Previously, a page fault taken during copyin/out and related functions
would run the entire fault handler while permitting direct access to
user addresses. This could also leak across context switches (e.g. if
the page fault handler was preempted by an interrupt or slept for disk
I/O).
To fix, clear SUM in assembly after saving the original version of
SSTATUS in the supervisor mode trapframe.
Reviewed by: mhorne, jrtc27
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D29763
Use the new kdb variants. Print more specific error messages.
Reviewed by: jhb, markj
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D29156
This basically mirrors what already exists in ddb, but provides a
slightly improved interface. It allows the caller to specify the
watchpoint access type, and returns more specific error codes to
differentiate failure cases.
This will be used to support hardware watchpoints in gdb(4).
Stubs are provided for architectures lacking hardware watchpoint logic
(mips, powerpc, riscv), while other architectures are added individually
in follow-up commits.
Reviewed by: jhb, kib, markj
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D29155
This change serves two purposes.
First, we take advantage of the compiler provided endian definitions to
eliminate some long-standing duplication between the different versions
of this header. __BYTE_ORDER__ has been defined since GCC 4.6, so there
is no need to rely on platform defaults or e.g. __MIPSEB__ to determine
endianness. A new common sub-header is added, but there should be no
changes to the visibility of these definitions.
Second, this eliminates the hand-rolled __bswapNN() routines, again in
favor of the compiler builtins. This was done already for x86 in
e6ff6154d2. The benefit here is that we no longer have to maintain our
own implementations on each arch, and can instead rely on the compiler
to emit appropriate instructions or libcalls, as available. This should
result in equivalent or better code generation. Notably 32-bit arm will
start using the `rev` instruction for these routines, which is available
on armv6+.
PR: 236920
Reviewed by: arichardson, imp
Tested by: bdragon (BE powerpc)
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D29012
e4b8deb222 removed the last in-tree uses of PCPU_INC(). Its
potential benefit is also practically nonexistent. Non-x86
platforms already implement it as PCPU_ADD(..., 1), and according
to [0] there are no recent x86 processors for which the 'inc'
instruction provides a performance benefit over the equivalent
memory-operand form of the 'add' instruction. The only remaining
benefit of 'inc' is smaller instruction size, which in this case
is inconsequential given the limited number of per-CPU data consumers.
[0]: https://www.agner.org/optimize/instruction_tables.pdf
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D29308
This appears to be a copy-and-paste error that has simply been
overlooked. The tree contains only two calls to any of the affected
variants, but recent additions to the test suite started exercising the
call to atomic_clear_rel_int() in ng_leave_write(), reliably causing
panics.
Apparently, the issue was inherited from the arm64 atomic header. That
instance was addressed in c90baf6817, but the fix did not make its way
to RISC-V.
Note that the particular test case ng_macfilter_test:main still appears
to fail on this platform, but this change reduces the panic to a
timeout.
PR: 253237
Reported by: Jenkins, arichardson
Reviewed by: kp, arichardson
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D29064
This macro returns true if a provided virtual address is contained
in the kernel's clean submap.
In CHERI kernels, the buffer cache and transient I/O map are allocated
as separate regions. Abstracting this check reduces the diff relative
to FreeBSD. It is perhaps slightly more readable as well.
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D28710
The System Reset extension provides functions to shutdown or reboot the
system via SBI firmware. This newly defined extension supersedes the
functionality of the legacy shutdown extension.
Update the SBI code to use the new System Reset extension when
available, and fall back to the legacy one.
Reviewed By: kp, jhb
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D28226
This setting limits the amount of memory that can be allocated to UMA.
On systems with a direct map and ample KVA, however, there is no reason
for VM_KMEM_SIZE_SCALE to be larger than 1. This appears to have been
inherited from the 32-bit ARM platform definitions.
Also remove VM_KMEM_SIZE_MIN, which is not needed when
VM_KMEM_SIZE_SCALE is defined to be 1.[*]
Reviewed by: alc, kp, kib
Reported by: alc [*]
Submitted by: Klara, Inc.
Sponsored by: Ampere Computing
Differential Revision: https://reviews.freebsd.org/D28225
This is the superset of the nooptions found in the -DEBUG kernels.
Reviewed by: emaste, manu
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D28152
The purpose of this KASSERT is to ensure that we do not run out of space
in the early devmap. However, the devmap grew beyond its initial size of
2MB in r336519, and this assertion did not grow with it.
A devmap mapping of a 1080p framebuffer requires 1920x1080 bytes, or
1.977 MB, so it is just barely able to fit without triggering the
assertion, provided no other devices are mapped before it. With the
addition of `options GDB` in GENERIC by bbfa199cbc, the uart is now
mapped for the purposes of a debug port, before mapping the framebuffer.
The presence of both these conditions pushes the selected virtual
address just below the threshold, triggering the assertion.
To fix this, use the correct size of the devmap, defined by
PMAP_MAPDEV_EARLY_SIZE. Since this code is shared with RISC-V, define
it for that platform as well (although it is a different size).
PR: 25241
Reported by: gbe
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Ensure that we don't end up with a superpage in the vm_page_t's pv list.
This may help with debugging the panic reported in PR 250866, in which
l3 in pmap_remove_write() was found to be NULL. Adding a KASSERT to this
function will help narrow down the cause of this panic the next time it
occurs.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D28109
Add 64-bit address support to Cadence CGEM Ethernet driver for use in
other SoCs such as the Zynq UltraScale+ and SiFive HighFive Unleashed.
Reviewed by: philip, 0mp (manpages)
Differential Revision: https://reviews.freebsd.org/D24304
Add an additional set of braces to clarify intention. The '&' operator
has a higher precedence than '|', but the reader may not always remember
this. No functional change.
This sysctl node can generate very verbose output, so don't trigger it
for sysctl -a or sysctl vm.pmap.
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D27504
These implementation IDs are defined in the SBI spec, so we should print
their name if detected.
Submitted by: Danjel Qyteza <danq1222@gmail.com>
Reviewed by: jhb, kp
Differential Revision: https://reviews.freebsd.org/D27660
Ability to load-balance traffic over multiple path is a must-have thing for routers.
It may be used by the servers to balance outgoing traffic over multiple default gateways.
The previous implementation, RADIX_MPATH stayed in the shadow for too long.
It was not well maintained, which lead us to a vicious circle - people were using
non-contiguous mask or firewalls to achieve similar goals. As a result, some routing
daemons implementation still don't have multipath support enabled for FreeBSD.
Turning on ROUTE_MPATH by default would fix it. It will allow to reduce networking
feature gap to other operating systems. Linux and OpenBSD enabled similar support
at least 5 years ago.
ROUTE_MPATH does not consume memory unless actually used. It enables around ~1k LOC.
It does not bring any behaviour changes for userland.
Additionally, feature is (temporarily) turned off by the net.route.multipath sysctl
defaulting to 0.
Differential Revision: https://reviews.freebsd.org/D27428
Prefer atomics to critical section. This reduces the cost of the
increment operation and removes the possibility of it being interrupted
by counter_u64_zero().
Use CPU_FOREACH() macro to skip absent CPUs.
Replace hand-rolled address calculation with zpcpu_get().
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D27536
Allows recovery or diagnosis of a fatal page fault before panicking the
system.
Reviewed by: jhb, kp
Differential Revision: https://reviews.freebsd.org/D27534
- Push the kstack_contains check down into unwind_frame() so that it
is honored by DDB and DTrace.
- Check that the trapframe for an exception frame is contained in the
traced thread's kernel stack for DDB traces.
Reviewed by: markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27357
This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.
Reviewed by: kib, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27356
This allows GDB to print more useful backtraces when setting a breakpoint
on an assembly function.
Reviewed By: jhb
Differential Revision: https://reviews.freebsd.org/D27177
Ensure we initialize the static environment when not booting via
loader(8), and provide a static buffer if this is the case. This fixes
two issues.
First, performing the initialization ensures that kenv variables set in
the kernel's config file are honored. Previously, any new or overridden
values were ignored.
Second, providing the static buffer allows variables to be set in the
device tree's bootargs property of the chosen node. This can be set by
u-boot or by QEMU's '-append' flag. Attempting to this prior to this
change resulted in an early panic, since the static environment had no
buffer backing it.
Submitted by: syrinx (earlier version)
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D25034
In pmap_bootstrap(), we fill kernel_pmap->pm_active since it is
invariably active on all harts. However, this marks it as active even
for harts that don't exist in the system, which can cause issue when the
mask is passed to the SBI firmware via sbi_remote_sfence_vma().
Specifically, the SBI spec allows SBI_ERR_INVALID_PARAM to be returned
when an invalid hart is set in the mask.
The latest version of OpenSBI does not have this issue, but v0.6 does,
and this is triggering a recently added KASSERT in CI. Switch to only
setting bits in pm_active for harts that enter the system.
Reported by: Jenkins
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D27080
VM_ALLOC_WAITOK and vm_page_unwire_noq(), have eliminated the need for
many of the #includes.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D27052
- remove setting of register value which is not used until the next value is
set
- Use the L2_SHIFT constant when setting up L2 superpages
Submitted by: Antonin Houska <ah AT melesmeles DOT cz>
Version 0.2 of the SBI specification [1] marked the existing SBI
functions as "legacy" in order to move to a newer calling convention. It
also introduced a set of replacement extensions for some of the legacy
functionality. In particular, the TIME, IPI, and RFENCE extensions
implement and extend the semantics of their legacy counterparts, while
conforming to the newer version of the spec.
Update our SBI code to use the new replacement extensions when
available, and fall back to the legacy ones. These will eventually be
dropped, when support for version 0.2 is ubiquitous.
[1] https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
Submitted by: Danjel Q. <danq1222@gmail.com>
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26953
S-mode software has write access to the SIP.SSIP bit, so instead of
making a second round-trip through the SBI we can clear it ourselves.
The SBI spec has deprecated this function for this exactly this reason.
Submitted by: Danjel Q. <danq1222@gmail.com
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26952
The existing names were inherited from arm64, but we should prefer
RISC-V terminology. Change the prefix to SCAUSE, and further change the
names to better match the RISC-V spec and be more consistent with one
another. Also, remove two codes that are not defined for S-mode (machine
and hypervisor ecall).
While here, apply style(9) to some condition checks.
Reviewed by: kp
Discussed with: jrtc27
Differential Revision: https://reviews.freebsd.org/D26918
As was done for L3 PTEs in r362853, mask out the reserved bits when
extracting the physical address from an L2 PTE. Future versions of the
spec or custom implementations may make use of these reserved bits, in
which case the resulting physical address could be incorrect.
Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: kp, mhorne
Differential Revision: https://reviews.freebsd.org/D26607
Hiding this feature behind RB_VERBOSE is gratuitous. The tunable is enough
to limit its use to only those who explicitly request it.
Suggested by: kevans
Move dump_avail[] extern declaration and inlines into a new header
vm/vm_dumpset.h. This fixes default gcc build for mips.
Reviewed by: alc, scottph
Tested by: kevans (previous version)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D26741
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled. Otherwise, there is no
functional change. The mechanism can be disabled with
debug.fxrng_vdso_enable=0.
arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time. Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed. On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.
This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator. That change is
left for future discussion/work.
Reviewed by: kib (previous version)
Approved by: csprng (me -- only touching FXRNG here)
Differential Revision: https://reviews.freebsd.org/D22839
Create the RISC-V NOTES and LINT files. As of r366559, LINT configs are
no longer generated but checked in to the tree.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D26502
The boot metadata (also referred to as modinfo, or preload metadata)
provides information about the size and location of the kernel,
pre-loaded modules, and other metadata (e.g. the EFI framebuffer) to be
consumed during by the kernel during early boot. It is encoded as a
series of type-length-value entries and is usually constructed by
loader(8) and passed to the kernel. It is also faked on some
architectures when booted by other means.
Although much of the module information is available via kldstat(8),
there is no easy way to debug the metadata in its entirety. Add some
routines to parse this data and allow it to be printed to the console
during early boot or output via a sysctl.
Since the output can be lengthly, printing to the console is gated
behind the debug.dump_modinfo_at_boot kenv variable as well as the
BOOTVERBOSE flag. The sysctl to print the metadata is named
debug.dump_modinfo.
Reviewed by: tsoome
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26687
It is unlikely, but possible, that an unrecognized or unsupported
relocation type is encountered while trying to load a kernel module. If
this occurs we should offer the symbol index as a hint to the user.
While here, fix some small style issues.
Reviewed by: markj, kib (amd64 part, in D26701)
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Since r366355 and r366284 we panic on access faults rather than treating
them like page faults so this condition is never true.
Reviewed by: jhb (mentor), markj, mhorne
Approved by: jhb (mentor), markj, mhorne
Differential Revision: https://reviews.freebsd.org/D26686
We should never take instruction page faults when in the kernel, but by
using the standard page fault code we should get a more-informative
message about faulting on a NOFAULT page rather than branching to the
default case here and printing an "Unknown kernel exception ..."
message.
Reviewed by: jhb (mentor), markj
Approved by: jhb (mentor), markj
Differential Revision: https://reviews.freebsd.org/D26685
These names were inherited from the arm64 port and should be changed to
the RISC-V terminology.
Reviewed by: jhb (mentor), kp, markj
Approved by: jhb (mentor), kp, markj
Differential Revision: https://reviews.freebsd.org/D26671
Access faults in user mode are treated like TLB misses, which leads to an
endless loop of faults. It's less serious than the same fault in kernel mode,
because we can just terminate the process, but that's not ideal.
Treat user mode access faults as a bus error.
Suggested by: jrtc27
Reviewed by: br, jhb
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26621
Load/store/fetch access exceptions always indicate a violation of a PMP
rule. We can't treat those as page faults, because updating the page
table and trying again will only result in exactly the same access
exception recurring. This leaves us in an endless exception loop.
We cannot recover from these exceptions, so panic instead.
Reviewed by: jhb
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26544
Every other architecture defines this and this is required for
interrupts to work when using QEMU's PCI VirtIO devices (which all
report an interrupt line of 0) for two reasons.
Firstly, interrupt line 0 is wrong; they use one of 0x20-0x23 with the
lines being cycled across devices like normal. Moreover, RISC-V uses
INTRNG, whose IRQs are virtual as indices into its irq_map, so even if
we have the right interrupt line we still need to try and route the
interrupt in order to ultimately call into intr_map_irq and get back a
unique index into the map for the given line, otherwise we will use
whatever happens to be in irq_map[line] (which for QEMU where the line
is initialised to 0 results in using the first allocated interrupt,
namely the RTC on IRQ 11 at time of commit).
Note that pci_assign_interrupt will still do the wrong thing for INTRNG
when using a tunable, as it will bypass INTRNG entirely and use the
tunable's value as the index into irq_map, when it should instead
(indirectly) call intr_map_irq to allocate a new entry for the given
IRQ and treat the tunable as stating the physical line in use, which is
what one would expect. This, however, is a problem shared by all INTRNG
architectures, and not exclusive to RISC-V.
Reviewed by: kib
Approved by: kib
Differential Revision: https://reviews.freebsd.org/D26564
In the spirit of the GENERIC config, we should include the drivers required to
run on most supported platforms.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26501
On Ampere Altra systems, the sparse population of RAM within the
physical address space causes the vm_page_dump bitmap to be much
larger than necessary, increasing the size from ~8 Mib to > 2 Gib
(and overflowing `int` for the size).
Changing the page dump bitmap also changes the minidump file
format, so changes are also necessary in libkvm.
Reviewed by: jhb
Approved by: scottl (implicit)
MFC after: 1 week
Sponsored by: Ampere Computing, Inc.
Differential Revision: https://reviews.freebsd.org/D26131
These definitions were repeated by all architectures, with small
variations. Consolidate the common definitons in machine
independent code and use bitset(9) macros for manipulation. Many
opportunities for deduplication remain in the machine dependent
minidump logic. The only intended functional change is increasing
the bit index type to vm_pindex_t, allowing the indexing of pages
with address of 8 TiB and greater.
