An i2c bus can be divided into segments which can be selectively connected
and disconnected from the main bus. This is usually done to enable using
multiple slave devices having the same address, by isolating the devices
onto separate bus segments, only one of which is connected to the main bus
at once.
There are several types of i2c bus muxes, which break down into two general
categories...
- Muxes which are themselves i2c slaves. These devices respond to i2c
commands on their upstream bus, and based on those commands, connect
various downstream buses to the upstream. In newbus terms, they are both
a child of an iicbus and the parent of one or more iicbus instances.
- Muxes which are not i2c devices themselves. Such devices are part of the
i2c bus electrically, but in newbus terms their parent is some other
bus. The association with the upstream bus must be established by
separate metadata (such as FDT data).
In both cases, the mux driver has one or more iicbus child instances
representing the downstream buses. The mux driver implements the iicbus_if
interface, as if it were an iichb host bridge/i2c controller driver. It
services the IO requests sent to it by forwarding them to the iicbus
instance representing the upstream bus, after electrically connecting the
upstream bus to the downstream bus that hosts the i2c slave device which
made the IO request.
The net effect is automatic mux switching which is transparent to slaves on
the downstream buses. They just do i2c IO they way they normally do, and the
bus is electrically connected for the duration of the IO and then idled when
it is complete.
The existing iicbus_if callback() method is enhanced so that the parameter
passed to it can be a struct which contains a device_t for the requesting
bus and slave devices. This change is done by adding a flag that indicates
the extra values are present, and making the flags field the first field of
a new args struct. If the flag is set, the iichb or mux driver can recast
the pointer-to-flags into a pointer-to-struct and access the extra
fields. Thus abi compatibility with older drivers is retained (but a mux
cannot exist on the bus with the older iicbus driver in use.)
A new set of core support routines exists in iicbus.c. This code will help
implement mux drivers for any type of mux hardware by supplying all the
boilerplate code that forwards IO requests upstream. It also has code for
parsing metadata and instantiating the child iicbus instances based on it.
Two new hardware mux drivers are added. The ltc430x driver supports the
LTC4305/4306 mux chips which are controlled via i2c commands. The
iic_gpiomux driver supports any mux hardware which is controlled by
manipulating the state of one or more gpio pins. Test Plan
Tested locally using a variety of mux'd bus configurations involving both
ltc4305 and a homebrew gpio-controlled mux. Tested configurations included
cascaded muxes (unlikely in the real world, but useful to prove that 'it all
just works' in terms of the automatic switching and upstream forwarding of
IO requests).
This is needed when the driver is compiled into the kernel.
When compiled as a module this will be called from another
code path as we also depend on ofw_spibus.
MFC after: 1 week
- Drop mention of _LP64. FreeBSD's source generally uses __LP64__
instead of _LP64, and the relevant macros are better covered in the
"Predefined Macros" section.
- Fix a noun/verb disagreement.
Reviewed by: emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22975
SCTP_PEER_ADDR_PARAMS socket option. The code in the stack assumes
sane values for the MTU.
This issue was found by running an instance of syzkaller.
MFC after: 1 week
command line option. Thanks to the removal of unnecessary information and
the organization into columns, this helps the output be more legible on
both 80 column displays and non-80 column displays. imp@ provided the
idea on this.
Since rS330365, there has been no particular reason for libofw to be in a
subdirectory of ofw. Move libofw up a level to make it fit in better with
the other top level libraries.
Also add a LIBOFWSRC to stand/defs.mk to match what all the other
libraries are doing.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D23000
TARGET=arm now defaults to TARGET_ARCH=armv7
TARGET_ARCH=arm is no longer valid.
Bump __FreeBSD_version to 1300073
Tested with make universe. Any stale LINT-V5 config files remaining in the tree
will fail the universe build. However, LINT-V5 was removed in r355119.
This retirement has been planned since last summer. The armv5 port is fragile:
it works OK for some peeople, and fails badly for others. There's a number of
subtle bugs in busdma, pmap and other MD parts of thee system that present
themselves under load or in unusual circumstances (like fsck after a
crash). stable/8, branched 10 years ago, was the last reliable release. Since
the support burden is larger then the benefit, the consensus view is armv5
should be removed from the tree.
Discussed with: arm@ mailing list and arm developer community.
r23081 introduced kern.dummy oid as a semi ABI compat for kern.maxsockbuf
that was moved to a new namespace. It never functioned as an alias of any
kind and was just returning 0 unconditionally, hence it was probably
provided to keep some 3rd party programmes happy about sysctl(3) not
reporting an error because of non-existing oid.
After nearly 23 years it seems reasonable to just hide it from sysctl(8)
list not to cause unnecessary confusion as for its purpose.
