1What:           /sys/devices/uncore_iio_x/dieX
2Date:           February 2020
3Contact:        Alexander Antonov <alexander.antonov@linux.intel.com>
4Description:
5                Each IIO stack (PCIe root port) has its own IIO PMON block, so
6                each dieX file (where X is die number) holds "Segment:Root Bus"
7                for PCIe root port, which can be monitored by that IIO PMON
8                block.
9                For example, on 4-die Xeon platform with up to 6 IIO stacks per
10                die and, therefore, 6 IIO PMON blocks per die, the mapping of
11                IIO PMON block 0 exposes as the following::
12
13		    $ ls /sys/devices/uncore_iio_0/die*
14		    -r--r--r-- /sys/devices/uncore_iio_0/die0
15		    -r--r--r-- /sys/devices/uncore_iio_0/die1
16		    -r--r--r-- /sys/devices/uncore_iio_0/die2
17		    -r--r--r-- /sys/devices/uncore_iio_0/die3
18
19		    $ tail /sys/devices/uncore_iio_0/die*
20		    ==> /sys/devices/uncore_iio_0/die0 <==
21		    0000:00
22		    ==> /sys/devices/uncore_iio_0/die1 <==
23		    0000:40
24		    ==> /sys/devices/uncore_iio_0/die2 <==
25		    0000:80
26		    ==> /sys/devices/uncore_iio_0/die3 <==
27		    0000:c0
28
29                Which means::
30
31		    IIO PMU 0 on die 0 belongs to PCI RP on bus 0x00, domain 0x0000
32		    IIO PMU 0 on die 1 belongs to PCI RP on bus 0x40, domain 0x0000
33		    IIO PMU 0 on die 2 belongs to PCI RP on bus 0x80, domain 0x0000
34		    IIO PMU 0 on die 3 belongs to PCI RP on bus 0xc0, domain 0x0000
35
36What:           /sys/devices/uncore_upi_x/dieX
37Date:           March 2022
38Contact:        Alexander Antonov <alexander.antonov@linux.intel.com>
39Description:
40                Each /sys/devices/uncore_upi_X/dieY file holds "upi_Z,die_W"
41                value that means UPI link number X on die Y is connected to UPI
42                link Z on die W and this link between sockets can be monitored
43                by UPI PMON block.
44                For example, 4-die Sapphire Rapids platform has the following
45                UPI 0 topology::
46
47		    # tail /sys/devices/uncore_upi_0/die*
48		    ==> /sys/devices/uncore_upi_0/die0 <==
49		    upi_1,die_1
50		    ==> /sys/devices/uncore_upi_0/die1 <==
51		    upi_0,die_3
52		    ==> /sys/devices/uncore_upi_0/die2 <==
53		    upi_1,die_3
54		    ==> /sys/devices/uncore_upi_0/die3 <==
55		    upi_0,die_1
56
57                Which means::
58
59		    UPI link 0 on die 0 is connected to UPI link 1 on die 1
60		    UPI link 0 on die 1 is connected to UPI link 0 on die 3
61		    UPI link 0 on die 2 is connected to UPI link 1 on die 3
62		    UPI link 0 on die 3 is connected to UPI link 0 on die 1