On Tue, 2021-05-25 at 10:59 +1000, Sam McNally wrote:
> Up requests are decoded by drm_dp_sideband_parse_req(), which operates
> on a drm_dp_sideband_msg_rx, unlike down requests. Expand the existing
> self-test helper sideband_msg_req_encode_decode() to copy the message
> contents and length from a drm_dp_sideband_msg_tx to
> drm_dp_sideband_msg_rx and use the parse function under test in place of
> decode. Add an additional helper for testing clearly-invalid up
> messages, verifying that parse rejects them.
>
> Add support for currently-supported up requests to
> drm_dp_dump_sideband_msg_req_body(); add support to
> drm_dp_encode_sideband_req() to allow encoding for the self-tests.
>
> Add self-tests for CONNECTION_STATUS_NOTIFY and RESOURCE_STATUS_NOTIFY.
>
> Signed-off-by: Sam McNally <sammc@xxxxxxxxxxxx>
> ---
>
> Changes in v5:
> - Set mock device name to more clearly attribute error/debug logging to
> the self-test, in particular for cases where failures are expected
>
> Changes in v4:
> - New in v4
>
> drivers/gpu/drm/drm_dp_mst_topology.c | 54 ++++++-
> .../gpu/drm/drm_dp_mst_topology_internal.h | 4 +
> .../drm/selftests/test-drm_dp_mst_helper.c | 149 ++++++++++++++++--
> 3 files changed, 192 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 54604633e65c..573f39a3dc16 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -442,6 +442,37 @@ drm_dp_encode_sideband_req(const struct
> drm_dp_sideband_msg_req_body *req,
> idx++;
> }
> break;
> + case DP_CONNECTION_STATUS_NOTIFY: {
> + const struct drm_dp_connection_status_notify *msg;
> +
> + msg = &req->u.conn_stat;
> + buf[idx] = (msg->port_number & 0xf) << 4;
> + idx++;
> + memcpy(&raw->msg[idx], msg->guid, 16);
> + idx += 16;
> + raw->msg[idx] = 0;
> + raw->msg[idx] |= msg->legacy_device_plug_status ? BIT(6) :
> 0;
> + raw->msg[idx] |= msg->displayport_device_plug_status ?
> BIT(5) : 0;
> + raw->msg[idx] |= msg->message_capability_status ? BIT(4) :
> 0;
> + raw->msg[idx] |= msg->input_port ? BIT(3) : 0;
> + raw->msg[idx] |= FIELD_PREP(GENMASK(2, 0), msg-
> >peer_device_type);
> + idx++;
> + break;
> + }
> + case DP_RESOURCE_STATUS_NOTIFY: {
> + const struct drm_dp_resource_status_notify *msg;
> +
> + msg = &req->u.resource_stat;
> + buf[idx] = (msg->port_number & 0xf) << 4;
> + idx++;
> + memcpy(&raw->msg[idx], msg->guid, 16);
> + idx += 16;
> + buf[idx] = (msg->available_pbn & 0xff00) >> 8;
> + idx++;
> + buf[idx] = (msg->available_pbn & 0xff);
> + idx++;
> + break;
> + }
> }
> raw->cur_len = idx;
> }
> @@ -672,6 +703,22 @@ drm_dp_dump_sideband_msg_req_body(const struct
> drm_dp_sideband_msg_req_body *req
> req->u.enc_status.stream_behavior,
> req->u.enc_status.valid_stream_behavior);
> break;
> + case DP_CONNECTION_STATUS_NOTIFY:
> + P("port=%d guid=%*ph legacy=%d displayport=%d messaging=%d
> input=%d peer_type=%d",
> + req->u.conn_stat.port_number,
> + (int)ARRAY_SIZE(req->u.conn_stat.guid), req-
> >u.conn_stat.guid,
> + req->u.conn_stat.legacy_device_plug_status,
> + req->u.conn_stat.displayport_device_plug_status,
> + req->u.conn_stat.message_capability_status,
> + req->u.conn_stat.input_port,
> + req->u.conn_stat.peer_device_type);
> + break;
> + case DP_RESOURCE_STATUS_NOTIFY:
> + P("port=%d guid=%*ph pbn=%d",
> + req->u.resource_stat.port_number,
> + (int)ARRAY_SIZE(req->u.resource_stat.guid), req-
> >u.resource_stat.guid,
> + req->u.resource_stat.available_pbn);
> + break;
> default:
> P("???\n");
> break;
> @@ -1116,9 +1163,9 @@ static bool
> drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst
> return false;
> }
>
> -static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr
> *mgr,
