Documentation/ABI/testing/sysfs-devices-mapping

   1 What:           /sys/devices/uncore_iio_x/dieX
   2 Date:           February 2020
   3 Contact:        Alexander Antonov <alexander.antonov@linux.intel.com>
   4 Description:
   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
  36 What:           /sys/devices/uncore_upi_x/dieX
  37 Date:           March 2022
  38 Contact:        Alexander Antonov <alexander.antonov@linux.intel.com>
  39 Description:
  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