Hi Rafael,
Any inputs on this patch?
Thanks!
On 10/19/2017 12:19 PM, Prashanth Prakash wrote:
> Add support to expose idle statistics maintained by platform to
> userspace via sysfs in addition to other data of interest from
> each LPI(Low Power Idle) state.
>
> LPI described in section 8.4.4 of ACPI spec 6.1 provides different
> methods to obtain idle statistics maintained by the platform. These
> show a granular view of how each of the LPI state is being used at
> different level of hierarchy. sysfs data is exposed at each level in
> the hierarchy by creating a directory named 'lpi' at each level and
> the LPI state information is presented under it. Below is the
> representation of LPI information at one such level in the hierarchy
>
> .../ACPI00XX: XX/lpi
> |-> state0
> | |-> state_name
> | |-> residency
> | |-> usage
> | |-> wakeup_latency
> | |-> min_residency
> | |-> state_index
> | |-> enabled_parent_state
> |
> <<more states>>
>
> ACPI00XX can be ACPI0007(processor) or ACPI0010(processor container)
>
> stateX contains information related to a specific LPI state defined
> in the LPI ACPI tables.
>
> Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
> ---
> v3
> * Changed sysfs names to follow spec names (Rafael)
> * Added enabled_parent_state(Rafael) and state_index to sysfs entries
> state_index was added to make sense of enabled_parent_state
>
> Couldn't find a clean way to expose the hierarchical LPI information under
> cpuidle
>
> v2
> * Add Documentation/ABI/testing/sysfs-acpi-lpi
>
> v1
> * Drop flags, arch_flags and summary_stats field (Sudeep)
> * Create sysfs entries after we know that LPI will be used (Sudeep & Rafael)
>
> Documentation/ABI/testing/sysfs-acpi-lpi | 57 +++++
> drivers/acpi/processor_idle.c | 363 ++++++++++++++++++++++++++++++-
> include/acpi/processor.h | 14 ++
> 3 files changed, 432 insertions(+), 2 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-acpi-lpi
>
> diff --git a/Documentation/ABI/testing/sysfs-acpi-lpi b/Documentation/ABI/testing/sysfs-acpi-lpi
> new file mode 100644
> index 0000000..5f1c90a
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-acpi-lpi
> @@ -0,0 +1,57 @@
> +What: LPI sysfs interface for processor devices and containers
> +Date: 19-October-2017
> +KernelVersion: v4.15
> +Contact: linux-acpi@xxxxxxxxxxxxxxx
> +Description: LPI(Low Power Idle) described in section 8.4.4 of ACPI spec 6.1
> + provides different methods to obtain idle statistics maintained
> + by the platform. These show a granular view of how each of the
> + LPI state is being used at different level of processor hierarchy.
> + sysfs data is exposed at each level in the hierarchy by creating
> + a directory named 'lpi' at each level and the LPI state
> + information is presented under it. Below is the representation
> + of LPI information at one such level in the hierarchy.
> +
> + .../ACPI00XX: YY/lpi
> + |-> state0
> + | |-> state_name
> + | |-> wakeup_latency
> + | |-> min_residency
> + | |-> state_index
> + | |-> enabled_parent_state
> + | |-> residency
> + | |-> usage
> + |
> + |-> state1
> + | |-> state_name
> + | |-> wakeup_latency
> + | |-> min_residency
> + | |-> state_index
> + | |-> enabled_parent_state
> + | |-> residency
> + | |-> usage
> + |
> + <<more states>>
> +
> + ACPI00XX can be ACPI0007(processor device) or ACPI0010(processor
> + container) and the sysfs nodes for these ACPI devices can be
> + found under /sys/devices/LNXSYSTM:00
> +
> + stateX contains information related to a specific local LPI
> + state defined in the LPI ACPI tables under a owning hierarchy
> + node(ACPI0007 or ACPI0010).
> +
> + state_name - Name of the local LPI state
> + wakeup_latency - Worst case wake up latency(in micro seconds)
> + for the owning hierarchy node to exit from this
> + local LPI state
> + min_residency - Time in microseconds after which a state becomes
> + more energy effecient than a shallower state
> + residency - Total time spent(in micro seconds) by the owning
> + hierarchy node in this local idle state
> + usage - Number of times the owning hierarchy node entered
> + this local power state
> + state_index - Index 0 represents active state. The index(es) is
> + assigned starting from 1 as the states are
> + discovered in ACPI tables.
