linux-stable.git/arch/powerpc, branch v3.2.62

locking/mutex: Disable optimistic spinning on some architectures

2014-08-06T17:07:38+00:00

commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream.

The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.

There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.

Opt in for known good archs.

Signed-off-by: Peter Zijlstra 
Reported-by: Mikulas Patocka 
Cc: David Miller 
Cc: Chris Metcalf 
Cc: James Bottomley 
Cc: Vineet Gupta 
Cc: Jason Low 
Cc: Waiman Long 
Cc: "James E.J. Bottomley" 
Cc: Paul McKenney 
Cc: John David Anglin 
Cc: James Hogan 
Cc: Linus Torvalds 
Cc: Davidlohr Bueso 
Cc: Benjamin Herrenschmidt 
Cc: Catalin Marinas 
Cc: Russell King 
Cc: Will Deacon 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.2:
 - Adjust context
 - Drop arm64 change]
Signed-off-by: Ben Hutchings

powerpc: Don't setup CPUs with bad status

2014-07-11T12:33:49+00:00

commit 59a53afe70fd530040bdc69581f03d880157f15a upstream.

OPAL will mark a CPU that is guarded as "bad" in the status property of the CPU
node.

Unfortunatley Linux doesn't check this property and will put the bad CPU in the
present map.  This has caused hangs on booting when we try to unsplit the core.

This patch checks the CPU is avaliable via this status property before putting
it in the present map.

Signed-off-by: Michael Neuling 
Tested-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

powerpc/serial: Use saner flags when creating legacy ports

2014-07-11T12:33:46+00:00

commit c4cad90f9e9dcb85afc5e75a02ae3522ed077296 upstream.

We had a mix & match of flags used when creating legacy ports
depending on where we found them in the device-tree. Among others
we were missing UPF_SKIP_TEST for some kind of ISA ports which is
a problem as quite a few UARTs out there don't support the loopback
test (such as a lot of BMCs).

Let's pick the set of flags used by the SoC code and generalize it
which means autoconf, no loopback test, irq maybe shared and fixed
port.

Sending to stable as the lack of UPF_SKIP_TEST is breaking
serial on some machines so I want this back into distros

Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

powerpc: Fix 64 bit builds with binutils 2.24

2014-07-11T12:33:42+00:00

commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck 
Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

powerpc: Add vr save/restore functions

2014-06-09T12:28:54+00:00

commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

powerpc: Align p_dyn, p_rela and p_st symbols

2014-04-01T23:58:58+00:00

commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard 
Tested-by: Laurent Dufour 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

powerpc/crashdump : Fix page frame number check in copy_oldmem_page

2014-04-01T23:58:57+00:00

commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour 
Tested-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

powerpc: Make sure "cache" directory is removed when offlining cpu

2014-04-01T23:58:45+00:00

commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

KVM: PPC: e500: Fix bad address type in deliver_tlb_misss()

2014-04-01T23:58:45+00:00

commit 70713fe315ed14cd1bb07d1a7f33e973d136ae3d upstream.

Use gva_t instead of unsigned int for eaddr in deliver_tlb_miss().

Signed-off-by: Mihai Caraman 
Signed-off-by: Alexander Graf 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings

powerpc: Fix bad stack check in exception entry

2014-02-15T19:20:16+00:00

commit 90ff5d688e61f49f23545ffab6228bd7e87e6dc7 upstream.

In EXCEPTION_PROLOG_COMMON() we check to see if the stack pointer (r1)
is valid when coming from the kernel.  If it's not valid, we die but
with a nice oops message.

Currently we allocate a stack frame (subtract INT_FRAME_SIZE) before we
check to see if the stack pointer is negative.  Unfortunately, this
won't detect a bad stack where r1 is less than INT_FRAME_SIZE.

This patch fixes the check to compare the modified r1 with
-INT_FRAME_SIZE.  With this, bad kernel stack pointers (including NULL
pointers) are correctly detected again.

Kudos to Paulus for finding this.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings