names. I.e., everything related to pwm now goes in /dev/pwm. This will
make it easier for userland tools to turn an unqualified name into a fully
qualified pathname, whether it's the base pwmcX.Y name or a label name.
At a basic level, remove assumptions about the underlying algorithm (such as
output block size and reseeding requirements) from the algorithm-independent
logic in randomdev.c. Chacha20 does not have many of the restrictions that
AES-ICM does as a PRF (Pseudo-Random Function), because it has a cipher
block size of 512 bits. The motivation is that by generalizing the API,
Chacha is not penalized by the limitations of AES.
In READ_RANDOM_UIO, first attempt to NOWAIT allocate a large enough buffer
for the entire user request, or the maximal input we'll accept between
signal checking, whichever is smaller. The idea is that the implementation
of any randomdev algorithm is then free to divide up large requests in
whatever fashion it sees fit.
As part of this, two responsibilities from the "algorithm-generic" randomdev
code are pushed down into the Fortuna ra_read implementation (and any other
future or out-of-tree ra_read implementations):
1. If an algorithm needs to rekey every N bytes, it is responsible for
handling that in ra_read(). (I.e., Fortuna's 1MB rekey interval for AES
block generation.)
2. If an algorithm uses a block cipher that doesn't tolerate partial-block
requests (again, e.g., AES), it is also responsible for handling that in
ra_read().
Several APIs are changed from u_int buffer length to the more canonical
size_t. Several APIs are changed from taking a blockcount to a bytecount,
to permit PRFs like Chacha20 to directly generate quantities of output that
are not multiples of RANDOM_BLOCKSIZE (AES block size).
The Fortuna algorithm is changed to NOT rekey every 1MiB when in Chacha20
mode (kern.random.use_chacha20_cipher="1"). This is explicitly supported by
the math in FS&K §9.4 (Ferguson, Schneier, and Kohno; "Cryptography
Engineering"), as well as by their conclusion: "If we had a block cipher
with a 256-bit [or greater] block size, then the collisions would not
have been an issue at all."
For now, continue to break up reads into PAGE_SIZE chunks, as they were
before. So, no functional change, mostly.
Reviewed by: markm
Approved by: secteam(delphij)
Differential Revision: https://reviews.freebsd.org/D20312
Add some basic regression tests to verify behavior of both uint128
implementations at typical boundary conditions, to run on all architectures.
Test uint128 increment behavior of Chacha in keystream mode, as used by
'kern.random.use_chacha20_cipher=1' (r344913) to verify assumptions at edge
cases. These assumptions are critical to the safety of using Chacha as a
PRF in Fortuna (as implemented).
(Chacha's use in arc4random is safe regardless of these tests, as it is
limited to far less than 4 billion blocks of output in that API.)
Reviewed by: markm
Approved by: secteam(gordon)
Differential Revision: https://reviews.freebsd.org/D20392
Implement wiring changes on superpage mappings. Previously, a superpage
mapping was unconditionally demoted by pmap_unwire(), even if the wiring
change applied to the entire superpage mapping.
Rewrite a comment to use the arm64 names for bits in a page table entry.
Previously, the bits were referred to by their x86 names.
Use atomic_"op"_64() instead of atomic_"op"_long() to update a page table
entry in order to match the prevailing style in this file.
MFC after: 10 days
Previously, there was a pwmc instance for each instance of pwm hardware
regardless of how many pwm channels that hardware supported. Now there
will be a pwmc instance for each channel when the hardware supports
multiple channels. With a separate instance for each channel, we can have
"named channels" in userland by making devfs alias entries in /dev/pwm.
These changes add support for ivars to pwmbus, and use an ivar to track the
channel number for each child. It also adds support for hinted children.
In pwmc, the driver checks for a label hint, and if present, it's used to
create an alias for the cdev in /dev/pwm. It's not anticipated that hints
will be heavily used, but it's easy to do and allows quick ad-hoc creation
of named channels from userland by using kenv to create hint.pwmc.N.label=
hints. Upcoming changes will add FDT support, and most labels will
probably be specified that way.
Implement protection changes on superpage mappings. Previously, a superpage
mapping was unconditionally demoted by pmap_protect(), even if the
protection change applied to the entire superpage mapping.
Precompute the bit mask describing the protection changes rather than
recomputing it for every page table entry that is changed.
Skip page table entries that already have the requested protection changes
in place.
Reviewed by: andrew, kib
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D20657
is nothing left in the file that related to pwmbus at all. It just contains
prototypes for the functions implemented in dev/pwm.ofw_pwm.c, so name it
accordingly and fix the include protect wrappers to match.
A new pwmbus.h will be coming along in a future commit.
The natural place to look for them based on how other SoCs are organized
would be sys/modules/ti, but that's already taken. Drop a clue into
modules/ti/Makefile directing people to modules/arm_ti if they're looking
for ARM modules.
