Commit Graph

276060 Commits

Author SHA1 Message Date
Benjamin Herrenschmidt
11eab297f5 powerpc: Add support for OpenBlockS 600
So I've had one of these for a while and it looks like the vendor never
bothered submitting the support upstream.

This adds it using ppc40x_simple and provides a device-tree.

There are some changes to the boot wrapper because the way u-boot works
on this thing, it seems to expect a multipart image with the kernel,
initrd and dtb in it.

The USB support is missing as it needs the yet unmerged driver for
the DWC OTG part and the GPIOs may need further definition in the dts.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-08 14:22:52 +11:00
Benjamin Herrenschmidt
faa8bf8878 Merge branch 'booke-hugetlb' into next 2011-12-08 13:20:34 +11:00
Benjamin Herrenschmidt
48b1bf86c3 Merge branch 'mpic' into next 2011-12-07 18:22:47 +11:00
Benjamin Herrenschmidt
4666ca2aa3 powerpc/pci: Make pci_read_irq_line() static
It's only used inside the same file where it's defined. There's
also no point exporting it anymore.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 18:04:58 +11:00
Benjamin Herrenschmidt
40dfef66a9 powerpc/powernv: Workaround OFW issues in prom_init.c
Open Firmware on OPAL machines seems to have issues if we close
stdin and/or we try to print things after calling "quiesce" so
we avoid doing both.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 18:04:53 +11:00
Benjamin Herrenschmidt
cee72d5bb4 powerpc/powernv: Display diag data on p7ioc EEH errors
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 18:04:02 +11:00
Benjamin Herrenschmidt
f11fe5524a powerpc/powernv: Update OPAL interfaces
This adds some more interfaces for OPAL v2

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 18:02:02 +11:00
Becky Bruce
1f6820b4c1 powerpc: Define/use HUGETLB_NEED_PRELOAD insead of complicated #if
Define HUGETLB_NEED_PRELOAD in mmu-book3e.h for CONFIG_PPC64 instead
of having a much more complicated #if block.  This is easier to read
and maintain.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:24 +11:00
Becky Bruce
d93e4d7d72 powerpc/book3e: Change hugetlb preload to take vma argument
This avoids an extra find_vma() and is less error-prone.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:24 +11:00
Becky Bruce
1257a76547 powerpc: Enable hugetlb by default for corenet64 platforms
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:23 +11:00
Becky Bruce
41caebd123 powerpc: Enable Hugetlb by default for 32-bit 85xx/corenet
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:23 +11:00
Becky Bruce
a475c8ecc6 powerpc: Kconfig updates for FSL BookE HUGETLB 64-bit
Allow hugetlb to be enabled on 64b FSL_BOOK3E.  No platforms enable
it by default yet.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:23 +11:00
Becky Bruce
a6146888be powerpc: Add gpages reservation code for 64-bit FSL BOOKE
For 64-bit FSL_BOOKE implementations, gigantic pages need to be
reserved at boot time by the memblock code based on the command line.
This adds the call that handles the reservation, and fixes some code
comments.

It also removes the previous pr_err when reserve_hugetlb_gpages
is called on a system without hugetlb enabled - the way the code is
structured, the call is unconditional and the resulting error message
spurious and confusing.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:23 +11:00
Becky Bruce
d1b9b12811 powerpc: Add hugepage support to 64-bit tablewalk code for FSL_BOOK3E
Before hugetlb, at each level of the table, we test for
!0 to determine if we have a valid table entry.  With hugetlb, this
compare becomes:
        < 0 is a normal entry
        0 is an invalid entry
        > 0 is huge

This works because the hugepage code pulls the top bit off the entry
(which for non-huge entries always has the top bit set) as an
indicator that we have a hugepage.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:22 +11:00
Becky Bruce
27609a42ee powerpc: Whitespace/comment changes to tlb_low_64e.S
I happened to comment this code while I was digging through it;
we might as well commit that.  I also made some whitespace
changes - the existing code had a lot of unnecessary newlines
that I found annoying when I was working on my tiny laptop.

No functional changes.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:22 +11:00
Becky Bruce
881fde1db5 powerpc: hugetlb: modify include usage for FSL BookE code
The original 32-bit hugetlb implementation used PPC64 vs PPC32 to
determine which code path to take.  However, the final hugetlb
implementation for 64-bit FSL ended up shared with the FSL
32-bit code so the actual check needs to be FSL_BOOK3E vs
everything else.  This patch changes the include protections to
reflect this.

