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SubjectRe: [PATCH v4] hwmon: Add driver for AMD family 15h processor power information
On Wed, Apr 13, 2011 at 03:06:33PM +0200, Jean Delvare wrote:
> Hi Andreas,
>
> On Fri, 8 Apr 2011 15:54:07 +0200, Andreas Herrmann wrote:
> > From: Andreas Herrmann <andreas.herrmann3@amd.com>
> >
> > This CPU family provides NB register values to gather following
> > TDP information
> >
> > * ProcessorPwrWatts: Specifies in Watts the maximum amount of power
> > the processor can support.
> > * CurrPwrWatts: Specifies in Watts the current amount of power being
> > consumed by the processor.
> >
> > This driver provides
> >
> > * power1_max (ProcessorPwrWatts)
>
> Still questionable whether power1_crit would be more appropriate...

Finally, I've changed it.

> > * power1_input (CurrPwrWatts)
> >
> > Changes from v2:
> > - fix format strings
> > - removed paranoid checks for existense of functions 3 and 5
> > - changed return type of function f15h_power_is_internal_node0
> > - use power1_max instead of power1_cap
> > - use dev_warn instead of WARN_ON
> > - rebased against 2.6.39-rc2
> > - added Documentation/hwmon/f15h_power
> >
> > Changes from v3:
> > - read static power information only once (during driver initialization)
> > - made use of attribute groups
> > - renamed f15h_power to fam15h_power
> >
> > Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
> > ---
> > Documentation/hwmon/fam15h_power | 37 ++++++
> > drivers/hwmon/Kconfig | 10 ++
> > drivers/hwmon/Makefile | 1 +
> > drivers/hwmon/fam15h_power.c | 229 ++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 277 insertions(+), 0 deletions(-)
> > create mode 100644 Documentation/hwmon/fam15h_power
> > create mode 100644 drivers/hwmon/fam15h_power.c
> >
> > At this stage I consider the _max attribute as the right one for
> > reporting ProcessorPwrWatts.
> >
> > Hopefully I've addressed all your coments.
> > Please apply.
>
> It seems I have some more comments, but these are very small things you
> should have no problem addressing quickly:
>
> > diff --git a/Documentation/hwmon/fam15h_power b/Documentation/hwmon/fam15h_power
> > new file mode 100644
> > index 0000000..2f4d291
> > --- /dev/null
> > +++ b/Documentation/hwmon/fam15h_power
> > @@ -0,0 +1,37 @@
> > +Kernel driver fam15h_power
> > +==========================
> > +
> > +Supported chips:
> > +* AMD Family 15h Processors
> > +
> > + Prefix: 'fam15h_power'
> > + Addresses scanned: PCI space
> > + Datasheets:
> > + BIOS and Kernel Developer's Guide (BKDG) For AMD Family 15h Processors
> > + (not yet published)
> > +
> > +Author: Andreas Herrmann <andreas.herrmann3@amd.com>
> > +
> > +Description
> > +-----------
> > +
> > +This driver permits reading of registers providing power information
> > +of AMD Family 15h processors.
> > +
> > +For AMD Family 15h processors the following power values can be
> > +calculated using different processor northbridge function registers:
> > +
> > +* BasePwrWatts: Specifies in watts the maximum amount of power
> > + consumed by the processor for NB and logic external to the core.
> > +* ProcessorPwrWatts: Specifies in watts the maximum amount of power
> > + the processor can support.
> > +* CurrPwrWatts: Specifies in watts the current amount of power being
