[Intel-gfx] [PATCH 6/6] drm/i915: Move pipecrc debug functions to new file

Ben Widawsky benjamin.widawsky at intel.com
Tue Jan 21 21:33:22 CET 2014


At almost 800 lines of code, with almost a function per platform, this
code was cluttering up the existing debugfs file, which has
historically had fairly small functions.

Patch should have no functional changes.

Unfortunately, the patch Daniel requested of me for the DRM helper
doesn't fit well with how we enable the CRC. Unlike most users of the
interface, the CRC debugfs uses a separate fops and key. Instead of
catering the interface to the one user, keep the CRC code the same as
before, but embed the function that we don't want others to use (unless
they have a good reason).

v2: Remove spurious #if 0 (Damien)
Rename to intel_display_test.c (Damien)
Inline the drm_info_fake_node_add, since the DRM helper function should
solve most users problem (Ben)

Cc: Damien Lespiau <damien.lespiau at intel.com>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/Makefile             |   2 +-
 drivers/gpu/drm/i915/i915_debugfs.c       | 790 -----------------------------
 drivers/gpu/drm/i915/i915_drv.h           |  12 +
 drivers/gpu/drm/i915/intel_display_test.c | 801 ++++++++++++++++++++++++++++++
 4 files changed, 814 insertions(+), 791 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_display_test.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index da682cb..248ec41 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -54,7 +54,7 @@ i915-$(CONFIG_ACPI)	+= intel_acpi.o
 
 i915-$(CONFIG_DRM_I915_FBDEV) += intel_fbdev.o
 
-i915-$(CONFIG_DEBUG_FS) += i915_debugfs.o
+i915-$(CONFIG_DEBUG_FS) += i915_debugfs.o intel_display_test.o
 
 obj-$(CONFIG_DRM_I915)  += i915.o
 
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index d092631..4c3382a 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -27,8 +27,6 @@
  */
 
 #include <linux/seq_file.h>
-#include <linux/circ_buf.h>
-#include <linux/ctype.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
 #include <linux/export.h>
@@ -51,32 +49,6 @@ static const char *yesno(int v)
 	return v ? "yes" : "no";
 }
 
-/* As the drm_debugfs_init() routines are called before dev->dev_private is
- * allocated we need to hook into the minor for release. */
-static int
-drm_add_fake_info_node(struct drm_minor *minor,
-		       struct dentry *ent,
-		       const void *key)
-{
-	struct drm_info_node *node;
-
-	node = kmalloc(sizeof(*node), GFP_KERNEL);
-	if (node == NULL) {
-		debugfs_remove(ent);
-		return -ENOMEM;
-	}
-
-	node->minor = minor;
-	node->dent = ent;
-	node->info_ent = (void *) key;
-
-	mutex_lock(&minor->debugfs_lock);
-	list_add(&node->list, &minor->debugfs_list);
-	mutex_unlock(&minor->debugfs_lock);
-
-	return 0;
-}
-
 static int i915_capabilities(struct seq_file *m, void *data)
 {
 	struct drm_info_node *node = (struct drm_info_node *) m->private;
@@ -2036,754 +2008,6 @@ static int i915_power_domain_info(struct seq_file *m, void *unused)
 	return 0;
 }
 
-struct pipe_crc_info {
-	const char *name;
-	struct drm_device *dev;
-	enum pipe pipe;
-};
-
-static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
-{
-	struct pipe_crc_info *info = inode->i_private;
-	struct drm_i915_private *dev_priv = info->dev->dev_private;
-	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
-
-	if (info->pipe >= INTEL_INFO(info->dev)->num_pipes)
-		return -ENODEV;
-
-	spin_lock_irq(&pipe_crc->lock);
-
-	if (pipe_crc->opened) {
-		spin_unlock_irq(&pipe_crc->lock);
-		return -EBUSY; /* already open */
-	}
-
-	pipe_crc->opened = true;
-	filep->private_data = inode->i_private;
-
-	spin_unlock_irq(&pipe_crc->lock);
-
-	return 0;
-}
-
-static int i915_pipe_crc_release(struct inode *inode, struct file *filep)
-{
-	struct pipe_crc_info *info = inode->i_private;
-	struct drm_i915_private *dev_priv = info->dev->dev_private;
-	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
-
-	spin_lock_irq(&pipe_crc->lock);
-	pipe_crc->opened = false;
-	spin_unlock_irq(&pipe_crc->lock);
-
-	return 0;
-}
-
-/* (6 fields, 8 chars each, space separated (5) + '\n') */
-#define PIPE_CRC_LINE_LEN	(6 * 8 + 5 + 1)
-/* account for \'0' */
-#define PIPE_CRC_BUFFER_LEN	(PIPE_CRC_LINE_LEN + 1)
-
-static int pipe_crc_data_count(struct intel_pipe_crc *pipe_crc)
-{
-	assert_spin_locked(&pipe_crc->lock);
-	return CIRC_CNT(pipe_crc->head, pipe_crc->tail,
-			INTEL_PIPE_CRC_ENTRIES_NR);
-}
-
-static ssize_t
-i915_pipe_crc_read(struct file *filep, char __user *user_buf, size_t count,
-		   loff_t *pos)
-{
-	struct pipe_crc_info *info = filep->private_data;
-	struct drm_device *dev = info->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
-	char buf[PIPE_CRC_BUFFER_LEN];
-	int head, tail, n_entries, n;
-	ssize_t bytes_read;
-
-	/*
-	 * Don't allow user space to provide buffers not big enough to hold
-	 * a line of data.
-	 */
-	if (count < PIPE_CRC_LINE_LEN)
-		return -EINVAL;
-
-	if (pipe_crc->source == INTEL_PIPE_CRC_SOURCE_NONE)
-		return 0;
-
-	/* nothing to read */
-	spin_lock_irq(&pipe_crc->lock);
-	while (pipe_crc_data_count(pipe_crc) == 0) {
-		int ret;
-
-		if (filep->f_flags & O_NONBLOCK) {
-			spin_unlock_irq(&pipe_crc->lock);
-			return -EAGAIN;
-		}
-
-		ret = wait_event_interruptible_lock_irq(pipe_crc->wq,
-				pipe_crc_data_count(pipe_crc), pipe_crc->lock);
-		if (ret) {
-			spin_unlock_irq(&pipe_crc->lock);
-			return ret;
-		}
-	}
-
-	/* We now have one or more entries to read */
-	head = pipe_crc->head;
-	tail = pipe_crc->tail;
-	n_entries = min((size_t)CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR),
-			count / PIPE_CRC_LINE_LEN);
-	spin_unlock_irq(&pipe_crc->lock);
-
-	bytes_read = 0;
-	n = 0;
-	do {
-		struct intel_pipe_crc_entry *entry = &pipe_crc->entries[tail];
-		int ret;
-
-		bytes_read += snprintf(buf, PIPE_CRC_BUFFER_LEN,
-				       "%8u %8x %8x %8x %8x %8x\n",
-				       entry->frame, entry->crc[0],
-				       entry->crc[1], entry->crc[2],
-				       entry->crc[3], entry->crc[4]);
-
-		ret = copy_to_user(user_buf + n * PIPE_CRC_LINE_LEN,
-				   buf, PIPE_CRC_LINE_LEN);
-		if (ret == PIPE_CRC_LINE_LEN)
-			return -EFAULT;
-
-		BUILD_BUG_ON_NOT_POWER_OF_2(INTEL_PIPE_CRC_ENTRIES_NR);
-		tail = (tail + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
-		n++;
-	} while (--n_entries);
-
-	spin_lock_irq(&pipe_crc->lock);
-	pipe_crc->tail = tail;
-	spin_unlock_irq(&pipe_crc->lock);
-
-	return bytes_read;
-}
-
-static const struct file_operations i915_pipe_crc_fops = {
-	.owner = THIS_MODULE,
-	.open = i915_pipe_crc_open,
-	.read = i915_pipe_crc_read,
-	.release = i915_pipe_crc_release,
-};
-
-static struct pipe_crc_info i915_pipe_crc_data[I915_MAX_PIPES] = {
-	{
-		.name = "i915_pipe_A_crc",
-		.pipe = PIPE_A,
-	},
-	{
-		.name = "i915_pipe_B_crc",
-		.pipe = PIPE_B,
-	},
-	{
-		.name = "i915_pipe_C_crc",
-		.pipe = PIPE_C,
-	},
-};
-
-static int i915_pipe_crc_create(struct dentry *root, struct drm_minor *minor,
-				enum pipe pipe)
-{
-	struct drm_device *dev = minor->dev;
-	struct dentry *ent;
-	struct pipe_crc_info *info = &i915_pipe_crc_data[pipe];
-
-	info->dev = dev;
-	ent = debugfs_create_file(info->name, S_IRUGO, root, info,
-				  &i915_pipe_crc_fops);
-	if (!ent)
-		return -ENOMEM;
-
-	return drm_add_fake_info_node(minor, ent, info);
-}
-
-static const char * const pipe_crc_sources[] = {
-	"none",
-	"plane1",
-	"plane2",
-	"pf",
-	"pipe",
-	"TV",
-	"DP-B",
-	"DP-C",
-	"DP-D",
-	"auto",
-};
-
-static const char *pipe_crc_source_name(enum intel_pipe_crc_source source)
-{
-	BUILD_BUG_ON(ARRAY_SIZE(pipe_crc_sources) != INTEL_PIPE_CRC_SOURCE_MAX);
-	return pipe_crc_sources[source];
-}
-
-static int display_crc_ctl_show(struct seq_file *m, void *data)
-{
-	struct drm_device *dev = m->private;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	int i;
-
-	for (i = 0; i < I915_MAX_PIPES; i++)
-		seq_printf(m, "%c %s\n", pipe_name(i),
-			   pipe_crc_source_name(dev_priv->pipe_crc[i].source));
-
-	return 0;
-}
-
-static int display_crc_ctl_open(struct inode *inode, struct file *file)
-{
-	struct drm_device *dev = inode->i_private;
-
-	return single_open(file, display_crc_ctl_show, dev);
-}
-
-static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
-				 uint32_t *val)
-{
-	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
-		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
-
-	switch (*source) {
-	case INTEL_PIPE_CRC_SOURCE_PIPE:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_INCLUDE_BORDER_I8XX;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_NONE:
-		*val = 0;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int i9xx_pipe_crc_auto_source(struct drm_device *dev, enum pipe pipe,
-				     enum intel_pipe_crc_source *source)
-{
-	struct intel_encoder *encoder;
-	struct intel_crtc *crtc;
-	struct intel_digital_port *dig_port;
-	int ret = 0;
-
-	*source = INTEL_PIPE_CRC_SOURCE_PIPE;
-
-	mutex_lock(&dev->mode_config.mutex);
-	list_for_each_entry(encoder, &dev->mode_config.encoder_list,
-			    base.head) {
-		if (!encoder->base.crtc)
-			continue;
-
-		crtc = to_intel_crtc(encoder->base.crtc);
-
-		if (crtc->pipe != pipe)
-			continue;
-
-		switch (encoder->type) {
-		case INTEL_OUTPUT_TVOUT:
-			*source = INTEL_PIPE_CRC_SOURCE_TV;
-			break;
-		case INTEL_OUTPUT_DISPLAYPORT:
-		case INTEL_OUTPUT_EDP:
-			dig_port = enc_to_dig_port(&encoder->base);
-			switch (dig_port->port) {
-			case PORT_B:
-				*source = INTEL_PIPE_CRC_SOURCE_DP_B;
-				break;
-			case PORT_C:
-				*source = INTEL_PIPE_CRC_SOURCE_DP_C;
-				break;
-			case PORT_D:
-				*source = INTEL_PIPE_CRC_SOURCE_DP_D;
-				break;
-			default:
-				WARN(1, "nonexisting DP port %c\n",
-				     port_name(dig_port->port));
-				break;
-			}
-			break;
-		}
-	}
-	mutex_unlock(&dev->mode_config.mutex);
-
-	return ret;
-}
-
-static int vlv_pipe_crc_ctl_reg(struct drm_device *dev,
-				enum pipe pipe,
-				enum intel_pipe_crc_source *source,
-				uint32_t *val)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	bool need_stable_symbols = false;
-
-	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
-		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
-		if (ret)
-			return ret;
-	}
-
-	switch (*source) {
-	case INTEL_PIPE_CRC_SOURCE_PIPE:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_VLV;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_DP_B:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_B_VLV;
-		need_stable_symbols = true;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_DP_C:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_C_VLV;
-		need_stable_symbols = true;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_NONE:
-		*val = 0;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	/*
-	 * When the pipe CRC tap point is after the transcoders we need
-	 * to tweak symbol-level features to produce a deterministic series of
-	 * symbols for a given frame. We need to reset those features only once
-	 * a frame (instead of every nth symbol):
-	 *   - DC-balance: used to ensure a better clock recovery from the data
-	 *     link (SDVO)
-	 *   - DisplayPort scrambling: used for EMI reduction
-	 */
-	if (need_stable_symbols) {
-		uint32_t tmp = I915_READ(PORT_DFT2_G4X);
-
-		WARN_ON(!IS_G4X(dev));
-
-		tmp |= DC_BALANCE_RESET_VLV;
-		if (pipe == PIPE_A)
-			tmp |= PIPE_A_SCRAMBLE_RESET;
-		else
-			tmp |= PIPE_B_SCRAMBLE_RESET;
-
-		I915_WRITE(PORT_DFT2_G4X, tmp);
-	}
-
-	return 0;
-}
-
-static int i9xx_pipe_crc_ctl_reg(struct drm_device *dev,
-				 enum pipe pipe,
-				 enum intel_pipe_crc_source *source,
-				 uint32_t *val)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	bool need_stable_symbols = false;
-
-	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
-		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
-		if (ret)
-			return ret;
-	}
-
-	switch (*source) {
-	case INTEL_PIPE_CRC_SOURCE_PIPE:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_I9XX;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_TV:
-		if (!SUPPORTS_TV(dev))
-			return -EINVAL;
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_TV_PRE;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_DP_B:
-		if (!IS_G4X(dev))
-			return -EINVAL;
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_B_G4X;
-		need_stable_symbols = true;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_DP_C:
-		if (!IS_G4X(dev))
-			return -EINVAL;
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_C_G4X;
-		need_stable_symbols = true;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_DP_D:
-		if (!IS_G4X(dev))
-			return -EINVAL;
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_D_G4X;
-		need_stable_symbols = true;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_NONE:
-		*val = 0;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	/*
-	 * When the pipe CRC tap point is after the transcoders we need
-	 * to tweak symbol-level features to produce a deterministic series of
-	 * symbols for a given frame. We need to reset those features only once
-	 * a frame (instead of every nth symbol):
-	 *   - DC-balance: used to ensure a better clock recovery from the data
-	 *     link (SDVO)
-	 *   - DisplayPort scrambling: used for EMI reduction
-	 */
-	if (need_stable_symbols) {
-		uint32_t tmp = I915_READ(PORT_DFT2_G4X);
-
-		WARN_ON(!IS_G4X(dev));
-
-		I915_WRITE(PORT_DFT_I9XX,
-			   I915_READ(PORT_DFT_I9XX) | DC_BALANCE_RESET);
-
-		if (pipe == PIPE_A)
-			tmp |= PIPE_A_SCRAMBLE_RESET;
-		else
-			tmp |= PIPE_B_SCRAMBLE_RESET;
-
-		I915_WRITE(PORT_DFT2_G4X, tmp);
-	}
-
-	return 0;
-}
-
-static void vlv_undo_pipe_scramble_reset(struct drm_device *dev,
-					 enum pipe pipe)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	uint32_t tmp = I915_READ(PORT_DFT2_G4X);
-
-	if (pipe == PIPE_A)
-		tmp &= ~PIPE_A_SCRAMBLE_RESET;
-	else
-		tmp &= ~PIPE_B_SCRAMBLE_RESET;
-	if (!(tmp & PIPE_SCRAMBLE_RESET_MASK))
-		tmp &= ~DC_BALANCE_RESET_VLV;
-	I915_WRITE(PORT_DFT2_G4X, tmp);
-
-}
-
-static void g4x_undo_pipe_scramble_reset(struct drm_device *dev,
-					 enum pipe pipe)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	uint32_t tmp = I915_READ(PORT_DFT2_G4X);
-
-	if (pipe == PIPE_A)
-		tmp &= ~PIPE_A_SCRAMBLE_RESET;
-	else
-		tmp &= ~PIPE_B_SCRAMBLE_RESET;
-	I915_WRITE(PORT_DFT2_G4X, tmp);
-
-	if (!(tmp & PIPE_SCRAMBLE_RESET_MASK)) {
-		I915_WRITE(PORT_DFT_I9XX,
-			   I915_READ(PORT_DFT_I9XX) & ~DC_BALANCE_RESET);
-	}
-}
-
-static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
-				uint32_t *val)
-{
-	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
-		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
-
-	switch (*source) {
-	case INTEL_PIPE_CRC_SOURCE_PLANE1:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_ILK;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_PLANE2:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_ILK;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_PIPE:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_ILK;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_NONE:
-		*val = 0;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
-				uint32_t *val)
-{
-	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
-		*source = INTEL_PIPE_CRC_SOURCE_PF;
-
-	switch (*source) {
