drm/i915: Add HDCP framework + base implementation

This patch adds the framework required to add HDCP support to intel
connectors. It implements Aksv loading from fuse, and parts 1/2/3
of the HDCP authentication scheme.

Note that without shim implementations, this does not actually implement
HDCP. That will come in subsequent patches.

Changes in v2:
- Don't open code wait_fors (Chris)
- drm_hdcp.c under MIT license (Daniel)
- Move intel_hdcp_disable() call above ddi_disable (Ram)
- Fix // comments (I wore a cone of shame for 12 hours to atone) (Daniel)
- Justify intel_hdcp_shim with comments (Daniel)
- Fixed async locking issues by adding hdcp_mutex (Daniel)
- Don't alter connector_state in enable/disable (Daniel)
Changes in v3:
- Added hdcp_mutex/hdcp_value to make async reasonable
- Added hdcp_prop_work to separate link checking & property setting
- Added new helper for atomic_check state tracking (Daniel)
- Moved enable/disable into atomic_commit with matching helpers
- Moved intel_hdcp_check_link out of all locks when called from dp
- Bumped up ksv_fifo timeout (noticed failure on one of my dongles)
Changes in v4:
- Remove SKL_ prefix from most register names (Daniel)
- Move enable/disable back to modeset path (Daniel)
- s/get_random_long/get_random_u32/ (Daniel)
- Remove mode_config.mutex lock in prop_work (Daniel)
- Add intel_hdcp_init to handle init of conn components (Daniel)
- Actually check return value of attach_property
- Check Bksv is valid before trying to authenticate (Ram)
Changes in v5:
- checkpatch whitespace changes
- s/DRM_MODE_CONTENT_PROTECTION_OFF/DRM_MODE_CONTENT_PROTECTION_UNDESIRED/
- Fix ksv list wait timeout (actually wait 5s)
- Increase the R0 timeout to 300ms (Ram)
Changes in v6:
- SPDX license

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ramalingam C <ramalingm.c@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180108195545.218615-6-seanpaul@chromium.org
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
new file mode 100644
index 0000000..3c164a2
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -0,0 +1,723 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * Authors:
+ * Sean Paul <seanpaul@chromium.org>
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_hdcp.h>
+#include <linux/i2c.h>
+#include <linux/random.h>
+
+#include "intel_drv.h"
+#include "i915_reg.h"
+
+#define KEY_LOAD_TRIES	5
+
+static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
+				    const struct intel_hdcp_shim *shim)
+{
+	int ret, read_ret;
+	bool ksv_ready;
+
+	/* Poll for ksv list ready (spec says max time allowed is 5s) */
+	ret = __wait_for(read_ret = shim->read_ksv_ready(intel_dig_port,
+							 &ksv_ready),
+			 read_ret || ksv_ready, 5 * 1000 * 1000, 1000,
+			 100 * 1000);
+	if (ret)
+		return ret;
+	if (read_ret)
+		return read_ret;
+	if (!ksv_ready)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static void intel_hdcp_clear_keys(struct drm_i915_private *dev_priv)
+{
+	I915_WRITE(HDCP_KEY_CONF, HDCP_CLEAR_KEYS_TRIGGER);
+	I915_WRITE(HDCP_KEY_STATUS, HDCP_KEY_LOAD_DONE | HDCP_KEY_LOAD_STATUS |
+		   HDCP_FUSE_IN_PROGRESS | HDCP_FUSE_ERROR | HDCP_FUSE_DONE);
+}
+
+static int intel_hdcp_load_keys(struct drm_i915_private *dev_priv)
+{
+	int ret;
+	u32 val;
+
+	/* Initiate loading the HDCP key from fuses */
+	mutex_lock(&dev_priv->pcu_lock);
+	ret = sandybridge_pcode_write(dev_priv, SKL_PCODE_LOAD_HDCP_KEYS, 1);
