old or previous value instead of void. This is not as is documented
in atomic(9), but is API (and ABI) compatible and simply makes sense.
This feature will primarily be used for atomic PTE updates in PMAP/ng.
a stack trace from ddb, the output will pause with a '--More--' prompt
every 18 lines. If you hit Enter, it will print another line and prompt
again. If you hit space it will output another page and then prompt.
If you hit 'q' or 'x' it will abort the rest of the stack trace.
- Fix the sparc64 userland stack trace to honor the total count of lines
to print. This is useful if your trace happens to walk back onto
0xdeadc0de and gets stuck in an endless loop.
MFC after: 1 month
Tested on: i386, alpha, sparc64
Completely remove the remaining EFI includes and add our own (type)
definitions instead. While here, abstract more of the internals by
providing interface functions.
EFI headers and put them all in <machine/fpu.h>. The Intel EFI headers
conflict with the Intel ACPI headers (duplicate type definitions), so
are being phased out in the kernel.
and which takes a M_WAITOK/M_NOWAIT flag argument.
Add compatibility isa_dmainit() macro which whines loudly if
isa_dma_init() fails.
Problem uncovered by: tegge
and was propagated to nearly every platform. The boundary of the child needs
to consider the boundary of the parent and pick the minimum of the two, not
the maximum. However, if either is 0 then pick the appropriate one.
This bug was exposed by a recent change to ATA, which should now be fixed by
this change. The alignment and maxsegsz tag attributes likely also need
a similar review in the near future.
This is a MT5 candidate.
Reviewed by: marcel
Submitted by: sos (in part)
the alignment and boundary constraints are being respected, which
fixes the reported ATA problems with SiI chips.
I consider the busdma implementation worrisome nonetheless. Not
only is there too much MI code duplicated in MD files, there's a
lot of questionable code. I smell a wholesale, cross-platform
overhaul coming...
MT5 candidate.
but with slightly cleaned up interfaces.
The KSE structure has become the same as the "per thread scheduler
private data" structure. In order to not make the diffs too great
one is #defined as the other at this time.
The KSE (or td_sched) structure is now allocated per thread and has no
allocation code of its own.
Concurrency for a KSEGRP is now kept track of via a simple pair of counters
rather than using KSE structures as tokens.
Since the KSE structure is different in each scheduler, kern_switch.c
is now included at the end of each scheduler. Nothing outside the
scheduler knows the contents of the KSE (aka td_sched) structure.
The fields in the ksegrp structure that are to do with the scheduler's
queueing mechanisms are now moved to the kg_sched structure.
(per ksegrp scheduler private data structure). In other words how the
scheduler queues and keeps track of threads is no-one's business except
the scheduler's. This should allow people to write experimental
schedulers with completely different internal structuring.
A scheduler call sched_set_concurrency(kg, N) has been added that
notifies teh scheduler that no more than N threads from that ksegrp
should be allowed to be on concurrently scheduled. This is also
used to enforce 'fainess' at this time so that a ksegrp with
10000 threads can not swamp a the run queue and force out a process
with 1 thread, since the current code will not set the concurrency above
NCPU, and both schedulers will not allow more than that many
onto the system run queue at a time. Each scheduler should eventualy develop
their own methods to do this now that they are effectively separated.
Rejig libthr's kernel interface to follow the same code paths as
linkse for scope system threads. This has slightly hurt libthr's performance
but I will work to recover as much of it as I can.
Thread exit code has been cleaned up greatly.
exit and exec code now transitions a process back to
'standard non-threaded mode' before taking the next step.
Reviewed by: scottl, peter
MFC after: 1 week
The removed argument could trivially be derived from the remaining one.
That in turn should be the same as curthread, but it is possible that curthread could be expensive to derive on some syste,s so leave it as an argument.
Having both proc and thread as an argumen tjust gives an opportunity for
them to get out sync.
MFC after: 3 days
in diagnostics. It has outlived its usefulness and has started
causing panics for people who turn on DIAGNOSTIC, in what is otherwise
good code.
MFC after: 2 days
these two reasons:
1. On ia64 a function pointer does not hold the address of the first
instruction of a functions implementation. It holds the address
of a function descriptor. Hence the user(), btrap(), eintr() and
bintr() prototypes are wrong for getting the actual code address.
2. The logic forces interrupt, trap and exception entry points to
be layed-out contiguously. This can not be achieved on ia64 and is
generally just bad programming.
The MCOUNT_FROMPC_USER macro is used to set the frompc argument to
some kernel address which represents any frompc that falls outside
the kernel text range. The macro can expand to ~0U to bail out in
that case.
The MCOUNT_FROMPC_INTR macro is used to set the frompc argument to
some kernel address to represent a call to a trap or interrupt
handler. This to avoid that the trap or interrupt handler appear to
be called from everywhere in the call graph. The macro can expand
to ~0U to prevent adjusting frompc. Note that the argument is selfpc,
not frompc.
This commit defines the macros on all architectures equivalently to
the original code in sys/libkern/mcount.c. People can take it from
here...
Compile-tested on: alpha, amd64, i386, ia64 and sparc64
Boot-tested on: i386
valid pmap to the pmap functions that require one. Remove the checks for
NULL. (These checks have their origins in the Mach pmap.c that was
integrated into BSD. None of the new code written specifically for
FreeBSD included them.)
compile option. All FreeBSD packet filters now use the PFIL_HOOKS API and
thus it becomes a standard part of the network stack.
If no hooks are connected the entire packet filter hooks section and related
activities are jumped over. This removes any performance impact if no hooks
are active.
Both OpenBSD and DragonFlyBSD have integrated PFIL_HOOKS permanently as well.
of the MCOUNT_ENTER, MCOUNT_EXIT and MCOUNT_DECL defines. Also make
sure there's a prototype of _MCOUNT_DECL(). This allows us to build
a kernel. There are still unresolved symbols, so linking fails.
_mcount() stub when profiling is enabled. Emit this code sequence
for assembly routines as welli (MCOUNT definition in <machine/asm.h>.
We do not pass the GOT entry however as the 4th argument, because it's
not used. The _mcount() stub calls __mcount(), which does the actual
work. Define _MCOUNT_DECL to define __mcount. We do not have an
implementation of mcount(), so we define MCOUNT as empty, but have a
weak alias to _mcount() in _mcount.S.
Note that the _mcount() stub in the kernel is slightly different from
the stub in userland. This is because we do not have to worry about
nested routines in the kernel.
have been rush hour...
While here, move COMPAT_IA32 from opt_global.h to opt_compat.h like on
amd64. Consequently, it's unsafe to use the option in pcb.h. We now
unconditionally have the ia32 specific registers in the PCB.
This commit is untested.
we update the registers. That way we don't have any dirty registers to
worry about and also know that bsp=bspstore, which makes updating the
RSE related registers predictable.
This is not the end of it. We need more validity checks, but for now
this allows us to complete the gdb testsuite without crashing the
kernel.
to allow dumping per-thread machine specific notes. On ia64 we use this
function to flush the dirty registers onto the backingstore before we
write out the PRSTATUS notes.
Tested on: alpha, amd64, i386, ia64 & sparc64
Not tested on: arm, powerpc
The hardware always gives read access for privilege level 0, which
means that we cannot use the hardware access rights and privilege
level in the PTE to test whether there's a change in protection. So,
we save the original vm_prot_t in the PTE as well.
Add pmap_pte_prot() to set the proper access rights and privilege
level on the PTE given a pmap and the requested protection.
The above allows us to compare the protection in pmap_extract_and_hold()
which was missing. While in pmap_extract_and_hold(), add pmap locking.
While here, clean up most (i.e. all but one) PTE macros we inherited
from alpha. They were either unused, used inconsistently, badly named
or simply weren't beneficial. We save the wired and managed state of
the PTE in distinct (bit) fields.
While in pte.h, s/u_int64_t/uint64_t/g
pmap locking obtained from: alc@
feedback & review by: alc@
path. The basic problem is that we cannot set the single stepping flag
directly, because we don't leave the kernel via an interrupt return. So,
we need another way to set the single stepping flag.
The way we do this is by enabling the lower-privilege transfer trap, which
gets raised when we drop the privilege level. However, since we're still
running in kernel space (sec), we're not yet done. We clear the lower-
privilege transfer trap, enable the taken-branch trap and continue exiting
the kernel until we branch into user space.
Given the current code, there's a total of two traps this way before
we can raise SIGTRAP.
after a fork(2) in fork_trampoline(). By moving the epc_syscall_return
label immediately before the call to do_ast() in epc_syscall(), we not
only achieve that but also handle the detour through exception_return
when the frame corresponds to an asynchronous kernel entry. Hence, we
simplified fork_trampoline() as a side-effect.
related to breakpoints and single stepping into SIGTRAP so gdb(1) knows
why the remote target has stopped. In particular, gdb(1) needs to know
if the reason is something of its own doing.
text/data are covered on APs. This enables the kernel to boot on
a 4 way Intel Itanium-2 platform. This has a secondary effect of
keeping the TRs identical on BP and the APs.
reviewed by: marcel@
being defined, define and use a new MD macro, cpu_spinwait(). It only
expands to something on i386 and amd64, so the compiled code should be
identical.
Name of the macro found by: jhb
Reviewed by: jhb
their own directory and module, leaving the MD parts in the MD
area (the MD parts _are_ part of the modules). /dev/mem and /dev/io
are now loadable modules, thus taking us one step further towards
a kernel created entirely out of modules. Of course, there is nothing
preventing the kernel from having these statically compiled.
brings ia64 to parity with alpha, amd64, and i386 in this area.)
- Prevent a race in pmap_find_pte(): If pmap_find_pte() sleeps in
uma_zalloc(), another thread could allocate a pte at the same address.
Instead, sleep at a higher level and retry the lookup before retrying
the allocation.
Reviewed and tested by: marcel@
dereference curthread. It is called only from critical_{enter,exit}(),
which already dereferences curthread. This doesn't seem to affect SMP
performance in my benchmarks, but improves MySQL transaction throughput
by about 1% on UP on my Xeon.
Head nodding: jhb, bmilekic
the thread ID and call db_trace_thread().
Since arm has all the logic in db_stack_trace_cmd(), rename the
new DB_COMMAND function to db_stack_trace to avoid conflicts on
arm.
While here, have db_stack_trace parse its own arguments so that
we can use a more natural radix for IDs. If the ID is not a thread
ID, or more precisely when no thread exists with the ID, try if
there's a process with that ID and return the first thread in it.
This makes it easier to print stack traces from the ps output.
requested by: rwatson@
tested on: amd64, i386, ia64
future:
rename ttyopen() -> tty_open() and ttyclose() -> tty_close().
We need the ttyopen() and ttyclose() for the new generic cdevsw
functions for tty devices in order to have consistent naming.
pmap_protect() and pmap_remove(). In general, they require the lock in
order to modify a page's pv list or flags. In some cases, however,
pmap_protect() can avoid acquiring the lock.
pmap_remove_pages(). (The implementation of pmap_remove_pages() is
optional. If pmap_remove_pages() is unimplemented, the acquisition and
release of the page queues lock is unnecessary.)
Remove spl calls from the alpha, arm, and ia64 pmap_remove_pages().
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
thread X switch to thread X (where X is the TID),
show threads list all threads.
The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.
With this change, ia64 has support for breakpoints.
o ksym_start and ksym_end changed type to vm_offset_t.
o Make debugging support conditional upon KDB instead of DDB.
o Call kdb_enter() instead of breakpoint().
o Remove implementation of Debugger().
o Call kdb_trap() according to the new world order.
unwinder:
o s/db_active/kdb_active/g
o Various s/ddb/kdb/g
o Add support for unwinding from the PCB as well as the trapframe.