> + enabled_parent_state - Index of deepest local power state enabled
> + by this LPI state in parent processor node
> \ No newline at end of file
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 2736e25..ac6301a 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -947,6 +947,10 @@ struct acpi_lpi_states_array {
> struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
> };
>
> +static int acpi_lpi_sysfs_init(acpi_handle h,
> + struct acpi_lpi_states_array *info);
> +static int acpi_lpi_sysfs_exit(struct acpi_processor *pr);
> +
> static int obj_get_integer(union acpi_object *obj, u32 *value)
> {
> if (obj->type != ACPI_TYPE_INTEGER)
> @@ -956,6 +960,24 @@ static int obj_get_integer(union acpi_object *obj, u32 *value)
> return 0;
> }
>
> +static int obj_get_generic_addr(union acpi_object *obj,
> + struct acpi_generic_address *addr)
> +{
> + struct acpi_power_register *reg;
> +
> + if (obj->type != ACPI_TYPE_BUFFER)
> + return -EINVAL;
> +
> + reg = (struct acpi_power_register *)obj->buffer.pointer;
> + addr->space_id = reg->space_id;
> + addr->bit_width = reg->bit_width;
> + addr->bit_offset = reg->bit_offset;
> + addr->access_width = reg->access_size;
> + addr->address = reg->address;
> +
> + return 0;
> +}
> +
> static int acpi_processor_evaluate_lpi(acpi_handle handle,
> struct acpi_lpi_states_array *info)
> {
> @@ -1030,8 +1052,6 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle,
> continue;
> }
>
> - /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
> -
> obj = pkg_elem + 9;
> if (obj->type == ACPI_TYPE_STRING)
> strlcpy(lpi_state->desc, obj->string.pointer,
> @@ -1059,9 +1079,16 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle,
>
> if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
> lpi_state->enable_parent_state = 0;
> +
> + obj_get_generic_addr(pkg_elem + 7, &lpi_state->res_cntr);
> +
> + obj_get_generic_addr(pkg_elem + 8, &lpi_state->usage_cntr);
> }
>
> acpi_handle_debug(handle, "Found %d power states\n", state_idx);
> +
> + /* Set up LPI sysfs */
> + acpi_lpi_sysfs_init(handle, info);
> end:
> kfree(buffer.pointer);
> return ret;
> @@ -1173,6 +1200,10 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
> if (!acpi_has_method(handle, "_LPI"))
> return -EINVAL;
>
> + /* If we have already initialized just return */
> + if (pr->flags.has_lpi == 1)
> + return 0;
> +
> flat_state_cnt = 0;
> prev = &info[0];
> curr = &info[1];
> @@ -1484,8 +1515,336 @@ int acpi_processor_power_exit(struct acpi_processor *pr)
> acpi_processor_registered--;
> if (acpi_processor_registered == 0)
> cpuidle_unregister_driver(&acpi_idle_driver);
> +
> + acpi_lpi_sysfs_exit(pr);
> }
>
> pr->flags.power_setup_done = 0;
> return 0;
> }
> +
> +
> +/*
> + * LPI sysfs support
> + */
> +
> +struct acpi_lpi_attr {
> + struct attribute attr;
> + ssize_t (*show)(struct kobject *kobj, struct attribute *attr,
> + char *buf);
> + ssize_t (*store)(struct kobject *kobj, struct attribute *attr,
> + const char *c, ssize_t count);
> +};
> +
> +#define define_lpi_ro(_name) static struct acpi_lpi_attr _name = \
> + __ATTR(_name, 0444, show_##_name, NULL)
> +
> +#define to_acpi_lpi_sysfs_state(k) \
> + container_of(k, struct acpi_lpi_sysfs_state, kobj)
> +
> +#define to_acpi_lpi_state(k) \
> + (&(to_acpi_lpi_sysfs_state(k)->lpi_state))
> +
> +static ssize_t show_state_name(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> +
> + return scnprintf(buf, PAGE_SIZE, "%s\n", lpi->desc);
> +}
> +define_lpi_ro(state_name);
> +
> +static int acpi_lpi_get_residency(struct acpi_lpi_state *lpi, u64 *val)
> +{
> + struct acpi_generic_address *reg;
> +
> + if (!lpi)
> + return -EFAULT;
> +
> + reg = &lpi->res_cntr;
> +
> + /* Supporting only system memory */
> + if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY ||
> + !(lpi->flags & ACPI_LPI_STATE_FLAGS_ENABLED) ||
> + !reg->address || !lpi->res_cnt_freq)
