qualcomm-linux · LXQUALCOMM · Sep 16, 2026 · Sep 16, 2026
diff --git a/arch/arm64/boot/dts/qcom/hamoa.dtsi b/arch/arm64/boot/dts/qcom/hamoa.dtsi
@@ -362,6 +362,10 @@
 				reg = <0x13>;
 				#power-domain-cells = <1>;
 			};
+
+			scmi_vendor: protocol@80 {
+				reg = <0x80>;
+			};
 		};
 	};
 

diff --git a/arch/arm64/configs/qcom.config b/arch/arm64/configs/qcom.config
@@ -54,6 +54,7 @@ CONFIG_PROC_EVENTS=y
 CONFIG_PTP_QCOM_CLOCK_TSC=m
 CONFIG_QCA808X_PHY=m
 CONFIG_QCOM_QMI_COOLING=y
+CONFIG_QCOM_SCMI_GENERIC_EXT=y
 CONFIG_REMOTEPROC_THERMAL=y
 CONFIG_SCHED_CLASS_EXT=y
 CONFIG_SCHED_DEBUG=y
@@ -122,6 +123,9 @@ CONFIG_SCSI_SMARTPQI=m
 # Support performance profiling
 CONFIG_FTRACE=y
 CONFIG_FUNCTION_TRACER=y
+# QCOM SCMI memlat bus scaling
+CONFIG_DEVFREQ_GOV_REMOTE=y
+CONFIG_SCMI_QCOM_MEMLAT_DEVFREQ=m
 # Kubernetes support
 CONFIG_CFS_BANDWIDTH=y
 CONFIG_CGROUP_FAVOR_DYNMODS=y

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
@@ -56,6 +56,14 @@ config DEVFREQ_GOV_POWERSAVE
 	  the DEVFREQ framework returns the lowest frequency available
 	  at any time.
 
+config DEVFREQ_GOV_REMOTE
+	tristate "Remote"
+	help
+	  A simple governor to track the frequency of devices whose
+	  dvfs control lies outside the kernel. This governor acts
+	  as an observer and provides for ways to track frequency and
+	  set/get information related to the remote dvfs device.
+
 config DEVFREQ_GOV_USERSPACE
 	tristate "Userspace"
 	help
@@ -161,6 +169,19 @@ config ARM_SUN8I_A33_MBUS_DEVFREQ
 	  This adds the DEVFREQ driver for the MBUS controller in some
 	  Allwinner sun8i (A33 through H3) and sun50i (A64 and H5) SoCs.
 
+config SCMI_QCOM_MEMLAT_DEVFREQ
+	tristate "Qualcomm Technologies Inc. SCMI client driver"
+	depends on QCOM_SCMI_GENERIC_EXT || COMPILE_TEST
+	select DEVFREQ_GOV_REMOTE
+	help
+	  This driver uses the MEMLAT (memory latency) algorithm string
+	  hosted on QCOM SCMI Vendor Protocol to detect memory latency
+	  workloads and control frequency/level of the various memory
+	  buses (DDR/LLCC/DDR_QOS).
+
+	  This driver defines/documents the parameter IDs used while configuring
+	  the memory buses.
+
 source "drivers/devfreq/event/Kconfig"
 
 endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_PM_DEVFREQ_EVENT)	+= devfreq-event.o
 obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)	+= governor_simpleondemand.o
 obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE)	+= governor_performance.o
 obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
+obj-$(CONFIG_DEVFREQ_GOV_REMOTE)	+= governor_remote.o
 obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)	+= governor_passive.o
 
@@ -16,6 +17,7 @@ obj-$(CONFIG_ARM_MEDIATEK_CCI_DEVFREQ)	+= mtk-cci-devfreq.o
 obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ)	+= rk3399_dmc.o
 obj-$(CONFIG_ARM_SUN8I_A33_MBUS_DEVFREQ)	+= sun8i-a33-mbus.o
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra30-devfreq.o
+obj-$(CONFIG_SCMI_QCOM_MEMLAT_DEVFREQ)	+= scmi-qcom-memlat-devfreq.o
 
 # DEVFREQ Event Drivers
 obj-$(CONFIG_PM_DEVFREQ_EVENT)		+= event/
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
@@ -20,6 +20,7 @@
 #include <linux/stat.h>
 #include <linux/pm_opp.h>
 #include <linux/devfreq.h>
+#include <linux/devfreq-governor.h>
 #include <linux/workqueue.h>
 #include <linux/platform_device.h>
 #include <linux/list.h>
@@ -28,7 +29,6 @@
 #include <linux/of.h>
 #include <linux/pm_qos.h>
 #include <linux/units.h>
-#include "governor.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/devfreq.h>
@@ -348,6 +348,10 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	unsigned long cur_freq;
 	int err = 0;
 
+	/* Frequency already updated, update trans-stat info */
+	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, TRACK_REMOTE))
+		goto update_status;
+
 	if (devfreq->profile->get_cur_freq)
 		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
 	else
@@ -375,6 +379,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	freqs.new = new_freq;
 	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
 
+update_status:
 	if (devfreq_update_status(devfreq, new_freq))
 		dev_warn(&devfreq->dev,
 			 "Couldn't update frequency transition information.\n");
@@ -1568,6 +1573,10 @@ static ssize_t target_freq_show(struct device *dev,
 {
 	struct devfreq *df = to_devfreq(dev);
 
+	if (!df->profile || !df->governor ||
+	    !IS_SUPPORTED_ATTR(df->governor->attrs, TARGET_FREQ))
+		return -EINVAL;
+
 	return sprintf(buf, "%lu\n", df->previous_freq);
 }
 static DEVICE_ATTR_RO(target_freq);

diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
@@ -1,127 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * governor.h - internal header for devfreq governors.
- *
- * Copyright (C) 2011 Samsung Electronics
- *	MyungJoo Ham <myungjoo.ham@samsung.com>
- *
- * This header is for devfreq governors in drivers/devfreq/
+ * Compatibility shim: governor.h was moved to include/linux/devfreq-governor.h
+ * in kernel 6.19 (commit 447c4e8338db). This file exists to support out-of-tree
+ * modules (e.g. kgsl) that still reference the old location on 6.18.y kernels.
  */
-
-#ifndef _GOVERNOR_H
-#define _GOVERNOR_H
-
-#include <linux/devfreq.h>
-
-#define DEVFREQ_NAME_LEN			16
-
-#define to_devfreq(DEV)	container_of((DEV), struct devfreq, dev)
-
-/* Devfreq events */
-#define DEVFREQ_GOV_START			0x1
-#define DEVFREQ_GOV_STOP			0x2
-#define DEVFREQ_GOV_UPDATE_INTERVAL		0x3
-#define DEVFREQ_GOV_SUSPEND			0x4
-#define DEVFREQ_GOV_RESUME			0x5
-
-#define DEVFREQ_MIN_FREQ			0
-#define DEVFREQ_MAX_FREQ			ULONG_MAX
-
-/*
- * Definition of the governor feature flags
- * - DEVFREQ_GOV_FLAG_IMMUTABLE
- *   : This governor is never changeable to other governors.
- * - DEVFREQ_GOV_FLAG_IRQ_DRIVEN
- *   : The devfreq won't schedule the work for this governor.
- */
-#define DEVFREQ_GOV_FLAG_IMMUTABLE			BIT(0)
-#define DEVFREQ_GOV_FLAG_IRQ_DRIVEN			BIT(1)
-
-/*
- * Definition of governor attribute flags except for common sysfs attributes
- * - DEVFREQ_GOV_ATTR_POLLING_INTERVAL
- *   : Indicate polling_interval sysfs attribute
- * - DEVFREQ_GOV_ATTR_TIMER
- *   : Indicate timer sysfs attribute
- */
-#define DEVFREQ_GOV_ATTR_POLLING_INTERVAL		BIT(0)
-#define DEVFREQ_GOV_ATTR_TIMER				BIT(1)
-
-/**
- * struct devfreq_cpu_data - Hold the per-cpu data
- * @node:	list node
- * @dev:	reference to cpu device.
- * @first_cpu:	the cpumask of the first cpu of a policy.
- * @opp_table:	reference to cpu opp table.
- * @cur_freq:	the current frequency of the cpu.
- * @min_freq:	the min frequency of the cpu.
- * @max_freq:	the max frequency of the cpu.
- *
- * This structure stores the required cpu_data of a cpu.
- * This is auto-populated by the governor.
- */
-struct devfreq_cpu_data {
-	struct list_head node;
-
-	struct device *dev;
-	unsigned int first_cpu;
-
-	struct opp_table *opp_table;
-	unsigned int cur_freq;
-	unsigned int min_freq;
-	unsigned int max_freq;
-};
-
-/**
- * struct devfreq_governor - Devfreq policy governor
- * @node:		list node - contains registered devfreq governors
- * @name:		Governor's name
- * @attrs:		Governor's sysfs attribute flags
- * @flags:		Governor's feature flags
- * @get_target_freq:	Returns desired operating frequency for the device.
- *			Basically, get_target_freq will run
- *			devfreq_dev_profile.get_dev_status() to get the
- *			status of the device (load = busy_time / total_time).
- * @event_handler:      Callback for devfreq core framework to notify events
- *                      to governors. Events include per device governor
- *                      init and exit, opp changes out of devfreq, suspend
- *                      and resume of per device devfreq during device idle.
- *
- * Note that the callbacks are called with devfreq->lock locked by devfreq.
- */
-struct devfreq_governor {
-	struct list_head node;
-
-	const char name[DEVFREQ_NAME_LEN];
-	const u64 attrs;
-	const u64 flags;
-	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
-	int (*event_handler)(struct devfreq *devfreq,
-				unsigned int event, void *data);
-};
-
-void devfreq_monitor_start(struct devfreq *devfreq);
-void devfreq_monitor_stop(struct devfreq *devfreq);
-void devfreq_monitor_suspend(struct devfreq *devfreq);
-void devfreq_monitor_resume(struct devfreq *devfreq);
-void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay);
-
-int devfreq_add_governor(struct devfreq_governor *governor);
-int devfreq_remove_governor(struct devfreq_governor *governor);
-
-int devm_devfreq_add_governor(struct device *dev,
-			      struct devfreq_governor *governor);
-
-int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
-int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
-void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq,
-			    unsigned long *max_freq);
-
-static inline int devfreq_update_stats(struct devfreq *df)
-{
-	if (!df->profile->get_dev_status)
-		return -EINVAL;
-
-	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
-}
-#endif /* _GOVERNOR_H */
+#include <linux/devfreq-governor.h>
diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
@@ -14,8 +14,33 @@
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/devfreq.h>
+#include <linux/devfreq-governor.h>
 #include <linux/units.h>
-#include "governor.h"
+
+/**
+ * struct devfreq_cpu_data - Hold the per-cpu data
+ * @node:	list node
+ * @dev:	reference to cpu device.
+ * @first_cpu:	the cpumask of the first cpu of a policy.
+ * @opp_table:	reference to cpu opp table.
+ * @cur_freq:	the current frequency of the cpu.
+ * @min_freq:	the min frequency of the cpu.
+ * @max_freq:	the max frequency of the cpu.
+ *
+ * This structure stores the required cpu_data of a cpu.
+ * This is auto-populated by the governor.
+ */
+struct devfreq_cpu_data {
+	struct list_head node;
+
+	struct device *dev;
+	unsigned int first_cpu;
+
+	struct opp_table *opp_table;
+	unsigned int cur_freq;
+	unsigned int min_freq;
+	unsigned int max_freq;
+};
 
 static struct devfreq_cpu_data *
 get_parent_cpu_data(struct devfreq_passive_data *p_data,
@@ -424,6 +449,7 @@ static int devfreq_passive_event_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_passive = {
 	.name = DEVFREQ_GOV_PASSIVE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.flags = DEVFREQ_GOV_FLAG_IMMUTABLE,
 	.get_target_freq = devfreq_passive_get_target_freq,
 	.event_handler = devfreq_passive_event_handler,

diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
@@ -7,8 +7,8 @@
  */
 
 #include <linux/devfreq.h>
+#include <linux/devfreq-governor.h>
 #include <linux/module.h>
-#include "governor.h"
 
 static int devfreq_performance_func(struct devfreq *df,
 				    unsigned long *freq)
@@ -37,6 +37,7 @@ static int devfreq_performance_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_performance = {
 	.name = DEVFREQ_GOV_PERFORMANCE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.get_target_freq = devfreq_performance_func,
 	.event_handler = devfreq_performance_handler,
 };

diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
@@ -7,8 +7,8 @@
  */
 
 #include <linux/devfreq.h>
+#include <linux/devfreq-governor.h>
 #include <linux/module.h>
-#include "governor.h"
 
 static int devfreq_powersave_func(struct devfreq *df,
 				  unsigned long *freq)
@@ -37,6 +37,7 @@ static int devfreq_powersave_handler(struct devfreq *devfreq,
 
 static struct devfreq_governor devfreq_powersave = {
 	.name = DEVFREQ_GOV_POWERSAVE,
+	.attrs = DEVFREQ_GOV_ATTR_TARGET_FREQ,
 	.get_target_freq = devfreq_powersave_func,
 	.event_handler = devfreq_powersave_handler,
 };