--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AMD 3D V-Cache Performance Optimizer Driver
+ *
+ * Copyright (c) 2024, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Authors: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
+ * Perry Yuan <perry.yuan@amd.com>
+ * Mario Limonciello <mario.limonciello@amd.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/array_size.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/sysfs.h>
+#include <linux/uuid.h>
+
+static char *x3d_mode = "frequency";
+module_param(x3d_mode, charp, 0);
+MODULE_PARM_DESC(x3d_mode, "Initial 3D-VCache mode; 'frequency' (default) or 'cache'");
+
+#define DSM_REVISION_ID 0
+#define DSM_SET_X3D_MODE 1
+
+static guid_t x3d_guid = GUID_INIT(0xdff8e55f, 0xbcfd, 0x46fb, 0xba, 0x0a,
+ 0xef, 0xd0, 0x45, 0x0f, 0x34, 0xee);
+
+enum amd_x3d_mode_type {
+ MODE_INDEX_FREQ,
+ MODE_INDEX_CACHE,
+};
+
+static const char * const amd_x3d_mode_strings[] = {
+ [MODE_INDEX_FREQ] = "frequency",
+ [MODE_INDEX_CACHE] = "cache",
+};
+
+struct amd_x3d_dev {
+ struct device *dev;
+ acpi_handle ahandle;
+ /* To protect x3d mode setting */
+ struct mutex lock;
+ enum amd_x3d_mode_type curr_mode;
+};
+
+static int amd_x3d_get_mode(struct amd_x3d_dev *data)
+{
+ guard(mutex)(&data->lock);
+
+ return data->curr_mode;
+}
+
+static int amd_x3d_mode_switch(struct amd_x3d_dev *data, int new_state)
+{
+ union acpi_object *out, argv;
+
+ guard(mutex)(&data->lock);
+ argv.type = ACPI_TYPE_INTEGER;
+ argv.integer.value = new_state;
+
+ out = acpi_evaluate_dsm(data->ahandle, &x3d_guid, DSM_REVISION_ID,
+ DSM_SET_X3D_MODE, &argv);
+ if (!out) {
+ dev_err(data->dev, "failed to evaluate _DSM\n");
+ return -EINVAL;
+ }
+
+ data->curr_mode = new_state;
+
+ kfree(out);
+
+ return 0;
+}
+
+static ssize_t amd_x3d_mode_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct amd_x3d_dev *data = dev_get_drvdata(dev);
+ int ret;
+
+ ret = sysfs_match_string(amd_x3d_mode_strings, buf);
+ if (ret < 0)
+ return ret;
+
+ ret = amd_x3d_mode_switch(data, ret);
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+static ssize_t amd_x3d_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct amd_x3d_dev *data = dev_get_drvdata(dev);
+ int mode = amd_x3d_get_mode(data);
+
+ return sysfs_emit(buf, "%s\n", amd_x3d_mode_strings[mode]);
+}
+static DEVICE_ATTR_RW(amd_x3d_mode);
+
+static struct attribute *amd_x3d_attrs[] = {
+ &dev_attr_amd_x3d_mode.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(amd_x3d);
+
+static int amd_x3d_resume_handler(struct device *dev)
+{
+ struct amd_x3d_dev *data = dev_get_drvdata(dev);
+ int ret = amd_x3d_get_mode(data);
+
+ return amd_x3d_mode_switch(data, ret);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(amd_x3d_pm, NULL, amd_x3d_resume_handler);
+
+static const struct acpi_device_id amd_x3d_acpi_ids[] = {
+ {"AMDI0101"},
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, amd_x3d_acpi_ids);
+
+static int amd_x3d_probe(struct platform_device *pdev)
+{
+ struct amd_x3d_dev *data;
+ acpi_handle handle;
+ int ret;
+
+ handle = ACPI_HANDLE(&pdev->dev);
+ if (!handle)
+ return -ENODEV;
+
+ if (!acpi_check_dsm(handle, &x3d_guid, DSM_REVISION_ID, BIT(DSM_SET_X3D_MODE)))
+ return -ENODEV;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = &pdev->dev;
+
+ ret = devm_mutex_init(data->dev, &data->lock);
+ if (ret)
+ return ret;
+
+ data->ahandle = handle;
+ platform_set_drvdata(pdev, data);
+
+ ret = match_string(amd_x3d_mode_strings, ARRAY_SIZE(amd_x3d_mode_strings), x3d_mode);
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, -EINVAL, "invalid mode %s\n", x3d_mode);
+
+ return amd_x3d_mode_switch(data, ret);
+}
+
+static struct platform_driver amd_3d_vcache_driver = {
+ .driver = {
+ .name = "amd_x3d_vcache",
+ .dev_groups = amd_x3d_groups,
+ .acpi_match_table = amd_x3d_acpi_ids,
+ .pm = pm_sleep_ptr(&amd_x3d_pm),
+ },
+ .probe = amd_x3d_probe,
+};
+module_platform_driver(amd_3d_vcache_driver);
+
+MODULE_DESCRIPTION("AMD 3D V-Cache Performance Optimizer Driver");
+MODULE_LICENSE("GPL");
projects / users / jedix / linux-maple.git / commitdiff