[PATCH 2/2] drm/i915/mtl: Add C6 residency support for MTL SAMedia

Jani Nikula jani.nikula at linux.intel.com
Tue Sep 20 08:06:52 UTC 2022


On Mon, 19 Sep 2022, "Dixit, Ashutosh" <ashutosh.dixit at intel.com> wrote:
> On Mon, 19 Sep 2022 05:13:18 -0700, Jani Nikula wrote:
>>
>> On Mon, 19 Sep 2022, Badal Nilawar <badal.nilawar at intel.com> wrote:
>> > For MTL SAMedia updated relevant functions and places in the code to get
>> > Media C6 residency.
>> >
>> > v2: Fixed review comments (Ashutosh)
>> >
>> > Cc: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
>> > Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
>> > Cc: Chris Wilson <chris.p.wilson at intel.com>
>> > Signed-off-by: Badal Nilawar <badal.nilawar at intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c | 60 +++++++++++++++++++
>> >  drivers/gpu/drm/i915/gt/intel_gt_regs.h       | 10 ++++
>> >  drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c   |  9 ++-
>> >  drivers/gpu/drm/i915/gt/intel_rc6.c           |  5 +-
>> >  drivers/gpu/drm/i915/gt/selftest_rc6.c        |  9 ++-
>> >  drivers/gpu/drm/i915/i915_pmu.c               |  8 ++-
>> >  6 files changed, 97 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
>> > index 68310881a793..053167b506a9 100644
>> > --- a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
>> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c
>> > @@ -269,6 +269,64 @@ static int ilk_drpc(struct seq_file *m)
>> >	return 0;
>> >  }
>> >
>> > +static int mtl_drpc(struct seq_file *m)
>> > +{
>> > +	struct intel_gt *gt = m->private;
>> > +	struct intel_uncore *uncore = gt->uncore;
>> > +	u32 gt_core_status, rcctl1, global_forcewake;
>> > +	u32 mtl_powergate_enable = 0, mtl_powergate_status = 0;
>> > +	i915_reg_t reg;
>> > +
>> > +	gt_core_status = intel_uncore_read(uncore, MTL_MIRROR_TARGET_WP1);
>> > +
>> > +	global_forcewake = intel_uncore_read(uncore, FORCEWAKE_GT_GEN9);
>> > +
>> > +	rcctl1 = intel_uncore_read(uncore, GEN6_RC_CONTROL);
>> > +	mtl_powergate_enable = intel_uncore_read(uncore, GEN9_PG_ENABLE);
>> > +	mtl_powergate_status = intel_uncore_read(uncore,
>> > +						 GEN9_PWRGT_DOMAIN_STATUS);
>> > +
>> > +	seq_printf(m, "RC6 Enabled: %s\n",
>> > +		   str_yes_no(rcctl1 & GEN6_RC_CTL_RC6_ENABLE));
>> > +	if (gt->type == GT_MEDIA) {
>> > +		seq_printf(m, "Media Well Gating Enabled: %s\n",
>> > +			   str_yes_no(mtl_powergate_enable & GEN9_MEDIA_PG_ENABLE));
>> > +	} else {
>> > +		seq_printf(m, "Render Well Gating Enabled: %s\n",
>> > +			   str_yes_no(mtl_powergate_enable & GEN9_RENDER_PG_ENABLE));
>> > +	}
>> > +
>> > +	seq_puts(m, "Current RC state: ");
>> > +
>> > +	switch ((gt_core_status & MTL_CC_MASK) >> MTL_CC_SHIFT) {
>> > +	case MTL_CC0:
>> > +		seq_puts(m, "on\n");
>> > +		break;
>> > +	case MTL_CC6:
>> > +		seq_puts(m, "RC6\n");
>> > +		break;
>> > +	default:
>> > +		seq_puts(m, "Unknown\n");
>> > +		break;
>> > +	}
>> > +
>> > +	if (gt->type == GT_MEDIA)
>> > +		seq_printf(m, "Media Power Well: %s\n",
>> > +			   (mtl_powergate_status &
>> > +			    GEN9_PWRGT_MEDIA_STATUS_MASK) ? "Up" : "Down");
>> > +	else
>> > +		seq_printf(m, "Render Power Well: %s\n",
>> > +			   (mtl_powergate_status &
>> > +			    GEN9_PWRGT_RENDER_STATUS_MASK) ? "Up" : "Down");
>> > +
>> > +	reg = (gt->type == GT_MEDIA) ? MTL_MEDIA_MC6 : GEN6_GT_GFX_RC6;
>> > +	print_rc6_res(m, "RC6 residency since boot:", reg);
>>
>> Cc: Tvrtko, Joonas, Rodrigo
>>
>
> Hi Jani,
>
>> IMO the register is not a good abstraction to build interfaces on. I see
>> that this is not where the idea is introduced, but it'll probably get
>> you in trouble later on.
>
> By "this is not where the idea is introduced" are you referring to what we
> did here:
>
> https://patchwork.freedesktop.org/patch/502372/?series=108091&rev=5
>
> in intel_gt_perf_limit_reasons_reg()?
>
> Or, should we follow the schema of centralizing the register selection
> depending on gt type in a single function here too (since this register
> selection is repeated throughout this patch)?

