Re: [PATCH v9] drm/i915/icl: Check for fused-off VDBOX and VEBOX instances

Sagar Arun Kamble
2018-02-22T06:17:29Z

Looks good to me. Few cosmetic changes suggested below. With those
addressed:
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>

On 2/22/2018 5:05 AM, Oscar Mateo wrote:
> In Gen11, the Video Decode engines (aka VDBOX, aka VCS, aka BSD) and the
> Video Enhancement engines (aka VEBOX, aka VECS) could be fused off. Also,
> each VDBOX and VEBOX has its own power well, which only exist if the related
> engine exists in the HW.
>
> Unfortunately, we have a Catch-22 situation going on: we need the blitter
> forcewake to read the register with the fuse info, but we cannot initialize
> the forcewake domains without knowin about the engines present in the HW.
*knowing
> We workaround this problem by pruning the forcewake domains after reading
> the fuse information.
This line can be re-framed like:
"We workaround this problem by allowing initialization of all forcewake
domains and then pruning the fused off forcewake domains
based on fuse info which can be read acquiring blitter forcewake"
>
> Bspec: 20680
>
> v2: We were shifting incorrectly for vebox disable (Vinay)
>
> v3: Assert mmio is ready and warn if we have attempted to initialize
> forcewake for fused-off engines (Paulo)
>
> v4:
> - Use INTEL_GEN in new code (Tvrtko)
> - Shorter local variable (Tvrtko, Michal)
> - Keep "if (!...) continue" style (Tvrtko)
> - No unnecessary BUG_ON (Tvrtko)
> - WARN_ON and cleanup if wrong mask (Tvrtko, Michal)
> - Use I915_READ_FW (Michal)
> - Use I915_MAX_VCS/VECS macros (Michal)
>
> v5: Rebased by Rodrigo fixing conflicts on top of:
> commit 33def1ff7b0 ("drm/i915: Simplify intel_engines_init")
>
> v6: Fix v5. Remove info->num_rings. (by Oscar)
>
> v7: Rebase (Rodrigo).
>
> v8:
> - s/intel_device_info_fused_off_engines/intel_device_info_init_mmio (Chris)
> - Make vdbox_disable & vebox_disable local variables (Chris)
>
> v9:
> - Move function declaration to intel_device_info.h (Michal)
> - Missing indent in bit fields definitions (Michal)
> - When RC6 is enabled by BIOS, the fuse register cannot be read until
> the blitter powerwell is awake. Shuffle where the fuse is read, prune
> the forcewake domains after the fact and change the commit message
> accordingly (Vinay, Sagar, Chris).
>
> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 4 +++
> drivers/gpu/drm/i915/i915_reg.h | 5 +++
> drivers/gpu/drm/i915/intel_device_info.c | 47 +++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_device_info.h | 1 +
> drivers/gpu/drm/i915/intel_uncore.c | 55 ++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_uncore.h | 1 +
> 6 files changed, 113 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index d09f8e6..2269b56 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1031,6 +1031,10 @@ static int i915_driver_init_mmio(struct drm_i915_private *dev_priv)
>
> intel_uncore_init(dev_priv);
>
> + intel_device_info_init_mmio(dev_priv);
> +
> + intel_uncore_prune(dev_priv);
> +
> intel_uc_init_mmio(dev_priv);
>
> ret = intel_engines_init_mmio(dev_priv);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 784d79c..e6a0d84 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2854,6 +2854,11 @@ enum i915_power_well_id {
> #define GEN10_EU_DISABLE3 _MMIO(0x9140)
> #define GEN10_EU_DIS_SS_MASK 0xff
>
> +#define GEN11_GT_VEBOX_VDBOX_DISABLE _MMIO(0x9140)
> +#define GEN11_GT_VDBOX_DISABLE_MASK 0xff
> +#define GEN11_GT_VEBOX_DISABLE_SHIFT 16
> +#define GEN11_GT_VEBOX_DISABLE_MASK (0xff << GEN11_GT_VEBOX_DISABLE_SHIFT)
> +
> #define GEN6_BSD_SLEEP_PSMI_CONTROL _MMIO(0x12050)
> #define GEN6_BSD_SLEEP_MSG_DISABLE (1 << 0)
> #define GEN6_BSD_SLEEP_FLUSH_DISABLE (1 << 2)
> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> index 9352f34..70ea654 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.c
> +++ b/drivers/gpu/drm/i915/intel_device_info.c
> @@ -595,3 +595,50 @@ void intel_driver_caps_print(const struct intel_driver_caps *caps,
> {
> drm_printf(p, "scheduler: %x\n", caps->scheduler);
> }
> +
> +/*
> + * Determine which engines are fused off in our particular hardware. Since the
> + * fuse register is in the blitter powerwell, we need forcewake to be ready at
> + * this point (but later we need to prune the forcewake domains for engines that
> + * are indeed fused off).
> + */
> +void intel_device_info_init_mmio(struct drm_i915_private *dev_priv)
> +{
> + struct intel_device_info *info = mkwrite_device_info(dev_priv);
> + u8 vdbox_disable, vebox_disable;
> + u32 media_fuse;
> + int i;
> +
> + if (INTEL_GEN(dev_priv) < 11)
> + return;
> +
> + media_fuse = I915_READ(GEN11_GT_VEBOX_VDBOX_DISABLE);
> +
> + vdbox_disable = media_fuse & GEN11_GT_VDBOX_DISABLE_MASK;
