drm/i915/gvt: vGPU display virtualization

This patch introduces the GVT-g display virtualization.

It consists a collection of display MMIO handlers, like power well register
handler, pipe register handler, plane register handler, which will emulate
all display MMIOs behavior to support virtual mode setting sequence for
guest.

Signed-off-by: Bing Niu <bing.niu@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

12 files changed, 2277 insertions, 115 deletions

diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile
index 1a783a19bc4d..f87cd7fe9574 100644
--- a/drivers/gpu/drm/i915/gvt/Makefile
+++ b/drivers/gpu/drm/i915/gvt/Makefile
@@ -1,6 +1,6 @@
 GVT_DIR := gvt
 GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
-	interrupt.o gtt.o cfg_space.o opregion.o mmio.o
+	interrupt.o gtt.o cfg_space.o opregion.o mmio.o display.o edid.o
 
 ccflags-y                      += -I$(src) -I$(src)/$(GVT_DIR) -Wall
 i915-y			       += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))
diff --git a/drivers/gpu/drm/i915/gvt/debug.h b/drivers/gpu/drm/i915/gvt/debug.h
index 47fabb065ac5..5c21c585ac00 100644
--- a/drivers/gpu/drm/i915/gvt/debug.h
+++ b/drivers/gpu/drm/i915/gvt/debug.h
@@ -39,4 +39,7 @@
 #define gvt_dbg_mmio(fmt, args...) \
 	DRM_DEBUG_DRIVER("gvt: mmio: "fmt, ##args)
 
+#define gvt_dbg_dpy(fmt, args...) \
+	DRM_DEBUG_DRIVER("gvt: dpy: "fmt, ##args)
+
 #endif
diff --git a/drivers/gpu/drm/i915/gvt/display.c b/drivers/gpu/drm/i915/gvt/display.c
new file mode 100644
index 000000000000..534000b91681
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/display.c
@@ -0,0 +1,329 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Ke Yu
+ *    Zhiyuan Lv <zhiyuan.lv@intel.com>
+ *
+ * Contributors:
+ *    Terrence Xu <terrence.xu@intel.com>
+ *    Changbin Du <changbin.du@intel.com>
+ *    Bing Niu <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+static int get_edp_pipe(struct intel_vgpu *vgpu)
+{
+	u32 data = vgpu_vreg(vgpu, _TRANS_DDI_FUNC_CTL_EDP);
+	int pipe = -1;
+
+	switch (data & TRANS_DDI_EDP_INPUT_MASK) {
+	case TRANS_DDI_EDP_INPUT_A_ON:
+	case TRANS_DDI_EDP_INPUT_A_ONOFF:
+		pipe = PIPE_A;
+		break;
+	case TRANS_DDI_EDP_INPUT_B_ONOFF:
+		pipe = PIPE_B;
+		break;
+	case TRANS_DDI_EDP_INPUT_C_ONOFF:
+		pipe = PIPE_C;
+		break;
+	}
+	return pipe;
+}
+
+static int edp_pipe_is_enabled(struct intel_vgpu *vgpu)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+
+	if (!(vgpu_vreg(vgpu, PIPECONF(_PIPE_EDP)) & PIPECONF_ENABLE))
+		return 0;
+
+	if (!(vgpu_vreg(vgpu, _TRANS_DDI_FUNC_CTL_EDP) & TRANS_DDI_FUNC_ENABLE))
+		return 0;
+	return 1;
+}
+
+static int pipe_is_enabled(struct intel_vgpu *vgpu, int pipe)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+
+	if (WARN_ON(pipe < PIPE_A || pipe >= I915_MAX_PIPES))
+		return -EINVAL;
+
+	if (vgpu_vreg(vgpu, PIPECONF(pipe)) & PIPECONF_ENABLE)
+		return 1;
+
+	if (edp_pipe_is_enabled(vgpu) &&
+			get_edp_pipe(vgpu) == pipe)
+		return 1;
+	return 0;
+}
+
+/* EDID with 1024x768 as its resolution */
+static unsigned char virtual_dp_monitor_edid[] = {
+	/*Header*/
+	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
+	/* Vendor & Product Identification */
+	0x22, 0xf0, 0x54, 0x29, 0x00, 0x00, 0x00, 0x00, 0x04, 0x17,
+	/* Version & Revision */
+	0x01, 0x04,
+	/* Basic Display Parameters & Features */
+	0xa5, 0x34, 0x20, 0x78, 0x23,
+	/* Color Characteristics */
+	0xfc, 0x81, 0xa4, 0x55, 0x4d, 0x9d, 0x25, 0x12, 0x50, 0x54,
+	/* Established Timings: maximum resolution is 1024x768 */
+	0x21, 0x08, 0x00,
+	/* Standard Timings. All invalid */
+	0x00, 0xc0, 0x00, 0xc0, 0x00, 0x40, 0x00, 0x80, 0x00, 0x00,
+	0x00, 0x40, 0x00, 0x00, 0x00, 0x01,
+	/* 18 Byte Data Blocks 1: invalid */
+	0x00, 0x00, 0x80, 0xa0, 0x70, 0xb0,
+	0x23, 0x40, 0x30, 0x20, 0x36, 0x00, 0x06, 0x44, 0x21, 0x00, 0x00, 0x1a,
+	/* 18 Byte Data Blocks 2: invalid */
+	0x00, 0x00, 0x00, 0xfd, 0x00, 0x18, 0x3c, 0x18, 0x50, 0x11, 0x00, 0x0a,
+	0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+	/* 18 Byte Data Blocks 3: invalid */
+	0x00, 0x00, 0x00, 0xfc, 0x00, 0x48,
+	0x50, 0x20, 0x5a, 0x52, 0x32, 0x34, 0x34, 0x30, 0x77, 0x0a, 0x20, 0x20,
+	/* 18 Byte Data Blocks 4: invalid */
+	0x00, 0x00, 0x00, 0xff, 0x00, 0x43, 0x4e, 0x34, 0x33, 0x30, 0x34, 0x30,
+	0x44, 0x58, 0x51, 0x0a, 0x20, 0x20,
+	/* Extension Block Count */
+	0x00,
+	/* Checksum */
+	0xef,
+};
+
+#define DPCD_HEADER_SIZE        0xb
+
+u8 dpcd_fix_data[DPCD_HEADER_SIZE] = {
+	0x11, 0x0a, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static void emulate_monitor_status_change(struct intel_vgpu *vgpu)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+	vgpu_vreg(vgpu, SDEISR) &= ~(SDE_PORTB_HOTPLUG_CPT |
+			SDE_PORTC_HOTPLUG_CPT |
+			SDE_PORTD_HOTPLUG_CPT);
+
+	if (IS_SKYLAKE(dev_priv))
+		vgpu_vreg(vgpu, SDEISR) &= ~(SDE_PORTA_HOTPLUG_SPT |
+				SDE_PORTE_HOTPLUG_SPT);
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, PORT_B))
+		vgpu_vreg(vgpu, SDEISR) |= SDE_PORTB_HOTPLUG_CPT;
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, PORT_C))
+		vgpu_vreg(vgpu, SDEISR) |= SDE_PORTC_HOTPLUG_CPT;
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, PORT_D))
+		vgpu_vreg(vgpu, SDEISR) |= SDE_PORTD_HOTPLUG_CPT;
+
+	if (IS_SKYLAKE(dev_priv) &&
+			intel_vgpu_has_monitor_on_port(vgpu, PORT_E)) {
+		vgpu_vreg(vgpu, SDEISR) |= SDE_PORTE_HOTPLUG_SPT;
+	}
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, PORT_A)) {
+		if (IS_BROADWELL(dev_priv))
+			vgpu_vreg(vgpu, GEN8_DE_PORT_ISR) |=
+				GEN8_PORT_DP_A_HOTPLUG;
+		else
+			vgpu_vreg(vgpu, SDEISR) |= SDE_PORTA_HOTPLUG_SPT;
+	}
+}
+
+static void clean_virtual_dp_monitor(struct intel_vgpu *vgpu, int port_num)
+{
+	struct intel_vgpu_port *port = intel_vgpu_port(vgpu, port_num);
+
+	kfree(port->edid);
+	port->edid = NULL;
+
+	kfree(port->dpcd);
+	port->dpcd = NULL;
+}
+
+static int setup_virtual_dp_monitor(struct intel_vgpu *vgpu, int port_num,
+		int type)
+{
+	struct intel_vgpu_port *port = intel_vgpu_port(vgpu, port_num);
+
+	port->edid = kzalloc(sizeof(*(port->edid)), GFP_KERNEL);
+	if (!port->edid)
+		return -ENOMEM;
+
+	port->dpcd = kzalloc(sizeof(*(port->dpcd)), GFP_KERNEL);
+	if (!port->dpcd) {
+		kfree(port->edid);
+		return -ENOMEM;
+	}
+
+	memcpy(port->edid->edid_block, virtual_dp_monitor_edid,
+			EDID_SIZE);
+	port->edid->data_valid = true;
+
+	memcpy(port->dpcd->data, dpcd_fix_data, DPCD_HEADER_SIZE);
+	port->dpcd->data_valid = true;
+	port->dpcd->data[DPCD_SINK_COUNT] = 0x1;
+	port->type = type;
+
+	emulate_monitor_status_change(vgpu);
+	return 0;
+}
+
+/**
+ * intel_gvt_check_vblank_emulation - check if vblank emulation timer should
+ * be turned on/off when a virtual pipe is enabled/disabled.