> > + consumed by the processor.
> > +
> > +This driver provides ProcessorPwrWatts and CurrPwrWatts:
> > +* power1_max (ProcessorPwrWatts)
> > +* power1_input (CurrPwrWatts)
> > +
> > +On multi-node processors the calculated value is for the entire
> > +package and not for a single node. Thus the driver creates sysfs
> > +attributes only for internal node0 of a multi-node processor.
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index 060ef63..fb3e334 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -249,6 +249,16 @@ config SENSORS_K10TEMP
> > This driver can also be built as a module. If so, the module
> > will be called k10temp.
> >
> > +config SENSORS_FAM15H_POWER
> > + tristate "AMD Family 15h processor power"
> > + depends on X86 && PCI
> > + help
> > + If you say yes here you get support for processor power
> > + information of your AMD family 15h CPU.
> > +
> > + This driver can also be built as a module. If so, the module
> > + will be called fam15h_power.
> > +
> > config SENSORS_ASB100
> > tristate "Asus ASB100 Bach"
> > depends on X86 && I2C && EXPERIMENTAL
> > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > index 967d0ea..236d3f9 100644
> > --- a/drivers/hwmon/Makefile
> > +++ b/drivers/hwmon/Makefile
> > @@ -49,6 +49,7 @@ obj-$(CONFIG_SENSORS_EMC2103) += emc2103.o
> > obj-$(CONFIG_SENSORS_F71805F) += f71805f.o
> > obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o
> > obj-$(CONFIG_SENSORS_F75375S) += f75375s.o
> > +obj-$(CONFIG_SENSORS_FAM15H_POWER) += fam15h_power.o
> > obj-$(CONFIG_SENSORS_FSCHMD) += fschmd.o
> > obj-$(CONFIG_SENSORS_G760A) += g760a.o
> > obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o
> > diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
> > new file mode 100644
> > index 0000000..cb6eb99
> > --- /dev/null
> > +++ b/drivers/hwmon/fam15h_power.c
> > @@ -0,0 +1,229 @@
> > +/*
> > + * fam15h_power.c - AMD Family 15h processor power monitoring
> > + *
> > + * Copyright (c) 2011 Advanced Micro Devices, Inc.
> > + * Author: Andreas Herrmann <andreas.herrmann3@amd.com>
> > + *
> > + *
> > + * This driver is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License; either
> > + * version 2 of the License, or (at your option) any later version.
> > + *
> > + * This driver is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> > + * See the GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this driver; if not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include <linux/err.h>
> > +#include <linux/hwmon.h>
> > +#include <linux/hwmon-sysfs.h>
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/pci.h>
> > +#include <linux/bitops.h>
> > +#include <asm/processor.h>
> > +
> > +MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
> > +MODULE_AUTHOR("Andreas Herrmann <andreas.herrmann3@amd.com>");
> > +MODULE_LICENSE("GPL");
> > +
> > +/* D18F3 */
> > +#define REG_NORTHBRIDGE_CAP 0xe8
> > +
> > +/* D18F4 */
> > +#define REG_PROCESSOR_TDP 0x1b8
> > +
> > +/* D18F5 */
> > +#define REG_TDP_RUNNING_AVERAGE 0xe0
> > +#define REG_TDP_LIMIT3 0xe8
> > +
> > +struct fam15h_power_data {
> > + struct device *hwmon_dev;
> > + unsigned int tdp_to_watt;
> > + unsigned int base_tdp;
> > + unsigned int processor_pwr_watts;
>
> watt vs. watts is inconsistent, isn't it?

Changed.

> > +};
> > +
> > +static ssize_t show_power(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + u32 val, tdp_limit, running_avg_range;
> > + s32 running_avg_capture;
> > + u64 curr_pwr_watts;
> > + struct pci_dev *f4 = to_pci_dev(dev);
> > + struct fam15h_power_data *data = pci_get_drvdata(f4);
>
> dev_get_drvdata(dev) would be more efficient.
>
> > +
> > + pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
> > + REG_TDP_RUNNING_AVERAGE, &val);
> > + running_avg_capture = (val >> 4) & 0x3fffff;
> > + running_avg_capture = sign_extend32(running_avg_capture, 22);
> > + running_avg_range = val & 0xf;
> > +
> > + pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
> > + REG_TDP_LIMIT3, &val);
> > +
> > + tdp_limit = val >> 16;
> > + curr_pwr_watts = tdp_limit + data->base_tdp -
>
> Doubled space.

Whoops!

> > + (s32)(running_avg_capture >> (running_avg_range + 1));
> > + curr_pwr_watts *= data->tdp_to_watt;
> > +
> > + /*
> > + * Convert to microWatt
> > + *
> > + * power is in Watt provided as fixed point integer with
> > + * scaling factor 1/(2^16). For conversion we use
> > + * (10^6)/(2^16) = 15625/(2^10)
> > + */
> > + curr_pwr_watts = (curr_pwr_watts * 15625) >> 10;
> > + return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
> > +}
> > +static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
> > +
> > +static ssize_t show_power_max(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct pci_dev *f4 = to_pci_dev(dev);
> > + struct fam15h_power_data *data = pci_get_drvdata(f4);
>
> dev_get_drvdata(dev) would be more efficient (you don't even need f4
> then.)
>
> > + return sprintf(buf, "%u\n", data->processor_pwr_watts);
> > +}
> > +static DEVICE_ATTR(power1_max, S_IRUGO, show_power_max, NULL);
> > +
> > +static ssize_t show_name(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "fam15h_power\n");
> > +}
> > +static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
> > +
> > +static struct attribute *fam15h_power_attrs[] = {
> > + &dev_attr_power1_input.attr,
> > + &dev_attr_power1_max.attr,
> > + &dev_attr_name.attr,
> > + NULL
> > +};
> > +
> > +static struct attribute_group fam15h_power_attr_group = {
>
> Can be made const.

Done this ....
> > + .attrs = fam15h_power_attrs,
> > +};
> > +
> > +static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
> > +{
> > + u32 val;
> > +
> > + pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
> > + REG_NORTHBRIDGE_CAP, &val);
> > + if ((val & BIT(29)) && ((val >> 30) & 3))
> > + return false;
> > +
> > + return true;
> > +}
> > +
> > +static void __devinit fam15h_power_init_data(struct pci_dev *f4,
> > + struct fam15h_power_data *data)
> > +{
> > + u32 val;
> > + u64 tmp;
> > +
> > + pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
> > + data->base_tdp = val >> 16;
> > + tmp = val & 0xffff;
> > +
> > + pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
> > + REG_TDP_LIMIT3, &val);
> > +
> > + data->tdp_to_watt = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
> > + tmp *= data->tdp_to_watt;
> > +
> > + /* result not allowed to be >= 256W */
> > + if ((tmp>>16) >= 256)
>
> Please add spaces around ">>" for consistency.

... and that.

> > + dev_warn(&f4->dev, "Bogus value for ProcessorPwrWatts "
> > + "(processor_pwr_watts>=%u)\n",
> > + (unsigned int) (tmp >> 16));
> > +
> > + /* convert to microWatt */
> > + data->processor_pwr_watts = (tmp * 15625) >> 10;
> > +}
> > +
> > +static int __devinit fam15h_power_probe(struct pci_dev *pdev,
> > + const struct pci_device_id *id)
> > +{
> > + struct fam15h_power_data *data;
> > + struct device *dev;
> > + int err;
> > +
> > + if (!fam15h_power_is_internal_node0(pdev)) {
> > + err = -ENODEV;
> > + goto exit;
> > + }
> > +
> > + data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
> > + if (!data) {
> > + err = -ENOMEM;
> > + goto exit;
> > + }
> > + fam15h_power_init_data(pdev, data);
> > +
> > + dev = &pdev->dev;
> > + err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
> > + if (err)
> > + goto exit_free_data;
> > +
> > + data->hwmon_dev = hwmon_device_register(&pdev->dev);
> > + if (IS_ERR(data->hwmon_dev)) {
> > + err = PTR_ERR(data->hwmon_dev);
> > + goto exit_remove_group;
> > + }
> > + pci_set_drvdata(pdev, data);
>
> This is racy. pci_set_drvdata() should be called before creating the
> sysfs attributes, because the sysfs callbacks need it.

Oops -- fixed.


> > +
> > + return 0;

[snip]


Thanks again for the review


Andreas


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