diff options
Diffstat (limited to 'drivers/platform/x86/amd/x3d_vcache.c')
| -rw-r--r-- | drivers/platform/x86/amd/x3d_vcache.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/platform/x86/amd/x3d_vcache.c b/drivers/platform/x86/amd/x3d_vcache.c new file mode 100644 index 000000000000..0f6d3c54d879 --- /dev/null +++ b/drivers/platform/x86/amd/x3d_vcache.c @@ -0,0 +1,176 @@ +// 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"); |