Use of compiler builtin ffs/ctz functions will result in optimized
instruction sequences when possible, and fall back to calling a function
provided by the compiler run-time library. We have slowly shifted our
platforms to take advantage of these builtins in 60645781d6 (arm64),
1c76d3a9fb (arm), 9e319462a0 (powerpc, partial).
Some platforms still rely on the libkern implementations of these
functions provided by libkern, namely riscv, powerpc (ffs*, flsll), and
i386 (ffsll and flsll). These routines are slow, as they perform a
linear search for the bit in question. Even on platforms lacking
dedicated bit-search instructions, such as riscv, the compiler library
will provide better-optimized routines, e.g. by using binary search.
Consolidate all definitions of these functions (whether currently using
builtins or not) to libkern.h. This should result in equivalent or
better performing routines in all cases.
One wart in all of this is the existing HAVE_INLINE_F*** macros, which
we use in a few places to conditionally avoid the slow libkern routines.
These aren't easily removed in one commit. For now, provide these
defines unconditionally, but marked for removal after subsequent
cleanup.
Removal of the now unused libkern routines will follow in the next
commit.
Reviewed by: dougm, imp (previous version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40698
This avoids bloating the kernel image when MAXCPU is large.
A follow-up patch for kgdb and other kernel debuggers is needed since
the stoppcbs symbol is now a pointer. Bump __FreeBSD_version so that
debuggers can use osreldate to figure out how to handle stoppcbs.
PR: 269572
MFC after: never
Reviewed by: mjg, emaste
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39806
The SPDX folks have obsoleted the BSD-2-Clause-NetBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
When vm_map_remove() is called from vm_swapout_map_deactivate_pages()
due to swapout, PKRU attributes for the removed range must be kept
intact. Provide a variant of pmap_remove(), pmap_map_delete(), to
allow pmap to distinguish between real removes of the UVA mappings
and any other internal removes, e.g. swapout.
For non-amd64, pmap_map_delete() is stubbed by define to pmap_remove().
Reported by: andrew
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39556
Very old versions of gcc defined _BIG_ENDIAN and _LITTLE_ENDIAN. So to
work around that, we undefined them here. However, that causes problems
for programs that do:
(and many other variations on that theme). Since this often is the
result of weirdly nested includes in the ports world that are hard to
unwind, drop this workaround to help more ports build out of the box.
If there's still an issue here (and my testing hasn't shown it), we'll
fix the issue in a brand-new way once I have a reproducer.
This fixes the mesa-devel build, and others
Sponsored by: Netflix
Tested by: pkubaj
MFC After: 3 days
Differential Revision: https://reviews.freebsd.org/D38564
Remove the platform-specific definitions of VM_BATCHQUEUE_SIZE
for amd64 and powerpc64, and instead treat all 64-bit platforms
identically. This has the effect of increasing the arm64
and riscv VM_BATCHQUEUE_SIZE to match that of other platforms.
Reviewed by: jhb, markj
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D37707
Rather than waiting until the batchqueue is full to acquire the lock &
process the queue, we now start trying to acquire the lock using trylocks
when the batchqueue is 1/2 full. This removes almost all contention on the
vm pagequeue mutex for for our busy sendfile() based web workload.
It also greadly reduces the amount of time a network driver ithread
remains blocked on a mutex, and eliminates some packet drops under
heavy load.
So that the system does not loose the benefit of processing large
batchqueues, I've doubled the size of the batchqueues. This way, when
there is no contention, we process the same batch size as before.
This has been run for several months on a busy Netflix server, as well
as on my personal desktop.
Reviewed by: markj
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D37305
This matches the return type of pmap_mapdev/bios.
Reviewed by: kib, markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36548
This applies one of the changes from
5567d6b441 to other architectures
besides arm64.
Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36263
These files no longer depend on the macros required when these checks
were added.
PR: 263102 (exp-run)
Reviewed by: brooks, imp, emaste
Differential Revision: https://reviews.freebsd.org/D34804
After b5d227b0 FreeBSD was panicking on boot with "Duplicate free" in
UMA. Analyzing the asm, the '1' mask was treated as an integer, rather
than a long, causing 'slw' (shift left word) to be used for the shifting
instruction, not 'sld' (shift left double). This means the upper bits
of the bitfield were not getting used, resulting in corruption of the
bitfield.
While fixing this, the 'and' check of the mask does not need to be
recorded, so don't record (drop the '.').
Add machine-optimized implementations for the following:
* atomic_testandset_int
* atomic_testandclear_int
* atomic_testandset_long
* atomic_testandclear_long
This fixes the build with ISA_206_ATOMICS enabled.
Add the associated atomic_testandset_32, atomic_testandclear_32, so
that ice(4) can potentially build.
When a DMA request using bounce pages completes, a swi is triggered to
schedule pending DMA requests using the just-freed bounce pages. For
a long time this bus_dma swi has been tied to a "virtual memory" swi
(swi_vm). However, all of the swi_vm implementations are the same and
consist of checking a flag (busdma_swi_pending) which is always true
and if set calling busdma_swi. I suspect this dates back to the
pre-SMPng days and that the intention was for swi_vm to serve as a
mux. However, in the current scheme there's no need for the mux.
Instead, remove swi_vm and vm_ih. Each bus_dma implementation that
uses bounce pages is responsible for creating its own swi (busdma_ih)
which it now schedules directly. This swi invokes busdma_swi directly
removing the need for busdma_swi_pending.
One consequence is that the swi now works on RISC-V which had previously
failed to invoke busdma_swi from swi_vm.
Reviewed by: imp, kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D33447
The header exports the following:
- Definition of struct tcb.
- Helpers to get/set the tcb for the current thread.
- TLS_TCB_SIZE (size of TCB)
- TLS_TCB_ALIGN (alignment of TCB)
- TLS_VARIANT_I or TLS_VARIANT_II
- TLS_DTV_OFFSET (bias of pointers in dtv[])
- TLS_TP_OFFSET (bias of "thread pointer" relative to TCB)
Note that TLS_TP_OFFSET does not account for if the unbiased thread
pointer points to the start of the TCB (arm and x86) or the end of the
TCB (MIPS, PowerPC, and RISC-V).
Note also that for amd64, the struct tcb does not include the unused
tcb_spare field included in the current structure in libthr. libthr
does not use this field, and the existing calls in libc and rtld that
allocate a TCB for amd64 assume it is the size of 3 Elf_Addr's (and
thus do not allocate room for tcb_spare).
A <sys/_tls_variant_i.h> header is used by architectures using
Variant I TLS which uses a common struct tcb.
Reviewed by: kib (older version of x86/tls.h), jrtc27
Sponsored by: The University of Cambridge, Google Inc.
Differential Revision: https://reviews.freebsd.org/D33351
After a round of cleanups in late 2020, all definitions are
functionally identical.
This removes a rotted __aligned(8) on arm. It was added in
b7112ead32 and was intended to align the
args member so that 64-bit types (off_t, etc) could be safely read on
armeb compiled with clang. With the removal of armev, this is no
longer needed (armv7 requires that 32-bit aligned reads of 64-bit
values be supported and we enable such support on armv6). As further
evidence this is unnecessary, cleanups to struct syscall_args have
resulted in args being 32-bit aligned on 32-bit systems. The sole
effect is to bloat the struct by 4 bytes.
Reviewed by: kib, jhb, imp
Differential Revision: https://reviews.freebsd.org/D33308
We do not consider the space reserved for the pcb to be part of the
total kstack size, so it should not be included in the calculation of
the used stack size.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
It was never implemented on powerpc or riscv and appears to have been
unused since it was added in 1998. No functional change intended.
Reviewed by: kp, glebius, cy
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33093
When constructing the set of dumpable pages, use the bitset provided by
the state argument, rather than assuming vm_page_dump invariably. For
normal kernel minidumps this will be a pointer to vm_page_dump, but when
dumping the live system it will not.
To do this, the functions in vm_dumpset.h are extended to accept the
desired bitset as an argument. Note that this provided bitset is assumed
to be derived from vm_page_dump, and therefore has the same size.
Reviewed by: kib, markj, jhb
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D31992
The minidump code is written assuming that certain global state will not
change, and rightly so, since it executes from a kernel debugger
context. In order to support taking minidumps of a live system, we
should allow copies of relevant global state that is likely to change to
be passed as parameters to the minidumpsys() function.
This patch does the work of parameterizing this function, by adding a
struct minidumpstate argument. For now, this struct allows for copies of
the kernel message buffer, and the bitset that tracks which pages should
be dumped (vm_page_dump). Follow-up changes will actually make use of
these arguments.
Notably, dump_avail[] does not need a snapshot, since it is not expected
to change after system initialization.
The existing minidumpsys() definitions are renamed, and a thin MI
wrapper is added to kern_dump.c, which handles the construction of
the state struct. Thus, calling minidumpsys() remains as simple as
before.
Reviewed by: kib, markj, jhb
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D31989
Current implementation of Radix MMU doesn't support mapping
arbitrary virtual addresses, such as the ones generated by
"direct mapping" I/O addresses. This caused the system to hang, when
early I/O addresses, such as those used by OpenFirmware Frame Buffer,
were remapped after the MMU was up.
To avoid having to modify mmu_radix_kenter_attr just to support this
use case, this change makes early I/O map use virtual addresses from
KVA area instead (similar to what mmu_radix_mapdev_attr does), as
these can be safely remapped later.
Reviewed by: alfredo (earlier version), jhibbits (in irc)
MFC after: 2 weeks
Sponsored by: Instituto de Pesquisas Eldorado (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D31232
The implementation of the progress bar is simple, but duplicated for
most minidump implementations. Extract the common bits to kern_dump.c.
Ensure that the bar is reset with each subsequent dump; this was only
done on some platforms previously.
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D31885
The function is identical in each minidump implementation, so move it to
vm_phys.c. The only slight exception is powerpc where the function was
public, for use in moea64_scan_pmap().
Reviewed by: kib, markj, imp (earlier version)
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D31884
Summary:
Failure to update the FP / vector state was causing daemon(3) to violate C ABI by failing to preserve nonvolatile registers.
This was causing a weird issue where moused was not working on PowerBook G4s when daemonizing, but was working fine when running it foreground.
Force saving off the same state that cpu_switch() does in cases where we are about to copy a thread.
MFC after: 1 week
Sponsored by: Tag1 Consulting, Inc.
Test Plan:
```
/*
* Test for ABI violation due to side effects of daemon(3).
*
* NOTE: Compile with -O2 to see the effect.
*/
/* Allow compiling for Linux too. */
static double test = 1234.56f;
/*
* This contrivance coerces clang to not bounce the double
* off of memory again in main.
*/
void __attribute__((noinline))
print_double(int j1, int j2, double d)
{
printf("%f\n", d);
}
int
main(int argc, char *argv[])
{
print_double(0, 0, test);
if (daemon(0, 1)) {
}
/* Compiler assumes nonvolatile regs are intact... */
print_double(0, 0, test);
return(0);
}
```
Working output:
```
1234.560059
1234.560059
```
Output in broken case:
```
1234.560059
0.0
```
Reviewers: #powerpc
Subscribers: jhibbits, luporl, alfredo
Tags: #powerpc
Differential Revision: https://reviews.freebsd.org/D29851
which is the place to put MD asserts about allocated pages.
On amd64, verify that allocated page does not belong to the kernel
(text, data) or early allocated pages.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31121
As the Processor Version Register (PVR) is a 32-bit PowerPC
register, change mfpvr() return type to match it and avoid
type casts on its callers.
Suggested by: jhibbits
Reviewed by: jhibbits, imp
Sponsored by: Instituto de Pesquisas Eldorado (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D31332
The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.
This reapplies 3a522ba1bc with a fix for
the static assertion failure on i386.
Approved by: markj (mentor)
Reviewed by: kib, bcr (manpages)
Differential Revision: https://reviews.freebsd.org/D29185
The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.
Approved by: markj (mentor)
Reviewed by: kib, bcr (manpages)
Differential Revision: https://reviews.freebsd.org/D29185
Many of these typedefs are the same across all architectures or can
be set based on an architecture-independent compiler-provided macro
(e.g. __SIZEOF_SIZE_T__). These macros have been available since GCC 4.6
and Clang sometime before 3.0 (godbolt.org does not have any older clang
versions installed).
I originally considered using the compiler-provided `__FOO_TYPE__` directly.
However, in order to do so we have to check that those match the previous
typedef exactly (not just that they have the same size) since any change
would be an ABI break. For example, changing `long` to `long long` results
in different C++ name mangling. Additionally, Clang and GCC disagree on
the underlying type for some of (u)int*_fast_t types, so this change
only moves the definitions that are identical across all architectures
and does not touch those types.
This de-deduplication will allow us to have a smaller diff downstream in
CheriBSD: we only have to only change the (u)intptr_t definition in
sys/_types.h in CheriBSD instead of having to change machine/_types.h for
all CHERI-enabled architectures (currently RISC-V, AArch64 and MIPS).
Reviewed By: imp, kib
Differential Revision: https://reviews.freebsd.org/D29895
types.h defines device_t as a typedef of struct device *. struct device
is defined in subr_bus.c and almost all of the kernel uses device_t.
The LinuxKPI also defines a struct device, so type confusion can occur.
This causes bugs and ambiguity for debugging tools. Rename the FreeBSD
struct device to struct _device.
Reviewed by: gbe (man pages)
Reviewed by: rpokala, imp, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29676
This is intended to be used with memory mapped IO, e.g. from
bus_space_map with no flags, or pmap_mapdev.
Use this new memory type in the map request configured by
resource_init_map_request, and in pciconf.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D29692
Rename cpu_sleep() to mpc745x_sleep() to denote what it's actually
intended for. This function is very G4-specific, and will not work on
any other CPU. This will afterward eliminate a
platform_smp_timebase_sync() call by directly updating the timebase
instead.
The POWER7 subword atomics were not using the correct instructions for
byte and halfword stores in the atomic_fcmpset code.
This only affects builds with custom CFLAGS that have explicitly enabled
ISA_206_ATOMICS.
The remote protocol allows for implementations to report more specific
reasons for the break in execution back to the client [1]. This is
entirely optional, so it is only implemented for amd64, arm64, and i386
at the moment.
[1] https://sourceware.org/gdb/current/onlinedocs/gdb/Stop-Reply-Packets.html
Reviewed by: jhb
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
NetApp PR: 51
Differential Revision: https://reviews.freebsd.org/D29174
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
