linux-toradex.git/arch/xtensa/configs, branch v4.4.26

Merge tag 'xtensa-20151108' of git://github.com/czankel/xtensa-linux

2015-11-10T00:32:13+00:00

Pull xtensa updates from Chris Zankel:

 - fix remaining issues with noMMU cores
 - fix build for cores w/o cache or zero overhead loop options
 - fix boot of secondary cores in SMP configuration
 - add support for DMA to high memory pages
 - add dma_to_phys and phys_to_dma functions.

* tag 'xtensa-20151108' of git://github.com/czankel/xtensa-linux:
  xtensa: implement dma_to_phys and phys_to_dma
  xtensa: support DMA to high memory
  Revert "xtensa: cache inquiry and unaligned cache handling functions"
  xtensa: drop unused sections and remapped reset handlers
  xtensa: fix secondary core boot in SMP
  xtensa: add FORCE_MAX_ZONEORDER to Kconfig
  xtensa: nommu: provide defconfig for de212 on kc705
  xtensa: nommu: xtfpga: add kc705 DTS
  xtensa: add de212 core variant
  xtensa: nommu: select HAVE_FUTEX_CMPXCHG
  xtensa: nommu: fix default memory start address
  xtensa: nommu: provide correct KIO addresses
  xtensa: nommu: fix USER_RING definition
  xtensa: xtfpga: fix integer overflow in TASK_SIZE
  xtensa: fix build for configs without cache options
  xtensa: fixes for configs without loop option

mm: make compound_head() robust

2015-11-07T01:50:42+00:00

Hugh has pointed that compound_head() call can be unsafe in some
context. There's one example:

	CPU0					CPU1

isolate_migratepages_block()
  page_count()
    compound_head()
      !!PageTail() == true
					put_page()
					  tail->first_page = NULL
      head = tail->first_page
					alloc_pages(__GFP_COMP)
					   prep_compound_page()
					     tail->first_page = head
					     __SetPageTail(p);
      !!PageTail() == true
    

The race is pure theoretical. I don't it's possible to trigger it in
practice. But who knows.

We can fix the race by changing how encode PageTail() and compound_head()
within struct page to be able to update them in one shot.

The patch introduces page->compound_head into third double word block in
front of compound_dtor and compound_order. Bit 0 encodes PageTail() and
the rest bits are pointer to head page if bit zero is set.

The patch moves page->pmd_huge_pte out of word, just in case if an
architecture defines pgtable_t into something what can have the bit 0
set.

hugetlb_cgroup uses page->lru.next in the second tail page to store
pointer struct hugetlb_cgroup. The patch switch it to use page->private
in the second tail page instead. The space is free since ->first_page is
removed from the union.

The patch also opens possibility to remove HUGETLB_CGROUP_MIN_ORDER
limitation, since there's now space in first tail page to store struct
hugetlb_cgroup pointer. But that's out of scope of the patch.

That means page->compound_head shares storage space with:

 - page->lru.next;
 - page->next;
 - page->rcu_head.next;

That's too long list to be absolutely sure, but looks like nobody uses
bit 0 of the word.

page->rcu_head.next guaranteed[1] to have bit 0 clean as long as we use
call_rcu(), call_rcu_bh(), call_rcu_sched(), or call_srcu(). But future
call_rcu_lazy() is not allowed as it makes use of the bit and we can
get false positive PageTail().

[1] http://lkml.kernel.org/g/20150827163634.GD4029@linux.vnet.ibm.com

Signed-off-by: Kirill A. Shutemov 
Acked-by: Michal Hocko 
Reviewed-by: Andrea Arcangeli 
Cc: Hugh Dickins 
Cc: David Rientjes 
Cc: Vlastimil Babka 
Acked-by: Paul E. McKenney 
Cc: Aneesh Kumar K.V 
Cc: Andi Kleen 
Cc: Christoph Lameter 
Cc: Joonsoo Kim 
Cc: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

xtensa: nommu: provide defconfig for de212 on kc705

2015-11-02T15:03:13+00:00

Signed-off-by: Max Filippov

rtmutex: Delete scriptable tester

2015-07-20T09:45:45+00:00

No one uses this anymore, and this is not the first time the
idea of replacing it with a (now possible) userspace side.
Lock stealing logic was removed long ago in when the lock
was granted to the highest prio.

Signed-off-by: Davidlohr Bueso 
Cc: Darren Hart 
Cc: Steven Rostedt 
Cc: Mike Galbraith 
Cc: Paul E. McKenney 
Cc: Sebastian Andrzej Siewior 
Cc: Davidlohr Bueso 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1435782588-4177-2-git-send-email-dave@stgolabs.net
Signed-off-by: Thomas Gleixner

xtensa: xtfpga: provide defconfig with audio subsystem

2015-02-07T09:52:12+00:00

This is the generic KC705 defconfig with all pieces of xtfpga audio
subsystem enabled: I2C, SPI and ASoC support, I2C master, SPI master,
clock synthesizer, I2S master, audio codec and audio card drivers.

Signed-off-by: Max Filippov

xtensa: disable link optimization

2014-12-16T07:47:24+00:00

The default linker behavior is to optimize identical literal values
and remove unnecessary overhead. However, because of a bug in the
linker, this currently results in an error ('call target out of range').

Disable link-time optimizations per default until there is a fix
for the linker and add the option to iss_defconfig.

Signed-off-by: Chris Zankel

xtensa: remove s6000 variant and s6105 platform

2014-10-21T09:29:01+00:00

The Stretch s6000 family support has been merged into mainline 5 years
ago. There appear to be no users of this code since nobody complained
that there is a merge error preventing compilation.

Apart from the s6105 IP camera reference design there are no s6000 devices
known to ever have run Linux and as the chips are out of production there
probably never will be. The successor s7000 no longer uses an Xtensa core
for the OS.

Let's remove the code until someone is found who actually needs it.

Signed-off-by: Daniel Glöckner 
Signed-off-by: Max Filippov

xtensa: xtfpga: add lx200 SMP DTS and defconfig

2014-10-21T09:28:43+00:00

This config allows running SMP-enabled bitstream on LX200 board.
NFS or FLASH rootfs, minimal debug, up to 4 cores.

Signed-off-by: Max Filippov

xtensa: xtfpga: add generic KC705 board config

2014-10-21T09:28:42+00:00

This config enables most important features, NFS or FLASH rootfs and
minimal debug.

Signed-off-by: Max Filippov

xtensa: remove orphan MATH_EMULATION symbol

2014-08-14T07:59:12+00:00

Signed-off-by: Max Filippov