[PATCH v8 15/17] drm/mst: Add support for QUERY_STREAM_ENCRYPTION_STATUS MST sideband message
Lyude Paul
lyude at redhat.com
Tue Aug 18 22:12:16 UTC 2020
Just one small comment
On Tue, 2020-08-18 at 11:39 -0400, Sean Paul wrote:
> From: Sean Paul <seanpaul at chromium.org>
>
> Used to query whether an MST stream is encrypted or not.
>
> Cc: Lyude Paul <lyude at redhat.com>
> Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
>
> Link:
> https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-14-sean@poorly.run
> #v4
> Link:
> https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-15-sean@poorly.run
> #v5
> Link:
> https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-15-sean@poorly.run
> #v6
> Link:
> https://patchwork.freedesktop.org/patch/msgid/20200623155907.22961-16-sean@poorly.run
> #v7
>
> Changes in v4:
> -Added to the set
> Changes in v5:
> -None
> Changes in v6:
> -Use FIELD_PREP to generate request buffer bitfields (Lyude)
> -Add mst selftest and dump/decode_sideband_req for QSES (Lyude)
> Changes in v7:
> -None
> Changes in v8:
> -Reverse the parsing on the hdcp_*x_device_present bits and leave
> breadcrumb in case this is incorrect (Anshuman)
> ---
> drivers/gpu/drm/drm_dp_mst_topology.c | 150 ++++++++++++++++++
> .../drm/selftests/test-drm_dp_mst_helper.c | 17 ++
> include/drm/drm_dp_helper.h | 3 +
> include/drm/drm_dp_mst_helper.h | 44 +++++
> 4 files changed, 214 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 67dd72ea200e..f2b77ef40281 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -20,11 +20,13 @@
> * OF THIS SOFTWARE.
> */
>
> +#include <linux/bitfield.h>
> #include <linux/delay.h>
> #include <linux/errno.h>
> #include <linux/i2c.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> +#include <linux/random.h>
> #include <linux/sched.h>
> #include <linux/seq_file.h>
> #include <linux/iopoll.h>
> @@ -423,6 +425,22 @@ drm_dp_encode_sideband_req(const struct
> drm_dp_sideband_msg_req_body *req,
> memcpy(&buf[idx], req->u.i2c_write.bytes, req-
> >u.i2c_write.num_bytes);
> idx += req->u.i2c_write.num_bytes;
> break;
> + case DP_QUERY_STREAM_ENC_STATUS: {
> + const struct drm_dp_query_stream_enc_status *msg;
> +
> + msg = &req->u.enc_status;
> + buf[idx] = msg->stream_id;
> + idx++;
> + memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
> + idx += sizeof(msg->client_id);
> + buf[idx] = 0;
> + buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
> + buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
> + buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
> + buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
> + idx++;
> + }
> + break;
> }
> raw->cur_len = idx;
> }
> @@ -551,6 +569,20 @@ drm_dp_decode_sideband_req(const struct
> drm_dp_sideband_msg_tx *raw,
> return -ENOMEM;
> }
> break;
> + case DP_QUERY_STREAM_ENC_STATUS:
> + req->u.enc_status.stream_id = buf[idx++];
> + for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
> + req->u.enc_status.client_id[i] = buf[idx++];
> +
> + req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
> + buf[idx]);
> + req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
> + buf[idx]);
> + req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
> + buf[idx]);
> + req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
> + buf[idx]);
> + break;
> }
>
> return 0;
> @@ -629,6 +661,16 @@ drm_dp_dump_sideband_msg_req_body(const struct
> drm_dp_sideband_msg_req_body *req
> req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
> req->u.i2c_write.bytes);
> break;
> + case DP_QUERY_STREAM_ENC_STATUS:
> + P("stream_id=%u client_id=%*ph stream_event=%x "
> + "valid_event=%d stream_behavior=%x valid_behavior=%d",
> + req->u.enc_status.stream_id,
> + (int)ARRAY_SIZE(req->u.enc_status.client_id),
> + req->u.enc_status.client_id, req->u.enc_status.stream_event,
> + req->u.enc_status.valid_stream_event,
> + req->u.enc_status.stream_behavior,
> + req->u.enc_status.valid_stream_behavior);
> + break;
> default:
> P("???\n");
> break;
> @@ -936,6 +978,42 @@ static bool
> drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_ms
> return true;
> }
>
> +static bool
> +drm_dp_sideband_parse_query_stream_enc_status(
> + struct drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + struct drm_dp_query_stream_enc_status_ack_reply *reply;
> +
> + reply = &repmsg->u.enc_status;
> +
> + reply->stream_id = raw->msg[3];
> +
> + reply->reply_signed = raw->msg[2] & BIT(0);
> +
> + /*
> + * NOTE: It's my impression from reading the spec that the below parsing
> + * is correct. However I noticed while testing with an HDCP 1.4 display
> + * through an HDCP 2.2 hub that only bit 3 was set. In that case, I
> + * would expect both bits to be set. So keep the parsing following the
> + * spec, but beware reality might not match the spec (at least for some
> + * configurations).
