Patch "coresight: etm4x: Fix missing trctraceidr file in sysfs" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    coresight: etm4x: Fix missing trctraceidr file in sysfs

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     coresight-etm4x-fix-missing-trctraceidr-file-in-sysf.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f3c9f47641e1bbb2b33135846621efbda861f2a0
Author: Mike Leach <mike.leach@xxxxxxxxxx>
Date:   Fri May 12 14:30:54 2023 +0100

    coresight: etm4x: Fix missing trctraceidr file in sysfs
    
    [ Upstream commit 9f37d3798026f9a7447d851a2cb356610852e426 ]
    
    The trace ID patchset adjusted the handling of the TRCTRACEIDR register
    sysfs to allocate on read.
    
    Although this was initally correct, the final version of the patch series
    introduced an error which resulted in the mgmt/trctraceidr file in sysfs
    not being visible.
    
    This patch fixes that issue.
    
    Fixes: df4871204e5d ("coresight: etm4x: Update ETM4 driver to use Trace ID API")
    Reported-by: Junhao He <hejunhao3@xxxxxxxxxx>
    Link: https://lists.linaro.org/archives/list/coresight@xxxxxxxxxxxxxxxx/thread/KK3CVVMRHJWVUORKMFJRSXYCEDFKENQJ/
    Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
    Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
    Link: https://lore.kernel.org/r/20230512133054.235073-1-mike.leach@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 5e62aa40ecd0f..a9f19629f3f84 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -2411,7 +2411,6 @@ static ssize_t trctraceid_show(struct device *dev,
 
 	return sysfs_emit(buf, "0x%x\n", trace_id);
 }
-static DEVICE_ATTR_RO(trctraceid);
 
 struct etmv4_reg {
 	struct coresight_device *csdev;
@@ -2528,13 +2527,23 @@ coresight_etm4x_attr_reg_implemented(struct kobject *kobj,
 	return 0;
 }
 
-#define coresight_etm4x_reg(name, offset)				\
-	&((struct dev_ext_attribute[]) {				\
-	   {								\
-		__ATTR(name, 0444, coresight_etm4x_reg_show, NULL),	\
-		(void *)(unsigned long)offset				\
-	   }								\
-	})[0].attr.attr
+/*
+ * Macro to set an RO ext attribute with offset and show function.
+ * Offset is used in mgmt group to ensure only correct registers for
+ * the ETM / ETE variant are visible.
+ */
+#define coresight_etm4x_reg_showfn(name, offset, showfn) (	\
+	&((struct dev_ext_attribute[]) {			\
+	   {							\
+		__ATTR(name, 0444, showfn, NULL),		\
+		(void *)(unsigned long)offset			\
+	   }							\
+	})[0].attr.attr						\
+	)
+
+/* macro using the default coresight_etm4x_reg_show function */
+#define coresight_etm4x_reg(name, offset)	\
+	coresight_etm4x_reg_showfn(name, offset, coresight_etm4x_reg_show)
 
 static struct attribute *coresight_etmv4_mgmt_attrs[] = {
 	coresight_etm4x_reg(trcpdcr, TRCPDCR),
@@ -2549,7 +2558,7 @@ static struct attribute *coresight_etmv4_mgmt_attrs[] = {
 	coresight_etm4x_reg(trcpidr3, TRCPIDR3),
 	coresight_etm4x_reg(trcoslsr, TRCOSLSR),
 	coresight_etm4x_reg(trcconfig, TRCCONFIGR),
-	&dev_attr_trctraceid.attr,
+	coresight_etm4x_reg_showfn(trctraceid, TRCTRACEIDR, trctraceid_show),
 	coresight_etm4x_reg(trcdevarch, TRCDEVARCH),
 	NULL,
 };