Stash the first platform string matched by identify_cpu() in
powerpc_base_platform, and supply that to the ELF loader for the value
of AT_BASE_PLATFORM.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
nohz: adjust tick_nohz_stop_sched_tick() call of s390 as well
nohz: prevent tick stop outside of the idle loop
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:
u64 val = PAGE_ALIGN(size);
always returns a value < 4GB even if size is greater than 4GB.
The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):
#define PAGE_SHIFT 12
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.
Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.
See also lkml discussion: http://lkml.org/lkml/2008/6/11/237
[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of using the variable mmu_huge_psize to keep track of the huge
page size we use an array of MMU_PAGE_* values. For each supported huge
page size we need to know the hugepte_shift value and have a
pgtable_cache. The hstate or an mmu_huge_psizes index is passed to
functions so that they know which huge page size they should use.
The hugepage sizes 16M and 64K are setup(if available on the hardware) so
that they don't have to be set on the boot cmd line in order to use them.
The number of 16G pages have to be specified at boot-time though (e.g.
hugepagesz=16G hugepages=5).
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The huge page size is defined for 16G pages. If a hugepagesz of 16G is
specified at boot-time then it becomes the huge page size instead of the
default 16M.
The change in pgtable-64K.h is to the macro pte_iterate_hashed_subpages to
make the increment to va (the 1 being shifted) be a long so that it is not
shifted to 0. Otherwise it would create an infinite loop when the shift
value is for a 16G page (when base page size is 64K).
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 16G huge pages have to be reserved in the HMC prior to boot. The
location of the pages are placed in the device tree. This patch adds code
to scan the device tree during very early boot and save these page
locations until hugetlbfs is ready for them.
Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 16G page locations have been saved during early boot in an array. The
alloc_bootmem_huge_page() function adds a page from here to the
huge_boot_pages list.
Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Straight forward extensions for huge pages located in the PUD instead of
PMDs.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The goal of this patchset is to support multiple hugetlb page sizes. This
is achieved by introducing a new struct hstate structure, which
encapsulates the important hugetlb state and constants (eg. huge page
size, number of huge pages currently allocated, etc).
The hstate structure is then passed around the code which requires these
fields, they will do the right thing regardless of the exact hstate they
are operating on.
This patch adds the hstate structure, with a single global instance of it
(default_hstate), and does the basic work of converting hugetlb to use the
hstate.
Future patches will add more hstate structures to allow for different
hugetlbfs mounts to have different page sizes.
[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The double indirection here is not needed anywhere and hence (at least)
confusing.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This uses the new vm_ops->access to allow gdb to access the SPU local
store. We currently prevent access to problem state registers, this can
be done later if really needed but it's safer not to.
[akpm@linux-foundation.org: fix typo]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds ioremap_prot and pte_pgprot() so that one can extract protection
bits from a PTE and use them to ioremap_prot() (in order to support ptrace
of VM_IO | VM_PFNMAP as per Rik's patch).
This moves a couple of flag checks around in the ioremap implementations
of arch/powerpc. There's a side effect of allowing non-cacheable and
non-guarded mappings on ppc32 which before would always have _PAGE_GUARDED
set whenever _PAGE_NO_CACHE is.
(standard ioremap will still set _PAGE_GUARDED, but ioremap_prot will be
capable of setting such a non guarded mapping).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are a lot of places that define either a single bootmem descriptor or an
array of them. Use only one central array with MAX_NUMNODES items instead.
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Flag platforms as HAVE_CLK (or not) in Kconfig, based on whether they
support <linux/clk.h> calls, so that otherwise portable drivers which need
those calls can list that dependency.
Something like this is a prerequisite for merging the musb_hdrc driver,
currently used on platforms including Davinci, OMAP2430, OMAP3xx ... and
the discrete TUSB6010 chip, which doesn't have a natural platform
dependency. (Used with OMAP 2420 in current Nokia N8x0 tablets.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adjusts the placement of a reference context from
a spu affinity chain. The reference context can now be placed
only on nodes that have enough spus not intended to be used by
another gang (already running on the node).
