[PATCH] drm/xe/xe_gt_idle: add debugfs entry for powergating info

Riana Tauro riana.tauro at intel.com
Thu Jul 25 14:00:01 UTC 2024


Hi Michal

Thank you for the review comments

On 7/25/2024 4:09 PM, Michal Wajdeczko wrote:
> 
> 
> On 25.07.2024 09:35, Riana Tauro wrote:
>> Coarse Powergating is a power saving technique where Render and Media
>> can be power-gated independently irrespective of the rest of the GT.
>>
>> For debug purposes, it is useful to expose the powergating information.
>>
>> v2: move to debugfs
>>      add details to commit message
>>      add per-slice status for media
>>      define reg bits in descending order (Matt Roper)
>>
>> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
>> ---
>>   drivers/gpu/drm/xe/regs/xe_gt_regs.h |  8 +++
>>   drivers/gpu/drm/xe/xe_gt_debugfs.c   | 11 ++++
>>   drivers/gpu/drm/xe/xe_gt_idle.c      | 80 ++++++++++++++++++++++++++++
>>   drivers/gpu/drm/xe/xe_gt_idle.h      |  2 +
>>   4 files changed, 101 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> index 8a94a94d2267..fe774d0894fa 100644
>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> @@ -336,6 +336,14 @@
>>   #define   CTC_SOURCE_DIVIDE_LOGIC		REG_BIT(0)
>>   
>>   #define FORCEWAKE_RENDER			XE_REG(0xa278)
>> +
>> +#define POWERGATE_DOMAIN_STATUS			XE_REG(0xa2a0)
>> +#define   MEDIA_SLICE3_AWAKE_STATUS		REG_BIT(4)
>> +#define   MEDIA_SLICE2_AWAKE_STATUS		REG_BIT(3)
>> +#define   MEDIA_SLICE1_AWAKE_STATUS		REG_BIT(2)
>> +#define   RENDER_AWAKE_STATUS			REG_BIT(1)
>> +#define   MEDIA_SLICE0_AWAKE_STATUS		REG_BIT(0)
>> +
>>   #define FORCEWAKE_MEDIA_VDBOX(n)		XE_REG(0xa540 + (n) * 4)
>>   #define FORCEWAKE_MEDIA_VEBOX(n)		XE_REG(0xa560 + (n) * 4)
>>   #define FORCEWAKE_GSC				XE_REG(0xa618)
>> diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
>> index 5e7fd937917a..5ba153aac577 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
>> +++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
>> @@ -15,6 +15,7 @@
>>   #include "xe_ggtt.h"
>>   #include "xe_gt.h"
>>   #include "xe_gt_mcr.h"
>> +#include "xe_gt_idle.h"
>>   #include "xe_gt_sriov_pf_debugfs.h"
>>   #include "xe_gt_sriov_vf_debugfs.h"
>>   #include "xe_gt_topology.h"
>> @@ -107,6 +108,15 @@ static int hw_engines(struct xe_gt *gt, struct drm_printer *p)
>>   	return 0;
>>   }
>>   
>> +static int powergate_info(struct xe_gt *gt, struct drm_printer *p)
>> +{
>> +	xe_pm_runtime_get(gt_to_xe(gt));
>> +	xe_gt_idle_print(gt, p);
> 
> this print function may also return an error

