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[v3,1/2] platform/x86/amd: amd_3d_vcache: Add AMD 3D V-Cache optimizer driver

Message ID 20241021165820.339567-2-Basavaraj.Natikar@amd.com (mailing list archive)
State Changes Requested, archived
Headers show
Series Add support of AMD 3D V-Cache optimizer driver | expand

Commit Message

Basavaraj Natikar Oct. 21, 2024, 4:58 p.m. UTC
AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
switching between Frequency and Cache modes. To optimize performance,
implement the AMD 3D V-Cache Optimizer, which allows selecting either:

Frequency mode: cores within the faster CCD are prioritized before
those in the slower CCD.

Cache mode: cores within the larger L3 CCD are prioritized before
those in the smaller L3 CCD.

Co-developed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
 MAINTAINERS                           |   7 ++
 drivers/platform/x86/amd/Kconfig      |  12 ++
 drivers/platform/x86/amd/Makefile     |   2 +
 drivers/platform/x86/amd/x3d_vcache.c | 174 ++++++++++++++++++++++++++
 4 files changed, 195 insertions(+)
 create mode 100644 drivers/platform/x86/amd/x3d_vcache.c

Comments

Armin Wolf Oct. 21, 2024, 8:35 p.m. UTC | #1
Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:

> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
> switching between Frequency and Cache modes. To optimize performance,
> implement the AMD 3D V-Cache Optimizer, which allows selecting either:
>
> Frequency mode: cores within the faster CCD are prioritized before
> those in the slower CCD.
>
> Cache mode: cores within the larger L3 CCD are prioritized before
> those in the smaller L3 CCD.
>
> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
> ---
>   MAINTAINERS                           |   7 ++
>   drivers/platform/x86/amd/Kconfig      |  12 ++
>   drivers/platform/x86/amd/Makefile     |   2 +
>   drivers/platform/x86/amd/x3d_vcache.c | 174 ++++++++++++++++++++++++++
>   4 files changed, 195 insertions(+)
>   create mode 100644 drivers/platform/x86/amd/x3d_vcache.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e9659a5a7fb3..11b829956499 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -965,6 +965,13 @@ Q:	https://patchwork.kernel.org/project/linux-rdma/list/
>   F:	drivers/infiniband/hw/efa/
>   F:	include/uapi/rdma/efa-abi.h
>
> +AMD 3D V-CACHE PERFORMANCE OPTIMIZER DRIVER
> +M:	Basavaraj Natikar <Basavaraj.Natikar@amd.com>
> +R:	Mario Limonciello <mario.limonciello@amd.com>
> +L:	platform-driver-x86@vger.kernel.org
> +S:	Supported
> +F:	drivers/platform/x86/amd/x3d_vcache.c
> +
>   AMD ADDRESS TRANSLATION LIBRARY (ATL)
>   M:	Yazen Ghannam <Yazen.Ghannam@amd.com>
>   L:	linux-edac@vger.kernel.org
> diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig
> index f88682d36447..d73f691020d0 100644
> --- a/drivers/platform/x86/amd/Kconfig
> +++ b/drivers/platform/x86/amd/Kconfig
> @@ -6,6 +6,18 @@
>   source "drivers/platform/x86/amd/pmf/Kconfig"
>   source "drivers/platform/x86/amd/pmc/Kconfig"
>
> +config AMD_3D_VCACHE
> +	tristate "AMD 3D V-Cache Performance Optimizer Driver"
> +	depends on X86_64 && ACPI
> +	help
> +	  The driver provides a sysfs interface, enabling the setting of a bias
> +	  that alters CPU core reordering. This bias prefers cores with higher
> +	  frequencies or larger L3 caches on processors supporting AMD 3D V-Cache
> +	  technology.
> +
> +	  If you choose to compile this driver as a module the module will be
> +	  called amd_3d_vcache.
> +
>   config AMD_HSMP
>   	tristate "AMD HSMP Driver"
>   	depends on AMD_NB && X86_64 && ACPI
> diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile
> index dcec0a46f8af..16e4cce02242 100644
> --- a/drivers/platform/x86/amd/Makefile
> +++ b/drivers/platform/x86/amd/Makefile
> @@ -4,6 +4,8 @@
>   # AMD x86 Platform-Specific Drivers
>   #
>
> +obj-$(CONFIG_AMD_3D_VCACHE)     += amd_3d_vcache.o
> +amd_3d_vcache-objs              := x3d_vcache.o
>   obj-$(CONFIG_AMD_PMC)		+= pmc/
>   amd_hsmp-y			:= hsmp.o
>   obj-$(CONFIG_AMD_HSMP)		+= amd_hsmp.o
> diff --git a/drivers/platform/x86/amd/x3d_vcache.c b/drivers/platform/x86/amd/x3d_vcache.c
> new file mode 100644
> index 000000000000..833e7704e6f9
> --- /dev/null
> +++ b/drivers/platform/x86/amd/x3d_vcache.c
> @@ -0,0 +1,174 @@
> +// 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/device.h>
> +#include <linux/errno.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.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);
> +
> +	ret = amd_x3d_mode_switch(data, ret);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;