+	mutex_unlock(&dev_priv->pcu_lock);
+	if (ret) {
+		DRM_ERROR("Failed to initiate HDCP key load (%d)\n", ret);
+		return ret;
+	}
+
+	/* Wait for the keys to load (500us) */
+	ret = __intel_wait_for_register(dev_priv, HDCP_KEY_STATUS,
+					HDCP_KEY_LOAD_DONE, HDCP_KEY_LOAD_DONE,
+					10, 1, &val);
+	if (ret)
+		return ret;
+	else if (!(val & HDCP_KEY_LOAD_STATUS))
+		return -ENXIO;
+
+	/* Send Aksv over to PCH display for use in authentication */
+	I915_WRITE(HDCP_KEY_CONF, HDCP_AKSV_SEND_TRIGGER);
+
+	return 0;
+}
+
+/* Returns updated SHA-1 index */
+static int intel_write_sha_text(struct drm_i915_private *dev_priv, u32 sha_text)
+{
+	I915_WRITE(HDCP_SHA_TEXT, sha_text);
+	if (intel_wait_for_register(dev_priv, HDCP_REP_CTL,
+				    HDCP_SHA1_READY, HDCP_SHA1_READY, 1)) {
+		DRM_ERROR("Timed out waiting for SHA1 ready\n");
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+static
+u32 intel_hdcp_get_repeater_ctl(struct intel_digital_port *intel_dig_port)
+{
+	enum port port = intel_dig_port->base.port;
+	switch (port) {
+	case PORT_A:
+		return HDCP_DDIA_REP_PRESENT | HDCP_DDIA_SHA1_M0;
+	case PORT_B:
+		return HDCP_DDIB_REP_PRESENT | HDCP_DDIB_SHA1_M0;
+	case PORT_C:
+		return HDCP_DDIC_REP_PRESENT | HDCP_DDIC_SHA1_M0;
+	case PORT_D:
+		return HDCP_DDID_REP_PRESENT | HDCP_DDID_SHA1_M0;
+	case PORT_E:
+		return HDCP_DDIE_REP_PRESENT | HDCP_DDIE_SHA1_M0;
+	default:
+		break;
+	}
+	DRM_ERROR("Unknown port %d\n", port);
+	return -EINVAL;
+}
+
+static
+bool intel_hdcp_is_ksv_valid(u8 *ksv)
+{
+	int i, ones = 0;
+	/* KSV has 20 1's and 20 0's */
+	for (i = 0; i < DRM_HDCP_KSV_LEN; i++)
+		ones += hweight8(ksv[i]);
+	if (ones != 20)
+		return false;
+	return true;
+}
+
+/* Implements Part 2 of the HDCP authorization procedure */
+static
+int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
+			       const struct intel_hdcp_shim *shim)
+{
+	struct drm_i915_private *dev_priv;
+	u32 vprime, sha_text, sha_leftovers, rep_ctl;
+	u8 bstatus[2], num_downstream, *ksv_fifo;
+	int ret, i, j, sha_idx;
+
+	dev_priv = intel_dig_port->base.base.dev->dev_private;
+
+	ret = shim->read_bstatus(intel_dig_port, bstatus);
+	if (ret)
+		return ret;
+
+	/* If there are no downstream devices, we're all done. */
+	num_downstream = DRM_HDCP_NUM_DOWNSTREAM(bstatus[0]);
+	if (num_downstream == 0) {
+		DRM_INFO("HDCP is enabled (no downstream devices)\n");
+		return 0;
+	}
+
+	ret = intel_hdcp_poll_ksv_fifo(intel_dig_port, shim);
+	if (ret) {
+		DRM_ERROR("KSV list failed to become ready (%d)\n", ret);
+		return ret;
+	}
+
+	ksv_fifo = kzalloc(num_downstream * DRM_HDCP_KSV_LEN, GFP_KERNEL);
+	if (!ksv_fifo)
+		return -ENOMEM;
+
+	ret = shim->read_ksv_fifo(intel_dig_port, num_downstream, ksv_fifo);
+	if (ret)
+		return ret;
+
+	/* Process V' values from the receiver */
+	for (i = 0; i < DRM_HDCP_V_PRIME_NUM_PARTS; i++) {
+		ret = shim->read_v_prime_part(intel_dig_port, i, &vprime);
+		if (ret)
+			return ret;
+		I915_WRITE(HDCP_SHA_V_PRIME(i), vprime);
+	}
+
+	/*
+	 * We need to write the concatenation of all device KSVs, BINFO (DP) ||
+	 * BSTATUS (HDMI), and M0 (which is added via HDCP_REP_CTL). This byte
+	 * stream is written via the HDCP_SHA_TEXT register in 32-bit
+	 * increments. Every 64 bytes, we need to write HDCP_REP_CTL again. This
+	 * index will keep track of our progress through the 64 bytes as well as
+	 * helping us work the 40-bit KSVs through our 32-bit register.
+	 *
+	 * NOTE: data passed via HDCP_SHA_TEXT should be big-endian
+	 */
+	sha_idx = 0;
+	sha_text = 0;
+	sha_leftovers = 0;
+	rep_ctl = intel_hdcp_get_repeater_ctl(intel_dig_port);
+	I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+	for (i = 0; i < num_downstream; i++) {
+		unsigned int sha_empty;
+		u8 *ksv = &ksv_fifo[i * DRM_HDCP_KSV_LEN];
+
+		/* Fill up the empty slots in sha_text and write it out */
+		sha_empty = sizeof(sha_text) - sha_leftovers;
+		for (j = 0; j < sha_empty; j++)
+			sha_text |= ksv[j] << ((sizeof(sha_text) - j - 1) * 8);
+
+		ret = intel_write_sha_text(dev_priv, sha_text);
+		if (ret < 0)
+			return ret;
+
+		/* Programming guide writes this every 64 bytes */
+		sha_idx += sizeof(sha_text);
+		if (!(sha_idx % 64))
+			I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+
+		/* Store the leftover bytes from the ksv in sha_text */
+		sha_leftovers = DRM_HDCP_KSV_LEN - sha_empty;
+		sha_text = 0;
+		for (j = 0; j < sha_leftovers; j++)
+			sha_text |= ksv[sha_empty + j] <<
+					((sizeof(sha_text) - j - 1) * 8);
+
+		/*
+		 * If we still have room in sha_text for more data, continue.
+		 * Otherwise, write it out immediately.
+		 */
+		if (sizeof(sha_text) > sha_leftovers)
+			continue;
+
+		ret = intel_write_sha_text(dev_priv, sha_text);
+		if (ret < 0)
+			return ret;
+		sha_leftovers = 0;
+		sha_text = 0;
+		sha_idx += sizeof(sha_text);
+	}
+
+	/*
+	 * We need to write BINFO/BSTATUS, and M0 now. Depending on how many
+	 * bytes are leftover from the last ksv, we might be able to fit them
+	 * all in sha_text (first 2 cases), or we might need to split them up
+	 * into 2 writes (last 2 cases).
+	 */
+	if (sha_leftovers == 0) {
+		/* Write 16 bits of text, 16 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_16);
+		ret = intel_write_sha_text(dev_priv,
+					   bstatus[0] << 8 | bstatus[1]);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 32 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 16 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_16);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+	} else if (sha_leftovers == 1) {
+		/* Write 24 bits of text, 8 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_24);
+		sha_text |= bstatus[0] << 16 | bstatus[1] << 8;
+		/* Only 24-bits of data, must be in the LSB */
+		sha_text = (sha_text & 0xffffff00) >> 8;
+		ret = intel_write_sha_text(dev_priv, sha_text);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 32 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 24 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_8);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+	} else if (sha_leftovers == 2) {
+		/* Write 32 bits of text */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+		sha_text |= bstatus[0] << 24 | bstatus[1] << 16;
+		ret = intel_write_sha_text(dev_priv, sha_text);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 64 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+		for (i = 0; i < 2; i++) {
+			ret = intel_write_sha_text(dev_priv, 0);
+			if (ret < 0)
+				return ret;
+			sha_idx += sizeof(sha_text);
+		}
+	} else if (sha_leftovers == 3) {
+		/* Write 32 bits of text */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+		sha_text |= bstatus[0] << 24;
+		ret = intel_write_sha_text(dev_priv, sha_text);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 8 bits of text, 24 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_8);
+		ret = intel_write_sha_text(dev_priv, bstatus[1]);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 32 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_0);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+
+		/* Write 8 bits of M0 */
+		I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_24);
