staging: gasket: Add performance scaling based on temperature

Perform periodic polling of apex temperature and scale down its frequency if temperature is above one of defined trip points. Added sysfs nodes to control related settings on per device basis. Added module parameters to set allow setting default value for all devices in system. Signed-off-by: Leonid Lobachev <leonidl@google.com> Change-Id: I5065282cba9f0888abd4086601bda89174f24705
2019-06-07 13:23:49 -07:00
parent 83ce758fc4
commit fbe01658e7
1 changed files with 200 additions and 3 deletions
--- a/apex_driver.c
+++ b/apex_driver.c
@@ -5,6 +5,7 @@
 * Copyright (C) 2018 Google, Inc.
 */

+#include <linux/atomic.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -17,6 +18,7 @@
 #include <linux/printk.h>
 #include <linux/sched.h>
 #include <linux/uaccess.h>
+#include <linux/workqueue.h>

 #include "apex.h"

@@ -62,6 +64,17 @@
 /* Wait 100 ms between checks. Total 12 sec wait maximum. */
 #define APEX_RESET_DELAY 100

+/* Interval between temperature polls, 0 disables polling */
+#define DEFAULT_APEX_TEMP_POLL_INTERVAL 0
+
+/* apex device private data */
+struct apex_dev {
+	struct gasket_dev *gasket_dev_ptr;
+	struct delayed_work check_temperature_work;
+	u32 adc_trip_points[3];
+	atomic_t temp_poll_interval;
+};
+
 /* Enumeration of the supported sysfs entries. */
 enum sysfs_attribute_type {
 	ATTR_KERNEL_HIB_PAGE_TABLE_SIZE,
@@ -72,6 +85,10 @@ enum sysfs_attribute_type {
 	ATTR_TEMP_WARN1_EN,
 	ATTR_TEMP_WARN2,
 	ATTR_TEMP_WARN2_EN,
+	ATTR_TEMP_TRIP0,
+	ATTR_TEMP_TRIP1,
+	ATTR_TEMP_TRIP2,
+	ATTR_TEMP_POLL_INTERVAL,
 };

 /*
@@ -234,7 +251,6 @@ static struct gasket_interrupt_desc apex_interrupts[] = {
 	},
 };

-
 /* Allows device to enter power save upon driver close(). */
 static int allow_power_save = 1;

@@ -253,6 +269,23 @@ module_param(allow_sw_clock_gating, int, 0644);
 module_param(allow_hw_clock_gating, int, 0644);
 module_param(bypass_top_level, int, 0644);

+/* Temperature points in milli C at which DFS is toggled */
+#define DEFAULT_TRIP_POINT0_TEMP 85000
+#define DEFAULT_TRIP_POINT1_TEMP 90000
+#define DEFAULT_TRIP_POINT2_TEMP 95000
+
+static int trip_point0_temp = DEFAULT_TRIP_POINT0_TEMP;
+static int trip_point1_temp = DEFAULT_TRIP_POINT1_TEMP;
+static int trip_point2_temp = DEFAULT_TRIP_POINT2_TEMP;
+
+module_param(trip_point0_temp, int, 0644);
+module_param(trip_point1_temp, int, 0644);
+module_param(trip_point2_temp, int, 0644);
+
+/* Temperature poll interval in ms */
+static int temp_poll_interval = DEFAULT_APEX_TEMP_POLL_INTERVAL;
+module_param(temp_poll_interval, int, 0644);
+
 /* Check the device status registers and return device status ALIVE or DEAD. */
 static int apex_get_status(struct gasket_dev *gasket_dev)
 {
@@ -589,6 +622,7 @@ static ssize_t sysfs_show(struct device *device, struct device_attribute *attr,
 	int ret;
 	unsigned value;
 	struct gasket_dev *gasket_dev;
+	struct apex_dev *apex_dev;
 	struct gasket_sysfs_attribute *gasket_attr;
 	enum sysfs_attribute_type type;

@@ -598,6 +632,13 @@ static ssize_t sysfs_show(struct device *device, struct device_attribute *attr,
 		return -ENODEV;
 	}

+	if (!gasket_dev->pci_dev ||
+	    !(apex_dev = pci_get_drvdata(gasket_dev->pci_dev))) {
+		dev_err(device, "Can't find apex_dev data\n");
+		gasket_sysfs_put_device_data(device, gasket_dev);
+		return -ENODEV;
+	}
+
 	gasket_attr = gasket_sysfs_get_attr(device, attr);
 	if (!gasket_attr) {
 		dev_err(device, "No Apex device sysfs attr data found\n");
@@ -650,6 +691,22 @@ static ssize_t sysfs_show(struct device *device, struct device_attribute *attr,
 					   APEX_BAR2_REG_OMC0_D8);
 		ret = scnprintf(buf, PAGE_SIZE, "%i\n", value >> 31);
 		break;
+	case ATTR_TEMP_TRIP0:
+		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
+				adc_to_millic(apex_dev->adc_trip_points[0]));
+		break;
+	case ATTR_TEMP_TRIP1:
+		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
+				adc_to_millic(apex_dev->adc_trip_points[1]));
+		break;
+	case ATTR_TEMP_TRIP2:
+		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
+				adc_to_millic(apex_dev->adc_trip_points[2]));
+		break;
+	case ATTR_TEMP_POLL_INTERVAL:
+		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
+				atomic_read(&apex_dev->temp_poll_interval));
+		break;
 	default:
 		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
 			attr->attr.name);
@@ -668,6 +725,7 @@ static ssize_t sysfs_store(struct device *device, struct device_attribute *attr,
 {
 	int ret = count, value;
 	struct gasket_dev *gasket_dev;
+	struct apex_dev *apex_dev;
 	struct gasket_sysfs_attribute *gasket_attr;
 	enum sysfs_attribute_type type;

@@ -680,6 +738,13 @@ static ssize_t sysfs_store(struct device *device, struct device_attribute *attr,
 		return -ENODEV;
 	}

+	if (!gasket_dev->pci_dev ||
+	    !(apex_dev = pci_get_drvdata(gasket_dev->pci_dev))) {
+		dev_err(device, "Can't find apex_dev data\n");
+		gasket_sysfs_put_device_data(device, gasket_dev);
+		return -ENODEV;
+	}
+
 	gasket_attr = gasket_sysfs_get_attr(device, attr);
 	if (!gasket_attr) {
 		dev_err(device, "No Apex device sysfs attr data found\n");
@@ -713,6 +778,34 @@ static ssize_t sysfs_store(struct device *device, struct device_attribute *attr,
 					    APEX_BAR2_REG_OMC0_D8, value, 1,
 					    31);
 		break;
+	case ATTR_TEMP_TRIP0:
+		value = millic_to_adc(value);
+		/* Note: that adc values should be in descending order */
+		if (value >= apex_dev->adc_trip_points[1]) {
+			apex_dev->adc_trip_points[0] = value;
+		} else ret = -EINVAL;
+		break;
+	case ATTR_TEMP_TRIP1:
+		value = millic_to_adc(value);
+		if (value <= apex_dev->adc_trip_points[0] &&
+		    value >= apex_dev->adc_trip_points[2]) {
+			apex_dev->adc_trip_points[1] = value;
+		} else ret = -EINVAL;
+		break;
+	case ATTR_TEMP_TRIP2:
+		value = millic_to_adc(value);
+		if (value <= apex_dev->adc_trip_points[1]) {
+			apex_dev->adc_trip_points[2] = value;
+		} else ret = -EINVAL;
+		break;
+	case ATTR_TEMP_POLL_INTERVAL:
+		cancel_delayed_work_sync(&apex_dev->check_temperature_work);
+		atomic_set(&apex_dev->temp_poll_interval, value);
+		if (value > 0)
+			schedule_delayed_work(&apex_dev->check_temperature_work,
+					      msecs_to_jiffies(value));
+
+		break;
 	default:
 		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
 			attr->attr.name);
@@ -739,9 +832,84 @@ static struct gasket_sysfs_attribute apex_sysfs_attrs[] = {
 	GASKET_SYSFS_RW(temp_warn2, sysfs_show, sysfs_store, ATTR_TEMP_WARN2),
 	GASKET_SYSFS_RW(temp_warn2_en, sysfs_show, sysfs_store,
 			ATTR_TEMP_WARN2_EN),
+	GASKET_SYSFS_RW(trip_point0_temp, sysfs_show, sysfs_store,
+			ATTR_TEMP_TRIP0),
+	GASKET_SYSFS_RW(trip_point1_temp, sysfs_show, sysfs_store,
+			ATTR_TEMP_TRIP1),
+	GASKET_SYSFS_RW(trip_point2_temp, sysfs_show, sysfs_store,
+			ATTR_TEMP_TRIP2),
+	GASKET_SYSFS_RW(temp_poll_interval, sysfs_show, sysfs_store,
+			ATTR_TEMP_POLL_INTERVAL),
 	GASKET_END_OF_ATTR_ARRAY
 };

