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Thu, 22 Aug 2024 16:44:38 +0000 (GMT) Received: from nalasex01c.na.qualcomm.com (nalasex01c.na.qualcomm.com [10.47.97.35]) by NALASPPMTA05.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 47MGibkZ003017 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Aug 2024 16:44:37 GMT Received: from [10.239.133.211] (10.80.80.8) by nalasex01c.na.qualcomm.com (10.47.97.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Thu, 22 Aug 2024 09:44:34 -0700 Message-ID: Date: Fri, 23 Aug 2024 00:44:31 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/3] coresight: Add support for trace filtering by source To: Suzuki K Poulose , Mike Leach , James Clark , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Mathieu Poirier , Leo Yan , Alexander Shishkin CC: , , , , References: <20240821031348.6837-1-quic_taozha@quicinc.com> <20240821031348.6837-3-quic_taozha@quicinc.com> <5d34d9b6-7571-4db8-847b-6721251efc55@arm.com> Content-Language: en-US From: Tao Zhang In-Reply-To: <5d34d9b6-7571-4db8-847b-6721251efc55@arm.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01c.na.qualcomm.com (10.47.97.35) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: gagUNNu6RbgwUO9w6I1WYdnYY68O5exW X-Proofpoint-ORIG-GUID: gagUNNu6RbgwUO9w6I1WYdnYY68O5exW X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-08-22_10,2024-08-22_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 priorityscore=1501 mlxscore=0 impostorscore=0 bulkscore=0 lowpriorityscore=0 adultscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2407110000 definitions=main-2408220125 On 8/21/2024 11:23 PM, Suzuki K Poulose wrote: > Hi Tao > > On 21/08/2024 04:13, Tao Zhang wrote: >> Some replicators have hard coded filtering of "trace" data, based on the >> source device. This is different from the trace filtering based on >> TraceID, available in the standard programmable replicators. e.g., >> Qualcomm replicators have filtering based on custom trace protocol >> format and is not programmable. >> >> The source device could be connected to the replicator via intermediate >> components (e.g., a funnel). Thus we need platform information from >> the firmware tables to decide the source device corresponding to a >> given output port from the replicator. Given this affects "trace >> path building" and traversing the path back from the sink to source, >> add the concept of "filtering by source" to the generic coresight >> connection. >> > > This looks good, except for some minor comments below. OK, I will remove the comments below in the next version. > >> The specified source will be marked like below in the Devicetree. >> test-replicator { >>      ... ... ... ... >>      out-ports { >>          ... ... ... ... >>          port@0 { >>              reg = <0>; >>              xxx: endpoint { >>                  remote-endpoint = <&xxx>; >>                  filter_src = <&xxx>; <-- To specify the source to >>              };                           be filtered out here. >>          }; >> >>          port@1 { >>              reg = <1>; >>              yyy: endpoint { >>                  remote-endpoint = <&yyy>; >>                  filter_src = <&yyy>; <-- To specify the source to >>              };                           be filtered out here. >>          }; >>      }; >> }; >> >> Signed-off-by: Tao Zhang >> --- >>   drivers/hwtracing/coresight/coresight-core.c  | 136 +++++++++++++++--- >>   .../hwtracing/coresight/coresight-platform.c  |  18 +++ >>   include/linux/coresight.h                     |   5 + >>   3 files changed, 136 insertions(+), 23 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-core.c >> b/drivers/hwtracing/coresight/coresight-core.c >> index 9fc6f6b863e0..d09266a4dd1c 100644 >> --- a/drivers/hwtracing/coresight/coresight-core.c >> +++ b/drivers/hwtracing/coresight/coresight-core.c >> @@ -75,22 +75,57 @@ struct coresight_device >> *coresight_get_percpu_sink(int cpu) >>   } >>   EXPORT_SYMBOL_GPL(coresight_get_percpu_sink); >>   +static struct coresight_device *coresight_get_source(struct >> list_head *path) >> +{ >> +    struct coresight_device *csdev; >> + >> +    if (!path) >> +        return NULL; >> + >> +    csdev = list_first_entry(path, struct coresight_node, link)->csdev; >> +    