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+	} else {
+		DRM_ERROR("Invalid number of leftovers %d\n", sha_leftovers);
+		return -EINVAL;
+	}
+
+	I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_TEXT_32);
+	/* Fill up to 64-4 bytes with zeros (leave the last write for length) */
+	while ((sha_idx % 64) < (64 - sizeof(sha_text))) {
+		ret = intel_write_sha_text(dev_priv, 0);
+		if (ret < 0)
+			return ret;
+		sha_idx += sizeof(sha_text);
+	}
+
+	/*
+	 * Last write gets the length of the concatenation in bits. That is:
+	 *  - 5 bytes per device
+	 *  - 10 bytes for BINFO/BSTATUS(2), M0(8)
+	 */
+	sha_text = (num_downstream * 5 + 10) * 8;
+	ret = intel_write_sha_text(dev_priv, sha_text);
+	if (ret < 0)
+		return ret;
+
+	/* Tell the HW we're done with the hash and wait for it to ACK */
+	I915_WRITE(HDCP_REP_CTL, rep_ctl | HDCP_SHA1_COMPLETE_HASH);
+	if (intel_wait_for_register(dev_priv, HDCP_REP_CTL,
+				    HDCP_SHA1_COMPLETE,
+				    HDCP_SHA1_COMPLETE, 1)) {
+		DRM_ERROR("Timed out waiting for SHA1 complete\n");
+		return -ETIMEDOUT;
+	}
+	if (!(I915_READ(HDCP_REP_CTL) & HDCP_SHA1_V_MATCH)) {
+		DRM_ERROR("SHA-1 mismatch, HDCP failed\n");
+		return -ENXIO;
+	}
+
+	DRM_INFO("HDCP is enabled (%d downstream devices)\n", num_downstream);
+	return 0;
+}
+
+/* Implements Part 1 of the HDCP authorization procedure */
+static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port,
+			   const struct intel_hdcp_shim *shim)
+{
+	struct drm_i915_private *dev_priv;
+	enum port port;
+	unsigned long r0_prime_gen_start;
+	int ret, i;
+	union {
+		u32 reg[2];
+		u8 shim[DRM_HDCP_AN_LEN];
+	} an;
+	union {
+		u32 reg[2];
+		u8 shim[DRM_HDCP_KSV_LEN];
+	} bksv;
+	union {
+		u32 reg;
+		u8 shim[DRM_HDCP_RI_LEN];
+	} ri;
+	bool repeater_present;
+
+	dev_priv = intel_dig_port->base.base.dev->dev_private;
+
+	port = intel_dig_port->base.port;
+
+	/* Initialize An with 2 random values and acquire it */
+	for (i = 0; i < 2; i++)
+		I915_WRITE(PORT_HDCP_ANINIT(port), get_random_u32());
+	I915_WRITE(PORT_HDCP_CONF(port), HDCP_CONF_CAPTURE_AN);
+
+	/* Wait for An to be acquired */
+	if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port),
+				    HDCP_STATUS_AN_READY,
+				    HDCP_STATUS_AN_READY, 1)) {
+		DRM_ERROR("Timed out waiting for An\n");
+		return -ETIMEDOUT;
+	}
+
+	an.reg[0] = I915_READ(PORT_HDCP_ANLO(port));
+	an.reg[1] = I915_READ(PORT_HDCP_ANHI(port));
+	ret = shim->write_an_aksv(intel_dig_port, an.shim);
+	if (ret)
+		return ret;
+
+	r0_prime_gen_start = jiffies;
+
+	memset(&bksv, 0, sizeof(bksv));
+	ret = shim->read_bksv(intel_dig_port, bksv.shim);
+	if (ret)
+		return ret;
+	else if (!intel_hdcp_is_ksv_valid(bksv.shim))
+		return -ENODEV;
+
+	I915_WRITE(PORT_HDCP_BKSVLO(port), bksv.reg[0]);
+	I915_WRITE(PORT_HDCP_BKSVHI(port), bksv.reg[1]);
+
+	ret = shim->repeater_present(intel_dig_port, &repeater_present);
+	if (ret)
+		return ret;
+	if (repeater_present)
+		I915_WRITE(HDCP_REP_CTL,
+			   intel_hdcp_get_repeater_ctl(intel_dig_port));
+
+	ret = shim->toggle_signalling(intel_dig_port, true);
+	if (ret)
+		return ret;
+
+	I915_WRITE(PORT_HDCP_CONF(port), HDCP_CONF_AUTH_AND_ENC);
+
+	/* Wait for R0 ready */
+	if (wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
+		     (HDCP_STATUS_R0_READY | HDCP_STATUS_ENC), 1)) {
+		DRM_ERROR("Timed out waiting for R0 ready\n");
+		return -ETIMEDOUT;
+	}
+
+	/*
+	 * Wait for R0' to become available. The spec says 100ms from Aksv, but
+	 * some monitors can take longer than this. We'll set the timeout at
+	 * 300ms just to be sure.
+	 *
+	 * On DP, there's an R0_READY bit available but no such bit
+	 * exists on HDMI. Since the upper-bound is the same, we'll just do
+	 * the stupid thing instead of polling on one and not the other.
+	 */
+	wait_remaining_ms_from_jiffies(r0_prime_gen_start, 300);
+
+	ri.reg = 0;
+	ret = shim->read_ri_prime(intel_dig_port, ri.shim);
+	if (ret)
+		return ret;
+	I915_WRITE(PORT_HDCP_RPRIME(port), ri.reg);
+
+	/* Wait for Ri prime match */
+	if (wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
+		     (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1)) {
+		DRM_ERROR("Timed out waiting for Ri prime match (%x)\n",
+			  I915_READ(PORT_HDCP_STATUS(port)));
+		return -ETIMEDOUT;
+	}
+
+	/* Wait for encryption confirmation */
+	if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port),
+				    HDCP_STATUS_ENC, HDCP_STATUS_ENC, 20)) {
+		DRM_ERROR("Timed out waiting for encryption\n");
+		return -ETIMEDOUT;
+	}
+
+	/*
+	 * XXX: If we have MST-connected devices, we need to enable encryption
+	 * on those as well.
+	 */
+
+	return intel_hdcp_auth_downstream(intel_dig_port, shim);
+}
+
+static
+struct intel_digital_port *conn_to_dig_port(struct intel_connector *connector)
+{
+	return enc_to_dig_port(&intel_attached_encoder(&connector->base)->base);
+}
+
+static int _intel_hdcp_disable(struct intel_connector *connector)
+{
+	struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	enum port port = intel_dig_port->base.port;
+	int ret;
+
+	I915_WRITE(PORT_HDCP_CONF(port), 0);
+	if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port), ~0, 0,
+				    20)) {
+		DRM_ERROR("Failed to disable HDCP, timeout clearing status\n");
+		return -ETIMEDOUT;
+	}
+
+	intel_hdcp_clear_keys(dev_priv);
+
+	ret = connector->hdcp_shim->toggle_signalling(intel_dig_port, false);
+	if (ret) {
+		DRM_ERROR("Failed to disable HDCP signalling\n");
+		return ret;
+	}
+
+	DRM_INFO("HDCP is disabled\n");
+	return 0;
+}
+
+static int _intel_hdcp_enable(struct intel_connector *connector)
+{
+	struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+	int i, ret;
+
+	if (!(I915_READ(SKL_FUSE_STATUS) & SKL_FUSE_PG_DIST_STATUS(1))) {
+		DRM_ERROR("PG1 is disabled, cannot load keys\n");
+		return -ENXIO;
+	}
+
+	for (i = 0; i < KEY_LOAD_TRIES; i++) {
+		ret = intel_hdcp_load_keys(dev_priv);
+		if (!ret)
+			break;
+		intel_hdcp_clear_keys(dev_priv);
+	}
+	if (ret) {
+		DRM_ERROR("Could not load HDCP keys, (%d)\n", ret);
+		return ret;
+	}
+
+	ret = intel_hdcp_auth(conn_to_dig_port(connector),
+			      connector->hdcp_shim);
+	if (ret) {
+		DRM_ERROR("Failed to authenticate HDCP (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void intel_hdcp_check_work(struct work_struct *work)
+{
+	struct intel_connector *connector = container_of(to_delayed_work(work),
+							 struct intel_connector,
+							 hdcp_check_work);
+	if (!intel_hdcp_check_link(connector))
+		schedule_delayed_work(&connector->hdcp_check_work,
+				      DRM_HDCP_CHECK_PERIOD_MS);
+}
+
+static void intel_hdcp_prop_work(struct work_struct *work)
+{
+	struct intel_connector *connector = container_of(work,
+							 struct intel_connector,
+							 hdcp_prop_work);
+	struct drm_device *dev = connector->base.dev;
+	struct drm_connector_state *state;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	mutex_lock(&connector->hdcp_mutex);
+
+	/*
+	 * This worker is only used to flip between ENABLED/DESIRED. Either of
+	 * those to UNDESIRED is handled by core. If hdcp_value == UNDESIRED,
+	 * we're running just after hdcp has been disabled, so just exit
+	 */
+	if (connector->hdcp_value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+		state = connector->base.state;
+		state->content_protection = connector->hdcp_value;
+	}
+
+	mutex_unlock(&connector->hdcp_mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+}
+
+int intel_hdcp_init(struct intel_connector *connector,
+		    const struct intel_hdcp_shim *hdcp_shim)
+{
+	int ret;
+
+	ret = drm_connector_attach_content_protection_property(
+			&connector->base);
+	if (ret)
+		return ret;
+
+	connector->hdcp_shim = hdcp_shim;
+	mutex_init(&connector->hdcp_mutex);
+	INIT_DELAYED_WORK(&connector->hdcp_check_work, intel_hdcp_check_work);
+	INIT_WORK(&connector->hdcp_prop_work, intel_hdcp_prop_work);
+	return 0;
+}
+
+int intel_hdcp_enable(struct intel_connector *connector)
+{
+	int ret;
+
+	if (!connector->hdcp_shim)
+		return -ENOENT;
+
+	mutex_lock(&connector->hdcp_mutex);
+
+	ret = _intel_hdcp_enable(connector);
+	if (ret)
+		goto out;
+
+	connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+	schedule_work(&connector->hdcp_prop_work);
+	schedule_delayed_work(&connector->hdcp_check_work,
+			      DRM_HDCP_CHECK_PERIOD_MS);
+out:
+	mutex_unlock(&connector->hdcp_mutex);
+	return ret;
+}
+
+int intel_hdcp_disable(struct intel_connector *connector)
+{
+	int ret;
+
+	if (!connector->hdcp_shim)
+		return -ENOENT;
+
+	mutex_lock(&connector->hdcp_mutex);
+
+	connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
+	ret = _intel_hdcp_disable(connector);
+
+	mutex_unlock(&connector->hdcp_mutex);
+	cancel_delayed_work_sync(&connector->hdcp_check_work);
+	return ret;
+}
+
+void intel_hdcp_atomic_check(struct drm_connector *connector,
+			     struct drm_connector_state *old_state,
+			     struct drm_connector_state *new_state)
+{
+	uint64_t old_cp = old_state->content_protection;
+	uint64_t new_cp = new_state->content_protection;
+	struct drm_crtc_state *crtc_state;
+
+	if (!new_state->crtc) {
+		/*
+		 * If the connector is being disabled with CP enabled, mark it
+		 * desired so it's re-enabled when the connector is brought back
+		 */
+		if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+			new_state->content_protection =
+				DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		return;
+	}
+
+	/*
+	 * Nothing to do if the state didn't change, or HDCP was activated since
+	 * the last commit
+	 */
+	if (old_cp == new_cp ||
+	    (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
+	     new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
+		return;
+
+	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
+						   new_state->crtc);
+	crtc_state->mode_changed = true;
+}
+
+/* Implements Part 3 of the HDCP authorization procedure */
+int intel_hdcp_check_link(struct intel_connector *connector)
+{
+	struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	enum port port = intel_dig_port->base.port;
+	int ret = 0;
+
+	if (!connector->hdcp_shim)
+		return -ENOENT;
+
+	mutex_lock(&connector->hdcp_mutex);
+
+	if (connector->hdcp_value == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
+		goto out;
+
+	if (!(I915_READ(PORT_HDCP_STATUS(port)) & HDCP_STATUS_ENC)) {
+		DRM_ERROR("HDCP check failed: link is not encrypted, %x\n",
+			   I915_READ(PORT_HDCP_STATUS(port)));
+		ret = -ENXIO;
+		connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		schedule_work(&connector->hdcp_prop_work);
+		goto out;
+	}
+
+	if (connector->hdcp_shim->check_link(intel_dig_port)) {
+		if (connector->hdcp_value !=
+		    DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+			connector->hdcp_value =
+				DRM_MODE_CONTENT_PROTECTION_ENABLED;
+			schedule_work(&connector->hdcp_prop_work);
+		}
+		goto out;
+	}
+
+	DRM_INFO("HDCP link failed, retrying authentication\n");
+
+	ret = _intel_hdcp_disable(connector);
+	if (ret) {
+		DRM_ERROR("Failed to disable hdcp (%d)\n", ret);
+		connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		schedule_work(&connector->hdcp_prop_work);
+		goto out;
+	}
+
+	ret = _intel_hdcp_enable(connector);
+	if (ret) {
+		DRM_ERROR("Failed to enable hdcp (%d)\n", ret);
+		connector->hdcp_value = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		schedule_work(&connector->hdcp_prop_work);
+		goto out;
+	}
+
+out:
+	mutex_unlock(&connector->hdcp_mutex);
+	return ret;
+}