diff options
| author | 2023-02-21 18:24:12 -0800 | |
|---|---|---|
| committer | 2023-02-21 18:24:12 -0800 | |
| commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
| tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/misc-devices/oxsemi-tornado.rst | |
| download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip | |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
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().
...
Diffstat (limited to '')
| -rw-r--r-- | Documentation/misc-devices/oxsemi-tornado.rst | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/Documentation/misc-devices/oxsemi-tornado.rst b/Documentation/misc-devices/oxsemi-tornado.rst new file mode 100644 index 000000000..b33351bef --- /dev/null +++ b/Documentation/misc-devices/oxsemi-tornado.rst @@ -0,0 +1,131 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================================================================== +Notes on Oxford Semiconductor PCIe (Tornado) 950 serial port devices +==================================================================== + +Oxford Semiconductor PCIe (Tornado) 950 serial port devices are driven +by a fixed 62.5MHz clock input derived from the 100MHz PCI Express clock. + +The baud rate produced by the baud generator is obtained from this input +frequency by dividing it by the clock prescaler, which can be set to any +value from 1 to 63.875 in increments of 0.125, and then the usual 16-bit +divisor is used as with the original 8250, to divide the frequency by a +value from 1 to 65535. Finally a programmable oversampling rate is used +that can take any value from 4 to 16 to divide the frequency further and +determine the actual baud rate used. Baud rates from 15625000bps down +to 0.933bps can be obtained this way. + +By default the oversampling rate is set to 16 and the clock prescaler is +set to 33.875, meaning that the frequency to be used as the reference +for the usual 16-bit divisor is 115313.653, which is close enough to the +frequency of 115200 used by the original 8250 for the same values to be +used for the divisor to obtain the requested baud rates by software that +is unaware of the extra clock controls available. + +The oversampling rate is programmed with the TCR register and the clock +prescaler is programmed with the CPR/CPR2 register pair [OX200]_ [OX952]_ +[OX954]_ [OX958]_. To switch away from the default value of 33.875 for +the prescaler the enhanced mode has to be explicitly enabled though, by +setting bit 4 of the EFR. In that mode setting bit 7 in the MCR enables +the prescaler or otherwise it is bypassed as if the value of 1 was used. +Additionally writing any value to CPR clears CPR2 for compatibility with +old software written for older conventional PCI Oxford Semiconductor +devices that do not have the extra prescaler's 9th bit in CPR2, so the +CPR/CPR2 register pair has to be programmed in the right order. + +By using these parameters rates from 15625000bps down to 1bps can be +obtained, with either exact or highly-accurate actual bit rates for +standard and many non-standard rates. + +Here are the figures for the standard and some non-standard baud rates +(including those quoted in Oxford Semiconductor documentation), giving +the requested rate (r), the actual rate yielded (a) and its deviation +from the requested rate (d), and the values of the oversampling rate +(tcr), the clock prescaler (cpr) and the divisor (div) produced by the +new ``get_divisor`` handler: + +:: + + r: 15625000, a: 15625000.00, d: 0.0000%, tcr: 4, cpr: 1.000, div: 1 + r: 12500000, a: 12500000.00, d: 0.0000%, tcr: 5, cpr: 1.000, div: 1 + r: 10416666, a: 10416666.67, d: 0.0000%, tcr: 6, cpr: 1.000, div: 1 + r: 8928571, a: 8928571.43, d: 0.0000%, tcr: 7, cpr: 1.000, div: 1 + r: 7812500, a: 7812500.00, d: 0.0000%, tcr: 8, cpr: 1.000, div: 1 + r: 4000000, a: 4000000.00, d: 0.0000%, tcr: 5, cpr: 3.125, div: 1 + r: 3686400, a: 3676470.59, d: -0.2694%, tcr: 8, cpr: 2.125, div: 1 + r: 3500000, a: 3496503.50, d: -0.0999%, tcr: 13, cpr: 1.375, div: 