+ * @gvt: a GVT device
+ *
+ * This function is used to turn on/off vblank timer according to currently
+ * enabled/disabled virtual pipes.
+ *
+ */
+void intel_gvt_check_vblank_emulation(struct intel_gvt *gvt)
+{
+	struct intel_gvt_irq *irq = &gvt->irq;
+	struct intel_vgpu *vgpu;
+	bool have_enabled_pipe = false;
+	int pipe, id;
+
+	if (WARN_ON(!mutex_is_locked(&gvt->lock)))
+		return;
+
+	hrtimer_cancel(&irq->vblank_timer.timer);
+
+	for_each_active_vgpu(gvt, vgpu, id) {
+		for (pipe = 0; pipe < I915_MAX_PIPES; pipe++) {
+			have_enabled_pipe =
+				pipe_is_enabled(vgpu, pipe);
+			if (have_enabled_pipe)
+				break;
+		}
+	}
+
+	if (have_enabled_pipe)
+		hrtimer_start(&irq->vblank_timer.timer,
+			ktime_add_ns(ktime_get(), irq->vblank_timer.period),
+			HRTIMER_MODE_ABS);
+}
+
+static void emulate_vblank_on_pipe(struct intel_vgpu *vgpu, int pipe)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+	struct intel_vgpu_irq *irq = &vgpu->irq;
+	int vblank_event[] = {
+		[PIPE_A] = PIPE_A_VBLANK,
+		[PIPE_B] = PIPE_B_VBLANK,
+		[PIPE_C] = PIPE_C_VBLANK,
+	};
+	int event;
+
+	if (pipe < PIPE_A || pipe > PIPE_C)
+		return;
+
+	for_each_set_bit(event, irq->flip_done_event[pipe],
+			INTEL_GVT_EVENT_MAX) {
+		clear_bit(event, irq->flip_done_event[pipe]);
+		if (!pipe_is_enabled(vgpu, pipe))
+			continue;
+
+		vgpu_vreg(vgpu, PIPE_FLIPCOUNT_G4X(pipe))++;
+		intel_vgpu_trigger_virtual_event(vgpu, event);
+	}
+
+	if (pipe_is_enabled(vgpu, pipe)) {
+		vgpu_vreg(vgpu, PIPE_FRMCOUNT_G4X(pipe))++;
+		intel_vgpu_trigger_virtual_event(vgpu, vblank_event[pipe]);
+	}
+}
+
+static void emulate_vblank(struct intel_vgpu *vgpu)
+{
+	int pipe;
+
+	for_each_pipe(vgpu->gvt->dev_priv, pipe)
+		emulate_vblank_on_pipe(vgpu, pipe);
+}
+
+/**
+ * intel_gvt_emulate_vblank - trigger vblank events for vGPUs on GVT device
+ * @gvt: a GVT device
+ *
+ * This function is used to trigger vblank interrupts for vGPUs on GVT device
+ *
+ */
+void intel_gvt_emulate_vblank(struct intel_gvt *gvt)
+{
+	struct intel_vgpu *vgpu;
+	int id;
+
+	if (WARN_ON(!mutex_is_locked(&gvt->lock)))
+		return;
+
+	for_each_active_vgpu(gvt, vgpu, id)
+		emulate_vblank(vgpu);
+}
+
+/**
+ * intel_vgpu_clean_display - clean vGPU virtual display emulation
+ * @vgpu: a vGPU
+ *
+ * This function is used to clean vGPU virtual display emulation stuffs
+ *
+ */
+void intel_vgpu_clean_display(struct intel_vgpu *vgpu)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+
+	if (IS_SKYLAKE(dev_priv))
+		clean_virtual_dp_monitor(vgpu, PORT_D);
+	else
+		clean_virtual_dp_monitor(vgpu, PORT_B);
+}
+
+/**
+ * intel_vgpu_init_display- initialize vGPU virtual display emulation
+ * @vgpu: a vGPU
+ *
+ * This function is used to initialize vGPU virtual display emulation stuffs
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_vgpu_init_display(struct intel_vgpu *vgpu)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+
+	intel_vgpu_init_i2c_edid(vgpu);
+
+	if (IS_SKYLAKE(dev_priv))
+		return setup_virtual_dp_monitor(vgpu, PORT_D, GVT_DP_D);
+	else
+		return setup_virtual_dp_monitor(vgpu, PORT_B, GVT_DP_B);
+}
diff --git a/drivers/gpu/drm/i915/gvt/display.h b/drivers/gpu/drm/i915/gvt/display.h
new file mode 100644
index 000000000000..7a60cb848268