Abuse a spare field in the special register set to flag whether
the PCB was actually constructed from a trapframe so that we can
make the necessary adjustments.
md_var.h:
o Add RSE convenience macros.
o Add ia64_bsp_adjust() to add or subtract from BSP while taking
NaT collections into account.
a PCB from a trapframe for purposes of unwinding the stack. The PCB
is used as the thread context and all but the thread that entered the
debugger has a valid PCB.
This function can also be used to create a context for the threads
running on the CPUs that have been stopped when the debugger got
entered. This however is not done at the time of this commit.
in which multiple (presumably different) debugger backends can be
configured and which provides basic services to those backends.
Besides providing services to backends, it also serves as the single
point of contact for any and all code that wants to make use of the
debugger functions, such as entering the debugger or handling of the
alternate break sequence. For this purpose, the frontend has been
made non-optional.
All debugger requests are forwarded or handed over to the current
backend, if applicable. Selection of the current backend is done by
the debug.kdb.current sysctl. A list of configured backends can be
obtained with the debug.kdb.available sysctl. One can enter the
debugger by writing to the debug.kdb.enter sysctl.
backend improves over the old GDB support in the following ways:
o Unified implementation with minimal MD code.
o A simple interface for devices to register themselves as debug
ports, ala consoles.
o Compression by using run-length encoding.
o Implements GDB threading support.
bootp -> BOOTP
bootp.nfsroot -> BOOTP_NFSROOT
bootp.nfsv3 -> BOOTP_NFSV3
bootp.compat -> BOOTP_COMPAT
bootp.wired_to -> BOOTP_WIRED_TO
- i.e. back out the previous commit. It's already possible to
pxeboot(8) with a GENERIC kernel.
Pointed out by: dwmalone
has outlined which break numbers are software interrupts, debugger
breakpoints and ABI specific breaks. We mostly treated all break
numbers we didn't care about as debugger breakpoints.
BOOTP -> bootp
BOOTP_NFSROOT -> bootp.nfsroot
BOOTP_NFSV3 -> bootp.nfsv3
BOOTP_COMPAT -> bootp.compat
BOOTP_WIRED_TO -> bootp.wired_to
This lets you PXE boot with a GENERIC kernel by putting this sort of thing
in loader.conf:
bootp="YES"
bootp.nfsroot="YES"
bootp.nfsv3="YES"
bootp.wired_to="bge1"
or even setting the variables manually from the OK prompt.
than as one-off hacks in various other parts of the kernel:
- Add a function maybe_preempt() that is called from sched_add() to
determine if a thread about to be added to a run queue should be
preempted to directly. If it is not safe to preempt or if the new
thread does not have a high enough priority, then the function returns
false and sched_add() adds the thread to the run queue. If the thread
should be preempted to but the current thread is in a nested critical
section, then the flag TDF_OWEPREEMPT is set and the thread is added
to the run queue. Otherwise, mi_switch() is called immediately and the
thread is never added to the run queue since it is switch to directly.
When exiting an outermost critical section, if TDF_OWEPREEMPT is set,
then clear it and call mi_switch() to perform the deferred preemption.
- Remove explicit preemption from ithread_schedule() as calling
setrunqueue() now does all the correct work. This also removes the
do_switch argument from ithread_schedule().
- Do not use the manual preemption code in mtx_unlock if the architecture
supports native preemption.
- Don't call mi_switch() in a loop during shutdown to give ithreads a
chance to run if the architecture supports native preemption since
the ithreads will just preempt DELAY().
- Don't call mi_switch() from the page zeroing idle thread for
architectures that support native preemption as it is unnecessary.
- Native preemption is enabled on the same archs that supported ithread
preemption, namely alpha, i386, and amd64.
This change should largely be a NOP for the default case as committed
except that we will do fewer context switches in a few cases and will
avoid the run queues completely when preempting.
Approved by: scottl (with his re@ hat)
to <sys/gmon.h>. Cleaned them up a little by not attempting to ifdef
for incomplete and out of date support for GUPROF in userland, as in
the sparc64 version.
remove the empty line between the fdc and sio devices. The empty
line suggests that the comment applies to fdc only while it applies
to all following devices and options.
Typo spotted by: ru@
gets the relocation base passed in relocbase, we cannot declare a
local variable with the same name. Assume the argument holds the
same value as the local variable did...
elf_reloc() backends for two reasons. First, to support the possibility
of there being two elf linkers in the kernel (eg: amd64), and second, to
pass the relocbase explicitly (for relocating .o format kld files).
the kernel. We can guarantee this by resetting the FP status register.
This masks all FP traps. The reason we did get FP traps was that we
didn't reset the FP status register in all cases.
Make sure to reset the FP status register in syscall(). This is one of
the places where it was forgotten.
While on the subject, reset the FP status register only when we trapped
from user space.
individual asm versions. The global lock is shared between the BIOS and
OS and thus cannot use our mutexes. It is defined in section 5.2.9.1 of
the ACPI specification.
Reviewed by: marcel, bde, jhb
o Fix and improve comments and references,
o Add PFIL_HOOKS, UFS_ACL and UFS_DIRHASH,
o Switch from SCHED_4BSD to SCHED_ULE,
o Remove SCSI_DELAY (there's no SCSI support),
move its declaration to the machine-dependent header file on those
machines that use it. In principle, only i386 should have it.
Alpha and AMD64 should use their direct virtual-to-physical mapping.
- Remove pmap_kenter_temporary() from ia64. It is unused. Approved
by: marcel@
distinguish between debugger inserted breakpoints and fixed
breakpoints. While here, make sure the break instruction never
ends up in the last slot of a bundle by forcing it to be an
M-unit instruction. This makes it easier for use to skip over
it.
level of abstraction for any and all CPU mask and CPU bitmap variables
so that platforms have the ability to break free from the hard limit
of 32 CPUs, simply because we don't have more bits in an u_int. Note
that the type is not supposed to solve massive parallelism, where
the number of CPUs can be larger than the width of the widest integral
type. As such, cpumask_t is not supposed to be a compound type. If
such would be necessary in the future, we can deal with the issues
then and there. For now, it can be assumed that the type is integral
and unsigned.
