Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

6 files changed, 791 insertions, 0 deletions

diff --git a/drivers/gpu/drm/aspeed/Kconfig b/drivers/gpu/drm/aspeed/Kconfig
new file mode 100644
index 000000000..6e68f20aa
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config DRM_ASPEED_GFX
+	tristate "ASPEED BMC Display Controller"
+	depends on DRM && OF
+	depends on (COMPILE_TEST || ARCH_ASPEED)
+	depends on MMU
+	select DRM_CLIENT_SELECTION
+	select DRM_KMS_HELPER
+	select DRM_GEM_DMA_HELPER
+	select DMA_CMA if HAVE_DMA_CONTIGUOUS
+	select CMA if HAVE_DMA_CONTIGUOUS
+	select MFD_SYSCON
+	help
+	  Chose this option if you have an ASPEED AST2500 SOC Display
+	  Controller (aka GFX).
+
+	  If M is selected this module will be called aspeed_gfx.
diff --git a/drivers/gpu/drm/aspeed/Makefile b/drivers/gpu/drm/aspeed/Makefile
new file mode 100644
index 000000000..a681ba3cc
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+aspeed_gfx-y := aspeed_gfx_drv.o aspeed_gfx_crtc.o aspeed_gfx_out.o
+
+obj-$(CONFIG_DRM_ASPEED_GFX) += aspeed_gfx.o
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
new file mode 100644
index 000000000..4e6a442c3
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Copyright 2018 IBM Corporation */
+
+#include <drm/drm_device.h>
+#include <drm/drm_simple_kms_helper.h>
+
+struct aspeed_gfx {
+	struct drm_device		drm;
+	void __iomem			*base;
+	struct clk			*clk;
+	struct reset_control		*rst;
+	struct regmap			*scu;
+
+	u32				dac_reg;
+	u32				int_clr_reg;
+	u32				vga_scratch_reg;
+	u32				throd_val;
+	u32				scan_line_max;
+
+	struct drm_simple_display_pipe	pipe;
+	struct drm_connector		connector;
+};
+#define to_aspeed_gfx(x) container_of(x, struct aspeed_gfx, drm)
+
+int aspeed_gfx_create_pipe(struct drm_device *drm);
+int aspeed_gfx_create_output(struct drm_device *drm);
+
+#define CRT_CTRL1		0x60 /* CRT Control I */
+#define CRT_CTRL2		0x64 /* CRT Control II */
+#define CRT_STATUS		0x68 /* CRT Status */
+#define CRT_MISC		0x6c /* CRT Misc Setting */
+#define CRT_HORIZ0		0x70 /* CRT Horizontal Total & Display Enable End */
+#define CRT_HORIZ1		0x74 /* CRT Horizontal Retrace Start & End */
+#define CRT_VERT0		0x78 /* CRT Vertical Total & Display Enable End */
+#define CRT_VERT1		0x7C /* CRT Vertical Retrace Start & End */
+#define CRT_ADDR		0x80 /* CRT Display Starting Address */
+#define CRT_OFFSET		0x84 /* CRT Display Offset & Terminal Count */
+#define CRT_THROD		0x88 /* CRT Threshold */
+#define CRT_XSCALE		0x8C /* CRT Scaling-Up Factor */
+#define CRT_CURSOR0		0x90 /* CRT Hardware Cursor X & Y Offset */
+#define CRT_CURSOR1		0x94 /* CRT Hardware Cursor X & Y Position */
+#define CRT_CURSOR2		0x98 /* CRT Hardware Cursor Pattern Address */
+#define CRT_9C			0x9C
+#define CRT_OSD_H		0xA0 /* CRT OSD Horizontal Start/End */
+#define CRT_OSD_V		0xA4 /* CRT OSD Vertical Start/End */
+#define CRT_OSD_ADDR		0xA8 /* CRT OSD Pattern Address */
+#define CRT_OSD_DISP		0xAC /* CRT OSD Offset */
+#define CRT_OSD_THRESH		0xB0 /* CRT OSD Threshold & Alpha */
+#define CRT_B4			0xB4
+#define CRT_STS_V		0xB8 /* CRT Status V */
+#define CRT_SCRATCH		0xBC /* Scratchpad */
+#define CRT_BB0_ADDR		0xD0 /* CRT Display BB0 Starting Address */
+#define CRT_BB1_ADDR		0xD4 /* CRT Display BB1 Starting Address */
+#define CRT_BB_COUNT		0xD8 /* CRT Display BB Terminal Count */
+#define OSD_COLOR1		0xE0 /* OSD Color Palette Index 1 & 0 */