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/display.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Ke Yu
+ *    Zhiyuan Lv <zhiyuan.lv@intel.com>
+ *
+ * Contributors:
+ *    Terrence Xu <terrence.xu@intel.com>
+ *    Changbin Du <changbin.du@intel.com>
+ *    Bing Niu <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#ifndef _GVT_DISPLAY_H_
+#define _GVT_DISPLAY_H_
+
+#define SBI_REG_MAX	20
+#define DPCD_SIZE	0x700
+
+#define intel_vgpu_port(vgpu, port) \
+	(&(vgpu->display.ports[port]))
+
+#define intel_vgpu_has_monitor_on_port(vgpu, port) \
+	(intel_vgpu_port(vgpu, port)->edid && \
+		intel_vgpu_port(vgpu, port)->edid->data_valid)
+
+#define intel_vgpu_port_is_dp(vgpu, port) \
+	((intel_vgpu_port(vgpu, port)->type == GVT_DP_A) || \
+	(intel_vgpu_port(vgpu, port)->type == GVT_DP_B) || \
+	(intel_vgpu_port(vgpu, port)->type == GVT_DP_C) || \
+	(intel_vgpu_port(vgpu, port)->type == GVT_DP_D))
+
+#define INTEL_GVT_MAX_UEVENT_VARS	3
+
+/* DPCD start */
+#define DPCD_SIZE	0x700
+
+/* DPCD */
+#define DP_SET_POWER            0x600
+#define DP_SET_POWER_D0         0x1
+#define AUX_NATIVE_WRITE        0x8
+#define AUX_NATIVE_READ         0x9
+
+#define AUX_NATIVE_REPLY_MASK   (0x3 << 4)
+#define AUX_NATIVE_REPLY_ACK    (0x0 << 4)
+#define AUX_NATIVE_REPLY_NAK    (0x1 << 4)
+#define AUX_NATIVE_REPLY_DEFER  (0x2 << 4)
+
+#define AUX_BURST_SIZE          16
+
+/* DPCD addresses */
+#define DPCD_REV			0x000
+#define DPCD_MAX_LINK_RATE		0x001
+#define DPCD_MAX_LANE_COUNT		0x002
+
+#define DPCD_TRAINING_PATTERN_SET	0x102
+#define	DPCD_SINK_COUNT			0x200
+#define DPCD_LANE0_1_STATUS		0x202
+#define DPCD_LANE2_3_STATUS		0x203
+#define DPCD_LANE_ALIGN_STATUS_UPDATED	0x204
+#define DPCD_SINK_STATUS		0x205
+
+/* link training */
+#define DPCD_TRAINING_PATTERN_SET_MASK	0x03
+#define DPCD_LINK_TRAINING_DISABLED	0x00
+#define DPCD_TRAINING_PATTERN_1		0x01
+#define DPCD_TRAINING_PATTERN_2		0x02
+
+#define DPCD_CP_READY_MASK		(1 << 6)
+
+/* lane status */
+#define DPCD_LANES_CR_DONE		0x11
+#define DPCD_LANES_EQ_DONE		0x22
+#define DPCD_SYMBOL_LOCKED		0x44
+
+#define DPCD_INTERLANE_ALIGN_DONE	0x01
+
+#define DPCD_SINK_IN_SYNC		0x03
+/* DPCD end */
+
+#define SBI_RESPONSE_MASK               0x3
+#define SBI_RESPONSE_SHIFT              0x1
+#define SBI_STAT_MASK                   0x1
+#define SBI_STAT_SHIFT                  0x0
+#define SBI_OPCODE_SHIFT                8
+#define SBI_OPCODE_MASK			(0xff << SBI_OPCODE_SHIFT)
+#define SBI_CMD_IORD                    2
+#define SBI_CMD_IOWR                    3
+#define SBI_CMD_CRRD                    6
+#define SBI_CMD_CRWR                    7
+#define SBI_ADDR_OFFSET_SHIFT           16
+#define SBI_ADDR_OFFSET_MASK            (0xffff << SBI_ADDR_OFFSET_SHIFT)
+
+struct intel_vgpu_sbi_register {
+	unsigned int offset;
+	u32 value;
+};
+
+struct intel_vgpu_sbi {
+	int number;
+	struct intel_vgpu_sbi_register registers[SBI_REG_MAX];
+};
+
+enum intel_gvt_plane_type {
+	PRIMARY_PLANE = 0,
+	CURSOR_PLANE,
+	SPRITE_PLANE,
+	MAX_PLANE
+};
+
+struct intel_vgpu_dpcd_data {
+	bool data_valid;
+	u8 data[DPCD_SIZE];
+};
+
+enum intel_vgpu_port_type {
+	GVT_CRT = 0,
+	GVT_DP_A,
+	GVT_DP_B,
+	GVT_DP_C,
+	GVT_DP_D,
+	GVT_HDMI_B,
+	GVT_HDMI_C,
+	GVT_HDMI_D,
+	GVT_PORT_MAX
+};
+
+struct intel_vgpu_port {
+	/* per display EDID information */