Reported by: Antranig Vartanian <antranigv@freebsd.am>
Reviewed by: kib (mentor)
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D22982
[X86] Add X87 FCMOV support to X86FlagsCopyLowering.
Fixes PR44396
Merge commit 86f48999f from llvm git (by Craig Topper):
[X86] Fix typo in getCMovOpcode.
The 64-bit HasMemoryOperand line was using CMOV32rm instead of
CMOV64rm. Not sure how to test this. We have no test coverage that
passes true for HasMemoryOperand.
This fixes 'Assertion failed: (MI.findRegisterDefOperand(X86::EFLAGS) &&
"Expected a def of EFLAGS for this instruction!"), function
runOnMachineFunction' when compiling the misc/gpsim port for i386.
Reported by: yuri
Upstream PR: https://bugs.llvm.org/show_bug.cgi?id=44396
MFC after: 1 week
Highlights:
- Use MAX() for maxsock raising; small readability improvement IMO
- malloc(3) + memset(3) -> calloc(3) where appropriate
- stop casting the return value of malloc(3)
- mallloc(3) -> reallocarray(3) where appropriate
A future change may enter capability mode when forking for some of the
built-in handlers.
If getcwd() failed earlier on but later succeeded in the pwd builtin,
there was no INTOFF protection between calling savestr() and storing its
result.
It is quite rare for getcwd() to fail, and rarer for it to succeed later in
the same directory.
Found via code inspection for changing ckmalloc() and similar to assert
INTOFF protection instead of applying it directly (which protects against
corrupting malloc's internal state but allows memory leaks or double frees).
MFC after: 1 week
This utility was initially written for FAT12/16, which were inherently
small. When FAT32 support was added, the old data structure and
algorithms remain used with minimal changes.
With growing size of FAT32 media, the current data structure that
requires 4 32-bit variables per each FAT32 table entry would consume up
to 4 GiB of RAM, which can be too big for systems with limited RAM
available.
Address this by taking a different approach of validating the FAT.
The FAT is essentially a set of linked lists of chains that was
referenced by directory entries, and the checker needs to make sure that
the linked chains of clusters do not have cross-linked chains, and every
chain were referenced by one and only one directory entry. Instead of
keeping track of the chain's 'head' cluster number, the size of the
chain, the used status of the chain and the "next" pointer which is
content of the FAT table, we create accessors for the FAT table data
for the "next" pointer, and keep only one bit to indicate if the
current cluster is a 'head' node of a cluster chain, in a bitmap.
We further overhaul the FAT checker to find out the possible head nodes
by excluding ones that are not (in other words, nodes that have some
other nodes claiming them as the next node) instead of marking the head
nodes for each node on the chain. This approach greatly reduced the
complexiety of computation from O(N^2) worst case, to an O(N) scan for
worst case. The file (cluster chain) length is not useful for the FAT
checker, so don't bother to calculate them in the FAT checker and
instead leave the task to the directory structure check, at which point
we would have non-crossed cluster chains, and we are guaranteed that
each cluster will be visited for at most one time.
When checking the directory structures, we use the head node indicator
to as the visited (used) flag: every cluster chain can only be
referenced by one directory entry, so we clear them when calculating
the length of the chain, and we can immediately tell if there are
anomalies in the directory entry.
As a result, the required RAM size is now 1 bit per each entry of
the FAT table, plus memory needed to hold the FAT table in memory,
instead of 16 bytes (=128 bits) per each entry. For FAT12 and FAT16,
we will load the whole FAT table into memory as they are smaller than
128KiB, and for FAT32, we first attempt to mmap() it into memory, and
when that fails, we would fall back to a simple LRU cache of 4 MiB of
RAM.
sbin/fsck_msdosfs/boot.c:
- Added additional sanity checks for valid FAT32/FAT16/FAT12 cluster
number.
- FAT32: check if root directory starts with a valid cluster number,
moved from dir.c. There is no point to proceed if the filesystem
is already damaged beyond repair.
sbin/fsck_msdosfs/check.c:
- Combine phase 1 and phase 2, now that the readfat() is able to
detect cross chains.
sbin/fsck_msdosfs/dir.c:
- Refactor code to use FAT accessor instead of accessing the internal
representation of FAT table.
- Make use of the cluster chain head bitmap.
- Clarify and simplify directory entry check, remove unnecessary
checks that are would be done at a later time (for example, whether
the directory's second cluster is a valid one, which is examined
more throughly in a later checkchain() and does not prevent us
from proceeding further).
sbin/fsck_msdosfs/dosfs.h:
- Remove internal representation of FAT table, which is replaced by
the head bitmap that is opaque to other code.
- Added a special CLUST_DEAD cluster type to indicate errors.
sbin/fsck_msdosfs/ext.h:
- Added a flag that overrides mmap(2) setting. The corresponding
command line option, -M is intentionally undocumented as we do not
expect users to need it.
