This is Alex' description from the "gpu block diagram" thread, edited to fit as ReST. Originally-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Yann Dirson <ydirson@xxxxxxx> Acked-by: Harry Wentland <harry.wentland@xxxxxxx> --- Documentation/gpu/amdgpu/driver-core.rst | 81 ++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/Documentation/gpu/amdgpu/driver-core.rst b/Documentation/gpu/amdgpu/driver-core.rst index 97f9a9b68924..b870a63c64dd 100644 --- a/Documentation/gpu/amdgpu/driver-core.rst +++ b/Documentation/gpu/amdgpu/driver-core.rst @@ -2,6 +2,87 @@ Core Driver Infrastructure ============================ +GPU hardware structure +====================== + +Each ASIC is a collection of hardware blocks. We refer to them as +"IPs" (Intellectual Property blocks). Each IP encapsulates certain +functionality. IPs are versioned and can also be mixed and matched. +E.g., you might have two different ASICs that both have SDMA 5.x IPs. +The driver is arranged by IPs. There are driver components to handle +the initialization and operation of each IP. There are also a bunch +of smaller IPs that don't really need much if any driver interaction. +Those end up getting lumped into the common stuff in the soc files. +The soc files (e.g., vi.c, soc15.c nv.c) contain code for aspects of +the SoC itself rather than specific IPs. E.g., things like GPU resets +and register access functions are SoC dependent. + +An APU contains more than just CPU and GPU, it also contains all of +the platform stuff (audio, usb, gpio, etc.). Also, a lot of +components are shared between the CPU, platform, and the GPU (e.g., +SMU, PSP, etc.). Specific components (CPU, GPU, etc.) usually have +their interface to interact with those common components. For things +like S0i3 there is a ton of coordination required across all the +components, but that is probably a bit beyond the scope of this +section. + +With respect to the GPU, we have the following major IPs: + +GMC (Graphics Memory Controller) + This was a dedicated IP on older pre-vega chips, but has since + become somewhat decentralized on vega and newer chips. They now + have dedicated memory hubs for specific IPs or groups of IPs. We + still treat it as a single component in the driver however since + the programming model is still pretty similar. This is how the + different IPs on the GPU get the memory (VRAM or system memory). + It also provides the support for per process GPU virtual address + spaces. + +IH (Interrupt Handler) + This is the interrupt controller on the GPU. All of the IPs feed + their interrupts into this IP and it aggregates them into a set of + ring buffers that the driver can parse to handle interrupts from + different IPs. + +PSP (Platform Security Processor) + This handles security policy for the SoC and executes trusted + applications, and validates and loads firmwares for other blocks. + +SMU (System Management Unit) + This is the power management microcontroller. It manages the entire + SoC. The driver interacts with it to control power management + features like clocks, voltages, power rails, etc. + +DCN (Display Controller Next) + This is the display controller. It handles the display hardware. + +SDMA (System DMA) + This is a multi-purpose DMA engine. The kernel driver uses it for + various things including paging and GPU page table updates. It's also + exposed to userspace for use by user mode drivers (OpenGL, Vulkan, + etc.) + +GC (Graphics and Compute) + This is the graphics and compute engine, i.e., the block that + encompasses the 3D pipeline and and shader blocks. This is by far the + largest block on the GPU. The 3D pipeline has tons of sub-blocks. In + addition to that, it also contains the CP microcontrollers (ME, PFP, + CE, MEC) and the RLC microcontroller. It's exposed to userspace for + user mode drivers (OpenGL, Vulkan, OpenCL, etc.) + +VCN (Video Core Next) + This is the multi-media engine. It handles video and image encode and + decode. It's exposed to userspace for user mode drivers (VA-API, + OpenMAX, etc.) + +Driver structure +================ + +In general, the driver has a list of all of the IPs on a particular +SoC and for things like init/fini/suspend/resume, more or less just +walks the list and handles each IP. + + .. _amdgpu_memory_domains: Memory Domains -- 2.31.1