> + vebox_disable = (media_fuse & GEN11_GT_VEBOX_DISABLE_MASK) >>
> + GEN11_GT_VEBOX_DISABLE_SHIFT;
> +
> + DRM_DEBUG_DRIVER("vdbox disable: %04x\n", vdbox_disable);
> + for (i = 0; i < I915_MAX_VCS; i++) {
> + if (!HAS_ENGINE(dev_priv, _VCS(i)))
> + continue;
> +
> + if (!(BIT(i) & vdbox_disable))
> + continue;
> +
> + info->ring_mask &= ~ENGINE_MASK(_VCS(i));
> + DRM_DEBUG_DRIVER("vcs%u fused off\n", i);
> + }
> +
> + DRM_DEBUG_DRIVER("vebox disable: %04x\n", vebox_disable);
> + for (i = 0; i < I915_MAX_VECS; i++) {
> + if (!HAS_ENGINE(dev_priv, _VECS(i)))
> + continue;
> +
> + if (!(BIT(i) & vebox_disable))
> + continue;
> +
> + info->ring_mask &= ~ENGINE_MASK(_VECS(i));
> + DRM_DEBUG_DRIVER("vecs%u fused off\n", i);
> + }
> +}
> diff --git a/drivers/gpu/drm/i915/intel_device_info.h b/drivers/gpu/drm/i915/intel_device_info.h
> index 4c6f83b..2233a2f 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.h
> +++ b/drivers/gpu/drm/i915/intel_device_info.h
> @@ -187,6 +187,7 @@ void intel_device_info_dump_flags(const struct intel_device_info *info,
> struct drm_printer *p);
> void intel_device_info_dump_runtime(const struct intel_device_info *info,
> struct drm_printer *p);
May be we need to add extra line to differentiate from
"device_info_*_runtime_*" function declarations.
> +void intel_device_info_init_mmio(struct drm_i915_private *dev_priv);
>
> void intel_driver_caps_print(const struct intel_driver_caps *caps,
> struct drm_printer *p);
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index 5ae9a62..5de0d26 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -56,6 +56,10 @@
> fw_domain_reset(struct drm_i915_private *i915,
> const struct intel_uncore_forcewake_domain *d)
> {
> + /*
> + * We don't really know if the powerwell for the forcewake domain we are
> + * trying to reset here does exist at this point, so no waiting for acks
> + */
We should also add that this applies to ICL.
> __raw_i915_write32(i915, d->reg_set, i915->uncore.fw_reset);
> }
>
> @@ -1251,6 +1255,23 @@ static void fw_domain_init(struct drm_i915_private *dev_priv,
> fw_domain_reset(dev_priv, d);
> }
>
> +static void fw_domain_fini(struct drm_i915_private *dev_priv,
> + enum forcewake_domain_id domain_id)
> +{
> + struct intel_uncore_forcewake_domain *d;
> +
> + if (WARN_ON(domain_id >= FW_DOMAIN_ID_COUNT))
> + return;
> +
> + d = &dev_priv->uncore.fw_domain[domain_id];
> +
> + WARN_ON(d->wake_count);
> + WARN_ON(hrtimer_cancel(&d->timer));
> + memset(d, 0, sizeof(*d));
> +
> + dev_priv->uncore.fw_domains &= ~BIT(domain_id);
> +}
> +
> static void intel_uncore_fw_domains_init(struct drm_i915_private *dev_priv)
> {
> if (INTEL_GEN(dev_priv) <= 5 || intel_vgpu_active(dev_priv))
> @@ -1432,6 +1453,40 @@ void intel_uncore_init(struct drm_i915_private *dev_priv)
> &dev_priv->uncore.pmic_bus_access_nb);
> }
>
> +/*
> + * We might have detected that some engines are fused off after we initialized
> + * the forcewake domains. Prune them, to make sure they only reference existing
> + * engines.
> + */
> +void intel_uncore_prune(struct drm_i915_private *dev_priv)
> +{
> + if (INTEL_GEN(dev_priv) >= 11) {
> + enum forcewake_domains fw_domains = dev_priv->uncore.fw_domains;
> + enum forcewake_domain_id domain_id;
> + int i;
> +
> + for (i = 0; i < I915_MAX_VCS; i++) {
> + domain_id = FW_DOMAIN_ID_MEDIA_VDBOX0 + i;
> +
> + if (HAS_ENGINE(dev_priv, _VCS(i)))
> + continue;
> +
> + if (fw_domains & BIT(domain_id))
fw_domains check seems redundant as it is initialized based on HAS_ENGINE.
we can just have
if (!HAS_ENGINE(dev_priv, _VCS(i)))
fw_domain_fini(dev_priv, domain_id);
> + fw_domain_fini(dev_priv, domain_id);
> + }
> +
> + for (i = 0; i < I915_MAX_VECS; i++) {
> + domain_id = FW_DOMAIN_ID_MEDIA_VEBOX0 + i;
> +
> + if (HAS_ENGINE(dev_priv, _VECS(i)))
> + continue;
> +
> + if (fw_domains & BIT(domain_id))
> + fw_domain_fini(dev_priv, domain_id);
> + }
> + }
> +}
> +
> void intel_uncore_fini(struct drm_i915_private *dev_priv)
> {
> /* Paranoia: make sure we have disabled everything before we exit. */
> diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h
> index 53ef77d..28feabf 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.h
> +++ b/drivers/gpu/drm/i915/intel_uncore.h
> @@ -129,6 +129,7 @@ struct intel_uncore {
>
> void intel_uncore_sanitize(struct drm_i915_private *dev_priv);
> void intel_uncore_init(struct drm_i915_private *dev_priv);
> +void intel_uncore_prune(struct drm_i915_private *dev_priv);
> bool intel_uncore_unclaimed_mmio(struct drm_i915_private *dev_priv);
> bool intel_uncore_arm_unclaimed_mmio_detection(struct drm_i915_private *dev_priv);
> void intel_uncore_fini(struct drm_i915_private *dev_priv);

--
Thanks,
Sagar