-	case INTEL_PIPE_CRC_SOURCE_PLANE1:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_IVB;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_PLANE2:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_PF:
-		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
-		break;
-	case INTEL_PIPE_CRC_SOURCE_NONE:
-		*val = 0;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
-			       enum intel_pipe_crc_source source)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
-	u32 val = 0; /* shut up gcc */
-	int ret;
-
-	if (pipe_crc->source == source)
-		return 0;
-
-	/* forbid changing the source without going back to 'none' */
-	if (pipe_crc->source && source)
-		return -EINVAL;
-
-	if (IS_GEN2(dev))
-		ret = i8xx_pipe_crc_ctl_reg(&source, &val);
-	else if (INTEL_INFO(dev)->gen < 5)
-		ret = i9xx_pipe_crc_ctl_reg(dev, pipe, &source, &val);
-	else if (IS_VALLEYVIEW(dev))
-		ret = vlv_pipe_crc_ctl_reg(dev,pipe, &source, &val);
-	else if (IS_GEN5(dev) || IS_GEN6(dev))
-		ret = ilk_pipe_crc_ctl_reg(&source, &val);
-	else
-		ret = ivb_pipe_crc_ctl_reg(&source, &val);
-
-	if (ret != 0)
-		return ret;
-
-	/* none -> real source transition */
-	if (source) {
-		DRM_DEBUG_DRIVER("collecting CRCs for pipe %c, %s\n",
-				 pipe_name(pipe), pipe_crc_source_name(source));
-
-		pipe_crc->entries = kzalloc(sizeof(*pipe_crc->entries) *
-					    INTEL_PIPE_CRC_ENTRIES_NR,
-					    GFP_KERNEL);
-		if (!pipe_crc->entries)
-			return -ENOMEM;
-
-		spin_lock_irq(&pipe_crc->lock);
-		pipe_crc->head = 0;
-		pipe_crc->tail = 0;
-		spin_unlock_irq(&pipe_crc->lock);
-	}
-
-	pipe_crc->source = source;
-
-	I915_WRITE(PIPE_CRC_CTL(pipe), val);
-	POSTING_READ(PIPE_CRC_CTL(pipe));
-
-	/* real source -> none transition */
-	if (source == INTEL_PIPE_CRC_SOURCE_NONE) {
-		struct intel_pipe_crc_entry *entries;
-
-		DRM_DEBUG_DRIVER("stopping CRCs for pipe %c\n",
-				 pipe_name(pipe));
-
-		intel_wait_for_vblank(dev, pipe);
-
-		spin_lock_irq(&pipe_crc->lock);
-		entries = pipe_crc->entries;
-		pipe_crc->entries = NULL;
-		spin_unlock_irq(&pipe_crc->lock);
-
-		kfree(entries);
-
-		if (IS_G4X(dev))
-			g4x_undo_pipe_scramble_reset(dev, pipe);
-		else if (IS_VALLEYVIEW(dev))
-			vlv_undo_pipe_scramble_reset(dev, pipe);
-	}
-
-	return 0;
-}
-
-/*
- * Parse pipe CRC command strings:
- *   command: wsp* object wsp+ name wsp+ source wsp*
- *   object: 'pipe'
- *   name: (A | B | C)
- *   source: (none | plane1 | plane2 | pf)
- *   wsp: (#0x20 | #0x9 | #0xA)+
- *
- * eg.:
- *  "pipe A plane1"  ->  Start CRC computations on plane1 of pipe A
- *  "pipe A none"    ->  Stop CRC
- */
-static int display_crc_ctl_tokenize(char *buf, char *words[], int max_words)
-{
-	int n_words = 0;
-
-	while (*buf) {
-		char *end;
-
-		/* skip leading white space */
-		buf = skip_spaces(buf);
-		if (!*buf)
-			break;	/* end of buffer */
-
-		/* find end of word */
-		for (end = buf; *end && !isspace(*end); end++)
-			;
-
-		if (n_words == max_words) {
-			DRM_DEBUG_DRIVER("too many words, allowed <= %d\n",
-					 max_words);
-			return -EINVAL;	/* ran out of words[] before bytes */
-		}
-
-		if (*end)
-			*end++ = '\0';
-		words[n_words++] = buf;
-		buf = end;
-	}
-
-	return n_words;
-}
-
-enum intel_pipe_crc_object {
-	PIPE_CRC_OBJECT_PIPE,
-};
-
-static const char * const pipe_crc_objects[] = {
-	"pipe",
-};
-
-static int
-display_crc_ctl_parse_object(const char *buf, enum intel_pipe_crc_object *o)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(pipe_crc_objects); i++)
-		if (!strcmp(buf, pipe_crc_objects[i])) {
-			*o = i;
-			return 0;
-		    }
-
-	return -EINVAL;
-}
-
-static int display_crc_ctl_parse_pipe(const char *buf, enum pipe *pipe)
-{
-	const char name = buf[0];
-
-	if (name < 'A' || name >= pipe_name(I915_MAX_PIPES))
-		return -EINVAL;
-
-	*pipe = name - 'A';
-
-	return 0;
-}
-
-static int
-display_crc_ctl_parse_source(const char *buf, enum intel_pipe_crc_source *s)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(pipe_crc_sources); i++)
-		if (!strcmp(buf, pipe_crc_sources[i])) {
-			*s = i;
-			return 0;
-		    }
-
-	return -EINVAL;
-}
-
-static int display_crc_ctl_parse(struct drm_device *dev, char *buf, size_t len)
-{
-#define N_WORDS 3
-	int n_words;
-	char *words[N_WORDS];
-	enum pipe pipe;
-	enum intel_pipe_crc_object object;
-	enum intel_pipe_crc_source source;
-
-	n_words = display_crc_ctl_tokenize(buf, words, N_WORDS);
-	if (n_words != N_WORDS) {
-		DRM_DEBUG_DRIVER("tokenize failed, a command is %d words\n",
-				 N_WORDS);
-		return -EINVAL;
-	}
-
-	if (display_crc_ctl_parse_object(words[0], &object) < 0) {
-		DRM_DEBUG_DRIVER("unknown object %s\n", words[0]);
-		return -EINVAL;
-	}
-
-	if (display_crc_ctl_parse_pipe(words[1], &pipe) < 0) {
-		DRM_DEBUG_DRIVER("unknown pipe %s\n", words[1]);
-		return -EINVAL;
-	}
-
-	if (display_crc_ctl_parse_source(words[2], &source) < 0) {
-		DRM_DEBUG_DRIVER("unknown source %s\n", words[2]);
-		return -EINVAL;
-	}
-
-	return pipe_crc_set_source(dev, pipe, source);
-}
-
-static ssize_t display_crc_ctl_write(struct file *file, const char __user *ubuf,
-				     size_t len, loff_t *offp)
-{
-	struct seq_file *m = file->private_data;
-	struct drm_device *dev = m->private;
-	char *tmpbuf;
-	int ret;
-
-	if (len == 0)
-		return 0;
-
-	if (len > PAGE_SIZE - 1) {
-		DRM_DEBUG_DRIVER("expected <%lu bytes into pipe crc control\n",
-				 PAGE_SIZE);
-		return -E2BIG;
-	}
-
-	tmpbuf = kmalloc(len + 1, GFP_KERNEL);
-	if (!tmpbuf)
-		return -ENOMEM;
-
-	if (copy_from_user(tmpbuf, ubuf, len)) {
-		ret = -EFAULT;
-		goto out;
-	}
-	tmpbuf[len] = '\0';
-
-	ret = display_crc_ctl_parse(dev, tmpbuf, len);
-
-out:
-	kfree(tmpbuf);
-	if (ret < 0)
-		return ret;
-
-	*offp += len;
-	return len;
-}
-
-static const struct file_operations i915_display_crc_ctl_fops = {
-	.owner = THIS_MODULE,
-	.open = display_crc_ctl_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-	.write = display_crc_ctl_write
-};
-
 static int
 i915_wedged_get(void *data, u64 *val)
 {
@@ -3268,20 +2492,6 @@ static const struct i915_debugfs_files {
 	{"i915_forcewake_user", &i915_forcewake_fops, S_IRUGO},
 };
 
-void intel_display_crc_init(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	enum pipe pipe;
-
-	for_each_pipe(pipe) {
-		struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
-
-		pipe_crc->opened = false;
-		spin_lock_init(&pipe_crc->lock);
-		init_waitqueue_head(&pipe_crc->wq);
-	}
-}
-
 int i915_debugfs_init(struct drm_minor *minor)
 {
 	int ret, i;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f888fea..3bdc34c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1356,6 +1356,18 @@ struct intel_pipe_crc {
 	wait_queue_head_t wq;
 };
 
+struct pipe_crc_info {
+	const char *name;
+	struct drm_device *dev;
+	enum pipe pipe;
+};
+
+extern struct pipe_crc_info i915_pipe_crc_data[I915_MAX_PIPES];
+extern const struct file_operations i915_display_crc_ctl_fops;
+
+int i915_pipe_crc_create(struct dentry *root, struct drm_minor *minor,
+			 enum pipe pipe);
+
 typedef struct drm_i915_private {
 	struct drm_device *dev;
 	struct kmem_cache *slab;
diff --git a/drivers/gpu/drm/i915/intel_display_test.c b/drivers/gpu/drm/i915/intel_display_test.c
new file mode 100644
index 0000000..12c4189
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_display_test.c
@@ -0,0 +1,801 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * 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.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/circ_buf.h>
+#include <linux/ctype.h>
+#include "i915_drv.h"
+#include "intel_drv.h"
+
+static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
+{
+	struct pipe_crc_info *info = inode->i_private;
+	struct drm_i915_private *dev_priv = info->dev->dev_private;
+	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
+
+	if (info->pipe >= INTEL_INFO(info->dev)->num_pipes)
+		return -ENODEV;
+
+	spin_lock_irq(&pipe_crc->lock);
+
+	if (pipe_crc->opened) {
+		spin_unlock_irq(&pipe_crc->lock);
+		return -EBUSY; /* already open */
+	}
+
+	pipe_crc->opened = true;
+	filep->private_data = inode->i_private;
+
+	spin_unlock_irq(&pipe_crc->lock);
+
+	return 0;
+}
+
+static int i915_pipe_crc_release(struct inode *inode, struct file *filep)
+{
+	struct pipe_crc_info *info = inode->i_private;
+	struct drm_i915_private *dev_priv = info->dev->dev_private;
+	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
+
+	spin_lock_irq(&pipe_crc->lock);
+	pipe_crc->opened = false;
+	spin_unlock_irq(&pipe_crc->lock);
+
+	return 0;
+}
+
+/* (6 fields, 8 chars each, space separated (5) + '\n') */
+#define PIPE_CRC_LINE_LEN	(6 * 8 + 5 + 1)
+/* account for \'0' */
+#define PIPE_CRC_BUFFER_LEN	(PIPE_CRC_LINE_LEN + 1)
+
+static int pipe_crc_data_count(struct intel_pipe_crc *pipe_crc)
+{
+	assert_spin_locked(&pipe_crc->lock);
+	return CIRC_CNT(pipe_crc->head, pipe_crc->tail,
+			INTEL_PIPE_CRC_ENTRIES_NR);
+}
+
+static ssize_t
+i915_pipe_crc_read(struct file *filep, char __user *user_buf, size_t count,
+		   loff_t *pos)
+{
+	struct pipe_crc_info *info = filep->private_data;
+	struct drm_device *dev = info->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
+	char buf[PIPE_CRC_BUFFER_LEN];
+	int head, tail, n_entries, n;
+	ssize_t bytes_read;
+
+	/*
+	 * Don't allow user space to provide buffers not big enough to hold
+	 * a line of data.
+	 */
+	if (count < PIPE_CRC_LINE_LEN)
+		return -EINVAL;
+
+	if (pipe_crc->source == INTEL_PIPE_CRC_SOURCE_NONE)
+		return 0;
+
+	/* nothing to read */
+	spin_lock_irq(&pipe_crc->lock);
+	while (pipe_crc_data_count(pipe_crc) == 0) {
+		int ret;
+
+		if (filep->f_flags & O_NONBLOCK) {
+			spin_unlock_irq(&pipe_crc->lock);
+			return -EAGAIN;
+		}
+
+		ret = wait_event_interruptible_lock_irq(pipe_crc->wq,
+				pipe_crc_data_count(pipe_crc), pipe_crc->lock);
+		if (ret) {
+			spin_unlock_irq(&pipe_crc->lock);
+			return ret;
+		}
+	}
+
+	/* We now have one or more entries to read */
+	head = pipe_crc->head;
+	tail = pipe_crc->tail;
+	n_entries = min((size_t)CIRC_CNT(head, tail, INTEL_PIPE_CRC_ENTRIES_NR),
+			count / PIPE_CRC_LINE_LEN);
+	spin_unlock_irq(&pipe_crc->lock);
+
+	bytes_read = 0;
+	n = 0;
+	do {
+		struct intel_pipe_crc_entry *entry = &pipe_crc->entries[tail];
+		int ret;
+
+		bytes_read += snprintf(buf, PIPE_CRC_BUFFER_LEN,
+				       "%8u %8x %8x %8x %8x %8x\n",
+				       entry->frame, entry->crc[0],
+				       entry->crc[1], entry->crc[2],
+				       entry->crc[3], entry->crc[4]);
+
+		ret = copy_to_user(user_buf + n * PIPE_CRC_LINE_LEN,
+				   buf, PIPE_CRC_LINE_LEN);
+		if (ret == PIPE_CRC_LINE_LEN)
+			return -EFAULT;
+
+		BUILD_BUG_ON_NOT_POWER_OF_2(INTEL_PIPE_CRC_ENTRIES_NR);
+		tail = (tail + 1) & (INTEL_PIPE_CRC_ENTRIES_NR - 1);
+		n++;
+	} while (--n_entries);
+
+	spin_lock_irq(&pipe_crc->lock);
+	pipe_crc->tail = tail;
+	spin_unlock_irq(&pipe_crc->lock);
+
+	return bytes_read;
+}
+
+const struct file_operations i915_pipe_crc_fops = {
+	.owner = THIS_MODULE,
+	.open = i915_pipe_crc_open,
+	.read = i915_pipe_crc_read,
+	.release = i915_pipe_crc_release,
+};
+
+struct pipe_crc_info i915_pipe_crc_data[I915_MAX_PIPES] = {
+	{
+		.name = "i915_pipe_A_crc",
+		.pipe = PIPE_A,
+	},
+	{
+		.name = "i915_pipe_B_crc",
+		.pipe = PIPE_B,
+	},
+	{
+		.name = "i915_pipe_C_crc",
+		.pipe = PIPE_C,
+	},
+};
+
+int i915_pipe_crc_create(struct dentry *root, struct drm_minor *minor,
+			 enum pipe pipe)
+{
+	struct drm_device *dev = minor->dev;
+	struct dentry *ent;
+	struct pipe_crc_info *info = &i915_pipe_crc_data[pipe];
+	struct drm_info_node *node;
+
+	info->dev = dev;
+	ent = debugfs_create_file(info->name, S_IRUGO, root, info,
+				  &i915_pipe_crc_fops);
+	if (!ent)
+		return -ENOMEM;
+
+	node = kmalloc(sizeof(*node), GFP_KERNEL);
+	if (node == NULL) {
+		debugfs_remove(ent);
+		return -ENOMEM;
+	}
+
+	node->minor = minor;
+	node->dent = ent;
+	node->info_ent = (void *)info;
+
+	mutex_lock(&minor->debugfs_lock);
+	list_add(&node->list, &minor->debugfs_list);
+	mutex_unlock(&minor->debugfs_lock);
+
+	return 0;
+}
+
+static const char * const pipe_crc_sources[] = {
+	"none",
+	"plane1",
+	"plane2",
+	"pf",
+	"pipe",
+	"TV",
+	"DP-B",
+	"DP-C",
+	"DP-D",
+	"auto",
+};
+
+static const char *pipe_crc_source_name(enum intel_pipe_crc_source source)
+{
+	BUILD_BUG_ON(ARRAY_SIZE(pipe_crc_sources) != INTEL_PIPE_CRC_SOURCE_MAX);
+	return pipe_crc_sources[source];
+}
+
+static int display_crc_ctl_show(struct seq_file *m, void *data)
+{
+	struct drm_device *dev = m->private;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	for (i = 0; i < I915_MAX_PIPES; i++)
+		seq_printf(m, "%c %s\n", pipe_name(i),
+			   pipe_crc_source_name(dev_priv->pipe_crc[i].source));
+
+	return 0;
+}
+
+static int display_crc_ctl_open(struct inode *inode, struct file *file)
+{
+	struct drm_device *dev = inode->i_private;
+
+	return single_open(file, display_crc_ctl_show, dev);
+}
+
+static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
+				 uint32_t *val)
+{
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	switch (*source) {
+	case INTEL_PIPE_CRC_SOURCE_PIPE:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_INCLUDE_BORDER_I8XX;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_NONE:
+		*val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int i9xx_pipe_crc_auto_source(struct drm_device *dev, enum pipe pipe,
+				     enum intel_pipe_crc_source *source)
+{
+	struct intel_encoder *encoder;
+	struct intel_crtc *crtc;
+	struct intel_digital_port *dig_port;
+	int ret = 0;
+
+	*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	mutex_lock(&dev->mode_config.mutex);
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list,
+			    base.head) {
+		if (!encoder->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(encoder->base.crtc);
+
+		if (crtc->pipe != pipe)
+			continue;
+
+		switch (encoder->type) {
+		case INTEL_OUTPUT_TVOUT:
+			*source = INTEL_PIPE_CRC_SOURCE_TV;
+			break;
+		case INTEL_OUTPUT_DISPLAYPORT:
+		case INTEL_OUTPUT_EDP:
+			dig_port = enc_to_dig_port(&encoder->base);
+			switch (dig_port->port) {
+			case PORT_B:
+				*source = INTEL_PIPE_CRC_SOURCE_DP_B;
+				break;
+			case PORT_C:
+				*source = INTEL_PIPE_CRC_SOURCE_DP_C;
+				break;
+			case PORT_D:
+				*source = INTEL_PIPE_CRC_SOURCE_DP_D;
+				break;
+			default:
+				WARN(1, "nonexisting DP port %c\n",
+				     port_name(dig_port->port));
+				break;
+			}
+			break;
+		}
+	}
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return ret;
+}
+
+static int vlv_pipe_crc_ctl_reg(struct drm_device *dev,
+				enum pipe pipe,
+				enum intel_pipe_crc_source *source,
+				uint32_t *val)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	bool need_stable_symbols = false;
+
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
+		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
+		if (ret)
+			return ret;
+	}
+
+	switch (*source) {
+	case INTEL_PIPE_CRC_SOURCE_PIPE:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_VLV;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_DP_B:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_B_VLV;
+		need_stable_symbols = true;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_DP_C:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_C_VLV;
+		need_stable_symbols = true;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_NONE:
+		*val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * When the pipe CRC tap point is after the transcoders we need
+	 * to tweak symbol-level features to produce a deterministic series of
+	 * symbols for a given frame. We need to reset those features only once
+	 * a frame (instead of every nth symbol):
+	 *   - DC-balance: used to ensure a better clock recovery from the data
+	 *     link (SDVO)
+	 *   - DisplayPort scrambling: used for EMI reduction
+	 */
+	if (need_stable_symbols) {
+		uint32_t tmp = I915_READ(PORT_DFT2_G4X);
+
+		WARN_ON(!IS_G4X(dev));
+
+		tmp |= DC_BALANCE_RESET_VLV;
+		if (pipe == PIPE_A)
+			tmp |= PIPE_A_SCRAMBLE_RESET;
+		else
+			tmp |= PIPE_B_SCRAMBLE_RESET;
+
+		I915_WRITE(PORT_DFT2_G4X, tmp);
+	}
+
