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.

Signed-off-by: Sean Paul <seanp...@chromium.org>
---
 drivers/gpu/drm/i915/Makefile       |   1 +
 drivers/gpu/drm/i915/i915_reg.h     |  83 +++++
 drivers/gpu/drm/i915/intel_atomic.c |  26 +-
 drivers/gpu/drm/i915/intel_ddi.c    |  14 +
 drivers/gpu/drm/i915/intel_drv.h    |  53 +++
 drivers/gpu/drm/i915/intel_hdcp.c   | 636 ++++++++++++++++++++++++++++++++++++
 6 files changed, 811 insertions(+), 2 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_hdcp.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 6c3b0481ef82..1e745508e437 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -87,6 +87,7 @@ i915-y += intel_audio.o \
          intel_fbc.o \
          intel_fifo_underrun.o \
          intel_frontbuffer.o \
+         intel_hdcp.o \
          intel_hotplug.o \
          intel_modes.o \
          intel_overlay.o \
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 68a58cce6ab1..43128030171d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7991,6 +7991,7 @@ enum {
 #define     GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT   8
 #define     GEN9_MEM_LATENCY_LEVEL_2_6_SHIFT   16
 #define     GEN9_MEM_LATENCY_LEVEL_3_7_SHIFT   24
+#define   SKL_PCODE_LOAD_HDCP_KEYS             0x5
 #define   SKL_PCODE_CDCLK_CONTROL              0x7
 #define     SKL_CDCLK_PREPARE_FOR_CHANGE       0x3
 #define     SKL_CDCLK_READY_FOR_CHANGE         0x1
@@ -8285,6 +8286,88 @@ enum skl_power_gate {
 #define  SKL_PW_TO_PG(pw)                      ((pw) - SKL_DISP_PW_1 + SKL_PG1)
 #define  SKL_FUSE_PG_DIST_STATUS(pg)           (1 << (27 - (pg)))
 