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Currenlt,, it is possible to lock aff_mutex and
cbe_spu_info[n].list_mutex in different orders, allowing a deadlock to
occur. With this change, aff_mutex is not taken within a list_mutex
critical section anymore.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
This patch removes the old kgdb reminants from ARCH=powerpc and
implements the new style arch specific stub for the common kgdb core
interface.
It is possible to have xmon and kgdb in the same kernel, but you
cannot use both at the same time because there is only one set of
debug hooks.
The arch specific kgdb implementation saves the previous state of the
debug hooks and restores them if you unconfigure the kgdb I/O driver.
Kgdb should have no impact on a kernel that has no kgdb I/O driver
configured.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
kcalloc is supposed to be called with the count as its first argument and
the element size as the second.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (49 commits)
powerpc: Fix build bug with binutils < 2.18 and GCC < 4.2
powerpc/eeh: Don't panic when EEH_MAX_FAILS is exceeded
fbdev: Teaches offb about palette on radeon r5xx/r6xx
powerpc/cell/edac: Log a syndrome code in case of correctable error
powerpc/cell: Add DMA_ATTR_WEAK_ORDERING dma attribute and use in Cell IOMMU code
powerpc: Indicate which oprofile counters to use while in compat mode
powerpc/boot: Change spaces to tabs
powerpc: Remove duplicate 6xx option in Kconfig
powerpc: Use PPC_LONG and PPC_LONG_ALIGN in lib/string.S
powerpc: Use PPC_LONG_ALIGN in uaccess.h
powerpc: Add a #define for aligning to a long-sized boundary
powerpc: Fix OF parsing of 64 bits PCI addresses
powerpc: Use WARN_ON(1) instead of __WARN()
powerpc: Fix support for latencytop
powerpc/ps3: Update ps3_defconfig
powerpc/ps3: Add a sub-match id to ps3_system_bus
powerpc: Add a 6xx defconfig
powerpc/dma: Use the struct dma_attrs in iommu code
powerpc/cell: Add support for power button of future IBM cell blades
powerpc/cell: Cleanup sysreset_hack for IBM cell blades
...
This allow to dynamically generate attributes and share show/store
functions between attributes. Right now most attributes are generated
by special macros and lots of duplicated code. With the attribute
passed it's instead possible to attach some data to the attribute
and then use that in shared low level functions to do different things.
I need this for the dynamically generated bank attributes in the x86
machine check code, but it'll allow some further cleanups.
I converted all users in tree to the new show/store prototype. It's a single
huge patch to avoid unbisectable sections.
Runtime tested: x86-32, x86-64
Compiled only: ia64, powerpc
Not compile tested/only grep converted: sh, arm, avr32
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We have the dev_printk() variants for this kind of thing, use them
instead of directly trying to access the bus_id field of struct device.
This is done in order to remove bus_id entirely.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
binutils < 2.18 has a bug that makes it misbehave when taking an
ELF file with all segments at load address 0 as input. This
happens when running "strip" on vmlinux, because of the AT() magic
in this linker script. People using GCC >= 4.2 won't run into
this problem, because the "build-id" support will put some data
into the "notes" segment (at a non-zero load address).
To work around this, we force some data into both the "dummy"
segment and the kernel segment, so the dummy segment will get a
non-zero load address. It's not enough to always create the
"notes" segment, since if nothing gets assigned to it, its load
address will be zero.
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Tested-By: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch changes the EEH_MAX_FAILS action from panic to printing an
error message. Panicking under under this condition is too harsh.
Although performance will be affected and the device may not recover,
the system is still running, which at the very least should allow for a
more graceful shutdown. The patch also removes the msleep() within a
spinlock, which can lead to a deadlock and is not recommended.
Signed-off-by: Mike Mason <mmlnx@us.ibm.com>
Acked-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Introduce a new dma attriblue DMA_ATTR_WEAK_ORDERING to use weak ordering
on DMA mappings in the Cell processor. Add the code to the Cell's IOMMU
implementation to use this code.
Dynamic mappings can be weakly or strongly ordered on an individual basis
but the fixed mapping has to be either completely strong or completely weak.
This is currently decided by a kernel boot option (pass iommu_fixed=weak
for a weakly ordered fixed linear mapping, strongly ordered is the default).