+	struct intel_vgpu_edid_data *edid;
+	/* per display DPCD information */
+	struct intel_vgpu_dpcd_data *dpcd;
+	int type;
+};
+
+void intel_gvt_emulate_vblank(struct intel_gvt *gvt);
+void intel_gvt_check_vblank_emulation(struct intel_gvt *gvt);
+
+int intel_vgpu_init_display(struct intel_vgpu *vgpu);
+void intel_vgpu_clean_display(struct intel_vgpu *vgpu);
+
+#endif
diff --git a/drivers/gpu/drm/i915/gvt/edid.c b/drivers/gpu/drm/i915/gvt/edid.c
new file mode 100644
index 000000000000..a07e4276126c
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/edid.c
@@ -0,0 +1,531 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Ke Yu
+ *    Zhiyuan Lv <zhiyuan.lv@intel.com>
+ *
+ * Contributors:
+ *    Terrence Xu <terrence.xu@intel.com>
+ *    Changbin Du <changbin.du@intel.com>
+ *    Bing Niu <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+#define GMBUS1_TOTAL_BYTES_SHIFT 16
+#define GMBUS1_TOTAL_BYTES_MASK 0x1ff
+#define gmbus1_total_byte_count(v) (((v) >> \
+	GMBUS1_TOTAL_BYTES_SHIFT) & GMBUS1_TOTAL_BYTES_MASK)
+#define gmbus1_slave_addr(v) (((v) & 0xff) >> 1)
+#define gmbus1_slave_index(v) (((v) >> 8) & 0xff)
+#define gmbus1_bus_cycle(v) (((v) >> 25) & 0x7)
+
+/* GMBUS0 bits definitions */
+#define _GMBUS_PIN_SEL_MASK     (0x7)
+
+static unsigned char edid_get_byte(struct intel_vgpu *vgpu)
+{
+	struct intel_vgpu_i2c_edid *edid = &vgpu->display.i2c_edid;
+	unsigned char chr = 0;
+
+	if (edid->state == I2C_NOT_SPECIFIED || !edid->slave_selected) {
+		gvt_err("Driver tries to read EDID without proper sequence!\n");
+		return 0;
+	}
+	if (edid->current_edid_read >= EDID_SIZE) {
+		gvt_err("edid_get_byte() exceeds the size of EDID!\n");
+		return 0;
+	}
+
+	if (!edid->edid_available) {
+		gvt_err("Reading EDID but EDID is not available!\n");
+		return 0;
+	}
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, edid->port)) {
+		struct intel_vgpu_edid_data *edid_data =
+			intel_vgpu_port(vgpu, edid->port)->edid;
+
+		chr = edid_data->edid_block[edid->current_edid_read];
+		edid->current_edid_read++;
+	} else {
+		gvt_err("No EDID available during the reading?\n");
+	}
+	return chr;
+}
+
+static inline int get_port_from_gmbus0(u32 gmbus0)
+{
+	int port_select = gmbus0 & _GMBUS_PIN_SEL_MASK;
+	int port = -EINVAL;
+
+	if (port_select == 2)
+		port = PORT_E;
+	else if (port_select == 4)
+		port = PORT_C;
+	else if (port_select == 5)
+		port = PORT_B;
+	else if (port_select == 6)
+		port = PORT_D;
+	return port;
+}
+
+static void reset_gmbus_controller(struct intel_vgpu *vgpu)
+{
+	vgpu_vreg(vgpu, PCH_GMBUS2) = GMBUS_HW_RDY;
+	if (!vgpu->display.i2c_edid.edid_available)
+		vgpu_vreg(vgpu, PCH_GMBUS2) |= GMBUS_SATOER;
+	vgpu->display.i2c_edid.gmbus.phase = GMBUS_IDLE_PHASE;
+}
+
+/* GMBUS0 */
+static int gmbus0_mmio_write(struct intel_vgpu *vgpu,
+			unsigned int offset, void *p_data, unsigned int bytes)
+{
+	int port, pin_select;
+
+	memcpy(&vgpu_vreg(vgpu, offset), p_data, bytes);
+
+	pin_select = vgpu_vreg(vgpu, offset) & _GMBUS_PIN_SEL_MASK;
+
+	intel_vgpu_init_i2c_edid(vgpu);
+
+	if (pin_select == 0)
+		return 0;
+
+	port = get_port_from_gmbus0(pin_select);
+	if (WARN_ON(port < 0))
+		return 0;
+
+	vgpu->display.i2c_edid.state = I2C_GMBUS;
+	vgpu->display.i2c_edid.gmbus.phase = GMBUS_IDLE_PHASE;
+