Reviewed by: kib, markj
Approved by: scottl (implicit)
MFC after: 1 week
Sponsored by: Ampere Computing, Inc.
Differential Revision: https://reviews.freebsd.org/D26129
One problem with the bus_space_read_N() and bus_space_write_N() family of
functions is that they provide no protection against exceptions which can
occur when no physical hardware or device responds to the read or write
cycles. In such a situation, the system typically would panic due to a
kernel-mode bus error. The bus_space_peek_N() and bus_space_poke_N() family
of functions provide a mechanism to handle these exceptions gracefully
without the risk of crashing the system.
Typical example is access to PCI(e) configuration space in bus enumeration
function on badly implemented PCI(e) root complexes (RK3399 or Neoverse
N1 N1SDP and/or access to PCI(e) register when device is in deep sleep state.
This commit adds a real implementation for arm64 only. The remaining
architectures have bus_space_peek()/bus_space_poke() emulated by using
bus_space_read()/bus_space_write() (without exception handling).
MFC after: 1 month
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D25371
that can be extended, but also ensure compile-time type checking. Refactor
common code out of arch-specific implementations. Move the mpr and mps
drivers to this new API. The template type remains visible to the consumer
so that it can be allocated on the stack, but should be considered opaque.
RISC-V is currently built with -Wno-format, which is how these went
undetected. Address them now before re-enabling those warnings.
Differential Revision: https://reviews.freebsd.org/D26319
The kernel adjusts the stack by TF_SIZE and the RISC-V ABI requires
that it remain 16-byte aligned.
Reported by: CHERI, jrtc27
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26328
Currently we use a single bit to indicate whether the virtual page is
part of a superpage. To support a forthcoming implementation of
non-transparent 1GB superpages, it is useful to provide more detailed
information about large page sizes.
The change converts MINCORE_SUPER into a mask for MINCORE_PSIND(psind)
values, indicating a mapping of size psind, where psind is an index into
the pagesizes array returned by getpagesizes(3), which in turn comes
from the hw.pagesizes sysctl. MINCORE_PSIND(1) is equal to the old
value of MINCORE_SUPER.
For now, two bits are used to record the page size, permitting values
of MAXPAGESIZES up to 4.
Reviewed by: alc, kib
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26238
This allows privileged userspace processes to find information about the
physical page backing a given mapping. It is useful in applications
such as DPDK which perform some of their own memory management.
Reviewed by: kib, jhb (previous version)
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D26237
sbi_init() sets mimpid, we can use that value.
Reviewed by: philip (mentor), kp (mentor)
Approved by: philip (mentor), kp (mentor)
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26092
I observed hangs post-r362977 in QEMU with -smp 2, in which one thread
would acquire write access to an rm_lock (sysctllock) and get stuck
waiting in smp_rendezvous_cpus while the other CPU was servicing a trap.
The other thread was waiting for read access to the same lock, thus
causing deadlock.
It's clear that this is just one symptom of a larger problem. The
general expectation of MI kernel code is that interrupts are enabled.
Violating this assumption will at best create some additional latency,
but otherwise might cause locking or other unforeseen issues. All other
architectures do so for some subset of trap values, but this somehow got
missed in the RISC-V port. Enable interrupts now during kernel page
faults and for all user trap types.
The code in exception.S already knows to disable interrupts while
handling the return from exception, so there are no changes required
there.
Reviewed by: jhb, markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26017
- Properly set up the frame pointer
- Hang if we return from mi_startup
- Whitespace
Clearing the frame pointer marks the end of the backtrace. This fixes
"bt 0" in ddb, which previously would unwind one frame too far.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D26016
This same check is used on other architectures. Previously this would
permit a stack frame to unwind into any arbitrary kernel address
(including unmapped addresses).
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D25996
There was an additional 7 bytes of compiler-inserted padding at the
end of the structure visible via 'ptype /o' in gdb.
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D25867
RISC-V doesn't support floating-point exceptions.
RISC-V Instruction Set Manual: Volume I: User-Level ISA, 11.2 Floating-Point
Control and Status Register: "As allowed by the standard, we do not support
traps on floating-point exceptions in the base ISA, but instead require
explicit checks of the flags in software. We considered adding branches
controlled directly by the contents of the floating-point accrued exception
flags, but ultimately chose to omit these instructions to keep the ISA simple."
We still need these functions, because some applications (notably Perl) call
them, but we cannot provide a meaningful implementation.
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D25740
QEMU's RISC-V virt machine provides syscon-power and syscon-reset
devices as the means by which to shutdown and reboot. We also need to
ensure that we have attached the syscon_generic device before attaching
any syscon_power devices, and so we introduce a new riscv_syscon device
akin to aw_syscon added in r327936. Currently the SiFive test finisher
is used as the specific implementation of such a syscon device.
Reviewed by: br, brooks (mentor), jhb (mentor)
Approved by: br, brooks (mentor), jhb (mentor)
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D25725
This device was originally used as part of the goldfish virtual hardware
platform used for emulating Android on QEMU, but is now also used as the
RTC for the RISC-V virt machine in QEMU. It provides a simple 64-bit
nanosecond timer exposed via a pair of memory-mapped 32-bit registers,
although only with 1s granularity.
