kevans [Mon, 6 Jan 2020 18:15:55 +0000 (18:15 +0000)]
Update libssp paths in various Makefile.depend* files
I've been advised that the model that uses these are fairly resilient, but
we do know the proper path to use (or remove, in the case of ^/targets/...),
so go ahead and update them to reflect that.
jhb [Mon, 6 Jan 2020 18:02:02 +0000 (18:02 +0000)]
Simplify arguments to signal handlers on mips.
- Use ksi_addr directly as si_addr in the siginfo instead of the
'badvaddr' register.
- Remove a duplicate assignment of si_code.
- Use ksi_addr as the 4th argument to the old-style handler instead of
'badvaddr'.
jhb [Mon, 6 Jan 2020 17:34:17 +0000 (17:34 +0000)]
Only build kernels for enabled TARGET_ARCHes in make universe/tinderbox.
Previously, all of the kernels for a given TARGET were built if that
target was enabled. This was implemented by having each kernel built
via a universe_kernconf_<KERNEL> target that was depended on by a
universe_kernconfs target. However, this meant that if one did a
build with a limited set of TARGET_ARCH values for a given TARGET,
kernels could be built for which we hadn't built a world or toolchain.
For example, 'make TARGETS=mips TARGET_ARCHES_mips=mips64' would build
mips32 kernels.
Fix this by adding an extra layer of indirection in the kernel make
targets. universe_kernconf_<KERNEL> is now a dependency of a new
universe_kernconfs_<TARGET_ARCH>. universe_kernconfs in turn depends
on a list of universe_kernconfs_<target_arch> values, but only the
values enabled in TARGET_ARCHES_<TARGET>.
jeff [Mon, 6 Jan 2020 02:51:19 +0000 (02:51 +0000)]
Fix uma boot pages calculations on NUMA machines that also don't have
MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt
of zones while here. This was already correct because uz_cpu strongly
aligned the zone structure but the specified alignment did not match
reality and involved redundant defines.
In order to be able to merge r353026 bring back support for the old
cookie API for a transition period in 12.x releases (and possibly 13)
before the old API can be removed again entirely.
emaste [Sun, 5 Jan 2020 18:01:15 +0000 (18:01 +0000)]
src.opts.mk: disable BINUTILS_BOOTSTRAP on all mips* and sparc64
Extend r356379 to include 32-bit mips and sparc64. Using a decade-old
binutils linker with a contemporary compiler (either Clang or GCC) is
a combination unlikely to be used by anyone else, and it's not going
to be a good use of our time investigating and addressing any issues
that arise. Expect that all architectures newly migrated to external
GCC will also use external binutils.
emaste [Sun, 5 Jan 2020 16:59:24 +0000 (16:59 +0000)]
src.opts.mk: disable BINUTILS_BOOTSTRAP on mips64*
After GCC was disabled by default in r356367, mips and sparc64 started
relying external GCC. However, the in-tree Binutils ld 2.17.50 is not
compatible with GCC for some mips64 targets, so turn off
BINUTILS_BOOTSTRAP and rely on external binutils (linker) as well.
kevans [Sun, 5 Jan 2020 04:06:40 +0000 (04:06 +0000)]
shm: correct KPI mistake introduced around memfd_create
When file sealing and shm_open2 were introduced, we should have grown a new
kern_shm_open2 helper that did the brunt of the work with the new interface
while kern_shm_open remains the same. Instead, more complexity was
introduced to kern_shm_open to handle the additional features and consumers
had to keep changing in somewhat awkward ways, and a kern_shm_open2 was
added to wrap kern_shm_open.
Backpedal on this and correct the situation- kern_shm_open returns to the
interface it had prior to file sealing being introduced, and neither
function needs an initial_seals argument anymore as it's handled in
kern_shm_open2 based on the shmflags.
kevans [Sun, 5 Jan 2020 03:15:16 +0000 (03:15 +0000)]
shmfd/mmap: restrict maxprot with MAP_SHARED + F_SEAL_WRITE
If a write seal is set on a shared mapping, we must exclude VM_PROT_WRITE as
the fd is effectively read-only. This was discovered by running
devel/linux-ltp, which mmap's with acceptable protections specified then
attempts to raise to PROT_READ|PROT_WRITE with mprotect(2), which we
allowed.
emaste [Sun, 5 Jan 2020 02:47:56 +0000 (02:47 +0000)]
Do not build GCC 4.2.1 by default for any CPU architecture
By default set to NO:
GCC
GCC_BOOTSTRAP
GNUCXX
As described by imp@ on the freebsd-arch mailing list Aug 13, 2019 with
Subject: Gcc 4.2.1 to be removed before FreeBSD 13, a firm timeline
https://lists.freebsd.org/pipermail/freebsd-arch/2019-August/019674.html
Reviewed by: jhb, imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23026
kevans [Sat, 4 Jan 2020 23:39:58 +0000 (23:39 +0000)]
kern_mmap: add a variant that allows caller to inspect fp
Linux mmap rejects mmap() on a write-only file with EACCES.