With this commit, all MD definitions start off as u_int. This allows
us to phase-in cpumask_t at our leasure without breaking anything.
Once cpumask_t is used consistently, platforms can switch to wider
(or smaller) types if such would be beneficial (or not; whatever :-)
Compile-tested on: i386
for uart(4) to figure out which device to use as console. Use this file
to define hw.uart.console instead so that we don't have to put it in
the default loader.conf, which makes it hard to override.
dependent function by the same name and a machine-independent function,
sf_buf_mext(). Aside from the virtue of making more of the code machine-
independent, this change also makes the interface more logical. Before,
sf_buf_free() did more than simply undo an sf_buf_alloc(); it also
unwired and if necessary freed the page. That is now the purpose of
sf_buf_mext(). Thus, sf_buf_alloc() and sf_buf_free() can now be used
as a general-purpose emphemeral map cache.
based on the Madison core and targeting the low end of the spectrum.
Its clock frequency is 1Ghz, whereas Madison starts at 1.3Ghz. Since
the CPUID information is the same for Madison and Deerfield, we use
the clock frequency to identify the processor.
Supposedly the Deerfield only uses 62W, which seems to be less than
modern Xeon processors (about 70W) and about half what a Madison would
need.
ever since alpha/alpha/pmap.c revision 1.81 introduced the list allpmaps,
there has been no reason for having this function on Alpha. Briefly,
when pmap_growkernel() relied upon the list of all processes to find and
update the various pmaps to reflect a growth in the kernel's valid
address space, pmap_init2() served to avoid a race between pmap
initialization and pmap_growkernel(). Specifically, pmap_pinit2() was
responsible for initializing the kernel portions of the pmap and
pmap_pinit2() was called after the process structure contained a pointer
to the new pmap for use by pmap_growkernel(). Thus, an update to the
kernel's address space might be applied to the new pmap unnecessarily,
but an update would never be lost.
with a memory mapped I/O range that's immediately before it and is
not 256MB aligned. As a result, when an address is accessed in the
memory mapped range and a direct mapping is added for it, it overlaps
with the pre-mapped I/O port space and causes a machine check.
Based on a patch from: arun@
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
Add missing D_TTY flags to various drivers.
Complete asserts that dev_t's passed to ttyread(), ttywrite(),
ttypoll() and ttykqwrite() have (d_flags & D_TTY) and a struct tty
pointer.
Make ttyread(), ttywrite(), ttypoll() and ttykqwrite() the default
cdevsw methods for D_TTY drivers and remove the explicit initializations
in various drivers cdevsw structures.
Free approx 86 major numbers with a mostly automatically generated patch.
A number of strategic drivers have been left behind by caution, and a few
because they still (ab)use their major number.
Previously the "struct disk" were owned by the device driver and this
gave us problems when the device disappared and the users of that device
were not immediately disappearing.
Now the struct disk is allocate with a new call, disk_alloc() and owned
by geom_disk and just abandonned by the device driver when disk_create()
is called.
Unfortunately, this results in a ton of "s/\./->/" changes to device
drivers.
Since I'm doing the sweep anyway, a couple of other API improvements
have been carried out at the same time:
The Giant awareness flag has been flipped from DISKFLAG_NOGIANT to
DISKFLAG_NEEDSGIANT
A version number have been added to disk_create() so that we can detect,
report and ignore binary drivers with old ABI in the future.
Manual page update to follow shortly.
o For traps, the cr.iip register points to the next instruction to
execute on interrupt return (modulo slot). Since we need to get
the bundle of the instruction that caused the FP fault/trap, make
sure we fetch the previous bundle if the next instruction is in
fact the first in a bundle.
o When we call the FPSWA handler, we need to tell it whether it's
a trap or a fault (first argument). This was hardcoded to mean a
fault.
Also, for FP faults, when a fault is converted to a trap, adjust the
cr.iip and cr.ipsr registers to point to the next instruction. This
makes sure that the SIGFPE handler gets a consistent state.
at it, use the ANSI C generic pointer type for the second argument,
thus matching the documentation.
Remove the now extraneous (and now conflicting) function declarations
in various libc sources. Remove now unnecessary casts.
Reviewed by: bde
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.
Reviewed by: deischen, dfr
eventually be passed an async. context as well as a syscall
context.
While here, fix a serious bug in that if the trapframe is a
syscall frame, but we're restoring an async context, we need
to clear the FRAME_SYSCALL flag so that we leave the kernel
via exception_restore.
The split-up code is derived from the ia64 code originally.
Note that I have only compile-tested this, not actually run-tested it.
The ia64 side of the force is missing some significant chunks of signal
delivery code.
Not all transfers between kernel and user space are byte oriented
and thus alignment safe. Especially fuword*() and suword*() are
sensitive to alignment but in general more optimal than block copies.
By catching the misalignment trap we avoid pessimizing the common
case of properly aligned memory accesses which we would do if we
were to use byte copies or adding tests for proper alignment.
Note that the expectation that the kernel produces aligned pointers
is unchanged. This change therefore relates to possible unaligned
pointers generated in userland.
as these ioctl's aren't MD. This also means they are installed in
/usr/include/dev/bktr now. Also provide compatability wrappers for
where these headers lived in 4.x.
flags. We now create asynchronous contexts or syscall contexts only.
Syscall contexts differ from the minimal ABI dictated contexts by
having the scratch registers saved and restored because that's where
we keep the syscall arguments and syscall return values.
Since this change affects KSE, have it use kse_switchin(2) for the
"new" syscall context.
very early (SI_SUB_TUNABLES - 1) and is responsible for setting mp_maxid.
cpu_mp_probe() is now called at SI_SUB_CPU and determines if SMP is
actually present and sets mp_ncpus and all_cpus. Splitting these up
allows an architecture to probe CPUs later than SI_SUB_TUNABLES by just
setting mp_maxid to MAXCPU in cpu_mp_setmaxid(). This could allow the
CPU probing code to live in a module, for example, since modules
sysinit's in modules cannot be invoked prior to SI_SUB_KLD. This is
needed to re-enable the ACPI module on i386.
