[Intel-gfx] [PATCH 1/7] drm/i915/hwmon: Add HWMON infrastructure
Nilawar, Badal
badal.nilawar at intel.com
Tue Aug 23 08:42:14 UTC 2022
On 19-08-2022 16:05, Jani Nikula wrote:
> On Fri, 19 Aug 2022, Badal Nilawar <badal.nilawar at intel.com> wrote:
>> From: Dale B Stimson <dale.b.stimson at intel.com>
>>
>> The i915 HWMON module will be used to expose voltage, power and energy
>> values for dGfx. Here we set up i915 hwmon infrastructure including i915
>> hwmon registration, basic data structures and functions.
>>
>> v2:
>> - Create HWMON infra patch (Ashutosh)
>> - Fixed review comments (Jani)
>> - Remove "select HWMON" from i915/Kconfig (Jani)
>> v3: Use hwm_ prefix for static functions (Ashutosh)
>> v4: s/#ifdef CONFIG_HWMON/#if IS_REACHABLE(CONFIG_HWMON)/ since the former
>> doesn't work if hwmon is compiled as a module (Guenter)
>
> Is this really what we want to do?
>
> In my books, it's a misconfiguration to have CONFIG_HWMON=m with
> CONFIG_DRM_I915=y. That's really the problematic combo, not just
> CONFIG_HWMON=m, right? Why do we allow it at the kconfig level, and then
> have ugly hacks around it at the code level? Especially as
> CONFIG_DRM_I915=y should really be thought of as a corner case.
>
> So why not do this in i915 Kconfig:
>
> config DRM_I915
> ...
> depends on HWMON || HWMON=n
With this change I am getting recursive dependancy error when I run make
oldconfig
badal at bnilawar-desk1:~/workspace/wp3/drm-tip$ make oldconfig
HOSTCC scripts/basic/fixdep
HOSTCC scripts/kconfig/conf.o
HOSTCC scripts/kconfig/confdata.o
HOSTCC scripts/kconfig/expr.o
LEX scripts/kconfig/lexer.lex.c
YACC scripts/kconfig/parser.tab.[ch]
HOSTCC scripts/kconfig/lexer.lex.o
HOSTCC scripts/kconfig/menu.o
HOSTCC scripts/kconfig/parser.tab.o
HOSTCC scripts/kconfig/preprocess.o
HOSTCC scripts/kconfig/symbol.o
HOSTCC scripts/kconfig/util.o
HOSTLD scripts/kconfig/conf
drivers/gpu/drm/i915/Kconfig:2:error: recursive dependency detected!
drivers/gpu/drm/i915/Kconfig:2: symbol DRM_I915 depends on HWMON
drivers/hwmon/Kconfig:6: symbol HWMON is selected by EEEPC_LAPTOP
drivers/platform/x86/Kconfig:332: symbol EEEPC_LAPTOP depends on INPUT
drivers/input/Kconfig:8: symbol INPUT is selected by DRM_I915
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"
make[1]: *** [scripts/kconfig/Makefile:77: oldconfig] Error 1
make: *** [Makefile:632: oldconfig] Error 2
>
> Which rejects the CONFIG_HWMON=m && CONFIG_DRM_I915=y combo.
>
>>
>> Cc: Guenter Roeck <linux at roeck-us.net>
>> Signed-off-by: Dale B Stimson <dale.b.stimson at intel.com>
>> Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
>> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
>> Signed-off-by: Badal Nilawar <badal.nilawar at intel.com>
>> ---
>> drivers/gpu/drm/i915/Makefile | 3 +
>> drivers/gpu/drm/i915/i915_driver.c | 7 ++
>> drivers/gpu/drm/i915/i915_drv.h | 2 +
>> drivers/gpu/drm/i915/i915_hwmon.c | 135 +++++++++++++++++++++++++++++
>> drivers/gpu/drm/i915/i915_hwmon.h | 20 +++++
>> 5 files changed, 167 insertions(+)
>> create mode 100644 drivers/gpu/drm/i915/i915_hwmon.c
>> create mode 100644 drivers/gpu/drm/i915/i915_hwmon.h
>>
>> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>> index 522ef9b4aff3..2b235f747490 100644
>> --- a/drivers/gpu/drm/i915/Makefile
>> +++ b/drivers/gpu/drm/i915/Makefile
>> @@ -208,6 +208,9 @@ i915-y += gt/uc/intel_uc.o \
>> # graphics system controller (GSC) support
>> i915-y += gt/intel_gsc.o
>>
>> +# graphics hardware monitoring (HWMON) support
>> +i915-$(CONFIG_HWMON) += i915_hwmon.o
>
> Moreover, this builds i915_hwmon.o as part of i915.ko (or kernel as it's
> builtin) even if we can't use it!
For CONFIG_HWMON=m && CONFIG_DRM_I915=y combo i915_hwmon.o didn't get
build. It is only getting build for below combos
CONFIG_HWMON=m && CONFIG_DRM_I915=y
CONFIG_HWMON=m && CONFIG_DRM_I915=m
CONFIG_HWMON=y && CONFIG_DRM_I915=m
Regards,
Badal
>
>
> BR,
> Jani.
