The implementation comes from Zach's [RFC, PATCH 10/24] i386 Vmi
descriptor changes:

Descriptor and trap table cleanups.  Add cleanly written accessors for
IDT and GDT gates so the subarch may override them.  Note that this
allows the hypervisor to transparently tweak the DPL of the descriptors
as well as the RPL of segments in those descriptors, with no unnecessary
kernel code modification.  It also allows the hypervisor implementation
of the VMI to tweak the gates, allowing for custom exception frames or
extra layers of indirection above the guest fault / IRQ handlers.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>

And add proper CFI annotation to it which was previously
impossible. This prevents "stuck" messages by the dwarf2 unwinder
when reaching the top of a kernel stack.

Includes feedback from Jan Beulich

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

enable_local_apic can now become static.

Cc: len.brown@intel.com
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

acpi_force can become static.

Cc: len.brown@intel.com
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

It's needed for external debuggers and overhead is very small.

Also make the actual notifier chain they use static

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

It's needed for external debuggers and overhead is very small.

Also make the actual notifier chain they use static

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix

linux/arch/i386/kernel/mpparse.c: In function #MP_bus_info#:
linux/arch/i386/kernel/mpparse.c:232: warning: comparison is always false due to limited range of data type
Signed-off-by: NAndi Kleen <ak@suse.de>

Since it's all zero.

Actually I think gcc 4+ will do that automatically, but earlier compilers won't
Signed-off-by: NAndi Kleen <ak@suse.de>

Improve Kconfig description of CONFIG_CRASH_DUMP. Previously
it was too brief to be useful.

Cc: vgoyal@in.ibm.com
Cc: ebiederm@xmission.com
Signed-off-by: NAndi Kleen <ak@suse.de>

I've noticed some erratic behavior while testing the X86_64 version
of monotonic_clock().

While spinning in a loop reading monotonic clock values (pinned to a
single cpu) I noticed that the difference between subsequent values
occasionally went negative (time going backwards).

I found that in the following code:
                this_offset = get_cycles_sync();
                /* FIXME: 1000 or 1000000? */
-->             offset = (this_offset - last_offset)*1000 / cpu_khz;
        }
        return base + offset;

the offset sometimes turns out to be 0, even though
this_offset > last_offset.

+Added fix From: Toyo Abe <toyoa@mvista.com>

The x86_64-mm-monotonic-clock.patch in 2.6.18-rc4-mm2 made a change to
the updating of monotonic_base. It now uses cycles_2_ns().

I suggest that a set_cyc2ns_scale() should be done prior to the setup_irq().
Because cycles_2_ns() can be called from the timer ISR right after the irq0
is enabled.
Signed-off-by: NToyo Abe <toyoa@mvista.com>
Signed-off-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.

AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.

+From: Jeremy Fitzhardinge <jeremy@goop.org>

KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.

Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup.  Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup).  It's
surprising this didn't cause more havok.

The fix is to use .pushsection/.popsection, so this stuff nests
properly.  A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.

+From: Chuck Ebbert <76306.1226@compuserve.com>

Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.

Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

We have a test that looks for invalid pairings of certain athlon/durons
that weren't designed for SMP, and taint accordingly (with 'S') if we find
such a configuration.  However, this test shouldn't fire if there's only
a single CPU present. It's perfectly valid for an SMP kernel to boot on UP
hardware for example.

AK: changed to num_possible_cpus()
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix a very dubious piece of code in
arch/i386/kernel/cpu/common.c:cpu_init().  This clears out %fs and
%gs, but clobbers %eax in the process without telling gcc.  It turns
out that gcc happens to be not using %eax at that point anyway so it
doesn't matter much, but it looks like a bomb waiting to go off.

This does end up saving an instruction, because gcc wants %eax==0 for
the set_debugreg()s below.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Now that stacktrace supports dwarf2 don't force frame pointers for lockdep anymore

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Following x86-64 patches. Reuses code from them in fact.

Convert the standard backtracer to do all output using
callbacks.   Use the x86-64 stack tracer implementation
that uses these callbacks to implement the stacktrace interface.

This allows to use the new dwarf2 unwinder for stacktrace
and get better backtraces.

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

This unifies the standard backtracer and the new stacktrace
in memory backtracer. The standard one is converted to use callbacks
and then reimplement stacktrace using new callbacks.

The main advantage is that stacktrace can now use the new dwarf2 unwinder
and avoid false positives in many cases.

I kept it simple to make sure the standard backtracer stays reliable.

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Needed for use of the unwinder in lockdep, because lockdep runs really
early too.

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

Lockdep can call the dwarf2 unwinder early, and the dwarf2 code
uses safe_smp_processor_id which tries to access the local APIC page.
But that doesn't work before the APIC code has set up its fixmap.

Check for this case and always return boot cpu then.

Cc: jbeulich@novell.com
Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

The new dwarf2 unwinder needs to take locks to do backtraces
inside modules. This patch makes sure lockdep which calls
stacktrace is not reentered.

Thanks to Ingo for suggesting this simpler approach.

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

- Remove unused all_contexts parameter
No caller used it
- Move skip argument into the structure (needed for
followon patches)

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

tce_cache_blast_stress was useful during bringup to stress the IOMMU's
cache flushing. Now that we quiesce DMAs on every cache flush, using
_stress() brings the machine down to its knees once you put it under
load. Remove this debug / bringup code that isn't useful anymore
completely.
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Introduce new function verify_bit_range(). Define two versions, one
for CONFIG_IOMMU_DEBUG enabled and one for disabled. Previously we
were checking that the bitmap was consistent every time we allocated
or freed an entry in the TCE table, which is good for debugging but
incurs an unnecessary penalty on non debug builds.
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

is_at_popf() needs to test for the iret instruction as well as
popf.  So add that test and rename it to is_setting_trap_flag().