linux_mmap_common currently does a fun dance to grab the fp associated with
the passed in fd, validates it, then drops the reference and calls into
kern_mmap(). Doing so is perhaps both fragile and premature; there's still
plenty of chance for the request to get rejected with a more appropriate
error, and it's prone to a race where the file we ultimately mmap has
changed after it drops its referenced.
This change alleviates the need to do this by providing a kern_mmap variant
that allows the caller to inspect the fp just before calling into the fileop
layer. The callback takes flags, prot, and maxprot as one could imagine
scenarios where any of these, in conjunction with the file itself, may
influence a caller's decision.
The file type check in the linux compat layer has been removed; EINVAL is
seemingly not an appropriate response to the file not being a vnode or
device. The fileop layer will reject the operation with ENODEV if it's not
supported, which more closely matches the common linux description of
mmap(2) return values.
If we discover that we're allowing an mmap() on a file type that Linux
normally wouldn't, we should restrict those explicitly.
kevans [Sat, 4 Jan 2020 22:05:00 +0000 (22:05 +0000)]
libssp: fix FORTIFY_SOURCE stub declarations
The LSB 4.1 that I referenced omitted the varargs, and I failed to catch it.
The __vsnprintf_chk error was from just downright misreading the page. GCC6
caught all of these, but I had only tested GCC4.2.
kevans [Sat, 4 Jan 2020 20:19:25 +0000 (20:19 +0000)]
Provide libssp based on libc
For libssp.so, rebuild stack_protector.c with FORTIFY_SOURCE stubs that just
abort built into it.
For libssp_nonshared.a, steal stack_protector_compat.c from
^/lib/libc/secure and massage it to maintain that __stack_chk_fail_local
is a hidden symbol.
libssp is now built unconditionally regardless of {WITH,WITHOUT}_SSP in the
build environment, and the gcclibs version has been disconnected from the
build in favor of this one.
PR: 242950 (exp-run)
Reviewed by: kib, emaste, pfg, Oliver Pinter (earlier version)
Also discussed with: kan
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22943
kevans [Sat, 4 Jan 2020 20:07:11 +0000 (20:07 +0000)]
ssp: knock out some trivial warnings that come up with WARNS=6
A future commit will rebuild this as part of libssp. The exact warnings are
fairly trivially fixed:
- No previous declaration for __stack_chk_guard
- idx is the wrong type, nitems yields a size_t
- Casting away volatile on the tmp_stack_chk_guard directly is a no-no.
alc [Sat, 4 Jan 2020 19:50:25 +0000 (19:50 +0000)]
When a copy-on-write fault occurs, pmap_enter() is called on to replace the
mapping to the old read-only page with a mapping to the new read-write page.
To destroy the old mapping, pmap_enter() must destroy its page table and PV
entries and invalidate its TLB entry. This change simply invalidates that
TLB entry a little earlier, specifically, on amd64 and arm64, before the PV
list lock is held.
jeff [Sat, 4 Jan 2020 19:29:25 +0000 (19:29 +0000)]
Fix an assertion introduced in r356348. On architectures without
UMA_MD_SMALL_ALLOC vmem has a more complicated startup sequence that
violated the new assert. Resolve this by rewriting the COLD asserts to
look at the per-cpu allocation counts for evidence of api activity.
jeff [Sat, 4 Jan 2020 18:48:13 +0000 (18:48 +0000)]
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names
more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and
UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending
on kernel configuration. API users need only specify one if they want to
override the default.
Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off
of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA
is.
jeff [Sat, 4 Jan 2020 07:56:28 +0000 (07:56 +0000)]
Sort cross-domain frees into per-domain buckets before inserting these
onto their respective bucket lists. This is a several order of magnitude
improvement in contention on the keg lock under heavy free traffic while
requiring only an additional bucket per-domain worth of memory.
jeff [Sat, 4 Jan 2020 03:30:08 +0000 (03:30 +0000)]
Use per-domain keg locks. This provides both a lock and separate space
accounting for each NUMA domain. Independent keg domain locks are important
with cross-domain frees. Hashed zones are non-numa and use a single keg
lock to protect the hash table.
jeff [Sat, 4 Jan 2020 03:15:34 +0000 (03:15 +0000)]
Use a separate lock for the zone and keg. This provides concurrency
between populating buckets from the slab layer and fetching full buckets
from the zone layer. Eliminate some nonsense locking patterns where
we lock to fetch a single variable.
jeff [Sat, 4 Jan 2020 03:04:46 +0000 (03:04 +0000)]
Use atomics for the zone limit and sleeper count. This relies on the
sleepq to serialize sleepers. This patch retains the existing sleep/wakeup
paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup
in one case but otherwise should be bug for bug compatible. In particular,
there are still various races surrounding adjusting the limit via sysctl
that are now documented.
jhb [Fri, 3 Jan 2020 23:31:38 +0000 (23:31 +0000)]
Set correct lib32 MACHINE_ARCH for mips64el*.
