2023-04-20 17:38:04

by Konrad Dybcio

[permalink] [raw]
Subject: [PATCH v6 0/2] Introduce RPM Master stats

v5 -> v6:
- pick up tags
- fix 'decisons' -> 'decisions' typo

v5: https://lore.kernel.org/r/[email protected]

v4 -> v5:
- pick up tags
- uintXY_t -> uXY
- driver.name = "rpm_master_stats" -> "qcom_rpm_master_stats"
- use dev_err_probe for debugfs file creation fail
- use PTR_ERR(dent) intead of -EINVAL for debugfs file creation fail

v4: https://lore.kernel.org/r/[email protected]

v3 -> v4:
- Use "data" instead of "d" for naming local struct master_stats_data *
- Add "qcom_" prefix in the debugfs path
- Add "Qualcomm" prefix in MODULE_NAME
- Make the struct __packed__ to avoid padding surprises
(even though it looks like there shouldn't be any, by eye)
- use IS_ERR for checking debugfs_create_file return value instead of
nullchecking, that apparently changed..
- Use -ENODEV instead of -EINVAL when a MSG RAM handle is not found
- Add missing of_node_put() after of_parse_phandle()

- Vastly improve the documentation bit

v3: https://lore.kernel.org/r/[email protected]

v2 -> v3:
- rename rpm-master-stats.yaml to qcom,rpm-master-stats.yaml

v2: https://lore.kernel.org/r/[email protected]

v1 -> v2:
- Drop the `-` in /properties/compatible to make our entry be of the
correct type [1/2]
- Change %s to %d for printing out the iterator [2/2]

v1: https://lore.kernel.org/r/[email protected]

The RPM MSG ram includes per-subsystem low-power mode entry/exit/
residence/etc. statistics which are very useful for trying to debug
what I'd call "SoC insomnia", or IOW the plaftorm refusing to drop
the voltage rails to a minimum and gate the non-critical clocks.

This series adds a very short and simple driver to query that data
and expose it through debugfs.

The base used for writing this driver is:
https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.9.14.r1/drivers/soc/qcom/rpm_master_stat.c

Signed-off-by: Konrad Dybcio <[email protected]>
---
Konrad Dybcio (2):
dt-bindings: soc: qcom: Add RPM Master stats
soc: qcom: Introduce RPM master stats driver

.../bindings/soc/qcom/qcom,rpm-master-stats.yaml | 69 +++++++++
drivers/soc/qcom/Kconfig | 11 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/rpm_master_stats.c | 163 +++++++++++++++++++++
4 files changed, 244 insertions(+)
---
base-commit: 67d5d9f013d6c3829383c08162939cabff14fccc
change-id: 20230405-topic-master_stats-ba201a9af93d

Best regards,
--
Konrad Dybcio <[email protected]>


2023-04-20 17:38:18

by Konrad Dybcio

[permalink] [raw]
Subject: [PATCH v6 1/2] dt-bindings: soc: qcom: Add RPM Master stats

The RPM MSG RAM contains per-RPM-master (e.g. APPS, ADSP etc.) sleep
statistics. They let one assess which core is actively preventing the
system from entering a true low-power mode.

Reviewed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Konrad Dybcio <[email protected]>
---
.../bindings/soc/qcom/qcom,rpm-master-stats.yaml | 69 ++++++++++++++++++++++
1 file changed, 69 insertions(+)

diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml
new file mode 100644
index 000000000000..031800985b5e
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/qcom,rpm-master-stats.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Technologies, Inc. (QTI) RPM Master Stats
+
+maintainers:
+ - Konrad Dybcio <[email protected]>
+
+description: |
+ The Qualcomm RPM (Resource Power Manager) architecture includes a concept
+ of "RPM Masters". They can be thought of as "the local gang leaders", usually
+ spanning a single subsystem (e.g. APSS, ADSP, CDSP). All of the RPM decisions
+ (particularly around entering hardware-driven low power modes: XO shutdown
+ and total system-wide power collapse) are first made at Master-level, and
+ only then aggregated for the entire system.
+
+ The Master Stats provide a few useful bits that can be used to assess whether
+ our device has entered the desired low-power mode, how long it took to do so,
+ the duration of that residence, how long it took to come back online,
+ how many times a given sleep state was entered and which cores are actively
+ voting for staying awake.
+
+ This scheme has been used on various SoCs in the 2013-2023 era, with some
+ newer or higher-end designs providing this information through an SMEM query.
+
+properties:
+ compatible:
+ const: qcom,rpm-master-stats
+
+ qcom,rpm-msg-ram:
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+ description: Phandle to an RPM MSG RAM slice containing the master stats
+ minItems: 1
+ maxItems: 5
+
+ qcom,master-names:
+ $ref: /schemas/types.yaml#/definitions/string-array
+ description:
+ The name of the RPM Master which owns the MSG RAM slice where this
+ instance of Master Stats resides
+ minItems: 1
+ maxItems: 5
+
+required:
+ - compatible
+ - qcom,rpm-msg-ram
+ - qcom,master-names
+
+additionalProperties: false
+
+examples:
+ - |
+ stats {
+ compatible = "qcom,rpm-master-stats";
+ qcom,rpm-msg-ram = <&apss_master_stats>,
+ <&mpss_master_stats>,
+ <&adsp_master_stats>,
+ <&cdsp_master_stats>,
+ <&tz_master_stats>;
+ qcom,master-names = "APSS",
+ "MPSS",
+ "ADSP",
+ "CDSP",
+ "TZ";
+ };
+...

