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Introduced by commit 25d67f860f3a ("bfin: Use generic idle loop").
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Link: http://lkml.kernel.org/r/20130321215234.014923303@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Commit 26bab0c ("blackfin idle: delete pm_idle") introduced the following
compile error:
arch/blackfin/kernel/process.c: In function ‘cpu_idle’:
arch/blackfin/kernel/process.c:83: error: ‘idle’ undeclared (first use in this function)
arch/blackfin/kernel/process.c:83: error: (Each undeclared identifier is reported only once
arch/blackfin/kernel/process.c:83: error: for each function it appears in.)
arch/blackfin/kernel/process.c:88: error: implicit declaration of function ‘idle’
This patch fixes it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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pm_idle is dead code on blackfin.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: uclinux-dist-devel@blackfin.uclinux.org
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.
For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.
This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.
Later, we'll add other information to the struct as it becomes
convenient.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Since nr_cpus_allowed is used outside of sched/rt.c and wants to be
used outside of there more, move it to a more natural site.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kr61f02y9brwzkh6x53pdptm@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This patch added bf60x to current blackfin kernel framework.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
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Disintegrate asm/system.h for Blackfin.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: uclinux-dist-devel@blackfin.uclinux.org
Signed-off-by: Bob Liu <lliubbo@gmail.com>
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Coccinelle based conversion.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Those two APIs were provided to optimize the calls of
tick_nohz_idle_enter() and rcu_idle_enter() into a single
irq disabled section. This way no interrupt happening in-between would
needlessly process any RCU job.
Now we are talking about an optimization for which benefits
have yet to be measured. Let's start simple and completely decouple
idle rcu and dyntick idle logics to simplify.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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It is assumed that rcu won't be used once we switch to tickless
mode and until we restart the tick. However this is not always
true, as in x86-64 where we dereference the idle notifiers after
the tick is stopped.
To prepare for fixing this, add two new APIs:
tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().
If no use of RCU is made in the idle loop between
tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
must instead call the new *_norcu() version such that the arch doesn't
need to call rcu_idle_enter() and rcu_idle_exit().
Otherwise the arch must call tick_nohz_enter_idle() and
tick_nohz_exit_idle() and also call explicitly:
- rcu_idle_enter() after its last use of RCU before the CPU is put
to sleep.
- rcu_idle_exit() before the first use of RCU after the CPU is woken
up.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:
- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.
There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.
Split this function into:
- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.
- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).
To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().
This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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Every callter (except kthread_bind) should use proper
set_cpus_allowed_ptr() APIs.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When apps run with their stack in L1, some system calls might be made
where a buffer is in the stack as an argument. So make sure the core
Blackfin access code does not reject this memory location.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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Rename h/w IRQ flags handling functions to be in line with what is expected for
the irq renaming patch. This renames local_*_hw() to hard_local_*() using the
following perl command:
perl -pi -e 's/local_irq_(restore|enable|disable)_hw/hard_local_irq_\1/ or s/local_irq_save_hw([_a-z]*)[(]flags[)]/flags = hard_local_irq_save\1()/' `find arch/blackfin/ -name "*.[ch]"`
and then fixing up asm/irqflags.h manually.
Additionally, arch/hard_local_save_flags() and arch/hard_local_irq_save() both
return the flags rather than passing it through the argument list.
Signed-off-by: David Howells <dhowells@redhat.com>
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Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mark arguments to certain system calls as being const where they should be but
aren't. The list includes:
(*) The filename arguments of various stat syscalls, execve(), various utimes
syscalls and some mount syscalls.
(*) The filename arguments of some syscall helpers relating to the above.
(*) The buffer argument of various write syscalls.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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We don't support core dumps (yet?), but this should make things easier.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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No point in returning to userspace just to have it immediately perform the
RTS step. We have to update the PC anyways, so do the RTS too.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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The access_ok() function did not accept ranges within the async banks
which made it impossible to do XIP in flash. Fixing that also showed
that the current bfin_mem_access_type() code did not work with accesses
that spanned async banks (like a file system). So split out and fix the
async bank checks so that all these scenarios work as expected.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'bkl-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
mn10300: Remove the BKL from sys_execve
m68knommu: Remove the BKL from sys_execve
m68k: Remove the BKL from sys_execve
h83000: Remove BKL from sys_execve
frv: Remove the BKL from sys_execve
blackfin: Remove the BKL from sys_execve
um: Remove BKL from mmapper
um: Remove BKL from random
s390: Remove BKL from prng
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Commit d5ce528c8e46fa5afb9 (Blackfin: convert irq/process to asm-generic)
incorrectly merged the smp and non-smp cases of start_thread() causing the
L1 stack to be setup on the SMP port instead of the UP port.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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This looks like a cut-and-paste job. For example, compare this
function to sys_execve in arch/x86/kernel/process_64.c and it is
almost line by line the same, except the one in x86 nolonger has the
big kernel lock. All of the functions called between the lock are
generic and not specific to blackfin - thus, I believe it is safe to
remove the bkl here.
