Re: [PATCH 4/5] drm/i915: Use only blitter forcewake

Kamble, Sagar A
2015-09-12T18:15:12Z

On 9/11/2015 7:32 PM, Ville Syrjälä wrote:
> On Fri, Sep 11, 2015 at 07:24:31PM +0530, Kamble, Sagar A wrote:
>>
>> On 9/11/2015 7:07 PM, Ville Syrjälä wrote:
>>> On Sun, Aug 23, 2015 at 05:52:50PM +0530, Sagar Arun Kamble wrote:
>>>> Coarse power gating is disabled prior to BXT B0 and till SKL E0,
>>>> hence even for render and media well registers blitter forcewake request
>>>> need to be used.
>>>>
>>>> Change-Id: Ibfa8abf02b4d27ca1fcd68fc9e98c2daade7c286
>>>> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>>>> ---
>>>> drivers/gpu/drm/i915/i915_debugfs.c | 5 +++-
>>>> drivers/gpu/drm/i915/i915_drv.h | 1 +
>>>> drivers/gpu/drm/i915/intel_uncore.c | 53 ++++++++++++++++++++++++++++++-------
>>>> 3 files changed, 48 insertions(+), 11 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>>>> index 7a28de5..8eea452 100644
>>>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>>>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>>>> @@ -1509,7 +1509,10 @@ static int gen6_drpc_info(struct seq_file *m)
>>>> intel_runtime_pm_get(dev_priv);
>>>>
>>>> spin_lock_irq(&dev_priv->uncore.lock);
>>>> - forcewake_count = dev_priv->uncore.fw_domain[FW_DOMAIN_ID_RENDER].wake_count;
>>>> + if (use_blitter_forcewake(dev))
>>>> + forcewake_count = dev_priv->uncore.fw_domain[FW_DOMAIN_ID_BLITTER].wake_count;
>>>> + else
>>>> + forcewake_count = dev_priv->uncore.fw_domain[FW_DOMAIN_ID_RENDER].wake_count;
>>>> spin_unlock_irq(&dev_priv->uncore.lock);
>>>>
>>>> if (forcewake_count) {
>>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>>>> index e0f3f05..c127175 100644
>>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>>> @@ -2691,6 +2691,7 @@ extern void intel_uncore_check_errors(struct drm_device *dev);
>>>> extern void intel_uncore_fini(struct drm_device *dev);
>>>> extern void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore);
>>>> const char *intel_uncore_forcewake_domain_to_str(const enum forcewake_domain_id id);
>>>> +bool use_blitter_forcewake(struct drm_device *dev);
>>>> void intel_uncore_forcewake_get(struct drm_i915_private *dev_priv,
>>>> enum forcewake_domains domains);
>>>> void intel_uncore_forcewake_put(struct drm_i915_private *dev_priv,
>>>> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
>>>> index 2df03b1..b7b6612 100644
>>>> --- a/drivers/gpu/drm/i915/intel_uncore.c
>>>> +++ b/drivers/gpu/drm/i915/intel_uncore.c
>>>> @@ -63,6 +63,19 @@ intel_uncore_forcewake_domain_to_str(const enum forcewake_domain_id id)
>>>> return "unknown";
>>>> }
>>>>
>>>> +bool use_blitter_forcewake(struct drm_device *dev)
>>>> +{
>>>> + /*
>>>> + * Due to WaRsDisableCoarsePowerGating, Only blitter forcewake need to
>>>> + * be used on platforms previous to BXT B0 and until SKL E0.
>>>> + */
>>> You say only blitter forcewake need be used. OK, but how does that imply
>>> that you need to grab the blitter forcewake for render/media wells as
>>> well?
>> Ok. I need to reword the commit message. Change is to grab blitter fw
>> for all register accesses in GT.
> Where is that documented BTW? I couldn't find anything solid.
This is not documented as part of WaRsDisableCoarsePowerGating.
But if Coarse Power Gating is disabled it is as good as legacy RC6 flow
like in HSW/BDW.
And hence we need to take blitter forcewake for all accesses.
