Thanks!
On Thu, Jun 20, 2019 at 5:41 PM Sibi Sankar <si...@codeaurora.org> wrote: > > Hey Hsin-Yi, Chanwoo > > On 2019-06-20 15:02, Hsin-Yi Wang wrote: > > Hi Chanwoo Choi, Saravana Kannan and Sibi Sankar, > > > > I've also tested Sibi Sankar's patch[1] locally with mt8183-cci, and > > it works fine too! > > It'd be great if Sibi Sankar or anyone who is familiar with the > > original design can finish this implementation. But if no one has time > > to do that, I think I can also help on address the comments. Thanks! > > Now that we have a user :) I am happy > to repost the patch with the comments > addressed. > > https://lkml.org/lkml/2019/6/14/4 > Also with ^^ patch and few more in the > series the dt parsing of required-opps > should get further simplified. > > > > > > > [1] > > [RFC,2/9] OPP: Export a number of helpers to prevent code duplication > > - https://patchwork.kernel.org/patch/10875199/ > > [RFC,3/9] PM / devfreq: Add cpu based scaling support to > > passive_governor > > - https://patchwork.kernel.org/patch/10875195/ > > > > Hsin-Yi > > > > On Thu, Jun 20, 2019 at 2:56 PM Chanwoo Choi <cw00.c...@samsung.com> > > wrote: > >> > >> + Sibi Sankar > >> > >> Hi, Hsin-Yi Wang, Saravana Kannan and Sibi Sankar > >> > >> I summarized the history of the related patch about this title. > >> > >> Firstly, > >> As I knew, Saravana sent the patch[1] which contains > >> 'governor_cpufreq_map.c' last year. According to the Myungoo's > >> comment, > >> > >> Secondly, > >> Sibi Sankar modified the 'governor_passive.c'[2] in order to support > >> the mapping between cpu frequency and device frequency. > >> Unfortunately, Sibi Sankar stopped the development about this > >> because he had found the other method to get his purpose as I knew. > >> > >> Thirdly, > >> Hsin-Yi Wang send the original patch of Saravana without modification. > >> > >> > >> Sincerely, I think that the mapping between cpu frequency and device > >> frequency is necessary. And I prefer the Sibi's approach which > >> implements > >> stuff to the existing 'passive' governor. > >> > >> We need to discuss about how to implement them by whom. > >> > >> > >> [1] [v3,1/2] PM / devfreq: Generic CPU frequency to device frequency > >> mapping governor > >> - https://patchwork.kernel.org/patch/10553171/ > >> > >> [2] > >> [PATCH RFC 0/9] Add CPU based scaling support to Passive governor > >> - > >> https://lore.kernel.org/lkml/08c3cff8c39e3d82e044db93e992d...@codeaurora.org/T/ > >> [PATCH RFC 3/9] PM / devfreq: Add cpu based scaling support to > >> passive_governor > >> - > >> https://lore.kernel.org/lkml/08c3cff8c39e3d82e044db93e992d...@codeaurora.org/T/#m1cafb7baf687d2a680d39c85d3ec7d1b590b68fc > >> > >> > >> Best Regards, > >> Chanwoo Choi > >> > >> On 19. 6. 18. 오후 1:14, Hsin-Yi Wang wrote: > >> > From: Saravana Kannan <skan...@codeaurora.org> > >> > > >> > From: Saravana Kannan <skan...