1============================ 2 Core Driver Infrastructure 3============================ 4 5GPU Hardware Structure 6====================== 7 8Each ASIC is a collection of hardware blocks. We refer to them as 9"IPs" (Intellectual Property blocks). Each IP encapsulates certain 10functionality. IPs are versioned and can also be mixed and matched. 11E.g., you might have two different ASICs that both have System DMA (SDMA) 5.x IPs. 12The driver is arranged by IPs. There are driver components to handle 13the initialization and operation of each IP. There are also a bunch 14of smaller IPs that don't really need much if any driver interaction. 15Those end up getting lumped into the common stuff in the soc files. 16The soc files (e.g., vi.c, soc15.c nv.c) contain code for aspects of 17the SoC itself rather than specific IPs. E.g., things like GPU resets 18and register access functions are SoC dependent. 19 20An APU contains more than just CPU and GPU, it also contains all of 21the platform stuff (audio, usb, gpio, etc.). Also, a lot of 22components are shared between the CPU, platform, and the GPU (e.g., 23SMU, PSP, etc.). Specific components (CPU, GPU, etc.) usually have 24their interface to interact with those common components. For things 25like S0i3 there is a ton of coordination required across all the 26components, but that is probably a bit beyond the scope of this 27section. 28 29With respect to the GPU, we have the following major IPs: 30 31GMC (Graphics Memory Controller) 32 This was a dedicated IP on older pre-vega chips, but has since 33 become somewhat decentralized on vega and newer chips. They now 34 have dedicated memory hubs for specific IPs or groups of IPs. We 35 still treat it as a single component in the driver however since 36 the programming model is still pretty similar. This is how the 37 different IPs on the GPU get the memory (VRAM or system memory). 38 It also provides the support for per process GPU virtual address 39 spaces. 40 41IH (Interrupt Handler) 42 This is the interrupt controller on the GPU. All of the IPs feed 43 their interrupts into this IP and it aggregates them into a set of 44 ring buffers that the driver can parse to handle interrupts from 45 different IPs. 46 47PSP (Platform Security Processor) 48 This handles security policy for the SoC and executes trusted 49 applications, and validates and loads firmwares for other blocks. 50 51SMU (System Management Unit) 52 This is the power management microcontroller. It manages the entire 53 SoC. The driver interacts with it to control power management 54 features like clocks, voltages, power rails, etc. 55 56DCN (Display Controller Next) 57 This is the display controller. It handles the display hardware. 58 It is described in more details in :ref:`Display Core <amdgpu-display-core>`. 59 60SDMA (System DMA) 61 This is a multi-purpose DMA engine. The kernel driver uses it for 62 various things including paging and GPU page table updates. It's also 63 exposed to userspace for use by user mode drivers (OpenGL, Vulkan, 64 etc.) 65 66GC (Graphics and Compute) 67 This is the graphics and compute engine, i.e., the block that 68 encompasses the 3D pipeline and and shader blocks. This is by far the 69 largest block on the GPU. The 3D pipeline has tons of sub-blocks. In 70 addition to that, it also contains the CP microcontrollers (ME, PFP, 71 CE, MEC) and the RLC microcontroller. It's exposed to userspace for 72 user mode drivers (OpenGL, Vulkan, OpenCL, etc.) 73 74VCN (Video Core Next) 75 This is the multi-media engine. It handles video and image encode and 76 decode. It's exposed to userspace for user mode drivers (VA-API, 77 OpenMAX, etc.) 78 79Graphics and Compute Microcontrollers 80------------------------------------- 81 82CP (Command Processor) 83 The name for the hardware block that encompasses the front end of the 84 GFX/Compute pipeline. Consists mainly of a bunch of microcontrollers 85 (PFP, ME, CE, MEC). The firmware that runs on these microcontrollers 86 provides the driver interface to interact with the GFX/Compute engine. 87 88 MEC (MicroEngine Compute) 89 This is the microcontroller that controls the compute queues on the 90 GFX/compute engine. 91 92 MES (MicroEngine Scheduler) 93 This is a new engine for managing queues. This is currently unused. 94 95RLC (RunList Controller) 96 This is another microcontroller in the GFX/Compute engine. It handles 97 power management related functionality within the GFX/Compute engine. 98 The name is a vestige of old hardware where it was originally added 99 and doesn't really have much relation to what the engine does now. 100 101Driver Structure 102================ 103 104In general, the driver has a list of all of the IPs on a particular 105SoC and for things like init/fini/suspend/resume, more or less just 106walks the list and handles each IP. 107 108Some useful constructs: 109 110KIQ (Kernel Interface Queue) 111 This is a control queue used by the kernel driver to manage other gfx 112 and compute queues on the GFX/compute engine. You can use it to 113 map/unmap additional queues, etc. 114 115IB (Indirect Buffer) 116 A command buffer for a particular engine. Rather than writing 117 commands directly to the queue, you can write the commands into a 118 piece of memory and then put a pointer to the memory into the queue. 119 The hardware will then follow the pointer and execute the commands in 120 the memory, then returning to the rest of the commands in the ring. 121 122.. _amdgpu_memory_domains: 123 124Memory Domains 125============== 126 127.. kernel-doc:: include/uapi/drm/amdgpu_drm.h 128 :doc: memory domains 129 130Buffer Objects 131============== 132 133.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 134 :doc: amdgpu_object 135 136.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 137 :internal: 138 139PRIME Buffer Sharing 140==================== 141 142.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c 143 :doc: PRIME Buffer Sharing 144 145.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c 146 :internal: 147 148MMU Notifier 149============ 150 151.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c 152 :doc: MMU Notifier 153 154.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c 155 :internal: 156 157AMDGPU Virtual Memory 158===================== 159 160.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 161 :doc: GPUVM 162 163.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 164 :internal: 165 166Interrupt Handling 167================== 168 169.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c 170 :doc: Interrupt Handling 171 172.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c 173 :internal: 174 175IP Blocks 176========= 177 178.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h 179 :doc: IP Blocks 180 181.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h 182 :identifiers: amd_ip_block_type amd_ip_funcs 183