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
While running on a system with new hardware and a kernel where the
cpu_specs[] table does not recognize the new hardware, the identify_cpu()
routine will select the default case as it searches through cpu_specs[]
in an attempt to match the real PVR. Once the default case is selected,
non of the oprofile counters and/or fields have been set up or defined.
When identify_cpu() is called once more with the logical PVR, some of
the cpu specific fields are replaced with the exception of the oprofile
related ones. However, in the case where we have actually taken the
default case while searching for the real PVR, we need to tell
oprofile that we are now running in compatibility mode so it can pick up
the correct counters. We do this by setting the oprofile_cpu_type field
to be that taken from the cpu_specs[] for the cpu we are now emulating.
This change will detect that we are now altering the real PVR and determine
if we also need to update the oprofile_cpu_type field.
Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
For C code spaces versus tabs is just a religious issue,
but for Makefiles it actually matters.
This patch fixes he following errors:
/home/bunk/linux/kernel-2.6/git/linux-2.6/arch/powerpc/boot/Makefile:166: *** missing separator. Stop.
/home/bunk/linux/kernel-2.6/git/linux-2.6/arch/powerpc/boot/Makefile:171: *** missing separator. Stop.
Since this was inside an ifdef DTC_GENPARSER it was not a problem unless
someone wanted to regenerate the shipped generated files.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The real option is above in the same Kconfig file.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Replace ifdef clutter with the PPC_LONG and PPC_LONG_ALIGN macros
for readability.
No change to the generated code.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The OF parsing code for PCI addresses isn't always treating properly
the address space indication 0b11 (ie. 0x3) as meaning 64 bits
memory space.
This means that it fails to parse addresses for PCI BARs that have
this encoding set by the firmware, which happens on some SLOF
versions and breaks offb palette handling on Powerstation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
__WARN() is not defined for all configs, use WARN_ON(1) instead.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to pass the kernel stack pointer instead of the user space
stack pointer in save_stack_trace_tsk().
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Add sub match id for ps3 system bus so that two different system bus
devices can be connected to a shared device.
Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is a defconfig from Dave Jones and should be similar (if not
identical) to the fedora ppc32 defconfig. The intent is to cover all
cache coherent 6xx based chips and platforms as reasonable.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Update iommu_alloc() to take the struct dma_attrs and pass them on to
tce_build(). This change propagates down to the tce_build functions of
all the platforms.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds support for the power button on future IBM cell blades.
It actually doesn't shut down the machine. Instead it exposes an
input device /dev/input/event0 to userspace which sends KEY_POWER
if power button has been pressed.
haldaemon actually recognizes the button, so a plattform independent acpid
replacement should handle it correctly.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds a config option for the sysreset_hack used for
IBM Cell blades. The code is moves from pervasive.c into ras.c and
gets it's own init method.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds a cpufreq governor that takes the number of running spus
into account. It's very similar to the ondemand governor, but not as complex.
Instead of hacking spu load into the ondemand governor it might be easier to
have cpufreq accepting multiple governors per cpu in future.
Don't know if this is the right way, but it would keep the governors simple.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
DDR2 memory DIMMs on the Axon could be accessed only as one partition
when using file system drivers which are using the direct_access() method.
This patch enables for such file system drivers to access Axon's DDR2 memory
even if it is splitted in several partitions.
Signed-off-by: Maxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Axonram module registers one block device for each DDR2 DIMM found
on a system. This means that each DDR2 DIMM becomes its own block device
major number. This patch lets axonram module to register the only one
block device for all DDR2 DIMMs which also spares kernel resources.
Signed-off-by: Maxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Flush the shadow mmu before removing regions to avoid stale entries.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch enables coalesced MMIO for powerpc architecture.
It defines KVM_MMIO_PAGE_OFFSET and KVM_CAP_COALESCED_MMIO.
It enables the compilation of coalesced_mmio.c.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:
scheduler switch to idle task
enable interrupts
Window starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick
----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.
The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.
Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.
cpu_idle()
{
preempt_disable();
while(1) {
tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
are in the idle loop
while (!need_resched())
halt();
tick_nohz_restart_sched_tick(); <- disables NOHZ mode
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
In hindsight we should have done this forever, but ...
/me grabs a large brown paperbag.
Debugged-by: Jack Ren <jack.ren@marvell.com>,
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