The pwm and pwmbus interfaces were nearly identical, this merges them into a
single pwmbus interface. The pwmbus driver now implements the pwmbus
interface by simply passing all calls through to its parent (the hardware
driver). The channel_count method moves from pwm to pwmbus, and the
get_bus method is deleted (just no longer needed).
The net effect is that the interface for doing pwm stuff is now the same
regardless of whether you're a child of pwmbus, or some random driver
elsewhere in the hierarchy that is bypassing the pwmbus layer and is talking
directly to the hardware driver via cross-hierarchy connections established
using fdt data.
The pwmc driver is now a child of pwmbus, instead of being its sibling
(that's why the get_bus method is no longer needed; pwmc now gets the
device_t of the bus using device_get_parent()).
pollution that was cleaned up recently, and this file got missed in the
cleanup because it's not attached to the build unless you specifically
request this device in a custom kernel config.
ioctl definitions and related datatypes that allow userland control of pwm
hardware via the pwmc device. The new name and location better reflects its
assocation with a single device driver.
it only called vm_page_dirty() on the first of the superpage's constituent
4KB pages. This revision corrects that error, calling vm_page_dirty() on
all of superpage's constituent 4KB pages.
MFC after: 3 days
driver is compiled into the kernel but pwmbus will be loaded as a module
when needed (and because of that, pwmbus_attach_bus() is going away in
the near future). Instead, just directly do what that function did:
register the fdt xfef handle, and attach the pwmbus.
resources if they got allocated (because detach() gets called from attach()
to handle various failures), and delete the pwmbus child if it got created.
structs with placeholders (in the latter case, IFLIB_MAX_TX_BYTES
etc. are also only ever used for these write-only members if at all,
so both these macros and members can just go). Using these spares
may render it possible to merge certain iflib(9) fixes to stable/12.
Otherwise, changes extending struct if_irq or struct if_shared_ctx
in any way would break KBI as instances of these are allocated by
the driver front-ends (by contrast, struct if_pkt_info as well as
struct if_softc_ctx instances are provided by iflib(9) and, thus,
may grow at least at the end without breaking KBI).
- Make the pvi_name in struct pci_vendor_info const char * as device
identifiers in hardware lookup tables aren't to be expected to ever
change at runtime.
- Similarly, make the pci_vendor_info_t of struct if_shared_ctx which
is used to point to the struct pci_vendor_info arrays provided by
the driver front-ends const.
- Remove the ETH_ADDR_LEN macro from iflib.h; this was duplicating
ETHER_ADDR_LEN of <net/ethernet.h> with iflib(9) actually only
consuming the latter macro.
- Make the name argument of iflib_io_tqg_attach(9) const, matching
the taskqgroup_attach_cpu(9) this function wraps as well as e. g.
iflib_config_gtask_init(9).
- Remove the orphaned iflib_qset_lock_get() prototype.
- Remove some extraneous empty lines.
the lost information in new comments.
Reported by: alc
Reviewed by: alc
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D20632
I just happenned to have 3rd party code using 'var' as the output variable
which drew my attention to this. variables defined inside macros should be
prefixed to avoid getting shadowed varable wanrings from clang.
For busy ARC situation when arc_size close to arc_c is desired. But
then it is quite likely that aggsum_compare(&arc_size, arc_c) will need
to flush per-CPU buckets to find exact comparison result. Doing that
often in a hot path penalizes whole idea of aggsum usage there, since it
replaces few simple atomic additions with dozens of lock acquisitions.
Replacing aggsum_compare() with aggsum_upper_bound() in code increasing
arc_p when ARC is growing (arc_size < arc_c) according to PMC profiles
allows to save ~5% of CPU time in aggsum code during sequential write
to 12 ZVOLs with 16KB block size on large dual-socket system.
I suppose there some minor arc_p behavior change due to lower precision
of the new code, but I don't think it is a big deal, since it should
affect only very small window in time (aggsum buckets are flushed every
second) and in ARC size (buckets are limited to 10 average ARC blocks
per CPU).
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
It is too generous to collect in production debug traces that can only
be read with kernel debugger. Illumos includes special code in their
mdb debugger to read it, we don't.
MFC after: 1 week
Sponsored by: iXsystems, Inc.
not performed directly by the pmap. Instead, they are performed by
vm_page_free_pages_toq(). (This is the same approach that we use on x86.)
Reviewed by: kib, markj
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D20627
iterate over consecutive vm_map entries, and that can easily just
'remember' the prev value instead of looking it up.
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D20628
Normally td_runtime is updated on context switch, but there are some kernel
threads that due to high absolute priority may run for many seconds without
context switches (yes, that is bad, but that is true), which means their
td_runtime was not updated all that time, that made them invisible for top
other then as some general CPU usage.
MFC after: 1 week
Sponsored by: iXsystems, Inc.