+	return 0;
+}
+
+static int i9xx_pipe_crc_ctl_reg(struct drm_device *dev,
+				 enum pipe pipe,
+				 enum intel_pipe_crc_source *source,
+				 uint32_t *val)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	bool need_stable_symbols = false;
+
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
+		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
+		if (ret)
+			return ret;
+	}
+
+	switch (*source) {
+	case INTEL_PIPE_CRC_SOURCE_PIPE:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_I9XX;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_TV:
+		if (!SUPPORTS_TV(dev))
+			return -EINVAL;
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_TV_PRE;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_DP_B:
+		if (!IS_G4X(dev))
+			return -EINVAL;
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_B_G4X;
+		need_stable_symbols = true;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_DP_C:
+		if (!IS_G4X(dev))
+			return -EINVAL;
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_C_G4X;
+		need_stable_symbols = true;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_DP_D:
+		if (!IS_G4X(dev))
+			return -EINVAL;
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_DP_D_G4X;
+		need_stable_symbols = true;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_NONE:
+		*val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * When the pipe CRC tap point is after the transcoders we need
+	 * to tweak symbol-level features to produce a deterministic series of
+	 * symbols for a given frame. We need to reset those features only once
+	 * a frame (instead of every nth symbol):
+	 *   - DC-balance: used to ensure a better clock recovery from the data
+	 *     link (SDVO)
+	 *   - DisplayPort scrambling: used for EMI reduction
+	 */
+	if (need_stable_symbols) {
+		uint32_t tmp = I915_READ(PORT_DFT2_G4X);
+
+		WARN_ON(!IS_G4X(dev));
+
+		I915_WRITE(PORT_DFT_I9XX,
+			   I915_READ(PORT_DFT_I9XX) | DC_BALANCE_RESET);
+
+		if (pipe == PIPE_A)
+			tmp |= PIPE_A_SCRAMBLE_RESET;
+		else
+			tmp |= PIPE_B_SCRAMBLE_RESET;
+
+		I915_WRITE(PORT_DFT2_G4X, tmp);
+	}
+
+	return 0;
+}
+
+static void vlv_undo_pipe_scramble_reset(struct drm_device *dev,
+					 enum pipe pipe)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t tmp = I915_READ(PORT_DFT2_G4X);
+
+	if (pipe == PIPE_A)
+		tmp &= ~PIPE_A_SCRAMBLE_RESET;
+	else
+		tmp &= ~PIPE_B_SCRAMBLE_RESET;
+	if (!(tmp & PIPE_SCRAMBLE_RESET_MASK))
+		tmp &= ~DC_BALANCE_RESET_VLV;
+	I915_WRITE(PORT_DFT2_G4X, tmp);
+
+}
+
+static void g4x_undo_pipe_scramble_reset(struct drm_device *dev,
+					 enum pipe pipe)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t tmp = I915_READ(PORT_DFT2_G4X);
+
+	if (pipe == PIPE_A)
+		tmp &= ~PIPE_A_SCRAMBLE_RESET;
+	else
+		tmp &= ~PIPE_B_SCRAMBLE_RESET;
+	I915_WRITE(PORT_DFT2_G4X, tmp);
+
+	if (!(tmp & PIPE_SCRAMBLE_RESET_MASK)) {
+		I915_WRITE(PORT_DFT_I9XX,
+			   I915_READ(PORT_DFT_I9XX) & ~DC_BALANCE_RESET);
+	}
+}
+
+static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
+				uint32_t *val)
+{
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	switch (*source) {
+	case INTEL_PIPE_CRC_SOURCE_PLANE1:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_ILK;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_PLANE2:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_ILK;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_PIPE:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_ILK;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_NONE:
+		*val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
+				uint32_t *val)
+{
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PF;
+
+	switch (*source) {
+	case INTEL_PIPE_CRC_SOURCE_PLANE1:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_IVB;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_PLANE2:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_PF:
+		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
+		break;
+	case INTEL_PIPE_CRC_SOURCE_NONE:
+		*val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
+			       enum intel_pipe_crc_source source)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
+	u32 val = 0; /* shut up gcc */
+	int ret;
+
+	if (pipe_crc->source == source)
+		return 0;
+
+	/* forbid changing the source without going back to 'none' */
+	if (pipe_crc->source && source)
+		return -EINVAL;
+
+	if (IS_GEN2(dev))
+		ret = i8xx_pipe_crc_ctl_reg(&source, &val);
+	else if (INTEL_INFO(dev)->gen < 5)
+		ret = i9xx_pipe_crc_ctl_reg(dev, pipe, &source, &val);
+	else if (IS_VALLEYVIEW(dev))
+		ret = vlv_pipe_crc_ctl_reg(dev,pipe, &source, &val);
+	else if (IS_GEN5(dev) || IS_GEN6(dev))
+		ret = ilk_pipe_crc_ctl_reg(&source, &val);
+	else
+		ret = ivb_pipe_crc_ctl_reg(&source, &val);
+
+	if (ret != 0)
+		return ret;
+
+	/* none -> real source transition */
+	if (source) {
+		DRM_DEBUG_DRIVER("collecting CRCs for pipe %c, %s\n",
+				 pipe_name(pipe), pipe_crc_source_name(source));
+
+		pipe_crc->entries = kzalloc(sizeof(*pipe_crc->entries) *
+					    INTEL_PIPE_CRC_ENTRIES_NR,
+					    GFP_KERNEL);
+		if (!pipe_crc->entries)
+			return -ENOMEM;
+
+		spin_lock_irq(&pipe_crc->lock);
+		pipe_crc->head = 0;
+		pipe_crc->tail = 0;
+		spin_unlock_irq(&pipe_crc->lock);
+	}
+
+	pipe_crc->source = source;
+
+	I915_WRITE(PIPE_CRC_CTL(pipe), val);
+	POSTING_READ(PIPE_CRC_CTL(pipe));
+
+	/* real source -> none transition */
+	if (source == INTEL_PIPE_CRC_SOURCE_NONE) {
+		struct intel_pipe_crc_entry *entries;
+
+		DRM_DEBUG_DRIVER("stopping CRCs for pipe %c\n",
+				 pipe_name(pipe));
+
+		intel_wait_for_vblank(dev, pipe);
+
+		spin_lock_irq(&pipe_crc->lock);
+		entries = pipe_crc->entries;
+		pipe_crc->entries = NULL;
+		spin_unlock_irq(&pipe_crc->lock);
+
+		kfree(entries);
+
+		if (IS_G4X(dev))
+			g4x_undo_pipe_scramble_reset(dev, pipe);
+		else if (IS_VALLEYVIEW(dev))
+			vlv_undo_pipe_scramble_reset(dev, pipe);
+	}
+
+	return 0;
+}
+
+/*
+ * Parse pipe CRC command strings:
+ *   command: wsp* object wsp+ name wsp+ source wsp*
+ *   object: 'pipe'
+ *   name: (A | B | C)
+ *   source: (none | plane1 | plane2 | pf)
+ *   wsp: (#0x20 | #0x9 | #0xA)+
+ *
+ * eg.:
+ *  "pipe A plane1"  ->  Start CRC computations on plane1 of pipe A
+ *  "pipe A none"    ->  Stop CRC
+ */
+static int display_crc_ctl_tokenize(char *buf, char *words[], int max_words)
+{
+	int n_words = 0;
+
+	while (*buf) {
+		char *end;
+
+		/* skip leading white space */
+		buf = skip_spaces(buf);
+		if (!*buf)
+			break;	/* end of buffer */
+
+		/* find end of word */
+		for (end = buf; *end && !isspace(*end); end++)
+			;
+
+		if (n_words == max_words) {
+			DRM_DEBUG_DRIVER("too many words, allowed <= %d\n",
+					 max_words);
+			return -EINVAL;	/* ran out of words[] before bytes */
+		}
+
+		if (*end)
+			*end++ = '\0';
+		words[n_words++] = buf;
+		buf = end;
+	}
+
+	return n_words;
+}
+
+enum intel_pipe_crc_object {
+	PIPE_CRC_OBJECT_PIPE,
+};
+
+static const char * const pipe_crc_objects[] = {
+	"pipe",
+};
+
+static int
+display_crc_ctl_parse_object(const char *buf, enum intel_pipe_crc_object *o)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pipe_crc_objects); i++)
+		if (!strcmp(buf, pipe_crc_objects[i])) {
+			*o = i;
+			return 0;
+		    }
+
+	return -EINVAL;
+}
+
+static int display_crc_ctl_parse_pipe(const char *buf, enum pipe *pipe)
+{
+	const char name = buf[0];
+
+	if (name < 'A' || name >= pipe_name(I915_MAX_PIPES))
+		return -EINVAL;
+
+	*pipe = name - 'A';
+
+	return 0;
+}
+
+static int
+display_crc_ctl_parse_source(const char *buf, enum intel_pipe_crc_source *s)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pipe_crc_sources); i++)
+		if (!strcmp(buf, pipe_crc_sources[i])) {
+			*s = i;
+			return 0;
+		    }
+
+	return -EINVAL;
+}
+
+static int display_crc_ctl_parse(struct drm_device *dev, char *buf, size_t len)
+{
+#define N_WORDS 3
+	int n_words;
+	char *words[N_WORDS];
+	enum pipe pipe;
+	enum intel_pipe_crc_object object;
+	enum intel_pipe_crc_source source;
+
+	n_words = display_crc_ctl_tokenize(buf, words, N_WORDS);
+	if (n_words != N_WORDS) {
+		DRM_DEBUG_DRIVER("tokenize failed, a command is %d words\n",
+				 N_WORDS);
+		return -EINVAL;
+	}
+
+	if (display_crc_ctl_parse_object(words[0], &object) < 0) {
+		DRM_DEBUG_DRIVER("unknown object %s\n", words[0]);
+		return -EINVAL;
+	}
+
+	if (display_crc_ctl_parse_pipe(words[1], &pipe) < 0) {
+		DRM_DEBUG_DRIVER("unknown pipe %s\n", words[1]);
+		return -EINVAL;
+	}
+
+	if (display_crc_ctl_parse_source(words[2], &source) < 0) {
+		DRM_DEBUG_DRIVER("unknown source %s\n", words[2]);
+		return -EINVAL;
+	}
+
+	return pipe_crc_set_source(dev, pipe, source);
+}
+
+static ssize_t display_crc_ctl_write(struct file *file, const char __user *ubuf,
+				     size_t len, loff_t *offp)
+{
+	struct seq_file *m = file->private_data;
+	struct drm_device *dev = m->private;
+	char *tmpbuf;
+	int ret;
+
+	if (len == 0)
+		return 0;
+
+	if (len > PAGE_SIZE - 1) {
+		DRM_DEBUG_DRIVER("expected <%lu bytes into pipe crc control\n",
+				 PAGE_SIZE);
+		return -E2BIG;
+	}
+
+	tmpbuf = kmalloc(len + 1, GFP_KERNEL);
+	if (!tmpbuf)
+		return -ENOMEM;
+
+	if (copy_from_user(tmpbuf, ubuf, len)) {
+		ret = -EFAULT;
+		goto out;
+	}
+	tmpbuf[len] = '\0';
+
+	ret = display_crc_ctl_parse(dev, tmpbuf, len);
+
+out:
+	kfree(tmpbuf);
+	if (ret < 0)
+		return ret;
+
+	*offp += len;
+	return len;
+}
+
+void intel_display_crc_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum pipe pipe;
+
+	for_each_pipe(pipe) {
+		struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
+
+		pipe_crc->opened = false;
+		spin_lock_init(&pipe_crc->lock);
+		init_waitqueue_head(&pipe_crc->wq);
+	}
+}
+
+const struct file_operations i915_display_crc_ctl_fops = {
+	.owner = THIS_MODULE,
+	.open = display_crc_ctl_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.write = display_crc_ctl_write
+};
-- 
1.8.5.3




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