Use "mipsel" instead of "mips" as the 32-bit MACHINE_ARCH when
building lib32 for little-endian 64-bit MIPS targets. This fixes an
error where some objects were compiled as LE and others compiled as BE
causing a link error for rtld32.
dim [Fri, 3 Jan 2020 20:29:54 +0000 (20:29 +0000)]
Merge commit 189b7393d from llvm git (by John Baldwin):
[lld][RISCV] Use an e_flags of 0 if there are only binary input files.
Summary:
If none of the input files are ELF object files (for example, when
generating an object file from a single binary input file via "-b
binary"), use a fallback value for the ELF header flags instead of
crashing with an assertion failure.
dim [Fri, 3 Jan 2020 20:28:06 +0000 (20:28 +0000)]
Merge commit d7be3eab5 from llvm git (by LuÃs Marques):
[RISCV] Handle fcopysign(f32, f64) and fcopysign(f64, f32)
Summary: Adds tablegen patterns to explicitly handle fcopysign where
the magnitude and sign arguments have different types, due to the
sign value casts being removed the by DAGCombiner. Support for RV32IF
follows in a separate commit. Adds tests for all relevant scenarios
except RV32IF.
dim [Fri, 3 Jan 2020 20:19:17 +0000 (20:19 +0000)]
Merge commit c6b09bff5 from llvm git (by LuÃs Marques):
[RISCV] Fix wrong CFI directives
Summary: Removes CFI CFA directives that could incorrectly propagate
beyond the basic block they were inteded for. Specifically it removes
the epilogue CFI directives. See the branch_and_tail_call test for an
example of the issue. Should fix the stack unwinding issues caused by
the incorrect directives.
dim [Fri, 3 Jan 2020 20:11:40 +0000 (20:11 +0000)]
Merge commit da7b129b1 from llvm git (by James Clarke):
[RISCV] Don't force Local Exec TLS for non-PIC
Summary:
Forcing Local Exec TLS requires the use of copy relocations. Copy
relocations need special handling in the runtime linker when being
used against TLS symbols, which is present in glibc, but not in
FreeBSD nor musl, and so cannot be relied upon. Moreover, copy
relocations are a hack that embed the size of an object in the ABI
when it otherwise wouldn't be, and break protected symbols (which are
expected to be DSO local), whilst also wasting space, thus they
should be avoided whenever possible. As discussed in D70398, RISC-V
should move away from forcing Local Exec, and instead use Initial
Exec like other targets, with possible linker relaxation to follow.
The RISC-V GCC maintainers also intend to adopt this
more-conventional behaviour (see
https://github.com/riscv/riscv-elf-psabi-doc/issues/122).
The reason seems to be that in RISCVAsmBackend::shouldForceRelocation
we only consider the fragment but in RISCVMCExpr::evaluatePCRelLo we
consider the section. This usually works but there are cases where
the section may still be the same but the fragment may be another
one. In that case we end forcing a %pcrel_lo relocation without any
%pcrel_hi.
This patch makes RISCVAsmBackend::shouldForceRelocation use the
section, if any, to determine if the relocation must be forced or
not.
kevans [Fri, 3 Jan 2020 19:59:42 +0000 (19:59 +0000)]
mips: csu: fix compilation w/ LLVM
GCC issues the warning, but with LLVM it is fatal- no matching .cprestore
with .cpload. Reserve some place on the stack and and add the proper
.cprestore to pair it with.
nop added in the !o32 branch to fill out delay slot instruction, just in
case.
emaste [Fri, 3 Jan 2020 16:28:10 +0000 (16:28 +0000)]
src.opts.mk: switch LLD_BOOTSTRAP and LLD_IS_LD to opt-out
More MACHINE_CPUARCH/MACHINE_ARCH cases enable these options than
disable them, and several of them have work in progress to switch over.