+	vgpu_vreg(vgpu, PCH_GMBUS2) &= ~GMBUS_ACTIVE;
+	vgpu_vreg(vgpu, PCH_GMBUS2) |= GMBUS_HW_RDY | GMBUS_HW_WAIT_PHASE;
+
+	if (intel_vgpu_has_monitor_on_port(vgpu, port) &&
+			!intel_vgpu_port_is_dp(vgpu, port)) {
+		vgpu->display.i2c_edid.port = port;
+		vgpu->display.i2c_edid.edid_available = true;
+		vgpu_vreg(vgpu, PCH_GMBUS2) &= ~GMBUS_SATOER;
+	} else
+		vgpu_vreg(vgpu, PCH_GMBUS2) |= GMBUS_SATOER;
+	return 0;
+}
+
+static int gmbus1_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
+		void *p_data, unsigned int bytes)
+{
+	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
+	u32 slave_addr;
+	u32 wvalue = *(u32 *)p_data;
+
+	if (vgpu_vreg(vgpu, offset) & GMBUS_SW_CLR_INT) {
+		if (!(wvalue & GMBUS_SW_CLR_INT)) {
+			vgpu_vreg(vgpu, offset) &= ~GMBUS_SW_CLR_INT;
+			reset_gmbus_controller(vgpu);
+		}
+		/*
+		 * TODO: "This bit is cleared to zero when an event
+		 * causes the HW_RDY bit transition to occur "
+		 */
+	} else {
+		/*
+		 * per bspec setting this bit can cause:
+		 * 1) INT status bit cleared
+		 * 2) HW_RDY bit asserted
+		 */
+		if (wvalue & GMBUS_SW_CLR_INT) {
+			vgpu_vreg(vgpu, PCH_GMBUS2) &= ~GMBUS_INT;
+			vgpu_vreg(vgpu, PCH_GMBUS2) |= GMBUS_HW_RDY;
+		}
+
+		/* For virtualization, we suppose that HW is always ready,
+		 * so GMBUS_SW_RDY should always be cleared
+		 */
+		if (wvalue & GMBUS_SW_RDY)
+			wvalue &= ~GMBUS_SW_RDY;
+
+		i2c_edid->gmbus.total_byte_count =
+			gmbus1_total_byte_count(wvalue);
+		slave_addr = gmbus1_slave_addr(wvalue);
+
+		/* vgpu gmbus only support EDID */
+		if (slave_addr == EDID_ADDR) {
+			i2c_edid->slave_selected = true;
+		} else if (slave_addr != 0) {
+			gvt_dbg_dpy(
+				"vgpu%d: unsupported gmbus slave addr(0x%x)\n"
+				"	gmbus operations will be ignored.\n",
+					vgpu->id, slave_addr);
+		}
+
+		if (wvalue & GMBUS_CYCLE_INDEX)
+			i2c_edid->current_edid_read =
+				gmbus1_slave_index(wvalue);
+
+		i2c_edid->gmbus.cycle_type = gmbus1_bus_cycle(wvalue);
+		switch (gmbus1_bus_cycle(wvalue)) {
+		case GMBUS_NOCYCLE:
+			break;
+		case GMBUS_STOP:
+			/* From spec:
+			 * This can only cause a STOP to be generated
+			 * if a GMBUS cycle is generated, the GMBUS is
+			 * currently in a data/wait/idle phase, or it is in a
+			 * WAIT phase
+			 */
+			if (gmbus1_bus_cycle(vgpu_vreg(vgpu, offset))
+				!= GMBUS_NOCYCLE) {
+				intel_vgpu_init_i2c_edid(vgpu);
+				/* After the 'stop' cycle, hw state would become
+				 * 'stop phase' and then 'idle phase' after a
+				 * few milliseconds. In emulation, we just set
+				 * it as 'idle phase' ('stop phase' is not
+				 * visible in gmbus interface)
+				 */
+				i2c_edid->gmbus.phase = GMBUS_IDLE_PHASE;
+				vgpu_vreg(vgpu, PCH_GMBUS2) &= ~GMBUS_ACTIVE;
+			}
+			break;
+		case NIDX_NS_W:
+		case IDX_NS_W:
+		case NIDX_STOP:
+		case IDX_STOP:
+			/* From hw spec the GMBUS phase
+			 * transition like this:
+			 * START (-->INDEX) -->DATA
+			 */
+			i2c_edid->gmbus.phase = GMBUS_DATA_PHASE;
+			vgpu_vreg(vgpu, PCH_GMBUS2) |= GMBUS_ACTIVE;
+			break;
+		default:
+			gvt_err("Unknown/reserved GMBUS cycle detected!\n");
+			break;
+		}
+		/*
+		 * From hw spec the WAIT state will be
+		 * cleared:
+		 * (1) in a new GMBUS cycle
+		 * (2) by generating a stop
+		 */
+		vgpu_vreg(vgpu, offset) = wvalue;
+	}