> + */
> + reply->hdcp_1x_device_present = raw->msg[2] & BIT(4);
> + reply->hdcp_2x_device_present = raw->msg[2] & BIT(3);
> +
> + reply->query_capable_device_present = raw->msg[2] & BIT(5);
> + reply->legacy_device_present = raw->msg[2] & BIT(6);
> + reply->unauthorizable_device_present = raw->msg[2] & BIT(7);
> +
> + reply->auth_completed = !!(raw->msg[1] & BIT(3));
> + reply->encryption_enabled = !!(raw->msg[1] & BIT(4));
> + reply->repeater_present = !!(raw->msg[1] & BIT(5));
> + reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6;
> +
> + return true;
> +}
> +
> static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
> struct drm_dp_sideband_msg_reply_body
> *msg)
> {
> @@ -970,6 +1048,8 @@ static bool drm_dp_sideband_parse_reply(struct
> drm_dp_sideband_msg_rx *raw,
> return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
> case DP_CLEAR_PAYLOAD_ID_TABLE:
> return true; /* since there's nothing to parse */
> + case DP_QUERY_STREAM_ENC_STATUS:
> + return drm_dp_sideband_parse_query_stream_enc_status(raw, msg);
> default:
> DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
> drm_dp_mst_req_type_str(msg->req_type));
> @@ -1121,6 +1201,25 @@ static void build_power_updown_phy(struct
> drm_dp_sideband_msg_tx *msg,
> msg->path_msg = true;
> }
>
> +static int
> +build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8
> stream_id,
> + u8 *q_id)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> +
> + req.req_type = DP_QUERY_STREAM_ENC_STATUS;
> + req.u.enc_status.stream_id = stream_id;
> + memcpy(req.u.enc_status.client_id, q_id,
> + sizeof(req.u.enc_status.client_id));
> + req.u.enc_status.stream_event = 0;
> + req.u.enc_status.valid_stream_event = false;
> + req.u.enc_status.stream_behavior = 0;
> + req.u.enc_status.valid_stream_behavior = false;
> +
> + drm_dp_encode_sideband_req(&req, msg);
> + return 0;
> +}
> +
> static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
> struct drm_dp_vcpi *vcpi)
> {
> @@ -3153,6 +3252,57 @@ int drm_dp_send_power_updown_phy(struct
> drm_dp_mst_topology_mgr *mgr,
> }
> EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
>
> +int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + struct drm_dp_query_stream_enc_status_ack_reply *status)
> +{
> + struct drm_dp_sideband_msg_tx *txmsg;
> + u8 nonce[7];
> + int len, ret;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg)
> + return -ENOMEM;
> +
> + port = drm_dp_mst_topology_get_port_validated(mgr, port);
> + if (!port) {
> + ret = -EINVAL;
> + goto out_get_port;
> + }
> +
> + get_random_bytes(nonce, sizeof(nonce));
> +
> + /*
> + * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
> + * transaction at the MST Branch device directly connected to the
> + * Source"
> + */
> + txmsg->dst = mgr->mst_primary;
> +
> + len = build_query_stream_enc_status(txmsg, port->vcpi.vcpi, nonce);
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
> + if (ret < 0) {
> + goto out;
> + } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
> + DRM_DEBUG_KMS("query encryption status nak received\n");
Should probably just use drm_dbg_kms() here
Otherwise:
Reviewed-by: Lyude Paul <lyude at redhat.com>
> + ret = -ENXIO;
> + goto out;
> + }
> +
> + ret = 0;
> + memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
> +
> +out:
> + drm_dp_mst_topology_put_port(port);
> +out_get_port:
> + kfree(txmsg);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
> +
> static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
> int id,
> struct drm_dp_payload *payload)
> diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> index bd990d178765..1d696ec001cf 100644
> --- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> +++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> @@ -5,6 +5,8 @@
>
> #define PREFIX_STR "[drm_dp_mst_helper]"