Thus, invert the sense of the test and list cases not using LLD as the
exceptions.
emaste [Fri, 3 Jan 2020 16:06:41 +0000 (16:06 +0000)]
src.opts.mk: simplify after arm/arm retirement
There were a few special cases for arm v5, such as disabling LLDB due to
the lack of 64-bit atomic operations. Now that arm has been retired (as
of r356263) we can simplify the options logic somewhat.
delphij [Fri, 3 Jan 2020 00:31:48 +0000 (00:31 +0000)]
Reduce memory footprint of fsck_msdosfs.
This is a re-apply r356249 with changes to make GCC happy.
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().
erj [Thu, 2 Jan 2020 23:35:06 +0000 (23:35 +0000)]
iflib: Prevent watchdog from resetting idle queues
While changing link state in iflib_link_state_change(), queues are
marked as IFLIB_QUEUE_IDLE to disable watchdog. Currently, iflib_timer()
watchdog does not check for previous queue status before marking it as
IFLIB_QUEUE_HUNG.
This patch adds check of queue status before marking it as hung.
Signed-off-by: Piotr Pietruszewski <piotr.pietruszewski@intel.com>
PR: 239240
Submitted by: Piotr Pietruszewski <piotr.pietruszewski@intel.com>
Reported by: ultima@
Reviewed by: gallatin@, erj@
MFC after: 3 days
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21712
bdragon [Thu, 2 Jan 2020 23:20:37 +0000 (23:20 +0000)]
[PowerPC] [MIPS] Implement 32-bit kernel emulation of atomic64 operations
This is a lock-based emulation of 64-bit atomics for kernel use, split off
from an earlier patch by jhibbits.
This is needed to unblock future improvements that reduce the need for
locking on 64-bit platforms by using atomic updates.
The implementation allows for future integration with userland atomic64,
but as that implies going through sysarch for every use, the current
status quo of userland doing its own locking may be for the best.
kevans [Thu, 2 Jan 2020 23:07:45 +0000 (23:07 +0000)]
capsicum_helpers: split stream cap bits out of caph_limit_stream()
The goal here is to make it so applications can take the rights one would
normally get by calling caph_limit_stream() on a descriptor and build on
them as needed.
The tentatively planned use-case is an application that takes a socket and
hooks it up to std{err,out,in} for a fork()d child. It may be feasible to
apply limitations to such descriptors as long as it's a superset of those
normally applied to stdio.
kevans [Thu, 2 Jan 2020 23:00:52 +0000 (23:00 +0000)]
iicoc: limit fdt attachment to EXT_RESOURCES platforms
The fdt attachment for this heavily relies on extres for clk work. This
unbreaks the build for mips XLPN32/XLP, which have pci/fdt but no need for
this fdt attachment.
kevans [Thu, 2 Jan 2020 22:52:31 +0000 (22:52 +0000)]
sys/dev/cfi: include sys/types.h as well
This will soon be a dependency for machine/atomic.h on mips with the
introduction of 64-bit atomics; the scope here is pretty narrow, so throw it
here in the header just before systm.h, which includes machine/atomic.h
kib [Thu, 2 Jan 2020 22:48:08 +0000 (22:48 +0000)]
Fix AT_EXECPATH for direct exec mode.
When activated in direct exec mode, kernel-provided AT_EXECPATH points
to the interpreter. We need to recalculate auxv to point to the
string with the path to the executable which is actually executed.
The somewhat problematic case is when the executable path is relative
and either $PATH use is not enabled or it contains '/' so $PATH search
is not performed. In this case resulting AT_EXECPATH is relative, I
might fix this later.
Reported and reviewed by: rstone
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22894
markj [Thu, 2 Jan 2020 19:26:04 +0000 (19:26 +0000)]
Clear queue operation flags when migrating a page to another queue.
The page daemon loops may move pages back to the active queue if
references are detected. In this case we must take care to clear
existing queue operation flags. In particular, PGA_REQUEUE_HEAD may be
set, and that flag is only valid if the page belongs to the inactive
queue.
Also fix a bug in the active queue scan where we were updating "old"
instead of "new". This would only have been hit in rare cases where the
page moved out of the active queue after the beginning of the scan.
kevans [Thu, 2 Jan 2020 18:46:33 +0000 (18:46 +0000)]
libbe(3): promote dependent clones when destroying an environment
When removing a boot environment iterate over the dependents and process the
snapshots by grabbing any clones. Promote the clones we found and then
remove the target environment.
This fixes the ability to destroy a boot environment when it has been used
to spawn one or more other boot environments.
ian [Thu, 2 Jan 2020 17:51:49 +0000 (17:51 +0000)]
Add support for i2c bus mux hardware.
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).
manu [Thu, 2 Jan 2020 17:39:21 +0000 (17:39 +0000)]
arm: allwinner: aw_spi: Call bus_generic_attach
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.