msm: kgsl: Add a sysfs node to control performance counter reads

Currently performance counters are global and can be read by anyone. Change
the behaviour to disable reading global counters as default and add a sysfs
node to enable/disable reads.

Change-Id: Ic3785acd9bd7425c2a844ed103d7b870d9f80adf
Signed-off-by: Mohammed Mirza Mandayappurath Manzoor <quic_mmandaya@quicinc.com>
Signed-off-by: Pankaj Gupta <quic_gpankaj@quicinc.com>
Signed-off-by: Harshitha Sai Neelati <quic_hsaineel@quicinc.com>

drivers/gpu/msm/adreno.c

@@ -1,4 +1,5 @@
 /* Copyright (c) 2002,2007-2018,2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1426,6 +1427,8 @@ static int adreno_probe(struct platform_device *pdev)
 	adreno_debugfs_init(adreno_dev);
 	adreno_profile_init(adreno_dev);
 
+	adreno_dev->perfcounter = false;
+
 	adreno_sysfs_init(adreno_dev);
 
 	kgsl_pwrscale_init(&pdev->dev, CONFIG_QCOM_ADRENO_DEFAULT_GOVERNOR);

drivers/gpu/msm/adreno.h

@@ -1,4 +1,5 @@
 /* Copyright (c) 2008-2018,2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -578,6 +579,11 @@ struct adreno_device {
 	bool gpuhtw_llc_slice_enable;
 	unsigned int zap_loaded;
 	unsigned int soc_hw_rev;
+	/*
+	 * @perfcounter: Flag to clear perfcounters across contexts and
+	 * controls perfcounter ioctl read
+	 */
+	bool perfcounter;
 };
 
 /**

drivers/gpu/msm/adreno_compat.c

@@ -1,4 +1,5 @@
 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -260,6 +261,14 @@ static long adreno_ioctl_perfcounter_read_compat(
 	struct kgsl_perfcounter_read_compat *read32 = data;
 	struct kgsl_perfcounter_read read;
 
+	/*
+	 * When performance counter zapping is enabled, the counters are cleared
+	 * across context switches. Reading the counters when they are zapped is
+	 * not permitted.
+	 */
+	if (!adreno_dev->perfcounter)
+		return -EPERM;
+
 	read.reads = (struct kgsl_perfcounter_read_group __user *)
 		(uintptr_t)read32->reads;
 	read.count = read32->count;

drivers/gpu/msm/adreno_ioctl.c

@@ -1,4 +1,5 @@
 /* Copyright (c) 2002,2007-2018,2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -141,6 +142,14 @@ static long adreno_ioctl_perfcounter_read(struct kgsl_device_private *dev_priv,
 	struct adreno_device *adreno_dev = ADRENO_DEVICE(dev_priv->device);
 	struct kgsl_perfcounter_read *read = data;
 
+	/*
+	 * When performance counter zapping is enabled, the counters are cleared
+	 * across context switches. Reading the counters when they are zapped is
+	 * not permitted.
+	 */
+	if (!adreno_dev->perfcounter)
+		return -EPERM;
+
 	return (long) adreno_perfcounter_read_group(adreno_dev, read->reads,
 		read->count);
 }

drivers/gpu/msm/adreno_sysfs.c

@@ -1,4 +1,5 @@
 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -353,6 +354,31 @@ static unsigned int _preempt_count_show(struct adreno_device *adreno_dev)
 	return preempt->count;
 }
 
+static unsigned int _perfcounter_show(struct adreno_device *adreno_dev)
+{
+	return adreno_dev->perfcounter;
+}
+
+static int _perfcounter_store(struct adreno_device *adreno_dev,
+		unsigned int val)
+{
+	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
+
+	if (adreno_dev->perfcounter == val)
+		return 0;
+
+	mutex_lock(&device->mutex);
+
+	/* Power down the GPU before changing the state */
+	kgsl_pwrctrl_change_state(device, KGSL_STATE_SUSPEND);
+	adreno_dev->perfcounter = val;
+	kgsl_pwrctrl_change_state(device, KGSL_STATE_SLUMBER);
+
+	mutex_unlock(&device->mutex);
+
+	return 0;
+}
+
 static ssize_t _sysfs_store_u32(struct device *dev,
 		struct device_attribute *attr,
 		const char *buf, size_t count)
@@ -457,6 +483,7 @@ static ADRENO_SYSFS_BOOL(hwcg);
 static ADRENO_SYSFS_BOOL(throttling);
 static ADRENO_SYSFS_BOOL(ifpc);
 static ADRENO_SYSFS_RO_U32(ifpc_count);
+static ADRENO_SYSFS_BOOL(perfcounter);
 
 
 
@@ -480,6 +507,7 @@ static const struct device_attribute *_attr_list[] = {
 	&adreno_attr_ifpc.attr,
 	&adreno_attr_ifpc_count.attr,
 	&adreno_attr_preempt_count.attr,
+	&adreno_attr_perfcounter.attr,
 	NULL,
 };
 
@@ -637,8 +665,11 @@ int adreno_sysfs_init(struct adreno_device *adreno_dev)
 	ret = kgsl_create_device_sysfs_files(device->dev, _attr_list);
 
 	/* Add the PPD directory and files */
-	if (ret == 0)
+	if (ret == 0) {
+		/* Notify userspace */
+		kobject_uevent(&device->dev->kobj, KOBJ_ADD);
 		ppd_sysfs_init(adreno_dev);
+	}
 
 	return 0;
 }