Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix boot crash with numcpus=0 on certain systems

Fix early exception in __get_smp_config with nosmp.

Bail out early when there is no MP table.
Reported-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The access to the iommu->need_sync member needs to be protected by the
iommu->lock. Otherwise this is a possible race condition. Fix it with
this patch.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

In some rare cases a request can arrive an IOMMU with its originial
requestor id even it is aliased. Handle this by setting the device table
entry to the same protection domain for the original and the aliased
requestor id.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: remove stale IOTLB entries

In the non-default nofullflush case the GART is only flushed when
next_bit wraps around. But it can happen that an unmap operation unmaps
memory which is behind the current next_bit location. If these addresses
are reused it may result in stale GART IO/TLB entries. Fix this by
setting the GART next_bit always behind an unmapped location.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

calls __init, called only from __init
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A workaround for AMD CPU family 11h erratum 311 might cause that the
P-state Status Register shows a "current P-state" which is larger than
the "current P-state limit" in P-state Current Limit Register. For the
wrong P-state value there is no ACPI _PSS object defined and
powernow-k8/cpufreq can't determine the proper CPU frequency for that
state.

As a consequence this can cause a panic during boot (potentially with
all recent kernel versions -- at least I have reproduced it with
various 2.6.27 kernels and with the current .28 series), as an
example:

powernow-k8: Found 1 AMD Turion(tm)X2 Ultra DualCore Mobile ZM-82 processors (2 \
)
powernow-k8:    0 : pstate 0 (2200 MHz)
powernow-k8:    1 : pstate 1 (1100 MHz)
powernow-k8:    2 : pstate 2 (600 MHz)
BUG: unable to handle kernel paging request at ffff88086e7528b8
IP: [<ffffffff80486361>] cpufreq_stats_update+0x4a/0x5f
PGD 202063 PUD 0
Oops: 0002 [#1] SMP
last sysfs file:
CPU 1
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.28-rc3-dirty #16
RIP: 0010:[<ffffffff80486361>]  [<ffffffff80486361>] cpufreq_stats_update+0x4a/0\
f
Synaptics claims to have extended capabilities, but I'm not able to read them.<6\
6
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88006e7528c0
RDX: 00000000ffffffff RSI: ffff88006e54af00 RDI: ffffffff808f056c
RBP: 00000000fffee697 R08: 0000000000000003 R09: ffff88006e73f080
R10: 0000000000000001 R11: 00000000002191c0 R12: ffff88006fb83c10
R13: 00000000ffffffff R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88006fb50740(0000) knlGS:0000000000000000
Unable to initialize Synaptics hardware.
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: ffff88086e7528b8 CR3: 0000000000201000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff88006fb82000, task ffff88006fb816d0)
Stack:
 ffff88006e74da50 0000000000000000 ffff88006e54af00 ffffffff804863c7
 ffff88006e74da50 0000000000000000 00000000ffffffff 0000000000000000
 ffff88006fb83c10 ffffffff8024b46c ffffffff808f0560 ffff88006fb83c10
Call Trace:
 [<ffffffff804863c7>] ? cpufreq_stat_notifier_trans+0x51/0x83
 [<ffffffff8024b46c>] ? notifier_call_chain+0x29/0x4c
 [<ffffffff8024b561>] ? __srcu_notifier_call_chain+0x46/0x61
 [<ffffffff8048496d>] ? cpufreq_notify_transition+0x93/0xa9
 [<ffffffff8021ab8d>] ? powernowk8_target+0x1e8/0x5f3
 [<ffffffff80486687>] ? cpufreq_governor_performance+0x1b/0x20
 [<ffffffff80484886>] ? __cpufreq_governor+0x71/0xa8
 [<ffffffff80484b21>] ? __cpufreq_set_policy+0x101/0x13e
 [<ffffffff80485bcd>] ? cpufreq_add_dev+0x3f0/0x4cd
 [<ffffffff8048577a>] ? handle_update+0x0/0x8
 [<ffffffff803c2062>] ? sysdev_driver_register+0xb6/0x10d
 [<ffffffff8056592c>] ? powernowk8_init+0x0/0x7e
 [<ffffffff8048604c>] ? cpufreq_register_driver+0x8f/0x140
 [<ffffffff80209056>] ? _stext+0x56/0x14f
 [<ffffffff802c2234>] ? proc_register+0x122/0x17d
 [<ffffffff802c23a0>] ? create_proc_entry+0x73/0x8a
 [<ffffffff8025c259>] ? register_irq_proc+0x92/0xaa
 [<ffffffff8025c2c8>] ? init_irq_proc+0x57/0x69
 [<ffffffff807fc85f>] ? kernel_init+0x116/0x169
 [<ffffffff8020cc79>] ? child_rip+0xa/0x11
 [<ffffffff807fc749>] ? kernel_init+0x0/0x169
 [<ffffffff8020cc6f>] ? child_rip+0x0/0x11
Code: 05 c5 83 36 00 48 c7 c2 48 5d 86 80 48 8b 04 d8 48 8b 40 08 48 8b 34 02 48\

