On 21/10/2026 15:39, Leo Yan wrote:

On Mon, Oct 12, 2026 at 04:05:21PM -0700, Amir Ayupov wrote:

[...]

...

--- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -30,6 +30,12 @@ #define CS_CFG_MATCH_CLASS_SRC_ALL 0x0001 /* match any source */ #define CS_CFG_MATCH_CLASS_SRC_ETM4 0x0002 /* match any ETMv4 device */

It is good to introduce a marco:

#define CS_CFG_MATCH_CLASS_MASK GENMASK_U32(7, 0)

...

+/*

• • flags defining device capabilities a feature can require. A feature loads on
• • a device that matches one of its classes and has all of its capabilities.
• */

+#define CS_CFG_MATCH_CAP_MASK 0x0000ff00

To make the mask explicitly 32-bit unsigned:

#define CS_CFG_MATCH_CAP_MASK GENMASK_U32(15, 8)

...

• /* flags defining device instance matching - used in config match desc data. */ #define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */

Not an issue with this patch, but CS_CFG_MATCH_INST_ANY appears to be unused and could be removed in a separate cleanup patch.

...

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index a816c22c87bc8..1545d64afec01 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -172,7 +172,21 @@ cscfg_alloc_csdev_feat(struct coresight_device *csdev, struct cscfg_feature_desc } /* load one feature into one coresight device */ +/*

• • A feature matches a device that shares one of its class flags and has all of
• • the capability flags it requires.
• */

+static bool cscfg_match_feat_csdev(u32 feat_flags, u32 csdev_flags) +{

• u32 caps = feat_flags & CS_CFG_MATCH_CAP_MASK;
• return (feat_flags & csdev_flags & ~CS_CFG_MATCH_CAP_MASK) &&

•       (csdev_flags & caps) == caps;
  

For clearer comparison conditions:

    /* Class type must be matches */
    if ((feat_flags & CS_CFG_MATCH_CLASS_MASK) !=
        (csdev_flags & CS_CFG_MATCH_CLASS_MASK)
        return false;

Why not use FIELD_GET() to compare to make it more explicit ?

    /* No required capabilities miss from the device */
    if (feat_flags & ~csdev_flags & CS_CFG_MATCH_CAP_MASK)
        return false;

Same here.

Suzuki>

    return true;

Thanks, Leo