In long mode the %cs is largely a relic. However there are a few cases
like iret where it matters that we have a valid value. Without this
patch it is possible to enter the kernel in startup_64 without setting
%cs to a valid value. With this patch we don't care what %cs value
we enter the kernel with, so long as the cs shadow register indicates
it is a privileged code segment.
Thanks to Magnus Damm for finding this problem and posting the
first workable patch. I have moved the jump to set %cs down a
few instructions so we don't need to take an extra jump. Which
keeps the code simpler.
Signed-of-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andi Kleen <ak@suse.de>
Based on patch from David Rientjes <rientjes@google.com>, but
changed by AK.
Optimizes the 64-bit hamming weight for x86_64 processors assuming they
have fast multiplication. Uses five fewer bitops than the generic
hweight64. Benchmark on one EMT64 showed ~25% speedup with 2^24
consecutive calls.
Define a new ARCH_HAS_FAST_MULTIPLIER that can be set by other
architectures that can also multiply fast.
When compiling a 64-bit kernel on an Ubuntu 6.06 32bit system (whose GCC is also
a cross-compiler for x86_64) I've seen that head.o is compiled as a 64-bit file
(while it should not) and ld complaining about this during linking:
[AK: it happens on all systems with new binutils]
ld: warning: i386:x86-64 architecture of input file
`arch/x86_64/boot/compressed/head.o' is incompatible with i386 output
I've verified that removing -m64 from compilation flags to turn
"-m64 -traditional -m32" into "-traditional -m32" fixes the issue.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andi Kleen <ak@suse.de>
[PATCH] Remove some cruft in apic id checking during processor setup
- Remove a define that was used only once
- Remove the too large APIC ID check because we always support
the full 8bit range of APICs.
- Restructure code a bit to be simpler.
ACPI went to great trouble to get the APIC version and CPU capabilities
of different CPUs before passing them to the mpparser. But all
that data was used was to print it out. Actually it even faked some data
based on the boot cpu, not on the actual CPU being booted.
[PATCH] Fix pte_exec/mkexec and use it in change_page_attr()
Fix the pte_exec/mkexec page table accessor functions to really
use the NX bit. Previously they only checked the USER bit, but
weren't actually used for anything.
Then use them in change_page_attr() to manipulate the NX bit
properly.
And replace all users with ordinary smp_processor_id. The function
was originally added to get some basic oops information out even
if the GS register was corrupted. However that didn't
work for some anymore because printk is needed to print the oops
and it uses smp_processor_id() already. Also GS register corruptions
are not particularly common anymore.
This also helps the Xen port which would otherwise need to
do this in a special way because it can't access the local APIC.
Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andi Kleen <ak@suse.de>
Detect the situations in which the time after a resume from disk would
be earlier than the time before the suspend and prevent them from
happening on x86_64.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@suse.de>
[PATCH] i386: annotate FIX_STACK() and the rest of nmi()
In i386's entry.S, FIX_STACK() needs annotation because it
replaces the stack pointer. And the rest of nmi() needs
annotation in order to compile with these new annotations.
A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.
Note: This problem was originally spotted and solved by Andi Kleen in the
x86_64 architecture. This patch is an adaption of his patch for i386.
AK: Merged with current code which was a bit different.
AK: Removed printk in nmi handler that shouldn't be there in the first time
AK: Added missing include.
AK: added KPROBES_END
Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.
Note: This problem was originally spotted by Andi Kleen. This patch
adds fixes not included in his original patch.
[AK: Jan Beulich originally discovered these classes of bugs]
Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Magnus Damm [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] i386: mark cpu cache functions as __cpuinit
Mark i386-specific cpu cache functions as __cpuinit. They are all
only called from arch/i386/common.c:display_cache_info() that already is
marked as __cpuinit.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Magnus Damm [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] i386: mark cpu identify functions as __cpuinit
Mark i386-specific cpu identification functions as __cpuinit. They are all
only called from arch/i386/common.c:identify_cpu() that already is marked as
__cpuinit.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Magnus Damm [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] i386: mark cpu init functions as __cpuinit, data as __cpuinitdata
Mark i386-specific cpu init functions as __cpuinit. They are all
only called from arch/i386/common.c:identify_cpu() that already is marked as
__cpuinit. This patch also removes the empty function init_umc().
Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Magnus Damm [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] i386: mark cpu_dev structures as __cpuinitdata
The different cpu_dev structures are all used from __cpuinit callers what
I can tell. So mark them as __cpuinitdata instead of __initdata. I am a
little bit unsure about arch/i386/common.c:default_cpu, especially when it
comes to the purpose of this_cpu.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Magnus Damm [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] i386: remove redundant generic_identify() calls when identifying cpus
cpu_dev->c_identify is only called from arch/i386/common.c:identify_cpu(), and
this after generic_identify() already has been called. There is no need to call
this function twice and hook it in c_identify - but I may be wrong, please
double check before applying.
This patch also removes generic_identify() from cpu.h to avoid unnecessary
future nesting.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
Keith Mannthey [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] x86_64 kernel mapping fix
Fix for the x86_64 kernel mapping code. Without this patch the update path
only inits one pmd_page worth of memory and tramples any entries on it. now
the calling convention to phys_pmd_init and phys_init is to always pass a
[pmd/pud] page not an offset within a page.