RIP  [<ffffffff80486361>] cpufreq_stats_update+0x4a/0x5f
 RSP <ffff88006fb83b20>
CR2: ffff88086e7528b8
---[ end trace 0678bac75e67a2f7 ]---
Kernel panic - not syncing: Attempted to kill init!

In short, aftereffect of the wrong P-state is that
cpufreq_stats_update() uses "-1" as index for some array in

cpufreq_stats_update (unsigned int cpu)
{
...
     if (stat->time_in_state)
                stat->time_in_state[stat->last_index] =
                        cputime64_add(stat->time_in_state[stat->last_index],
                                      cputime_sub(cur_time, stat->last_time));
...
}

Fortunately, the wrong P-state value is returned only if the core is
in P-state 0. This fix solves the problem by detecting the
out-of-range P-state, ignoring it, and using "0" instead.

Cc: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Impact: fix sleeping-with-spinlock-held bugs/crashes

- Turn a wrmsr to write the DS_AREA MSR into a wrmsrl.
- Use irqsave variants of spinlocks.
- Do not allocate memory while holding spinlocks.
Reported-by: NStephane Eranian <eranian@googlemail.com>
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix DS hw enablement on 64-bit x86

Fix the PEBS record size in the DS configuration.
Reported-by: NStephane Eranian <eranian@googlemail.com>
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Move the CONFIG guard from the .c file into the makefile.
Reported-by: NAndi Kleen <andi-suse@firstfloor.org>
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix theoretical option string parsing overflow

Since bridge is unsigned, it would seem better to use simple_strtoul that
simple_strtol.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r2@
long e;
position p;
@@

e = simple_strtol@p(...)

@@
position p != r2.p;
type T;
T e;
@@

e =
- simple_strtol@p
+ simple_strtoul
  (...)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: muli@il.ibm.com
Cc: jdmason@kudzu.us
Cc: discuss@x86-64.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix MSIx not enough irq numbers available regression

The manual revert of the sparse_irq patches missed to bring the number
of possible irqs back to the .27 status. This resulted in a regression
when two multichannel network cards were placed in a system with only
one IO_APIC - causing the networking driver to not have the right
IRQ and the device not coming up.

Remove the dynamic allocation logic leftovers and simply return
NR_IRQS in probe_nr_irqs() for now.

   Fixes: http://lkml.org/lkml/2008/11/19/354Reported-by: NJesper Dangaard Brouer <hawk@diku.dk>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJesper Dangaard Brouer <hawk@diku.dk>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used.  If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.

This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Annotate xsave_cntxt_init() as "can be called outside of __init".
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact:	fix incorrect __init annotation

This patch removes the following section mismatch warning. A patch set
was send previously (http://lkml.org/lkml/2008/11/10/407). But
introduce some other problem, reported by Rufus
(http://lkml.org/lkml/2008/11/11/46). Then Ingo Molnar suggest that,
it's best to remove __init from xsave_cntxt_init(void). Which is the
second patch in this series. Now, this one removes the following
warning.

WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2237): Section
mismatch in reference from the function cpu_init() to the function
.init.text:init_thread_xstate()
The function __cpuinit cpu_init() references
a function __init init_thread_xstate().
If init_thread_xstate is only used by cpu_init then
annotate init_thread_xstate with a matching annotation.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Dell Optiplex 330 appears to hang on reboot. This is resolved by adding
a quirk to set bios reboot.
Signed-off-by: NLeann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: NSteve Conklin <steve.conklin@canonical.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: widen the reach of the low-memory-protect DMI quirk

Phoenix BIOSes variously identify their vendor as "Phoenix Technologies,
LTD" or "Phoenix Technologies LTD" (without the comma.)

This patch makes the identification string in the bad_bios_dmi_table
more general (following a suggestion by Ingo Molnar), so that both
versions are handled.

Again, the patched file compiles cleanly and the patch has been tested
successfully on my machine.
Signed-off-by: NPhilipp Kohlbecher <xt28@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix possible use of stale IO/TLB entries
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: fix comparison length for 'fullflush'
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: makes device isolation the default for AMD IOMMU

Some device drivers showed double-free bugs of DMA memory while testing
them with AMD IOMMU. If all devices share the same protection domain
this can lead to data corruption and data loss. Prevent this by putting
each device into its own protection domain per default.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: add a new AMD IOMMU kernel command line parameter
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

this compiler warning:

  arch/x86/kernel/ds.c: In function 'ds_request':
  arch/x86/kernel/ds.c:368: warning: 'context' may be used uninitialized in this function

Shows that the code flow in ds_request() is buggy - it goes into
the unlock+release-context path even when the context is not allocated
yet.

First allocate the context, then do the other checks.

Also, take care with GFP allocations under the ds_lock spinlock.

Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix incorrectly marked unstable TSC clock

Patch (commit 0d12cdd5 "sched: improve sched_clock() performance") has
a regression on one of the test systems here.

With the patch, I see:

 checking TSC synchronization [CPU#0 -> CPU#1]:
 Measured 28 cycles TSC warp between CPUs, turning off TSC clock.
 Marking TSC unstable due to check_tsc_sync_source failed

Whereas, without the patch syncs pass fine on all CPUs:

 checking TSC synchronization [CPU#0 -> CPU#1]: passed.

Due to this, TSC is marked unstable, when it is not actually unstable.
This is because syncs in check_tsc_wrap() goes away due to this commit.

As per the discussion on this thread, correct way to fix this is to add
explicit syncs as below?
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix es7000 build

  CC      arch/x86/kernel/es7000_32.o
arch/x86/kernel/es7000_32.c: In function find_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:255: error: implicit declaration of function acpi_get_table_with_size
arch/x86/kernel/es7000_32.c:261: error: implicit declaration of function early_acpi_os_unmap_memory
arch/x86/kernel/es7000_32.c: In function unmap_unisys_acpi_oem_table:
arch/x86/kernel/es7000_32.c:277: error: implicit declaration of function __acpi_unmap_table
make[1]: *** [arch/x86/kernel/es7000_32.o] Error 1

we applied one patch out of order...

| commit a73aaedd
| Author: Yinghai Lu <yhlu.kernel@gmail.com>
| Date:   Sun Sep 14 02:33:14 2008 -0700
|
|    x86: check dsdt before find oem table for es7000, v2
|
|    v2: use __acpi_unmap_table()

that patch need:

	x86: use early_ioremap in __acpi_map_table
	x86: always explicitly map acpi memory
	acpi: remove final __acpi_map_table mapping before setting acpi_gbl_permanent_mmap
	acpi/x86: introduce __apci_map_table, v4

submitted to the ACPI tree but not upstream yet.

fix it until those patches applied, need to revert this one
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix a problem where ds_request() returned an error without releasing the
ds lock.
Reported-by: NStephane Eranian <eranian@gmail.com>
Signed-off-by: NMarkus Metzger <markus.t.metzger@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit e51af663, which was
wrongly hoovered up and submitted about a month after a better fix had
already been merged.

The better fix is commit cbda1ba8
("PCI/iommu: blacklist DMAR on Intel G31/G33 chipsets"), where we do
this blacklisting based on the DMI identification for the offending
motherboard, since sometimes this chipset (or at least a chipset with
the same PCI ID) apparently _does_ actually have an IOMMU.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This removes the acpi_irq_balance_set() interface from the PCI
interrupt link driver.

x86 used acpi_irq_balance_set() to tell the PCI interrupt link
driver to configure links to minimize IRQ sharing.  But the link
driver can easily figure out whether to turn on IRQ balancing
based on the IRQ model (PIC/IOAPIC/etc), so we can get rid of
that external interface.

