_PM bool + +config ENERGY_MODEL + bool "Energy Model for CPUs" + depends on SMP + depends on CPU_FREQ + default n + help + Several subsystems (thermal and/or the task scheduler for example) + can leverage information about the energy consumed by CPUs to make + smarter decisions. This config option enables the framework from + which subsystems can access the energy models. + + The exact usage of the energy model is subsystem-dependent. + + If in doubt, say N. diff --git a/kernel/power/Makefile b/kernel/power/Makefile index a3f79f0eef36..e7e47d9be1e5 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -15,3 +15,5 @@ obj-$(CONFIG_PM_AUTOSLEEP) += autosleep.o obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o + +obj-$(CONFIG_ENERGY_MODEL) += energy_model.o diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c new file mode 100644 index 000000000000..7d66ee68aaaf --- /dev/null +++ b/kernel/power/energy_model.c @@ -0,0 +1,258 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Energy Model of CPUs + * + * Copyright (c) 2018, Arm ltd. + * Written by: Quentin Perret, Arm ltd. + */ + +#define pr_fmt(fmt) "energy_model: " fmt + +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/debugfs.h> +#include <linux/energy_model.h> +#include <linux/sched/topology.h> +#include <linux/slab.h> + +/* Mapping of each CPU to the performance domain to which it belongs. */ +static DEFINE_PER_CPU(struct em_perf_domain *, em_data); + +/* + * Mutex serializing the registrations of performance domains and letting + * callbacks defined by drivers sleep. + */ +static DEFINE_MUTEX(em_pd_mutex); + +#ifdef CONFIG_DEBUG_FS +static struct dentry *rootdir; + +static void em_debug_create_cs(struct em_cap_state *cs, struct dentry *pd) +{ + struct dentry *d; + char name[24]; + + snprintf(name, sizeof(name), "cs:%lu", cs->frequency); + + /* Create per-cs directory */ + d = debugfs_create_dir(name, pd); + debugfs_create_ulong("frequency", 0444, d, &cs->frequency); + debugfs_create_ulong("power", 0444, d, &cs->power); + debugfs_create_ulong("cost", 0444, d, &cs->cost); +} + +static int em_debug_cpus_show(struct seq_file *s, void *unused) +{ + seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private))); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(em_debug_cpus); + +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) +{ + struct dentry *d; + char name[8]; + int i; + + snprintf(name, sizeof(name), "pd%d", cpu); + + /* Create the directory of the performance domain */ + d = debugfs_create_dir(name, rootdir); + + debugfs_create_file("cpus", 0444, d, pd->cpus, &em_debug_cpus_fops); + + /* Create a sub-directory for each capacity state */ + for (i = 0; i < pd->nr_cap_states; i++) + em_debug_create_cs(&pd->table[i], d); +} + +static int __init em_debug_init(void) +{ + /* Create /sys/kernel/debug/energy_model directory */ + rootdir = debugfs_create_dir("energy_model", NULL); + + return 0; +} +core_initcall(em_debug_init); +#else /* CONFIG_DEBUG_FS */ +static void em_debug_create_pd(struct em_perf_domain *pd, int cpu) {} +#endif +static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, + struct em_data_callback *cb) +{ + unsigned long opp_eff, prev_opp_eff = ULONG_MAX; + unsigned long power, freq, prev_freq = 0; + int i, ret, cpu = cpumask_first(span); + struct em_cap_state *table; + struct em_perf_domain *pd; + u64 fmax; + + if (!cb->active_power) + return NULL; + + pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); + if (!pd) + return NULL; + + table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); + if (!table) + goto free_pd; + + /* Build the list of capacity states for this performance domain */ + for (i = 0, freq = 0; i < nr_states; i++, freq++) { + /* + * active_power() is a driver callback which ceils 'freq' to + * lowest capacity state of 'cpu' above 'freq' and updates + * 'power' and 'freq' accordingly. + */ + ret = cb->active_power(&power, &freq, cpu); + if (ret) { + pr_err("pd%d: invalid cap. state: %d\n", cpu, ret); + goto free_cs_table; + } + + /* + * We expect the driver