>>>> + if ((IS_BROXTON(dev) && (INTEL_REVID(dev) < BXT_REVID_B0)) ||
>>>> + (IS_SKYLAKE(dev) && (INTEL_REVID(dev) <= SKL_REVID_E0)))
>>>> + return true;
>>>> + else
>>>> + return false;
>>>> +}
>>>> +
>>>> static void
>>>> assert_device_not_suspended(struct drm_i915_private *dev_priv)
>>>> {
>>>> @@ -129,6 +142,9 @@ fw_domains_get(struct drm_i915_private *dev_priv, enum forcewake_domains fw_doma
>>>> struct intel_uncore_forcewake_domain *d;
>>>> enum forcewake_domain_id id;
>>>>
>>>> + WARN_ON(use_blitter_forcewake(dev_priv->dev) &&
>>>> + (fw_domains & ~FORCEWAKE_BLITTER));
>>>> +
>>>> for_each_fw_domain_mask(d, fw_domains, dev_priv, id) {
>>>> fw_domain_wait_ack_clear(d);
>>>> fw_domain_get(d);
>>>> @@ -142,6 +158,9 @@ fw_domains_put(struct drm_i915_private *dev_priv, enum forcewake_domains fw_doma
>>>> struct intel_uncore_forcewake_domain *d;
>>>> enum forcewake_domain_id id;
>>>>
>>>> + WARN_ON(use_blitter_forcewake(dev_priv->dev) &&
>>>> + (fw_domains & ~FORCEWAKE_BLITTER));
>>>> +
>>>> for_each_fw_domain_mask(d, fw_domains, dev_priv, id) {
>>>> fw_domain_put(d);
>>>> fw_domain_posting_read(d);
>>>> @@ -313,6 +332,11 @@ void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
>>>> if (fw)
>>>> dev_priv->uncore.funcs.force_wake_put(dev_priv, fw);
>>>>
>>>> + if (use_blitter_forcewake(dev) && !restore) {
>>>> + __raw_i915_write32(dev_priv, FORCEWAKE_RENDER_GEN9, _MASKED_BIT_DISABLE(0xffff));
>>>> + __raw_i915_write32(dev_priv, FORCEWAKE_MEDIA_GEN9, _MASKED_BIT_DISABLE(0xffff));
>>>> + }
>>>> +
>>>> fw_domains_reset(dev_priv, FORCEWAKE_ALL);
>>>>
>>>> if (restore) { /* If reset with a user forcewake, try to restore */
>>>> @@ -780,8 +804,11 @@ gen9_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
>>>> fw_engine = FORCEWAKE_RENDER | FORCEWAKE_MEDIA; \
>>>> else \
>>>> fw_engine = FORCEWAKE_BLITTER; \
>>>> - if (fw_engine) \
>>>> + if (fw_engine) { \
>>>> + if (use_blitter_forcewake(dev_priv->dev)) \
>>>> + fw_engine = FORCEWAKE_BLITTER; \
>>>> __force_wake_get(dev_priv, fw_engine); \
>>>> + } \
>>>> val = __raw_i915_read##x(dev_priv, reg); \
>>>> GEN6_READ_FOOTER; \
>>>> }
>>>> @@ -994,8 +1021,11 @@ gen9_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, \
>>>> fw_engine = FORCEWAKE_RENDER | FORCEWAKE_MEDIA; \
>>>> else \
>>>> fw_engine = FORCEWAKE_BLITTER; \
>>>> - if (fw_engine) \
>>>> + if (fw_engine) { \
>>>> + if (use_blitter_forcewake(dev_priv->dev)) \
>>>> + fw_engine = FORCEWAKE_BLITTER; \
>>>> __force_wake_get(dev_priv, fw_engine); \
>>>> + } \
>>>> __raw_i915_write##x(dev_priv, reg, val); \
>>>> GEN6_WRITE_FOOTER; \
>>>> }
>>>> @@ -1106,14 +1136,17 @@ static void intel_uncore_fw_domains_init(struct drm_device *dev)
>>>> if (IS_GEN9(dev)) {
>>>> dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
>>>> dev_priv->uncore.funcs.force_wake_put = fw_domains_put;
>>>> - fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
>>>> - FORCEWAKE_RENDER_GEN9,
>>>> - FORCEWAKE_ACK_RENDER_GEN9);
>>>> - fw_domain_init(dev_priv, FW_DOMAIN_ID_BLITTER,
>>>> - FORCEWAKE_BLITTER_GEN9,
>>>> - FORCEWAKE_ACK_BLITTER_GEN9);
>>>> - fw_domain_init(dev_priv, FW_DOMAIN_ID_MEDIA,
>>>> - FORCEWAKE_MEDIA_GEN9, FORCEWAKE_ACK_MEDIA_GEN9);
>>>> + if (!use_blitter_forcewake(dev)) {
>>>> + fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
>>>> + FORCEWAKE_RENDER_GEN9,
>>>> + FORCEWAKE_ACK_RENDER_GEN9);
>>>> + fw_domain_init(dev_priv, FW_DOMAIN_ID_MEDIA,
>>>> + FORCEWAKE_MEDIA_GEN9,
>>>> + FORCEWAKE_ACK_MEDIA_GEN9);
>>>> + }
>>>> + fw_domain_init(dev_priv, FW_DOMAIN_ID_BLITTER,
>>>> + FORCEWAKE_BLITTER_GEN9,
>>>> + FORCEWAKE_ACK_BLITTER_GEN9);
>>>> } else if (IS_VALLEYVIEW(dev)) {
>>>> dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
>>>> if (!IS_CHERRYVIEW(dev))
>>>> --
>>>> 1.9.1
>>>>
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