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(). ... --- drivers/gpio/TODO | 206 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 drivers/gpio/TODO (limited to 'drivers/gpio/TODO') diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO new file mode 100644 index 000000000..765607445 --- /dev/null +++ b/drivers/gpio/TODO @@ -0,0 +1,206 @@ +This is a place for planning the ongoing long-term work in the GPIO +subsystem. + + +GPIO descriptors + +Starting with commit 79a9becda894 the GPIO subsystem embarked on a journey +to move away from the global GPIO numberspace and toward a descriptor-based +approach. This means that GPIO consumers, drivers and machine descriptions +ideally have no use or idea of the global GPIO numberspace that has/was +used in the inception of the GPIO subsystem. + +The numberspace issue is the same as to why irq is moving away from irq +numbers to IRQ descriptors. + +The underlying motivation for this is that the GPIO numberspace has become +unmanageable: machine board files tend to become full of macros trying to +establish the numberspace at compile-time, making it hard to add any numbers +in the middle (such as if you missed a pin on a chip) without the numberspace +breaking. + +Machine descriptions such as device tree or ACPI does not have a concept of the +Linux GPIO number as those descriptions are external to the Linux kernel +and treat GPIO lines as abstract entities. + +The runtime-assigned GPIO numberspace (what you get if you assign the GPIO +base as -1 in struct gpio_chip) has also became unpredictable due to factors +such as probe ordering and the introduction of -EPROBE_DEFER making probe +ordering of independent GPIO chips essentially unpredictable, as their base +number will be assigned on a first come first serve basis. + +The best way to get out of the problem is to make the global GPIO numbers +unimportant by simply not using them. GPIO descriptors deal with this. + +Work items: + +- Convert all GPIO device drivers to only #include + +- Convert all consumer drivers to only #include + +- Convert all machine descriptors in "boardfiles" to only + #include , the other option being to convert it + to a machine description such as device tree, ACPI or fwnode that + implicitly does not use global GPIO numbers. + +- When this work is complete (will require some of the items in the + following ongoing work as well) we can delete the old global + numberspace accessors from and eventually delete + altogether. + + +Get rid of + +This header and helpers appeared at one point when there was no proper +driver infrastructure for doing simpler MMIO GPIO devices and there was +no core support for parsing device tree GPIOs from the core library with +the [devm_]gpiod_get() calls we have today that will implicitly go into +the device tree back-end. It is legacy and should not be used in new code. + +Work items: + +- Get rid of struct of_mm_gpio_chip altogether: use the generic MMIO + GPIO for all current users (see below). Delete struct of_mm_gpio_chip, + to_of_mm_gpio_chip(), of_mm_gpiochip_add_data(), of_mm_gpiochip_add() + of_mm_gpiochip_remove() from the kernel. + +- Change all consumer drivers that #include to + #include and stop doing custom parsing of the + GPIO lines from the device tree. This can be tricky and often ivolves + changing boardfiles, etc. + +- Pull semantics for legacy device tree (OF) GPIO lookups into + gpiolib-of.c: in some cases subsystems are doing custom flags and + lookups for polarity inversion, open drain and what not. As we now + handle this with generic OF bindings, pull all legacy handling into + gpiolib so the library API becomes narrow and deep and handle all + legacy bindings internally. (See e.g. commits 6953c57ab172, + 6a537d48461d etc) + +- Delete when all the above is complete and everything + uses or instead. + + +Get rid of + +This legacy header is a one stop shop for anything GPIO is closely tied +to the global GPIO numberspace. The endgame of the above refactorings will +be the removal of and from that point only the specialized +headers under will be used. This requires all the above to +be completed and is expected to take a long time. + + +Collect drivers + +Collect GPIO drivers from arch/* and other places that should be placed +in drivers/gpio/gpio-*. Augment platforms to create platform devices or +similar and probe a proper driver