if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) >> +        return NULL; >> + >> +    return csdev; >> +} >> + >> +/** >> + * coresight_block_source - checks whether the connection matches >> the source >> + * of path if connection is binded to specific source. >> + * @src:    The source device of the trace path >> + * @conn:    The connection of one outport >> + * >> + * Return false if the connection doesn't have a source binded or >> source of the >> + * path matches the source binds to connection. >> + */ >> +static bool coresight_block_source(struct coresight_device *src, >> +                    struct coresight_connection *conn) >> +{ >> +    if (conn->filter_src_fwnode && (conn->filter_src_dev != src)) >> +        return true; >> +    else >> +        return false; >> +} >> + >>   static struct coresight_connection * >> -coresight_find_out_connection(struct coresight_device *src_dev, >> -                  struct coresight_device *dest_dev) >> +coresight_find_out_connection(struct coresight_device *csdev, >> +                  struct coresight_device *out_dev, >> +                  struct coresight_device *trace_src) >>   { >>       int i; >>       struct coresight_connection *conn; >>   -    for (i = 0; i < src_dev->pdata->nr_outconns; i++) { >> -        conn = src_dev->pdata->out_conns[i]; >> -        if (conn->dest_dev == dest_dev) >> +    for (i = 0; i < csdev->pdata->nr_outconns; i++) { >> +        conn = csdev->pdata->out_conns[i]; >> +        if (coresight_block_source(trace_src, conn)) >> +            continue; >> +        if (conn->dest_dev == out_dev) >>               return conn; >>       } >>   -    dev_err(&src_dev->dev, >> -        "couldn't find output connection, src_dev: %s, dest_dev: %s\n", >> -        dev_name(&src_dev->dev), dev_name(&dest_dev->dev)); >> +    dev_err(&csdev->dev, >> +        "couldn't find output connection, csdev: %s, out_dev: %s\n", >> +        dev_name(&csdev->dev), dev_name(&out_dev->dev)); >>         return ERR_PTR(-ENODEV); >>   } >> @@ -251,7 +286,8 @@ static void coresight_disable_sink(struct >> coresight_device *csdev) >>     static int coresight_enable_link(struct coresight_device *csdev, >>                    struct coresight_device *parent, >> -                 struct coresight_device *child) >> +                 struct coresight_device *child, >> +                 struct coresight_device *source) >>   { >>       int link_subtype; >>       struct coresight_connection *inconn, *outconn; >> @@ -259,8 +295,8 @@ static int coresight_enable_link(struct >> coresight_device *csdev, >>       if (!parent || !child) >>           return -EINVAL; >>   -    inconn = coresight_find_out_connection(parent, csdev); >> -    outconn = coresight_find_out_connection(csdev, child); >> +    inconn = coresight_find_out_connection(parent, csdev, source); >> +    outconn = coresight_find_out_connection(csdev, child, source); >>       link_subtype = csdev->subtype.link_subtype; >>         if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && >> IS_ERR(inconn)) >> @@ -273,15 +309,16 @@ static int coresight_enable_link(struct >> coresight_device *csdev, >>     static void coresight_disable_link(struct coresight_device *csdev, >>                      struct coresight_device *parent, >> -                   struct coresight_device *child) >> +                   struct coresight_device *child, >> +                   struct coresight_device *source) >>   { >>       struct coresight_connection *inconn, *outconn; >>         if (!parent || !child) >>           return; >>   -    inconn = coresight_find_out_connection(parent, csdev); >> -    outconn = coresight_find_out_connection(csdev, child); >> +    inconn = coresight_find_out_connection(parent, csdev, source); >> +    outconn = coresight_find_out_connection(csdev, child, source); >>         link_ops(csdev)->disable(csdev, inconn, outconn); >>   } >> @@ -337,7 +374,8 @@ EXPORT_SYMBOL_GPL(coresight_disable_source); >>    * disabled. >>    */ >>   static void coresight_disable_path_from(struct list_head *path, >> -                    struct coresight_node *nd) >> +                    struct coresight_node *nd, >> +                    struct coresight_device *source) > > Apologies, I may not have been clear enough. But we concluded that the > path here is suitable for coresight_get_source(path) and as such we > don't need to explicitly pass the source. Do you mean we don't need to explicitly pass the source on "coresight_disable_path_from", we can pass the "source" to "coresight_disable_link" by the following way? coresight_disable_link(csdev, parent, child, coresight_get_source(path)); > >>   { >>       u32 type; >>       struct coresight_device *csdev, *parent, *child; >> @@ -375,7 +413,7 @@ static void coresight_disable_path_from(struct >> list_head *path, >>           case CORESIGHT_DEV_TYPE_LINK: >>               parent = list_prev_entry(nd, link)->csdev; >>               child = list_next_entry(nd, link)->csdev; >> -            coresight_disable_link(csdev, parent, child); >> +            coresight_disable_link(csdev, parent, child, source); >>               break; >>           default: >>               break; >> @@ -388,7 +426,10 @@ static void coresight_disable_path_from(struct >> list_head *path, >>     void coresight_disable_path(struct list_head *path) >>   { >> -    coresight_disable_path_from(path, NULL); >> +    struct coresight_device *source; >> + >> +    source = coresight_get_source(path); >> +    coresight_disable_path_from(path, NULL, source); >>   } >>   EXPORT_SYMBOL_GPL(coresight_disable_path); >>   @@ -418,7 +459,9 @@ int coresight_enable_path(struct list_head >> *path, enum cs_mode mode, >>       u32 type; >>       struct coresight_node *nd; >>       struct coresight_device *csdev, *parent, *child; >> +    struct coresight_device *source; >>   +    source = coresight_get_source(path); >>       list_for_each_entry_reverse(nd, path, link) { >>           csdev = nd->csdev; >>           type = csdev->type; >> @@ -456,7 +499,7 @@ int coresight_enable_path(struct list_head *path, >> enum cs_mode mode, >>           case CORESIGHT_DEV_TYPE_LINK: >>               parent = list_prev_entry(nd, link)->csdev; >>               child = list_next_entry(nd, link)->csdev; >> -            ret = coresight_enable_link(csdev, parent, child); >> +            ret = coresight_enable_link(csdev, parent, child, source); >>               if (ret) >>                   goto err; >>               break; >> @@ -468,7 +511,7 @@ int coresight_enable_path(struct list_head *path, >> enum cs_mode mode, >>   out: >>       return ret; >>   err: >> -    coresight_disable_path_from(path, nd); >> +    coresight_disable_path_from(path, nd, source); >>       goto out; >>   } >>   @@ -619,6 +662,7 @@ static void coresight_drop_device(struct >> coresight_device *csdev) >>    * @csdev:    The device to start from. >>    * @sink:    The final sink we want in this path. >>    * @path:    The list to add devices to. >> + * @source:    The trace source device of the path. >>    * >>    * The tree of Coresight device is traversed until @sink is found. >>    * From there the sink is added to the list along with all the >> devices that led >> @@ -627,7 +671,8 @@ static void coresight_drop_device(struct >> coresight_device *csdev) >>    */ >>   static int _coresight_build_path(struct coresight_device *csdev, >>                    struct coresight_device *sink, >> -                 struct list_head *path) >> +                 struct list_head *path, >> +                 struct coresight_device *source) > > minor nit: Please could we reorder the parameter order : > > _coresight_build_path(csdev, source, sink, path) ? > > That makes it much better to read : build a path from "source" to > "sink", from "csdev" All right, I will update in the next version. > >>   { >>       int i, ret; >>       bool found = false; >> @@ -639,7 +684,7 @@ static int _coresight_build_path(struct >> coresight_device *csdev, >>         if (coresight_is_percpu_source(csdev) && >> coresight_is_percpu_sink(sink) && >>           sink == per_cpu(csdev_sink, >> source_ops(csdev)->cpu_id(csdev))) { >> -        if (_coresight_build_path(sink, sink, path) == 0) { >> +        if (_coresight_build_path(sink, sink, path, source) == 0) { >>               found = true; >>               goto out; >>           } >> @@ -650,8 +695,13 @@ static int _coresight_build_path(struct >> coresight_device *csdev, >>           struct coresight_device *child_dev; >>             child_dev = csdev->pdata->out_conns[i]->dest_dev; >> + >> +        if (csdev->pdata->out_conns[i]->filter_src_dev >> +            && (csdev->pdata->out_conns[i]->filter_src_dev != source)) >> +            continue; > > Please reuse coresight_block_source(). i.e., > > if (coresight_block_source(source, csdev->pdata->cout_conns[i])) >     continue; OK, I will update in the next version. > >> + >>           if (child_dev && >> -            _coresight_build_path(child_dev, sink, path) == 0) { >> +            _coresight_build_path(child_dev, sink, path, source) == >> 0) { >>               found = true; >>               break; >>           } >> @@ -696,7 +746,7 @@ struct list_head *coresight_build_path(struct >> coresight_device *source, >>         INIT_LIST_HEAD(path); >>   -    rc = _coresight_build_path(source, sink, path); >> +    rc = _coresight_build_path(source, sink, path, source); >>       if (rc) { >>           kfree(path); >>           return ERR_PTR(rc); >> @@ -924,6 +974,16 @@ static int coresight_orphan_match(struct device >> *dev, void *data) >>       for (i = 0; i < src_csdev->pdata->nr_outconns; i++) { >>           conn = src_csdev->pdata->out_conns[i]; >>   +        /* Fix filter source device before skip the port */ >> +        if ((conn->filter_src_fwnode) && dst_csdev > > minor nit: unnecessary () around conn->filter_src_fwnode OK, I will update in the next version. > >> +            && (conn->filter_src_fwnode == dst_csdev->dev.fwnode)) { >> +            if (dst_csdev->type == CORESIGHT_DEV_TYPE_SOURCE) >> +                conn->filter_src_dev = dst_csdev; >> +            else >> +                dev_warn(&conn->filter_src_dev->dev, >> +                  "Filter source is not a source device\n"); >> +        } > > We could set the still_orphan here instead of down below. > >     /* Fixup filter source link */ >     if (conn->filter_src_fwnode && !conn->filter_src_dev) { >         if (dst_csdev && >             conn->filter_src_fwnode == dst_csdev->dev.fwnode && >             !WARN_ON_ONCE(dst_csdev->type != CORESIGHT_DEV_TYPE_SOURCE) { >             conn->filter_src_dev = dst_csdev; >         else >             still_orphan = true; >     } > > minor nit: Also I think it is high time we add a helper to check if a > devices is SOURCE, something like we did for is_device_tpdm(). e.g., > > > static inline bool coresight_is_device_source(struct coresight_device > *csdev) > { >     return csdev && (csdev->type == CORESIGHT_DEV_TYPE_SOURCE); > } Could you help review the following approach? I will add the helper to coresight-priv.h static inline bool coresight_is_device_source(struct coresight_device *csdev) {     return (csdev && (csdev->type == CORESIGHT_DEV_TYPE_SOURCE)); } Then, calling the help to check if a device is SOURCE in coresight-platform.c and coresight-core.c coresight-platform.c ... ... ... ...         else {             conn.filter_src_dev =  coresight_find_csdev_by_fwnode(conn.filter_src_fwnode);             if (conn.filter_src_dev &&                 !coresight_is_device_source(conn.filter_src_dev))                 dev_warn(&conn.filter_src_dev->dev,                   "Filter source is not a source device\n");         } coresight-core.c ... ... ... ...         if (conn->filter_src_fwnode && !conn->filter_src_dev) {             if (dst_csdev && (conn->filter_src_fwnode == dst_csdev->dev.fwnode)                 && !WARN_ON_ONCE(!coresight_is_device_source(dst_csdev)))                 conn->filter_src_dev = dst_csdev;             else                 still_orphan = true;         } > > >> + >>           /* Skip the port if it's already connected. */ >>           if (conn->dest_dev) >>               continue; >> @@ -953,6 +1013,14 @@ static int coresight_orphan_match(struct device >> *dev, void *data) >>               ret = coresight_add_in_conn(conn); >>               if (ret) >>                   return ret; >> + >> +            /* >> +             * Make sure the device still orphan if there is a >> +             * filter source firmware node but the filter source >> +             * device is null. >> +             */ >> +            if (conn->filter_src_fwnode && !conn->filter_src_dev) >> +                still_orphan = true; > > Could we not move this to the place where we fixup