+
+/* HDCP Key Registers */
+#define SKL_HDCP_KEY_CONF              _MMIO(0x66c00)
+#define         SKL_HDCP_AKSV_SEND_TRIGGER     BIT(31)
+#define  SKL_HDCP_CLEAR_KEYS_TRIGGER   BIT(30)
+#define SKL_HDCP_KEY_STATUS            _MMIO(0x66c04)
+#define  SKL_HDCP_FUSE_IN_PROGRESS     BIT(7)
+#define  SKL_HDCP_FUSE_ERROR           BIT(6)
+#define  SKL_HDCP_FUSE_DONE            BIT(5)
+#define  SKL_HDCP_KEY_LOAD_STATUS      BIT(1)
+#define  SKL_HDCP_KEY_LOAD_DONE                BIT(0)
+#define SKL_HDCP_AKSV_LO               _MMIO(0x66c10)
+#define SKL_HDCP_AKSV_HI               _MMIO(0x66c14)
+
+/* HDCP Repeater Registers */
+#define SKL_HDCP_REP_CTL               _MMIO(0x66d00)
+#define  SKL_HDCP_DDIB_REP_PRESENT     BIT(30)
+#define  SKL_HDCP_DDIA_REP_PRESENT     BIT(29)
+#define  SKL_HDCP_DDIC_REP_PRESENT     BIT(28)
+#define  SKL_HDCP_DDID_REP_PRESENT     BIT(27)
+#define  SKL_HDCP_DDIF_REP_PRESENT     BIT(26)
+#define  SKL_HDCP_DDIE_REP_PRESENT     BIT(25)
+#define  SKL_HDCP_DDIB_SHA1_M0         (1 << 20)
+#define  SKL_HDCP_DDIA_SHA1_M0         (2 << 20)
+#define  SKL_HDCP_DDIC_SHA1_M0         (3 << 20)
+#define  SKL_HDCP_DDID_SHA1_M0         (4 << 20)
+#define  SKL_HDCP_DDIF_SHA1_M0         (5 << 20)
+#define  SKL_HDCP_DDIE_SHA1_M0         (6 << 20) // Bspec says 5?
+#define  SKL_HDCP_SHA1_BUSY            BIT(16)
+#define  SKL_HDCP_SHA1_READY           BIT(17)
+#define  SKL_HDCP_SHA1_COMPLETE                BIT(18)
+#define  SKL_HDCP_SHA1_V_MATCH         BIT(19)
+#define  SKL_HDCP_SHA1_TEXT_32         (1 << 1)
+#define  SKL_HDCP_SHA1_COMPLETE_HASH   (2 << 1)
+#define  SKL_HDCP_SHA1_TEXT_24         (4 << 1)
+#define  SKL_HDCP_SHA1_TEXT_16         (5 << 1)
+#define  SKL_HDCP_SHA1_TEXT_8          (6 << 1)
+#define  SKL_HDCP_SHA1_TEXT_0          (7 << 1)
+#define SKL_HDCP_SHA_V_PRIME_H0                _MMIO(0x66d04)
+#define SKL_HDCP_SHA_V_PRIME_H1                _MMIO(0x66d08)
+#define SKL_HDCP_SHA_V_PRIME_H2                _MMIO(0x66d0C)
+#define SKL_HDCP_SHA_V_PRIME_H3                _MMIO(0x66d10)
+#define SKL_HDCP_SHA_V_PRIME_H4                _MMIO(0x66d14)
+#define SKL_HDCP_SHA_V_PRIME(h)                _MMIO((0x66d04 + h * 4))
+#define SKL_HDCP_SHA_TEXT              _MMIO(0x66d18)
+
+/* HDCP Auth Registers */
+#define _SKL_PORTA_HDCP_AUTHENC                0x66800
+#define _SKL_PORTB_HDCP_AUTHENC                0x66500
+#define _SKL_PORTC_HDCP_AUTHENC                0x66600
+#define _SKL_PORTD_HDCP_AUTHENC                0x66700
+#define _SKL_PORTE_HDCP_AUTHENC                0x66A00
+#define _SKL_PORTF_HDCP_AUTHENC                0x66900
+#define _SKL_PORT_HDCP_AUTHENC(port, x)        _MMIO(_PICK(port, \
+                                         _SKL_PORTA_HDCP_AUTHENC, \
+                                         _SKL_PORTB_HDCP_AUTHENC, \
+                                         _SKL_PORTC_HDCP_AUTHENC, \
+                                         _SKL_PORTD_HDCP_AUTHENC, \
+                                         _SKL_PORTE_HDCP_AUTHENC, \
+                                         _SKL_PORTF_HDCP_AUTHENC) + x)
+#define SKL_PORT_HDCP_CONF(port)       _SKL_PORT_HDCP_AUTHENC(port, 0x0)
+#define  SKL_HDCP_CONF_CAPTURE_AN      BIT(0)
+#define  SKL_HDCP_CONF_AUTH_AND_ENC    (BIT(1) | BIT(0))
+#define SKL_PORT_HDCP_ANINIT(port)     _SKL_PORT_HDCP_AUTHENC(port, 0x4)
+#define SKL_PORT_HDCP_ANLO(port)       _SKL_PORT_HDCP_AUTHENC(port, 0x8)
+#define SKL_PORT_HDCP_ANHI(port)       _SKL_PORT_HDCP_AUTHENC(port, 0xC)
+#define SKL_PORT_HDCP_BKSVLO(port)     _SKL_PORT_HDCP_AUTHENC(port, 0x10)
+#define SKL_PORT_HDCP_BKSVHI(port)     _SKL_PORT_HDCP_AUTHENC(port, 0x14)
+#define SKL_PORT_HDCP_RPRIME(port)     _SKL_PORT_HDCP_AUTHENC(port, 0x18)
+#define SKL_PORT_HDCP_STATUS(port)     _SKL_PORT_HDCP_AUTHENC(port, 0x1C)
+#define  SKL_HDCP_STATUS_STREAM_A_ENC  BIT(31)
+#define  SKL_HDCP_STATUS_STREAM_B_ENC  BIT(30)
+#define  SKL_HDCP_STATUS_STREAM_C_ENC  BIT(29)
+#define  SKL_HDCP_STATUS_STREAM_D_ENC  BIT(28)
+#define  SKL_HDCP_STATUS_AUTH          BIT(21)
+#define  SKL_HDCP_STATUS_ENC           BIT(20)
+#define  SKL_HDCP_STATUS_RI_MATCH      BIT(19)
+#define  SKL_HDCP_STATUS_R0_READY      BIT(18)
+#define  SKL_HDCP_STATUS_AN_READY      BIT(17)
+#define  SKL_HDCP_STATUS_CIPHER                BIT(16)
+#define  SKL_HDCP_STATUS_FRAME_CNT(x)  ((x >> 8) & 0xff)
+
 /* Per-pipe DDI Function Control */
 #define _TRANS_DDI_FUNC_CTL_A          0x60400
 #define _TRANS_DDI_FUNC_CTL_B          0x61400
diff --git a/drivers/gpu/drm/i915/intel_atomic.c 
b/drivers/gpu/drm/i915/intel_atomic.c
index 36d4e635e4ce..ddf08227d9cb 100644
--- a/drivers/gpu/drm/i915/intel_atomic.c
+++ b/drivers/gpu/drm/i915/intel_atomic.c
@@ -109,12 +109,34 @@ int intel_digital_connector_atomic_check(struct 
drm_connector *conn,
        struct intel_digital_connector_state *old_conn_state =
                to_intel_digital_connector_state(old_state);
        struct drm_crtc_state *crtc_state;
-
-       if (!new_state->crtc)
+       uint64_t old_cp = old_conn_state->base.content_protection;
+       uint64_t new_cp = new_state->content_protection;
+
+       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 0;
+       }
 
        crtc_state = drm_atomic_get_new_crtc_state(new_state->state, 
new_state->crtc);
 
+       if (new_cp != old_cp) {
+               /* Only drivers can set content protection enabled */
+               if (new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+                       new_state->content_protection =
+                               DRM_MODE_CONTENT_PROTECTION_DESIRED;
+
+               /* Involve the encoder/connector to enable/disable CP */
+               if (new_cp == DRM_MODE_CONTENT_PROTECTION_OFF ||
+                   old_cp == DRM_MODE_CONTENT_PROTECTION_OFF)
+                       crtc_state->mode_changed = true;
+       }
+
        /*
         * These properties are handled by fastset, and might not end
         * up in a modeset.
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 933c18fd4258..0e69337f410d 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2432,10 +2432,17 @@ static void intel_enable_ddi(struct intel_encoder 
*encoder,
                             const struct intel_crtc_state *crtc_state,
                             const struct drm_connector_state *conn_state)
 {
+       struct drm_connector *connector = conn_state->connector;
+       struct intel_connector *intel_connector = to_intel_connector(connector);
+
        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
                intel_enable_ddi_hdmi(encoder, crtc_state, conn_state);
        else
                intel_enable_ddi_dp(encoder, crtc_state, conn_state);
+
+       if (conn_state->content_protection ==
+                       DRM_MODE_CONTENT_PROTECTION_DESIRED)
+               intel_hdcp_enable(intel_connector);
 }
 
 static void intel_disable_ddi_dp(struct intel_encoder *encoder,
@@ -2468,10 +2475,17 @@ static void intel_disable_ddi(struct intel_encoder 
*encoder,
                              const struct intel_crtc_state *old_crtc_state,
                              const struct drm_connector_state *old_conn_state)
 {
+       struct drm_connector *connector = old_conn_state->connector;
+       struct intel_connector *intel_connector = to_intel_connector(connector);
+
        if (intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_HDMI))
                intel_disable_ddi_hdmi(encoder, old_crtc_state, old_conn_state);
        else
                intel_disable_ddi_dp(encoder, old_crtc_state, old_conn_state);
+
+       if (old_conn_state->content_protection !=
+                       DRM_MODE_CONTENT_PROTECTION_OFF)
+               intel_hdcp_disable(intel_connector);
 }
 
 static void bxt_ddi_pre_pll_enable(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 47d022d48718..8924004575b8 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -299,6 +299,49 @@ struct intel_panel {
        } backlight;
 };
 