callback to increase the frequency for + * higher capacity states. + */ + if (freq <= prev_freq) { + pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); + goto free_cs_table; + } + + /* + * The power returned by active_state() is expected to be + * positive, in milli-watts and to fit into 16 bits. + */ + if (!power || power > EM_CPU_MAX_POWER) { + pr_err("pd%d: invalid power: %lu\n", cpu, power); + goto free_cs_table; + } + + table[i].power = power; + table[i].frequency = prev_freq = freq; + + /* + * The hertz/watts efficiency ratio should decrease as the + * frequency grows on sane platforms. But this isn't always + * true in practice so warn the user if a higher OPP is more + * power efficient than a lower one. + */ + opp_eff = freq / power; + if (opp_eff >= prev_opp_eff) + pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n", + cpu, i, i - 1); + prev_opp_eff = opp_eff; + } + + /* Compute the cost of each capacity_state. */ + fmax = (u64) table[nr_states - 1].frequency; + for (i = 0; i < nr_states; i++) { + table[i].cost = div64_u64(fmax * table[i].power, + table[i].frequency); + } + + pd->table = table; + pd->nr_cap_states = nr_states; + cpumask_copy(to_cpumask(pd->cpus), span); + + em_debug_create_pd(pd, cpu); + + return pd; + +free_cs_table: + kfree(table); +free_pd: + kfree(pd); + + return NULL; +} + +/** + * em_cpu_get() - Return the performance domain for a CPU + * @cpu : CPU to find the performance domain for + * + * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't + * exist. + */ +struct em_perf_domain *em_cpu_get(int cpu) +{ + return READ_ONCE(per_cpu(em_data, cpu)); +} +EXPORT_SYMBOL_GPL(em_cpu_get); + +/** + * em_register_perf_domain() - Register the Energy Model of a performance domain + * @span : Mask of CPUs in the performance domain + * @nr_states : Number of capacity states to register + * @cb : Callback functions providing the data of the Energy Model + * + * Create Energy Model tables for a performance domain using the callbacks + * defined in cb. + * + * If multiple clients register the same performance domain, all but the first + * registration will be ignored. + * + * Return 0 on success + */ +int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, + struct em_data_callback *cb) +{ + unsigned long cap, prev_cap = 0; + struct em_perf_domain *pd; + int cpu, ret = 0; + + if (!span || !nr_states || !cb) + return -EINVAL; + + /* + * Use a mutex to serialize the registration of performance domains and + * let the driver-defined callback functions sleep. + */ + mutex_lock(&em_pd_mutex); + + for_each_cpu(cpu, span) { + /* Make sure we don't register again an existing domain. */ + if (READ_ONCE(per_cpu(em_data, cpu))) { + ret = -EEXIST; + goto unlock; + } + + /* + * All CPUs of a domain must have the same micro-architecture + * since they all share the same table. + */ + cap = arch_scale_cpu_capacity(NULL, cpu); + if (prev_cap && prev_cap != cap) { + pr_err("CPUs of %*pbl must have the same capacity\n", + cpumask_pr_args(span)); + ret = -EINVAL; + goto unlock; + } + prev_cap = cap; + } + + /* Create the performance domain and add it to the Energy Model. */ + pd = em_create_pd(span, nr_states, cb); + if (!pd) { + ret = -EINVAL; + goto unlock; + } + + for_each_cpu(cpu, span) { + /* + * The per-cpu array can be read concurrently from em_cpu_get(). + * The barrier enforces the ordering needed to make sure readers + * can only access well formed em_perf_domain structs. + */ + smp_store_release(per_cpu_ptr(&em_data, cpu), pd); + } + + pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); +unlock: + mutex_unlock(&em_pd_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(em_register_perf_domain); diff --git a/kernel/power/main.c b/kernel/power/main.c index 35b50823d83b..98e76cad128b 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -318,23 +318,12 @@ static int suspend_stats_show(struct seq_file *s, void *unused) return 0; } - -static int suspend_stats_open(struct inode *inode, struct file *file) -{ - return single_open(file, suspend_stats_show, NULL); -} - -static const struct file_operations suspend_stats_operations = { - .open = suspend_stats_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; +DEFINE_SHOW_ATTRIBUTE(suspend_stats); static int __init pm_debugfs_init(void) { debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO, - NULL, NULL, &suspend_stats_operations); + NULL, NULL, &suspend_stats_fops); return 0; } diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 86d72ffb811b..9d22131afc1e 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -184,7 +184,7 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) c->target_value = value; } -static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused) +static int pm_qos_debug_show(struct seq_file *s, void *unused) { struct pm_qos_object *qos = (struct pm_qos_object *)s->private; struct pm_qos_constraints *c; @@ -245,18 +245,7 @@ out: return 0; } -static int pm_qos_dbg_open(struct inode *inode, struct file *file) -{ - return single_open(file, pm_qos_dbg_show_requests, - inode->i_private); -} - -static const struct file_operations pm_qos_debug_fops = { - .open = pm_qos_dbg_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; +DEFINE_SHOW_ATTRIBUTE(pm_qos_debug); /** * pm_qos_update_target - manages the constraints list and calls the notifiers @@ -593,10 +582,8 @@ static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d) qos->pm_qos_power_miscdev.name = qos->name; qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; - if (d) { - (void)debugfs_create_file(qos->name, S_IRUGO, d, - (void *)qos, &pm_qos_debug_fops); - } + debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos, + &pm_qos_debug_fops); return misc_register(&qos->pm_qos_power_miscdev); } @@ -696,8 +683,6 @@ static int __init pm_qos_power_init(void) BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); d = debugfs_create_dir("pm_qos", NULL); - if (IS_ERR_OR_NULL(d)) - d = NULL; for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { ret = register_pm_qos_misc(pm_qos_array[i], d); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 3d37c279c090..4802b039b89f 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -23,7 +23,7 @@ #include <linux/pm.h> #include <linux/device.h> #include <linux/init.h> -#include <linux/bootmem.h> +#include <linux/memblock.h> #include <linux/nmi.h> #include <linux/syscalls.h> #include <linux/console.h> @@ -105,7 +105,7 @@ unsigned long image_size; void __init hibernate_image_size_init(void) { - image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; + image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE; } /* @@ -963,7 +963,8 @@ void __init __register_nosave_region(unsigned long start_pfn, BUG_ON(!region); } else { /* This allocation cannot fail */ - region = memblock_virt_alloc(sizeof(struct nosave_region), 0); + region = memblock_alloc(sizeof(struct nosave_region), + SMP_CACHE_BYTES); } region->start_pfn = start_pfn; region->end_pfn = end_pfn; @@ -1214,14 +1215,16 @@ static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn) if (!pfn_valid(pfn)) return NULL; - page = pfn_to_page(pfn); - if (page_zone(page) != zone) + page = pfn_to_online_page(pfn); + if (!page || page_zone(page) != zone) return NULL; BUG_ON(!PageHighMem(page)); - if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) || - PageReserved(page)) + if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) + return NULL; + + if (PageReserved(page) || PageOffline(page)) return NULL; if (page_is_guard(page)) @@ -1276,8 +1279,8 @@ static struct page *saveable_page(struct zone *zone, unsigned long pfn) if (!pfn_valid(pfn)) return NULL; - page = pfn_to_page(pfn); - if (page_zone(page) != zone) + page = pfn_to_online_page(pfn); + if (!page || page_zone(page) != zone) return NULL; BUG_ON(PageHighMem(page)); @@ -1285,6 +1288,9 @@ static struct page *saveable_page(struct zone *zone, unsigned long pfn) if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) return NULL; + if (PageOffline(page)) + return NULL; + if (PageReserved(page) && (!kernel_page_present(page) || pfn_is_nosave(pfn))) return NULL; |