> + return -EINVAL;
> +
> + if (ACPI_FAILURE(acpi_read(val, reg)))
> + return -EFAULT;
> +
> + *val = div_u64((*val * 1000000), lpi->res_cnt_freq);
> + return 0;
> +
> +}
> +
> +/* shows residency in us */
> +static ssize_t show_residency(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> + u64 val = 0;
> + int ret;
> +
> + ret = acpi_lpi_get_residency(lpi, &val);
> +
> + if (ret == -EINVAL)
> + return scnprintf(buf, PAGE_SIZE, "<unsupported>\n");
> +
> + if (ret)
> + return ret;
> +
> + return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
> +}
> +define_lpi_ro(residency);
> +
> +static int acpi_lpi_get_usage(struct acpi_lpi_state *lpi, u64 *val)
> +{
> + struct acpi_generic_address *reg;
> +
> + if (!lpi)
> + return -EFAULT;
> +
> + reg = &lpi->usage_cntr;
> +
> + /* Supporting only system memory now (FFH not supported) */
> + if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY ||
> + !(lpi->flags & ACPI_LPI_STATE_FLAGS_ENABLED) ||
> + !reg->address)
> + return -EINVAL;
> +
> + if (ACPI_FAILURE(acpi_read(val, reg)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> +static ssize_t show_usage(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> + u64 val = 0;
> + int ret;
> +
> + ret = acpi_lpi_get_usage(lpi, &val);
> +
> + if (ret == -EINVAL)
> + return scnprintf(buf, PAGE_SIZE, "<unsupported>\n");
> +
> + if (ret)
> + return ret;
> +
> + return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
> +}
> +define_lpi_ro(usage);
> +
> +static ssize_t show_min_residency(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> +
> + return scnprintf(buf, PAGE_SIZE, "%u\n", lpi->min_residency);
> +}
> +define_lpi_ro(min_residency);
> +
> +static ssize_t show_wakeup_latency(struct kobject *kobj, struct attribute *attr,
> + char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> +
> + return scnprintf(buf, PAGE_SIZE, "%u\n", lpi->wake_latency);
> +}
> +define_lpi_ro(wakeup_latency);
> +
> +static ssize_t show_state_index(struct kobject *kobj,
> + struct attribute *attr, char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> +
> + return scnprintf(buf, PAGE_SIZE, "%u\n", lpi->index);
> +}
> +define_lpi_ro(state_index);
> +
> +static ssize_t show_enabled_parent_state(struct kobject *kobj,
> + struct attribute *attr, char *buf)
> +{
> + struct acpi_lpi_state *lpi = to_acpi_lpi_state(kobj);
> +
> + return scnprintf(buf, PAGE_SIZE, "%u\n", lpi->enable_parent_state);
> +}
> +define_lpi_ro(enabled_parent_state);
> +
> +static struct attribute *acpi_lpi_state_attrs[] = {
> + &state_name.attr,
> + &min_residency.attr,
> + &wakeup_latency.attr,
> + &residency.attr,
> + &usage.attr,
> + &state_index.attr,
> + &enabled_parent_state.attr,
> + NULL
> +};
> +
> +static struct kobj_type lpi_state_ktype = {
> + .sysfs_ops = &kobj_sysfs_ops,
> + .default_attrs = acpi_lpi_state_attrs,
> +};
> +
> +static void acpi_lpi_sysfs_release(struct kobject *kobj)
> +{
> + struct acpi_lpi_sysfs_data *sysfs_data =
> + container_of(kobj, struct acpi_lpi_sysfs_data, kobj);
> +
> + kfree(sysfs_data->sysfs_states);
> + kfree(sysfs_data);
> +}
> +
> +static struct kobj_type lpi_device_ktype = {
> + .sysfs_ops = &kobj_sysfs_ops,
> + .release = acpi_lpi_sysfs_release,
> +};
> +
> +static int acpi_lpi_sysfs_get(struct acpi_lpi_sysfs_data *sysfs_data)
> +{
> + int i;
> +
> + if (!sysfs_data)
> + return -EFAULT;
> +
> + for (i = 0; i < sysfs_data->state_count; i++)
> + kobject_get(&sysfs_data->sysfs_states[i].kobj);
> +
> + kobject_get(&sysfs_data->kobj);
> +
> + return 0;
> +}
> +
> +static int acpi_lpi_sysfs_put(struct acpi_lpi_sysfs_data *sysfs_data)
> +{
> + int i;
> +
> + if (!sysfs_data)
> + return -EFAULT;
> +
> + for (i = 0; i < sysfs_data->state_count; i++)
> + kobject_put(&sysfs_data->sysfs_states[i].kobj);
> +
> + kobject_put(&sysfs_data->kobj);
> +
> + return 0;
> +}
> +
> +/*