+struct intel_hdcp_shim {
+       /* Outputs the transmitter's An and Aksv values to the receiver. */
+       int (*write_an_aksv)(struct intel_digital_port *intel_dig_port, u8 *an);
+
+       /* Reads the receiver's key selection vector */
+       int (*read_bksv)(struct intel_digital_port *intel_dig_port, u8 *bksv);
+
+       /*
+        * Reads BINFO from DP receivers and BSTATUS from HDMI receivers. The
+        * definitions are the same in the respective specs, but the names are
+        * different. Call it BSTATUS since that's the name the HDMI spec
+        * uses and it was there first.
+        */
+       int (*read_bstatus)(struct intel_digital_port *intel_dig_port,
+                           u8 *bstatus);
+
+       /* Determines whether a repeater is present downstream */
+       int (*repeater_present)(struct intel_digital_port *intel_dig_port,
+                               bool *repeater_present);
+
+       /* Reads the receiver's Ri' value */
+       int (*read_ri_prime)(struct intel_digital_port *intel_dig_port, u8 *ri);
+
+       /* Determines if the receiver's KSV FIFO is ready for consumption */
+       int (*read_ksv_ready)(struct intel_digital_port *intel_dig_port,
+                             bool *ksv_ready);
+
+       /* Reads the ksv fifo for num_downstream devices */
+       int (*read_ksv_fifo)(struct intel_digital_port *intel_dig_port,
+                            int num_downstream, u8 *ksv_fifo);
+
+       /* Reads a 32-bit part of V' from the receiver */
+       int (*read_v_prime_part)(struct intel_digital_port *intel_dig_port,
+                                int i, u32 *part);
+
+       /* Enables HDCP signalling on the port */
+       int (*toggle_signalling)(struct intel_digital_port *intel_dig_port,
+                                bool enable);
+
+       /* Ensures the link is still protected */
+       bool (*check_link)(struct intel_digital_port *intel_dig_port);
+};
+
 struct intel_connector {
        struct drm_connector base;
        /*
@@ -330,6 +373,9 @@ struct intel_connector {
 
        /* Work struct to schedule a uevent on link train failure */
        struct work_struct modeset_retry_work;
+
+       const struct intel_hdcp_shim *hdcp_shim;
+       struct delayed_work hdcp_work;
 };
 
 struct intel_digital_connector_state {
@@ -1295,6 +1341,8 @@ void intel_ddi_set_vc_payload_alloc(const struct 
intel_crtc_state *crtc_state,
                                    bool state);
 u32 bxt_signal_levels(struct intel_dp *intel_dp);
 uint32_t ddi_signal_levels(struct intel_dp *intel_dp);
+int intel_ddi_enable_hdcp_signalling(struct intel_encoder *intel_encoder);
+int intel_ddi_disable_hdcp_signalling(struct intel_encoder *intel_encoder);
 u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder);
 
 unsigned int intel_fb_align_height(const struct drm_framebuffer *fb,
@@ -1746,6 +1794,11 @@ static inline void 
intel_backlight_device_unregister(struct intel_connector *con
 }
 #endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
 
+/* intel_hdcp.c */
+int intel_hdcp_enable(struct intel_connector *connector);
+int intel_hdcp_disable(struct intel_connector *connector);
+int intel_hdcp_check_link(struct intel_connector *connector);
+void intel_hdcp_work(struct work_struct *work);
 