Reviewed by: brooks (mentor), jhb (mentor), kp
Approved by: brooks (mentor), jhb (mentor), kp
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D25717
Being able to use tmpfs without kernel modules is very useful when building
small MFS_ROOT kernels without a real file system.
Including TMPFS also matches arm/GENERIC and the MIPS std.MALTA configs.
Compiling TMPFS only adds 4 .c files so this should not make much of a
difference to NO_MODULES build times (as we do for our minimal RISC-V
images).
Reviewed By: br (earlier version for riscv), brooks, emaste
Differential Revision: https://reviews.freebsd.org/D25317
The size of the containing structure was passed instead of the size of
the array. This happened to be harmless as the extra word copied is
one we copy in the next line anyway.
Reported by: CHERI (bounds check violation)
Reviewed by: brooks, imp
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D25791
During device attachment, all interrupt sources will bind to the BSP,
as it is the only processor online. This means interrupts must be
redistributed ("shuffled") later, during SI_SUB_SMP.
For the EARLY_AP_STARTUP case, this is no longer true. SI_SUB_SMP will
execute much earlier, meaning APs will be online and available before
devices begin attachment, and there will therefore be nothing to
shuffle.
All PIC-conforming interrupt controllers will handle this early
distribution properly, except for RISC-V's PLIC. Make the necessary
tweak to the PLIC driver.
While here, convert irq_assign_cpu from a boolean_t to a bool.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D25693
The FDT may contain a short /chosen/bootargs string which we should pass
to boot_parse_cmdline. Notably, this allows the use of qemu's -append
option to pass things like -s to boot to single user mode.
Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: mhorne
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25544
This removes SCTP from in-tree kernel configuration files. Now, SCTP
can be enabled by simply loading the module, as discussed on
freebsd-net@.
Reviewed by: tuexen
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D25611
We cannot complete the interrupt (i.e. write to the claims/complete register
until the interrupt handler has actually run. We don't run the interrupt
handler immediately from intr_isrc_dispatch(), we only schedule it for later
execution.
If we immediately complete it (i.e. before the interrupt handler proper has
run) the interrupt may be triggered again if the interrupt source remains set.
From RISC-V Instruction Set Manual: Volume II: Priviliged Architecture, 7.4
Interrupt Gateways:
"If a level-sensitive interrupt source deasserts the interrupt after the PLIC
core accepts the request and before the interrupt is serviced, the interrupt
request remains present in the IP bit of the PLIC core and will be serviced by
a handler, which will then have to determine that the interrupt device no
longer requires service."
In other words, we may receive interrupts twice.
Avoid that by postponing the completion until after the interrupt handler has
run.
If the interrupt is handled by a filter rather than by scheduling an interrupt
thread we must also complete the interrupt, so set up a post_filter handler
(which is the same as the post_ithread handler).
Reviewed by: mhorne
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D25531
This implementation doesn't have any major deviations from the other EFI
ports. I've copied the boilerplate from arm and arm64.
I've tested this with the following boot flows:
OpenSBI (M-mode) -> u-boot (S-mode) -> loader.efi -> FreeBSD
OpenSBI (M-mode) -> u-boot (S-mode) -> boot1.efi -> loader.efi -> FreeBSD
Due to the way that u-boot handles secondary CPUs, OpenSBI >= v0.7 is required,
as the HSM extension is needed to bring them up explicitly. Because of this,
using BBL as the SBI implementation will not be possible. Additionally, there
are a few recent u-boot changes that are required as well, all of which will be
present in the upcoming v2020.07 release.
Looks good: emaste
Differential Revision: https://reviews.freebsd.org/D25135
The top 10 bits of a pte are reserved by specification[1] and are not part of
the PPN.
[1] 'Volume II: RISC-V Privileged Architectures V20190608-Priv-MSU-Ratified',
'4.4.1 Addressing and Memory Protection', page 72: "The PTE format for Sv39 is
shown in Figure 4.18. ... Bits 63–54 are reserved for future use and must be
zeroed by software for forward compatibility."
Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: kp, mhorne
Differential Revision: https://reviews.freebsd.org/D25523
A very minor micro-optimization; t0 is not clobbered between the loop top and
bottom and there appear to be no other branches to this label.
Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: mhorne
Differential Revision: https://reviews.freebsd.org/D25524
If we panic we dump the registers for debugging. This is very useful, but it
missed several registers (ra, sp, gp and tp).
Log these as well. Especially the return address value is extremely useful.
Sponsored by: Axiado
This temporary mapping will become optional. Booting via loader(8)
means that the DTB will have already been copied into the kernel's
staging area, and is therefore covered by the early KVA mappings.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D24911
In locore, we must detect and handle different arguments passed by
loader(8) compared to what we recieve when booting directly via SBI
firmware. Currently we receive the hart ID in a0 and a pointer to the
device tree blob in a1. loader(8) provides only a pointer to its
metadata in a0.
The solution to this is to add an additional entry point, _alt_start.
This will be placed first in the .text section, so SBI firmware will
enter here, and jump to the common pagetable setup shortly after. Since
loader(8) understands our ELF kernel, it will enter at the ELF's entry
address, which points to _start. This approach leads to very little
guesswork as to which way we booted.
Fix-up initriscv() to parse the loader's metadata, continuing to use
fake_preload_metadata() in the SBI direct boot case.