Please directly return the result of amd_x3d_mode_switch() here.

Also i think that maybe there exists a way to avoid locking data->lock twice
during resume, but i will leave that to you.
Other than that:

Reviewed-by: Armin Wolf <W_Armin@gmx.de>

> +}
> +
> +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;
> +	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);
> +
> +	devm_mutex_init(data->dev, &data->lock);
> +
> +	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");
Basavaraj Natikar Oct. 22, 2024, 5:54 a.m. UTC | #2
On 10/22/2024 2:05 AM, Armin Wolf wrote:
> Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
>
>> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
>> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
>> switching between Frequency and Cache modes. To optimize performance,
>> implement the AMD 3D V-Cache Optimizer, which allows selecting either:
>>
>> Frequency mode: cores within the faster CCD are prioritized before
>> those in the slower CCD.
>>
>> Cache mode: cores within the larger L3 CCD are prioritized before
>> those in the smaller L3 CCD.
>>
>> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
>> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
>> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>> ---
>>   MAINTAINERS                           |   7 ++
>>   drivers/platform/x86/amd/Kconfig      |  12 ++
>>   drivers/platform/x86/amd/Makefile     |   2 +
>>   drivers/platform/x86/amd/x3d_vcache.c | 174 ++++++++++++++++++++++++++
>>   4 files changed, 195 insertions(+)
>>   create mode 100644 drivers/platform/x86/amd/x3d_vcache.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e9659a5a7fb3..11b829956499 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -965,6 +965,13 @@ Q: 
>> https://patchwork.kernel.org/project/linux-rdma/list/
>>   F:    drivers/infiniband/hw/efa/
>>   F:    include/uapi/rdma/efa-abi.h
>>
>> +AMD 3D V-CACHE PERFORMANCE OPTIMIZER DRIVER
>> +M:    Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>> +R:    Mario Limonciello <mario.limonciello@amd.com>
>> +L:    platform-driver-x86@vger.kernel.org
>> +S:    Supported
>> +F:    drivers/platform/x86/amd/x3d_vcache.c
>> +
>>   AMD ADDRESS TRANSLATION LIBRARY (ATL)
>>   M:    Yazen Ghannam <Yazen.Ghannam@amd.com>
>>   L:    linux-edac@vger.kernel.org
>> diff --git a/drivers/platform/x86/amd/Kconfig 
>> b/drivers/platform/x86/amd/Kconfig
>> index f88682d36447..d73f691020d0 100644
>> --- a/drivers/platform/x86/amd/Kconfig
>> +++ b/drivers/platform/x86/amd/Kconfig
>> @@ -6,6 +6,18 @@
>>   source "drivers/platform/x86/amd/pmf/Kconfig"
>>   source "drivers/platform/x86/amd/pmc/Kconfig"
>>
>> +config AMD_3D_VCACHE
>> +    tristate "AMD 3D V-Cache Performance Optimizer Driver"
>> +    depends on X86_64 && ACPI
>> +    help
>> +      The driver provides a sysfs interface, enabling the setting of 
>> a bias
>> +      that alters CPU core reordering. This bias prefers cores with 
>> higher
>> +      frequencies or larger L3 caches on processors supporting AMD 
>> 3D V-Cache
>> +      technology.
>> +
>> +      If you choose to compile this driver as a module the module 
>> will be
>> +      called amd_3d_vcache.
>> +
>>   config AMD_HSMP
>>       tristate "AMD HSMP Driver"
>>       depends on AMD_NB && X86_64 && ACPI
>> diff --git a/drivers/platform/x86/amd/Makefile 
>> b/drivers/platform/x86/amd/Makefile
>> index dcec0a46f8af..16e4cce02242 100644
>> --- a/drivers/platform/x86/amd/Makefile
>> +++ b/drivers/platform/x86/amd/Makefile
>> @@ -4,6 +4,8 @@
>>   # AMD x86 Platform-Specific Drivers
>>   #
>>
>> +obj-$(CONFIG_AMD_3D_VCACHE)     += amd_3d_vcache.o
>> +amd_3d_vcache-objs              := x3d_vcache.o
>>   obj-$(CONFIG_AMD_PMC)        += pmc/
>>   amd_hsmp-y            := hsmp.o
>>   obj-$(CONFIG_AMD_HSMP)        += amd_hsmp.o
>> diff --git a/drivers/platform/x86/amd/x3d_vcache.c 
>> b/drivers/platform/x86/amd/x3d_vcache.c
>> new file mode 100644
>> index 000000000000..833e7704e6f9
>> --- /dev/null
>> +++ b/drivers/platform/x86/amd/x3d_vcache.c
>> @@ -0,0 +1,174 @@
>> +// 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/device.h>
>> +#include <linux/errno.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/platform_device.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);
>> +
>> +    ret = amd_x3d_mode_switch(data, ret);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    return 0;
>
> Please directly return the result of amd_x3d_mode_switch() here.
>
> Also i think that maybe there exists a way to avoid locking data->lock 
> twice
> during resume, but i will leave that to you.