--
2.40.0

2023-04-20 17:38:33

by Konrad Dybcio

[permalink] [raw]
Subject: [PATCH v6 2/2] soc: qcom: Introduce RPM master stats driver

Introduce a driver to query and expose detailed, per-subsystem (as opposed
to the existing qcom_stats driver which exposes SoC-wide data) about low
power mode states of a given RPM master. That includes the APSS (ARM),
MPSS (modem) and other remote cores, depending on the platform
configuration.

This is a vastly cleaned up and restructured version of a similar
driver found in msm-5.4.

Reviewed-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Konrad Dybcio <[email protected]>
---
drivers/soc/qcom/Kconfig | 11 +++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/rpm_master_stats.c | 163 ++++++++++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index a491718f8064..e597799e8121 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -135,6 +135,17 @@ config QCOM_RMTFS_MEM

Say y here if you intend to boot the modem remoteproc.

+config QCOM_RPM_MASTER_STATS
+ tristate "Qualcomm RPM Master stats"
+ depends on ARCH_QCOM || COMPILE_TEST
+ help
+ The RPM Master sleep stats driver provides detailed per-subsystem
+ sleep/wake data, read from the RPM message RAM. It can be used to
+ assess whether all the low-power modes available are entered as
+ expected or to check which part of the SoC prevents it from sleeping.
+
+ Say y here if you intend to debug or monitor platform sleep.
+
config QCOM_RPMH
tristate "Qualcomm RPM-Hardened (RPMH) Communication"
depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 0f43a88b4894..7349371fdea1 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_QCOM_QMI_HELPERS) += qmi_helpers.o
qmi_helpers-y += qmi_encdec.o qmi_interface.o
obj-$(CONFIG_QCOM_RAMP_CTRL) += ramp_controller.o
obj-$(CONFIG_QCOM_RMTFS_MEM) += rmtfs_mem.o
+obj-$(CONFIG_QCOM_RPM_MASTER_STATS) += rpm_master_stats.o
obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o
qcom_rpmh-y += rpmh-rsc.o
qcom_rpmh-y += rpmh.o
diff --git a/drivers/soc/qcom/rpm_master_stats.c b/drivers/soc/qcom/rpm_master_stats.c
new file mode 100644
index 000000000000..6dd98b9f7129
--- /dev/null
+++ b/drivers/soc/qcom/rpm_master_stats.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023, Linaro Limited
+ *
+ * This driver supports what is known as "Master Stats v2" in Qualcomm
+ * downstream kernel terms, which seems to be the only version which has
+ * ever shipped, all the way from 2013 to 2023.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+struct master_stats_data {
+ void __iomem *base;
+ const char *label;
+};
+
+struct rpm_master_stats {
+ u32 active_cores;
+ u32 num_shutdowns;
+ u64 shutdown_req;
+ u64 wakeup_idx;
+ u64 bringup_req;
+ u64 bringup_ack;
+ u32 wakeup_reason; /* 0 = "rude wakeup", 1 = scheduled wakeup */
+ u32 last_sleep_trans_dur;
+ u32 last_wake_trans_dur;
+
+ /* Per-subsystem (*not necessarily* SoC-wide) XO shutdown stats */
+ u32 xo_count;
+ u64 xo_last_enter;
+ u64 last_exit;
+ u64 xo_total_dur;
+} __packed;
+
+static int master_stats_show(struct seq_file *s, void *unused)
+{
+ struct master_stats_data *data = s->private;
+ struct rpm_master_stats stat;
+
+ memcpy_fromio(&stat, data->base, sizeof(stat));
+
+ seq_printf(s, "%s:\n", data->label);
+
+ seq_printf(s, "\tLast shutdown @ %llu\n", stat.shutdown_req);
+ seq_printf(s, "\tLast bringup req @ %llu\n", stat.bringup_req);
+ seq_printf(s, "\tLast bringup ack @ %llu\n", stat.bringup_ack);
+ seq_printf(s, "\tLast wakeup idx: %llu\n", stat.wakeup_idx);
+ seq_printf(s, "\tLast XO shutdown enter @ %llu\n", stat.xo_last_enter);
+ seq_printf(s, "\tLast XO shutdown exit @ %llu\n", stat.last_exit);
+ seq_printf(s, "\tXO total duration: %llu\n", stat.xo_total_dur);
+ seq_printf(s, "\tLast sleep transition duration: %u\n", stat.last_sleep_trans_dur);
+ seq_printf(s, "\tLast wake transition duration: %u\n", stat.last_wake_trans_dur);
+ seq_printf(s, "\tXO shutdown count: %u\n", stat.xo_count);
+ seq_printf(s, "\tWakeup reason: 0x%x\n", stat.wakeup_reason);
+ seq_printf(s, "\tShutdown count: %u\n", stat.num_shutdowns);
+ seq_printf(s, "\tActive cores bitmask: 0x%x\n", stat.active_cores);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(master_stats);
+
+static int master_stats_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct master_stats_data *data;
+ struct device_node *msgram_np;
+ struct dentry *dent, *root;
+ struct resource res;
+ int count, i, ret;
+
+ count = of_property_count_strings(dev->of_node, "qcom,master-names");
+ if (count < 0)
+ return count;
+
+ data = devm_kzalloc(dev, count * sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ root = debugfs_create_dir("qcom_rpm_master_stats", NULL);
+ platform_set_drvdata(pdev, root);
+
+ for (i = 0; i < count; i++) {
+ msgram_np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", i);
+ if (!msgram_np) {
+ debugfs_remove_recursive(root);
+ return dev_err_probe(dev, -ENODEV,
+ "Couldn't parse MSG RAM phandle idx %d", i);
+ }
+
+ /*
+ * Purposefully skip devm_platform helpers as we're using a
+ * shared resource.
+ */
+ ret = of_address_to_resource(msgram_np, 0, &res);
+ of_node_put(msgram_np);
+ if (ret < 0) {
+ debugfs_remove_recursive(root);
+ return ret;
+ }
+
+ data[i].base = devm_ioremap(dev, res.start, resource_size(&res));
+ if (IS_ERR(data[i].base)) {
+ debugfs_remove_recursive(root);
+ return dev_err_probe(dev, -EINVAL,
+ "Could not map the MSG RAM slice idx %d!\n", i);
+ }
+
+ ret = of_property_read_string_index(dev->of_node, "qcom,master-names", i,
+ &data[i].label);
+ if (ret < 0) {
+ debugfs_remove_recursive(root);
+ return dev_err_probe(dev, ret,
+ "Could not read name idx %d!\n", i);
+ }
+
+ /*
+ * Generally it's not advised to fail on debugfs errors, but this
+ * driver's only job is exposing data therein.
+ */
+ dent = debugfs_create_file(data[i].label, 0444, root,
+ &data[i], &master_stats_fops);
+ if (IS_ERR(dent)) {
+ debugfs_remove_recursive(root);
+ return dev_err_probe(dev, PTR_ERR(dent),
+ "Failed to create debugfs file %s!\n", data[i].label);
+ }
+ }
+
+ device_set_pm_not_required(dev);
+
+ return 0;
+}
+
+static void master_stats_remove(struct platform_device *pdev)
+{
+ struct dentry *root = platform_get_drvdata(pdev);
+
+ debugfs_remove_recursive(root);
+}
+
+static const struct of_device_id rpm_master_table[] = {
+ { .compatible = "qcom,rpm-master-stats" },
+ { },
+};
+
+static struct platform_driver master_stats_driver = {
+ .probe = master_stats_probe,
+ .remove_new = master_stats_remove,
+ .driver = {
+ .name = "qcom_rpm_master_stats",
+ .of_match_table = rpm_master_table,
+ },
+};
+module_platform_driver(master_stats_driver);
+
+MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
+MODULE_LICENSE("GPL");

--
2.40.0

2023-05-25 05:43:18

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v6 0/2] Introduce RPM Master stats

On Thu, 20 Apr 2023 19:36:16 +0200, Konrad Dybcio wrote:
> v5 -> v6:
> - pick up tags
> - fix 'decisons' -> 'decisions' typo
>
> v5: https://lore.kernel.org/r/[email protected]
>
> v4 -> v5:
> - pick up tags
> - uintXY_t -> uXY
> - driver.name = "rpm_master_stats" -> "qcom_rpm_master_stats"
> - use dev_err_probe for debugfs file creation fail
> - use PTR_ERR(dent) intead of -EINVAL for debugfs file creation fail
>
> [...]

Applied, thanks!

[1/2] dt-bindings: soc: qcom: Add RPM Master stats
commit: 0be4392435a6a0e16b3eb56a8815ebdbcd44e1a7
[2/2] soc: qcom: Introduce RPM master stats driver
commit: a77b2a0b12801a232226d227636236ed89b77043

Best regards,
--
Bjorn Andersson <[email protected]>