>
> +#include <linux/random.h>
> +
> #include <drm/drm_dp_mst_helper.h>
> #include <drm/drm_print.h>
>
> @@ -237,6 +239,21 @@ int igt_dp_mst_sideband_msg_req_decode(void *unused)
> in.u.i2c_write.bytes = data;
> DO_TEST();
>
> + in.req_type = DP_QUERY_STREAM_ENC_STATUS;
> + in.u.enc_status.stream_id = 1;
> + DO_TEST();
> + get_random_bytes(in.u.enc_status.client_id,
> + sizeof(in.u.enc_status.client_id));
> + DO_TEST();
> + in.u.enc_status.stream_event = 3;
> + DO_TEST();
> + in.u.enc_status.valid_stream_event = 0;
> + DO_TEST();
> + in.u.enc_status.stream_behavior = 3;
> + DO_TEST();
> + in.u.enc_status.valid_stream_behavior = 1;
> + DO_TEST();
> +
> #undef DO_TEST
> return 0;
> }
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 5c2819924862..5e41e15cb5a1 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -1109,6 +1109,9 @@
> #define DP_POWER_DOWN_PHY 0x25
> #define DP_SINK_EVENT_NOTIFY 0x30
> #define DP_QUERY_STREAM_ENC_STATUS 0x38
> +#define DP_QUERY_STREAM_ENC_STATUS_STATE_NO_EXIST 0
> +#define DP_QUERY_STREAM_ENC_STATUS_STATE_INACTIVE 1
> +#define DP_QUERY_STREAM_ENC_STATUS_STATE_ACTIVE 2
>
> /* DP 1.2 MST sideband reply types */
> #define DP_SIDEBAND_REPLY_ACK 0x00
> diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
> index 8b9eb4db3381..371eef8798ad 100644
> --- a/include/drm/drm_dp_mst_helper.h
> +++ b/include/drm/drm_dp_mst_helper.h
> @@ -313,6 +313,34 @@ struct drm_dp_remote_i2c_write_ack_reply {
> u8 port_number;
> };
>
> +struct drm_dp_query_stream_enc_status_ack_reply {
> + /* Bit[23:16]- Stream Id */
> + u8 stream_id;
> +
> + /* Bit[15]- Signed */
> + bool reply_signed;
> +
> + /* Bit[10:8]- Stream Output Sink Type */
> + bool unauthorizable_device_present;
> + bool legacy_device_present;
> + bool query_capable_device_present;
> +
> + /* Bit[12:11]- Stream Output CP Type */
> + bool hdcp_1x_device_present;
> + bool hdcp_2x_device_present;
> +
> + /* Bit[4]- Stream Authentication */
> + bool auth_completed;
> +
> + /* Bit[3]- Stream Encryption */
> + bool encryption_enabled;
> +
> + /* Bit[2]- Stream Repeater Function Present */
> + bool repeater_present;
> +
> + /* Bit[1:0]- Stream State */
> + u8 state;
> +};
>
> #define DRM_DP_MAX_SDP_STREAMS 16
> struct drm_dp_allocate_payload {
> @@ -374,6 +402,15 @@ struct drm_dp_remote_i2c_write {
> u8 *bytes;
> };
>
> +struct drm_dp_query_stream_enc_status {
> + u8 stream_id;
> + u8 client_id[7]; /* 56-bit nonce */
> + u8 stream_event;
> + bool valid_stream_event;
> + u8 stream_behavior;
> + u8 valid_stream_behavior;
> +};
> +
> /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
> struct drm_dp_port_number_req {
> u8 port_number;
> @@ -422,6 +459,8 @@ struct drm_dp_sideband_msg_req_body {
>
> struct drm_dp_remote_i2c_read i2c_read;
> struct drm_dp_remote_i2c_write i2c_write;
> +
> + struct drm_dp_query_stream_enc_status enc_status;
> } u;
> };
>
> @@ -444,6 +483,8 @@ struct drm_dp_sideband_msg_reply_body {
> struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
> struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
> struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
> +
> + struct drm_dp_query_stream_enc_status_ack_reply enc_status;
> } u;
> };
>
> @@ -808,6 +849,9 @@ drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state
> *state,
> struct drm_dp_mst_port *port);
> int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
> struct drm_dp_mst_port *port, bool power_up);
> +int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + struct drm_dp_query_stream_enc_status_ack_reply *status);
> int __must_check drm_dp_mst_atomic_check(struct drm_atomic_state *state);
>
> void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port);
--
Sincerely,
Lyude Paul (she/her)
Software Engineer at Red Hat
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