- Added accessors for FAT table and convert existing interface to use
it.
sbin/fsck_msdosfs/fat.c:
- Added head bitmap to represent whether a cluster is a head cluster.
- Converted FAT internal representation to accessors.
- Implemented a LRU cache for FAT32 when mmap(2) should not or can not
be used.
- _readfat: Attempt a mmap(2) and fall back to regular read for
non-FAT32 file systems; use the LRU cache for FAT32 and prepopulate
the cache with the first 4MiB of the entries.
- readfat: Added support of head bitmap and use the population scan to
detect bogus chains.
- clusterdiff: removed, FATs are copied from the checked copy via
writefat()/copyfat().
- checkchain: calculates the length of a cluster chain and make sure
that it ends with a valid EOF marker.
- clearchain: follow and clear a chain and maintain the free cluster
count.
- checklost: convert to use head bitmap. At the end of all other scans,
the remaining 'head' nodes are leaders of lost cluster chains.
sbin/fsck_msdosfs/fat.c:
- Added a new -M option which is intentionally undocumented, to disable
the use of mmap().
Reviewed by: kevlo
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D22965
This change is purely in the name of noise reduction from static analyzers
that want to complain that bzero(3) is obsolete in favor of memset(3).
With this, clang-analyze at least is now noise free. WARNS= 6 also appears
to have been OK for some time now, so drop the current setting and opt for
the default.
Currently, child pids are only tracked if maxchildren is specified. As a
consequence, without a maxchild limit we do not get a notice in syslog on
children aborting abnormally. This turns out to be a great debugging aide at
times.
Children are now tracked in a LIST; the management interface is decidedly
less painful when there's no upper bound on the number of entries we may
have at the cost of one small allocation per connection.
PR: 70335
The main point here is capturing the maxchild > 0 check. A future change to
inetd will start tracking all of the child pids so that it can give proper
and consistent notification of process exit/signalling.
The number is public and has no "entropy," but should be integrated quickly
on VM rewind events to avoid duplicate sequences.
Approved by: csprng(markm)
Differential Revision: https://reviews.freebsd.org/D22946
r356242 updated nfsstat.c to report that the "-M" and "-N" options were
being ignored. These options have never had any meaning for the new NFS
code (which is now the only NFS code).
This patch updates the man page to reflect this.
This is a content change.
entry in the vm_map, making invariants related to the max_free entry
field invalid. Move the clipping work into vm_map_entry_link, so that
linking is okay when the new entry clips a current entry, and the
vm_map doesn't have to be briefly corrupted. Change assertions and
conditions in SPLAY_{LEFT,RIGHT}_STEP since the max_free invariants
can now be trusted in all cases.
Tested by: pho
Reviewed by: alc
Differential Revision: https://reviews.freebsd.org/D22897
The "-M" and "-N" options for nfsstat were used by the old NFS code and
have never done anything for the new NFS code.
This patch replaces code that assigns values to variables that are never
used with printf()s noting the options are ignored.
This has the side effect that it gets rid of warnings w.r.t. these
variables being assigned but never used, that occur for some builds.
Noticed during integration of the NFSv4.2 code.
syscall is to query the CPU number and the NUMA domain the calling
thread is currently running on. The third argument is ignored.
It doesn't do anything regarding scheduling - it's literally
just a way to query the current state, without any guarantees
you won't get rescheduled an opcode later.
This unbreaks Java from CentOS 8
(java-11-openjdk-11.0.5.10-0.el8_0.x86_64).
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22972
This fixes deadlock between CARP and bridge. Bridge calls this function
taking CARP lock while holding bridge lock. Same time CARP tries to send
its announcements via the bridge while holding CARP lock.
Use of CARP_LOCK() here does not solve anything, since sc_addr is constant
while race on sc_state is harmless and use of the lock does not close it.
Reviewed by: glebius
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Amount of changes to the original code has been intentionally minimised
to ease diffing.
The changes are mostly mechanical, with the following exceptions:
* lltable handler is now called directly based of RTF_LLINFO flag presense.
* "report" logic for updating rtm in RTM_GET/RTM_DELETE has been simplified,
fixing several potential use-after-free cases in rt_addrinfo.
* llable asserts has been replaced with error-returning, preventing kernel
crashes when lltable gw af family is invalid (root required).
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22864
in the case where a packet not marked was received.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D19143
Implement support for the UART as found on the SiFive FU540. It should
also work on, but has not been tested with, the FU310.
Reviewed by: philip
Sponsored by: Axiado
There's no point in checking for absent CPUs if we're not going to do anything
about either the present or absent case. This loop can just be removed.
Reviewed by: philip
Sponsored by: Axiado