- For the alpha SMP probing code, use LOCATE_PCS() instead of duplicating
its contents in a few places. Also, add a smp_cpu_enabled() function
to avoid duplicating some code. There is room for further code
reduction later since much of this code is also present in cpu_mp_start().
- All archs besides i386 still set mp_maxid to the same values they set it
to before this change. i386 now sets mp_maxid to MAXCPU.
Tested on: alpha, amd64, i386, ia64, sparc64
Approved by: re (scottl)
on SMP systems has a chance of working. This was a loose end of the
implementation of the ACPI Cx idle states. Since our logical CPU Id
is the ACPI processor Id, we do not need to jump through hoops to
obtain it.
Approved: re@ (jhb)
physical mapping.
- Move the sf_buf API to its own header file; make struct sf_buf's
definition machine dependent. In this commit, we remove an
unnecessary field from struct sf_buf on the alpha, amd64, and ia64.
Ultimately, we may eliminate struct sf_buf on those architecures
except as an opaque pointer that references a vm page.
important change is in cpu_switch() where we disable the high FP
registers for the thread that we switch-out if the CPU currently
has its high FP registers. This avoids that the high FP registers
remain enabled for the thread even when the CPU has unloaded them
or the thread migrated to another processor.
Likewise, when we switch-in a thread of that has its high FP
registers on the CPU, we enable them. This avoids an otherwise
harmless, but unnecessary trap to have them enabled.
The code that handles the disabled high FP trap (in trap()) has
been turned into a critical section for the most part to avoid
being preempted. If there's a race, we bail out and have the
processor trap again if necessary.
Avoid using the generic ia64_highfp_save() function when the
context is predictable. The function adds unnecessary overhead.
Don't use ia64_highfp_load() for the same reason. The function
is now unused and can be removed.
These changes make the lazy context switching of the high FP
registers in an UP kernel functional.
that we currently do not keep track of whether the thread has
actually used the high FP registers before. If not, we should
not save them in the context which automaticly means that we
also would not restore them from the context. For now, do it
unconditionally so that we can reach functional completeness.
functions switched to using {g|s}et_mcontext(). The problem is that
sigreturn(), being a syscall, can be given an async. context (i.e.
one corresponding to an interrupt or trap). When this happens, we
try to return to user mode via epc_syscall_return with a trapframe
that can only be used to return to user mode via exception_restore.
To fix this, we check the frame's flags immediately prior to
epc_syscall_return and branch to exception_restore for non-syscall
frames. Modify the assertion in set_mcontext() to check that if
there's a mismatch, it's because of sigreturn().
Only update them in the newly created context to reflect the state
after copying the dirty registers onto the user stack. If we were to
update the trapframe, we lose the state at entry into the kernel. We
may need that after we create the context, such as for KSE upcalls.
We have to update the trapframe after writing the dirty registers to
the user stack for signal delivery to work. But this is best done in
sendsig() itself where it applies, not in get_mcontext() where it's
done unconditionally.
use set_mcontext() to restore the context in sigreturn(). Since we
put the syscall number and the syscall arguments in the trapframe
(we don't save the scratch registers for syscalls, which allows us
to reuse the space to our advantage), create a MD specific flag so
that we save the scratch registers even for syscalls. We would not
be able to restart a syscall otherwise.
The signal trampoline does not need to flush the regiters anymore,
because get_mcontext() already handles that. In fact, if we set up
the context correctly, we do not need to have a trampoline at all.
This change however only minimally changes the trampoline code. In
follow-up commits this can be further optimized.
Note that normally we preserve cfm and iip in the trapframe created
by the EPC syscall path when we restore a context in set_mcontext()
because those fields are not normally set for a synchronuous context.
The kernel puts the return address and frame info of the syscall
stub in there. By preserving these fields we hide this detail from
userland which allows us to use setcontext(2) for user created
contexts. However, sigreturn() is commonly called from the trampoline,
which means that if we preserve cfm and iip in all cases, we would
return to the trampoline after the sigreturn(), which means we hit
the safety net: we call exit(2). So, we do not preserve cfm and iip
when we have a synchronous context that also has scratch registers
(the uncommon context created by sendsig() only), under the assumption
that if such a context is created in userland, something special is
going on and the use of cfm and iip is then just another quirk. All
this is invisible in the common case.
Since all callers either passed 0 or 1 for clear_ret, define bit 0 in
the flags for use as clear_ret. Reserve bits 1, 2 and 3 for use by MI
code for possible (but unlikely) future use. The remaining bits are for
use by MD code.
This change is triggered by a need on ia64 to have another knob for
get_mcontext().
are zx1 based machines and they don't particularly like it when we
poke at them with PC legacy code. The atkbd and psm devices were
disabled in the hints file so that one could enable them on machines
that support legacy devices, but that's not really something you can
expect from a first-time installer. This still leaves syscons (sc)
and the vga device, which were enabled by default and wrecking havoc
anyway. We could disable them by default like the atkbd and psm
devices, but there's really no point in pretending we're in a better
shape that way.
sure we handle stacked registers properly by taking into account
that:
1. bspstore points after the frame (due to cover),
2. we need to adjust for intermediate NaT collections.
cr.isr sanity check. We actually encounter insanities, which very
likely means that the insanity check itself is insane. Remove an empty
comment while I'm at it.
An example of useless is bios.h. An example of wrong is msdos.h (due
to the use of long for 32-bit fields).
display.h cannot be removed because it's used by syscons. That header
however has no platform dependency and shouldn't really be here.
Removal if these headers may cause build failures in the ports tree.
It's the ports that need fixing in that case.
Tested with: buildworld, LINT
the RNAT bit index constant. The net effect of this is that there's
no discontinuity WRT NaT collections which greatly simplifies certain
operations. The cost of this is that there can be up to 504 bytes of
unused stack between the true base of the kernel stack and the start
of the RSE backing store. The cost of adjusting the backing store
pointer to keep the RNAT bit index constant, for each kernel entry,
is negligible.
The primary reasons for this change are:
1. Asynchronuous contexts in KSE processes have the disadvantage of
having to copy the dirty registers from the kernel stack onto the
user stack. The implementation we had so far copied the registers
one at a time without calculating NaT collection values. A process
that used speculation would not work. Now that the RNAT bit index
is constant, we can block-copy the registers from the kernel stack
to the user stack without having to worry about NaT collections.
They will be in the right place on the user stack.
2. The ndirty field in the trapframe is now also usable in userland.
This was previously not the case because ndirty also includes the
space occupied by NaT collections. The value could be off by 8,
depending on the discontinuity. Now that the RNAT bit index is
contants, we have exactly the same number of NaT collection points
on the kernel stack as we would have had on the user stack if we
didn't switch backing stores.
3. Debuggers and other applications that use ptrace(2) can now copy
the dirty registers from the kernel stack (using ptrace(2)) and
copy them whereever they want them (onto the user stack of the
inferior as might be the case for gdb) without having to worry
about NaT collections in the same way the kernel doesn't have to
worry about them.
There's a second order effect caused by the randomization of the
base of the backing store, for it depends on the number of dirty
registers the processor happened to have at the time of entry into
the kernel. The second order effect is that the RSE will have a
better cache utilization as compared to having the backing store
always aligned at page boundaries. This has not been measured and
may be in practice only minimally beneficial, if at all measurable.
license. Only clause 3 has been revoked. Restore the fourth clause
as clause 3.
Pointed out by: das@
Remove my name as a copyright holder since I don't use a BSD license
compatible or comparable to the UCB license. I choose not to add a
complete second license for my work for aesthetic reasons, nor to
replace the UCB license on grounds of rewriting more than 90% of the
source files. The rewrite can also be seen as an enhancement and since
the files were practically empty, it's rather trivial to have changed
90% of the files.
added for XFree86. There are 2 reasons for doing this with sysarch():
1. The memory mapped I/O space is not at a fixed physical address. An
application has to use some interface to get the base address. It
gets worse if the machine has multiple memory mapped I/O spaces.
2. Access to the memory mapped I/O space needs to happen through a
translation that is flagged as uncachable. There's no interface
that allows a process to do uncached memory I/O, other than though
/dev/mem (possibly).
So, until we either disallow direct access to I/O or bus space from
userland or have a better way of doing this, sysarch() has the least
negative impact on existing interfaces.
overlapping TR/TC entries (which results in a machine check). Note
that we don't look at the size of the memory descriptor, because
it doesn't guarantee non-overlap.
With this change, a UP kernel could boot on a Intel Tiger4 machine
with the following options:
options LOG2_ID_PAGE_SIZE=26 # 64M
options LOG2_PAGE_SIZE=14 # 16K
Approved by: marcel
we had were bogus.
While here, reassign the copyright to the Project. There's nothing
in this files that originates from NetBSD, especially now that the
FreeBSD/alpha bits have been removed, but even then the amount of
inherited code that we actually used was nil.
mcontext_t for the register values. Currently only ld8 and ldfd
instructions are handled as those are the ones we need now (a
misaligned ld8 occurs 4 times in ntpd(8) and a misaligned ldfd
occurs once in mozilla 1.4 and 1.5). Other instructions are added
when needed.
at the first address and spills it to the second address. This
allows unaligned_fixup() to update the context of the process in
a way that assures proper rounding.
Similar functions for single-and extended-precision are added when
needed.
in that it provides an abstract (intermediate) representation for
instructions. This significantly improves working with instructions
such as emulation of instructions that are not implemented by the
hardware (e.g. long branch) or enhancing implemented instructions
(e.g. handling of misaligned memory accesses). Not to mention that
it's much easier to print instructions.
Functions are included that provide a textual representation for
opcodes, completers and operands.
The disassembler supports all ia64 instructions defined by revision
2.1 of the SDM (Oct 2002).
by libguile that needs to know the base of the RSE backing store. We
currently do not export the fixed address to userland by means of a
sysctl so user code needs to hardcode it for now. This will be revisited
later.
The RSE backing store is now at the bottom of region 4. The memory stack
is at the top of region 4. This means that the whole region is usable
for the stacks, giving a 61-bit stack space.
Port: lang/guile (depended of x11/gnome2)
halt state that minimizes power consumption while still preserving
cache and TLB coherency. Halting the processor is not conditional at
this time. Tested with UP and SMP kernels.
from UWX_REG_MUMBLE to UWX_REG_AR_MUMBLE. Compatibility defines are
present in libuwx. Change the names here so that we don't depend on
compatibility defines.
Note that there's now an UWX_REG_PFS and an UWX_REG_AR_PFS and the
former is not a compatibility define for the latter AFAICT. Change
to UWX_REG_AR_PFS as that seems to be the one we need to handle.
A small helper function pmap_is_prefaultable() is added. This function
encapsulate the few lines of pmap_prefault() that actually vary from
machine to machine. Note: pmap_is_prefaultable() and pmap_mincore() have
much in common. Going forward, it's worth considering their merger.
frame marker) and the syscall stub frame info in the trap frame.
Previously we stored the stub frame info in (rp,pfs) and the
caller frame info in (iip,cfm). This ends up being suboptimal
for the following reasons:
1. When we create a new context, such as for an execve(2), we had
to set the (rp,pfs) pair for the entry point when using the
syscall path out of the kernel but we need to set the (iip,cfm)
pair when we take the interrupt way out. This is mostly just
an inconsistency from the kernel's point of view, but an ugly
irregularity from gdb(1)'s point of view.
2. The getcontext(2) and setcontext(2) syscalls had to swap the
(rp,pfs) and (iip,cfm) pairs to make the context compatible
with one created purely in userland.
Swapping the (rp,pfs) and (iip,cfm) pairs is visible to signal
handlers that actually peek at the mcontext_t and to gdb(1).
Since this change is made for gdb(1) and we don't care about
signal handlers that peek at the mcontext_t because we're still
a tier 2 platform, this ABI breakage is academic at this moment
in time.