Reviewed by: markj, jrtc27 (asm portion)
Differential Revision: https://reviews.freebsd.org/D24912
Currently we only call sbi_shutdown in cpu_reset, which means we reach
"Please press any key to reboot." even when RB_POWEROFF is set, and only
once the user presses a key do we then shutdown. Instead, register a
shutdown_final event handler and make an SBI shutdown call if
RB_POWEROFF is set.
Reviewed by: br, jhb (mentor), kp
Approved by: br, jhb (mentor), kp
Differential Revision: https://reviews.freebsd.org/D25183
This can happen with very large kernels (e.g. ones embedding a root
filesystem). The DTB written by OpenSBI/BBL is quite small so this is
unlikely to hit important data, but if it does this can result in very
confusing and hard-to-debug crashes. Add a KASSERT() and a verbose print
to catch this problem with debug kernels.
While this will not print any output by default if it fails (that would
depend on EARLY_PRINTF), at least the kernel now halts reliably instead
of randomly crashing.
Reviewed By: mhorne
Differential Revision: https://reviews.freebsd.org/D25153
By default OpenSBI and BBL will pass the DTB at a 2MB-aligned address.
However, by default there are no 2MB aligned regions between the SBI and
the kernel, so we have to choose a 2MB aligned region after the kernel.
OpenSBI defaults to placing the DTB 32MB after the start of the kernel but
this is not sufficient for a kernel with a large MFS embedded.
We could increase this offset to a larger number (e.g. 64/128/256) but that
imposes restrictions on the minimum RAM size.
Another solution would be to place the DTB between OpenSBI and the kernel
at 1MB alignment, but current locore.S code assumes 2MB alignment.
With this change I can now boot on QEMU with an OpenSBI configured to
store the DTB at an offset of 1MB.
See also https://github.com/riscv/opensbi/issues/169
Reviewed By: mhorne
Differential Revision: https://reviews.freebsd.org/D25151
The trampoline code used for loading gzipped a.out kernels on arm was
removed in r350436. A portion of this code allowed for DDB to find the
symbol tables when booting without loader(8), and some of this was
untouched in the removal. Remove it now.
Differential Revision: https://reviews.freebsd.org/D24950
This is in preparation for booting via loader(8). Lift these macros from arm64
so we don't need to worry about the size when inserting new elements. This
could have been done in r359673, but I didn't think I would be returning to
this function so soon.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D24910
This reapplies logical r360944 and r360946 (reverting r360955), with fixed
copystr() stand-in replacement macro. Eventually the goal is to convert
consumers and kill the macro, but for a first step it helps if the macro is
correct.
Prior commit message:
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults. It's just
an older incarnation of the now-more-common strlcpy().
Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.
Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy (with correction from brooks@ -- thanks).
Remove N redundant MI implementations of copystr. For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.
Reviewed by: jhb (earlier version)
Discussed with: brooks (thanks!)
Differential Revision: https://reviews.freebsd.org/D24672
When protecting a superpage, we would previously fall through to the
non-superpage case and read the contents of the superpage as PTEs,
potentially modifying them and trying to look up underlying VM pages that
don't exist if they happen to look like PTEs we would care about. This led
to nginx causing an unexpected page fault in pmap_protect that panic'ed the
kernel. Instead, if we see a superpage, we are done for this range and
should continue to the next.
Reviewed by: markj, jhb (mentor)
Approved by: markj, jhb (mentor)
Differential Revision: https://reviews.freebsd.org/D24827
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults. It's just
an older incarnation of the now-more-common strlcpy().
Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.
Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy.
Remove N redundant MI implementations of copystr. For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D24672
The addition of the HSM SBI extension to OpenSBI introduces a new
breaking change: secondary harts will remain parked in the firmware,
until they are brought up explicitly via sbi_hsm_hart_start(). Add
the call to do this, sending the secondary harts to mpentry.
If the HSM extension is not present, secondary harts are assumed to be
released by the firmware, as is the case for OpenSBI =< v0.6 and BBL.
In the case that the HSM call fails we exclude the CPU, notify the
user, and allow the system to proceed with booting.
Reviewed by: markj (older version)
Differential Revision: https://reviews.freebsd.org/D24497
APs enter the kernel at the same point as the BSP, the _start routine.
They then jump to mpentry, but not before storing the kernel's physical
load address in the s9 register. Extract this calculation into its own
routine, so that APs can be instructed to enter directly from mpentry.
Differential Revision: https://reviews.freebsd.org/D24495
Now that hw.machine_arch handles soft-float vs hard-float there is no
longer a reason for this config.
Submitted by: mhorne (kern.mk hunk)
Reviewed by: imp (earlier version), kp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24544
For userland, MACHINE_ARCH reflects the current ABI via preprocessor
directives. For the kernel, the hw.machine_arch sysctl uses the ELF
header flags of the current process to select the correct MACHINE_ARCH
value.
Reviewed by: imp, kp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24543
pmap_bootstrap() expects the kernel's physical load address, but we have
been providing the start of physical memory. This had the nice effect of
protecting the memory used by the SBI runtime firmware, but now that we
have alternate means of achieving that, we should provide the correct
value. This will free up any memory between the SBI firmware and the
kernel for allocation.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D24156
The device tree may contain a "reserved-memory" node, whose purpose is
to communicate sections of physical memory that should not be used for
general allocations. Add the logic to parse and exclude these regions.
The particular motivation for this is protection of the SBI runtime
firmware. Currently, there is no mechanism through which the SBI
can communicate the details of its reserved memory region(s) to
a supervisor payload. There has been some discussion recently on how
this can be achieved [1], and it seems that the path going forward
will be to add an entry to the reserved-memory node.
