summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-devices-mapping
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-mapping')
-rw-r--r--Documentation/ABI/testing/sysfs-devices-mapping34
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-mapping b/Documentation/ABI/testing/sysfs-devices-mapping
new file mode 100644
index 000000000..8d202bac9
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-mapping
@@ -0,0 +1,34 @@
+What: /sys/devices/uncore_iio_x/dieX
+Date: February 2020
+Contact: Roman Sudarikov <roman.sudarikov@linux.intel.com>
+Description:
+ Each IIO stack (PCIe root port) has its own IIO PMON block, so
+ each dieX file (where X is die number) holds "Segment:Root Bus"
+ for PCIe root port, which can be monitored by that IIO PMON
+ block.
+ For example, on 4-die Xeon platform with up to 6 IIO stacks per
+ die and, therefore, 6 IIO PMON blocks per die, the mapping of
+ IIO PMON block 0 exposes as the following::
+
+ $ ls /sys/devices/uncore_iio_0/die*
+ -r--r--r-- /sys/devices/uncore_iio_0/die0
+ -r--r--r-- /sys/devices/uncore_iio_0/die1
+ -r--r--r-- /sys/devices/uncore_iio_0/die2
+ -r--r--r-- /sys/devices/uncore_iio_0/die3
+
+ $ tail /sys/devices/uncore_iio_0/die*
+ ==> /sys/devices/uncore_iio_0/die0 <==
+ 0000:00
+ ==> /sys/devices/uncore_iio_0/die1 <==
+ 0000:40
+ ==> /sys/devices/uncore_iio_0/die2 <==
+ 0000:80
+ ==> /sys/devices/uncore_iio_0/die3 <==
+ 0000:c0
+
+ Which means::
+
+ IIO PMU 0 on die 0 belongs to PCI RP on bus 0x00, domain 0x0000
+ IIO PMU 0 on die 1 belongs to PCI RP on bus 0x40, domain 0x0000
+ IIO PMU 0 on die 2 belongs to PCI RP on bus 0x80, domain 0x0000
+ IIO PMU 0 on die 3 belongs to PCI RP on bus 0xc0, domain 0x0000