@codeaurora.org> > >> > > >> > Many CPU architectures have caches that can scale independent of the > >> > CPUs. > >> > Frequency scaling of the caches is necessary to make sure the cache is > >> > not > >> > a performance bottleneck that leads to poor performance and power. The > >> > same > >> > idea applies for RAM/DDR. > >> > > >> > To achieve this, this patch adds a generic devfreq governor that takes > >> > the > >> > current frequency of each CPU frequency domain and then adjusts the > >> > frequency of the cache (or any devfreq device) based on the frequency of > >> > the CPUs. It listens to CPU frequency transition notifiers to keep itself > >> > up to date on the current CPU frequency. > >> > > >> > To decide the frequency of the device, the governor does one of the > >> > following: > >> > > >> > * Uses a CPU frequency to device frequency mapping table > >> > - Either one mapping table used for all CPU freq policies (typically > >> > used > >> > for system with homogeneous cores/clusters that have the same OPPs). > >> > - One mapping table per CPU freq policy (typically used for ASMP > >> > systems > >> > with heterogeneous CPUs with different OPPs) > >> > > >> > OR > >> > > >> > * Scales the device frequency in proportion to the CPU frequency. So, if > >> > the CPUs are running at their max frequency, the device runs at its max > >> > frequency. If the CPUs are running at their min frequency, the device > >> > runs at its min frequency. And interpolated for frequencies in between. > >> > > >> > Signed-off-by: Saravana Kannan <skan...@codeaurora.org> > >> > Signed-off-by: Hsin-Yi Wang <hsi...@chromium.org> > >> > --- > >> > .../bindings/devfreq/devfreq-cpufreq-map.txt | 53 ++ > >> > drivers/devfreq/Kconfig | 8 + > >> > drivers/devfreq/Makefile | 1 + > >> > drivers/devfreq/governor_cpufreq_map.c | 583 ++++++++++++++++++ > >> > 4 files changed, 645 insertions(+) > >> > create mode 100644 > >> > Documentation/devicetree/bindings/devfreq/devfreq-cpufreq-map.txt > >> > create mode 100644 drivers/devfreq/governor_cpufreq_map.c > >> > > >> > diff --git > >> > a/Documentation/devicetree/bindings/devfreq/devfreq-cpufreq-map.txt > >> > b/Documentation/devicetree/bindings/devfreq/devfreq-cpufreq-map.txt > >> > new file mode 100644 > >> > index 000000000000..982a30bcfc86 > >> > --- /dev/null > >> > +++ b/Documentation/devicetree/bindings/devfreq/devfreq-cpufreq-map.txt > >> > @@ -0,0 +1,53 @@ > >> > +Devfreq CPUfreq governor > >> > + > >> > +devfreq-cpufreq-map is a parent device that contains one or more child > >> > devices. > >> > +Each child device provides CPU frequency to device frequency mapping > >> > for a > >> > +specific device. Examples of devices that could use this are: DDR, > >> > cache and > >> > +CCI. > >> > + > >> > +Parent device name shall be "devfreq-cpufreq-map". > >> > + > >> > +Required child device properties: > >> > +- cpu-to-dev-map, or cpu-to-dev-map-<X>: > >> > + A list of tuples where each tuple consists of a > >> > + CPU frequency (KHz) and the corresponding device > >> > + frequency. CPU frequencies not listed in the table > >> > + will use the device frequency that corresponds to > >> > the > >> > + next rounded up CPU frequency. > >> > + Use "cpu-to-dev-map" if all CPUs in the system > >> > should > >> > + share same mapping. > >> > + Use cpu-to-dev-map-<cpuid> to describe different > >> > + mappings for different CPUs. The property should be > >> > + listed only for the first CPU if multiple CPUs are > >> > + synchronous. > >> > +- target-dev: Phandle to device that this mapping > >> > applies to. > >> > + > >> > +Example: > >> > + devfreq-cpufreq-map { > >> > + cpubw-cpufreq { > >> > + target-dev = <&cpubw>; > >> > + cpu-to-dev-map = > >> > + < 300000 1144000 >, > >> > + < 422400 2288000 >, > >> > + < 652800 3051000 >, > >> > + < 883200 5996000 >, > >> > + < 1190400 8056000 >, > >> > + < 1497600 10101000 >, > >> > + < 1728000 12145000 >, > >> > + < 2649600 16250000 >; > >> > + }; > >> > + > >> > + cache-cpufreq { > >> > + target-dev = <&cache>; > >> > + cpu-to-dev-map = > >> > + < 300000 300000 >, > >> > + < 422400 422400 >, > >> > + < 652800 499200 >, > >> > + < 883200 576000 >, > >> > + < 960000 960000 >, > >> > + < 1497600 1036800 >, > >> > + < 1574400 1574400 >, > >> > + < 1728000 1651200 >, > >> > + < 2649600 1728000 >; > >> > + }; > >> > + }; > >> > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > >> > index 0c8204d6b78a..0303f5a400b6 100644 > >> > --- a/drivers/devfreq/Kconfig > >> > +++ b/drivers/devfreq/Kconfig > >> > @@ -74,6 +74,14 @@ config DEVFREQ_GOV_PASSIVE > >> > through sysfs entries. The passive governor recommends that > >> > devfreq device uses the OPP table to get the frequency/voltage. > >> > > >> > +config DEVFREQ_GOV_CPUFREQ_MAP > >> > + tristate "CPUfreq Map" > >> > + depends on CPU_FREQ > >> > + help > >> > + Chooses frequency based on the online CPUs' current frequency > >> > and a > >> > + CPU frequency to device frequency mapping table(s). This governor > >> > + can be useful for controlling devices such as DDR, cache, CCI, > >> > etc. > >> > + > >> > comment "DEVFREQ Drivers" > >> > > >> > config ARM_EXYNOS_BUS_DEVFREQ > >> > diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile > >> > index 817dde779f16..81141e2c784f 100644 > >> > --- a/drivers/devfreq/Makefile > >> > +++ b/drivers/devfreq/Makefile > >> > @@ -6,6 +6,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE) += > >> > governor_performance.o > >> > obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o > >> > obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o > >> > obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o > >> > +obj-$(CONFIG_DEVFREQ_GOV_CPUFREQ_MAP) += governor_cpufreq_map.o > >> > > >> > # DEVFREQ Drivers > >> > obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o > >> > diff --git a/drivers/devfreq/governor_cpufreq_map.c > >> > b/drivers/devfreq/governor_cpufreq_map.c > >> > new file mode 100644 > >> > index 000000000000..084a3ffb8f54 > >> > --- /dev/null > >> > +++ b/drivers/devfreq/governor_cpufreq_map.c > >> > @@ -0,0 +1,583 @@ > >> > +// SPDX-License-Identifier: GPL-2.0 > >> > +/* > >> > + * Copyright (c) 2014-2015, 2018, The Linux Foundation. All rights > >> > reserved. > >> > + */ > >> > + > >> > +#define pr_fmt(fmt) "dev-cpufreq-map: " fmt > >> > + > >> > +#include <linux/devfreq.h> > >> > +#include <linux/cpu.h> > >> > +#include <linux/cpufreq.h> > >> > +#include <linux/cpumask.h> > >> > +#include <linux/slab.h> > >> > +#include <linux/platform_device.h> > >> > +#include <linux/of.h> > >> > +#include <linux/module.h> > >> > +#include "governor.h" > >> > + > >> > +struct cpu_state { > >> > + unsigned int freq; > >> > + unsigned int min_freq; > >> > + unsigned int max_freq; > >> > + unsigned int first_cpu; > >> > +}; > >> > +static struct cpu_state *state[NR_CPUS]; > >> > +static int cpufreq_cnt; > >> > + > >> > +struct freq_map { > >> > + unsigned int cpu_khz; > >> > + unsigned int target_freq; > >> > +}; > >> > + > >> > +struct devfreq_node { > >> > + struct devfreq *df; > >> > + void *orig_data; > >> > + struct device *dev; > >> > + struct device_node *of_node; > >> > + struct list_head list; > >> > + struct freq_map **map; > >> > + struct freq_map *common_map; > >> > +}; > >> > +static LIST_HEAD(devfreq_list); > >> > +static DEFINE_MUTEX(state_lock); > >> > +static DEFINE_MUTEX(cpufreq_reg_lock); > >> > + > >> > +static void update_all_devfreqs(void) > >> > +{ > >> > + struct devfreq_node *node; > >> > + > >> > + list_for_each_entry(node, &devfreq_list, list) { > >> > + struct devfreq *df = node->df; > >> > + > >> > + if (!node->df) > >> > + continue; > >> > + mutex_lock(&df->lock); > >> > + update_devfreq(df); > >> > + mutex_unlock(&df->lock); > >> > + > >> > + } > >> > +} > >> > + > >> > +static struct devfreq_node *find_devfreq_node(struct device *dev) > >> > +{ > >> > + struct devfreq_node *node; > >> > + > >> > + list_for_each_entry(node, &devfreq_list, list) > >> > + if (node->dev == dev || node->of_node == dev->of_node) > >> > + return node; > >> > + > >> > + return NULL; > >> > +} > >> > + > >> > +/* ==================== cpufreq part ==================== */ > >> > +static struct cpu_state *add_policy(struct cpufreq_policy *policy) > >> > +{ > >> > + struct cpu_state *new_state; > >> > + unsigned int cpu, first_cpu; > >> > + > >> > + new_state = kzalloc(sizeof(struct cpu_state), GFP_KERNEL); > >> > + if (!new_state) > >> > + return NULL; > >> > + > >> > + first_cpu = cpumask_first(policy->related_cpus); > >> > + new_state->first_cpu = first_cpu; > >> > + new_state->freq = policy->cur; > >> > + new_state->min_freq = policy->cpuinfo.min_freq; > >> > + new_state->max_freq = policy->cpuinfo.max_freq; > >> > + > >> > + for_each_cpu(cpu, policy->related_cpus) > >> > + state[cpu] = new_state; > >> > + > >> > + return new_state; > >> > +} > >> > + > >> > +static int cpufreq_trans_notifier(struct notifier_block *nb, > >> > + unsigned long event, void *data) > >> > +{ > >> > + struct cpufreq_freqs *freq = data; > >> > + struct cpu_state *s; > >> > + struct cpufreq_policy *policy = NULL; > >> > + > >> > + if (event != CPUFREQ_POSTCHANGE) > >> > + return 0; > >> > + > >> > + mutex_lock(&state_lock); > >> > + > >> > + s = state[freq->cpu]; > >> > + if (!s) { > >> > + policy = cpufreq_cpu_get(freq->cpu); > >> > + if (policy) { > >> > + s = add_policy(policy); > >> > + cpufreq_cpu_put(policy); > >> > + } > >> > + } > >> > + if (!s) > >> > + goto out; > >> > + > >> > + if (s->freq != freq->new || policy) { > >> > + s->freq = freq->new; > >> > + update_all_devfreqs(); > >> > + } > >> > + > >> > +out: > >> > + mutex_unlock(&state_lock); > >> > + return 0; > >> > +} > >> > + > >> > +static struct notifier_block cpufreq_trans_nb = { > >> > + .notifier_call = cpufreq_trans_notifier > >> > +}; > >> > + > >> > +static int register_cpufreq(void) > >> > +{ > >> > + int ret = 0; > >> > + unsigned int cpu; > >> > + struct cpufreq_policy *policy; > >> > + > >> > + mutex_lock(&cpufreq_reg_lock); > >> > + > >> > + if (cpufreq_cnt) > >> > + goto cnt_not_zero; > >> > + > >> > + get_online_cpus(); > >> > + ret = cpufreq_register_notifier(&cpufreq_trans_nb, > >> > + CPUFREQ_TRANSITION_NOTIFIER); > >> > + if (ret) > >> > + goto out; > >> > + > >> > + for_each_online_cpu(cpu) { > >> > + policy = cpufreq_cpu_get(cpu); > >> > + if (policy) { > >> > + add_policy(policy); > >> > + cpufreq_cpu_put(policy); > >> > + } > >> > + } > >> > +out: > >> > + put_online_cpus(); > >> > +cnt_not_zero: > >> > + if (!ret) > >> > + cpufreq_cnt++; > >> > + mutex_unlock(&cpufreq_reg_lock); > >> > + return ret; > >> > +} > >> > + > >> > +static int unregister_cpufreq(void) > >> > +{ > >> > + int ret = 0; > >> > + int cpu; > >> > + > >> > + mutex_lock(&cpufreq_reg_lock); > >> > + > >> > + if (cpufreq_cnt > 1) > >> > + goto out; > >> > + > >> > + cpufreq_unregister_notifier(&cpufreq_trans_nb, > >> > + CPUFREQ_TRANSITION_NOTIFIER); > >> > + > >> > + for (cpu = ARRAY_SIZE(state) - 1; cpu >= 0; cpu--) { > >> > + if (!state[cpu]) > >> > + continue; > >> > + if (state[cpu]->first_cpu == cpu) > >> > + kfree(state[cpu]); > >> > + state[cpu] = NULL; > >> > + } > >> > + > >> > +out: > >> > + cpufreq_cnt--; > >> > + mutex_unlock(&cpufreq_reg_lock); > >> > + return ret; > >> > +} > >> > + > >> > +/* ==================== devfreq part ==================== */ > >> > + > >> > +static unsigned int interpolate_freq(struct devfreq *df, unsigned int > >> > cpu) > >> > +{ > >> > + unsigned long *freq_table = df->profile->freq_table; > >> > + unsigned int cpu_min = state[cpu]->min_freq; > >> > + unsigned int cpu_max = state[cpu]->max_freq; > >> > + unsigned int cpu_freq = state[cpu]->freq; > >> > + unsigned int dev_min, dev_max, cpu_percent; > >> > + > >> > + if (freq_table) { > >> > + dev_min = freq_table[0]; > >> > + dev_max = freq_table[df->profile->max_state - 1]; > >> > + } else { > >> > + if (df->max_freq <= df->min_freq) > >> > + return 0; > >> > + dev_min = df->min_freq; > >> > + dev_max = df->max_freq; > >> > + } > >> > + > >> > + cpu_percent = ((cpu_freq - cpu_min) * 100) / (cpu_max - cpu_min); > >> > + return dev_min + mult_frac(dev_max - dev_min, cpu_percent, 100); > >> > +} > >> > + > >> > +static unsigned int cpu_to_dev_freq(struct devfreq *df, unsigned int > >> > cpu) > >> > +{ > >> > + struct freq_map *map = NULL; > >> > + unsigned int cpu_khz = 0, freq; > >> > + struct devfreq_node *n = df->data; > >> > + > >> > + if (!state[cpu] || state[cpu]->first_cpu != cpu) { > >> > + freq = 0; > >> > + goto out; > >> > + } > >> > + > >> > + if (n->common_map) > >> > + map = n->common_map; > >> > + else if (n->map) > >> > + map = n->map[cpu]; > >> > + > >> > + cpu_khz = state[cpu]->freq; > >> > + > >> > + if (!map) { > >> > + freq = interpolate_freq(df, cpu); > >> > + goto out; > >> > + } > >> > + > >> > + while (map->cpu_khz && map->cpu_khz < cpu_khz) > >> > + map++; > >> > + if (!map->cpu_khz) > >> > + map--; > >> > + freq = map->target_freq; > >> > + > >> > +out: > >> > + dev_dbg(df->dev.parent, "CPU%u: %d -> dev: %u\n", cpu, cpu_khz, > >> > freq); > >> > + return freq; > >> > +} > >> > + > >> > +static int devfreq_cpufreq_get_freq(struct devfreq *df, > >> > + unsigned long *freq) > >> > +{ > >> > + unsigned int cpu, tgt_freq = 0; > >> > + struct devfreq_node *node; > >> > + > >> > + node = df->data; > >> > + if (!node) { > >> > + pr_err("Unable to find devfreq node!\n"); > >> > + return -ENODEV; > >> > + } > >> > + > >> > + for_each_possible_cpu(cpu) > >> > + tgt_freq = max(tgt_freq, cpu_to_dev_freq(df, cpu)); > >> > + > >> > + *freq = tgt_freq; > >> > + return 0; > >> > +} > >> > + > >> > +static unsigned int show_table(char *buf, unsigned int len, > >> > + struct freq_map *map) > >> > +{ > >> > + unsigned int cnt = 0; > >> > + > >> > + cnt += snprintf(buf + cnt, len - cnt, "CPU freq\tDevice freq\n"); > >> > + > >> > + while (map->cpu_khz && cnt < len) { > >> > + cnt += snprintf(buf + cnt, len - cnt, "%8u\t%11u\n", > >> > + map->cpu_khz, map->target_freq); > >> > + map++; > >> > + } > >> > + if (cnt < len) > >> > + cnt += snprintf(buf + cnt, len - cnt, "\n"); > >> > + > >> > + return cnt; > >> > +} > >> > + > >> > +static ssize_t freq_map_show(struct device *dev, struct > >> > device_attribute *attr, > >> > + char *buf) > >> > +{ > >> > + struct devfreq *df = to_devfreq(dev); > >> > + struct devfreq_node *n = df->data; > >> > + struct freq_map *map; > >> > + unsigned int cnt = 0, cpu; > >> > + > >> > + mutex_lock(&state_lock); > >> > + if (n->common_map) { > >> > + map = n->common_map; > >> > + cnt += snprintf(buf + cnt, PAGE_SIZE - cnt, > >> > + "Common table for all CPUs:\n"); > >> > + cnt += show_table(buf + cnt, PAGE_SIZE - cnt, map); > >> > + } else if (n->map) { > >> > + for_each_possible_cpu(cpu) { > >> > + map = n->map[cpu]; > >> > + if (!map) > >> > + continue; > >> > + cnt += snprintf(buf + cnt, PAGE_SIZE - cnt, > >> > + "CPU %u:\n", cpu); > >> > + if (cnt >= PAGE_SIZE) > >> > + break; > >> > + cnt += show_table(buf + cnt, PAGE_SIZE - cnt, map); > >> > + if (cnt >= PAGE_SIZE) > >> > + break; > >> > + } > >> > + } else { > >> > + cnt += snprintf(buf + cnt, PAGE_SIZE - cnt, > >> > + "Device freq interpolated based on CPU > >> > freq\n"); > >> > + } > >> > + mutex_unlock(&state_lock); > >> > + > >> > + return cnt; > >> > +} > >> > + > >> > +static DEVICE_ATTR_RO(freq_map); > >> > +static struct attribute *dev_attr[] = { > >> > + &dev_attr_freq_map.attr, > >> > + NULL, > >> > +}; > >> > + > >> > +static struct attribute_group dev_attr_group = { > >> > + .name = "cpufreq-map", > >> > + .attrs = dev_attr, > >> > +}; > >> > + > >> > +static int devfreq_cpufreq_gov_start(struct devfreq *devfreq) > >> > +{ > >> > + int ret = 0; > >> > + struct devfreq_node *node; > >> > + bool alloc = false; > >> > + > >> > + ret = register_cpufreq(); > >> > + if (ret) > >> > + return ret; > >> > + > >> > + ret = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group); > >> > + if (ret) { > >> > + unregister_cpufreq(); > >> > + return ret; > >> > + } > >> > + > >> > + mutex_lock(&state_lock); > >> > + > >> > + node = find_devfreq_node(devfreq->dev.parent); > >> > + if (node == NULL) { > >> > + node = kzalloc(sizeof(struct devfreq_node), GFP_KERNEL); > >> > + if (!node) { > >> > + ret = -ENOMEM; > >> > + goto alloc_fail; > >> > + } > >> > + alloc = true; > >> > + node->dev = devfreq->dev.parent; > >> > + list_add_tail(&node->list, &devfreq_list); > >> > + } > >> > + node->df = devfreq; > >> > + node->orig_data = devfreq->data; > >> > + devfreq->data = node; > >> > + > >> > + mutex_lock(&devfreq->lock); > >> > + ret = update_devfreq(devfreq); > >> > + mutex_unlock(&devfreq->lock); > >> > + if (ret) { > >> > + pr_err("Freq update failed!\n"); > >> > + goto update_fail; > >> > + } > >> > + > >> > + mutex_unlock(&state_lock); > >> > + return 0; > >> > + > >> > +update_fail: > >> > + devfreq->data = node->orig_data; > >> > + if (alloc) { > >> > + list_del(&node->list); > >> > + kfree(node); > >> > + } > >> > +alloc_fail: > >> > + mutex_unlock(&state_lock); > >> > + sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group); > >> > + unregister_cpufreq(); > >> > + return ret; > >> > +} > >> > + > >> > +static void devfreq_cpufreq_gov_stop(struct devfreq *devfreq) > >> > +{ > >> > + struct devfreq_node *node = devfreq->data; > >> > + > >> > + mutex_lock(&state_lock); > >> > + devfreq->data = node->orig_data; > >> > + if (node->map || node->common_map) { > >> > + node->df = NULL; > >> > + } else { > >> > + list_del(&node->list); > >> > + kfree(node); > >> > + } > >> > + mutex_unlock(&state_lock); > >> > + > >> > + sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group); > >> > + unregister_cpufreq(); > >> > +} > >> > + > >> > +static int devfreq_cpufreq_ev_handler(struct devfreq *devfreq, > >> > + unsigned int event, void *data) > >> > +{ > >> > + int ret; > >> > + > >> > + switch (event) { > >> > + case DEVFREQ_GOV_START: > >> > + > >> > + ret = devfreq_cpufreq_gov_start(devfreq); > >> > + if (ret) { > >> > + pr_err("Governor start failed!\n"); > >> > + return ret; > >> > + } > >> > + pr_debug("Enabled CPUfreq-map governor\n"); > >> > + break; > >> > + > >> > + case DEVFREQ_GOV_STOP: > >> > + > >> > + devfreq_cpufreq_gov_stop(devfreq); > >> > + pr_debug("Disabled dev CPUfreq-map governor\n"); > >> > + break; > >> > + } > >> > + > >> > + return 0; > >> > +} > >> > + > >> > +static struct devfreq_governor devfreq_cpufreq = { > >> > + .name = "cpufreq-map", > >> > + .get_target_freq = devfreq_cpufreq_get_freq, > >> > + .event_handler = devfreq_cpufreq_ev_handler, > >> > +}; > >> > + > >> > +#define NUM_COLS 2 > >> > +static struct freq_map *read_tbl(struct device_node *of_node, char > >> > *prop_name) > >> > +{ > >> > + int len, nf, i, j; > >> > + u32 data; > >> > + struct freq_map *tbl; > >> > + > >> > + if (!of_find_property(of_node, prop_name, &len)) > >> > + return NULL; > >> > + len /= sizeof(data); > >> > + > >> > + if (len % NUM_COLS || len == 0) > >> > + return NULL; > >> > + nf = len / NUM_COLS; > >> > + > >> > + tbl = kzalloc((nf + 1) * sizeof(*tbl), GFP_KERNEL); > >> > + if (!tbl) > >> > + return NULL; > >> > + > >> > + for (i = 0, j = 0; i < nf; i++, j += 2) { > >> > + of_property_read_u32_index(of_node, prop_name, j, &data); > >> > + tbl[i].cpu_khz = data; > >> > + > >> > + of_property_read_u32_index(of_node, prop_name, j + 1, > >> > &data); > >> > + tbl[i].target_freq = data; > >> > + } > >> > + tbl[i].cpu_khz = 0; > >> > + > >> > + return tbl; > >> > +} > >> > + > >> > +#define PROP_TARGET "target-dev" > >> > +#define PROP_TABLE "cpu-to-dev-map" > >> > +static int add_table_from_of(struct device_node *of_node) > >> > +{ > >> > + struct device_node *target_of_node; > >> > + struct devfreq_node *node; > >> > + struct freq_map *common_tbl; > >> > + struct freq_map **tbl_list = NULL; > >> > + static char prop_name[] = PROP_TABLE "-999999"; > >> > + int cpu, ret, cnt = 0, prop_sz = ARRAY_SIZE(prop_name); > >> > + > >> > + target_of_node = of_parse_phandle(of_node, PROP_TARGET, 0); > >> > + if (!target_of_node) > >> > + return -EINVAL; > >> > + > >> > + node = kzalloc(sizeof(struct devfreq_node), GFP_KERNEL); > >> > + if (!node) > >> > + return -ENOMEM; > >> > + > >> > + common_tbl = read_tbl(of_node, PROP_TABLE); > >> > + if (!common_tbl) { > >> > + tbl_list = kzalloc(sizeof(*tbl_list) * NR_CPUS, > >> > GFP_KERNEL); > >> > + if (!tbl_list) { > >> > + ret = -ENOMEM; > >> > + goto err_list; > >> > + } > >> > + > >> > + for_each_possible_cpu(cpu) { > >> > + ret = snprintf(prop_name, prop_sz, "%s-%d", > >> > + PROP_TABLE, cpu); > >> > + if (ret >= prop_sz) { > >> > + pr_warn("More CPUs than I can handle!\n"); > >> > + pr_warn("Skipping rest of the tables!\n"); > >> > + break; > >> > + } > >> > + tbl_list[cpu] = read_tbl(of_node, prop_name); > >> > + if (tbl_list[cpu]) > >> > + cnt++; > >> > + } > >> > + } > >> > + if (!common_tbl && !cnt) { > >> > + ret = -EINVAL; > >> > + goto err_tbl; > >> > + } > >> > + > >> > + mutex_lock(&state_lock); > >> > + node->of_node = target_of_node; > >> > + node->map = tbl_list; > >> > + node->common_map = common_tbl; > >> > + list_add_tail(&node->list, &devfreq_list); > >> > + mutex_unlock(&state_lock); > >> > + > >> > + return 0; > >> > +err_tbl: > >> > + kfree(tbl_list); > >> > +err_list: > >> > + kfree(node); > >> > + return ret; > >> > +} > >> > + > >> > +static int __init devfreq_cpufreq_init(void) > >> > +{ > >> > + int ret; > >> > + struct device_node *of_par, *of_child; > >> > + > >> > + of_par = of_find_node_by_name(NULL, "devfreq-cpufreq-map"); > >> > + if (of_par) { > >> > + for_each_child_of_node(of_par, of_child) { > >> > + ret = add_table_from_of(of_child); > >> > + if (ret) > >> > + pr_err("Parsing %s failed!\n", > >> > of_child->name); > >> > + else > >> > + pr_debug("Parsed %s.\n", of_child->name); > >> > + } > >> > + of_node_put(of_par); > >> > + } else { > >> > + pr_info("No tables parsed from DT.\n"); > >> > + } > >> > + > >> > + ret = devfreq_add_governor(&devfreq_cpufreq); > >> > + if (ret) { > >> > + pr_err("cpufreq-map governor add failed!\n"); > >> > + return ret; > >> > + } > >> > + > >> > + return 0; > >> > +} > >> > +subsys_initcall(devfreq_cpufreq_init); > >> > + > >> > +static void __exit devfreq_cpufreq_exit(void) > >> > +{ > >> > + int ret, cpu; > >> > + struct devfreq_node *node, *tmp; > >> > + > >> > + ret = devfreq_remove_governor(&devfreq_cpufreq); > >> > + if (ret) > >> > + pr_err("cpufreq-map governor remove failed!\n"); > >> > + > >> > + mutex_lock(&state_lock); > >> > + list_for_each_entry_safe(node, tmp, &devfreq_list, list) { > >> > + kfree(node->common_map); > >> > + for_each_possible_cpu(cpu) > >> > + kfree(node->map[cpu]); > >> > + kfree(node->map); > >> > + list_del(&node->list); > >> > + kfree(node); > >> > + } > >> > + mutex_unlock(&state_lock); > >> > +} > >> > +module_exit(devfreq_cpufreq_exit); > >> > + > >> > +MODULE_DESCRIPTION("devfreq gov that sets dev freq based on current CPU > >> > freq"); > >> > +MODULE_LICENSE("GPL v2"); > >> > > > -- > -- Sibi Sankar -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project.
