Re: [Intel-gfx] [RFC PATCH 3/6] drm/i915: Add HDCP framework + base implementation

On Fri, Dec 1, 2017 at 2:36 AM, Daniel Vetter daniel@ffwll.ch wrote:

On Fri, Dec 01, 2017 at 12:53:31PM +0530, Ramalingam C wrote:

...

Sean,

IMHO, it will good if we can have all generic hdcp1.4 authentication flow in drm helpers and all interested display drivers to use them.

This Design will make the extending of hdcp easy for other display drivers based on DRM.

We can have the required drm_hdcp_shim type of implementation at drm structure which will be called for platform specific operations (like prepare an, send aksv, program bksv/repeater/r0 and verify sha1 etc)?

I discussed this exact question with Sean Paul, and apparently the hardware designs are too diverse to make shared code much useful. Some hw has the entire hdcp flow in hw, some almost nothing (like i915 here), and then there's everything in between.

Given that Sean has seen a lot more hdcp implementations than we have, that we right now have no other implementation than i915 in upstream and than wrong abstraction is much harder to fix than no abstraction I'm going with Sean's approach of "no generic abstraction" here. Personally I'm not even fully sold on the shim abstraction, but I think by&large that one is fine.

[html fail on the first response, resending in plain text]

I think there's some sharing potential between exynos and i915, but the rockchip stuff is completely different. Even exynos differs in that each step of the authentication process is interrupt driven (iirc). I just don't see a pattern worth abstracting atm. We might be able to share the enable/disable/check song & dance, but let's not worry about abstraction until we have 2 implementations.

...

On Thursday 30 November 2017 08:38 AM, Sean Paul wrote:

...

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 seanpaul@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;
  

We need not perform the mode set for hdcp enable/disable. Authentication and encryption can be started on active port.

Was simpler to implement this way :-) We can fix this by pushing the hdcp enable/disable code into a post-modeset operation. Ville had written the infrastructure for that to fix a few fastboot corner cases. But that infrastructure hasn't landed yet, so probably better to do that in a follow-up.

I also guess that CrOS simply set this to desired every time they enable an external screen, so it won't result in an unecessary modeset.

Actually, we enable only as needed, if there is no HD licensed content on the screen, the link is unencrypted. The UX of doing it through enable/disable is meh, but things are a lot easier to reason about.

...

...

• }
• /*
  • 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);
  

We might want to disable the hdcp before disabling the DDI. Actually we could trigger hdcp disable at connector state change(due to hot-unplug) also.

Yeah this part needs to be reworked a bit, also because the locking doesn't work yet. I think hot-unplug is handled by the worker thread already, it does the mandatory regular polling.

Yeah, this should go above the disable. intel_hdcp_disable() only does transmitter-side operations, but it's certainly better form to wind/unwind in enable/disable.

Sean

-Daniel

...

Thanks, --Ram

...

} 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;

+}

---

Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch