[Intel-gfx] [PATCH 19/37] drm/i915/dg1: Wait for pcode/uncore handshake at startup

[Lucas De Marchi]

From: Matt Roper <matthew.d.roper at intel.com>

DG1 does some additional pcode/uncore handshaking at
boot time; this handshaking must complete before various other pcode
commands are effective and before general work is submitted to the GPU.
We need to poll a new pcode mailbox during startup until it reports that
this handshaking is complete.

The bspec doesn't give guidance on how long we may need to wait for this
handshaking to complete.  For now, let's just set a really long timeout;
if we still don't get a completion status by the end of that timeout,
we'll just continue on and hope for the best.

Bspec: 52065
Cc: Clinton Taylor <Clinton.A.Taylor at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c       |  3 +++
 drivers/gpu/drm/i915/i915_reg.h       |  3 +++
 drivers/gpu/drm/i915/intel_sideband.c | 15 +++++++++++++++
 drivers/gpu/drm/i915/intel_sideband.h |  2 ++
 4 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 34ee12f3f02d..58b9c6b778aa 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -85,6 +85,7 @@
 #include "intel_gvt.h"
 #include "intel_memory_region.h"
 #include "intel_pm.h"
+#include "intel_sideband.h"
 #include "vlv_suspend.h"
 
 static struct drm_driver driver;
@@ -741,6 +742,8 @@ static int i915_driver_hw_probe(struct drm_i915_private *dev_priv)
 	 */
 	intel_dram_detect(dev_priv);
 
+	intel_pcode_init(dev_priv);
+
 	intel_bw_init_hw(dev_priv);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c1fde43867dc..53b0ad1805f6 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9128,6 +9128,9 @@ enum {
 #define     GEN9_SAGV_DISABLE			0x0
 #define     GEN9_SAGV_IS_DISABLED		0x1
 #define     GEN9_SAGV_ENABLE			0x3
+#define   DG1_PCODE_STATUS			0x7E
+#define     DG1_CHECK_UNCORE_INIT_STATUS	0x0
+#define     DG1_UNCORE_INIT_COMPLETE		0x1
 #define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US	0x23
 #define GEN6_PCODE_DATA				_MMIO(0x138128)
 #define   GEN6_PCODE_FREQ_IA_RATIO_SHIFT	8
diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index 916ccd1c0e96..8b093525240d 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -543,3 +543,18 @@ int skl_pcode_request(struct drm_i915_private *i915, u32 mbox, u32 request,
 	return ret ? ret : status;
 #undef COND
 }
+
+void intel_pcode_init(struct drm_i915_private *i915)
+{
+	int ret;
+
+	if (!IS_DGFX(i915))
+		return;
+
+	ret = skl_pcode_request(i915, DG1_PCODE_STATUS,
+				DG1_CHECK_UNCORE_INIT_STATUS,
+				DG1_UNCORE_INIT_COMPLETE,
+				DG1_UNCORE_INIT_COMPLETE, 50);
+	if (ret)
+		drm_err(&i915->drm, "Pcode did not report uncore initialization completion!\n");
+}
diff --git a/drivers/gpu/drm/i915/intel_sideband.h b/drivers/gpu/drm/i915/intel_sideband.h
index 7fb95745a444..094c7b19c5d4 100644
--- a/drivers/gpu/drm/i915/intel_sideband.h
+++ b/drivers/gpu/drm/i915/intel_sideband.h
@@ -138,4 +138,6 @@ int sandybridge_pcode_write_timeout(struct drm_i915_private *i915, u32 mbox,
 int skl_pcode_request(struct drm_i915_private *i915, u32 mbox, u32 request,
 		      u32 reply_mask, u32 reply, int timeout_base_ms);
 
+void intel_pcode_init(struct drm_i915_private *i915);
+
 #endif /* _INTEL_SIDEBAND_H */
-- 
2.26.2