[v3,13/15] drm/i915/rkl: Handle HTI
diff mbox series

Message ID 20200603211529.3005059-14-matthew.d.roper@intel.com
State New
Headers show
Series
  • Remaining RKL patches
Related show

Commit Message

Matt Roper June 3, 2020, 9:15 p.m. UTC
If HTI (also sometimes called HDPORT) is enabled at startup, it may be
using some of the PHYs and DPLLs making them unavailable for general
usage.  Let's read out the HDPORT_STATE register and avoid making use of
resources that HTI is already using.

v2:
 - Fix minor checkpatch warnings

Bspec: 49189
Bspec: 53707
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c  | 30 ++++++++++++++++---
 drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 21 +++++++++++++
 drivers/gpu/drm/i915/display/intel_dpll_mgr.h |  1 +
 drivers/gpu/drm/i915/i915_drv.h               |  3 ++
 drivers/gpu/drm/i915/i915_reg.h               |  6 ++++
 5 files changed, 57 insertions(+), 4 deletions(-)

Comments

Ville Syrjälä June 4, 2020, 4:59 p.m. UTC | #1
On Wed, Jun 03, 2020 at 02:15:27PM -0700, Matt Roper wrote:
> If HTI (also sometimes called HDPORT) is enabled at startup, it may be

whatis HTI?