I will leave as it is.

> Other than that:
>
> Reviewed-by: Armin Wolf <W_Armin@gmx.de>

Thanks for the feedback. I will re-spin a new version after looking for 
more feedback from others. Thanks, -- Basavaraj

>
>> +}
>> +
>> +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;
>> +    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);
>> +
>> +    devm_mutex_init(data->dev, &data->lock);
>> +
>> +    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");
Mario Limonciello Oct. 22, 2024, 1:05 p.m. UTC | #3
On 10/22/2024 00:54, Basavaraj Natikar wrote:
> 
> On 10/22/2024 2:05 AM, Armin Wolf wrote:
>> Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
>>
>>> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
>>> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
>>> switching between Frequency and Cache modes. To optimize performance,
>>> implement the AMD 3D V-Cache Optimizer, which allows selecting either:
>>>
>>> Frequency mode: cores within the faster CCD are prioritized before
>>> those in the slower CCD.
>>>
>>> Cache mode: cores within the larger L3 CCD are prioritized before
>>> those in the smaller L3 CCD.
>>>
>>> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
>>> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
>>> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>>> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>>> ---
>>>   MAINTAINERS                           |   7 ++
>>>   drivers/platform/x86/amd/Kconfig      |  12 ++
>>>   drivers/platform/x86/amd/Makefile     |   2 +
>>>   drivers/platform/x86/amd/x3d_vcache.c | 174 ++++++++++++++++++++++++++
>>>   4 files changed, 195 insertions(+)
>>>   create mode 100644 drivers/platform/x86/amd/x3d_vcache.c
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index e9659a5a7fb3..11b829956499 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -965,6 +965,13 @@ Q: https://patchwork.kernel.org/project/linux- 
>>> rdma/list/
>>>   F:    drivers/infiniband/hw/efa/
>>>   F:    include/uapi/rdma/efa-abi.h
>>>
>>> +AMD 3D V-CACHE PERFORMANCE OPTIMIZER DRIVER
>>> +M:    Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>>> +R:    Mario Limonciello <mario.limonciello@amd.com>
>>> +L:    platform-driver-x86@vger.kernel.org
>>> +S:    Supported
>>> +F:    drivers/platform/x86/amd/x3d_vcache.c
>>> +
>>>   AMD ADDRESS TRANSLATION LIBRARY (ATL)
>>>   M:    Yazen Ghannam <Yazen.Ghannam@amd.com>
>>>   L:    linux-edac@vger.kernel.org
>>> diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/ 
>>> amd/Kconfig
>>> index f88682d36447..d73f691020d0 100644
>>> --- a/drivers/platform/x86/amd/Kconfig
>>> +++ b/drivers/platform/x86/amd/Kconfig
>>> @@ -6,6 +6,18 @@
>>>   source "drivers/platform/x86/amd/pmf/Kconfig"
>>>   source "drivers/platform/x86/amd/pmc/Kconfig"
>>>
>>> +config AMD_3D_VCACHE
>>> +    tristate "AMD 3D V-Cache Performance Optimizer Driver"
>>> +    depends on X86_64 && ACPI
>>> +    help
>>> +      The driver provides a sysfs interface, enabling the setting of 
>>> a bias
>>> +      that alters CPU core reordering. This bias prefers cores with 
>>> higher
>>> +      frequencies or larger L3 caches on processors supporting AMD 
>>> 3D V-Cache
>>> +      technology.
>>> +
>>> +      If you choose to compile this driver as a module the module 
>>> will be
>>> +      called amd_3d_vcache.
>>> +
>>>   config AMD_HSMP
>>>       tristate "AMD HSMP Driver"
>>>       depends on AMD_NB && X86_64 && ACPI
>>> diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/ 
>>> x86/amd/Makefile
>>> index dcec0a46f8af..16e4cce02242 100644
>>> --- a/drivers/platform/x86/amd/Makefile
>>> +++ b/drivers/platform/x86/amd/Makefile
>>> @@ -4,6 +4,8 @@
>>>   # AMD x86 Platform-Specific Drivers
>>>   #
>>>
>>> +obj-$(CONFIG_AMD_3D_VCACHE)     += amd_3d_vcache.o
>>> +amd_3d_vcache-objs              := x3d_vcache.o
>>>   obj-$(CONFIG_AMD_PMC)        += pmc/
>>>   amd_hsmp-y            := hsmp.o
>>>   obj-$(CONFIG_AMD_HSMP)        += amd_hsmp.o
>>> diff --git a/drivers/platform/x86/amd/x3d_vcache.c b/drivers/ 
>>> platform/x86/amd/x3d_vcache.c
>>> new file mode 100644
>>> index 000000000000..833e7704e6f9
>>> --- /dev/null
>>> +++ b/drivers/platform/x86/amd/x3d_vcache.c
>>> @@ -0,0 +1,174 @@
>>> +// 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/device.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/platform_device.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);
>>> +
>>> +    ret = amd_x3d_mode_switch(data, ret);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    return 0;
>>
>> Please directly return the result of amd_x3d_mode_switch() here.
>>
>> Also i think that maybe there exists a way to avoid locking data->lock 
>> twice
>> during resume, but i will leave that to you.
> 
> I will leave as it is.
> 
>> Other than that:
>>
>> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
> 
> Thanks for the feedback. I will re-spin a new version after looking for 
> more feedback from others. Thanks, -- Basavaraj
> 

FYI - if no other feedback comes in there is no need to re-spin just to 
add R-b tags.  Maintainers will automatically pick them up when they use 
'b4 $LORE_URL'.
Ilpo Järvinen Oct. 22, 2024, 1:22 p.m. UTC | #4
On Tue, 22 Oct 2024, Mario Limonciello wrote:

> On 10/22/2024 00:54, Basavaraj Natikar wrote:
> > 
> > On 10/22/2024 2:05 AM, Armin Wolf wrote:
> > > Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
> > > 
> > > > AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
> > > > Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
> > > > switching between Frequency and Cache modes. To optimize performance,
> > > > implement the AMD 3D V-Cache Optimizer, which allows selecting either:
> > > > 
> > > > Frequency mode: cores within the faster CCD are prioritized before
> > > > those in the slower CCD.
> > > > 
> > > > Cache mode: cores within the larger L3 CCD are prioritized before
> > > > those in the smaller L3 CCD.
> > > > 
> > > > Co-developed-by: Perry Yuan <perry.yuan@amd.com>
> > > > Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> > > > Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
> > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> > > > Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > > Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>

> > > > +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);
> > > > +
> > > > +    ret = amd_x3d_mode_switch(data, ret);
> > > > +    if (ret < 0)
> > > > +        return ret;
> > > > +
> > > > +    return 0;
> > > 
> > > Please directly return the result of amd_x3d_mode_switch() here.
> > > 
> > > Also i think that maybe there exists a way to avoid locking data->lock
> > > twice
> > > during resume, but i will leave that to you.
> > 
> > I will leave as it is.
> > 
> > > Other than that:
> > > 
> > > Reviewed-by: Armin Wolf <W_Armin@gmx.de>
> > 
> > Thanks for the feedback. I will re-spin a new version after looking for more
> > feedback from others. Thanks, -- Basavaraj
> > 
> 
> FYI - if no other feedback comes in there is no need to re-spin just to add
> R-b tags.  Maintainers will automatically pick them up when they use 'b4
> $LORE_URL'.

?? There's the return change requested above.
Basavaraj Natikar Oct. 22, 2024, 1:34 p.m. UTC | #5
On 10/22/2024 6:52 PM, Ilpo Järvinen wrote:
> On Tue, 22 Oct 2024, Mario Limonciello wrote:
>
>> On 10/22/2024 00:54, Basavaraj Natikar wrote:
>>> On 10/22/2024 2:05 AM, Armin Wolf wrote:
>>>> Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
>>>>
>>>>> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
>>>>> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
>>>>> switching between Frequency and Cache modes. To optimize performance,
>>>>> implement the AMD 3D V-Cache Optimizer, which allows selecting either:
>>>>>
>>>>> Frequency mode: cores within the faster CCD are prioritized before
>>>>> those in the slower CCD.
>>>>>
>>>>> Cache mode: cores within the larger L3 CCD are prioritized before
>>>>> those in the smaller L3 CCD.
>>>>>
>>>>> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
>>>>> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
>>>>> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>>>>> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>>>>> +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);
>>>>> +
>>>>> +    ret = amd_x3d_mode_switch(data, ret);
>>>>> +    if (ret < 0)
>>>>> +        return ret;
>>>>> +
>>>>> +    return 0;
>>>> Please directly return the result of amd_x3d_mode_switch() here.
>>>>
>>>> Also i think that maybe there exists a way to avoid locking data->lock
>>>> twice
>>>> during resume, but i will leave that to you.
>>> I will leave as it is.
>>>
>>>> Other than that:
>>>>
>>>> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
>>> Thanks for the feedback. I will re-spin a new version after looking for more
>>> feedback from others. Thanks, -- Basavaraj
>>>
>> FYI - if no other feedback comes in there is no need to re-spin just to add
>> R-b tags.  Maintainers will automatically pick them up when they use 'b4
>> $LORE_URL'.
> ?? There's the return change requested above.

Yes, I will include above return change and re-spin a new version after
looking for more feedback from others.

Thanks,
--
Basavaraj

>
Mario Limonciello Oct. 22, 2024, 1:46 p.m. UTC | #6
On 10/22/2024 08:22, Ilpo Järvinen wrote:
> On Tue, 22 Oct 2024, Mario Limonciello wrote:
> 
>> On 10/22/2024 00:54, Basavaraj Natikar wrote:
>>>
>>> On 10/22/2024 2:05 AM, Armin Wolf wrote:
>>>> Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
>>>>
>>>>> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
>>>>> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
>>>>> switching between Frequency and Cache modes. To optimize performance,
>>>>> implement the AMD 3D V-Cache Optimizer, which allows selecting either:
>>>>>
>>>>> Frequency mode: cores within the faster CCD are prioritized before
>>>>> those in the slower CCD.
>>>>>
>>>>> Cache mode: cores within the larger L3 CCD are prioritized before
>>>>> those in the smaller L3 CCD.
>>>>>
>>>>> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
>>>>> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
>>>>> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>>>>> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
> 
>>>>> +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);
>>>>> +
>>>>> +    ret = amd_x3d_mode_switch(data, ret);
>>>>> +    if (ret < 0)
>>>>> +        return ret;
>>>>> +
>>>>> +    return 0;
>>>>
>>>> Please directly return the result of amd_x3d_mode_switch() here.
>>>>
>>>> Also i think that maybe there exists a way to avoid locking data->lock
>>>> twice
>>>> during resume, but i will leave that to you.
>>>
>>> I will leave as it is.
>>>
>>>> Other than that:
>>>>
>>>> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
>>>
>>> Thanks for the feedback. I will re-spin a new version after looking for more
>>> feedback from others. Thanks, -- Basavaraj
>>>
>>
>> FYI - if no other feedback comes in there is no need to re-spin just to add
>> R-b tags.  Maintainers will automatically pick them up when they use 'b4
>> $LORE_URL'.
> 
> ?? There's the return change requested above.
> 

