The earlier approach required two scheduling-clock ticks to note an
preemptable-RCU quiescent state in the situation in which the
scheduling-clock interrupt is unlucky enough to always interrupt an
RCU read-side critical section.

With this change, the quiescent state is instead noted by the
outermost rcu_read_unlock() immediately following the first
scheduling-clock tick, or, alternatively, by the first subsequent
context switch.  Therefore, this change also speeds up grace
periods.
Suggested-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
LKML-Reference: <12528585111945-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Check to make sure that there are no blocked tasks for the previous
grace period while initializing for the next grace period, verify
that rcu_preempt_qs() is given the correct CPU number and is never
called for an offline CPU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
LKML-Reference: <12528585111986-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

To quote Valdis:

    This leaves somebody who has a laptop wondering which
    choice is best for a system with only one or two cores that
    has CONFIG_PREEMPT defined. One choice says it scales down
    nicely, the other explicitly has a 'depends on PREEMPT'
    attached to it...

So add "scales down nicely" to TREE_PREEMPT_RCU to match that of
TREE_RCU.
Suggested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12528585112362-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

rcutorture already delays readers, but never for long enough to
make RCU force a quiescent state.  Add an occasional delay of
50ms.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
LKML-Reference: <12524504772607-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Prior implementations initialized the root and any internal
nodes without holding locks, then initialized the leaves
holding locks.

This is a false economy, as the leaf nodes will usually greatly
outnumber the root and internal nodes.  Acquiring locks on all
nodes is conceptually much simpler as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
LKML-Reference: <12524504773190-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Without this patch, tasks preempted in RCU read-side critical
sections can fail to block the grace period, given that
rnp->gpnum is used to determine which rnp->blocked_tasks[]
element the preempted task is enqueued on.

Before the patch, rnp->gpnum is always zero, so preempted tasks
are always enqueued on rnp->blocked_tasks[0], which is correct
only when the current CPU has not checked into the current
grace period and the grace-period number is even, or,
similarly, if the current CPU -has- checked into the current
grace period and the grace-period number is odd.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
LKML-Reference: <12524504771622-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  amd64_edac: check NB MCE bank enable on the current node properly
  amd64_edac: Rewrite unganged mode code of f10_early_channel_count
  amd64_edac: cleanup amd64_check_ecc_enabled
  x86, EDAC: Provide function to return NodeId of a CPU
  amd64_edac: build driver only on AMD hardware

* 'for-linus' of git://oss.sgi.com/xfs/xfs: (39 commits)
  xfs: includecheck fix for fs/xfs/xfs_iops.c
  xfs: switch to seq_file
  xfs: Record new maintainer information
  xfs: use correct log reservation when handling ENOSPC in xfs_create
  xfs: xfs_showargs() reports group *and* project quotas enabled
  xfs: un-static xfs_inobt_lookup
  xfs: actually enable the swapext compat handler
  xfs: simplify xfs_trans_iget
  xfs: merge fsync and O_SYNC handling
  xfs: speed up free inode search
  xfs: rationalize xfs_inobt_lookup*
  xfs: untangle xfs_dialloc
  xfs: factor out debug checks from xfs_dialloc and xfs_difree
  xfs: improve xfs_inobt_update prototype
  xfs: improve xfs_inobt_get_rec prototype
  xfs: factor out inode initialisation
  fs/xfs: Correct redundant test
  xfs: remove XFS_INO64_OFFSET
  un-static xfs_read_agf
  xfs: add more statics & drop some unused functions
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (75 commits)
  Blackfin: update ftrace for latest toolchain
  Blackfin: fix elf_fpregset_t definition
  Blackfin: unify cache init functions
  Blackfin: swap clocksource ratings for gptimer/cycles
  Blackfin: update ftrace_push_return_trace() breakage
  Blackfin: update cm board resources
  Blackfin: cm-bf537u: split board from cm-bf537e
  Blackfin: bf538-ezkit: add SPI IRQ resources
  Blackfin: increase default async timings for parallel flashes
  Blackfin: add ICPLB coverage for async banks
  Blackfin: use KERN_ALERT in all kgdb_test output
  Blackfin: fix BF54x SPI CS resources
  Blackfin: fix typo in isram_write()
  Blackfin: bf537-stamp: add adp5588 gpio resources
  Blackfin: add some isram-driver self tests
  Blackfin: workaround anomaly 05000283
  Blackfin: fix spelling in a few comments
  Blackfin: use raw_smp_processor_id() in exception code
  Blackfin: remove useless duplicated assignment in gpio code
  Blackfin: Fix link errors with binutils 2.19 and GCC 4.3
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: (53 commits)
  m68knommu: Make PAGE_SIZE available to assembly files.
  m68knommu: fix ColdFire definition of CLOCK_TICK_RATE
  m68knommu: set multi-function pins for ethernet when enabled
  m68knommu: remove special interrupt handling code for ne2k support
  m68knommu: relax IO_SPACE_LIMIT setting
  m68knommu: remove ColdFire direct interrupt register access
  m68knommu: create a speciailized ColdFire 5272 interrupt controller
  m68knommu: add support for second interrupt controller of ColdFire 5249
  m68knommu: clean up old ColdFire timer irq setup
  m68knommu: map ColdFire interrupts to correct masking bits
  m68knommu: clean up ColdFire 532x CPU timer setup
  m68knommu: simplify ColdFire "timers" clock initialization
  m68knommu: support code to mask external interrupts on old ColdFire CPU's
  m68knommu: merge old ColdFire interrupt controller masking macros
  m68knommu: remove duplicate ColdFire mcf_autovector() code
  m68knommu: move ColdFire INTC definitions to new include file
  m68knommu: mask off all interrupts in ColdFire intc-simr controller
  m68knommu: remove timer device interrupt setup for ColdFire 532x
  m68knommu: remove interrupt masking from ColdFire pit timer
  m68knommu: remove unecessary interrupt level setting in ColdFire 520x setup
  ...

