[PATCH 2/2] RFC drm/xe: Enable Coarse Power Gating

Riana Tauro riana.tauro at intel.com
Wed May 15 07:35:26 UTC 2024


Hi Rodrigo

Thanks for the review

On 5/15/2024 8:41 AM, Rodrigo Vivi wrote:
> On Tue, May 14, 2024 at 12:13:09PM +0530, Riana Tauro wrote:
>> Coarse Power Gating (CPG), where Render and Media can enter C6
>> independent of the remaining GT. Enable render and media
>> power gating.
> 
> Something strange with this phrase...

Will rephrase it
> 
>>
>> Also enable VD HCP/MFX sub-pipe power gating.
>> HCP/MFX power gating is disabled by default, turn it on for
>> the vd units available
> 
> Could be simplified to something like:
> "Enable every power gating that are disabled by default,
> for every unit and sub-pipe available"
> (or something like that).

will change this
> 
>>
>> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
>> ---
>>   drivers/gpu/drm/xe/regs/xe_gt_regs.h |  2 ++
>>   drivers/gpu/drm/xe/xe_gt.c           | 10 +++++++
>>   drivers/gpu/drm/xe/xe_gt_idle.c      | 45 ++++++++++++++++++++++++++--
>>   drivers/gpu/drm/xe/xe_gt_idle.h      |  2 ++
>>   4 files changed, 56 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> index 7c173db7d585..1cb0343ab581 100644
>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> @@ -317,6 +317,8 @@
>>   #define FORCEWAKE_GT				XE_REG(0xa188)
>>   
>>   #define POWERGATE_ENABLE			XE_REG(0xa210)
>> +#define   RENDER_POWERGATE_ENABLE		REG_BIT(0)
>> +#define   MEDIA_POWERGATE_ENABLE		REG_BIT(1)
>>   #define   VDN_HCP_POWERGATE_ENABLE(n)		REG_BIT(3 + 2 * (n))
>>   #define   VDN_MFXVDENC_POWERGATE_ENABLE(n)	REG_BIT(4 + 2 * (n))
>>   
>> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
>> index 36c7b1631fa6..8a09630f5f38 100644
>> --- a/drivers/gpu/drm/xe/xe_gt.c
>> +++ b/drivers/gpu/drm/xe/xe_gt.c
>> @@ -567,6 +567,10 @@ int xe_gt_init(struct xe_gt *gt)
>>   	if (err)
>>   		return err;
>>   
>> +	err = xe_gt_idle_enable_pg(gt);
>> +	if (err)
>> +		return err;
>> +
>>   	return drmm_add_action_or_reset(&gt_to_xe(gt)->drm, gt_fini, gt);
>>   }
>>   
>> @@ -624,6 +628,10 @@ static int do_gt_restart(struct xe_gt *gt)
>>   	if (err)
>>   		return err;
>>   
>> +	err = xe_gt_idle_enable_pg(gt);
>> +	if (err)
>> +		return err;
>> +
>>   	for_each_hw_engine(hwe, gt, id) {
>>   		xe_reg_sr_apply_mmio(&hwe->reg_sr, gt);
>>   		xe_reg_sr_apply_whitelist(hwe);
>> @@ -720,6 +728,8 @@ void xe_gt_suspend_prepare(struct xe_gt *gt)
>>   {
>>   	XE_WARN_ON(xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL));
>>   
>> +	xe_gt_idle_disable_pg(gt);
>> +
> 
> they are not the symmetric equivalents... we should probably find
> a more suitable symmetric place for that.

To disable/enable pg during suspend resume, i can move it to

gt_suspend/gt_resume [But these are also called during runtime pm] /
pm_suspend/pm_resume