> - struct drm_dp_sideband_msg_rx *raw,
> - struct drm_dp_sideband_msg_req_body
> *msg)
> +bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_req_body *msg)
> {
> memset(msg, 0, sizeof(*msg));
> msg->req_type = (raw->msg[0] & 0x7f);
> @@ -1134,6 +1181,7 @@ static bool drm_dp_sideband_parse_req(const struct
> drm_dp_mst_topology_mgr *mgr,
> return false;
> }
> }
> +EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_sideband_parse_req);
>
> static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
> u8 port_num, u32 offset, u8 num_bytes, u8
> *bytes)
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology_internal.h
> b/drivers/gpu/drm/drm_dp_mst_topology_internal.h
> index eeda9a61c657..0356a2e0dba1 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology_internal.h
> +++ b/drivers/gpu/drm/drm_dp_mst_topology_internal.h
> @@ -21,4 +21,8 @@ void
> drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body
> *req,
> int indent, struct drm_printer *printer);
>
> +bool
> +drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_req_body *msg);
> #endif /* !_DRM_DP_MST_HELPER_INTERNAL_H_ */
> 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 6b4759ed6bfd..7bbeb1e5bc97 100644
> --- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> +++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> @@ -13,6 +13,10 @@
> #include "../drm_dp_mst_topology_internal.h"
> #include "test-drm_modeset_common.h"
>
> +static void mock_release(struct device *dev)
> +{
> +}
> +
> int igt_dp_mst_calc_pbn_mode(void *ignored)
> {
> int pbn, i;
> @@ -120,27 +124,60 @@ sideband_msg_req_equal(const struct
> drm_dp_sideband_msg_req_body *in,
> static bool
> sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
> {
> - struct drm_dp_sideband_msg_req_body *out;
> + struct drm_dp_sideband_msg_req_body *out = NULL;
> struct drm_printer p = drm_err_printer(PREFIX_STR);
> - struct drm_dp_sideband_msg_tx *txmsg;
> + struct drm_dp_sideband_msg_tx *txmsg = NULL;
> + struct drm_dp_sideband_msg_rx *rxmsg = NULL;
> + struct drm_dp_mst_topology_mgr *mgr = NULL;
> int i, ret;
> - bool result = true;
> + bool result = false;
>
> out = kzalloc(sizeof(*out), GFP_KERNEL);
> if (!out)
> - return false;
> + goto out;
>
> txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> if (!txmsg)
> - return false;
> + goto out;
>
> - drm_dp_encode_sideband_req(in, txmsg);
> - ret = drm_dp_decode_sideband_req(txmsg, out);
> - if (ret < 0) {
> - drm_printf(&p, "Failed to decode sideband request: %d\n",
> - ret);
> - result = false;
> + rxmsg = kzalloc(sizeof(*rxmsg), GFP_KERNEL);
> + if (!rxmsg)
> goto out;
> +
> + mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> + if (!mgr)
> + goto out;
> +
> + mgr->dev = kzalloc(sizeof(*mgr->dev), GFP_KERNEL);
> + if (!mgr->dev)
> + goto out;
> +
> + mgr->dev->dev = kzalloc(sizeof(*mgr->dev->dev), GFP_KERNEL);
> + if (!mgr->dev->dev)
> + goto out;
> +
> + mgr->dev->dev->release = mock_release;
> + mgr->dev->dev->init_name = PREFIX_STR;
> + device_initialize(mgr->dev->dev);
> +
> + drm_dp_encode_sideband_req(in, txmsg);
> + switch (in->req_type) {
> + case DP_CONNECTION_STATUS_NOTIFY:
> + case DP_RESOURCE_STATUS_NOTIFY:
> + memcpy(&rxmsg->msg, txmsg->msg, ARRAY_SIZE(rxmsg->msg));
> + rxmsg->curlen = txmsg->cur_len;
> + if (!drm_dp_sideband_parse_req(mgr, rxmsg, out)) {
> + drm_printf(&p, "Failed to decode sideband
> request\n");
> + goto out;
> + }
> + break;
> + default:
> + ret = drm_dp_decode_sideband_req(txmsg, out);
> + if (ret < 0) {
> + drm_printf(&p, "Failed to decode sideband request:
> %d\n", ret);
> + goto out;
> + }
> + break;
> }
>
> if (!sideband_msg_req_equal(in, out)) {
