Introduce a function to read the local APIC_ID.

This change is in preparation for additional changes to
the APICID functions that will come in a later patch.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch converts the x86_cpu_to_apicid array to be a per cpu
variable. This saves sizeof(apicid) * NR unused cpus.  Access is mostly
from startup and CPU HOTPLUG functions.

MP_processor_info() is one of the functions that require access to the
x86_cpu_to_apicid array before the per_cpu data area is setup.  For this
case, a pointer to the __initdata array is initialized in setup_arch()
and removed in smp_prepare_cpus() after the per_cpu data area is
initialized.

A second change is included to change the initial array value of ARCH
i386 from 0xff to BAD_APICID to be consistent with ARCH x86_64.
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Remove the x86_cpu_to_log_apicid array.  It is set in
arch/x86_64/kernel/genapic_flat.c:flat_init_apic_ldr() and
arch/x86_64/kernel/smpboot.c:do_boot_cpu() but it is never
referenced.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix:

In file included from include2/asm/apic.h:5,
                 from include2/asm/smp.h:15,
                 from linux/arch/x86_64/kernel/genapic_flat.c:18:
linux/include/linux/pm.h: In function ‘call_platform_enable_wakeup’:
linux/include/linux/pm.h:331: error: ‘EIO’ undeclared (first use in this function)
linux/include/linux/pm.h:331: error: (Each undeclared identifier is reported only once
linux/include/linux/pm.h:331: error: for each function it appears in.)
Signed-off-by: NAndi Kleen <ak@suse.de>

Implement __send_IPI_dest_field which can be used to send IPIs when the
"destination shorthand" field of the ICR is set to 00 (destination
field). Use it whenever possible.
Signed-off-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>

Move inclusion of asm/fixmap.h to where it is really used rather than
where it may have been used long ago (requires a few other adjustments
to includes due to previous implicit dependencies).
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

TARGET_CPUS is the default irq routing poicy.  It specifies which cpus the
kernel should aim an irq at.  In physflat delivery mode we can route an irq to
a single cpu.  But that doesn't mean our default policy should only be a
single cpu is allowed.

By allowing the irq routing code to select from multiple cpus this enables
systems with more irqs then we can service on a single processor to actually
work.

I just audited and tested the code and irqbalance doesn't care, and the
io_apic.c doesn't care if we have extra cpus in the mask.  Everything will use
or assume we are using the lowest numbered cpu in the mask if we can't use
them all.

So this should result in no behavior changes except on systems that need it.

Thanks for YH Lu for spotting this problem in his testing.

Cc: Yinghai Lu <yinghai.lu@amd.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

The problem we can't take advantage of lowest priority delivery mode if
the vectors are allocated for only one cpu at a time.  Nor can we work
around hardware that assumes lowest priority delivery mode is always
used with several cpus.

So this patch introduces the concept of a vector_allocation_domain.  A
set of cpus that will receive an irq on the same vector.  Currently the
code for implementing this is placed in the genapic structure so we can
vary this depending on how we are using the io_apics.

This allows us to restore the previous behaviour of genapic_flat without
removing the benefits of having separate vector allocation for large
machines.

This should also fix the problem report where a hyperthreaded cpu was
receving the irq on the wrong hyperthread when in logical delivery mode
because the previous behaviour is restored.

This patch properly records our allocation of the first 16 irqs to the
first 16 available vectors on all cpus.  This should be fine but it may
run into problems with multiple interrupts at the same interrupt level.
Except for some badly maintained comments in the code and the behaviour
of the interrupt allocator I have no real understanding of that problem.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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>

The genapic field and the accessor macro weren't used anywhere.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

On some i386/x86_64 systems, sending an NMI IPI as a broadcast will
reset the system.  This seems to be a BIOS bug which affects machines
where one or more cpus are not under OS control.  It occurs on HT
systems with a version of the OS that is not compiled without HT
support.  It also occurs when a system is booted with max_cpus=n where
2 <= n < cpus known to the BIOS.  The fix is to always send NMI IPI as
a mask instead of as a broadcast.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

vSMPowered systems use apic_cluster too.  Forcing apic_physflat works
on these systems too, but only if we change phys_pkg_id to use
hard_smp_prcoessor_id() instead of cpuid_ebx.  I am guessing other
multichassi cluster systems would need this too.
Signed-off-by: Nravikiran thirumalai <kiran@scalex86.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;

...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...

But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.
Signed-off-by: NZwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

No x86-64 chipset has this bug

Generated code doesn't change because it was always disabled.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The use of non-shortcut version of routines breaking CPU hotplug.  The option
to select this via cmdline also is deleted with the physflat patch, hence
directly placing this code under CONFIG_HOTPLUG_CPU.

We dont want to use broadcast mode IPI's when hotplug is enabled.  This causes
bad effects in send IPI to a cpu that is offline which can trip when the cpu
is in the process of being kicked alive.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NAndi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use physical mode instead of logical mode to address more CPUs.  This is also
used in the CPU hotplug case to avoid a race.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Will be obsolete with physflat.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch provides an option to switch broadcast or use mask version for
sending IPI's.  If CONFIG_HOTPLUG_CPU is defined, we choose not to use
broadcast shortcuts by default, otherwise we choose broadcast mode as default.

both cases, one can change this via startup cmd line option, to choose
no-broadcast mode.

	no_ipi_broadcast=1

This is provided on request from Andi Kleen, since he doesnt agree with
replacing IPI shortcuts as a solution for CPU hotplug.  Without removing
broadcast IPI's, it would mean lots of new code for __cpu_up() path, which
would acheive the same results.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NAndi Kleen <ak@muc.de>
Acked-by: NZwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Broadcast IPI's provide un-expected behaviour for cpu hotplug.  CPU's in
offline state also end up receiving the IPI.  Once the cpus become online they
receive these stale IPI's which are bad and introduce unexpected behaviour.

This is easily avoided by not sending a broadcast and addressing just the
CPU's in online map.  Doing prelim cycle counts it appears there is no big
overhead and numbers seem around 0x3000-0x3900 on an average on x86 and x86_64
systems with CPUS running 3G, both for broadcast and mask version of the
API's.

The shortcuts are useful only for flat mode (where the perf shows no
degradation), and in cluster mode, its unicast anyway.  Its simpler to just
not use broadcast anymore.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NAndi Kleen <ak@muc.de>
Acked-by: NZwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!