Signed-off-by: Keith Mannthey<kmannth@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
Arjan van de Ven [Tue, 26 Sep 2006 08:52:36 +0000 (10:52 +0200)]
[PATCH] non lazy "sleazy" fpu implementation
Right now the kernel on x86-64 has a 100% lazy fpu behavior: after *every*
context switch a trap is taken for the first FPU use to restore the FPU
context lazily. This is of course great for applications that have very
sporadic or no FPU use (since then you avoid doing the expensive
save/restore all the time). However for very frequent FPU users... you
take an extra trap every context switch.
The patch below adds a simple heuristic to this code: After 5 consecutive
context switches of FPU use, the lazy behavior is disabled and the context
gets restored every context switch. If the app indeed uses the FPU, the
trap is avoided. (the chance of the 6th time slice using FPU after the
previous 5 having done so are quite high obviously).
After 256 switches, this is reset and lazy behavior is returned (until
there are 5 consecutive ones again). The reason for this is to give apps
that do longer bursts of FPU use still the lazy behavior back after some
time.
[akpm@osdl.org: place new task_struct field next to jit_keyring to save space] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
[PATCH] i386: Support physical cpu hotplug for x86_64
This patch enables ACPI based physical CPU hotplug support for x86_64.
Implements acpi_map_lsapic() and acpi_unmap_lsapic() to support physical cpu
hotplug.
Now for a completely different but trivial approach.
I just boot tested it with 255 CPUS and everything worked.
Currently everything (except module data) we place in
the per cpu area we know about at compile time. So
instead of allocating a fixed size for the per_cpu area
allocate the number of bytes we need plus a fixed constant
for to be used for modules.
It isn't perfect but it is much less of a pain to
work with than what we are doing now.
AK: fixed warning
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andi Kleen <ak@suse.de>
Rusty Russell [Tue, 26 Sep 2006 08:52:35 +0000 (10:52 +0200)]
[PATCH] i386: Descriptor and trap table cleanups.
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.
[PATCH] i386: move kernel_thread_helper into entry.S
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.
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
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.
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.
Dave Jones [Tue, 26 Sep 2006 08:52:34 +0000 (10:52 +0200)]
[PATCH] i386: don't taint UP K7's running SMP kernels.
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: Dave Jones <davej@redhat.com> Signed-off-by: Andi Kleen <ak@suse.de>
[PATCH] i386: fix dubious segment register clear in cpu_init()
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: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andi 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.
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.
[PATCH] Don't access the APIC in safe_smp_processor_id when it is not mapped yet
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.
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.
[PATCH] only verify the allocation bitmap if CONFIG_IOMMU_DEBUG is on
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.
[PATCH] Replace local_save_flags+local_irq_disable with
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: Fernando Vazquez <fernando@intellilink.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
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)
Rusty Russell [Tue, 26 Sep 2006 08:52:32 +0000 (10:52 +0200)]
[PATCH] i386: Replace i386 open-coded cmdline parsing with
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: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de>
Rusty Russell [Tue, 26 Sep 2006 08:52:32 +0000 (10:52 +0200)]
[PATCH] Allow early_param and identical __setup to exist
We currently assume that boot parameters which are handled by
early_param() will not overlap boot parameters handled by __setup: if
they do, behaviour is dependent on link order, usually meaning __setup
will not get called.
ACPI wants to use early_param("pci"), and pci uses __setup("pci="), so
we modify the core to let them coexist: "pci=noacpi" will now get
passed to both.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de>
[PATCH] remove superflous BUG_ON's in nommu and gart
There's no need to check for invalid DMA data direction in nommu and
gart since we do it in dma-mapping.h anyway before calling the
individual dma-ops.
- Inline spinlock strings into their inline functions
- Convert macros to typesafe inlines
- Replace some leftover __asm__ __volatile__s with asm volatile
- Inline spinlock strings into their inline functions
- Convert macros to typesafe inlines
- Replace some leftover __asm__ __volatile__s with asm volatile
[PATCH] Calgary IOMMU: fix reference counting of Calgary PCI devices
The pci_get_device() API decrements the reference count on the 'from'
parameter when it continues searching. Therefore, take a ref count on
Calgary bus when we initialize them in either translated or
non-translated mode.
[PATCH] Calgary IOMMU: consolidate per bus data structures
Move the tce_table_kva array, disabled bitmap and bus_to_phb array
into a new per bus 'struct calgary_bus_info'. Also slightly reorganize
build_tce_table and tce_table_setparms to avoid exporting bus_info to
tce.c.
Jan Beulich [Tue, 26 Sep 2006 08:52:31 +0000 (10:52 +0200)]
[PATCH] i386: initialize end-of-memory variables as early as possible
Move initialization of all memory end variables to as early as
possible, so that dependent code doesn't need to check whether these
variables have already been set.
Change the range check in kunmap_atomic to actually make use of this
so that the no-mapping-estabished path (under CONFIG_DEBUG_HIGHMEM)
gets used only when the address is inside the lowmem area (and BUG()
otherwise).
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de>
Jan Beulich [Tue, 26 Sep 2006 08:52:31 +0000 (10:52 +0200)]
[PATCH] initialize end of memory variables as early as possible
While an earlier patch already did a small step into that direction,
this patch moves initialization of all memory end variables to as
early as possible, so that dependent code doesn't need to check
whether these variables have already been set.
Also, remove a misleading (perhaps just outdated) comment, and make
static a variable only used in a single file.
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de>
[PATCH] x86: Detect CFI support in the assembler at runtime
... instead of using a CONFIG option. The config option still controls
if the resulting executable actually has unwind information.
This is useful to prevent compilation errors when users select
CONFIG_STACK_UNWIND on old binutils and also allows to use
CFI in the future for non kernel debugging applications.
projects / linux-beck.git / log