> @@ -148,9 +185,9 @@ sideband_msg_req_encode_decode(struct
> drm_dp_sideband_msg_req_body *in)
> drm_dp_dump_sideband_msg_req_body(in, 1, &p);
> drm_printf(&p, "Got:\n");
> drm_dp_dump_sideband_msg_req_body(out, 1, &p);
> - result = false;
> goto out;
> }
> + result = true;
>
> switch (in->req_type) {
> case DP_REMOTE_DPCD_WRITE:
> @@ -171,6 +208,66 @@ sideband_msg_req_encode_decode(struct
> drm_dp_sideband_msg_req_body *in)
> out:
> kfree(out);
> kfree(txmsg);
> + kfree(rxmsg);
> + if (mgr) {
> + if (mgr->dev) {
> + put_device(mgr->dev->dev);
> + kfree(mgr->dev);
> + }
> + kfree(mgr);
> + }
> + return result;
> +}
> +
> +static bool
> +sideband_msg_req_parse(int req_type)
> +{
> + struct drm_dp_sideband_msg_req_body *out = NULL;
> + struct drm_printer p = drm_err_printer(PREFIX_STR);
> + struct drm_dp_sideband_msg_rx *rxmsg = NULL;
> + struct drm_dp_mst_topology_mgr *mgr = NULL;
> + bool result = false;
> +
> + out = kzalloc(sizeof(*out), GFP_KERNEL);
> + if (!out)
> + goto out;
> +
> + rxmsg = kzalloc(sizeof(*rxmsg), GFP_KERNEL);
> + if (!rxmsg)
> + goto out;
> +
> + mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> + if (!mgr)
> + goto out;
> +
> + mgr->dev = kzalloc(sizeof(*mgr->dev), GFP_KERNEL);
> + if (!mgr->dev)
> + goto out;
> +
> + mgr->dev->dev = kzalloc(sizeof(*mgr->dev->dev), GFP_KERNEL);
> + if (!mgr->dev->dev)
> + goto out;
> +
> + mgr->dev->dev->release = mock_release;
> + mgr->dev->dev->init_name = PREFIX_STR " expected parse failure";
> + device_initialize(mgr->dev->dev);
> +
> + rxmsg->curlen = 1;
> + rxmsg->msg[0] = req_type & 0x7f;
> + if (drm_dp_sideband_parse_req(mgr, rxmsg, out))
> + drm_printf(&p, "Unexpectedly decoded invalid sideband
> request\n");
> + else
> + result = true;
> +out:
> + kfree(out);
> + kfree(rxmsg);
> + if (mgr) {
> + if (mgr->dev) {
> + put_device(mgr->dev->dev);
> + kfree(mgr->dev);
> + }
> + kfree(mgr);
> + }
> return result;
> }
>
> @@ -268,6 +365,34 @@ int igt_dp_mst_sideband_msg_req_decode(void *unused)
> in.u.enc_status.valid_stream_behavior = 1;
> DO_TEST();
>
> + in.req_type = DP_CONNECTION_STATUS_NOTIFY;
> + in.u.conn_stat.port_number = 0xf;
> + get_random_bytes(in.u.conn_stat.guid, sizeof(in.u.conn_stat.guid));
> + in.u.conn_stat.legacy_device_plug_status = 1;
> + in.u.conn_stat.displayport_device_plug_status = 0;
> + in.u.conn_stat.message_capability_status = 0;
> + in.u.conn_stat.input_port = 0;
> + in.u.conn_stat.peer_device_type = 7;
> + DO_TEST();
> + in.u.conn_stat.displayport_device_plug_status = 1;
> + DO_TEST();
> + in.u.conn_stat.message_capability_status = 1;
> + DO_TEST();
> + in.u.conn_stat.input_port = 1;
> + DO_TEST();
> +
> + in.req_type = DP_RESOURCE_STATUS_NOTIFY;
> + in.u.resource_stat.port_number = 0xf;
> + get_random_bytes(in.u.resource_stat.guid,
> sizeof(in.u.resource_stat.guid));
Do you think you might be up to moving some of the random functions i915 uses
for selftests out of drivers/gpu/drm/i915/selftests/i915_random.h so that we
could use them here and be able to print out the actual seeds being used for
randomness so that failures can be reproduced reliably?
Either way, patches 1-2 are:
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Will have the third reviewed in just a moment, there's some tiny nitpicks w/
it
> + in.u.resource_stat.available_pbn = 0xcdef;
> + DO_TEST();
> +
> +#undef DO_TEST
> +#define DO_TEST(req_type) FAIL_ON(!sideband_msg_req_parse(req_type))
> + DO_TEST(DP_CONNECTION_STATUS_NOTIFY);
> + DO_TEST(DP_RESOURCE_STATUS_NOTIFY);
> +
> + DO_TEST(DP_REMOTE_I2C_WRITE);
> #undef DO_TEST
> return 0;
> }
--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat
