Commit Graph

5385 Commits

Author SHA1 Message Date
Andrew Turner
548a2ec49b Add PT_GETREGSET
This adds the PT_GETREGSET and PT_SETREGSET ptrace types. These can be
used to access all the registers from a specified core dump note type.
The NT_PRSTATUS and NT_FPREGSET notes are initially supported. Other
machine-dependant types are expected to be added in the future.

The ptrace addr points to a struct iovec pointing at memory to hold the
registers along with its length. On success the length in the iovec is
updated to tell userspace the actual length the kernel wrote or, if the
base address is NULL, the length the kernel would have written.

Because the data field is an int the arguments are backwards when
compared to the Linux PTRACE_GETREGSET call.

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19831
2022-01-27 11:40:34 +00:00
Mark Johnston
706f4a81a8 exec: Introduce the PROC_PS_STRINGS() macro
Rather than fetching the ps_strings address directly from a process'
sysentvec, use this macro.  With stack address randomization the
ps_strings address is no longer fixed.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33704
2022-01-17 16:11:54 -05:00
Mark Johnston
3fc21fdd5f sysent: Add a sv_psstringssz field to struct sysentvec
The size of the ps_strings structure varies between ABIs, so this is
useful for computing the address of the ps_strings structure relative to
the top of the stack when stack address randomization is enabled.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33704
2022-01-17 11:42:07 -05:00
Brooks Davis
0910a41ef3 Revert "syscallarg_t: Add a type for system call arguments"
Missed issues in truss on at least armv7 and powerpcspe need to be
resolved before recommit.

This reverts commit 3889fb8af0.
This reverts commit 1544e0f5d1.
2022-01-12 23:29:20 +00:00
Brooks Davis
1544e0f5d1 syscallarg_t: Add a type for system call arguments
This more clearly differentiates system call arguments from integer
registers and return values. On current architectures it has no effect,
but on architectures where pointers are not integers (CHERI) and may
not even share registers (CHERI-MIPS) it is necessiary to differentiate
between system call arguments (syscallarg_t) and integer register values
(register_t).

Obtained from:	CheriBSD

Reviewed by:	imp, kib
Differential Revision:	https://reviews.freebsd.org/D33780
2022-01-12 22:51:25 +00:00
Andrew Turner
e7961ccd9f Remove Arm barriers for pre-armv6 CPUs
Remove the macros that define the Arm barriers on Armv5 and earlier. We
don't support these CPUs.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33807
2022-01-11 11:22:29 +00:00
Andrew Turner
ac795a774c Remove old arm CPU macros
The _ARM_ARCH_* and _HAVE_ARMv*_INSTRUCTIONS macros are FreeBSD
specific. Remove them as they are unused in the base system.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33806
2022-01-11 11:22:29 +00:00
John Baldwin
7def1e10b3 bus_dma: Deduplicate locking helper functions.
- Move busdma_lock_mutex to subr_bus_dma.c.

- Move _busdma_lock_dflt to subr_bus_dma.c.  This function was named a
  couple of different things previously.  It is not a public API but
  an internal helper used in place of a NULL pointer.  The prototype
  is in <sys/bus_dma.h> as not all backends include
  <sys/bus_dma_internal.h>.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D33694
2022-01-05 13:50:40 -08:00
John Baldwin
85b4607324 Deduplicate bus_dma bounce code.
Move mostly duplicated code in various MD bus_dma backends to support
bounce pages into sys/kern/subr_busdma_bounce.c.  This file is
currently #include'd into the backends rather than compiled standalone
since it requires access to internal members of opaque bus_dma
structures such as bus_dmamap_t and bus_dma_tag_t.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D33684
2022-01-05 13:50:40 -08:00
Hubert Mazur
f21c469dbc Add driver for marvell, a37x0 peripheral clocks
Add driver for Marvell, Armada-37xx peripheral clock.
Register clocks for various peripheral devices in
north bridge or south bridge domain. Dump clock's
domain while verbose boot.

Reviewed by:
Obtained from:		Semihalf
Differential revision:	https://reviews.freebsd.org/D32294
2022-01-04 13:26:35 +01:00
Hubert Mazur
127e4d9524 Add driver for armada, 37x0-tbg-clock
Driver for tbg clocks. Read reference frequency from parent
and modify it depending on parameters read from register.

Reviewed by:		manu
Obtained from:		Semihalf
Differential revision:	https://reviews.freebsd.org/D32293
2022-01-04 13:26:34 +01:00
Hubert Mazur
01b9c59fd2 Add driver for marvell, armada-3700 oscillator
Driver registers new clock device. Clock frequency is set depending
on tenth bit's value obtained from syscon register. Full information
about the clock is dumped if bootverbose is enabled.

Driver was tested on EspressoBin.

Reviewed by:		manu
Obtained from:		Semihalf
Differential revision:	https://reviews.freebsd.org/D32292
2022-01-04 13:26:34 +01:00
Doug Moore
f1e7a532d1 busdma: _bus_dmamap_addseg repaired
A recent change introduced a one-off error into a test allowing
coalescing chunks into segments.  This fixes that error.

broke a check in _bus_dmamap_addseg on many architectures. This change makes it clear that it is not a particular range that is being boundary-checked, but the proposed union of the two adjacent ranges.
Reported by:	se
Reviewed by:	se
Fixes:	c606ab59e7 vm_extern: use standard address checkers everywhere
Differential Revision:	https://reviews.freebsd.org/D33715
2022-01-02 12:37:05 -06:00
Doug Moore
c606ab59e7 vm_extern: use standard address checkers everywhere
Define simple functions for alignment and boundary checks and use them
everywhere instead of having slightly different implementations
scattered about. Define them in vm_extern.h and use them where
possible where vm_extern.h is included.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D33685
2021-12-30 22:09:08 -06:00
Andrew Turner
6e1be96fd2 Add the missing terminator to the bcm_xhci methods
Sponsored by:	The FreeBSD Foundation
2021-12-29 12:20:01 +00:00
John Baldwin
254e4e5b77 Simplify swi for bus_dma.
When a DMA request using bounce pages completes, a swi is triggered to
schedule pending DMA requests using the just-freed bounce pages.  For
a long time this bus_dma swi has been tied to a "virtual memory" swi
(swi_vm).  However, all of the swi_vm implementations are the same and
consist of checking a flag (busdma_swi_pending) which is always true
and if set calling busdma_swi.  I suspect this dates back to the
pre-SMPng days and that the intention was for swi_vm to serve as a
mux.  However, in the current scheme there's no need for the mux.

Instead, remove swi_vm and vm_ih.  Each bus_dma implementation that
uses bounce pages is responsible for creating its own swi (busdma_ih)
which it now schedules directly.  This swi invokes busdma_swi directly
removing the need for busdma_swi_pending.

One consequence is that the swi now works on RISC-V which had previously
failed to invoke busdma_swi from swi_vm.

Reviewed by:	imp, kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D33447
2021-12-28 13:51:25 -08:00
Adrian Chadd
c7f93ee5cc ipq4018_usb_phy: remove old debugging routine
This isn't needed anymore, I know that these work!
2021-12-27 18:33:06 -08:00
Adrian Chadd
777963afb5 qcom_dwc3: add initial Qualcomm SoC DWC3 controller glue
This adds some very simple DWC3 glue for the IPQ4018/IPQ4019.
Other chipsets introduce reset line iteration, some further
clock line iteration and some customisations; I'll look at adding
those later.

This is enough to finally bring up USB 3.0 on my IPQ4018 ASUS
RT-58U router.
2021-12-27 18:25:32 -08:00
Adrian Chadd
86f0c3ec13 ipq4018_usb_phy: add USB 2.0 and 3.0 PHY support
This adds the USB 2.0 and 3.0 PHY support for the IPQ4018/IPQ4019.

All it really needs to do is gate the relevant clocks on/off in the
right order with the right delays.
2021-12-27 18:21:36 -08:00
Adrian Chadd
d11f81afd5 qcom_tcsr: add initial top control and status register (TCSR) support
The Qualcomm TCSR is some top level glue between multiple IP blocks,
both for doing configuration of said IP blocks, some IPC between
them (mostly between multiple execution environments - eg trustzone
and non-TZ), and interrupt status bits for them.

However, for the IPQ4018/IPQ4019, it only is used as a small subset
of IP block configuration.  As for what it actually gets used as
for other Qualcomm chipsets?  Well, that'll have to wait.

It's a bit of a mess in linux and openwrt.  See, every different
SoC support branch ends up with some different TCSR code for it.

So instead, I'm going to land a single TCSR driver that I'm going
to use for the IPQ4018/IPQ4019.  When I add the next chipset, I'll
figure out how to organise things so there's a single TCSR driver
that works for multiple platforms.
2021-12-27 15:56:28 -08:00
Adrian Chadd
d27ba30884 qcom_qup: add initial v1/v2 QUP SPI driver
The Qualcomm Universal Peripherals Engine (QUP) is a unified SPI and I2C
peripheral that ships with a variety of Qualcomm SoCs.

It supports three transfer modes - single PIO, block PIO and DMA.

This driver only supports the single PIO mode, which is enough to
bootstrap the rest of the SPI NAND/NOR support and means I can do
things like read the Wifi calibration data from NOR.  It has some
hardware support code for the other transfer modes as well as
some support for split transfers (ie, transfers with no read or
write phase), but I haven't yet implemented those.

This driver is based on four sources - the linux driver, the u-boot
driver, some initial work done for APQ8064 by mmel@, and the APQ8064
Technical Reference Manual which is surprisingly free and open to
read.  The linux and u-boot drivers approach a variety of things
completely differently, from how PIO is done, the hardware support
for re-ordering bytes in a transfer word and how the CS lines
are used.

Tested:

* IPQ4018, SPI to NAND/NOR flash, PIO only
2021-12-27 15:27:29 -08:00
Adrian Chadd
7b36da4843 qca: add cpufreq into the build
Now that the clock drivers are in the tree, the cpufreq driver will
"just work".

Tested:

* IPQ4018, testing performance of dd from /dev/zero->/dev/null at
  each frequency step.
2021-12-27 13:13:38 -08:00
Adrian Chadd
cd32ac640b Add support for qualcomm clock nodes the the IPQ4018/IPQ4019 clock tree.
Summary: I've tested this with cpufreq_dt, SPI and USB.  They all seem to work fine.

Test Plan: * IPQ4018, boot

Subscribers: imp, andrew

Differential Revision: https://reviews.freebsd.org/D33665
2021-12-27 13:02:31 -08:00
Adrian Chadd
e34a491b35 qcom_clk: add the qualcomm clock nodes for the IPQ4018
These clock nodes are used by the IPQ4018/IPQ4019 and derivatives.
They're also used by other 32 and 64 bit qualcomm parts; so it's
best to put these nodes here in a single qcom_clk driver and add
to it as we grow new Qualcomm SoC support.

Tested:

* IPQ4018, boot

Differential Revision: https://reviews.freebsd.org/D33665
2021-12-27 13:02:30 -08:00
Michal Meloun
6e9119768d tegra/ahci: do not advertise enclosure management facility
It is not implemented in HW.

MFC after:	1 week
2021-12-24 20:36:46 +01:00
Michal Meloun
be01656fa4 tegra124: Implement new get_gate method for tegra124 clocks.
MFC after:	1 week
2021-12-24 20:16:24 +01:00
Adrian Chadd
95a70e9ea8 qca: add the TLMM code into the build
This adds the IPQ4018 TLMM code into the IPQ4018 build.

Differential Revision: https://reviews.freebsd.org/D33554
2021-12-23 10:42:00 -08:00
Adrian Chadd
4abe6533e9 qcom_tlmm: add initial gpio/pinmux controller (TLMM)
The qualcomm TLMM (top level mode manager) is their gpio/pinmux hardware
controller.

Although the pinmux is generic enough to use for the IPQ/APQ series
chips, I'm directly calling the IPQ4018 routines to expedite bring-up.

Notably, I'm not yet implementing the interrupt support - it's not
required at this stage of bring-up.

Differential Revision: https://reviews.freebsd.org/D33554
2021-12-23 10:41:41 -08:00
Andriy Gapon
08ff54dc5b aw_spi: improve I/O stability
This driver does not use DMA at the moment, so some care is needed to
prevent TX FIFO underruns and RX FIFO overflows.
Several improvements are done in oder to minimize chances of those.

First, the interrupt handling is moved to a filter to minimize latency.
Second, FIFO trigger thresholds are configured for both FIFOs.
The TX FIFO threshold is set to 3/4-th of its size and the RX FIFO
threshold is set to 1/4-th of its size.
The interrupt conditions are changed from the empty FIFO and full FIFO
for the TX and RX correspondingly to going below and above the thresholds.

While here I renamed AW_SPI_IER_RF_ERQ to AW_SPI_IER_RF_RDY which is
closer to what the documentation uses, RF_RDY_INT_EN in the interrupt
control register and RX_RDY in the interrupt status register.

Reviewed by:	manu
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D33558
2021-12-20 12:40:17 +02:00
Hans Petter Selasky
48014c6679 Try to fix syntax of "strht" instruction so that clang is happy.
This fixes compilation of usb(4) after 0ec590d24e .

MFC after:	1 week
Sponsored by:	NVIDIA Networking
2021-12-19 13:52:36 +01:00
Hans Petter Selasky
516df15582 Implement suword16() for the 32-bit ARMv6/v7 architecture.
This fixes compilation of usb(4) after 0ec590d24e .

MFC after:	1 week
Sponsored by:	NVIDIA Networking
2021-12-19 12:21:21 +01:00
Andrew Turner
36499dc789 Fix a set but not used warning in the arm GIC driver
Sponsored by:	Innovate UK
2021-12-10 13:29:11 +00:00
Alexander Motin
8493918868 busdma: Remove outdated comments about Giant.
MFC after:	2 weeks
2021-12-09 22:18:53 -05:00
John Baldwin
1a62e9bc00 Add <machine/tls.h> header to hold MD constants and helpers for TLS.
The header exports the following:

- Definition of struct tcb.
- Helpers to get/set the tcb for the current thread.
- TLS_TCB_SIZE (size of TCB)
- TLS_TCB_ALIGN (alignment of TCB)
- TLS_VARIANT_I or TLS_VARIANT_II
- TLS_DTV_OFFSET (bias of pointers in dtv[])
- TLS_TP_OFFSET (bias of "thread pointer" relative to TCB)

Note that TLS_TP_OFFSET does not account for if the unbiased thread
pointer points to the start of the TCB (arm and x86) or the end of the
TCB (MIPS, PowerPC, and RISC-V).

Note also that for amd64, the struct tcb does not include the unused
tcb_spare field included in the current structure in libthr.  libthr
does not use this field, and the existing calls in libc and rtld that
allocate a TCB for amd64 assume it is the size of 3 Elf_Addr's (and
thus do not allocate room for tcb_spare).

A <sys/_tls_variant_i.h> header is used by architectures using
Variant I TLS which uses a common struct tcb.

Reviewed by:	kib (older version of x86/tls.h), jrtc27
Sponsored by:	The University of Cambridge, Google Inc.
Differential Revision:	https://reviews.freebsd.org/D33351
2021-12-09 13:17:13 -08:00
Mateusz Guzik
793c74e415 arm/freescale: remove FBIOSCURSOR
Unbreaks building EFIKA_MX

Fixes:	b9d3b253e2 ("fb: Remove unused cursors ioctls")
Sponsored by:	Rubicon Communications, LLC ("Netgate")
2021-12-09 17:00:43 +00:00
Brooks Davis
547566526f Make struct syscall_args machine independent
After a round of cleanups in late 2020, all definitions are
functionally identical.

This removes a rotted __aligned(8) on arm. It was added in
b7112ead32 and was intended to align the
args member so that 64-bit types (off_t, etc) could be safely read on
armeb compiled with clang. With the removal of armev, this is no
longer needed (armv7 requires that 32-bit aligned reads of 64-bit
values be supported and we enable such support on armv6).  As further
evidence this is unnecessary, cleanups to struct syscall_args have
resulted in args being 32-bit aligned on 32-bit systems.  The sole
effect is to bloat the struct by 4 bytes.

Reviewed by:	kib, jhb, imp
Differential Revision:	https://reviews.freebsd.org/D33308
2021-12-08 18:45:33 +00:00
Gordon Bergling
b86066a15e omap4: Fix a few typos in source code comments
- s/addresss/address/

MFC after:	3 days
2021-12-04 12:13:27 +01:00
Mitchell Horne
0d2224733e Implement GET_STACK_USAGE on remaining archs
This definition enables callers to estimate remaining space on the
kstack, and take action on it. Notably, it enables optimizations in the
GEOM and netgraph subsystems to directly dispatch work items when there
is sufficient stack space, rather than queuing them for a worker thread.

Implement it for riscv, arm, and mips. Remove the #ifdefs, so it will
not go unimplemented elsewhere.

PR:		259157
Reviewed by:	mav, kib, markj (previous version)
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32580
2021-11-30 11:15:56 -04:00
Leandro Lupori
b9f3b63ab2 vt: export RGB offsets with FBIO_GETRGBOFFS
Add a new ioctl to vt to make it possible to export RGB offsets
set by vt drivers. This is needed to fix colors on X and Mesa
on some machines, especially on modern PowerPC64 BE ones.

With the appropriate changes in SCFB, to use this ioctl to find
out the correct RGB offsets, this fixes wrong colors on Talos II
and Blackbird, when used with their built-in video cards.

Reviewed by:		alfredo
Sponsored by:		Instituto de Pesquisas Eldorado (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D29000
2021-11-25 16:39:25 -03:00
Mark Johnston
ecbbe83144 netinet: Deduplicate most in_cksum() implementations
in_cksum() and related routines are implemented separately for each
platform, but only i386 and arm have optimized versions.  Other
platforms' copies of in_cksum.c are identical except for style
differences and support for big-endian CPUs.

Deduplicate the implementations for the rest of the platforms.  This
will make it easier to implement in_cksum() for unmapped mbufs.  On arm
and i386, define HAVE_MD_IN_CKSUM to mean that the MI implementation is
not to be compiled.

No functional change intended.

Reviewed by:	kp, glebius
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33095
2021-11-24 13:31:16 -05:00
Warner Losh
b57e0aa4ef arm: Make machine/reg.h self-contained
Allow inclusion of sys/reg.h w/o pre-requisites by making arm's machine/reg.h
self-contained.

Sponsored by:		Netflix
2021-11-23 21:21:17 -07:00
Mitchell Horne
10fe6f80a6 minidump: Use the provided dump bitset
When constructing the set of dumpable pages, use the bitset provided by
the state argument, rather than assuming vm_page_dump invariably. For
normal kernel minidumps this will be a pointer to vm_page_dump, but when
dumping the live system it will not.

To do this, the functions in vm_dumpset.h are extended to accept the
desired bitset as an argument. Note that this provided bitset is assumed
to be derived from vm_page_dump, and therefore has the same size.

Reviewed by:	kib, markj, jhb
MFC after:	2 weeks
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D31992
2021-11-19 15:05:52 -04:00
Mitchell Horne
1d2d1418b4 minidump: Use provided msgbuf pointer
Don't assume we are dumping the global message buffer, but use the one
provided by the state argument. While here, drop superfluous
cast to char *.

Reviewed by:	markj, jhb
MFC after:	2 weeks
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D31991
2021-11-19 15:05:52 -04:00
Mitchell Horne
681bd71047 minidump: reduce the amount direct accesses to page tables
During a live dump, we may race with updates to the kernel page tables.
This is generally okay; we accept that the state of the system while
dumping may be somewhat inconsistent with its state when the dump was
invoked. However, when walking the kernel page tables, it is important
that we load each PDE/PTE only once while operating on it. Otherwise, it
is possible to have the relevant PTE change underneath us. For example,
after checking the valid bit, but before reading the physical address.

Convert the loads to atomics, and add some validation around the
physical addresses, to ensure that we do not try to dump a non-existent
or non-canonical physical address.

Similarly, don't read kernel_vm_end more than once, on the off chance
that pmap_growkernel() is called between the two page table walks.

Reviewed by:	kib, markj
MFC after:	2 weeks
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D31990
2021-11-19 15:05:52 -04:00
Mitchell Horne
1adebe3cd6 minidump: Parameterize minidumpsys()
The minidump code is written assuming that certain global state will not
change, and rightly so, since it executes from a kernel debugger
context. In order to support taking minidumps of a live system, we
should allow copies of relevant global state that is likely to change to
be passed as parameters to the minidumpsys() function.