> 
>>   	xe_uc_stop_prepare(&gt->uc);
>>   
>>   	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL));
>> diff --git a/drivers/gpu/drm/xe/xe_gt_idle.c b/drivers/gpu/drm/xe/xe_gt_idle.c
>> index 4384f7e80258..f549bbb0e110 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_idle.c
>> +++ b/drivers/gpu/drm/xe/xe_gt_idle.c
>> @@ -12,6 +12,7 @@
>>   #include "xe_gt_sysfs.h"
>>   #include "xe_guc_pc.h"
>>   #include "regs/xe_gt_regs.h"
>> +#include "xe_macros.h"
>>   #include "xe_mmio.h"
>>   #include "xe_pm.h"
>>   
>> @@ -93,6 +94,42 @@ static u64 get_residency_ms(struct xe_gt_idle *gtidle, u64 cur_residency)
>>   	return cur_residency;
>>   }
>>   
>> +int xe_gt_idle_enable_pg(struct xe_gt *gt)
>> +{
>> +	int ret, i;
>> +	u32 pg_enable;
>> +
>> +	xe_device_assert_mem_access(gt_to_xe(gt));
>> +
>> +	pg_enable = RENDER_POWERGATE_ENABLE | MEDIA_POWERGATE_ENABLE;
>> +
>> +	for (i = XE_HW_ENGINE_VCS0; i <= XE_HW_ENGINE_VCS7; i++) {
>> +		if ((gt->info.engine_mask & BIT(i)))
>> +			pg_enable |= (VDN_HCP_POWERGATE_ENABLE(i) |
>> +				      VDN_MFXVDENC_POWERGATE_ENABLE(i));
>> +	}
>> +
>> +	ret = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>> +	if (ret)
>> +		return ret;
>> +
>> +	xe_mmio_write32(gt, POWERGATE_ENABLE, pg_enable);
>> +
>> +	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
>> +
>> +	return 0;
>> +}
>> +
>> +void xe_gt_idle_disable_pg(struct xe_gt *gt)
>> +{
>> +	xe_device_assert_mem_access(gt_to_xe(gt));
>> +	XE_WARN_ON(xe_force_wake_get(gt_to_fw(gt), XE_FW_GT));
>> +
>> +	xe_mmio_write32(gt, POWERGATE_ENABLE, 0);
>> +
>> +	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
>> +}
>> +
>>   static ssize_t name_show(struct device *dev,
>>   			 struct device_attribute *attr, char *buff)
>>   {
>> @@ -145,9 +182,12 @@ static const struct attribute *gt_idle_attrs[] = {
>>   	NULL,
>>   };
>>   
>> -static void gt_idle_sysfs_fini(struct drm_device *drm, void *arg)
>> +static void gt_idle_fini(struct drm_device *drm, void *arg)
>>   {
>>   	struct kobject *kobj = arg;
>> +	struct xe_gt *gt = kobj_to_gt(kobj->parent);
>> +
>> +	xe_gt_idle_disable_pg(gt);
>>   
>>   	sysfs_remove_files(kobj, gt_idle_attrs);
>>   	kobject_put(kobj);
>> @@ -182,7 +222,7 @@ int xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle)
> 
> we should perhaps also change the name of the init function
> to ensure symmetry?
Will rename it. Will also move xe_gt_idle_enable_pg during probe into 
this function.

Thanks
Riana
> 
>>   		return err;
>>   	}
>>   
>> -	return drmm_add_action_or_reset(&xe->drm, gt_idle_sysfs_fini, kobj);
>> +	return drmm_add_action_or_reset(&xe->drm, gt_idle_fini, kobj);
>>   }
>>   
>>   void xe_gt_idle_enable_c6(struct xe_gt *gt)
>> @@ -202,7 +242,6 @@ void xe_gt_idle_disable_c6(struct xe_gt *gt)
>>   	xe_device_assert_mem_access(gt_to_xe(gt));
>>   	xe_force_wake_assert_held(gt_to_fw(gt), XE_FORCEWAKE_ALL);
>>   
>> -	xe_mmio_write32(gt, POWERGATE_ENABLE, 0);
>>   	xe_mmio_write32(gt, RC_CONTROL, 0);
>>   	xe_mmio_write32(gt, RC_STATE, 0);
>>   }
>> diff --git a/drivers/gpu/drm/xe/xe_gt_idle.h b/drivers/gpu/drm/xe/xe_gt_idle.h
>> index 75bd99659b1b..ba7aa36348fc 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_idle.h
>> +++ b/drivers/gpu/drm/xe/xe_gt_idle.h
>> @@ -13,5 +13,7 @@ struct xe_gt;
>>   int xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle);
>>   void xe_gt_idle_enable_c6(struct xe_gt *gt);
>>   void xe_gt_idle_disable_c6(struct xe_gt *gt);
>> +void xe_gt_idle_disable_pg(struct xe_gt *gt);
>> +int  xe_gt_idle_enable_pg(struct xe_gt *gt);
>>   
>>   #endif /* _XE_GT_IDLE_H_ */
>> -- 
>> 2.40.0
>>


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