>
>
>> +
>> # modesetting core code
>> i915-y += \
>> display/hsw_ips.o \
>> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
>> index deb8a8b76965..62340cd01dde 100644
>> --- a/drivers/gpu/drm/i915/i915_driver.c
>> +++ b/drivers/gpu/drm/i915/i915_driver.c
>> @@ -80,6 +80,7 @@
>> #include "i915_drm_client.h"
>> #include "i915_drv.h"
>> #include "i915_getparam.h"
>> +#include "i915_hwmon.h"
>> #include "i915_ioc32.h"
>> #include "i915_ioctl.h"
>> #include "i915_irq.h"
>> @@ -736,6 +737,9 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
>>
>> intel_gt_driver_register(to_gt(dev_priv));
>>
>> +#if IS_REACHABLE(CONFIG_HWMON)
>> + i915_hwmon_register(dev_priv);
>> +#endif
>> intel_display_driver_register(dev_priv);
>>
>> intel_power_domains_enable(dev_priv);
>> @@ -762,6 +766,9 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
>>
>> intel_display_driver_unregister(dev_priv);
>>
>> +#if IS_REACHABLE(CONFIG_HWMON)
>> + i915_hwmon_unregister(dev_priv);
>> +#endif
>> intel_gt_driver_unregister(to_gt(dev_priv));
>>
>> i915_perf_unregister(dev_priv);
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 086bbe8945d6..d437d588dec9 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -705,6 +705,8 @@ struct drm_i915_private {
>>
>> struct i915_perf perf;
>>
>> + struct i915_hwmon *hwmon;
>> +
>> /* Abstract the submission mechanism (legacy ringbuffer or execlists) away */
>> struct intel_gt gt0;
>>
>> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
>> new file mode 100644
>> index 000000000000..5b80a0f024f0
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
>> @@ -0,0 +1,135 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/types.h>
>> +
>> +#include "i915_drv.h"
>> +#include "i915_hwmon.h"
>> +#include "intel_mchbar_regs.h"
>> +
>> +struct hwm_reg {
>> +};
>> +
>> +struct hwm_drvdata {
>> + struct i915_hwmon *hwmon;
>> + struct intel_uncore *uncore;
>> + struct device *hwmon_dev;
>> + char name[12];
>> +};
>> +
>> +struct i915_hwmon {
>> + struct hwm_drvdata ddat;
>> + struct mutex hwmon_lock; /* counter overflow logic and rmw */
>> + struct hwm_reg rg;
>> +};
>> +
>> +static const struct hwmon_channel_info *hwm_info[] = {
>> + NULL
>> +};
>> +
>> +static umode_t
>> +hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
>> + u32 attr, int channel)
>> +{
>> + switch (type) {
>> + default:
>> + return 0;
>> + }
>> +}
>> +
>> +static int
>> +hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>> + int channel, long *val)
>> +{
>> + switch (type) {
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +}
>> +
>> +static int
>> +hwm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>> + int channel, long val)
>> +{
>> + switch (type) {
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +}
>> +
>> +static const struct hwmon_ops hwm_ops = {
>> + .is_visible = hwm_is_visible,
>> + .read = hwm_read,
>> + .write = hwm_write,
>> +};
>> +
>> +static const struct hwmon_chip_info hwm_chip_info = {
>> + .ops = &hwm_ops,
>> + .info = hwm_info,
>> +};
>> +
>> +static void
>> +hwm_get_preregistration_info(struct drm_i915_private *i915)
>> +{
>> +}
>> +
>> +void i915_hwmon_register(struct drm_i915_private *i915)
>> +{
>> + struct device *dev = i915->drm.dev;
>> + struct i915_hwmon *hwmon;
>> + struct device *hwmon_dev;
>> + struct hwm_drvdata *ddat;
>> +
>> + /* hwmon is available only for dGfx */
>> + if (!IS_DGFX(i915))
>> + return;
>> +
>> + hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
>> + if (!hwmon)
>> + return;
>> +
>> + i915->hwmon = hwmon;
>> + mutex_init(&hwmon->hwmon_lock);
>> + ddat = &hwmon->ddat;
>> +
>> + ddat->hwmon = hwmon;
>> + ddat->uncore = &i915->uncore;
>> + snprintf(ddat->name, sizeof(ddat->name), "i915");
>> +
>> + hwm_get_preregistration_info(i915);
>> +
>> + /* hwmon_dev points to device hwmon<i> */
>> + hwmon_dev = hwmon_device_register_with_info(dev, ddat->name,
>> + ddat,
>> + &hwm_chip_info,
>> + NULL);
>> + if (IS_ERR(hwmon_dev)) {
>> + mutex_destroy(&hwmon->hwmon_lock);
>> + i915->hwmon = NULL;
>> + kfree(hwmon);
>> + return;
>> + }
>> +
>> + ddat->hwmon_dev = hwmon_dev;
>> +}
>> +
>> +void i915_hwmon_unregister(struct drm_i915_private *i915)
>> +{
>> + struct i915_hwmon *hwmon;
>> + struct hwm_drvdata *ddat;
>> +
>> + hwmon = fetch_and_zero(&i915->hwmon);
>> + if (!hwmon)
>> + return;
>> +
>> + ddat = &hwmon->ddat;
>> + if (ddat->hwmon_dev)
>> + hwmon_device_unregister(ddat->hwmon_dev);
>> +
>> + mutex_destroy(&hwmon->hwmon_lock);
>> + kfree(hwmon);
>> +}
>> diff --git a/drivers/gpu/drm/i915/i915_hwmon.h b/drivers/gpu/drm/i915/i915_hwmon.h
>> new file mode 100644
>> index 000000000000..921ae76099d3
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/i915_hwmon.h
>> @@ -0,0 +1,20 @@
>> +/* SPDX-License-Identifier: MIT */
>> +
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#ifndef __I915_HWMON_H__
>> +#define __I915_HWMON_H__
>> +
>> +#include <linux/device.h>
>> +#include <linux/mutex.h>
>> +#include <linux/types.h>
>> +#include "i915_reg.h"
>> +
>> +struct drm_i915_private;
>> +
>> +void i915_hwmon_register(struct drm_i915_private *i915);
>> +void i915_hwmon_unregister(struct drm_i915_private *i915);
>> +
>> +#endif /* __I915_HWMON_H__ */
>
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