+static void apply_module_params(struct apex_dev *apex_dev) {
+	kernel_param_lock(THIS_MODULE);
+
+	/* use defaults if trip point temperatures are not in ascending order */
+	if (trip_point0_temp > trip_point1_temp ||
+	    trip_point1_temp > trip_point2_temp) {
+		dev_warn(apex_dev->gasket_dev_ptr->dev,
+			 "Invalid module parameters for temperature trip points"
+			 ", using defaults\n");
+		trip_point0_temp = DEFAULT_TRIP_POINT0_TEMP;
+		trip_point1_temp = DEFAULT_TRIP_POINT1_TEMP;
+		trip_point2_temp = DEFAULT_TRIP_POINT2_TEMP;
+	}
+
+	apex_dev->adc_trip_points[0] = millic_to_adc(trip_point0_temp);
+	apex_dev->adc_trip_points[1] = millic_to_adc(trip_point1_temp);
+	apex_dev->adc_trip_points[2] = millic_to_adc(trip_point2_temp);
+	atomic_set(&apex_dev->temp_poll_interval, temp_poll_interval);
+
+	kernel_param_unlock(THIS_MODULE);
+}
+
+static void check_temperature_work_handler(struct work_struct *work) {
+	int i;
+	u32 adc_temp, clk_div, tmp;
+	const u32 mask = ((1 << 2) - 1) << 28;
+	struct apex_dev *apex_dev =
+		container_of(work, struct apex_dev,
+			     check_temperature_work.work);
+	struct gasket_dev *gasket_dev = apex_dev->gasket_dev_ptr;
+
+	mutex_lock(&gasket_dev->mutex);
+
+	/* Read current temperature */
+	adc_temp = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
+				      APEX_BAR2_REG_OMC0_DC);
+	adc_temp = (adc_temp >> 16) & ((1 << 10) - 1);
+
+	/* Find closest trip point
+	   Note: that adc values are in descending order */
+	for (i = ARRAY_SIZE(apex_dev->adc_trip_points) - 1; i >= 0; --i) {
+		if (adc_temp <= apex_dev->adc_trip_points[i])
+			break;
+	}
+	/* Compute divider value and shift into appropriate bit location */
+	clk_div = (i + 1) << 28;
+
+	/* Modify gcb clk divider if it's different from current one */
+	tmp = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
+				 APEX_BAR2_REG_SCU_3);
+	if (clk_div != (tmp & mask)) {
+		tmp = (tmp & ~mask) | clk_div;
+		gasket_dev_write_32(gasket_dev, tmp, APEX_BAR_INDEX,
+				    APEX_BAR2_REG_SCU_3);
+		dev_warn(gasket_dev->dev,
+			 "Apex performance %sthrottled due to temperature\n",
+			 i == -1 ? "not " : "");
+	}
+
+	mutex_unlock(&gasket_dev->mutex);
+
+	int temp_poll_interval = atomic_read(&apex_dev->temp_poll_interval);
+	if (temp_poll_interval > 0)
+		schedule_delayed_work(&apex_dev->check_temperature_work,
+				      msecs_to_jiffies(temp_poll_interval));
+}
+
 /* On device open, perform a core reinit reset. */
 static int apex_device_open_cb(struct gasket_dev *gasket_dev)
 {
@@ -766,6 +934,7 @@ static int apex_pci_probe(struct pci_dev *pci_dev,
 	ulong page_table_ready, msix_table_ready;
 	int retries = 0;
 	struct gasket_dev *gasket_dev;
+	struct apex_dev *apex_dev;

 	ret = pci_enable_device(pci_dev);
 #ifdef MODULE
@@ -789,7 +958,18 @@ static int apex_pci_probe(struct pci_dev *pci_dev,
 		return ret;
 	}

-	pci_set_drvdata(pci_dev, gasket_dev);
+	apex_dev = kzalloc(sizeof(*apex_dev), GFP_KERNEL);
+	if (!apex_dev) {
+		dev_err(&pci_dev->dev, "no memory for device\n");
+		ret = -ENOMEM;
+		goto remove_device;
+ 	}
+
+	INIT_DELAYED_WORK(&apex_dev->check_temperature_work,
+			  check_temperature_work_handler);
+	apex_dev->gasket_dev_ptr = gasket_dev;
+	apply_module_params(apex_dev);
+	pci_set_drvdata(pci_dev, apex_dev);
 	apex_reset(gasket_dev);

 	while (retries < APEX_RESET_RETRY) {
@@ -843,19 +1023,36 @@ static int apex_pci_probe(struct pci_dev *pci_dev,
 	if (allow_power_save)
 		apex_enter_reset(gasket_dev);

+	/* Enable thermal polling */
+	int temp_poll_interval = atomic_read(&apex_dev->temp_poll_interval);
+	if (temp_poll_interval > 0)
+		schedule_delayed_work(&apex_dev->check_temperature_work,
+				      msecs_to_jiffies(temp_poll_interval));
 	return 0;

 remove_device:
 	gasket_pci_remove_device(pci_dev);
 	pci_disable_device(pci_dev);
+	kfree(apex_dev);
 	return ret;
 }

 static void apex_pci_remove(struct pci_dev *pci_dev)
 {
-	struct gasket_dev *gasket_dev = pci_get_drvdata(pci_dev);
+	struct apex_dev *apex_dev = pci_get_drvdata(pci_dev);
+	struct gasket_dev *gasket_dev;
+
+	if (!apex_dev) {
+		dev_err(&pci_dev->dev, "NULL apex_dev\n");
+		goto remove_device;
+	}
+	gasket_dev = apex_dev->gasket_dev_ptr;
+
+	cancel_delayed_work_sync(&apex_dev->check_temperature_work);
+	kfree(apex_dev);

 	gasket_disable_device(gasket_dev);
+remove_device:
 	gasket_pci_remove_device(pci_dev);
 	pci_disable_device(pci_dev);
 }