This hasn't caused any issues for us yet, since we exclude all physical
memory below the kernel's load address from being allocated, and on all
currently supported platforms this covers the SBI firmware region. This
will change in another commit, so as a safety measure, ensure that the
lowest 2MB of memory is excluded if this region has not been reported.
[1] https://github.com/riscv/riscv-sbi-doc/pull/37
Reviewed by: markj, nick (older version)
Differential Revision: https://reviews.freebsd.org/D24155
Replace our hand-rolled functions with the generic ones provided by
kern/subr_physmem.c. This greatly simplifies the initialization of
physical memory regions and kernel globals.
Tested by: nick
Differential Revision: https://reviews.freebsd.org/D24154
The location of the device-tree blob is passed to the kernel by the
previous booting stage (i.e. BBL or OpenSBI). Currently, we leave it
untouched and mark the 1MB of memory holding it as unavailable.
Instead, do what is done by other fake_preload_metadata() routines and
copy to the DTB to KVA space. This is more in line with what loader(8)
will provide us in the future, and it allows us to reclaim the hole in
physical memory.
Reviewed by: markj, kp (earlier version)
Differential Revision: https://reviews.freebsd.org/D24152
The only way to flush the local hart's icache is with a FENCE.I (or an
equivalent SBI call); a normal FENCE is insufficient and, for the
single-hart case, unnecessary.
Reviewed by: jhb (mentor), markj
Approved by: jhb (mentor), markj
Differential Revision: https://reviews.freebsd.org/D24317
Summary:
The parentheses being in the wrong place means that, for L3 pages,
oldpte has all bits except PTE_V cleared, and so all the subsequent
checks against oldpte will fail, causing us to bail out and not retry
the faulting instruction after an SFENCE.VMA. This causes a WITNESS +
INVARIANTS kernel to fault on the "Chisel P3" (BOOM-based) DARPA SSITH
GFE SoC in pmap_init when writing to pv_table and, being a nofault
entry, subsequently panic with:
panic: vm_fault_lookup: fault on nofault entry, addr: 0xffffffc004e00000
Reviewed by: markj
Approved by: markj
Differential Revision: https://reviews.freebsd.org/D24315
This driver supports SiFive's FE310 Always-on (AON) peripheral's
Real-time clock (RTC) and Watchdog timer (WDT). AON has other
functionality that this driver could support such as the power
management unit (PMU) but that functionality hasn't been implemented.
Reviewed by: philip (mentor), kp (mentor)
Approved by: philip (mentor)
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D24170
Modern debuggers and process tracers use ptrace() rather than procfs
for debugging. ptrace() has a supserset of functionality available
via procfs and new debugging features are only added to ptrace().
While the two debugging services share some fields in struct proc,
they each use dedicated fields and separate code. This results in
extra complexity to support a feature that hasn't been enabled in the
default install for several years.
PR: 244939 (exp-run)
Reviewed by: kib, mjg (earlier version)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D23837
Instead, dynamically allocate a page for the boot stack of each AP when
starting them up, like we do on x86. This shrinks the bss by
MAXCPU*KSTACK_PAGES pages, which corresponds to 4MB on arm64 and 256KB
on riscv.
Duplicate the logic used on x86 to free the bootstacks, by using a
sysinit to wait for each AP to switch to a thread before freeing its
stack.
While here, mark some static MD variables as such.
Reviewed by: kib
MFC after: 1 month
Sponsored by: Juniper Networks, Klara Inc.
Differential Revision: https://reviews.freebsd.org/D24158
When I implemented MD DYNAMIC parsing, I was originally passing a
linker_file_t so that the MD code could relocate pointers.
However, it turns out this isn't even filled in until later, so it was
always 0.
Just pass the load base (ef->address) directly, as that's really the only
thing we were interested in in the first place.
This fixes a crash on RB800 where it was trying to write to an unmapped
address when updating the GOT.
Reviewed by: jhibbits
Sponsored by: Tag1 Consulting, Inc.
Differential Revision: https://reviews.freebsd.org/D24105
This silences an "unused label" warning as well as fixes the attach fail
path that wasn't releasing resources.
Submitted by: Nicholas O'Brien <nickisobrien_gmail.com>
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D24004
Use __riscv_flen instead of __riscv_float_abi_soft. While the latter works for
userland (and one could argue it's more correct), it fails for the kernel. We
compile the kernel with -mabi=lp64 (eg soft float abi) to avoid floating point
instructions in the kernel. We also compile the kernel -march=rv64imafdc for
hard float kernels (eg those with options FPE), but with -march=rv64imac for
softfloat kernels (eg those with FPE). Since we do this, in the kernel (as in
userland) __riscv_flen will be defined for 'riscv64' and not for 'riscv64sf'.
This also removes the -DMACHINE_ARCH hack now that it's no longer needed.
Longer term, we should return the ABI from the sysctl hw.machine_arch like on
amd64 for i386 binaries.
Suggested by: mhorne@
Differential Revision: https://reviews.freebsd.org/D23813
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
GENERICSF is just like GENERIC, only creates a soft-float kernel. Omit it from the
universe build for now.
Reviewed by: philip
Differential Revision: https://reviews.freebsd.org/D23812
MACHINE_ARCH sets the hw.machine_arch sysctl in the kernel. In userspace
it sets MACHINE_ARCH in bmake, which bsd.cpu.mk uses to configure the
target ABI for ports.