the filter_src_dev > ? See above. OK, I will update in the next version. > >>           } else { >>               /* This component still has an orphan */ >>               still_orphan = true; >> @@ -974,18 +1042,40 @@ static int coresight_fixup_orphan_conns(struct >> coresight_device *csdev) >>                csdev, coresight_orphan_match); >>   } >>   +static int coresight_clear_filter_source(struct device *dev, void >> *data) >> +{ >> +    int i; >> +    struct coresight_device *source = data; >> +    struct coresight_device *csdev = to_coresight_device(dev); >> + >> +    for (i = 0; i < csdev->pdata->nr_outconns; ++i) { >> +        if (csdev->pdata->out_conns[i]->filter_src_dev == source) >> +            csdev->pdata->out_conns[i]->filter_src_dev = NULL; >> +    } >> +    return 0; >> +} >> + >>   /* coresight_remove_conns - Remove other device's references to >> this device */ >>   static void coresight_remove_conns(struct coresight_device *csdev) >>   { >>       int i, j; >>       struct coresight_connection *conn; >>   +    if (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) >> +        bus_for_each_dev(&coresight_bustype, NULL, csdev, >> +                 coresight_clear_filter_source); >> + >>       /* >>        * Remove the input connection references from the destination >> device >>        * for each output connection. >>        */ >>       for (i = 0; i < csdev->pdata->nr_outconns; i++) { >>           conn = csdev->pdata->out_conns[i]; >> +        if (conn->filter_src_fwnode) { >> +            conn->filter_src_dev = NULL; >> +            fwnode_handle_put(conn->filter_src_fwnode); >> +        } >> + >>           if (!conn->dest_dev) >>               continue; >>   diff --git a/drivers/hwtracing/coresight/coresight-platform.c >> b/drivers/hwtracing/coresight/coresight-platform.c >> index 64e171eaad82..6ef4b26f04bb 100644 >> --- a/drivers/hwtracing/coresight/coresight-platform.c >> +++ b/drivers/hwtracing/coresight/coresight-platform.c >> @@ -243,6 +243,24 @@ static int of_coresight_parse_endpoint(struct >> device *dev, >>           conn.dest_fwnode = fwnode_handle_get(rdev_fwnode); >>           conn.dest_port = rendpoint.port; >>   +        /* >> +         * Get the firmware node of the filter source through the >> +         * reference. This could be used to filter the source in >> +         * building path. >> +         */ >> +        conn.filter_src_fwnode = >> +            fwnode_find_reference(&ep->fwnode, "filter-src", 0); >> +        if (IS_ERR(conn.filter_src_fwnode)) >> +            conn.filter_src_fwnode = NULL; >> +        else { >> +            conn.filter_src_dev = >> + coresight_find_csdev_by_fwnode(conn.filter_src_fwnode); >> +            if (conn.filter_src_dev && (conn.filter_src_dev->type >> +                != CORESIGHT_DEV_TYPE_SOURCE)) >> +                dev_warn(&conn.filter_src_dev->dev, >> +                  "Filter source is not a source device\n"); >> +        } >> + >>           new_conn = coresight_add_out_conn(dev, pdata, &conn); >>           if (IS_ERR_VALUE(new_conn)) { >>               fwnode_handle_put(conn.dest_fwnode); >> diff --git a/include/linux/coresight.h b/include/linux/coresight.h >> index f09ace92176e..91a689b4514b 100644 >> --- a/include/linux/coresight.h >> +++ b/include/linux/coresight.h >> @@ -172,6 +172,9 @@ struct coresight_desc { >>    * @dest_dev:    a @coresight_device representation of the component >>           connected to @src_port. NULL until the device is created >>    * @link: Representation of the connection as a sysfs link. >> + * @filter_src_fwnode: filter source component's fwnode handle. >> + * @filter_src_dev: a @coresight_device representation of the >> component that >> +        needs to be filtered. >>    * >>    * The full connection structure looks like this, where in_conns store >>    * references to same connection as the source device's out_conns. >> @@ -200,6 +203,8 @@ struct coresight_connection { >>       struct coresight_device *dest_dev; >>       struct coresight_sysfs_link *link; >>       struct coresight_device *src_dev; >> +    struct fwnode_handle *filter_src_fwnode; >> +    struct coresight_device *filter_src_dev; >>       atomic_t src_refcnt; >>       atomic_t dest_refcnt; >>   }; > > > Suzuki