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  1. 03 12月, 2015 1 次提交
    • W
      ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers · 40ee068e
      由 Will Deacon 提交于 
      Under some unusual context-switching patterns, it is possible to end up
with multiple threads from the same mm running concurrently with
different ASIDs:

1. CPU x schedules task t with mm p containing ASID a and generation g
   This task doesn't block and the CPU doesn't context switch.
   So:
     * per_cpu(active_asid, x) = {g,a}
     * p->context.id = {g,a}

2. Some other CPU generates an ASID rollover. The global generation is
   now (g + 1). CPU x is still running t, with no context switch and
   so per_cpu(reserved_asid, x) = {g,a}

3. CPU y schedules task t', which shares mm p with t. The generation
   mismatches, so we take the slowpath and hit the reserved ASID from
   CPU x. p is then updated so that p->context.id = {g + 1,a}

4. CPU y schedules some other task u, which has an mm != p.

5. Some other CPU generates *another* CPU rollover. The global
   generation is now (g + 2). CPU x is still running t, with no context
   switch and so per_cpu(reserved_asid, x) = {g,a}.

6. CPU y once again schedules task t', but now *fails* to hit the
   reserved ASID from CPU x because of the generation mismatch. This
   results in a new ASID being allocated, despite the fact that t is
   still running on CPU x with the same mm.

Consequently, TLBIs (e.g. as a result of CoW) will not be synchronised
between the two threads.

This patch fixes the problem by updating all of the matching reserved
ASIDs when we hit on the slowpath (i.e. in step 3 above). This keeps
the reserved ASIDs in-sync with the mm and avoids the problem.

Cc: <stable@vger.kernel.org>
Reported-by: NTony Thompson <anthony.thompson@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      40ee068e
  3. 29 11月, 2015 1 次提交
    • A
      ARM: 8454/1: OF implies OF_FLATTREE · aa7d5f18
      由 Arnd Bergmann 提交于 
      On the ARM architecture, individual platforms select CONFIG_USE_OF if they
need it, but all device tree code is keyed off CONFIG_OF. When building
a platform without DT support and manually enabling CONFIG_OF, we now
get a number of build errors, e.g.

arch/arm/kernel/devtree.c: In function 'setup_machine_fdt':
arch/arm/kernel/devtree.c:215:19: error: implicit declaration of function 'early_init_dt_verify' [-Werror=implicit-function-declaration]

We could now try to separate the use case of booting from DT vs. the
case of using the dynamic implementation, but that seems more complicated
than it can gain us.

This simply changes the ARM Kconfig file to always enable OF_RESERVED_MEM
and OF_EARLY_FLATTREE when CONFIG_OF is enabled. These options add a little
extra code when we just want the dynamic OF implementation, but that seems
like a rather obscure case, and this version solves all CONFIG_OF related
randconfig regressions.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 0166dc11 ("of: make CONFIG_OF user selectable")
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      aa7d5f18
  5. 18 11月, 2015 1 次提交
  7. 10 11月, 2015 1 次提交
  9. 07 11月, 2015 2 次提交
    • M
      mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep... · d0164adc
      由 Mel Gorman 提交于 
      mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d0164adc
    • S
      Revert "ARM: dts: twl4030: Add iio properties for bci subnode" · 829a7da0
      由 Sebastian Reichel 提交于 
      This reverts commit af19161a,
which breaks the omap3 device tree build due to a wrong reference.

I accidently queued this change via the power supply subsystem while
telling Marek at the same time, that it should go through Tony.
Following that I did miss Stephen's messages about the build failure in
linux-next and since he switched to merging an older snapshot nobody
else noticed the problem in my tree. I didn't notice myself, since I
did not build any device tree files assuming none have changed by me.
Signed-off-by: NSebastian Reichel <sre@kernel.org>
Reported-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NTony Lindgren <tony@atomide.com>
      829a7da0
  11. 06 11月, 2015 1 次提交
    • A
      uaccess: reimplement probe_kernel_address() using probe_kernel_read() · 0ab32b6f
      由 Andrew Morton 提交于 
      probe_kernel_address() is basically the same as the (later added)
probe_kernel_read().

The return value on EFAULT is a bit different: probe_kernel_address()
returns number-of-bytes-not-copied whereas probe_kernel_read() returns
-EFAULT.  All callers have been checked, none cared.

probe_kernel_read() can be overridden by the architecture whereas
probe_kernel_address() cannot.  parisc, blackfin and um do this, to insert
additional checking.  Hence this patch possibly fixes obscure bugs,
although there are only two probe_kernel_address() callsites outside
arch/.

My first attempt involved removing probe_kernel_address() entirely and
converting all callsites to use probe_kernel_read() directly, but that got
tiresome.

This patch shrinks mm/slab_common.o by 218 bytes.  For a single
probe_kernel_address() callsite.

Cc: Steven Miao <realmz6@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0ab32b6f
  13. 03 11月, 2015 4 次提交
  15. 02 11月, 2015 2 次提交
  17. 31 10月, 2015 2 次提交
  19. 29 10月, 2015 1 次提交
  21. 28 10月, 2015 2 次提交
  23. 27 10月, 2015 5 次提交
    • P
      ARM: DTS: am437x: Use the new DT bindings for the eDMA3 · e3faf2b8
      由 Peter Ujfalusi 提交于 
      Switch to use the ti,edma3-tpcc and ti,edma3-tptc binding for the eDMA3 and
enable the DMA even crossbar with ti,am335x-edma-crossbar.
With the new bindings boards can customize and tweak the DMA channel
priority to match their needs. With the new binding the memcpy is safe
to be used since with the old binding it was not possible for a driver
to know which channel is allowed to be used as non HW triggered channel.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>
      e3faf2b8
    • P
      ARM: DTS: am33xx: Use the new DT bindings for the eDMA3 · d871cd2e
      由 Peter Ujfalusi 提交于 
      Switch to use the ti,edma3-tpcc and ti,edma3-tptc binding for the eDMA3 and
enable the DMA even crossbar with ti,am335x-edma-crossbar.
With the new bindings boards can customize and tweak the DMA channel
priority to match their needs. With the new binding the memcpy is safe
to be used since with the old binding it was not possible for a driver
to know which channel is allowed to be used as non HW triggered channel.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>
      d871cd2e
    • M
      ARM: dts: uniphier: add outer cache controller nodes · 7c62f299
      由 Masahiro Yamada 提交于 
      Add L2 cache controller nodes for all the UniPhier SoC DTSI.
Also, add an L3 cache controller node for PH1-Pro5 DTSI.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>
      7c62f299
    • M
      ARM: uniphier: rework SMP operations to use trampoline code · b1e4006a
      由 Masahiro Yamada 提交于 
      The complexity of the boot sequence of UniPhier SoC family is
a PITA due to the following hardware limitations:

[1] No dedicated on-chip SRAM
SoCs in general have small SRAM, on which a tiny firmware or a boot
loader can run before SDRAM is initialized.  As UniPhier SoCs do not
have any dedicated SRAM accessible from CPUs, the locked outer cache
is used instead.  Due to the ARM specification, to have access to
the outer cache, the MMU must be enabled.  This is done for all CPU
cores by the program hard-wired in the boot ROM.  The boot ROM code
loads a small amount of program (this is usually SPL of U-Boot) from
a non-volatile device onto the locked outer cache, and the primary
CPU jumps to it.  The secondary CPUs stay in the boot ROM until they
are kicked by the primary CPU.

[2] CPUs can not directly jump to SDRAM address space
As mentioned above, the MMU is enable for all the CPUs with the page
table hard-wired in the boot ROM.  Unfortunately, the page table only
has minimal sets of valid sections; all the sections of SDRAM address
space are zero-filled.  That means all the CPUs, including secondary
ones, can not jump directly to SDRAM address space.  So, the primary
CPU must bring up secondary CPUs to accessible address mapped onto
the outer cache, then again kick them to SDRAM address space.

Before this commit, this complex task was done with help of a boot
loader (U-Boot); U-Boot SPL brings up the secondary CPUs to the entry
of U-Boot SPL and they stay there until they are kicked by Linux.
This is not nice because a boot loader must put the secondary CPUs
into a certain state expected by the kernel.  It makes difficult to
port another boot loader because the boot loader and the kernel must
work in sync to wake up the secondary CPUs.

This commit reworks the SMP operations so that they do not rely on
particular boot loader implementation; the SMP operations (platsmp.c)
put trampoline code (headsmp.S) on a locked way of the outer cache.
The secondary CPUs jump from the boot ROM to secondary_entry via the
trampoline code.  The boot loader no longer needs to take care of SMP.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>
      b1e4006a
    • M
      ARM: uniphier: add outer cache support · e7ecbc05
      由 Masahiro Yamada 提交于 
      This commit adds support for UniPhier outer cache controller.
All the UniPhier SoCs are equipped with the L2 cache, while the L3
cache is currently only integrated on PH1-Pro5 SoC.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>
      e7ecbc05
  25. 26 10月, 2015 7 次提交
  27. 24 10月, 2015 10 次提交