> using some of the PHYs and DPLLs making them unavailable for general
> usage.  Let's read out the HDPORT_STATE register and avoid making use of
> resources that HTI is already using.
> 
> v2:
>  - Fix minor checkpatch warnings
> 
> Bspec: 49189
> Bspec: 53707
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c  | 30 ++++++++++++++++---
>  drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 21 +++++++++++++
>  drivers/gpu/drm/i915/display/intel_dpll_mgr.h |  1 +
>  drivers/gpu/drm/i915/i915_drv.h               |  3 ++
>  drivers/gpu/drm/i915/i915_reg.h               |  6 ++++
>  5 files changed, 57 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index bcc6dc4e321b..cdd84a419cf7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -46,6 +46,7 @@
>  #include "display/intel_ddi.h"
>  #include "display/intel_dp.h"
>  #include "display/intel_dp_mst.h"
> +#include "display/intel_dpll_mgr.h"
>  #include "display/intel_dsi.h"
>  #include "display/intel_dvo.h"
>  #include "display/intel_gmbus.h"
> @@ -16817,6 +16818,13 @@ static void intel_pps_init(struct drm_i915_private *dev_priv)
>  	intel_pps_unlock_regs_wa(dev_priv);
>  }
>  
> +static bool hti_uses_phy(u32 hdport_state, enum phy phy)
> +{
> +	return hdport_state & HDPORT_ENABLED &&
> +		(hdport_state & HDPORT_PHY_USED_DP(phy) ||
> +		 hdport_state & HDPORT_PHY_USED_HDMI(phy));
> +}
> +
>  static void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  {
>  	struct intel_encoder *encoder;
> @@ -16828,10 +16836,22 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  		return;
>  
>  	if (IS_ROCKETLAKE(dev_priv)) {
> -		intel_ddi_init(dev_priv, PORT_A);
> -		intel_ddi_init(dev_priv, PORT_B);
> -		intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
> -		intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
> +		/*
> +		 * If HTI (aka HDPORT) is enabled at boot, it may have taken
> +		 * over some of the PHYs and made them unavailable to the
> +		 * driver.  In that case we should skip initializing the
> +		 * corresponding outputs.
> +		 */
> +		u32 hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
> +
> +		if (!hti_uses_phy(hdport_state, PHY_A))
> +			intel_ddi_init(dev_priv, PORT_A);
> +		if (!hti_uses_phy(hdport_state, PHY_B))
> +			intel_ddi_init(dev_priv, PORT_B);
> +		if (!hti_uses_phy(hdport_state, PHY_C))
> +			intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
> +		if (!hti_uses_phy(hdport_state, PHY_D))
> +			intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
>  	} else if (INTEL_GEN(dev_priv) >= 12) {
>  		intel_ddi_init(dev_priv, PORT_A);
>  		intel_ddi_init(dev_priv, PORT_B);
> @@ -18379,6 +18399,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  
>  	intel_dpll_readout_hw_state(dev_priv);
>  
> +	dev_priv->hti_pll_mask = intel_get_hti_plls(dev_priv);
> +
>  	for_each_intel_encoder(dev, encoder) {
>  		pipe = 0;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> index b5f4d4cef682..6f59f9ec453b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> @@ -265,6 +265,24 @@ void intel_disable_shared_dpll(const struct intel_crtc_state *crtc_state)
>  	mutex_unlock(&dev_priv->dpll.lock);
>  }
>  
> +/*
> + * HTI (aka HDPORT) may be using some of the platform's PLL's, making them
> + * unavailable for use.
> + */
> +u32 intel_get_hti_plls(struct drm_i915_private *dev_priv)
> +{
> +	u32 hdport_state;
> +
> +	if (!IS_ROCKETLAKE(dev_priv))
> +		return 0;
> +
> +	hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
> +	if (!(hdport_state & HDPORT_ENABLED))
> +		return 0;
> +
> +	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, hdport_state);
> +}
> +
>  static struct intel_shared_dpll *
>  intel_find_shared_dpll(struct intel_atomic_state *state,
>  		       const struct intel_crtc *crtc,
> @@ -280,6 +298,9 @@ intel_find_shared_dpll(struct intel_atomic_state *state,
>  
>  	drm_WARN_ON(&dev_priv->drm, dpll_mask & ~(BIT(I915_NUM_PLLS) - 1));
>  
> +	/* Eliminate DPLLs from consideration if reserved by HTI */
> +	dpll_mask &= ~dev_priv->hti_pll_mask;
> +
>  	for_each_set_bit(i, &dpll_mask, I915_NUM_PLLS) {
>  		pll = &dev_priv->dpll.shared_dplls[i];
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> index 5d9a2bc371e7..ac2238646fe7 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> @@ -390,6 +390,7 @@ void intel_shared_dpll_swap_state(struct intel_atomic_state *state);
>  void intel_shared_dpll_init(struct drm_device *dev);
>  void intel_dpll_readout_hw_state(struct drm_i915_private *dev_priv);
>  void intel_dpll_sanitize_state(struct drm_i915_private *dev_priv);
> +u32 intel_get_hti_plls(struct drm_i915_private *dev_priv);
>  
>  void intel_dpll_dump_hw_state(struct drm_i915_private *dev_priv,
>  			      const struct intel_dpll_hw_state *hw_state);
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index e99255e17eb7..668b3c9cf3ae 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1037,6 +1037,9 @@ struct drm_i915_private {
>  
>  	struct intel_l3_parity l3_parity;
>  
> +	/* Mask of PLLs reserved for use by HTI and unavailable to driver. */
> +	u32 hti_pll_mask;
> +
>  	/*
>  	 * edram size in MB.
>  	 * Cannot be determined by PCIID. You must always read a register.
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 85137d268c4a..b9faf0f978cf 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2906,6 +2906,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>  #define MBUS_BBOX_CTL_S1		_MMIO(0x45040)
>  #define MBUS_BBOX_CTL_S2		_MMIO(0x45044)
>  
> +#define HDPORT_STATE			_MMIO(0x45050)
> +#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(14, 12)
> +#define   HDPORT_PHY_USED_DP(phy)	REG_BIT(2*(phy) + 2)
> +#define   HDPORT_PHY_USED_HDMI(phy)	REG_BIT(2*(phy) + 1)
> +#define   HDPORT_ENABLED		REG_BIT(0)
> +
>  /* Make render/texture TLB fetches lower priorty than associated data
>   *   fetches. This is not turned on by default
>   */
> -- 
> 2.24.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Matt Roper June 4, 2020, 10:55 p.m. UTC | #2
On Thu, Jun 04, 2020 at 07:59:55PM +0300, Ville Syrjälä wrote:
> On Wed, Jun 03, 2020 at 02:15:27PM -0700, Matt Roper wrote:
> > If HTI (also sometimes called HDPORT) is enabled at startup, it may be
> 
> whatis HTI?

That's not really clear in the bspec or any other documents I've seen.
It sounds like its something setup by the boot firmware that can
potentially steal PLL and PHYs away.  Driver-wise there doesn't seem to
be much we need to do other than avoid using the reserved resources,
sort of like how we avoid using fused off units.