Signed-off-by: John Kacur <jkacur@redhat.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <alpine.LFD.2.00.0910130007240.3658@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Bill Gatliff & David Brownell pointed out we were missing some
copyrights, and licensing terms in some of the files in
./arch/blackfin, so this fixes things, and cleans them up.
It also removes:
- verbose GPL text(refer to the top level ./COPYING file)
- file names (you are looking at the file)
- bug url (it's in the ./MAINTAINERS file)
- "or later" on GPL-2, when we did not have that right
It also allows some Blackfin-specific assembly files to be under a BSD
like license (for people to use them outside of Linux).
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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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>
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Rather than assume Core B is always run with caches turned on, let people
load into any of the on-chip memory regions. It is their business how the
SRAM/Cache regions are utilized, so don't prevent them from being able to
load into them.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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The kgdb (in multiple places) and traps code developed pretty much
identical checks for how to access different regions of the Blackfin
memory map, but each wasn't 100%, so unify them to avoid duplication,
bitrot, and bugs with edge cases.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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There is no need for the L1 attribute to be on the prototype of the
access_ok() function as all consumers of the function do not care where it
lives -- they'll always use pcrel calls to get to it. This prevents
pointless recompiles of most of the system when this config option changes.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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* git://git.infradead.org/mtd-2.6: (53 commits)
[MTD] struct device - replace bus_id with dev_name(), dev_set_name()
[MTD] [NOR] Fixup for Numonyx M29W128 chips
[MTD] mtdpart: Make ecc_stats more realistic.
powerpc/85xx: TQM8548: Update DTS file for multi-chip support
powerpc: NAND: FSL UPM: document new bindings
[MTD] [NAND] FSL-UPM: Add wait flags to support board/chip specific delays
[MTD] [NAND] FSL-UPM: add multi chip support
[MTD] [NOR] Add device parent info to physmap_of
[MTD] [NAND] Add support for NAND on the Socrates board
[MTD] [NAND] Add support for 4KiB pages.
[MTD] sysfs support should not depend on CONFIG_PROC_FS
[MTD] [NAND] Add parent info for CAFÉ controller
[MTD] support driver model updates
[MTD] driver model updates (part 2)
[MTD] driver model updates
[MTD] [NAND] move gen_nand's probe function to .devinit.text
[MTD] [MAPS] move sa1100 flash's probe function to .devinit.text
[MTD] fix use after free in register_mtd_blktrans
[MTD] [MAPS] Drop now unused sharpsl-flash map
[MTD] ofpart: Check name property to determine partition nodes.
...
Manually fix trivial conflict in drivers/mtd/maps/Makefile
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First argument unused since 2.3.11.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix a bad dependency in the Blackfin code on a RomFS config symbol that doesn't
exist upstream.
Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
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[Mike Frysinger <vapier.adi@gmail.com>:
- handle bf531/bf532/bf534/bf536 variants in ipipe.h
- cleanup IPIPE logic for bfin_set_irq_handler()
- cleanup ipipe asm code a bit and add missing ENDPROC()
- simplify IPIPE code in trap_c
- unify some of the IPIPE code and fix style
- simplify DO_IRQ_L1 handling with ipipe code
- revert IRQ_SW_INT# addition from ipipe merge
- remove duplicate get_{c,s}clk() prototypes
]
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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1. Use inline get_l1_... functions instead of macro
2. Fix compile issue about smp barrier functions
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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management code
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to Blackfin kernel and memory management code
Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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- kernel_thread
- irq_flags
- checksum
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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Allow user space to access L2 SRAM.
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:
scheduler switch to idle task
enable interrupts
Window starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick
----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.
The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.
Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.
cpu_idle()
{
preempt_disable();
while(1) {
tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
are in the idle loop
while (!need_resched())
halt();
tick_nohz_restart_sched_tick(); <- disables NOHZ mode
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
In hindsight we should have done this forever, but ...
/me grabs a large brown paperbag.
Debugged-by: Jack Ren <jack.ren@marvell.com>,
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The following cleanup patch:
add __user markings to a few userspace system functions
mysteriously added a "&" operator that doesn't belong in there, breaking the
atomic sections code.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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Previously, init failed to do anything meaningful;
it turns out that the reason is that FD-PIC has a readonly data
section which can be located in the XIP filesystem, and various address checks
in the kernel reject such addresses for syscall arguments. Hence, init's
execve ("/bin/sh", ...)
failed with error code EFAULT.
There's room for improvement here: in case people want to have filesystems
on flash rather than in main memory, _access_ok should be modified to
allow this.
This bug fix is also dedicated to Michael Hennerich.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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and a few userspace system functions
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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This patch enables Hight-Res Timers and tickless kernel
Signed-off-by: Vitja Makarov <vitja.makarov@gmail.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
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