+	return 0;
+}
+
+static int gmbus3_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
+	void *p_data, unsigned int bytes)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static int gmbus3_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
+		void *p_data, unsigned int bytes)
+{
+	int i;
+	unsigned char byte_data;
+	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
+	int byte_left = i2c_edid->gmbus.total_byte_count -
+				i2c_edid->current_edid_read;
+	int byte_count = byte_left;
+	u32 reg_data = 0;
+
+	/* Data can only be recevied if previous settings correct */
+	if (vgpu_vreg(vgpu, PCH_GMBUS1) & GMBUS_SLAVE_READ) {
+		if (byte_left <= 0) {
+			memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
+			return 0;
+		}
+
+		if (byte_count > 4)
+			byte_count = 4;
+		for (i = 0; i < byte_count; i++) {
+			byte_data = edid_get_byte(vgpu);
+			reg_data |= (byte_data << (i << 3));
+		}
+
+		memcpy(&vgpu_vreg(vgpu, offset), &reg_data, byte_count);
+		memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
+
+		if (byte_left <= 4) {
+			switch (i2c_edid->gmbus.cycle_type) {
+			case NIDX_STOP:
+			case IDX_STOP:
+				i2c_edid->gmbus.phase = GMBUS_IDLE_PHASE;
+				break;
+			case NIDX_NS_W:
+			case IDX_NS_W:
+			default:
+				i2c_edid->gmbus.phase = GMBUS_WAIT_PHASE;
+				break;
+			}
+			intel_vgpu_init_i2c_edid(vgpu);
+		}
+		/*
+		 * Read GMBUS3 during send operation,
+		 * return the latest written value
+		 */
+	} else {
+		memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
+		gvt_err("vgpu%d: warning: gmbus3 read with nothing returned\n",
+				vgpu->id);
+	}
+	return 0;
+}
+
+static int gmbus2_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
+		void *p_data, unsigned int bytes)
+{
+	u32 value = vgpu_vreg(vgpu, offset);
+
+	if (!(vgpu_vreg(vgpu, offset) & GMBUS_INUSE))
+		vgpu_vreg(vgpu, offset) |= GMBUS_INUSE;
+	memcpy(p_data, (void *)&value, bytes);
+	return 0;
+}
+
+static int gmbus2_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
+		void *p_data, unsigned int bytes)
+{
+	u32 wvalue = *(u32 *)p_data;
+
+	if (wvalue & GMBUS_INUSE)
+		vgpu_vreg(vgpu, offset) &= ~GMBUS_INUSE;
+	/* All other bits are read-only */
+	return 0;
+}
+
+/**
+ * intel_gvt_i2c_handle_gmbus_read - emulate gmbus register mmio read
+ * @vgpu: a vGPU
+ *
+ * This function is used to emulate gmbus register mmio read
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_gvt_i2c_handle_gmbus_read(struct intel_vgpu *vgpu,
+	unsigned int offset, void *p_data, unsigned int bytes)
+{
+	if (WARN_ON(bytes > 8 && (offset & (bytes - 1))))
+		return -EINVAL;
+
+	if (offset == i915_mmio_reg_offset(PCH_GMBUS2))
+		return gmbus2_mmio_read(vgpu, offset, p_data, bytes);
+	else if (offset == i915_mmio_reg_offset(PCH_GMBUS3))
+		return gmbus3_mmio_read(vgpu, offset, p_data, bytes);
+
+	memcpy(p_data, &vgpu_vreg(vgpu, offset), bytes);
+	return 0;
+}
+
+/**
+ * intel_gvt_i2c_handle_gmbus_write - emulate gmbus register mmio write
+ * @vgpu: a vGPU
+ *
+ * This function is used to emulate gmbus register mmio write
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_gvt_i2c_handle_gmbus_write(struct intel_vgpu *vgpu,
+		unsigned int offset, void *p_data, unsigned int bytes)
+{
+	if (WARN_ON(bytes > 8 && (offset & (bytes - 1))))