Matt

> 
> > using some of the PHYs and DPLLs making them unavailable for general
> > usage.  Let's read out the HDPORT_STATE register and avoid making use of
> > resources that HTI is already using.
> > 
> > v2:
> >  - Fix minor checkpatch warnings
> > 
> > Bspec: 49189
> > Bspec: 53707
> > Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c  | 30 ++++++++++++++++---
> >  drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 21 +++++++++++++
> >  drivers/gpu/drm/i915/display/intel_dpll_mgr.h |  1 +
> >  drivers/gpu/drm/i915/i915_drv.h               |  3 ++
> >  drivers/gpu/drm/i915/i915_reg.h               |  6 ++++
> >  5 files changed, 57 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index bcc6dc4e321b..cdd84a419cf7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -46,6 +46,7 @@
> >  #include "display/intel_ddi.h"
> >  #include "display/intel_dp.h"
> >  #include "display/intel_dp_mst.h"
> > +#include "display/intel_dpll_mgr.h"
> >  #include "display/intel_dsi.h"
> >  #include "display/intel_dvo.h"
> >  #include "display/intel_gmbus.h"
> > @@ -16817,6 +16818,13 @@ static void intel_pps_init(struct drm_i915_private *dev_priv)
> >  	intel_pps_unlock_regs_wa(dev_priv);
> >  }
> >  
> > +static bool hti_uses_phy(u32 hdport_state, enum phy phy)
> > +{
> > +	return hdport_state & HDPORT_ENABLED &&
> > +		(hdport_state & HDPORT_PHY_USED_DP(phy) ||
> > +		 hdport_state & HDPORT_PHY_USED_HDMI(phy));
> > +}
> > +
> >  static void intel_setup_outputs(struct drm_i915_private *dev_priv)
> >  {
> >  	struct intel_encoder *encoder;
> > @@ -16828,10 +16836,22 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
> >  		return;
> >  
> >  	if (IS_ROCKETLAKE(dev_priv)) {
> > -		intel_ddi_init(dev_priv, PORT_A);
> > -		intel_ddi_init(dev_priv, PORT_B);
> > -		intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
> > -		intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
> > +		/*
> > +		 * If HTI (aka HDPORT) is enabled at boot, it may have taken
> > +		 * over some of the PHYs and made them unavailable to the
> > +		 * driver.  In that case we should skip initializing the
> > +		 * corresponding outputs.
> > +		 */
> > +		u32 hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
> > +
> > +		if (!hti_uses_phy(hdport_state, PHY_A))
> > +			intel_ddi_init(dev_priv, PORT_A);
> > +		if (!hti_uses_phy(hdport_state, PHY_B))
> > +			intel_ddi_init(dev_priv, PORT_B);
> > +		if (!hti_uses_phy(hdport_state, PHY_C))
> > +			intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
> > +		if (!hti_uses_phy(hdport_state, PHY_D))
> > +			intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
> >  	} else if (INTEL_GEN(dev_priv) >= 12) {
> >  		intel_ddi_init(dev_priv, PORT_A);
> >  		intel_ddi_init(dev_priv, PORT_B);
> > @@ -18379,6 +18399,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
> >  
> >  	intel_dpll_readout_hw_state(dev_priv);
> >  
> > +	dev_priv->hti_pll_mask = intel_get_hti_plls(dev_priv);
> > +
> >  	for_each_intel_encoder(dev, encoder) {
> >  		pipe = 0;
> >  
> > diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> > index b5f4d4cef682..6f59f9ec453b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> > @@ -265,6 +265,24 @@ void intel_disable_shared_dpll(const struct intel_crtc_state *crtc_state)
> >  	mutex_unlock(&dev_priv->dpll.lock);
> >  }
> >  
> > +/*
> > + * HTI (aka HDPORT) may be using some of the platform's PLL's, making them
> > + * unavailable for use.
> > + */
> > +u32 intel_get_hti_plls(struct drm_i915_private *dev_priv)
> > +{
> > +	u32 hdport_state;
> > +
> > +	if (!IS_ROCKETLAKE(dev_priv))
> > +		return 0;
> > +
> > +	hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
> > +	if (!(hdport_state & HDPORT_ENABLED))
> > +		return 0;
> > +
> > +	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, hdport_state);
> > +}
> > +
> >  static struct intel_shared_dpll *
> >  intel_find_shared_dpll(struct intel_atomic_state *state,
> >  		       const struct intel_crtc *crtc,
> > @@ -280,6 +298,9 @@ intel_find_shared_dpll(struct intel_atomic_state *state,
> >  
> >  	drm_WARN_ON(&dev_priv->drm, dpll_mask & ~(BIT(I915_NUM_PLLS) - 1));
> >  
> > +	/* Eliminate DPLLs from consideration if reserved by HTI */
> > +	dpll_mask &= ~dev_priv->hti_pll_mask;
> > +
> >  	for_each_set_bit(i, &dpll_mask, I915_NUM_PLLS) {
> >  		pll = &dev_priv->dpll.shared_dplls[i];
> >  
> > diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> > index 5d9a2bc371e7..ac2238646fe7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> > @@ -390,6 +390,7 @@ void intel_shared_dpll_swap_state(struct intel_atomic_state *state);
> >  void intel_shared_dpll_init(struct drm_device *dev);
> >  void intel_dpll_readout_hw_state(struct drm_i915_private *dev_priv);
> >  void intel_dpll_sanitize_state(struct drm_i915_private *dev_priv);
> > +u32 intel_get_hti_plls(struct drm_i915_private *dev_priv);
> >  
> >  void intel_dpll_dump_hw_state(struct drm_i915_private *dev_priv,
> >  			      const struct intel_dpll_hw_state *hw_state);
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index e99255e17eb7..668b3c9cf3ae 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -1037,6 +1037,9 @@ struct drm_i915_private {
> >  
> >  	struct intel_l3_parity l3_parity;
> >  
> > +	/* Mask of PLLs reserved for use by HTI and unavailable to driver. */
> > +	u32 hti_pll_mask;
> > +
> >  	/*
> >  	 * edram size in MB.
> >  	 * Cannot be determined by PCIID. You must always read a register.
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 85137d268c4a..b9faf0f978cf 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -2906,6 +2906,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
> >  #define MBUS_BBOX_CTL_S1		_MMIO(0x45040)
> >  #define MBUS_BBOX_CTL_S2		_MMIO(0x45044)
> >  
> > +#define HDPORT_STATE			_MMIO(0x45050)
> > +#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(14, 12)
> > +#define   HDPORT_PHY_USED_DP(phy)	REG_BIT(2*(phy) + 2)
> > +#define   HDPORT_PHY_USED_HDMI(phy)	REG_BIT(2*(phy) + 1)
> > +#define   HDPORT_ENABLED		REG_BIT(0)
> > +
> >  /* Make render/texture TLB fetches lower priorty than associated data
> >   *   fetches. This is not turned on by default
> >   */
> > -- 
> > 2.24.1
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index bcc6dc4e321b..cdd84a419cf7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -46,6 +46,7 @@ 
 #include "display/intel_ddi.h"
 #include "display/intel_dp.h"
 #include "display/intel_dp_mst.h"
+#include "display/intel_dpll_mgr.h"
 #include "display/intel_dsi.h"
 #include "display/intel_dvo.h"
 #include "display/intel_gmbus.h"
@@ -16817,6 +16818,13 @@  static void intel_pps_init(struct drm_i915_private *dev_priv)
 	intel_pps_unlock_regs_wa(dev_priv);
 }
 