Note that there was no real reason to save the caller frame info
in (iip,cfm) and the stub frame info in (rp,pfs).
about because we're still tier 2 and our current compiler, as well
as future compilers will not support varargs. This is mostly a
no-op in practice, because <sys/varargs.h> should already cause
compile failures.
systems where the data/stack/etc limits are too big for a 32 bit process.
Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.
Supply an ia32_fixlimits function. Export the clip/default values to
sysctl under the compat.ia32 heirarchy.
Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable. This allows mmap to
place mappings at sensible locations when limits have been reduced.
Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.
Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'. And that causes exec etc to fail since it can no
longer find space to mmap things.
not guaranteed that the RSE writes the NaT collection immediately,
sort of atomically, to the backing store when it writes the register
immediately prior to the NaT collection point. This means that we
cannot assume that the low 9 bits of the backingstore pointer do not
point to the NaT collection. This is rather a surprise and I don't
know at this time if it's a bug in the Merced or that it's actually
a valid condition of the architecture. A quick scan over the sources
does not indicate that we depend on the false assumption elsewhere,
but it's something to keep in mind.
The fix is to write the saved contents of the ar.rnat register to
the backingstore prior to entering the loop that copies the dirty
registers from the kernel stack to the user stack.
functions reference UMA internals from <vm/uma_int.h>, which makes
them highly unwanted in non-UMA specific files.
While here, prune the includes in pmap.c and use __FBSDID(). Move
the includes above the descriptive comment.
The copyright of uma_machdep.c is assigned to the project and can
be reassigned to the foundation if and when when such is preferrable.
restart instruction bits in the PSR. As such, we were returning
from interrupt to the instruction in the bundle that caused us
to enter the kernel, only now we're returning to a completely
different bundle.
While close here: add two KASSERTs to make sure that we restore
sync contexts only when entered the kernel through a syscall and
restore an async context only when entered the kernel through an
interrupt, trap or fault.
While not exactly here, but close enough: use suword64() when we
copy the dirty registers from the kernel stack to the user stack.
The code was intended to be be replaced shortly after being added,
but that was a couple of weeks ago. I might as well avoid that it
is a source for panics until it's replaced.
can get (or not) and what we do with them. This fixes the behaviour
for NaT consumption and speculation faults in that we now don't panic
for user faults.
Remove the dopanic label and move the code to a function. This makes
it easier in the simulator to set a breakpoint.
While here, remove the special handling of the old break-based syscall
path and move it to where we handle the break vector. While here,
reserve a new break immediate for KSE. We currently use the old break-
based syscall to deal with restoring async contexts. However, it has
the side-effect of also setting the signal mask and callong ast() on
the way out. The new break immediate simply restores the context and
returns without calling ast().
but for CPL != 0. For some reason yet unknown it is possible for the
CPL to be 2. This would previously be counted as kernel mode, which
resulted in nasty panics. By changing the test it is now treated as
user mode, which is more correct. We still need to figure out how it
is possible that the privilege level can be 2 (or 1 for that matter),
because it's not used by us. We only use 3 (user mode) and 0 (kernel
mode).
we think is the correct trigger mode and polarity. This allows us to
implement BUS_CONFIG_INTR() as an update of the RTE in question.
Consequently, we can trust the RTE when we enable an interrupt and
avoids that we need to know about the trigger mode and polarity at
that time.
latter is a kernel option for IA64_ID_PAGE_SHIFT, which in turn
determines IA64_ID_PAGE_MASK and IA64_ID_PAGE_SIZE.
The constants are used instead of the literal hardcoding (in its
various forms) of the size of the direct mappings created in region
6 and 7. The default and probably only workable size is still 256M,
but for kicks we use 128M for LINT.
atomically extracts and holds the physical page that is associated with the
given pmap and virtual address. Such a function is needed to make the
memory mapping optimizations used by, for example, pipes and raw disk I/O
MP-safe.
Reviewed by: tegge
rl(4) driver and put it in a new re(4) driver. The re(4) driver shares
the if_rlreg.h file with rl(4) but is a separate module. (Ultimately
I may change this. For now, it's convenient.)
rl(4) has been modified so that it will never attach to an 8139C+
chip, leaving it to re(4) instead. Only re(4) has the PCI IDs to
match the 8169/8169S/8110S gigE chips. if_re.c contains the same
basic code that was originally bolted onto if_rl.c, with the
following updates:
- Added support for jumbo frames. Currently, there seems to be
a limit of approximately 6200 bytes for jumbo frames on transmit.
(This was determined via experimentation.) The 8169S/8110S chips
apparently are limited to 7.5K frames on transmit. This may require
some more work, though the framework to handle jumbo frames on RX
is in place: the re_rxeof() routine will gather up frames than span
multiple 2K clusters into a single mbuf list.
- Fixed bug in re_txeof(): if we reap some of the TX buffers,
but there are still some pending, re-arm the timer before exiting
re_txeof() so that another timeout interrupt will be generated, just
in case re_start() doesn't do it for us.
- Handle the 'link state changed' interrupt
- Fix a detach bug. If re(4) is loaded as a module, and you do
tcpdump -i re0, then you do 'kldunload if_re,' the system will
panic after a few seconds. This happens because ether_ifdetach()
ends up calling the BPF detach code, which notices the interface
is in promiscuous mode and tries to switch promisc mode off while
detaching the BPF listner. This ultimately results in a call
to re_ioctl() (due to SIOCSIFFLAGS), which in turn calls re_init()
to handle the IFF_PROMISC flag change. Unfortunately, calling re_init()
here turns the chip back on and restarts the 1-second timeout loop
that drives re_tick(). By the time the timeout fires, if_re.ko
has been unloaded, which results in a call to invalid code and
blows up the system.
To fix this, I cleared the IFF_UP flag before calling ether_ifdetach(),
which stops the ioctl routine from trying to reset the chip.
- Modified comments in re_rxeof() relating to the difference in
RX descriptor status bit layout between the 8139C+ and the gigE
chips. The layout is different because the frame length field
was expanded from 12 bits to 13, and they got rid of one of the
status bits to make room.