Basavaraj said he will leave it as is in response to Armin's comment.
Ilpo Järvinen Oct. 22, 2024, 1:59 p.m. UTC | #7
On Tue, 22 Oct 2024, Mario Limonciello wrote:

> On 10/22/2024 08:22, Ilpo Järvinen wrote:
> > On Tue, 22 Oct 2024, Mario Limonciello wrote:
> > 
> > > On 10/22/2024 00:54, Basavaraj Natikar wrote:
> > > > 
> > > > On 10/22/2024 2:05 AM, Armin Wolf wrote:
> > > > > Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
> > > > > 
> > > > > > AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
> > > > > > Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
> > > > > > switching between Frequency and Cache modes. To optimize
> > > > > > performance,
> > > > > > implement the AMD 3D V-Cache Optimizer, which allows selecting
> > > > > > either:
> > > > > > 
> > > > > > Frequency mode: cores within the faster CCD are prioritized before
> > > > > > those in the slower CCD.
> > > > > > 
> > > > > > Cache mode: cores within the larger L3 CCD are prioritized before
> > > > > > those in the smaller L3 CCD.
> > > > > > 
> > > > > > Co-developed-by: Perry Yuan <perry.yuan@amd.com>
> > > > > > Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> > > > > > Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
> > > > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> > > > > > Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > > > > Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
> > 
> > > > > > +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);
> > > > > > +
> > > > > > +    ret = amd_x3d_mode_switch(data, ret);
> > > > > > +    if (ret < 0)
> > > > > > +        return ret;
> > > > > > +
> > > > > > +    return 0;
> > > > > 
> > > > > Please directly return the result of amd_x3d_mode_switch() here.
> > > > > 
> > > > > Also i think that maybe there exists a way to avoid locking data->lock
> > > > > twice
> > > > > during resume, but i will leave that to you.
> > > > 
> > > > I will leave as it is.
> > > > 
> > > > > Other than that:
> > > > > 
> > > > > Reviewed-by: Armin Wolf <W_Armin@gmx.de>
> > > > 
> > > > Thanks for the feedback. I will re-spin a new version after looking for
> > > > more
> > > > feedback from others. Thanks, -- Basavaraj
> > > > 
> > > 
> > > FYI - if no other feedback comes in there is no need to re-spin just to
> > > add
> > > R-b tags.  Maintainers will automatically pick them up when they use 'b4
> > > $LORE_URL'.
> > 
> > ?? There's the return change requested above.
> > 
> 
> Basavaraj said he will leave it as is in response to Armin's comment.

To me that seemed related to the locking paragraph, not the return related 
one.
Mario Limonciello Oct. 22, 2024, 2 p.m. UTC | #8
On 10/22/2024 08:59, Ilpo Järvinen wrote:
> On Tue, 22 Oct 2024, Mario Limonciello wrote:
> 
>> On 10/22/2024 08:22, Ilpo Järvinen wrote:
>>> On Tue, 22 Oct 2024, Mario Limonciello wrote:
>>>
>>>> On 10/22/2024 00:54, Basavaraj Natikar wrote:
>>>>>
>>>>> On 10/22/2024 2:05 AM, Armin Wolf wrote:
>>>>>> Am 21.10.24 um 18:58 schrieb Basavaraj Natikar:
>>>>>>
>>>>>>> AMD X3D processors, also known as AMD 3D V-Cache, feature dual Core
>>>>>>> Complex Dies (CCDs) and enlarged L3 cache, enabling dynamic mode
>>>>>>> switching between Frequency and Cache modes. To optimize
>>>>>>> performance,
>>>>>>> implement the AMD 3D V-Cache Optimizer, which allows selecting
>>>>>>> either:
>>>>>>>
>>>>>>> Frequency mode: cores within the faster CCD are prioritized before
>>>>>>> those in the slower CCD.
>>>>>>>
>>>>>>> Cache mode: cores within the larger L3 CCD are prioritized before
>>>>>>> those in the smaller L3 CCD.
>>>>>>>
>>>>>>> Co-developed-by: Perry Yuan <perry.yuan@amd.com>
>>>>>>> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
>>>>>>> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>>>> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>>>>>>> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
>>>
>>>>>>> +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);
>>>>>>> +
>>>>>>> +    ret = amd_x3d_mode_switch(data, ret);
>>>>>>> +    if (ret < 0)
>>>>>>> +        return ret;
>>>>>>> +
>>>>>>> +    return 0;
>>>>>>
>>>>>> Please directly return the result of amd_x3d_mode_switch() here.
>>>>>>
>>>>>> Also i think that maybe there exists a way to avoid locking data->lock
>>>>>> twice
>>>>>> during resume, but i will leave that to you.
>>>>>
>>>>> I will leave as it is.
>>>>>
>>>>>> Other than that:
>>>>>>
>>>>>> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
>>>>>
>>>>> Thanks for the feedback. I will re-spin a new version after looking for
>>>>> more
>>>>> feedback from others. Thanks, -- Basavaraj
>>>>>
>>>>
>>>> FYI - if no other feedback comes in there is no need to re-spin just to
>>>> add
>>>> R-b tags.  Maintainers will automatically pick them up when they use 'b4
>>>> $LORE_URL'.
>>>
>>> ?? There's the return change requested above.
>>>
>>
>> Basavaraj said he will leave it as is in response to Armin's comment.
> 
> To me that seemed related to the locking paragraph, not the return related
> one.
> 