There are also a couple of related comment fixes.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:22 +11:00
Becky Bruce
a1cd541988 powerpc: Update hugetlb huge_pte_alloc and tablewalk code for FSL BOOKE
This updates the hugetlb page table code to handle 64-bit FSL_BOOKE.
The previous 32-bit work counted on the inner levels of the page table
collapsing.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:22 +11:00
Becky Bruce
8c1674de2b powerpc: Fix booke hugetlb preload code for PPC_MM_SLICES and 64-bit
This patch does 2 things: It corrects the code that determines the
size to write into MAS1 for the PPC_MM_SLICES case (this originally
came from David Gibson and I had incorrectly altered it), and it
changes the methodolody used to calculate the size for !PPC_MM_SLICES
to work for 64-bit as well as 32-bit.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:21 +11:00
Becky Bruce
97632e6fbe powerpc: hugetlb: fix huge_ptep_set_access_flags return value
There was an unconditional return of "1" in the original code
from David Gibson, and I dropped it because it wasn't needed
for FSL BOOKE 32-bit.  However, not all systems (including 64-bit
FSL BOOKE) do loading of the hpte from the fault handler asm
and depend on this function returning 1, which causes a call
to update_mmu_cache() that writes an entry into the tlb.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:21 +11:00
Becky Bruce
7651295944 powerpc: Only define HAVE_ARCH_HUGETLB_UNMAPPED_AREA if PPC_MM_SLICES
If we don't have slices, we should be able to use the generic
hugetlb_get_unmapped_area() code

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 16:26:21 +11:00
Kyle Moffett
09dc34a95b powerpc/mpic: Add in-core support for cascaded MPICs
The Cell and PowerMac platforms use virtually identical cascaded-IRQ
setup code, so just merge it into the core.  Ideally this code would
trigger automatically when an MPIC device-node specifies an "interrupts"
property, perhaps even enabling MPIC_SECONDARY along the way.

Unfortunately, Benjamin Herrenschmidt has had bad experiences in the
past with the quality of Apple PowerMac device-trees, so to be safe we
will only try to parse out an IRQ if the MPIC_SECONDARY flag is set by
the caller.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:09 +11:00
Kyle Moffett
c51242e708 powerpc/mpic: Cache the device-tree node in "struct mpic"
Store the node pointer in the MPIC during initialization so that all of
the later operational code can just reuse the cached pointer.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:08 +11:00
Kyle Moffett
c579bc766a powerpc/mpic: Put "pic-no-reset" test back into the MPIC code
There's not really any reason to have this one-liner in a separate
static inline function, given that all the other similar tests are
already in the alloc_mpic() code.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:08 +11:00
Kyle Moffett
e62b760179 powerpc/mpic: Don't open-code dcr_resource_start
Don't open-code the OpenFirmware "dcr-reg" property lookup trying to map
DCR resources.  This makes the code a bit easier to read.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:08 +11:00
Kyle Moffett
be8bec56df powerpc/mpic: Invert the meaning of MPIC_PRIMARY
It turns out that there are only 2 in-tree platforms which use MPICs
which are not "primary":  IBM Cell and PowerMac.  To reduce the
complexity of the typical board setup code, invert the MPIC_PRIMARY bit
into MPIC_SECONDARY.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:08 +11:00
Kyle Moffett
996983b75c powerpc/mpic: Search for open-pic device-tree node if NULL
Almost all PowerPC platforms use a standard "open-pic" device node so
the mpic_alloc() function now accepts NULL for the device-node.  This
will cause it to perform a default search with of_find_matching_node().

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:07 +11:00
Kyle Moffett
e7a98675ca powerpc/mpic: Save computed phys_addr for board-specific code
The MPIC code can already perform an automatic OF address translation
step as part of mpic_alloc(), but several boards need to use that base
address when they perform mpic_assign_isu().

The easiest solution is to save the computed physical address into the
"struct mpic" for later use by the board code.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:07 +11:00
Kyle Moffett
5bdb6f2e58 powerpc/mpic: Assume a device-node was passed in mpic_alloc()
All of the existing callers of mpic_alloc() pass in a non-NULL
device-node pointer, so the checks for a NULL device-node may be
removed.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:07 +11:00
Kyle Moffett
8bf4156896 powerpc: Consolidate mpic_alloc() OF address translation
Instead of using the open-coded "reg" property lookup and address
translation in mpic_alloc(), directly call of_address_to_resource().
This includes various workarounds for special cases which the naive
of_address_translate() does not.

Afterwards it is possible to remove the copiously copy-pasted calls to
of_address_translate() from the 85xx/86xx/powermac platforms.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:06 +11:00
Kyle Moffett
582d3e0994 powerpc/85xx: Move mpc85xx_smp_init() decl to a new "smp.h"
This removes a bunch of "extern" declarations and CONFIG_SMP ifdefs.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-07 13:43:06 +11:00
Dan McGee
fa8cbaaf5a powerpc+sparc64/mm: Remove hack in mmap randomize layout
Since commit 8a0a9bd4db, this comment in mmap_rnd() does not
hold true as the value returned by get_random_int() will in fact be

different every single call. Remove the comment and simplify the code
back to its original desired form.

This reverts commit a5adc91a4b which is no longer necessary and
also fixes the sparc code that copied this same adjustment.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:09 +11:00
Anton Blanchard
3ce21cdfe9 powerpc/xics: Harden xics hypervisor backend
During kdump stress testing I sometimes see the kdump kernel panic
with:

  Interrupt 0x306 (real) is invalid, disabling it.
  Kernel panic - not syncing: bad return code EOI - rc = -4, value=ff000306

Instead of panicing print the error message, dump the stack the first
time it happens and continue on. Add some more information to the
debug messages as well.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:09 +11:00
Anton Blanchard
3bfd0c9c8f powerpc: Decode correct MSR bits in oops output
On a 64bit book3s machine I have an oops from a system reset that
claims the book3e CE bit was set:

MSR: 8000000000021032 <ME,CE,IR,DR>  CR: 24004082  XER: 00000010

On a book3s machine system reset sets IBM bit 46 and 47 depending on
the power saving mode. Separate the definitions by type and for
completeness add the rest of the bits in.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:09 +11:00
Matthew McClintock
e1fc235d74 arch/powerpc: Remove duplicate/redundant Altivec entries
In lieu of having multiple similiar lines, we can just have one
generic cpu-as line for CONFIG_ALTIVEC

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:09 +11:00
Dmitry Eremin-Solenikov
f49a0c9c64 powerpc/maple: Enable access to HT Host-Bridge on Maple
CPC925/CPC945 use special window to access host bridge functionality of
u3-ht. Provide a way to access this device.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:08 +11:00
sukadev@linux.vnet.ibm.com
1d54cf2b97 powerpc: Implement CONFIG_STRICT_DEVMEM
As described in the help text in the patch, this token restricts general
access to /dev/mem as a way of increasing the security. Specifically, access
to exclusive IOMEM and kernel RAM is denied unless CONFIG_STRICT_DEVMEM is
set to 'n'.

Implement the 'devmem_is_allowed()' interface for Powerpc. It will be
called from range_is_allowed() when userpsace attempts to access /dev/mem.

This patch is based on an earlier patch from Steve Best and with input from
Paul Mackerras and Scott Wood.

[BenH] Fixed a typo or two and removed the generic change which should
       be submitted as a separate patch

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-28 11:42:08 +11:00
Benjamin Herrenschmidt
56368797d6 Merge remote-tracking branch 'kumar/next' into next 2011-11-25 15:25:39 +11:00
Justin P. Mattock
e075cd7001 powerpc/mpic: Remove extra semicolon.
The patch below removes an extra semicolon.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
CC: linuxppc-dev@lists.ozlabs.org
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:53:25 +11:00
Ananth N Mavinakayanahalli
595fe91447 powerpc: Export PIR data through sysfs
On Fri, Nov 11, 2011 at 10:17:55AM +0530, Ananth N Mavinakayanahalli wrote:
> >
> > At this rate we're going to end up with no bits left for CPU features
> > way too quickly... Especially for something we only care about once at
> > boot time.
> >
> > Wouldn't CPU_FTR_PPCAS_ARCH_V2 be a good enough test ?
>
> /me checks Cell manuals... yes, that test would be good enough. I will
> cook up a patch to use this.

Here it is...

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:53:23 +11:00
Benjamin Herrenschmidt
184cd4a3b9 powerpc/powernv: PCI support for p7IOC under OPAL v2
This adds support for p7IOC (and possibly other IODA v1 IO Hubs)
using OPAL v2 interfaces.

We completely take over resource assignment and assign them using an
algorithm that hands out device BARs in a way that makes them fit in
individual segments of the M32 window of the bridge, which enables us
to assign individual PEs to devices and functions.

The current implementation gives out a PE per functions on PCIe, and a
PE for the entire bridge for PCIe to PCI-X bridges.

