From 615c16a9d8649b9894592d11bc393e684b11e2ea Mon Sep 17 00:00:00 2001
From: fred gao <fred.gao@intel.com>
Date: Thu, 25 May 2017 15:33:52 +0800
Subject: [PATCH] drm/i915/gvt: Refine virtual reset function
Git-commit: 615c16a9d8649b9894592d11bc393e684b11e2ea
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900

during the emulation of virtual reset:
1. only reset the engine related mmio ending with MMIO
   offset Master_IRQ, not include display stuff.

2. fences are not required to set default
   value as well to prevent screen flicking.

this will fix the issue of Guest screen hang while running
Force tdr in Linux guest.

V2: 
- only reset the engine related mmio. (Zhenyu & Zhiyuan)
V3: 
- IMR/Ring mode registers are not save/restored. (Changbin)
V4: 
- redefine the MMIO reset offset for easy understanding. (Zhenyu)
- pvinfo can be reset. (Zhenyu)
V5: 
- add more comments for mmio reset. (Zhenyu)

Cc: Changbin Du <changbin.du@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Lv zhiyuan <zhiyuan.lv@intel.com>
Cc: Zhang Yulei <yulei.zhang@intel.com>
Signed-off-by: fred gao <fred.gao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/mmio.c |   32 ++++++++++++++++++++++----------
 drivers/gpu/drm/i915/gvt/mmio.h |    2 +-
 drivers/gpu/drm/i915/gvt/vgpu.c |    9 +++++++--
 3 files changed, 30 insertions(+), 13 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/mmio.c
+++ b/drivers/gpu/drm/i915/gvt/mmio.c
@@ -289,20 +289,32 @@ err:
  * @vgpu: a vGPU
  *
  */
-void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu)
+void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu, bool dmlr)
 {
 	struct intel_gvt *gvt = vgpu->gvt;
 	const struct intel_gvt_device_info *info = &gvt->device_info;
+	void  *mmio = gvt->firmware.mmio;
 
-	memcpy(vgpu->mmio.vreg, gvt->firmware.mmio, info->mmio_size);
-	memcpy(vgpu->mmio.sreg, gvt->firmware.mmio, info->mmio_size);
+	if (dmlr) {
+		memcpy(vgpu->mmio.vreg, mmio, info->mmio_size);
+		memcpy(vgpu->mmio.sreg, mmio, info->mmio_size);
+
+		vgpu_vreg(vgpu, GEN6_GT_THREAD_STATUS_REG) = 0;
+
+		/* set the bit 0:2(Core C-State ) to C0 */
+		vgpu_vreg(vgpu, GEN6_GT_CORE_STATUS) = 0;
+
+		vgpu->mmio.disable_warn_untrack = false;
+	} else {
+#define GVT_GEN8_MMIO_RESET_OFFSET		(0x44200)
+		/* only reset the engine related, so starting with 0x44200
+		 * interrupt include DE,display mmio related will not be
+		 * touched
+		 */
+		memcpy(vgpu->mmio.vreg, mmio, GVT_GEN8_MMIO_RESET_OFFSET);
+		memcpy(vgpu->mmio.sreg, mmio, GVT_GEN8_MMIO_RESET_OFFSET);
+	}
 
-	vgpu_vreg(vgpu, GEN6_GT_THREAD_STATUS_REG) = 0;
-
-	/* set the bit 0:2(Core C-State ) to C0 */
-	vgpu_vreg(vgpu, GEN6_GT_CORE_STATUS) = 0;
-
-	vgpu->mmio.disable_warn_untrack = false;
 }
 
 /**
@@ -322,7 +334,7 @@ int intel_vgpu_init_mmio(struct intel_vg
 
 	vgpu->mmio.sreg = vgpu->mmio.vreg + info->mmio_size;
 
-	intel_vgpu_reset_mmio(vgpu);
+	intel_vgpu_reset_mmio(vgpu, true);
 
 	return 0;
 }
--- a/drivers/gpu/drm/i915/gvt/mmio.h
+++ b/drivers/gpu/drm/i915/gvt/mmio.h
@@ -78,7 +78,7 @@ void intel_gvt_clean_mmio_info(struct in
 })
 
 int intel_vgpu_init_mmio(struct intel_vgpu *vgpu);
-void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu);
+void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu, bool dmlr);
 void intel_vgpu_clean_mmio(struct intel_vgpu *vgpu);
 
 int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa);
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -501,9 +501,14 @@ void intel_gvt_reset_vgpu_locked(struct
 
 	/* full GPU reset or device model level reset */
 	if (engine_mask == ALL_ENGINES || dmlr) {
+
 		intel_vgpu_reset_gtt(vgpu, dmlr);
-		intel_vgpu_reset_resource(vgpu);
-		intel_vgpu_reset_mmio(vgpu);
+
+		/*fence will not be reset during virtual reset */
+		if (dmlr)
+			intel_vgpu_reset_resource(vgpu);
+
+		intel_vgpu_reset_mmio(vgpu, dmlr);
 		populate_pvinfo_page(vgpu);
 		intel_vgpu_reset_display(vgpu);