+static bool hti_uses_phy(u32 hdport_state, enum phy phy)
+{
+	return hdport_state & HDPORT_ENABLED &&
+		(hdport_state & HDPORT_PHY_USED_DP(phy) ||
+		 hdport_state & HDPORT_PHY_USED_HDMI(phy));
+}
+
 static void intel_setup_outputs(struct drm_i915_private *dev_priv)
 {
 	struct intel_encoder *encoder;
@@ -16828,10 +16836,22 @@  static void intel_setup_outputs(struct drm_i915_private *dev_priv)
 		return;
 
 	if (IS_ROCKETLAKE(dev_priv)) {
-		intel_ddi_init(dev_priv, PORT_A);
-		intel_ddi_init(dev_priv, PORT_B);
-		intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
-		intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
+		/*
+		 * If HTI (aka HDPORT) is enabled at boot, it may have taken
+		 * over some of the PHYs and made them unavailable to the
+		 * driver.  In that case we should skip initializing the
+		 * corresponding outputs.
+		 */
+		u32 hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
+
+		if (!hti_uses_phy(hdport_state, PHY_A))
+			intel_ddi_init(dev_priv, PORT_A);
+		if (!hti_uses_phy(hdport_state, PHY_B))
+			intel_ddi_init(dev_priv, PORT_B);
+		if (!hti_uses_phy(hdport_state, PHY_C))
+			intel_ddi_init(dev_priv, PORT_D);	/* DDI TC1 */
+		if (!hti_uses_phy(hdport_state, PHY_D))
+			intel_ddi_init(dev_priv, PORT_E);	/* DDI TC2 */
 	} else if (INTEL_GEN(dev_priv) >= 12) {
 		intel_ddi_init(dev_priv, PORT_A);
 		intel_ddi_init(dev_priv, PORT_B);
@@ -18379,6 +18399,8 @@  static void intel_modeset_readout_hw_state(struct drm_device *dev)
 