in the gpiolib subsystem. + +In some cases it makes sense to create a GPIO chip from the local driver +for a few GPIOs. Those should stay where they are. + +At the same time it makes sense to get rid of code duplication in existing or +new coming drivers. For example, gpio-ml-ioh should be incorporated into +gpio-pch. + + +Generic MMIO GPIO + +The GPIO drivers can utilize the generic MMIO helper library in many +cases, and the helper library should be as helpful as possible for MMIO +drivers. (drivers/gpio/gpio-mmio.c) + +Work items: + +- Look over and identify any remaining easily converted drivers and + dry-code conversions to MMIO GPIO for maintainers to test + +- Expand the MMIO GPIO or write a new library for regmap-based I/O + helpers for GPIO drivers on regmap that simply use offsets + 0..n in some register to drive GPIO lines + +- Expand the MMIO GPIO or write a new library for port-mapped I/O + helpers (x86 inb()/outb()) and convert port-mapped I/O drivers to use + this with dry-coding and sending to maintainers to test + + +Generic regmap GPIO + +In the very similar way to Generic MMIO GPIO convert the users which can +take advantage of using regmap over direct IO accessors. Note, even in +MMIO case the regmap MMIO with gpio-regmap.c is preferable over gpio-mmio.c. + + +GPIOLIB irqchip + +The GPIOLIB irqchip is a helper irqchip for "simple cases" that should +try to cover any generic kind of irqchip cascaded from a GPIO. + +- Look over and identify any remaining easily converted drivers and + dry-code conversions to gpiolib irqchip for maintainers to test + + +Increase integration with pin control + +There are already ways to use pin control as back-end for GPIO and +it may make sense to bring these subsystems closer. One reason for +creating pin control as its own subsystem was that we could avoid any +use of the global GPIO numbers. Once the above is complete, it may +make sense to simply join the subsystems into one and make pin +multiplexing, pin configuration, GPIO, etc selectable options in one +and the same pin control and GPIO subsystem. + + +Debugfs in place of sysfs + +The old sysfs code that enables simple uses of GPIOs from the +command line is still popular despite the existance of the proper +character device. The reason is that it is simple to use on +root filesystems where you only have a minimal set of tools such +as "cat", "echo" etc. + +The old sysfs still need to be strongly deprecated and removed +as it relies on the global GPIO numberspace that assume a strict +order of global GPIO numbers that do not change between boots +and is independent of probe order. + +To solve this and provide an ABI that people can use for hacks +and development, implement a debugfs interface to manipulate +GPIO lines that can do everything that sysfs can do today: one +directory per gpiochip and one file entry per line: + +/sys/kernel/debug/gpiochip/gpiochip0 +/sys/kernel/debug/gpiochip/gpiochip0/gpio0 +/sys/kernel/debug/gpiochip/gpiochip0/gpio1 +/sys/kernel/debug/gpiochip/gpiochip0/gpio2 +/sys/kernel/debug/gpiochip/gpiochip0/gpio3 +... +/sys/kernel/debug/gpiochip/gpiochip1 +/sys/kernel/debug/gpiochip/gpiochip1/gpio0 +/sys/kernel/debug/gpiochip/gpiochip1/gpio1 +... + +The exact files and design of the debugfs interface can be +discussed but the idea is to provide a low-level access point +for debugging and hacking and to expose all lines without the +need of any exporting. Also provide ample ammunition to shoot +oneself in the foot, because this is debugfs after all. + + +Moving over to immutable irq_chip structures + +Most of the gpio chips implementing interrupt support rely on gpiolib +intercepting some of the irq_chip callbacks, preventing the structures +from being made read-only and forcing duplication of structures that +should otherwise be unique. + +The solution is to call into the gpiolib code when needed (resource +management, enable/disable or unmask/mask callbacks), and to let the +core code know about that by exposing a flag (IRQCHIP_IMMUTABLE) in +the irq_chip structure. The irq_chip structure can then be made unique +and const. + +A small number of drivers have been converted (pl061, tegra186, msm, +amd, apple), and can be used as examples of how to proceed with this +conversion. Note that drivers using the generic irqchip framework +cannot be converted yet, but watch this space! -- cgit v1.2.3