• Evgeny Pinchuk's avatar
    amdkfd: Add topology module to amdkfd · 5b5c4e40
    Evgeny Pinchuk authored
    This patch adds the topology module to the driver. The topology is exposed to
    userspace through the sysfs.
    
    The calls to add and remove a device to/from topology are done by the radeon
    driver.
    
    v3:
    
    The CPU information, that is provided in the topology section of the amdkfd
    driver, is extracted from the CRAT table. Unlike the CPU information located
    in /sys/devices/system/cpu/cpu*, which is extracted from the SRAT table.
    
    While the CPU information provided by the CRAT and the SRAT tables might be
    identical, the node topology might be different. The SRAT table contains the
    topology of CPU nodes only. The CRAT table contains the topology of CPU and GPU
    nodes together (and can be interleaved). For example CPU node 1 in SRAT can be
    CPU node 3 in CRAT. Furthermore it's worth to mention that the CRAT table
    contains only HSA compatible nodes (nodes which are compliant with the HSA
    spec).
    
    To recap, amdkfd exposes a different kind of topology than the one exposed by
    /sys/devices/system/cpu/cpu even though it may contain similar information.
    
    v4:
    
    The topology module doesn't support uevent handling and doesn't notify the
    userspace about runtime modifications. It is up to the userspace to acquire
    snapshots of the topology information created by the amdkfd and exposed
    in sysfs.
    
    The following is an example of how the topology looks on a Kaveri A10-7850K
    system with amdkfd installed:
    
    /sys/devices/virtual/kfd/kfd/
    |
    --- topology/
          |
          |--- generation_id
          |--- system_properties
          |--- nodes/
                |
                |--- 0/
                     |
                     |--- gpu_id
                     |--- name
                     |--- properties
                     |--- caches/
                          |
                          |--- 0/
                               |
                               |--- properties
                          |--- 1/
                               |
                               |--- properties
                          |--- 2/
                               |
                               |--- properties
                     |--- io_links/
                          |
                     |--- mem_banks/
                          |
                          |--- 0/
                               |
                               |--- properties
                          |--- 1/
                               |
                               |--- properties
                          |--- 2/
                               |
                               |--- properties
                          |--- 3/
                               |
                               |--- properties
    
    v5:
    
    Move amdkfd from drm/radeon/ to drm/amd/
    
    Add a check if dev->gpu pointer is null before accessing it in the
    node_show function in kfd_topology.c
    This situation may occur when amdkfd is loaded and there is a GPU with a CRAT
    table, but that GPU isn't supported by amdkfd
    Signed-off-by: default avatarEvgeny Pinchuk <evgeny.pinchuk@amd.com>
    Signed-off-by: default avatarOded Gabbay <oded.gabbay@amd.com>
    5b5c4e40
kfd_topology.c 31.6 KB