From ad779e820fadb7c42ea1c609e177b07f98c22a21 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Sun, 1 Jan 2017 13:56:11 +0100
Subject: [PATCH v8] drm/i915: Acquire P-Unit access when modifying P-Unit
 settings

Make sure the P-Unit or the PMIC i2c bus is not in use when we send a
request to the P-Unit by calling iosf_mbi_punit_acquire() / _release()
around P-Unit write accesses.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
---
Changes in v2:
-Spelling: P-Unit, PMIC
-Adjust for iosf_mbi_punit_lock/_unlock to _acquire/_release rename
Changes in v3:
-Make sure IOSF_MBI is builtin if the i915 driver is builtin
-Add comments explaining why calling iosf_mbi_punit_acquire is necessary
---
 drivers/gpu/drm/i915/intel_display.c    |  8 ++++++++
 drivers/gpu/drm/i915/intel_pm.c         | 13 +++++++++++++
 drivers/gpu/drm/i915/intel_runtime_pm.c | 11 +++++++++++
 3 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 88689a0..cc54378 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -47,6 +47,7 @@
 #include <drm/drm_rect.h>
 #include <linux/dma_remapping.h>
 #include <linux/reservation.h>
+#include <asm/iosf_mbi.h>
 
 static bool is_mmio_work(struct intel_flip_work *work)
 {
@@ -6422,6 +6423,9 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
 		cmd = 0;
 
 	mutex_lock(&dev_priv->rps.hw_lock);
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
+
 	val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
 	val &= ~DSPFREQGUAR_MASK;
 	val |= (cmd << DSPFREQGUAR_SHIFT);
@@ -6431,6 +6435,7 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
 		     50)) {
 		DRM_ERROR("timed out waiting for CDclk change\n");
 	}
+	iosf_mbi_punit_release();
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
 	mutex_lock(&dev_priv->sb_lock);
@@ -6498,6 +6503,8 @@ static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
 	cmd = DIV_ROUND_CLOSEST(dev_priv->hpll_freq << 1, cdclk) - 1;
 
 	mutex_lock(&dev_priv->rps.hw_lock);
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
 	val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
 	val &= ~DSPFREQGUAR_MASK_CHV;
 	val |= (cmd << DSPFREQGUAR_SHIFT_CHV);
@@ -6507,6 +6514,7 @@ static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
 		     50)) {
 		DRM_ERROR("timed out waiting for CDclk change\n");
 	}
+	iosf_mbi_punit_release();
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
 	intel_update_cdclk(dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index ec16f3d6..d2498b8 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -32,6 +32,7 @@
 #include "../../../platform/x86/intel_ips.h"
 #include <linux/module.h>
 #include <drm/drm_atomic_helper.h>
+#include <asm/iosf_mbi.h>
 
 /**
  * DOC: RC6
@@ -289,6 +290,8 @@ static void chv_set_memory_dvfs(struct drm_i915_private *dev_priv, bool enable)
 	u32 val;
 
 	mutex_lock(&dev_priv->rps.hw_lock);
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
 
 	val = vlv_punit_read(dev_priv, PUNIT_REG_DDR_SETUP2);
 	if (enable)
@@ -303,6 +306,7 @@ static void chv_set_memory_dvfs(struct drm_i915_private *dev_priv, bool enable)
 		      FORCE_DDR_FREQ_REQ_ACK) == 0, 3))
 		DRM_ERROR("timed out waiting for Punit DDR DVFS request\n");
 
+	iosf_mbi_punit_release();
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }
 
@@ -311,6 +315,8 @@ static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
 	u32 val;
 
 	mutex_lock(&dev_priv->rps.hw_lock);
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
 
 	val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
 	if (enable)
@@ -319,6 +325,7 @@ static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
 		val &= ~DSP_MAXFIFO_PM5_ENABLE;
 	vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
 
+	iosf_mbi_punit_release();
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }
 
@@ -4565,6 +4572,8 @@ void vlv_wm_get_hw_state(struct drm_device *dev)
 
 	if (IS_CHERRYVIEW(dev_priv)) {
 		mutex_lock(&dev_priv->rps.hw_lock);
+		/* Claim the pmic on systems where the punit shares its bus */
+		iosf_mbi_punit_acquire();
 
 		val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
 		if (val & DSP_MAXFIFO_PM5_ENABLE)
@@ -4594,6 +4603,7 @@ void vlv_wm_get_hw_state(struct drm_device *dev)
 				wm->level = VLV_WM_LEVEL_DDR_DVFS;
 		}
 
+		iosf_mbi_punit_release();
 		mutex_unlock(&dev_priv->rps.hw_lock);
 	}
 
@@ -5000,7 +5010,10 @@ static int valleyview_set_rps(struct drm_i915_private *dev_priv, u8 val)
 	I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));
 
 	if (val != dev_priv->rps.cur_freq) {
+		/* Claim the pmic on systems where the punit shares its bus */
+		iosf_mbi_punit_acquire();
 		err = vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
+		iosf_mbi_punit_release();
 		if (err)
 			return err;
 
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 66aa1bb..4704b40 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -28,6 +28,7 @@
 
 #include <linux/pm_runtime.h>
 #include <linux/vgaarb.h>
+#include <asm/iosf_mbi.h>
 
 #include "i915_drv.h"
 #include "intel_drv.h"
@@ -1027,6 +1028,9 @@ static void vlv_set_power_well(struct drm_i915_private *dev_priv,
 	if (COND)
 		goto out;
 
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
+
 	ctrl = vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL);
 	ctrl &= ~mask;
 	ctrl |= state;
@@ -1037,6 +1041,8 @@ static void vlv_set_power_well(struct drm_i915_private *dev_priv,
 			  state,
 			  vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL));
 
+	iosf_mbi_punit_release();
+
 #undef COND
 
 out:
@@ -1643,6 +1649,9 @@ static void chv_set_pipe_power_well(struct drm_i915_private *dev_priv,
 	if (COND)
 		goto out;
 
+	/* Claim the pmic bus on systems where the punit shares the pmic bus */
+	iosf_mbi_punit_acquire();
+
 	ctrl = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
 	ctrl &= ~DP_SSC_MASK(pipe);
 	ctrl |= enable ? DP_SSC_PWR_ON(pipe) : DP_SSC_PWR_GATE(pipe);
@@ -1653,6 +1662,8 @@ static void chv_set_pipe_power_well(struct drm_i915_private *dev_priv,
 			  state,
 			  vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ));
 
+	iosf_mbi_punit_release();
+
 #undef COND
 
 out:
-- 
2.9.3