+#define OSD_COLOR2		0xE4 /* OSD Color Palette Index 3 & 2 */
+#define OSD_COLOR3		0xE8 /* OSD Color Palette Index 5 & 4 */
+#define OSD_COLOR4		0xEC /* OSD Color Palette Index 7 & 6 */
+#define OSD_COLOR5		0xF0 /* OSD Color Palette Index 9 & 8 */
+#define OSD_COLOR6		0xF4 /* OSD Color Palette Index 11 & 10 */
+#define OSD_COLOR7		0xF8 /* OSD Color Palette Index 13 & 12 */
+#define OSD_COLOR8		0xFC /* OSD Color Palette Index 15 & 14 */
+
+/* CTRL1 */
+#define CRT_CTRL_EN			BIT(0)
+#define CRT_CTRL_HW_CURSOR_EN		BIT(1)
+#define CRT_CTRL_OSD_EN			BIT(2)
+#define CRT_CTRL_INTERLACED		BIT(3)
+#define CRT_CTRL_COLOR_RGB565		(0 << 7)
+#define CRT_CTRL_COLOR_YUV444		(1 << 7)
+#define CRT_CTRL_COLOR_XRGB8888		(2 << 7)
+#define CRT_CTRL_COLOR_RGB888		(3 << 7)
+#define CRT_CTRL_COLOR_YUV444_2RGB	(5 << 7)
+#define CRT_CTRL_COLOR_YUV422		(7 << 7)
+#define CRT_CTRL_COLOR_MASK		GENMASK(9, 7)
+#define CRT_CTRL_HSYNC_NEGATIVE		BIT(16)
+#define CRT_CTRL_VSYNC_NEGATIVE		BIT(17)
+#define CRT_CTRL_VERTICAL_INTR_EN	BIT(30)
+#define CRT_CTRL_VERTICAL_INTR_STS	BIT(31)
+
+/* CTRL2 */
+#define CRT_CTRL_DAC_EN			BIT(0)
+#define CRT_CTRL_VBLANK_LINE(x)		(((x) << 20) & CRT_CTRL_VBLANK_LINE_MASK)
+#define CRT_CTRL_VBLANK_LINE_MASK	GENMASK(31, 20)
+
+/* CRT_HORIZ0 */
+#define CRT_H_TOTAL(x)			(x)
+#define CRT_H_DE(x)			((x) << 16)
+
+/* CRT_HORIZ1 */
+#define CRT_H_RS_START(x)		(x)
+#define CRT_H_RS_END(x)			((x) << 16)
+
+/* CRT_VIRT0 */
+#define CRT_V_TOTAL(x)			(x)
+#define CRT_V_DE(x)			((x) << 16)
+
+/* CRT_VIRT1 */
+#define CRT_V_RS_START(x)		(x)
+#define CRT_V_RS_END(x)			((x) << 16)
+
+/* CRT_OFFSET */
+#define CRT_DISP_OFFSET(x)		(x)
+#define CRT_TERM_COUNT(x)		((x) << 16)
+
+/* CRT_THROD */
+#define CRT_THROD_LOW(x)		(x)
+#define CRT_THROD_HIGH(x)		((x) << 8)
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
new file mode 100644
index 000000000..7877a57b8
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2018 IBM Corporation
+
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_device.h>
+#include <drm/drm_fb_dma_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_simple_kms_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "aspeed_gfx.h"
+
+static struct aspeed_gfx *
+drm_pipe_to_aspeed_gfx(struct drm_simple_display_pipe *pipe)
+{
+	return container_of(pipe, struct aspeed_gfx, pipe);
+}
+
+static int aspeed_gfx_set_pixel_fmt(struct aspeed_gfx *priv, u32 *bpp)
+{
+	struct drm_crtc *crtc = &priv->pipe.crtc;
+	struct drm_device *drm = crtc->dev;
+	const u32 format = crtc->primary->state->fb->format->format;
+	u32 ctrl1;
+
+	ctrl1 = readl(priv->base + CRT_CTRL1);
+	ctrl1 &= ~CRT_CTRL_COLOR_MASK;
+
+	switch (format) {
+	case DRM_FORMAT_RGB565:
+		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
+		ctrl1 |= CRT_CTRL_COLOR_RGB565;
+		*bpp = 16;
+		break;
+	case DRM_FORMAT_XRGB8888:
+		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
+		ctrl1 |= CRT_CTRL_COLOR_XRGB8888;
+		*bpp = 32;
+		break;
+	default:
+		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
+		return -EINVAL;
+	}
+
+	writel(ctrl1, priv->base + CRT_CTRL1);
+
+	return 0;
+}
+
+static void aspeed_gfx_enable_controller(struct aspeed_gfx *priv)
+{
+	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
+	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
+
+	/* Set DAC source for display output to Graphics CRT (GFX) */
+	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), BIT(16));
+
+	writel(ctrl1 | CRT_CTRL_EN, priv->base + CRT_CTRL1);
+	writel(ctrl2 | CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
+}
+
+static void aspeed_gfx_disable_controller(struct aspeed_gfx *priv)
+{
+	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
+	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
+
+	writel(ctrl1 & ~CRT_CTRL_EN, priv->base + CRT_CTRL1);
+	writel(ctrl2 & ~CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
+
+	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), 0);
+}
+
+static void aspeed_gfx_crtc_mode_set_nofb(struct aspeed_gfx *priv)
+{
+	struct drm_display_mode *m = &priv->pipe.crtc.state->adjusted_mode;
+	u32 ctrl1, d_offset, t_count, bpp;
+	int err;
+
+	err = aspeed_gfx_set_pixel_fmt(priv, &bpp);
+	if (err)
+		return;
+
+#if 0
+	/* TODO: we have only been able to test with the 40MHz USB clock. The
+	 * clock is fixed, so we cannot adjust it here. */
+	clk_set_rate(priv->pixel_clk, m->crtc_clock * 1000);
+#endif
+
+	ctrl1 = readl(priv->base + CRT_CTRL1);
+	ctrl1 &= ~(CRT_CTRL_INTERLACED |
+			CRT_CTRL_HSYNC_NEGATIVE |
+			CRT_CTRL_VSYNC_NEGATIVE);
+
+	if (m->flags & DRM_MODE_FLAG_INTERLACE)
+		ctrl1 |= CRT_CTRL_INTERLACED;
+
+	if (!(m->flags & DRM_MODE_FLAG_PHSYNC))
+		ctrl1 |= CRT_CTRL_HSYNC_NEGATIVE;
+
+	if (!(m->flags & DRM_MODE_FLAG_PVSYNC))
+		ctrl1 |= CRT_CTRL_VSYNC_NEGATIVE;
+
+	writel(ctrl1, priv->base + CRT_CTRL1);
+
+	/* Horizontal timing */
+	writel(CRT_H_TOTAL(m->htotal - 1) | CRT_H_DE(m->hdisplay - 1),
+			priv->base + CRT_HORIZ0);
+	writel(CRT_H_RS_START(m->hsync_start - 1) | CRT_H_RS_END(m->hsync_end),
+			priv->base + CRT_HORIZ1);
+
+
+	/* Vertical timing */
+	writel(CRT_V_TOTAL(m->vtotal - 1) | CRT_V_DE(m->vdisplay - 1),
+			priv->base + CRT_VERT0);
+	writel(CRT_V_RS_START(m->vsync_start) | CRT_V_RS_END(m->vsync_end),
+			priv->base + CRT_VERT1);
+
+	/*
+	 * Display Offset: address difference between consecutive scan lines
+	 * Terminal Count: memory size of one scan line
+	 */
+	d_offset = m->hdisplay * bpp / 8;
+	t_count = DIV_ROUND_UP(m->hdisplay * bpp, priv->scan_line_max);
+
+	writel(CRT_DISP_OFFSET(d_offset) | CRT_TERM_COUNT(t_count),
+			priv->base + CRT_OFFSET);
+
+	/*
+	 * Threshold: FIFO thresholds of refill and stop (16 byte chunks
+	 * per line, rounded up)
+	 */
+	writel(priv->throd_val, priv->base + CRT_THROD);
+}
+
+static void aspeed_gfx_pipe_enable(struct drm_simple_display_pipe *pipe,
+			      struct drm_crtc_state *crtc_state,
+			      struct drm_plane_state *plane_state)
+{
+	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
+	struct drm_crtc *crtc = &pipe->crtc;
+
+	aspeed_gfx_crtc_mode_set_nofb(priv);
+	aspeed_gfx_enable_controller(priv);
+	drm_crtc_vblank_on(crtc);
+}
+
+static void aspeed_gfx_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
+	struct drm_crtc *crtc = &pipe->crtc;
+
+	drm_crtc_vblank_off(crtc);
+	aspeed_gfx_disable_controller(priv);
+}
+
+static void aspeed_gfx_pipe_update(struct drm_simple_display_pipe *pipe,
+				   struct drm_plane_state *plane_state)
+{
+	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_framebuffer *fb = pipe->plane.state->fb;
+	struct drm_pending_vblank_event *event;
+	struct drm_gem_dma_object *gem;
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	event = crtc->state->event;
+	if (event) {
+		crtc->state->event = NULL;
+
+		if (drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, event);
+		else
+			drm_crtc_send_vblank_event(crtc, event);
+	}
+	spin_unlock_irq(&crtc->dev->event_lock);
+
+	if (!fb)
+		return;
+
+	gem = drm_fb_dma_get_gem_obj(fb, 0);
+	if (!gem)
+		return;
+	writel(gem->dma_addr, priv->base + CRT_ADDR);
+}
+
+static int aspeed_gfx_enable_vblank(struct drm_simple_display_pipe *pipe)
+{
+	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
+	u32 reg = readl(priv->base + CRT_CTRL1);
+
+	/* Clear pending VBLANK IRQ */
+	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
+
+	reg |= CRT_CTRL_VERTICAL_INTR_EN;
+	writel(reg, priv->base + CRT_CTRL1);
+
+	return 0;
+}
+
+static void aspeed_gfx_disable_vblank(struct drm_simple_display_pipe *pipe)
+{
+	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
+	u32 reg = readl(priv->base + CRT_CTRL1);
+
+	reg &= ~CRT_CTRL_VERTICAL_INTR_EN;
+	writel(reg, priv->base + CRT_CTRL1);
+
+	/* Clear pending VBLANK IRQ */
+	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
+}
+
+static const struct drm_simple_display_pipe_funcs aspeed_gfx_funcs = {
+	.enable		= aspeed_gfx_pipe_enable,
+	.disable	= aspeed_gfx_pipe_disable,
+	.update		= aspeed_gfx_pipe_update,
+	.enable_vblank	= aspeed_gfx_enable_vblank,
+	.disable_vblank	= aspeed_gfx_disable_vblank,
+};
+
+static const uint32_t aspeed_gfx_formats[] = {
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_RGB565,
+};
+
+int aspeed_gfx_create_pipe(struct drm_device *drm)
+{
+	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
+
+	return drm_simple_display_pipe_init(drm, &priv->pipe, &aspeed_gfx_funcs,
+					    aspeed_gfx_formats,
+					    ARRAY_SIZE(aspeed_gfx_formats),
+					    NULL,
+					    &priv->connector);
+}
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
new file mode 100644
index 000000000..d4577663a
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2018 IBM Corporation
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/irq.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include <drm/clients/drm_client_setup.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_fbdev_dma.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_module.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+#include <drm/drm_vblank.h>
+#include <drm/drm_drv.h>
+
+#include "aspeed_gfx.h"
+
+/**
+ * DOC: ASPEED GFX Driver
+ *
+ * This driver is for the ASPEED BMC SoC's 'GFX' display hardware, also called
+ * the 'SOC Display Controller' in the datasheet. This driver runs on the ARM
+ * based BMC systems, unlike the ast driver which runs on a host CPU and is for
+ * a PCIe graphics device.
+ *
+ * The AST2500 supports a total of 3 output paths:
+ *
+ *   1. VGA output, the output target can choose either or both to the DAC
+ *   or DVO interface.
+ *
+ *   2. Graphics CRT output, the output target can choose either or both to
+ *   the DAC or DVO interface.
+ *
+ *   3. Video input from DVO, the video input can be used for video engine
+ *   capture or DAC display output.
+ *
+ * Output options are selected in SCU2C.
+ *
+ * The "VGA mode" device is the PCI attached controller. The "Graphics CRT"
+ * is the ARM's internal display controller.
+ *
+ * The driver only supports a simple configuration consisting of a 40MHz
+ * pixel clock, fixed by hardware limitations, and the VGA output path.
+ *
+ * The driver was written with the 'AST2500 Software Programming Guide' v17,
+ * which is available under NDA from ASPEED.
+ */
+
+struct aspeed_gfx_config {
+	u32 dac_reg;		/* DAC register in SCU */
+	u32 int_clear_reg;	/* Interrupt clear register */
+	u32 vga_scratch_reg;	/* VGA scratch register in SCU */
+	u32 throd_val;		/* Default Threshold Seting */
+	u32 scan_line_max;	/* Max memory size of one scan line */
+};
+
+static const struct aspeed_gfx_config ast2400_config = {
+	.dac_reg = 0x2c,
+	.int_clear_reg = 0x60,
+	.vga_scratch_reg = 0x50,
+	.throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12),
+	.scan_line_max = 64,
+};
+
+static const struct aspeed_gfx_config ast2500_config = {
+	.dac_reg = 0x2c,
+	.int_clear_reg = 0x60,
+	.vga_scratch_reg = 0x50,
+	.throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c),
+	.scan_line_max = 128,
+};
+
+static const struct aspeed_gfx_config ast2600_config = {
+	.dac_reg = 0xc0,
+	.int_clear_reg = 0x68,
+	.vga_scratch_reg = 0x50,
+	.throd_val = CRT_THROD_LOW(0x50) | CRT_THROD_HIGH(0x70),
+	.scan_line_max = 128,
+};
+
+static const struct of_device_id aspeed_gfx_match[] = {
+	{ .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config },
+	{ .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config },
+	{ .compatible = "aspeed,ast2600-gfx", .data = &ast2600_config },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, aspeed_gfx_match);
+
+static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = {
+	.fb_create		= drm_gem_fb_create,
+	.atomic_check		= drm_atomic_helper_check,
+	.atomic_commit		= drm_atomic_helper_commit,
+};
+
+static int aspeed_gfx_setup_mode_config(struct drm_device *drm)
+{
+	int ret;
+
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ret;
+
+	drm->mode_config.min_width = 0;
+	drm->mode_config.min_height = 0;
+	drm->mode_config.max_width = 800;
+	drm->mode_config.max_height = 600;
+	drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
+
+	return ret;
+}
+
+static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
+{
+	struct drm_device *drm = data;
+	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
+	u32 reg;
+
+	reg = readl(priv->base + CRT_CTRL1);
+
+	if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
+		drm_crtc_handle_vblank(&priv->pipe.crtc);
+		writel(reg, priv->base + priv->int_clr_reg);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int aspeed_gfx_load(struct drm_device *drm)
+{
+	struct platform_device *pdev = to_platform_device(drm->dev);
+	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
+	struct device_node *np = pdev->dev.of_node;
+	const struct aspeed_gfx_config *config;
+	int ret;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	config = device_get_match_data(&pdev->dev);
+	if (!config)
+		return -EINVAL;
+
+	priv->dac_reg = config->dac_reg;
+	priv->int_clr_reg = config->int_clear_reg;
+	priv->vga_scratch_reg = config->vga_scratch_reg;
+	priv->throd_val = config->throd_val;
+	priv->scan_line_max = config->scan_line_max;
+
+	priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
+	if (IS_ERR(priv->scu)) {
+		priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
+		if (IS_ERR(priv->scu)) {
+			dev_err(&pdev->dev, "failed to find SCU regmap\n");
+			return PTR_ERR(priv->scu);
+		}
+	}
+
+	ret = of_reserved_mem_device_init(drm->dev);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"failed to initialize reserved mem: %d\n", ret);
+		return ret;
+	}
+
+	ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
+		return ret;
+	}
+
+	priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(priv->rst)) {
+		dev_err(&pdev->dev,
+			"missing or invalid reset controller device tree entry");
+		return PTR_ERR(priv->rst);
+	}
+	reset_control_deassert(priv->rst);
+
+	priv->clk = devm_clk_get(drm->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(&pdev->dev,
+			"missing or invalid clk device tree entry");
+		return PTR_ERR(priv->clk);
+	}
+	clk_prepare_enable(priv->clk);
+
+	/* Sanitize control registers */
+	writel(0, priv->base + CRT_CTRL1);
+	writel(0, priv->base + CRT_CTRL2);
+
+	ret = aspeed_gfx_setup_mode_config(drm);
+	if (ret < 0)
+		return ret;
+
+	ret = drm_vblank_init(drm, 1);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to initialise vblank\n");
+		return ret;
+	}
+
+	ret = aspeed_gfx_create_output(drm);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to create outputs\n");
+		return ret;
+	}
+
+	ret = aspeed_gfx_create_pipe(drm);
+	if (ret < 0) {
+		dev_err(drm->dev, "Cannot setup simple display pipe\n");
+		return ret;
+	}
+
+	ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
+			       aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to install IRQ handler\n");
+		return ret;
+	}
+
+	drm_mode_config_reset(drm);
+
+	return 0;
+}
+
+static void aspeed_gfx_unload(struct drm_device *drm)
+{
+	drm_kms_helper_poll_fini(drm);
+}
+
+DEFINE_DRM_GEM_DMA_FOPS(fops);
+
+static const struct drm_driver aspeed_gfx_driver = {
+	.driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+	DRM_GEM_DMA_DRIVER_OPS,
+	DRM_FBDEV_DMA_DRIVER_OPS,
+	.fops = &fops,
+	.name = "aspeed-gfx-drm",
+	.desc = "ASPEED GFX DRM",
+	.major = 1,
+	.minor = 0,
+};
+
+static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct aspeed_gfx *priv = dev_get_drvdata(dev);
+	u32 val;
+	int rc;
+
+	rc = kstrtou32(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	if (val > 3)
+		return -EINVAL;
+
+	rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
+	if (rc < 0)
+		return 0;
+
+	return count;
+}
+
+static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct aspeed_gfx *priv = dev_get_drvdata(dev);
+	u32 reg;
+	int rc;
+
+	rc = regmap_read(priv->scu, priv->dac_reg, &reg);
+	if (rc)
+		return rc;
+
+	return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
+}
+static DEVICE_ATTR_RW(dac_mux);
+
+static ssize_t
+vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct aspeed_gfx *priv = dev_get_drvdata(dev);
+	u32 reg;
+	int rc;
+
+	rc = regmap_read(priv->scu, priv->vga_scratch_reg, &reg);
+	if (rc)
+		return rc;
+
+	return sprintf(buf, "%u\n", reg);
+}
+static DEVICE_ATTR_RO(vga_pw);
+
+static struct attribute *aspeed_sysfs_entries[] = {
+	&dev_attr_vga_pw.attr,
+	&dev_attr_dac_mux.attr,
+	NULL,
+};
+
+static struct attribute_group aspeed_sysfs_attr_group = {
+	.attrs = aspeed_sysfs_entries,
+};
+
+static int aspeed_gfx_probe(struct platform_device *pdev)
+{
+	struct aspeed_gfx *priv;
+	int ret;
+
+	priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
+				  struct aspeed_gfx, drm);
+	if (IS_ERR(priv))
+		return PTR_ERR(priv);
+
+	ret = aspeed_gfx_load(&priv->drm);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
+	if (ret)
+		return ret;
+
+	ret = drm_dev_register(&priv->drm, 0);
+	if (ret)
+		goto err_unload;
+
+	drm_client_setup(&priv->drm, NULL);
+	return 0;
+
+err_unload:
+	sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
+	aspeed_gfx_unload(&priv->drm);
+
+	return ret;
+}
+
+static void aspeed_gfx_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
+	drm_dev_unregister(drm);
+	aspeed_gfx_unload(drm);
+	drm_atomic_helper_shutdown(drm);
+}
+
+static void aspeed_gfx_shutdown(struct platform_device *pdev)
+{
+	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
+}
+
+static struct platform_driver aspeed_gfx_platform_driver = {
+	.probe		= aspeed_gfx_probe,
+	.remove		= aspeed_gfx_remove,
+	.shutdown	= aspeed_gfx_shutdown,
+	.driver = {
+		.name = "aspeed_gfx",
+		.of_match_table = aspeed_gfx_match,
+	},
+};
+
+drm_module_platform_driver(aspeed_gfx_platform_driver);
+
+MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
+MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_out.c b/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
new file mode 100644
index 000000000..78775e0c8
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2018 IBM Corporation
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_probe_helper.h>
+
+#include "aspeed_gfx.h"
+
+static int aspeed_gfx_get_modes(struct drm_connector *connector)
+{
+	return drm_add_modes_noedid(connector, 800, 600);
+}
+
+static const struct
+drm_connector_helper_funcs aspeed_gfx_connector_helper_funcs = {
+	.get_modes = aspeed_gfx_get_modes,
+};
+
+static const struct drm_connector_funcs aspeed_gfx_connector_funcs = {
+	.fill_modes		= drm_helper_probe_single_connector_modes,
+	.destroy		= drm_connector_cleanup,
+	.reset			= drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+};
+
+int aspeed_gfx_create_output(struct drm_device *drm)
+{
+	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
+	int ret;
+
+	priv->connector.dpms = DRM_MODE_DPMS_OFF;
+	priv->connector.polled = 0;
+	drm_connector_helper_add(&priv->connector,
+				 &aspeed_gfx_connector_helper_funcs);
+	ret = drm_connector_init(drm, &priv->connector,
+				 &aspeed_gfx_connector_funcs,
+				 DRM_MODE_CONNECTOR_Unknown);
+	return ret;
+}