> + * Given parsed LPI info creates sysfs entries to expose differnt LPI attributes
> + * stats for all the "enabled" states
> + */
> +static int acpi_lpi_sysfs_init(acpi_handle h,
> + struct acpi_lpi_states_array *info)
> +{
> + struct acpi_device *d;
> + struct acpi_lpi_sysfs_state *sysfs_state = NULL;
> + struct acpi_lpi_sysfs_data **lpi_sysfs_data;
> + struct acpi_lpi_sysfs_data *data = NULL;
> + int ret, i, j;
> +
> + if (!info)
> + return -EINVAL;
> +
> + ret = acpi_bus_get_device(h, &d);
> + if (ret)
> + return ret;
> +
> + if (!strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
> + lpi_sysfs_data = (struct acpi_lpi_sysfs_data **)&d->driver_data;
> + else {
> + struct acpi_processor *pr = acpi_driver_data(d);
> +
> + lpi_sysfs_data = &pr->power.lpi_sysfs_data;
> + }
> +
> + /* Already initialized, get a reference and return */
> + if (*lpi_sysfs_data) {
> + acpi_lpi_sysfs_get(*lpi_sysfs_data);
> + return 0;
> + }
> +
> + data = kzalloc(sizeof(struct acpi_lpi_sysfs_data), GFP_KERNEL);
> + if (!data) {
> + ret = -ENOMEM;
> + goto kfree_and_return;
> + }
> +
> + /* Count number of enabled states */
> + for (i = 0; i < info->size; i++)
> + if (info->entries[i].flags & ACPI_LPI_STATE_FLAGS_ENABLED)
> + data->state_count++;
> +
> + sysfs_state = kcalloc(data->state_count,
> + sizeof(struct acpi_lpi_sysfs_state), GFP_KERNEL);
> + if (!sysfs_state) {
> + ret = -ENOMEM;
> + goto kfree_and_return;
> + }
> +
> + ret = kobject_init_and_add(&data->kobj, &lpi_device_ktype, &d->dev.kobj,
> + "lpi");
> + if (ret)
> + goto kfree_and_return;
> +
> + *lpi_sysfs_data = data;
> + data->sysfs_states = sysfs_state;
> +
> + for (i = 0, j = 0; i < info->size; i++) {
> + if (!(info->entries[i].flags & ACPI_LPI_STATE_FLAGS_ENABLED))
> + continue;
> + sysfs_state = data->sysfs_states + j;
> + memcpy(&sysfs_state->lpi_state, info->entries + i,
> + sizeof(struct acpi_lpi_state));
> + ret = kobject_init_and_add(&sysfs_state->kobj, &lpi_state_ktype,
> + &data->kobj, "state%d", j);
> + if (ret)
> + break;
> + j++;
> + }
> +
> + if (ret) {
> + while (j > 0) {
> + j--;
> + sysfs_state = data->sysfs_states + i;
> + kobject_put(&sysfs_state->kobj);
> + }
> + kobject_put(&data->kobj);
> + } else
> + *lpi_sysfs_data = data;
> +
> + return ret;
> +
> +kfree_and_return:
> + kfree(data);
> + kfree(sysfs_state);
> + return ret;
> +}
> +
> +static int acpi_lpi_sysfs_exit(struct acpi_processor *pr)
> +{
> + acpi_handle handle, p_handle;
> + struct acpi_device *d = NULL;
> + acpi_status status;
> +
> + if (!pr)
> + return -ENODEV;
> +
> + handle = pr->handle;
> + acpi_lpi_sysfs_put(pr->power.lpi_sysfs_data);
> +
> + status = acpi_get_parent(handle, &p_handle);
> + while (ACPI_SUCCESS(status)) {
> + acpi_bus_get_device(p_handle, &d);
> + if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
> + break;
> +
> + acpi_lpi_sysfs_put((struct acpi_lpi_sysfs_data *)d->driver_data);
> + status = acpi_get_parent(handle, &p_handle);
> + }
> +
> + return 0;
> +}
> diff --git a/include/acpi/processor.h b/include/acpi/processor.h
> index c1ba00f..b99b84b 100644
> --- a/include/acpi/processor.h
> +++ b/include/acpi/processor.h
> @@ -79,6 +79,19 @@ struct acpi_lpi_state {
> u8 index;
> u8 entry_method;
> char desc[ACPI_CX_DESC_LEN];
> + struct acpi_generic_address res_cntr;
> + struct acpi_generic_address usage_cntr;
> +};
> +
> +struct acpi_lpi_sysfs_state {
> + struct acpi_lpi_state lpi_state;
> + struct kobject kobj;
> +};
> +
> +struct acpi_lpi_sysfs_data {
> + u8 state_count;
> + struct kobject kobj;
> + struct acpi_lpi_sysfs_state *sysfs_states;
> };
>
> struct acpi_processor_power {
> @@ -88,6 +101,7 @@ struct acpi_processor_power {
> struct acpi_lpi_state lpi_states[ACPI_PROCESSOR_MAX_POWER];
> };
> int timer_broadcast_on_state;
> + struct acpi_lpi_sysfs_data *lpi_sysfs_data;
> };
>
> /* Performance Management */
--
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