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.
move to ar.rsc. The RSE must be in enforced lazy mode when writing
to RSE modifyable registers. In this case we restore the RSE NaT
collection register ar.rnat. I have seen 2 general exception faults
on pluto1 now that indicate that the move to ar.rsc has already
happened prior to the move to ar.rnat, meaning that the RSE is not
in enforced lazy mode anymore. The ia64 dependency and instruction
ordering rules seem to allow having both registers written to in
the same instruction group, provided ar.rsc is written to later than
ar.rnat (based on the ordering semantics). It appears that we may
be pushing our luck. For now, put them in seperate cycles (by means
of the instruction group break). If we ever get a general exception
fault on the move to ar.rnat again, we have definite proof that
something else is fishy.
o Differentiate between CPU family and CPU model. There are multiple
Itanium 2 models and it's nice to differentiate between them.
o Seperately export the CPU family and CPU model with sysctl.
o Merced is the only model in the Itanium family.
o Add Madison to the Itanium 2 family. We already knew about McKinley.
o Print the CPU family between parenthesis, like we do with the i386
CPU class.
My prototype now identifies itself as:
CPU: Merced (800.03-Mhz Itanium)
pluto1 and pluto2 will eventually identify themselves as:
CPU: McKinley (900.00-Mhz Itanium 2)
magic from exec_setregs(). In set_mcontext() we now also don't have
to worry that we entered the kernel with more that 512 bytes of
dirty registers on the kernel stack. Note that we cannot make any
assumptions anymore WRT to NaT collection points in exec_setregs(),
so we have to deal with them now.
