This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.
This patch:
Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past. This is to avoid conflicts.
Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix following warning:
WARNING: arch/x86/kernel/built-in.o(.text+0x10ea0): Section mismatch: reference to .cpuinit.data:num_processors in 'acpi_unmap_lsapic'
The exported function acpi_unmap_lsapic() references
the variable num_processors that is annotated __cpuinitdata.
Remove the annotation of num_processors as we never know
when an exported function are called.
And drop the needless initialsation to 0.
Warning was seen on 64 bit but similar pattern were seen
in 32 bit - so fix it up there too.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
These are useful in figuring out early-mapping problems.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
commit c434b7a6ae
(x86: avoid wasting IRQs for PCI devices)
created a concept of "IRQ compression" on i386
to conserve IRQ numbers on systems with many
sparsely populated IO APICs.
The same scheme was also added to x86_64,
but later removed when x86_64 recieved an IRQ over-haul
that made it unnecessary -- including per-CPU
IRQ vectors that greatly increased the IRQ capacity
on the machine.
i386 has not received the analogous over-haul,
and thus a previous attempt to delete IRQ compression
from i386 was rejected on the theory that there may
exist machines that actually need it. The fact is
that the author of IRQ compression patch was unable
to confirm the actual existence of such a system.
As a result, all i386 kernels with IOAPIC support
pay the following:
1. confusion
IRQ compression re-names the traditional IOAPIC
pin numbers (aka ACPI GSI's) into sequential IRQ #s:
ACPI: PCI Interrupt 0000:00:1c.0[A] -> GSI 20 (level, low) -> IRQ 16
ACPI: PCI Interrupt 0000:00:1c.1[B] -> GSI 21 (level, low) -> IRQ 17
ACPI: PCI Interrupt 0000:00:1c.2[C] -> GSI 22 (level, low) -> IRQ 18
ACPI: PCI Interrupt 0000:00:1c.3[D] -> GSI 23 (level, low) -> IRQ 19
ACPI: PCI Interrupt 0000:00:1c.4[A] -> GSI 20 (level, low) -> IRQ 16
This makes /proc/interrupts look different
depending on system configuration and device probe order.
It is also different than the x86_64 kernel running
on the exact same system. As a result, programmers
get confused when comparing systems.
2. complexity
The IRQ code in Linux is already overly complex,
and IRQ compression makes it worse. There have
already been two bug workarounds related to IRQ
compression -- the IRQ0 timer workaround and
the VIA PCI IRQ workaround.
3. size
All i386 kernels with IOAPIC support contain an int[4096] --
a 4 page array to contain the renamed IRQs.
So while the irq compression code on i386 should really
be deleted -- even before merging the x86_64 irq-overhaul,
this patch simply disables it on all high volume systems
to avoid problems #1 and #2 on most all i386 systems.
A large system with pin numbers >=64 will still have compression
to conserve limited IRQ numbers for sparse IOAPICS. However,
the vast majority of the planet, those with only pin numbers < 64
will use an identity GSI -> IRQ mapping.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Bring the mpspec variants into sync to prepare merging and
paravirt support.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
