On Thu, Sep 06, 2012 at 01:54:10PM -0700, Ben Widawsky wrote:
> From: Jesse Barnes <jbarnes at virtuousgeek.org>
>
> On SNB and IVB, there's an MSR (also exposed through MCHBAR) we can use
> to read out the amount of energy used over time. Expose this in sysfs
> to make it easy to do power comparisons with different configurations.
>
> If the platform supports it, the file will show up under the
> drm/card0/power subdirectory of the PCI device in sysfs as gt_energy_uJ.
> The value in the file is a running total of energy (in microjoules)
> consumed by the graphics device.
>
> v2: move to sysfs (Ben, Daniel)
> expose a simple value (Chris)
> drop unrelated hunk (Ben)
>
> Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
>
> v3: by Ben
> Tied it into existing rc6 sysfs entries and named that a more generic
> "power attrs." Fixed rebase conflicts.
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 2 ++
> drivers/gpu/drm/i915/i915_sysfs.c | 25 +++++++++++++++++++++++--
> 2 files changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index d0b60f2..0e34f5f 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1242,6 +1242,8 @@
> #define CLKCFG_MEM_800 (3 << 4)
> #define CLKCFG_MEM_MASK (7 << 4)
>
> +#define SECP_NRG_STTS (MCHBAR_MIRROR_BASE_SNB + 0x592c)
> +
> #define TSC1 0x11001
> #define TSE (1<<0)
> #define TR1 0x11006
> diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
> index e3a31ae..6bbc9af 100644
> --- a/drivers/gpu/drm/i915/i915_sysfs.c
> +++ b/drivers/gpu/drm/i915/i915_sysfs.c
> @@ -76,22 +76,43 @@ show_rc6pp_ms(struct device *kdev, struct device_attribute *attr, char *buf)
> return snprintf(buf, PAGE_SIZE, "%u", rc6pp_residency);
> }
>
> +#define MSR_IA32_PACKAGE_POWER_SKU_UNIT 0x00000606
> +
> +static ssize_t
> +show_gt_energy_uJ(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct drm_minor *dminor = container_of(dev, struct drm_minor, kdev);
> + struct drm_i915_private *dev_priv = dminor->dev->dev_private;
> + u64 ppsu;
> + u32 val, units;
> +
> + rdmsrl(MSR_IA32_PACKAGE_POWER_SKU_UNIT, ppsu);
> +
> + ppsu = (ppsu & 0x1f00) >> 8;
> + units = 1000000 / (1 << ppsu); /* convert to uJ */
> + val = I915_READ(SECP_NRG_STTS);
> +
> + return snprintf(buf, PAGE_SIZE, "%u", val * units);
Besides that this could overflow it also introduces rounding errors that
accumulate. I guess we need a 64 mul+div here, like in the residency
counters.
-Daniel
> +}
> +
> static DEVICE_ATTR(rc6_enable, S_IRUGO, show_rc6_mask, NULL);
> static DEVICE_ATTR(rc6_residency_ms, S_IRUGO, show_rc6_ms, NULL);
> static DEVICE_ATTR(rc6p_residency_ms, S_IRUGO, show_rc6p_ms, NULL);
> static DEVICE_ATTR(rc6pp_residency_ms, S_IRUGO, show_rc6pp_ms, NULL);
> +static DEVICE_ATTR(gt_energy_uJ, S_IRUGO, show_gt_energy_uJ, NULL);
>
> -static struct attribute *rc6_attrs[] = {
> +static struct attribute *power_attrs[] = {
> &dev_attr_rc6_enable.attr,
> &dev_attr_rc6_residency_ms.attr,
> &dev_attr_rc6p_residency_ms.attr,
> &dev_attr_rc6pp_residency_ms.attr,
> + &dev_attr_gt_energy_uJ.attr,
> NULL
> };
>
> static struct attribute_group rc6_attr_group = {
> .name = power_group_name,
> - .attrs = rc6_attrs
> + .attrs = power_attrs
> };
> #endif
>
> --
> 1.7.12
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