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (lm85) Don't bind to Winbond/Nuvoton WPCD377I
  hwmon: (pcf8591) Documentation clean-ups
  hwmon: Clearly mark ACPI drivers as such
  hwmon: Use resource_size
  hwmon: Include <linux/io.h> instead of <asm/io.h>
  hwmon: (tmp421) Add documentation
  hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips
  hwmon-vid: Ignore 6th VID pin of AMD family 0Fh processors
  hwmon: (asus_atk0110) Add maintainer information
  hwmon: (abituguru3) Support multiple DMI strings per chip ID

* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
  uwb: avoid radio controller reset loops
  uwb: stop uwbd thread if rc->start() fails
  uwb: handle radio controller events with out-of-range IDs correctly

The mcount support that was finally added to the Blackfin gcc port isn't
exactly the same as what ftrace was developed against.  Now that the final
gcc version is in place, update the ftrace code to match.

While updating this, fix the swapped arguments to the tracer (signature is
(ip, parent_ip) while we were passing (parent_ip, ip)).
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The elf_fpregset_t type relied on an empty struct in the asm/user.h, but
the transition to asm-generic/user.h dropped that empty struct.  Rather
than restore this useless struct, define the only user (elf_fpregset_t)
as an empty struct itself.  This fixes building when ELF dump support is
enabled.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The CPLB implementations (mpu/nompu) had exact copies of the cacheinit
code.  Even the i/d cache functions are largely the same.  So unify them
both in the common kernel cache code.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The cycles clocksource is a higher resolution than the gptimer one, so
make sure the ratings field reflects this.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Commit 71e308a2 updated ftrace_push_return_trace() prototype but didn't
update the Blackfin ftrace code, so things broke.  Since we don't support
the new stuff yet, call it with stub values.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Harald Krapfenbauer <Harald.Krapfenbauer@bluetechnix.at>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The cm-bf537u module, while similar to the cm-bf537e, is different enough
to warrant its own resources.  It has a USB controller but no PHY.
Signed-off-by: Harald Krapfenbauer <Harald.Krapfenbauer@bluetechnix.at>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The default async timings are a little too fast for the parallel flash
that is attached by default to the async banks.  So slow things down a bit
so accessing the hardware is stable.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

When doing XIP, we need to execute out of the async banks, so we need
ICPLBs to allow this.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Most messages are already using KERN_ALERT, so be consistent to make
things easier to check with test scripts.
Signed-off-by: Mingquan Pan <grace.pan@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The BF54x has three slave select signals for SPI0/SPI1, not eight.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The DTEST write bit is 2, not 1.  Improve comments in the related macro
while we're here.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

For the adp5588 GPIO daughter card.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Make it easy to figure out if code changes here are correct.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Make sure our interrupt entry code with exact hardware errors handles
anomaly 05000283 (infinite stall in system MMR kill) so we don't stall
while under load.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

When preempt debugging is enabled, smp_processor_id() may utilize the
"current" structure.  This may not be safe to access under all exceptions
due to it being in dynamically allocated memory.  So in exception code,
make sure we use raw_smp_processor_id() instead to get at the real value
directly.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Not sure whether this has been reported/fixed before.

Today I built a Blackfin tool-chain from scratch for -tip testing,
and it triggers:

 arch/blackfin/kernel/vmlinux.lds:1238: undefined section `.data_a_l1' referenced in expression

and:

 arch/blackfin/kernel/vmlinux.lds:1238: undefined section `.text_data_l1'
referenced in expression

Now i dont have any way to test this linker script, but it now at
least builds fine after fixing what appears to be typos in those
assert statements.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The majority of the time we are returning to user space, it is not in the
fixed atomic code region.  So rather than branch to a function where we
check the PC and return, do the check inline and branch only when needed.

Also, tweak some of the fixed code handling based on assumptions we are
aware of but cannot be expressed in C.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The ASoC drivers have dropped the redundant "-spi" suffix in the driver
name, so update the board resources accordingly.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

No one uses these functions, and some are duplicate of existing C code.  So
just punt the whole thing.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

These hardware devices are dead and the drivers never cleaned up/merged,
so punt the useless board resource info.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Since the exception handler cannot cause exceptions, we cannot trace it
without easily causing double faults and crashing the system.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The BF522 and BF523 had their real max VCO values swapped.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

We have an item to get this fixed, but in the mean time, disable selection
via Kconfig dependencies.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>