1 + r: 3000000, a: 2976190.48, d: -0.7937%, tcr: 14, cpr: 1.500, div: 1 + r: 2500000, a: 2500000.00, d: 0.0000%, tcr: 10, cpr: 2.500, div: 1 + r: 2000000, a: 2000000.00, d: 0.0000%, tcr: 10, cpr: 3.125, div: 1 + r: 1843200, a: 1838235.29, d: -0.2694%, tcr: 16, cpr: 2.125, div: 1 + r: 1500000, a: 1492537.31, d: -0.4975%, tcr: 5, cpr: 8.375, div: 1 + r: 1152000, a: 1152073.73, d: 0.0064%, tcr: 14, cpr: 3.875, div: 1 + r: 921600, a: 919117.65, d: -0.2694%, tcr: 16, cpr: 2.125, div: 2 + r: 576000, a: 576036.87, d: 0.0064%, tcr: 14, cpr: 3.875, div: 2 + r: 460800, a: 460829.49, d: 0.0064%, tcr: 7, cpr: 3.875, div: 5 + r: 230400, a: 230414.75, d: 0.0064%, tcr: 14, cpr: 3.875, div: 5 + r: 115200, a: 115207.37, d: 0.0064%, tcr: 14, cpr: 1.250, div: 31 + r: 57600, a: 57603.69, d: 0.0064%, tcr: 8, cpr: 3.875, div: 35 + r: 38400, a: 38402.46, d: 0.0064%, tcr: 14, cpr: 3.875, div: 30 + r: 19200, a: 19201.23, d: 0.0064%, tcr: 8, cpr: 3.875, div: 105 + r: 9600, a: 9600.06, d: 0.0006%, tcr: 9, cpr: 1.125, div: 643 + r: 4800, a: 4799.98, d: -0.0004%, tcr: 7, cpr: 2.875, div: 647 + r: 2400, a: 2400.02, d: 0.0008%, tcr: 9, cpr: 2.250, div: 1286 + r: 1200, a: 1200.00, d: 0.0000%, tcr: 14, cpr: 2.875, div: 1294 + r: 300, a: 300.00, d: 0.0000%, tcr: 11, cpr: 2.625, div: 7215 + r: 200, a: 200.00, d: 0.0000%, tcr: 16, cpr: 1.250, div: 15625 + r: 150, a: 150.00, d: 0.0000%, tcr: 13, cpr: 2.250, div: 14245 + r: 134, a: 134.00, d: 0.0000%, tcr: 11, cpr: 2.625, div: 16153 + r: 110, a: 110.00, d: 0.0000%, tcr: 12, cpr: 1.000, div: 47348 + r: 75, a: 75.00, d: 0.0000%, tcr: 4, cpr: 5.875, div: 35461 + r: 50, a: 50.00, d: 0.0000%, tcr: 16, cpr: 1.250, div: 62500 + r: 25, a: 25.00, d: 0.0000%, tcr: 16, cpr: 2.500, div: 62500 + r: 4, a: 4.00, d: 0.0000%, tcr: 16, cpr: 20.000, div: 48828 + r: 2, a: 2.00, d: 0.0000%, tcr: 16, cpr: 40.000, div: 48828 + r: 1, a: 1.00, d: 0.0000%, tcr: 16, cpr: 63.875, div: 61154 + +With the baud base set to 15625000 and the unsigned 16-bit UART_DIV_MAX +limitation imposed by ``serial8250_get_baud_rate`` standard baud rates +below 300bps become unavailable in the regular way, e.g. the rate of +200bps requires the baud base to be divided by 78125 and that is beyond +the unsigned 16-bit range. The historic spd_cust feature can still be +used by encoding the values for, the prescaler, the oversampling rate +and the clock divisor (DLM/DLL) as follows to obtain such rates if so +required: + +:: + + 31 29 28 20 19 16 15 0 + +-----+-----------------+-------+-------------------------------+ + |0 0 0| CPR2:CPR | TCR | DLM:DLL | + +-----+-----------------+-------+-------------------------------+ + +Use a value such encoded for the ``custom_divisor`` field along with the +ASYNC_SPD_CUST flag set in the ``flags`` field in ``struct serial_struct`` +passed with the TIOCSSERIAL ioctl(2), such as with the setserial(8) +utility and its ``divisor`` and ``spd_cust`` parameters, and then select +the baud rate of 38400bps. Note that the value of 0 in TCR sets the +oversampling rate to 16 and prescaler values below 1 in CPR2/CPR are +clamped by the driver to 1. + +For example the value of 0x1f4004e2 will set CPR2/CPR, TCR and DLM/DLL +respectively to 0x1f4, 0x0 and 0x04e2, choosing the prescaler value, +the oversampling rate and the clock divisor of 62.500, 16 and 1250 +respectively. These parameters will set the baud rate for the serial +port to 62500000 / 62.500 / 1250 / 16 = 50bps. + +Maciej W. Rozycki <macro@orcam.me.uk> + +.. [OX200] "OXPCIe200 PCI Express Multi-Port Bridge", Oxford Semiconductor, + Inc., DS-0045, 10 Nov 2008, Section "950 Mode", pp. 64-65 + +.. [OX952] "OXPCIe952 PCI Express Bridge to Dual Serial & Parallel Port", + Oxford Semiconductor, Inc., DS-0046, Mar 06 08, Section "950 Mode", + p. 20 + +.. [OX954] "OXPCIe954 PCI Express Bridge to Quad Serial Port", Oxford + Semiconductor, Inc., DS-0047, Feb 08, Section "950 Mode", p. 20 + +.. [OX958] "OXPCIe958 PCI Express Bridge to Octal Serial Port", Oxford + Semiconductor, Inc., DS-0048, Feb 08, Section "950 Mode", p. 20 |