I'm looking at print_rc6_res(), for example.

It takes the register, reads it, and also passes the register around,
eventually to intel_rc6_residency_ns(). That does magic on the register
offset, so it assumes a certain multi-register layout, and relative from
GEN6_GT_GFX_RC6_LOCKED. Then it assumes the register contents are
different on different platforms.

So why did we pass around the register to begin with? The knowledge
about the register offsets and contents are spread around. What if
another platform gets added with a different register contents or layout
or offsets?

Registers are a really low level of abstraction, and IMO usually should
not be passed around like this.


BR,
Jani.


>
> Thanks.
> --
> Ashutosh
>
>
>
>>
>> BR,
>> Jani.
>>
>> > +
>> > +	seq_printf(m, "Global Forcewake Requests: 0x%x\n", global_forcewake);
>> > +
>> > +	return fw_domains_show(m, NULL);
>> > +}
>> > +
>> >  static int drpc_show(struct seq_file *m, void *unused)
>> >  {
>> >	struct intel_gt *gt = m->private;
>> > @@ -279,6 +337,8 @@ static int drpc_show(struct seq_file *m, void *unused)
>> >	with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
>> >		if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
>> >			err = vlv_drpc(m);
>> > +		else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
>> > +			err = mtl_drpc(m);
>> >		else if (GRAPHICS_VER(i915) >= 6)
>> >			err = gen6_drpc(m);
>> >		else
>> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
>> > index 7819d32db956..8a56fd873228 100644
>> > --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
>> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
>> > @@ -1517,6 +1517,16 @@
>> >   */
>> >  #define MTL_MIRROR_TARGET_WP1          _MMIO(0x0C60)
>> >  #define   MTL_CAGF_MASK                REG_GENMASK(8, 0)
>> > +#define   MTL_CC0                      0x0
>> > +#define   MTL_CC6                      0x3
>> > +#define   MTL_CC_SHIFT                 9
>> > +#define   MTL_CC_MASK                  (0xf << MTL_CC_SHIFT)
>> > +
>> > +/*
>> > + * MTL: This register contains the total MC6 residency time that SAMedia was
>> > + * since boot
>> > + */
>> > +#define MTL_MEDIA_MC6                          _MMIO(0x138048)
>> >
>> >  #define GEN11_GT_INTR_DW(x)			_MMIO(0x190018 + ((x) * 4))
>> >  #define   GEN11_CSME				(31)
>> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
>> > index 54deae45d81f..7ab1d776673a 100644
>> > --- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
>> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
>> > @@ -123,7 +123,14 @@ static ssize_t rc6_enable_show(struct device *dev,
>> >
>> >  static u32 __rc6_residency_ms_show(struct intel_gt *gt)
>> >  {
>> > -	return get_residency(gt, GEN6_GT_GFX_RC6);
>> > +	i915_reg_t reg;
>> > +
>> > +	if (gt->type == GT_MEDIA)
>> > +		reg = MTL_MEDIA_MC6;
>> > +	else
>> > +		reg = GEN6_GT_GFX_RC6;
>> > +
