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

Chris Wilson
2017-11-30T09:13:09Z

Quoting Sean Paul (2017-11-30 03:08:58)
> 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;
> + }
> +
> /*
> * 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);
> + }

__wait_for() (useful so that we can track all the horrible polling
code). I hope nothing time critical contends with this path! ;)

> + 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;

err = __intel_wait_for_register(dev_priv,
SKL_HDCP_KEY_STATUS,
SKL_HDCP_KEY_LOAD_DONE,
SKL_HDCP_KEY_LOAD_DONE,
10, 1000, &val);
if (err)
return err;

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)) {

intel_wait_for_register(dev_priv,
SKL_HDCP_REP_CTL,
SKL_HDCP_SHA1_READY,
1,
10, 1000);

The wait_for() macro is massive. If it can be done using
intel_wait_for_register, do so. If not, try to provide a function that
encapsulates the wait_for() with the functionality you need.

The advantage of intel_wait_for_register() is that switches between
polling for a fast response and sleeping for a slow response. For most
registers, they typically respond quickly.
-Chris