For riscv64sf builds (i.e. soft-float) that needs to be riscv64sf, but
the sysctl didn't reflect that. It is static.
Set the define from the riscv makefile so that we correctly reflect our
actual build (i.e. riscv64 or riscv64sf), depending on what TARGET_ARCH
we were built with.
That still doesn't satisfy userspace builds (e.g. bmake), so check if
we're building with a software-floating point toolchain there. That
check doesn't work in the kernel, because it never uses floating point.
Reviewed by: philip (previous version), mhorne
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D23741
This is taken from the arm64 version, with the following simplifications:
- Our current pmap implementation uses a 3-level paging scheme
- The "mode" field has been omitted since RISC-V PTEs don't encode
typical mode attributes
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D23594
Always use the kdb_thr_ctx() for db_trace_thread() as on other
architectures. Initialize pcb_ra to be the sepc from the saved
trapframe rather than the saved ra to avoid skipping a frame.
Reviewed by: mhorne, br
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23513
While here, add an extra line of information for exceptions and
interrupts and compress the per-frame line down to one line to match
other architectures.
Reviewed by: mhorne, br
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23508
While cause codes higher than 16 are reserved, the exception code
field of the register is defined to be all bits but the upper-most
bit.
Reviewed by: mhorne
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23510
While here, remove a local variable to avoid the CSR read in non-debug
kernels.
Reviewed by: mhorne
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23511
In practice this discarded all characters entered at the DDB prompt.
Reviewed by: br
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23509
This fixes continuing from debug.kdb.enter=1 after enabling the use of
compressed instructions since the compiler can emit the two byte
c.ebreak instead of the 4 byte ebreak.
Reviewed by: br
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23507
This reverts r177661. The change is no longer very useful since
out-of-tree KLDs will be built to target SMP kernels anyway. Moveover
it breaks the KBI in !SMP builds since cpuset_t's layout depends on the
value of MAXCPU, and several kernel interfaces, notably
smp_rendezvous_cpus(), take a cpuset_t as a parameter.
PR: 243711
Reviewed by: jhb, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23512
The PRCI exports tlclk as a constant fixed divisor clock, defined as 1/2
of the coreclk frequency. In older FU540 device trees (such as the one
provided by SiFive), tlclk is represented as its own entity, and is
automatically registered as a fixed-divisor-clock. Unfortunately the
upstream FU540 device tree (that we have in our tree) represents tlclk
as an output of the PRCI block, and we must register it manually. At
worst, users of the old device tree will end up with an unreferenced
duplicate of tlclk.
This fixes device attachment for the SiFive UART on newer device trees,
since it references tlclk via the PRCI.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D23406
Add two additional compat strings that can be used to identify the PRCI.
With newer device trees the PRCI has two parents, hfclk and rtcclk, so
allow the driver to attach when more than one parent is found.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D23405
The PRCI module exports three PLLs. Currently only the coreclk/corepll
is registered, so add the logic to register the DDR (memory) and GEMGX
(ethernet) clocks as well. These clocks are unused at the moment.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D23404
Rather than trying to blacklist which bits userland can't write to via
sigreturn() or setcontext(), only permit changes to whitelisted bits.
- Permit arbitrary writes to bits in the user-writable USTATUS
register that shadows SSTATUS.
- Ignore changes in write-only bits maintained by the CPU.
- Ignore the user-supplied value of the FS field used to track
floating point state and instead set it to a value matching the
actions taken by set_fpcontext().
Discussed with: mhorne
MFC after: 2 weeks
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23338
After r355784 the td_oncpu field is no longer synchronized by the thread
lock, so the stack capture interrupt cannot be delievered precisely.
Fix this using a loop which drops the thread lock and restarts if the
wrong thread was sampled from the stack capture interrupt handler.
Change the implementation to use a regular interrupt instead of an NMI.
Now that we drop the thread lock, there is no advantage to the latter.
Simplify the KPIs. Remove stack_save_td_running() and add a return
value to stack_save_td(). On platforms that do not support stack
capture of running threads, stack_save_td() returns EOPNOTSUPP. If the
target thread is running in user mode, stack_save_td() returns EBUSY.
Reviewed by: kib
Reported by: mjg, pho
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23355
The stack pointer is swapped with the sscratch CSR just before the
jump to cpu_exception_handler_user where the first instruction swaps
it again. The two swaps together are a no-op, but the csr swap
instructions can be expensive (e.g. on Bluespec RISC-V cores csr swap
instructions force a full pipeline stall).
Reported by: jrtc27
Reviewed by: br
MFC after: 2 weeks
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23394
cpu_switch/throw() and savectx() do not save or restore any values in
these fields which mostly held non-callee-save registers.
makectx() copied these fields from kdb_frame, but they weren't used
except for PC_REGS using pcb_sepc. Change PC_REGS to use
kdb_frame->tf_sepc directly instead.
Reviewed by: br
MFC after: 2 weeks
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23395
The SD bit is defined as the MSB of the sstatus register, meaning its
position will vary depending on the CSR's length. Previously, there were
two (unused) defines for this, for the 32 and 64-bit cases, but their
definitions were swapped.
Consolidate these into one define: SSTATUS_SD, and make the definition
dependent on the value of __riscv_xlen.
Reviewed by: br
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D23402
