Don't warn in read_apic_id() when preemptible but only one CPU online.
Signed-off-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Yinghai Lu pointed out a bug in the previous patches,
fix double-shift of apicid.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
UV supports really big systems. So big, in fact, that the APICID register
does not contain enough bits to contain an APICID that is unique across all
cpus.
The UV BIOS supports 3 APICID modes:
- legacy mode. This mode uses the old APIC mode where
APICID is in bits [31:24] of the APICID register.
- x2apic mode. This mode is whitebox-compatible. APICIDs
are unique across all cpus. Standard x2apic APIC operations
(Intel-defined) can be used for IPIs. The node identifier
fits within the Intel-defined portion of the APICID register.
- x2apic-uv mode. In this mode, the APICIDs on each node have
unique IDs, but IDs on different node are not unique. For example,
if each mode has 32 cpus, the APICIDs on each node might be
0 - 31. Every node has the same set of IDs.
The UV hub is used to route IPIs/interrupts to the correct node.
Traditional APIC operations WILL NOT WORK.
In x2apic-uv mode, the ACPI tables all contain a full unique ID (note:
exact bit layout still changing but the following is close):
nnnnnnnnnnlc0cch
n = unique node number
l = socket number on board
c = core
h = hyperthread
Only the "lc0cch" bits are written to the APICID register. The remaining bits are
supplied by having the get_apic_id() function "OR" the extra bits into the value
read from the APICID register. (Hmmm.. why not keep the ENTIRE APICID register
in per-cpu data....)
The x2apic-uv mode is recognized by the MADT table containing:
oem_id = "SGI"
oem_table_id = "UV-X"
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add functions that can be used to determine if an x86_64
system is a SGI "UV" system. UV systems come in 3 types and
are identified by the OEM ID in the MADT.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Clean up references to x86_cpu_to_apicid. Removes extraneous
comments and standardizes on "x86_*_early_ptr" for the early
kernel init references.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Change the size of APICIDs from u8 to u16. This partially
supports the new x2apic mode that will be present on future
processor chips. (Chips actually support 32-bit APICIDs, but that
change is more intrusive. Supporting 16-bit is sufficient for now).
Signed-off-by: Jack Steiner <steiner@sgi.com>
I've included just the partial change from u8 to u16 apicids. The
remaining x2apic changes will be in a separate patch.
In addition, the fake_node_to_pxm_map[] and fake_apicid_to_node[]
tables have been moved from local data to the __initdata section
reducing stack pressure when MAX_NUMNODES and MAX_LOCAL_APIC are
increased in size.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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: Mike 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas 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: Mike Travis <travis@sgi.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