+		return -EINVAL;
+
+	if (offset == i915_mmio_reg_offset(PCH_GMBUS0))
+		return gmbus0_mmio_write(vgpu, offset, p_data, bytes);
+	else if (offset == i915_mmio_reg_offset(PCH_GMBUS1))
+		return gmbus1_mmio_write(vgpu, offset, p_data, bytes);
+	else if (offset == i915_mmio_reg_offset(PCH_GMBUS2))
+		return gmbus2_mmio_write(vgpu, offset, p_data, bytes);
+	else if (offset == i915_mmio_reg_offset(PCH_GMBUS3))
+		return gmbus3_mmio_write(vgpu, offset, p_data, bytes);
+
+	memcpy(&vgpu_vreg(vgpu, offset), p_data, bytes);
+	return 0;
+}
+
+enum {
+	AUX_CH_CTL = 0,
+	AUX_CH_DATA1,
+	AUX_CH_DATA2,
+	AUX_CH_DATA3,
+	AUX_CH_DATA4,
+	AUX_CH_DATA5
+};
+
+static inline int get_aux_ch_reg(unsigned int offset)
+{
+	int reg;
+
+	switch (offset & 0xff) {
+	case 0x10:
+		reg = AUX_CH_CTL;
+		break;
+	case 0x14:
+		reg = AUX_CH_DATA1;
+		break;
+	case 0x18:
+		reg = AUX_CH_DATA2;
+		break;
+	case 0x1c:
+		reg = AUX_CH_DATA3;
+		break;
+	case 0x20:
+		reg = AUX_CH_DATA4;
+		break;
+	case 0x24:
+		reg = AUX_CH_DATA5;
+		break;
+	default:
+		reg = -1;
+		break;
+	}
+	return reg;
+}
+
+#define AUX_CTL_MSG_LENGTH(reg) \
+	((reg & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >> \
+		DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT)
+
+/**
+ * intel_gvt_i2c_handle_aux_ch_write - emulate AUX channel register write
+ * @vgpu: a vGPU
+ *
+ * This function is used to emulate AUX channel register write
+ *
+ */
+void intel_gvt_i2c_handle_aux_ch_write(struct intel_vgpu *vgpu,
+				int port_idx,
+				unsigned int offset,
+				void *p_data)
+{
+	struct intel_vgpu_i2c_edid *i2c_edid = &vgpu->display.i2c_edid;
+	int msg_length, ret_msg_size;
+	int msg, addr, ctrl, op;
+	u32 value = *(u32 *)p_data;
+	int aux_data_for_write = 0;
+	int reg = get_aux_ch_reg(offset);
+
+	if (reg != AUX_CH_CTL) {
+		vgpu_vreg(vgpu, offset) = value;
+		return;
+	}
+
+	msg_length = AUX_CTL_MSG_LENGTH(value);
+	// check the msg in DATA register.
+	msg = vgpu_vreg(vgpu, offset + 4);
+	addr = (msg >> 8) & 0xffff;
+	ctrl = (msg >> 24) & 0xff;
+	op = ctrl >> 4;
+	if (!(value & DP_AUX_CH_CTL_SEND_BUSY)) {
+		/* The ctl write to clear some states */
+		return;
+	}
+
+	/* Always set the wanted value for vms. */
+	ret_msg_size = (((op & 0x1) == GVT_AUX_I2C_READ) ? 2 : 1);
+	vgpu_vreg(vgpu, offset) =
+		DP_AUX_CH_CTL_DONE |
+		((ret_msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) &
+		DP_AUX_CH_CTL_MESSAGE_SIZE_MASK);
+
+	if (msg_length == 3) {
+		if (!(op & GVT_AUX_I2C_MOT)) {
+			/* stop */
+			intel_vgpu_init_i2c_edid(vgpu);
+		} else {
+			/* start or restart */
+			i2c_edid->aux_ch.i2c_over_aux_ch = true;
+			i2c_edid->aux_ch.aux_ch_mot = true;
+			if (addr == 0) {
+				/* reset the address */
+				intel_vgpu_init_i2c_edid(vgpu);
+			} else if (addr == EDID_ADDR) {
+				i2c_edid->state = I2C_AUX_CH;
+				i2c_edid->port = port_idx;
+				i2c_edid->slave_selected = true;
+				if (intel_vgpu_has_monitor_on_port(vgpu,
+					port_idx) &&
+					intel_vgpu_port_is_dp(vgpu, port_idx))
+					i2c_edid->edid_available = true;
+			}
+		}
+	} else if ((op & 0x1) == GVT_AUX_I2C_WRITE) {
+		/* TODO
+		 * We only support EDID reading from I2C_over_AUX. And
+		 * we do not expect the index mode to be used. Right now
+		 * the WRITE operation is ignored. It is good enough to
+		 * suppor