This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.
EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).
As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions. The remainder of the patch addresses
adding appropriate includes to fix those files.
LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).
No functional change (intended). Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.
By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap. The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.
There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.
copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline. If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.
The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done. The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging. I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.
Tested by: pho
Discussed with: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D14633
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Initially, only tag files that use BSD 4-Clause "Original" license.
RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133
functions and stop attaching of dcons(4) and dcons_crom(4) if
they indicate failure. This fixes a panic seen on sparc64 machines
with no free physical memory in the requested 32-bit region but
still doesn't make dcons(4)/dcons_crom(4) these work. I think
the latter can be fixed by simply specifying ~0UL as the upper
limit for contigmalloc(9) and letting the bounce pages and the
IOMMU respectively handle limitations of the DMA engine. I didn't
want to change that without the consensus of simokawa@ though,
who unfortunately didn't reply so far.
MFC after: 1 week
and output, set BUS_DMA_COHERENT when creating the DMA map used for
loading the buffer. As a side-effect this solves locking issues on
sparc64 when dcons(4) calls bus_dmamap_sync(9) while in an interrupt
filter, which are executed in a critical section, and iommu(4) has
to use a sleep lock when taking advantage of the streaming buffer.
Reported and tested by: kensmith
Approved by: simokawa
A change to dconschat(8) will follow so that it can bomb
this address over FireWire to reset a wedged system.
Though this method is just a hack and far from perfection,
it should be useful if you don't want to go machine room
just to reset or to power-cycle a machine without
remote-managed power supply. And much better than doing:
# fwcontrol -m target-eui64
# dd if=/dev/zero of=/dev/fwmem0.2 bs=1m
Now, it's safe to call the fwohci interrupt(polling) routine while ddb/gdb
is active. After this change, a dcons connnection over FireWire can survive
bus resets even in kernel debugger.
This means that it is not too late to plug a FireWire cable after a panic
to investigate the problem.
Actually there is a small window(between a jump to kernel from loader and
initialization of dcons_crom) in which no one can take care of a bus reset.
Except that window, firewire console should keep working
from loader to reboot even with a panic and a bus reset.
(as far as you enable LOADER_FIREWIRE_SUPPORT)
- Implement dcons_ischar() and dcons_load_buffer().
- If loader passed a dcons buffer address, keep using it.
(We still need a patch to cheat memory management system.)
dcons(4): very simple console and gdb port driver
dcons_crom(4): FireWire attachment
dconschat(8): User interface to dcons
Tested with: i386, i386-PAE, and sparc64.