- Add diagnostic code (re_diag()) to test for the case where a user
has installed a broken 32-bit 8169 PCI NIC in a 64-bit slot. Some
NICs have the REQ64# and ACK64# lines connected even though the
board is 32-bit only (in this case, they should be pulled high).
This fools the chip into doing 64-bit DMA transfers even though
there is no 64-bit data path. To detect this, re_diag() puts the
chip into digital loopback mode and sets the receiver to promiscuous
mode, then initiates a single 64-byte packet transmission. The
frame is echoed back to the host, and if the frame contents are
intact, we know DMA is working correctly, otherwise we complain
loudly on the console and abort the device attach. (At the moment,
I don't know of any way to work around the problem other than
physically modifying the board, so until/unless I can think of a
software workaround, this will have do to.)
- Created re(4) man page
- Modified rlphy.c to allow re(4) to attach as well as rl(4).
Note that this code works for the sample 8169/Marvell 88E1000 NIC
that I have, but probably won't work for the 8169S/8110S chips.
RealTek has sent me some sample NICs, but they haven't arrived yet.
I will probably need to add an rlgphy driver to handle the on-board
PHY in the 8169S/8110S (it needs special DSP initialization).
ia64_count_cpus() and ia64_probe_sapics() called a single function
to do the the actual work. The difference in behaviour was handled
in that function and was further complicated by adding bootverbose
related code. As such, even the simplest of changes was hard to
comprehend.
Untangling has been done by increasing code duplication and using
a more naive style of coding. FWIW, the object file is slightly
smaller than before, so things aren't as bad as it may seem.
Triggered by: a simple fix on the P4 branch that never got merged.
we return to kernel or userland. This triggered a panic in a KSE
application when TDF_USTATCLOCK was set in the case userland was
interrupted, but we never called ast() on our way out. As such,
we called ast() at some other time. Unfortunately, TDF_USTATCLOCK
handling assumes running in the interrupt thread. This was not
the case anymore.
To avoid making the same mistake later, interrupt() now returns
to its caller whether we interrupted userland or not. This avoids
that we have to duplicate the check in assembly, where it's bound
to fall off the scope. Now we simply check the return value and
call ast() if appropriate.
Run into this: davidxu
it in the last chunk (phys_avail block). The last chunk very often is
not larger than one or two pages, resulting in a msgbuf that's too
small to hold a complete verbose boot.
Note that pmap_steal_memory() will bzero the memory it "allocates".
Consequently, ia64 will never preserve previous msgbufs. This is not
a noticable difference in practice. If the msgbuf could be reused,
it was invariably too small to have anything preserved anyway.
sockets into machine-dependent files. The rationale for this
migration is illustrated by the modified amd64 allocator. It uses the
amd64's direct map to avoid emphemeral mappings in the kernel's
address space. On an SMP, the emphemeral mappings result in an IPI
for TLB shootdown for each transmitted page. Yuck.
Maintainers of other 64-bit platforms with direct maps should be able
to use the amd64 allocator as a reference implementation.
ultimate trigger for the follow-up fixes in revisions 1.78, 1.80,
1.81 and 1.82 of trap.c. I was simply too pre-occupied with the
gateway page and how it blurs kernel space with user space and
vice versa that I couldn't see that it was all a load of bollocks.
It's not the IP address that matters, it's the privilege level that
counts. We never run in user space with lifted permissions and we
sure can not run in kernel space without it. Sure, the gateway page
is the exception, but not if you look at the privilege level. It's
user space if you run with user permissions and kernel space otherwise.
So, we're back to looking at the privilege level like it should be.
There's no other way.
Pointy hat: marcel
prototypes of cpu_halt(), cpu_reset() and swi_vm() from md_var.h to
cpu.h. This affects db_command.c and kern_shutdown.c.
ia64: move all MD prototypes from cpu.h to md_var.h. This affects
madt.c, interrupt.c and mp_machdep.c. Remove is_physical_memory().
It's not used (vm_machdep.c).
alpha: the MD prototypes have been left in cpu.h with a comment
that they should be there. Moving them is left for later. It was
expected that the impact would be significant enough to be done in
a seperate commit.
powerpc: MD prototypes left in cpu.h. Comment added.
Suggested by: bde
Tested with: make universe (pc98 incomplete)
Sign extension happens after the shift, not before so that boundary
cases like 0x40000000 will not be caught properly.
Instead, right shift ndirty. It is guaranteed to be a multiple of 8.
While here, do some manual code motion and code commoning.
Range check bug pointed out by: iedowse
that were on the kernel stack into account. For now we write them
out to the register stack of the process before creating the dump.
This however is not the final solution. The problem is that we may
invalidate the coredump by overwriting vital information due to an
invalid backing store pointer. Instead we need to write the dirty
registers to an unused region of VM which will result in a seperate
segment in the coredump. For now we can at least get to all the
registers from a coredump.
and the move to control register to avoid dependency violations when
these functions are used. Note that explicit data and instruction
serialization also need to be in a subsequent instruction group.
This too requires that we have an igrp break here.
PT_SETKSTACK. These requests allow the tracing process to access the
dirty registers of the traced process that are on the kernel stack.
Note that there's currently no way to access the rnat register for
those dirty registers that are not (yet) covered by a nat collection
point. The interface for this is still being slept on.
Also note that implied by these requests is the division of work:
The tracing process has to keep track of where registers are spilled
and is responsible to figure out where the NaT bit of the stacked
registers are at any time during the execution of the traced process.
The kernel provides the interfaces but will not abstract the fact
that the register stack can be split. This model does not follow
the approach taken in Linux where PT_PEEK and PT_POKE deals with
this automagically.
in user space or kernel space. VM_MIN_KERNEL_ADDRESS starts after the
gateway page, which means that improper memory accesses to the gateway
page while in user mode would panic the kernel. Use VM_MAX_ADDRESS
instead. It ends before the gateway page. The difference between
VM_MIN_KERNEL_ADDRESS and VM_MAX_ADDRESS is exactly the gateway page.