This patch does the work of parameterizing this function, by adding a
struct minidumpstate argument. For now, this struct allows for copies of
the kernel message buffer, and the bitset that tracks which pages should
be dumped (vm_page_dump). Follow-up changes will actually make use of
these arguments.

Notably, dump_avail[] does not need a snapshot, since it is not expected
to change after system initialization.

The existing minidumpsys() definitions are renamed, and a thin MI
wrapper is added to kern_dump.c, which handles the construction of
the state struct. Thus, calling minidumpsys() remains as simple as
before.

Reviewed by:	kib, markj, jhb
Sponsored by:	Juniper Networks, Inc.
Sponsored by:	Klara, Inc.
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D31989
2021-11-19 15:05:52 -04:00
Gordon Bergling
8b11850f9d TWL: Fix a typo in a source code comment
- s/maxium/maximum/

MFC after:	3 days
2021-11-19 19:26:34 +01:00
Elyes HAOUAS
9097ac9af4 Fix typo on "Celsius"
"Celcius" --> "Celsius"

Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Pull Request: https://github.com/freebsd/freebsd-src/pull/551/files
2021-11-18 23:05:32 -07:00
Kristof Provost
4e85b64890 Add a COMPAT_FREEBSD13 kernel option
Use it wherever COMPAT_FREEBSD11 is currently specified.

Reviewed by:	jhb (previous version)
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D33005
2021-11-17 03:08:40 +01:00
Warner Losh
7e3c9ec906 tcp: better congestion control defaults
Define CC_NEWRENO in all the appropriate DEFAULTS and std.* config
files. It's the default congestion control algorithm.  Add code to cc.c
so that CC_DEFAULT is "newreno" if it's not overriden in the config
file.

Sponsored by: Netflix
Fixes: b8d60729de ("tcp: Congestion control cleanup.")
Revired by: manu, hselasky, jhb, glebius, tuexen
Differential Revision:	https://reviews.freebsd.org/D32964
2021-11-12 12:16:11 -07:00
Randall Stewart
b8d60729de tcp: Congestion control cleanup.
NOTE: HEADS UP read the note below if your kernel config is not including GENERIC!!

This patch does a bit of cleanup on TCP congestion control modules. There were some rather
interesting surprises that one could get i.e. where you use a socket option to change
from one CC (say cc_cubic) to another CC (say cc_vegas) and you could in theory get
a memory failure and end up on cc_newreno. This is not what one would expect. The
new code fixes this by requiring a cc_data_sz() function so we can malloc with M_WAITOK
and pass in to the init function preallocated memory. The CC init is expected in this
case *not* to fail but if it does and a module does break the
"no fail with memory given" contract we do fall back to the CC that was in place at the time.

This also fixes up a set of common newreno utilities that can be shared amongst other
CC modules instead of the other CC modules reaching into newreno and executing
what they think is a "common and understood" function. Lets put these functions in
cc.c and that way we have a common place that is easily findable by future developers or
bug fixers. This also allows newreno to evolve and grow support for its features i.e. ABE
and HYSTART++ without having to dance through hoops for other CC modules, instead
both newreno and the other modules just call into the common functions if they desire
that behavior or roll there own if that makes more sense.

Note: This commit changes the kernel configuration!! If you are not using GENERIC in
some form you must add a CC module option (one of CC_NEWRENO, CC_VEGAS, CC_CUBIC,
CC_CDG, CC_CHD, CC_DCTCP, CC_HTCP, CC_HD). You can have more than one defined
as well if you desire. Note that if you create a kernel configuration that does not
define a congestion control module and includes INET or INET6 the kernel compile will
break. Also you need to define a default, generic adds 'options CC_DEFAULT=\"newreno\"
but you can specify any string that represents the name of the CC module (same names
that show up in the CC module list under net.inet.tcp.cc). If you fail to add the
options CC_DEFAULT in your kernel configuration the kernel build will also break.

Reviewed by: Michael Tuexen
Sponsored by: Netflix Inc.
RELNOTES:YES
Differential Revision: https://reviews.freebsd.org/D32693
2021-11-11 06:28:18 -05:00