>> > +	return get_residency(gt, reg);
>> >  }
>> >
>> >  static ssize_t rc6_residency_ms_show(struct device *dev,
>> > diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c
>> > index f8d0523f4c18..26f71f7f07c6 100644
>> > --- a/drivers/gpu/drm/i915/gt/intel_rc6.c
>> > +++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
>> > @@ -745,6 +745,7 @@ u64 intel_rc6_residency_ns(struct intel_rc6 *rc6, const i915_reg_t reg)
>> >	unsigned long flags;
>> >	unsigned int i;
>> >	u32 mul, div;
>> > +	i915_reg_t base;
>> >
>> >	if (!rc6->supported)
>> >		return 0;
>> > @@ -756,8 +757,10 @@ u64 intel_rc6_residency_ns(struct intel_rc6 *rc6, const i915_reg_t reg)
>> >	 * other so we can use the relative address, compared to the smallest
>> >	 * one as the index into driver storage.
>> >	 */
>> > +	base = (rc6_to_gt(rc6)->type == GT_MEDIA) ?
>> > +	       MTL_MEDIA_MC6 : GEN6_GT_GFX_RC6_LOCKED;
>> >	i = (i915_mmio_reg_offset(reg) -
>> > -	     i915_mmio_reg_offset(GEN6_GT_GFX_RC6_LOCKED)) / sizeof(u32);
>> > +	     i915_mmio_reg_offset(base)) / sizeof(u32);
>> >	if (drm_WARN_ON_ONCE(&i915->drm, i >= ARRAY_SIZE(rc6->cur_residency)))
>> >		return 0;
>> >
>> > diff --git a/drivers/gpu/drm/i915/gt/selftest_rc6.c b/drivers/gpu/drm/i915/gt/selftest_rc6.c
>> > index 8c70b7e12074..28c6a4b6b8d1 100644
>> > --- a/drivers/gpu/drm/i915/gt/selftest_rc6.c
>> > +++ b/drivers/gpu/drm/i915/gt/selftest_rc6.c
>> > @@ -15,11 +15,18 @@
>> >
>> >  static u64 rc6_residency(struct intel_rc6 *rc6)
>> >  {
>> > +	struct intel_gt *gt = rc6_to_gt(rc6);
>> > +	i915_reg_t reg;
>> >	u64 result;
>> >
>> >	/* XXX VLV_GT_MEDIA_RC6? */
>> >
>> > -	result = intel_rc6_residency_ns(rc6, GEN6_GT_GFX_RC6);
>> > +	if (gt->type == GT_MEDIA)
>> > +		reg = MTL_MEDIA_MC6;
>> > +	else
>> > +		reg = GEN6_GT_GFX_RC6;
>> > +
>> > +	result = intel_rc6_residency_ns(rc6, reg);
>> >	if (HAS_RC6p(rc6_to_i915(rc6)))
>> >		result += intel_rc6_residency_ns(rc6, GEN6_GT_GFX_RC6p);
>> >	if (HAS_RC6pp(rc6_to_i915(rc6)))
>> > diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
>> > index 958b37123bf1..6ec139668641 100644
>> > --- a/drivers/gpu/drm/i915/i915_pmu.c
>> > +++ b/drivers/gpu/drm/i915/i915_pmu.c
>> > @@ -146,9 +146,15 @@ static bool pmu_needs_timer(struct i915_pmu *pmu, bool gpu_active)
>> >  static u64 __get_rc6(struct intel_gt *gt)
>> >  {
>> >	struct drm_i915_private *i915 = gt->i915;
>> > +	i915_reg_t reg;
>> >	u64 val;
>> >
>> > -	val = intel_rc6_residency_ns(&gt->rc6, GEN6_GT_GFX_RC6);
>> > +	if (gt->type == GT_MEDIA)
>> > +		reg = MTL_MEDIA_MC6;
>> > +	else
>> > +		reg = GEN6_GT_GFX_RC6;
>> > +
>> > +	val = intel_rc6_residency_ns(&gt->rc6, reg);
>> >
>> >	if (HAS_RC6p(i915))
>> >		val += intel_rc6_residency_ns(&gt->rc6, GEN6_GT_GFX_RC6p);
>>
>> --
>> Jani Nikula, Intel Open Source Graphics Center

-- 
Jani Nikula, Intel Open Source Graphics Center


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