From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- Documentation/gpu/tegra.rst | 178 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) create mode 100644 Documentation/gpu/tegra.rst (limited to 'Documentation/gpu/tegra.rst') diff --git a/Documentation/gpu/tegra.rst b/Documentation/gpu/tegra.rst new file mode 100644 index 000000000..d2ed8938c --- /dev/null +++ b/Documentation/gpu/tegra.rst @@ -0,0 +1,178 @@ +=============================================== + drm/tegra NVIDIA Tegra GPU and display driver +=============================================== + +NVIDIA Tegra SoCs support a set of display, graphics and video functions via +the host1x controller. host1x supplies command streams, gathered from a push +buffer provided directly by the CPU, to its clients via channels. Software, +or blocks amongst themselves, can use syncpoints for synchronization. + +Up until, but not including, Tegra124 (aka Tegra K1) the drm/tegra driver +supports the built-in GPU, comprised of the gr2d and gr3d engines. Starting +with Tegra124 the GPU is based on the NVIDIA desktop GPU architecture and +supported by the drm/nouveau driver. + +The drm/tegra driver supports NVIDIA Tegra SoC generations since Tegra20. It +has three parts: + + - A host1x driver that provides infrastructure and access to the host1x + services. + + - A KMS driver that supports the display controllers as well as a number of + outputs, such as RGB, HDMI, DSI, and DisplayPort. + + - A set of custom userspace IOCTLs that can be used to submit jobs to the + GPU and video engines via host1x. + +Driver Infrastructure +===================== + +The various host1x clients need to be bound together into a logical device in +order to expose their functionality to users. The infrastructure that supports +this is implemented in the host1x driver. When a driver is registered with the +infrastructure it provides a list of compatible strings specifying the devices +that it needs. The infrastructure creates a logical device and scan the device +tree for matching device nodes, adding the required clients to a list. Drivers +for individual clients register with the infrastructure as well and are added +to the logical host1x device. + +Once all clients are available, the infrastructure will initialize the logical +device using a driver-provided function which will set up the bits specific to +the subsystem and in turn initialize each of its clients. + +Similarly, when one of the clients is unregistered, the infrastructure will +destroy the logical device by calling back into the driver, which ensures that +the subsystem specific bits are torn down and the clients destroyed in turn. + +Host1x Infrastructure Reference +------------------------------- + +.. kernel-doc:: include/linux/host1x.h + +.. kernel-doc:: drivers/gpu/host1x/bus.c + :export: + +Host1x Syncpoint Reference +-------------------------- + +.. kernel-doc:: drivers/gpu/host1x/syncpt.c + :export: + +KMS driver +========== + +The display hardware has remained mostly backwards compatible over the various +Tegra SoC generations, up until Tegra186 which introduces several changes that +make it difficult to support with a parameterized driver. + +Display Controllers +------------------- + +Tegra SoCs have two display controllers, each of which can be associated with +zero or more outputs. Outputs can also share a single display controller, but +only if they run with compatible display timings. Two display controllers can +also share a single framebuffer, allowing cloned configurations even if modes +on two outputs don't match. A display controller is modelled as a CRTC in KMS +terms. + +On Tegra186, the number of display controllers has been increased to three. A +display controller can no longer drive all of the outputs. While two of these +controllers can drive both DSI outputs and both SOR outputs, the third cannot +drive any DSI. + +Windows +~~~~~~~ + +A display controller controls a set of windows that can be used to composite +multiple buffers onto the screen. While it is possible to assign arbitrary Z +ordering to individual windows (by programming the corresponding blending +registers), this is currently not supported by the driver. Instead, it will +assume a fixed Z ordering of the windows (window A is the root window, that +is, the lowest, while windows B and C are overlaid on top of window A). The +overlay windows support multiple pixel formats and can automatically convert +from YUV to RGB at scanout time. This makes them useful for displaying video +content. In KMS, each window is modelled as a plane. Each display controller +has a hardware cursor that is exposed as a cursor plane. + +Outputs +------- + +The type and number of supported outputs varies between Tegra SoC generations. +All generations support at least HDMI. While earlier generations supported the +very simple RGB interfaces (one per display controller), recent generations no +longer do and instead provide standard interfaces such as DSI and eDP/DP. + +Outputs are modelled as a composite encoder/connector pair. + +RGB/LVDS +~~~~~~~~ + +This interface is no longer available since Tegra124. It has been replaced by +the more standard DSI and eDP interfaces. + +HDMI +~~~~ + +HDMI is supported on all Tegra SoCs. Starting with Tegra210, HDMI is provided +by the versatile SOR output, which supports eDP, DP and HDMI. The SOR is able +to support HDMI 2.0, though support for this is currently not merged. + +DSI +~~~ + +Although Tegra has supported DSI since Tegra30, the controller has changed in +several ways in Tegra114. Since none of the publicly available development +boards prior to Dalmore (Tegra114) have made use of DSI, only Tegra114 and +later are supported by the drm/tegra driver. + +eDP/DP +~~~~~~ + +eDP was first introduced in Tegra124 where it was used to drive the display +panel for notebook form factors. Tegra210 added support for full DisplayPort +support, though this is currently not implemented in the drm/tegra driver. + +Userspace Interface +=================== + +The userspace interface provided by drm/tegra allows applications to create +GEM buffers, access and control syncpoints as well as submit command streams +to host1x. + +GEM Buffers +----------- + +The ``DRM_IOCTL_TEGRA_GEM_CREATE`` IOCTL is used to create a GEM buffer object +with Tegra-specific flags. This is useful for buffers that should be tiled, or +that are to be scanned out upside down (useful for 3D content). + +After a GEM buffer object has been created, its memory can be mapped by an +application using the mmap offset returned by the ``DRM_IOCTL_TEGRA_GEM_MMAP`` +IOCTL. + +Syncpoints +---------- + +The current value of a syncpoint can be obtained by executing the +``DRM_IOCTL_TEGRA_SYNCPT_READ`` IOCTL. Incrementing the syncpoint is achieved +using the ``DRM_IOCTL_TEGRA_SYNCPT_INCR`` IOCTL. + +Userspace can also request blocking on a syncpoint. To do so, it needs to +execute the ``DRM_IOCTL_TEGRA_SYNCPT_WAIT`` IOCTL, specifying the value of +the syncpoint to wait for. The kernel will release the application when the +syncpoint reaches that value or after a specified timeout. + +Command Stream Submission +------------------------- + +Before an application can submit command streams to host1x it needs to open a +channel to an engine using the ``DRM_IOCTL_TEGRA_OPEN_CHANNEL`` IOCTL. Client +IDs are used to identify the target of the channel. When a channel is no +longer needed, it can be closed using the ``DRM_IOCTL_TEGRA_CLOSE_CHANNEL`` +IOCTL. To retrieve the syncpoint associated with a channel, an application +can use the ``DRM_IOCTL_TEGRA_GET_SYNCPT``. + +After opening a channel, submitting command streams is easy. The application +writes commands into the memory backing a GEM buffer object and passes these +to the ``DRM_IOCTL_TEGRA_SUBMIT`` IOCTL along with various other parameters, +such as the syncpoints or relocations used in the job submission. -- cgit v1.2.3