Ah I see; thanks for correcting my misreading.
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e9659a5a7fb3..11b829956499 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -965,6 +965,13 @@  Q:	https://patchwork.kernel.org/project/linux-rdma/list/
 F:	drivers/infiniband/hw/efa/
 F:	include/uapi/rdma/efa-abi.h
 
+AMD 3D V-CACHE PERFORMANCE OPTIMIZER DRIVER
+M:	Basavaraj Natikar <Basavaraj.Natikar@amd.com>
+R:	Mario Limonciello <mario.limonciello@amd.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Supported
+F:	drivers/platform/x86/amd/x3d_vcache.c
+
 AMD ADDRESS TRANSLATION LIBRARY (ATL)
 M:	Yazen Ghannam <Yazen.Ghannam@amd.com>
 L:	linux-edac@vger.kernel.org
diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig
index f88682d36447..d73f691020d0 100644
--- a/drivers/platform/x86/amd/Kconfig
+++ b/drivers/platform/x86/amd/Kconfig
@@ -6,6 +6,18 @@ 
 source "drivers/platform/x86/amd/pmf/Kconfig"
 source "drivers/platform/x86/amd/pmc/Kconfig"
 
+config AMD_3D_VCACHE
+	tristate "AMD 3D V-Cache Performance Optimizer Driver"
+	depends on X86_64 && ACPI
+	help
+	  The driver provides a sysfs interface, enabling the setting of a bias
+	  that alters CPU core reordering. This bias prefers cores with higher
+	  frequencies or larger L3 caches on processors supporting AMD 3D V-Cache
+	  technology.
+
+	  If you choose to compile this driver as a module the module will be
+	  called amd_3d_vcache.
+
 config AMD_HSMP
 	tristate "AMD HSMP Driver"
 	depends on AMD_NB && X86_64 && ACPI
diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile
index dcec0a46f8af..16e4cce02242 100644
--- a/drivers/platform/x86/amd/Makefile
+++ b/drivers/platform/x86/amd/Makefile
@@ -4,6 +4,8 @@ 
 # AMD x86 Platform-Specific Drivers
 #
 
+obj-$(CONFIG_AMD_3D_VCACHE)     += amd_3d_vcache.o
+amd_3d_vcache-objs              := x3d_vcache.o
 obj-$(CONFIG_AMD_PMC)		+= pmc/
 amd_hsmp-y			:= hsmp.o
 obj-$(CONFIG_AMD_HSMP)		+= amd_hsmp.o
diff --git a/drivers/platform/x86/amd/x3d_vcache.c b/drivers/platform/x86/amd/x3d_vcache.c
new file mode 100644
index 000000000000..833e7704e6f9
--- /dev/null
+++ b/drivers/platform/x86/amd/x3d_vcache.c
@@ -0,0 +1,174 @@ 
+// 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/device.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.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);
+
+	ret = amd_x3d_mode_switch(data, ret);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+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;
+	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);
+
+	devm_mutex_init(data->dev, &data->lock);
+
+	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");