It's better for the driver to figure this out at init-time.  If
we set it externally via the x86 code, the interface reduces
modularity, and we depend on the fact that acpi_process_madt()
happens before we process the kernel command line.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

WARNING: arch/x86/kernel/built-in.o(.text+0x1722c): Section mismatch
in reference from the function kvm_setup_secondary_clock() to the
function .devinit.text:setup_secondary_APIC_clock()
The function kvm_setup_secondary_clock() references
the function __devinit setup_secondary_APIC_clock().
This is often because kvm_setup_secondary_clock lacks a __devinit
annotation or the annotation of setup_secondary_APIC_clock is wrong.
Signed-off-by: NMd.Rakib H. Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some functions that may be called from this handler require that
interrupts are disabled. Also, combining IRQF_DISABLED and
IRQF_SHARED does not reliably disable interrupts in a handler, so
remove IRQF_SHARED from the irq flags (this irq is not shared anyway).
Signed-off-by: NMatt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Cc: "Will Newton" <will.newton@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

In hpet_next_event() we check that the value we just wrote to
HPET_Tn_CMP(timer) has reached the chip. Currently, we're checking that
the value we wrote to HPET_Tn_CMP(timer) is in HPET_T0_CMP, which, if
timer is anything other than timer 0, is likely to fail.
Signed-off-by: NMatt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

It is possible to flood the console with call traces if the WARN_ON
condition is true because of the frequency with which this function is
called.
Signed-off-by: NMatt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

setup_ioapic_dest() is called after the non boot cpus have been
brought up. It sets the irq affinity of all already configured
interrupts to all cpus and ignores affinity settings which were
done by the early bootup code.

If the IRQ_NO_BALANCING or IRQ_AFFINITY_SET flags are set then use the
affinity mask from the irq descriptor and not TARGET_CPUS.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

sched_clock() uses cycles_2_ns() needlessly - which is an irq-disabling
variant of __cycles_2_ns().

Most of the time sched_clock() is called with irqs disabled already.
The few places that call it with irqs enabled need to be updated.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit c7ffa6c2.

the assumptio of this change was that this would not break
any existing machine. Andrey Borzenkov reported troubles with
the ACPI reboot method: the system would hang on reboot, necessiating
a power cycle. Probably more systems are affected as well.

Also, there are patches queued up for v2.6.29 to disable virtualization
on emergency_restart() - which was the original motivation of
this change.
Reported-by: NAndrey Borzenkov <arvidjaar@mail.ru>
Bisected-by: NAndrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Lazy flushing needs to take care of the unmap path too which is not yet
implemented and leads to stale IO/TLB entries. This is fixed by this
patch.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: fix rare x2apic hang

On x86, x2apic mode accesses for sending IPI's don't have serializing
semantics. If the IPI receivner refers(in lock-free fashion) to some
memory setup by the sender, the need for smp_mb() before sending the
IPI becomes critical in x2apic mode.

Add the smp_mb() in native_flush_tlb_others() before sending the IPI.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix boot hang on 32-bit systems with more than 224 IO-APIC pins

On some 32-bit systems with a lot of IO-APICs probe_nr_irqs() can
return a value larger than NR_IRQS. This will lead to probe_irq_on()
overrunning the irq_desc array.

I hit this when running net-next-2.6 (close to 2.6.28-rc3) on a
Supermicro dual Xeon system.  NR_IRQS is 224 but probe_nr_irqs() detects
5 IOAPICs and returns 240.  Here are the log messages:

Tue Nov  4 16:53:47 2008 ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
Tue Nov  4 16:53:47 2008 IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-23
Tue Nov  4 16:53:47 2008 ACPI: IOAPIC (id[0x02] address[0xfec81000] gsi_base[24])
Tue Nov  4 16:53:47 2008 IOAPIC[1]: apic_id 2, version 32, address 0xfec81000, GSI 24-47
Tue Nov  4 16:53:47 2008 ACPI: IOAPIC (id[0x03] address[0xfec81400] gsi_base[48])
Tue Nov  4 16:53:47 2008 IOAPIC[2]: apic_id 3, version 32, address 0xfec81400, GSI 48-71
Tue Nov  4 16:53:47 2008 ACPI: IOAPIC (id[0x04] address[0xfec82000] gsi_base[72])
Tue Nov  4 16:53:47 2008 IOAPIC[3]: apic_id 4, version 32, address 0xfec82000, GSI 72-95
Tue Nov  4 16:53:47 2008 ACPI: IOAPIC (id[0x05] address[0xfec82400] gsi_base[96])
Tue Nov  4 16:53:47 2008 IOAPIC[4]: apic_id 5, version 32, address 0xfec82400, GSI 96-119
Tue Nov  4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 high edge)
Tue Nov  4 16:53:47 2008 ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
Tue Nov  4 16:53:47 2008 Enabling APIC mode:  Flat.  Using 5 I/O APICs
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Acked-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix udelay when "notsc" boot parameter is passed

With notsc passed on commandline, tsc may not be used for
udelays, make sure that we do not use tsc_khz to calculate
the lpj value in such cases.
Reported-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NAlok N Kataria <akataria@vmware.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This makes the late e820 resources use 'insert_resource_expand_to_fit()'
instead of doing a 'reserve_region_with_split()', and also avoids
marking them as IORESOURCE_BUSY.

This results in us being perfectly happy to use pre-existing PCI
resources even if they were marked as being in a reserved region, while
still avoiding any _new_ allocations in the reserved regions.  It also
makes for a simpler and more accurate resource tree.

Example resource allocation from Jonathan Corbet, who has firmware that
has an e820 reserved entry that covered a big range (e0000000-fed003ff),
and that had various PCI resources in it set up by firmware.

With old kernels, the reserved range would force us to re-allocate all
pre-existing PCI resources, and his reserved range would end up looking
like this:

	e0000000-fed003ff : reserved
	  fec00000-fec00fff : IOAPIC 0
	  fed00000-fed003ff : HPET 0

where only the pre-allocated special regions (IOAPIC and HPET) were kept
around.

With 2.6.28-rc2, which uses 'reserve_region_with_split()', Jonathan's
resource tree looked like this:

	e0000000-fe7fffff : reserved
	fe800000-fe8fffff : PCI Bus 0000:01
	 fe800000-fe8fffff : reserved
	fe900000-fe9d9aff : reserved
	fe9d9b00-fe9d9bff : 0000:00:1f.3
	 fe9d9b00-fe9d9bff : reserved
	fe9d9c00-fe9d9fff : 0000:00:1a.7
	 fe9d9c00-fe9d9fff : reserved
	fe9da000-fe9dafff : 0000:00:03.3
	 fe9da000-fe9dafff : reserved
	fe9db000-fe9dbfff : 0000:00:19.0
	 fe9db000-fe9dbfff : reserved
	fe9dc000-fe9dffff : 0000:00:1b.0
	 fe9dc000-fe9dffff : reserved
	fe9e0000-fe9fffff : 0000:00:19.0
	 fe9e0000-fe9fffff : reserved
	fea00000-fea7ffff : 0000:00:02.0
	 fea00000-fea7ffff : reserved
	fea80000-feafffff : 0000:00:02.1
	 fea80000-feafffff : reserved
	feb00000-febfffff : 0000:00:02.0
	 feb00000-febfffff : reserved
	fec00000-fed003ff : reserved
	 fec00000-fec00fff : IOAPIC 0
	 fed00000-fed003ff : HPET 0

and because the reserved entry had been split and moved into the
individual resources, and because it used the IORESOURCE_BUSY flag, the
drivers that actually wanted to _use_ those resources couldn't actually
attach to them:

	e1000e 0000:00:19.0: BAR 0: can't reserve mem region [0xfe9e0000-0xfe9fffff]
	HDA Intel 0000:00:1b.0: BAR 0: can't reserve mem region [0xfe9dc000-0xfe9dffff]

with this patch, the resource tree instead becomes

	e0000000-fed003ff : reserved
	  fe800000-fe8fffff : PCI Bus 0000:01
	  fe9d9b00-fe9d9bff : 0000:00:1f.3
	  fe9d9c00-fe9d9fff : 0000:00:1a.7
	    fe9d9c00-fe9d9fff : ehci_hcd
	  fe9da000-fe9dafff : 0000:00:03.3
	  fe9db000-fe9dbfff : 0000:00:19.0
	    fe9db000-fe9dbfff : e1000e
	  fe9dc000-fe9dffff : 0000:00:1b.0
	    fe9dc000-fe9dffff : ICH HD audio
	  fe9e0000-fe9fffff : 0000:00:19.0
	    fe9e0000-fe9fffff : e1000e
	  fea00000-fea7ffff : 0000:00:02.0
	  fea80000-feafffff : 0000:00:02.1
	  feb00000-febfffff : 0000:00:02.0
	  fec00000-fec00fff : IOAPIC 0
	  fed00000-fed003ff : HPET 0

ie the one reserved region now ends up surrounding all the PCI resources
that were allocated inside of it by firmware, and because it is not
marked BUSY, drivers have no problem attaching to the pre-allocated
resources.
Reported-and-tested-by: NJonathan Corbet <corbet@lwn.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>