Also change max insn length from 16 to 15 to match reality.

LAHF / SAHF can't affect TF, so the comment in x86_64 is removed.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

And move one into proto.h

Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>

The combination of "local_save_flags" and "local_irq_disable" seems to be
equivalent to "local_irq_save" (see code snips below). Consequently, replace
occurrences of local_save_flags+local_irq_disable with local_irq_save.

* local_irq_save
#define raw_local_irq_save(flags) \
                do { (flags) = __raw_local_irq_save(); } while (0)

static inline unsigned long __raw_local_irq_save(void)
{
        unsigned long flags = __raw_local_save_flags();

        raw_local_irq_disable();

        return flags;
}

* local_save_flags
#define raw_local_save_flags(flags) \
                do { (flags) = __raw_local_save_flags(); } while (0)
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

Mostly by adding casts.

I didn't touch the "invalid access past ..." which are caused
by the sigset conversion.
Signed-off-by: NAndi Kleen <ak@suse.de>

Fixes

linux/arch/x86_64/mm/fault.c:125:7: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/mm/fault.c:125:7:    expected void [noderef] *<noident><asn:1>
linux/arch/x86_64/mm/fault.c:125:7:    got unsigned char *[assigned] instr
linux/arch/x86_64/mm/fault.c:163:8: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/mm/fault.c:163:8:    expected void [noderef] *<noident><asn:1>
linux/arch/x86_64/mm/fault.c:163:8:    got unsigned char *[assigned] instr
linux/arch/x86_64/mm/fault.c:179:9: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/mm/fault.c:179:9:    expected void [noderef] *<noident><asn:1>
linux/arch/x86_64/mm/fault.c:179:9:    got unsigned long *<noident>
Signed-off-by: NAndi Kleen <ak@suse.de>

Fixes

linux/arch/x86_64/kernel/vsyscall.c:276:7: warning: constant 0x0f40000000000 is so big it is long
linux/arch/x86_64/kernel/vsyscall.c:80:14: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/kernel/vsyscall.c:80:14:    expected void const volatile [noderef] *addr<asn:2>
linux/arch/x86_64/kernel/vsyscall.c:80:14:    got void *<noident>
linux/arch/x86_64/kernel/vsyscall.c:200:7: warning: incorrect type in assignment (different address spaces)
linux/arch/x86_64/kernel/vsyscall.c:200:7:    expected unsigned short [usertype] *map1
linux/arch/x86_64/kernel/vsyscall.c:200:7:    got void [noderef] *<asn:2>
linux/arch/x86_64/kernel/vsyscall.c:203:7: warning: incorrect type in assignment (different address spaces)
linux/arch/x86_64/kernel/vsyscall.c:203:7:    expected unsigned short [usertype] *map2
linux/arch/x86_64/kernel/vsyscall.c:203:7:    got void [noderef] *<asn:2>
linux/arch/x86_64/kernel/vsyscall.c:215:10: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/kernel/vsyscall.c:215:10:    expected void volatile [noderef] *addr<asn:2>
linux/arch/x86_64/kernel/vsyscall.c:215:10:    got unsigned short [usertype] *map2
linux/arch/x86_64/kernel/vsyscall.c:217:10: warning: incorrect type in argument 1 (different address spaces)
linux/arch/x86_64/kernel/vsyscall.c:217:10:    expected void volatile [noderef] *addr<asn:2>
linux/arch/x86_64/kernel/vsyscall.c:217:10:    got unsigned short [usertype] *map1
Signed-off-by: NAndi Kleen <ak@suse.de>

Minor cleanup. Keep setup.c free from unrelated clutter.
Signed-off-by: NAndi Kleen <ak@suse.de>

Move it into srat.c No need to clutter up setup.c for it

And remove use in setup.c completely - it only guarded a printk
which can be done unconditionally.
Signed-off-by: NAndi Kleen <ak@suse.de>

Removes code duplication between i386/x86-64.

Not needed anymore in setup.c since early_param cleanup

Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>

I think it was only needed for the printks and we can do them later.

I put in a single early_printk so that we know the kernel is alive
(early_printk doesn't need any locks)

This makes some things easier for initialization of unwind for
lockdep, which is needed by later patches.

cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Instead of hackish manual parsing

Requires earlier i386 patchkit, but also fixes i386 early_printk again.

I removed some obsolete really early parameters which didn't do anything useful.
Also made a few parameters that needed it early (mostly oops printing setup)

Also removed one panic check that wasn't visible without
early console anyways (the early console is now initialized after that
panic)

This cleans up a lot of code.
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch replaces the open-coded early commandline parsing
throughout the i386 boot code with the generic mechanism (already used
by ppc, powerpc, ia64 and s390).  The code was inconsistent with
whether it deletes the option from the cmdline or not, meaning some of
these will get passed through the environment into init.

This transformation is mainly mechanical, but there are some notable
parts:

1) Grammar: s/linux never set's it up/linux never sets it up/

2) Remove hacked-in earlyprintk= option scanning.  When someone
   actually implements CONFIG_EARLY_PRINTK, then they can use
   early_param().
[AK: actually it is implemented, but I'm adding the early_param it in the next
x86-64 patch]

3) Move declaration of generic_apic_probe() from setup.c into asm/apic.h

4) Various parameters now moved into their appropriate files (thanks Andi).

5) All parse functions which examine arg need to check for NULL,
   except one where it has subtle humor value.

AK: readded acpi_sci handling which was completely dropped
AK: moved some more variables into acpi/boot.c

Cc: len.brown@intel.com
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>