 /* intel_psr.c */
 void intel_psr_enable(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c 
b/drivers/gpu/drm/i915/intel_hdcp.c
new file mode 100644
index 000000000000..a2a575ed657e
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -0,0 +1,636 @@
+/*
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#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)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies_timeout(500);
+       int ret;
+       bool ksv_ready;
+
+       while (true) {
+               ret = shim->read_ksv_ready(intel_dig_port, &ksv_ready);
+               if (ret)
+                       return ret;
+               if (ksv_ready)
+                       break;
+               if (time_after(jiffies, timeout))
+                       return -ETIMEDOUT;
+               msleep(100);
+       }
+       return 0;
+}
+
+static void intel_hdcp_clear_keys(struct drm_i915_private *dev_priv)
+{
+       I915_WRITE(SKL_HDCP_KEY_CONF, SKL_HDCP_CLEAR_KEYS_TRIGGER);
+       I915_WRITE(SKL_HDCP_KEY_STATUS,
+                  SKL_HDCP_KEY_LOAD_DONE | SKL_HDCP_KEY_LOAD_STATUS |
+                  SKL_HDCP_FUSE_IN_PROGRESS | SKL_HDCP_FUSE_ERROR |
+                  SKL_HDCP_FUSE_DONE);
+}
+
+static int intel_hdcp_load_keys(struct drm_i915_private *dev_priv)
+{
+       unsigned long timeout;
+       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)
+       timeout = jiffies + nsecs_to_jiffies_timeout(500 * 1000);
+       while (true) {
+               val = I915_READ(SKL_HDCP_KEY_STATUS);
+               if (val & SKL_HDCP_KEY_LOAD_DONE)
+                       break;
+               if (time_after(jiffies, timeout))
+                       return -ETIMEDOUT;
+               usleep_range(50, 100);
+       }
+       if (!(val & SKL_HDCP_KEY_LOAD_STATUS))
+               return -ENXIO;
+
+       // Send Aksv over to PCH display for use in authentication
+       I915_WRITE(SKL_HDCP_KEY_CONF, SKL_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(SKL_HDCP_SHA_TEXT, sha_text);
+       if (wait_for(I915_READ(SKL_HDCP_REP_CTL) & SKL_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->port;
+       switch(port) {
+       case PORT_A:
+               return SKL_HDCP_DDIA_REP_PRESENT | SKL_HDCP_DDIA_SHA1_M0;
+       case PORT_B:
+               return SKL_HDCP_DDIB_REP_PRESENT | SKL_HDCP_DDIB_SHA1_M0;
+       case PORT_C:
+               return SKL_HDCP_DDIC_REP_PRESENT | SKL_HDCP_DDIC_SHA1_M0;
+       case PORT_D:
+               return SKL_HDCP_DDID_REP_PRESENT | SKL_HDCP_DDID_SHA1_M0;
+       case PORT_E:
+               return SKL_HDCP_DDIE_REP_PRESENT | SKL_HDCP_DDIE_SHA1_M0;
+       default:
+               break;
+       }
+       DRM_ERROR("Unknown port %d\n", port);
+       return -EINVAL;
+}
+
+/* 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;
+       }
+
+       // Poll for ksv list ready (spec says max time allowed is 5s)
+       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(SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_HDCP_SHA1_TEXT_32);
+       for (i = 0; i < num_downstream; i++) {
+               unsigned 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(SKL_HDCP_REP_CTL,
+                                  rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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(SKL_HDCP_REP_CTL, rep_ctl | SKL_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;
+
+       // Finally, tell the HW we're done with the hash and wait for it to ACK
+       I915_WRITE(SKL_HDCP_REP_CTL, rep_ctl | SKL_HDCP_SHA1_COMPLETE_HASH);
+       if (wait_for(I915_READ(SKL_HDCP_REP_CTL) & SKL_HDCP_SHA1_COMPLETE, 1)) {
+               DRM_ERROR("Timed out waiting for SHA1 complete\n");
+               return -ETIMEDOUT;
+       }
+       if (!(I915_READ(SKL_HDCP_REP_CTL) & SKL_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->port;
+
+       // Initialize An with 2 random values and acquire it
+       for (i = 0; i < 2; i++)
+               I915_WRITE(SKL_PORT_HDCP_ANINIT(port), get_random_long());
+       I915_WRITE(SKL_PORT_HDCP_CONF(port), SKL_HDCP_CONF_CAPTURE_AN);
+
+       // Wait for An to be acquired
+       if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) &
+                    SKL_HDCP_STATUS_AN_READY, 1)) {
+               DRM_ERROR("Timed out waiting for An\n");
+               return -ETIMEDOUT;
+       }
+
+       an.reg[0] = I915_READ(SKL_PORT_HDCP_ANLO(port));
+       an.reg[1] = I915_READ(SKL_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;
+
+       I915_WRITE(SKL_PORT_HDCP_BKSVLO(port), bksv.reg[0]);
+       I915_WRITE(SKL_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(SKL_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(SKL_PORT_HDCP_CONF(port), SKL_HDCP_CONF_AUTH_AND_ENC);
+
+       // Wait for R0 ready
+       if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) &
+                    (SKL_HDCP_STATUS_R0_READY | SKL_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
+        * write. 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, 100);
+
+       ri.reg = 0;
+       ret = shim->read_ri_prime(intel_dig_port, ri.shim);
+       if (ret)
+               return ret;
+       I915_WRITE(SKL_PORT_HDCP_RPRIME(port), ri.reg);
+
+       // Wait for Ri prime match
+       if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) &
+                    (SKL_HDCP_STATUS_RI_MATCH | SKL_HDCP_STATUS_ENC), 1)) {
+               DRM_ERROR("Timed out waiting for Ri prime match (%x)\n",
+                         I915_READ(SKL_PORT_HDCP_STATUS(port)));
+               return -ETIMEDOUT;
+       }
+
+       // Wait for encryption confirmation
+       if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) &
+                     SKL_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->port;
+       int ret;
+
+       I915_WRITE(SKL_PORT_HDCP_CONF(port), 0);
+       if (wait_for(I915_READ(SKL_PORT_HDCP_STATUS(port)) == 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;
+}
+
+void intel_hdcp_work(struct work_struct *work)
+{
+       struct intel_connector *connector = container_of(to_delayed_work(work),
+                                                        struct intel_connector,
+                                                        hdcp_work);
+       struct drm_device *dev = connector->base.dev;
+       int ret;
+
+       drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
+       ret = intel_hdcp_check_link(connector);
+       if (!ret)
+               schedule_delayed_work(&connector->hdcp_work,
+                                     DRM_HDCP_CHECK_PERIOD_MS);
+
+       drm_modeset_unlock(&dev->mode_config.connection_mutex);
+}
+
+int intel_hdcp_enable(struct intel_connector *connector)
+{
+       struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+       struct drm_device *dev = &dev_priv->drm;
+       struct drm_connector_state *state = connector->base.state;
+       int ret;
+
+       WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+
+       if (!connector->hdcp_shim)
+               return -ENOENT;
+
+       ret = _intel_hdcp_enable(connector);
+       if (ret)
+               return ret;
+
+       state->content_protection = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+
+       schedule_delayed_work(&connector->hdcp_work, DRM_HDCP_CHECK_PERIOD_MS);
+       return 0;
+}
+
+int intel_hdcp_disable(struct intel_connector *connector)
+{
+       struct drm_i915_private *dev_priv = connector->base.dev->dev_private;
+       struct drm_device *dev = &dev_priv->drm;
+
+       WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+
+       if (!connector->hdcp_shim)
+               return -ENOENT;
+
+       cancel_delayed_work(&connector->hdcp_work);
+
+       return _intel_hdcp_disable(connector);
+}
+
+/* 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 drm_device *dev = &dev_priv->drm;
+       struct drm_connector_state *state = connector->base.state;
+       struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+       enum port port = intel_dig_port->port;
+       int ret;
+
+       WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+
+       if (state->content_protection != DRM_MODE_CONTENT_PROTECTION_ENABLED)
+               return 0;
+
+       if (!connector->hdcp_shim)
+               return -ENOENT;
+
+       if (!(I915_READ(SKL_PORT_HDCP_STATUS(port)) & SKL_HDCP_STATUS_ENC)) {
+               DRM_ERROR("HDCP check failed: link is not encrypted, %x\n",
+                          I915_READ(SKL_PORT_HDCP_STATUS(port)));
+               ret = -ENXIO;
+               goto fail;
+       }
+
+       if (connector->hdcp_shim->check_link(intel_dig_port))
+               return 0;
+
+       DRM_INFO("HDCP link failed, retrying authentication\n");
+
+       ret = _intel_hdcp_disable(connector);
+       if (ret) {
+               DRM_ERROR("Failed to disable hdcp (%d)\n", ret);
+               goto fail;
+       }
+
+       ret = _intel_hdcp_enable(connector);
+       if (ret) {
+               DRM_ERROR("Failed to enable hdcp (%d)\n", ret);
+               goto fail;
+       }
+
+       return 0;
+
+fail:
+       state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+       return ret;
+}
-- 
2.15.0.531.g2ccb3012c9-goog

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