 	intel_dpll_readout_hw_state(dev_priv);
 
+	dev_priv->hti_pll_mask = intel_get_hti_plls(dev_priv);
+
 	for_each_intel_encoder(dev, encoder) {
 		pipe = 0;
 
diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
index b5f4d4cef682..6f59f9ec453b 100644
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
@@ -265,6 +265,24 @@  void intel_disable_shared_dpll(const struct intel_crtc_state *crtc_state)
 	mutex_unlock(&dev_priv->dpll.lock);
 }
 
+/*
+ * HTI (aka HDPORT) may be using some of the platform's PLL's, making them
+ * unavailable for use.
+ */
+u32 intel_get_hti_plls(struct drm_i915_private *dev_priv)
+{
+	u32 hdport_state;
+
+	if (!IS_ROCKETLAKE(dev_priv))
+		return 0;
+
+	hdport_state = intel_de_read(dev_priv, HDPORT_STATE);
+	if (!(hdport_state & HDPORT_ENABLED))
+		return 0;
+
+	return REG_FIELD_GET(HDPORT_DPLL_USED_MASK, hdport_state);
+}
+
 static struct intel_shared_dpll *
 intel_find_shared_dpll(struct intel_atomic_state *state,
 		       const struct intel_crtc *crtc,
@@ -280,6 +298,9 @@  intel_find_shared_dpll(struct intel_atomic_state *state,
 
 	drm_WARN_ON(&dev_priv->drm, dpll_mask & ~(BIT(I915_NUM_PLLS) - 1));
 
+	/* Eliminate DPLLs from consideration if reserved by HTI */
+	dpll_mask &= ~dev_priv->hti_pll_mask;
+
 	for_each_set_bit(i, &dpll_mask, I915_NUM_PLLS) {
 		pll = &dev_priv->dpll.shared_dplls[i];
 
diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
index 5d9a2bc371e7..ac2238646fe7 100644
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
@@ -390,6 +390,7 @@  void intel_shared_dpll_swap_state(struct intel_atomic_state *state);
 void intel_shared_dpll_init(struct drm_device *dev);
 void intel_dpll_readout_hw_state(struct drm_i915_private *dev_priv);
 void intel_dpll_sanitize_state(struct drm_i915_private *dev_priv);
+u32 intel_get_hti_plls(struct drm_i915_private *dev_priv);
 
 void intel_dpll_dump_hw_state(struct drm_i915_private *dev_priv,
 			      const struct intel_dpll_hw_state *hw_state);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e99255e17eb7..668b3c9cf3ae 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1037,6 +1037,9 @@  struct drm_i915_private {
 
 	struct intel_l3_parity l3_parity;
 
+	/* Mask of PLLs reserved for use by HTI and unavailable to driver. */
+	u32 hti_pll_mask;
+
 	/*
 	 * edram size in MB.
 	 * Cannot be determined by PCIID. You must always read a register.
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 85137d268c4a..b9faf0f978cf 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2906,6 +2906,12 @@  static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define MBUS_BBOX_CTL_S1		_MMIO(0x45040)
 #define MBUS_BBOX_CTL_S2		_MMIO(0x45044)
 
+#define HDPORT_STATE			_MMIO(0x45050)
+#define   HDPORT_DPLL_USED_MASK		REG_GENMASK(14, 12)
+#define   HDPORT_PHY_USED_DP(phy)	REG_BIT(2*(phy) + 2)
+#define   HDPORT_PHY_USED_HDMI(phy)	REG_BIT(2*(phy) + 1)
+#define   HDPORT_ENABLED		REG_BIT(0)
+
 /* Make render/texture TLB fetches lower priorty than associated data
  *   fetches. This is not turned on by default
  */