Missed this. Thanks for pointing this. Will fix it
> 
>> +	xe_pm_runtime_put(gt_to_xe(gt));
>> +
>> +	return 0;
>> +}
>> +
>>   static int force_reset(struct xe_gt *gt, struct drm_printer *p)
>>   {
>>   	xe_pm_runtime_get(gt_to_xe(gt));
>> @@ -277,6 +287,7 @@ static const struct drm_info_list debugfs_list[] = {
>>   	{"topology", .show = xe_gt_debugfs_simple_show, .data = topology},
>>   	{"steering", .show = xe_gt_debugfs_simple_show, .data = steering},
>>   	{"ggtt", .show = xe_gt_debugfs_simple_show, .data = ggtt},
>> +	{"powergate_info", .show = xe_gt_debugfs_simple_show, .data = powergate_info},
>>   	{"register-save-restore", .show = xe_gt_debugfs_simple_show, .data = register_save_restore},
>>   	{"workarounds", .show = xe_gt_debugfs_simple_show, .data = workarounds},
>>   	{"pat", .show = xe_gt_debugfs_simple_show, .data = pat},
>> diff --git a/drivers/gpu/drm/xe/xe_gt_idle.c b/drivers/gpu/drm/xe/xe_gt_idle.c
>> index 67aba4140510..c8dd4b732658 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_idle.c
>> +++ b/drivers/gpu/drm/xe/xe_gt_idle.c
>> @@ -145,6 +145,86 @@ void xe_gt_idle_disable_pg(struct xe_gt *gt)
>>   	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
>>   }
>>   
>> +/**
>> + * xe_gt_idle_print - Xe gt idle print
>> + * @gt: GT object
>> + * @p: drm_printer.
>> + *
>> + * This function prints the powergating information
> 
> missing "Return:"
> 
>> + */
>> +int xe_gt_idle_print(struct xe_gt *gt, struct drm_printer *p)
>> +{
>> +	struct xe_device *xe = gt_to_xe(gt);
>> +	u32 pg_enabled, pg_status;
>> +	u32 vcs_mask, vecs_mask;
>> +	int err;
>> +
>> +	if (xe->info.platform == XE_PVC) {
>> +		drm_printf(p, "Power Gating Enabled: no\n");
>> +		return 0;
>> +	}
>> +
>> +	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>> +	if (err)
>> +		return err;
>> +
>> +	pg_enabled = xe_mmio_read32(gt, POWERGATE_ENABLE);
>> +	pg_status = xe_mmio_read32(gt, POWERGATE_DOMAIN_STATUS);
>> +
>> +	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
>> +
>> +	if (gt->info.engine_mask & XE_HW_ENGINE_RCS_MASK) {
>> +		drm_printf(p, "Render Power Gating Enabled: %s\n",
>> +			   str_yes_no(pg_enabled & RENDER_POWERGATE_ENABLE));
>> +
>> +		drm_printf(p, "Render Power Gate Status: %s\n",
>> +			   (pg_status & RENDER_AWAKE_STATUS) ? "Up" : "Down");
> 
> FYI: just posted a patch [1] with the helper that could be used here;
> you may want to start with a local variant until that lands in our tree
> 
> [1]
> https://lore.kernel.org/linux-hardening/20240725101841.574-1-michal.wajdeczko@intel.com/
Sure will do this. Else i could also use str_on_off for now.
> 
>> +	}
>> +
>> +	vcs_mask = xe_hw_engine_mask_per_class(gt, XE_ENGINE_CLASS_VIDEO_DECODE);
>> +	vecs_mask = xe_hw_engine_mask_per_class(gt, XE_ENGINE_CLASS_VIDEO_ENHANCE);
>> +
>> +	/* Print media CPG status only if media is present */
>> +	if (vcs_mask || vecs_mask) {
>> +		drm_printf(p, "Media Power Gating Enabled: %s\n",
>> +			   str_yes_no(pg_enabled & MEDIA_POWERGATE_ENABLE));
>> +
>> +		/*
>> +		 * Media Slices
>> +		 *
>> +		 * Slice 0: VCS0, VCS1, VECS0
>> +		 * Slice 1: VCS2, VCS3, VECS1
>> +		 * Slice 2: VCS4, VCS5, VECS2
>> +		 * Slice 3: VCS6, VCS7, VECS3
>> +		 */
>> +		if (gt->info.engine_mask & (BIT(XE_HW_ENGINE_VCS0)
>> +					    | BIT(XE_HW_ENGINE_VCS1)
>> +					    | BIT(XE_HW_ENGINE_VECS0)))
>> +			drm_printf(p, "Media Slice0 Power Gate Status: %s\n",
>> +				   (pg_status & MEDIA_SLICE0_AWAKE_STATUS) ? "Up" : "Down");
>> +
>> +		if (gt->info.engine_mask & (BIT(XE_HW_ENGINE_VCS2)
>> +					    | BIT(XE_HW_ENGINE_VCS3)
>> +					    | BIT(XE_HW_ENGINE_VECS1)))
>> +			drm_printf(p, "Media Slice1 Power Gate Status: %s\n",
>> +				   (pg_status & MEDIA_SLICE1_AWAKE_STATUS) ? "Up" : "Down");
>> +
>> +		if (gt->info.engine_mask & (BIT(XE_HW_ENGINE_VCS4)
>> +					    | BIT(XE_HW_ENGINE_VCS5)
>> +					    | BIT(XE_HW_ENGINE_VECS2)))
>> +			drm_printf(p, "Media Slice2 Power Gate Status: %s\n",
>> +				   (pg_status & MEDIA_SLICE2_AWAKE_STATUS) ? "Up" : "Down");
>> +
>> +		if (gt->info.engine_mask & (BIT(XE_HW_ENGINE_VCS6)
>> +					    | BIT(XE_HW_ENGINE_VCS7)
>> +					    | BIT(XE_HW_ENGINE_VECS3)))
>> +			drm_printf(p, "Media Slice3 Power Gate Status: %s\n",
>> +				   (pg_status & MEDIA_SLICE3_AWAKE_STATUS) ? "Up" : "Down");
> 
> maybe this could be transformed into some loop?
> 
> 	static const struct {
> 		u64 engines;
> 		u32 status;
> 	} slices[] = {
> 		{ BIT(XE_HW_ENGINE_VCS0) | BIT(XE_HW_ENGINE_VCS1) |
> 		  BIT(XE_HW_ENGINE_VECS0), MEDIA_SLICE0_AWAKE_STATUS },
> 		...
> 	};
> 
> 	if (gt->info.engine_mask & slices[n].engines)
> 		drm_printf(p, "Media Slice%u Power Gate Status: %s\n",
> 			n, str_up_down(pg_status & slices[n].status);
> 
>> +	}
>> +
>> +	return 0;
>> +}
Will try this.

Thank you,
Riana
>> +
>>   static ssize_t name_show(struct device *dev,
>>   			 struct device_attribute *attr, char *buff)
>>   {
>> diff --git a/drivers/gpu/drm/xe/xe_gt_idle.h b/drivers/gpu/drm/xe/xe_gt_idle.h
>> index 554447b5d46d..4b8192d3aee0 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_idle.h
>> +++ b/drivers/gpu/drm/xe/xe_gt_idle.h
>> @@ -8,6 +8,7 @@
>>   
>>   #include "xe_gt_idle_types.h"
>>   
>> +struct drm_printer;
>>   struct xe_gt;
>>   
>>   int xe_gt_idle_init(struct xe_gt_idle *gtidle);
>> @@ -15,5 +16,6 @@ void xe_gt_idle_enable_c6(struct xe_gt *gt);
>>   void xe_gt_idle_disable_c6(struct xe_gt *gt);
>>   void xe_gt_idle_enable_pg(struct xe_gt *gt);
>>   void xe_gt_idle_disable_pg(struct xe_gt *gt);
>> +int xe_gt_idle_print(struct xe_gt *gt, struct drm_printer *p);
>>   
>>   #endif /* _XE_GT_IDLE_H_ */


More information about the Intel-xe mailing list