This can be adjusted / fine tuned later.

We also setup DMA resources (32-bit only for now) and MSIs (both 32-bit
and 64-bit MSI are supported).

The DMA allocation tries to divide the available 256M segments of the
32-bit DMA address space "fairly" among PEs. This is done using a
"weight" heuristic which assigns less value to things like OHCI USB
controllers than, for example SCSI RAID controllers. This algorithm
will probably want some fine tuning for specific devices or device
types.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:53:15 +11:00
Benjamin Herrenschmidt
ca45cfe31e powerpc/powernv: Fixup p7ioc PCIe root complex class code
It advertises "host bridge" instead of "PCI to PCI bridge" which confuses
the Linux probe code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:32:59 +11:00
Benjamin Herrenschmidt
1f1616e864 powerpc/powernv: Add TCE SW invalidation support
This is used for newer IO Hubs such as p7IOC.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:32:57 +11:00
Benjamin Herrenschmidt
48c2ce97fa powerpc/pci: Change how re-assigning resouces work
When PCI_REASSIGN_ALL_RSRC is set, we used to clear all bus resources
at the beginning of survey and re-allocate them later.

This changes it so instead, during early fixup, we mark all resources
as IORESOURCE_UNSET and move them down to be 0-based.

Later, if bus resources are still unset at the beginning of the survey,
then we clear them.

This shouldn't impact the re-assignment case on 4xx, but will enable
us to have the platform do some custom resource assignment before the
survey, by clearing individual resources IORESOURCE_UNSET bit.

Also limits the clutter in the kernel log from fixup when re-assigning
since we don't care about the offset applied to the BAR values in this
case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:32:55 +11:00
Benjamin Herrenschmidt
491b98c315 powerpc/pci: Add a platform hook after probe and before resource survey
Some platforms need to perform resource allocation using a custom algorithm
due to HW constraints, or may want to tweak things globally below a host
bridge. For example OPAL support for IODA will need to perform a
resource allocation pass that applies IODA specific segmentation
constraints to MMIO which cannot be done simply using the kernel generic
resource management code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:32:53 +11:00
Geoff Thorpe
09c188c4f6 powerpc: Add pgprot_cached_noncoherent()
This adds a pgprot combination required by some cache-enabled IO device
mappings, such as Freescale datapath (QMan and BMan) portals.

Signed-off-by: Geoff Thorpe <geoff@geoffthorpe.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:32:52 +11:00
Thomas Gleixner
e8d2c47352 powerpc: Allow irq threading
All interrupts which must be non threaded are marked
IRQF_NO_THREAD. So it's safe to allow force threaded handlers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:14:38 +11:00
Thomas Gleixner
3b5e16d7ad powerpc: Mark IPI interrupts IRQF_NO_THREAD
IPI handlers cannot be threaded. Remove the obsolete IRQF_DISABLED
flag (see commit e58aa3d2) while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:14:38 +11:00
Thomas Gleixner
5f20b85dc2 powerpc/wsp: Mark opb cascade handler IRQF_NO_THREAD
Cascade handlers must run in hard interrupt context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:11:29 +11:00
Thomas Gleixner
c6c56bdda1 powerpc/85xx: Mark cascade irq IRQF_NO_THREAD
Cascade interrupt must run in hard interrupt context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:11:29 +11:00
Ravi K. Nittala
df17f56d8a powerpc/pseries: Cancel RTAS event scan before firmware flash
The RTAS firmware flash update is conducted using an RTAS call that is
serialized by lock_rtas() which uses spin_lock. While the flash is in
progress, rtasd performs scan for any RTAS events that are generated by
the system. rtasd keeps scanning for the RTAS events generated on the
machine. This is performed via workqueue mechanism. The rtas_event_scan()
also uses an RTAS call to scan the events, eventually trying to acquire
the spin_lock before issuing the request.

The flash update takes a while to complete and during this time, any other
RTAS call has to wait. In this case, rtas_event_scan() waits for a long time
on the spin_lock resulting in a soft lockup.

Fix: Just before the flash update is performed, the queued rtas_event_scan()
work item is cancelled from the work queue so that there is no other RTAS
call issued while the flash is in progress. After the flash completes, the
system reboots and the rtas_event_scan() is rescheduled.

Signed-off-by: Suzuki Poulose <suzuki@in.ibm.com>
Signed-off-by: Ravi Nittala <ravi.nittala@in.ibm.com>
Reported-by: Divya Vikas <divya.vikas@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 14:11:29 +11:00