[RFC 2/2] drm/amd/pm: Add support for reacting to platform profile notification
Alex Deucher
alexdeucher at gmail.com
Wed Nov 10 17:51:22 UTC 2021
On Wed, Nov 10, 2021 at 12:31 PM Limonciello, Mario
<Mario.Limonciello at amd.com> wrote:
>
> [Public]
>
>
>
> > I don't think we want to force the performance level. This interface
> forces various fixed clock configurations for debugging and profiling.
>
> Ah got it.
>
>
>
> >I think what we'd want to select here is the power profile (see
> amdgpu_set_pp_power_profile_mode()). For this interface you can
> select various profiles (BOOTUP_DEFAULT, 3D_FULL_SCREEN, POWER_SAVING,
> VIDEO, VR, COMPUTE, etc.). These still use dynamic power management,
> but they adjust the heuristics used by the GPU to select power states
> so the GPU performance ramps up/down more or less aggressively.
>
>
>
> Which profile mapping you think make sense?
>
> My guess would be:
>
> “BOOTUP_DEFAULT” for balanced
>
> “POWER_SAVING” for low-power
>
> “3D_FULL_SCREEN” for performance
Yeah, that is what I was thinking.
>
>
>
> Since recently we removed that interface for YC, and some earlier APUs don’t do as much with it.
>
> So I wonder if this is only really valuable to do this callback for !APU.
>
Yes, I think so. I think for APUs this will be handled under the
covers in the platform firmware going forward.
>
>
> > I feel it's better to leave to platform vendors. For ex: for APU cases they may have implementations in which their BIOSes talk to PMFW and this might be driving something else here.
>
>
>
> Even if changing the heuristic for workload as Alex suggested?
>
>
>
> > Also, not sure how to handle a case like, say a laptop with Intel CPU and AMD dgpu.
>
>
>
> I was actually thinking this approach where there are platform profile callbacks is best because of that specifically.
>
> It would allow an Intel CPU system to have a platform profile driver implemented by the OEM, but then still notify amdgpu dGPU to tune for power saving or performance workload.
>
Right, a user could still adjust these via the existing sysfs
interface today, this just makes it a little more automatic. I guess
it depends whether we want to couple them or not.
Alex
>
>
> From: Lazar, Lijo <Lijo.Lazar at amd.com>
> Sent: Wednesday, November 10, 2021 10:05
> To: Alex Deucher <alexdeucher at gmail.com>; Limonciello, Mario <Mario.Limonciello at amd.com>
> Cc: amd-gfx list <amd-gfx at lists.freedesktop.org>
> Subject: Re: [RFC 2/2] drm/amd/pm: Add support for reacting to platform profile notification
>
>
>
> [Public]
>
>
>
> I feel it's better to leave to platform vendors. For ex: for APU cases they may have implementations in which their BIOSes talk to PMFW and this might be driving something else here.
>
>
>
> Also, not sure how to handle a case like, say a laptop with Intel CPU and AMD dgpu.
>
>
>
> Thanks,
> Lijo
>
>
>
> ________________________________
>
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> on behalf of Alex Deucher <alexdeucher at gmail.com>
> Sent: Wednesday, 10 November 2021, 8:44 pm
> To: Limonciello, Mario
> Cc: amd-gfx list
> Subject: Re: [RFC 2/2] drm/amd/pm: Add support for reacting to platform profile notification
>
>
>
> On Wed, Nov 10, 2021 at 1:24 AM Mario Limonciello
> <mario.limonciello at amd.com> wrote:
> >
> > Various drivers provide platform profile support to let users set a hint
> > in their GUI whether they want to run in a high performance, low battery
> > life or balanced configuration.
> >
> > Drivers that provide this typically work with the firmware on their system
> > to configure hardware. In the case of AMDGPU however, the notification
> > path doesn't come through firmware and can instead be provided directly
> > to the driver from a notification chain.
> >
> > Use the information of the newly selected profile to tweak
> > `dpm_force_performance_level` to that profile IFF the user hasn't manually
> > selected `manual` or any other `profile_*` options.
>
> I don't think we want to force the performance level. This interface
> forces various fixed clock configurations for debugging and profiling.
> I think what we'd want to select here is the power profile (see
> amdgpu_set_pp_power_profile_mode()). For this interface you can
> select various profiles (BOOTUP_DEFAULT, 3D_FULL_SCREEN, POWER_SAVING,
> VIDEO, VR, COMPUTE, etc.). These still use dynamic power management,
> but they adjust the heuristics used by the GPU to select power states
> so the GPU performance ramps up/down more or less aggressively.
>
> Alex
>
> >
> > Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 +
> > drivers/gpu/drm/amd/pm/amdgpu_pm.c | 105 +++++++++++++++++++++++-----
> > 2 files changed, 90 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > index b85b67a88a3d..27b0be23b6ac 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > @@ -1097,6 +1097,9 @@ struct amdgpu_device {
> >
> > struct amdgpu_reset_control *reset_cntl;
> > uint32_t ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
> > +
> > + /* platform profile notifications */
> > + struct notifier_block platform_profile_notifier;
> > };
> >
> > static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)
> > diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > index 41472ed99253..33fc52b90d4c 100644
> > --- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > +++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > @@ -32,6 +32,7 @@
> > #include <linux/hwmon.h>
> > #include <linux/hwmon-sysfs.h>
> > #include <linux/nospec.h>
> > +#include <linux/platform_profile.h>
> > #include <linux/pm_runtime.h>
> > #include <asm/processor.h>
> > #include "hwmgr.h"
> > @@ -200,6 +201,33 @@ static ssize_t amdgpu_set_power_dpm_state(struct device *dev,
> > return count;
> > }
> >
> > +static int amdgpu_get_forced_level(struct device *dev, enum amd_dpm_forced_level *level)
> > +{
> > + struct drm_device *ddev = dev_get_drvdata(dev);
> > + struct amdgpu_device *adev = drm_to_adev(ddev);
> > + int ret;
> > +
> > + if (amdgpu_in_reset(adev))
> > + return -EPERM;
> > + if (adev->in_suspend && !adev->in_runpm)
> > + return -EPERM;
> > +
> > + ret = pm_runtime_get_sync(ddev->dev);
> > + if (ret < 0) {
> > + pm_runtime_put_autosuspend(ddev->dev);
> > + return ret;
> > + }
> > +
> > + if (adev->powerplay.pp_funcs->get_performance_level)
> > + *level = amdgpu_dpm_get_performance_level(adev);
> > + else
> > + *level = adev->pm.dpm.forced_level;
> > +
> > + pm_runtime_mark_last_busy(ddev->dev);
> > + pm_runtime_put_autosuspend(ddev->dev);
> > +
> > + return 0;
> > +}
> >
> > /**
> > * DOC: power_dpm_force_performance_level
> > @@ -264,29 +292,13 @@ static ssize_t amdgpu_get_power_dpm_force_performance_level(struct device *dev,
> > struct device_attribute *attr,
> > char *buf)
> > {
> > - struct drm_device *ddev = dev_get_drvdata(dev);
> > - struct amdgpu_device *adev = drm_to_adev(ddev);
> > enum amd_dpm_forced_level level = 0xff;
> > int ret;
> >
> > - if (amdgpu_in_reset(adev))
> > - return -EPERM;
> > - if (adev->in_suspend && !adev->in_runpm)
> > - return -EPERM;
> > + ret = amdgpu_get_forced_level(dev, &level);
> >
> > - ret = pm_runtime_get_sync(ddev->dev);
> > - if (ret < 0) {
> > - pm_runtime_put_autosuspend(ddev->dev);
> > + if (ret < 0)
> > return ret;
> > - }
> > -
> > - if (adev->powerplay.pp_funcs->get_performance_level)
> > - level = amdgpu_dpm_get_performance_level(adev);
> > - else
> > - level = adev->pm.dpm.forced_level;
> > -
> > - pm_runtime_mark_last_busy(ddev->dev);
> > - pm_runtime_put_autosuspend(ddev->dev);
> >
> > return sysfs_emit(buf, "%s\n",
> > (level == AMD_DPM_FORCED_LEVEL_AUTO) ? "auto" :
> > @@ -405,6 +417,59 @@ static ssize_t amdgpu_set_power_dpm_force_performance_level(struct device *dev,
> > return count;
> > }
> >
> > +static void amdgpu_update_profile(struct device *dev, enum platform_profile_option *profile)
> > +{
> > + enum amd_dpm_forced_level level;
> > + const char *str;
> > + int ret;
> > +
> > + ret = amdgpu_get_forced_level(dev, &level);
> > + if (ret < 0)
> > + return;
> > +
> > + /* only update profile if we're in fixed modes right now that need updating */
> > + switch (level) {
> > + case AMD_DPM_FORCED_LEVEL_LOW:
> > + if (*profile < PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + case AMD_DPM_FORCED_LEVEL_HIGH:
> > + if (*profile > PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + case AMD_DPM_FORCED_LEVEL_AUTO:
> > + if (*profile == PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + default:
> > + dev_dbg(dev, "refusing to update amdgpu profile from %d\n", level);
> > + return;
> > + }
> > + if (*profile > PLATFORM_PROFILE_BALANCED)
> > + str = "high";
> > + else if (*profile < PLATFORM_PROFILE_BALANCED)
> > + str = "low";
> > + else
> > + str = "auto";
> > +
> > + dev_dbg(dev, "updating platform profile to %s\n", str);
> > + amdgpu_set_power_dpm_force_performance_level(dev, NULL, str, 0);
> > +}
> > +
> > +static int amdgpu_platform_profile_notifier_call(struct notifier_block *nb,
> > + unsigned long action, void *data)
> > +{
> > + if (action == PLATFORM_PROFILE_CHANGED) {
> > + enum platform_profile_option *profile = data;
> > + struct amdgpu_device *adev;
> > +
> > + adev = container_of(nb, struct amdgpu_device, platform_profile_notifier);
> > + amdgpu_update_profile(adev->dev, profile);
> > + }
> > +
> > + return NOTIFY_OK;
> > +}
> > +
> > static ssize_t amdgpu_get_pp_num_states(struct device *dev,
> > struct device_attribute *attr,
> > char *buf)
> > @@ -3506,6 +3571,9 @@ int amdgpu_pm_sysfs_init(struct amdgpu_device *adev)
> > if (ret)
> > return ret;
> >
> > + adev->platform_profile_notifier.notifier_call = amdgpu_platform_profile_notifier_call;
> > + platform_profile_register_notifier(&adev->platform_profile_notifier);
> > +
> > adev->pm.sysfs_initialized = true;
> >
> > return 0;
> > @@ -3519,6 +3587,7 @@ void amdgpu_pm_sysfs_fini(struct amdgpu_device *adev)
> > if (adev->pm.int_hwmon_dev)
> > hwmon_device_unregister(adev->pm.int_hwmon_dev);
> >
> > + platform_profile_unregister_notifier(&adev->platform_profile_notifier);
> > amdgpu_device_attr_remove_groups(adev, &adev->pm.pm_attr_list);
> > }
> >
> > --
> > 2.25.1
> >
>
>
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