We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:
git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_users);/mmget\(\1\);/'
git grep -l 'atomic_inc.*mm_users' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_users);/mmget\(\&\1\);/'
This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.
(Michal Hocko provided most of the kerneldoc comment.)
Link: http://lkml.kernel.org/r/20161218123229.22952-2-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/'
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/'
This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.
(Michal Hocko provided most of the kerneldoc comment.)
Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let the non boot cpus call into idle with the corresponding hotplug state, so
the hotplug core can handle the further bringup. That's a first step to
convert the boot side of the hotplugged cpus to do all the synchronization
with the other side through the state machine. For now it'll only start the
hotplug thread and kick the full bringup of the cpu.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Replace the deprecated atomic_{set,clear}_mask() usage with the now
ubiquous atomic_{or,andnot}() functions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit removes the open-coded CPU-offline notification with new
common code. This change avoids calling scheduler code using RCU from
an offline CPU that RCU is ignoring. This commit is compatible with
the existing code in not checking for timeout during a prior offline
for a given CPU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: <adi-buildroot-devel@lists.sourceforge.net>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
CC: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Commit 9a46ad6d6d "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Pull phase two of __cpuinit removal from Paul Gortmaker:
"With the __cpuinit infrastructure removed earlier, this group of
commits only removes the function/data tagging that was done with the
various (now no-op) __cpuinit related prefixes.
Now that the dust has settled with yesterday's v3.11-rc1, there
hopefully shouldn't be any new users leaking back in tree, but I think
we can leave the harmless no-op stubs there for a release as a
courtesy to those who still have out of tree stuff and weren't paying
attention.
Although the commits are against the recent tag to allow for minor
context refreshes for things like yesterday's v3.11-rc1~ slab content,
the patches have been largely unchanged for weeks, aside from such
trivial updates.
For detail junkies, the largely boring and mostly irrelevant history
of the patches can be viewed at:
http://git.kernel.org/cgit/linux/kernel/git/paulg/cpuinit-delete.git
If nothing else, I guess it does at least demonstrate the level of
involvement required to shepherd such a treewide change to completion.
This is the same repository of patches that has been applied to the
end of the daily linux-next branches for the past several weeks"
* 'cpuinit_phase2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (28 commits)
block: delete __cpuinit usage from all block files
drivers: delete __cpuinit usage from all remaining drivers files
kernel: delete __cpuinit usage from all core kernel files
rcu: delete __cpuinit usage from all rcu files
net: delete __cpuinit usage from all net files
acpi: delete __cpuinit usage from all acpi files
hwmon: delete __cpuinit usage from all hwmon files
cpufreq: delete __cpuinit usage from all cpufreq files
clocksource+irqchip: delete __cpuinit usage from all related files
x86: delete __cpuinit usage from all x86 files
score: delete __cpuinit usage from all score files
xtensa: delete __cpuinit usage from all xtensa files
openrisc: delete __cpuinit usage from all openrisc files
m32r: delete __cpuinit usage from all m32r files
hexagon: delete __cpuinit usage from all hexagon files
frv: delete __cpuinit usage from all frv files
cris: delete __cpuinit usage from all cris files
metag: delete __cpuinit usage from all metag files
tile: delete __cpuinit usage from all tile files
sh: delete __cpuinit usage from all sh files
...
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/blackfin uses of the __cpuinit macros from
all C files. Currently blackfin does not have any __CPUINIT used in
assembly files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
release boot lock earlier to let coreb do setup and calibrate
set coreb online later after initialization ready
add BFIN_IPI_NONE IPI type
drop unnecesarry smp_mb() and using atomic type
Signed-off-by: Steven Miao <realmz6@gmail.com>
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>
After use generic smp helpers, smp_mb() should be added to keep coherency.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Replace blackfin ipi message queue with generic smp helper function.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Link: http://lkml.kernel.org/r/20120420124557.717064871@linutronix.de
Preparatory patch to make the idle thread allocation for secondary
cpus generic.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
disable preemption when icache flush and use wait mode cross call, hold the msg
queue lock while handle cross function call to avoid overflow
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
move idle task point to percpu blackfin_cpudata and add smp_timer_broadcast
interface.
enable SUPPLE_1_WAKEUP and add BFIN_IPI_TIMER ipi support.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Make sure our smp_send_reschedule() implementation matches the
scheduler_ipi() callback so that it can kick the idle cpu.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the double fault data used at boot time into a single struct
which can then easily be addressed with indexed loads rather than having
to explicitly load multiple addresses.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
old cpu_xxx() APIs is planned to removed later. then, converted.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
These are only used in a few internal Blackfin places, so move the irq
prototypes out of the global header and into the internal irq one. No
functional changes other than shuffling locales.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
For future rework of try_to_wake_up() we'd like to push part of that
function onto the CPU the task is actually going to run on.
In order to do so we need a generic callback from the existing scheduler IPI.
This patch introduces such a generic callback: scheduler_ipi() and
implements it as a NOP.
BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions!
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
The recent commit (10774912647781) wasn't entirely correct. While
it fixed some issues, it introduced others. So pull in the fixes
from the public cache flush functions, and document why we need to
call things directly ourselves.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
In order to safely work around anomaly 05000491, we have to execute IFLUSH
from L1 instruction sram. The trouble with multi-core systems is that all
L1 sram is visible only to the active core. So we can't just place the
functions into L1 and call it directly. We need to setup a jump table and
place the entry point in external memory. This will call the right func
based on the active core.
In the process, convert from the manual relocation of a small bit of code
into Core B's L1 to the more general framework we already have in place
for loading arbitrary pieces of code into L1.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The smp_processor_id() API requires that preempt be disabled when calling
it, so make sure it is when we go to send messages to other processors.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Defer bfin_setup_caches(cpu) to avoid unexpected faults due to the cpu
state not yet being fully initialized.
Signed-off-by: steven miao <realmz6@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Currently, sending an interprocessor interrupt (IPI) requires building up
a message dynamically which means memory allocation. But often times, we
will want to send an IPI in low level contexts where allocation is not
possible which may lead to a panic(). So create a per-cpu static array
for the message queue and use that instead.
Further, while we have two supplemental interrupts, we are currently only
using one of them. So use the second one for the most common IPI message
of all -- smp_send_reschedule(). This avoids ugly contention for locks
which in turn would require an IPI message ...
In general, this improves SMP performance, and in some cases allows the
SMP port to work in places it wouldn't before. Such as the PREEMPT_RT
state where the slab is protected by a per-cpu spin lock. If the slab
kmalloc/kfree were to put the task to sleep, and that task was actually
the IPI handler, then the system falls down yet again.
After running some various stress tests on the system, the static limit
of 5 messages seems to work. On the off chance even this overflows, we
simply panic(), and we can review that scenario to see if the limit needs
to be increased a bit more.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This function takes an irq_handler_t function, but the prototype in
the header doesn't match the function definition. This is due to the
smp headers needing to avoid circular dependencies. So change the
function to take a simple pointer.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The cpu maps are defines provided by common linux/cpumask.h, not local
variables. So stop exporting them locally and include the right header
for their definition.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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>
This functions are implicitly called by core functions like cpu_relax(),
and since those functions may be called early on before common code has
initialized the per-cpu data area, we need to tweak the stats gathering.
Now the statistics are maintained in common bss which makes these funcs
safe to use as soon as the C runtime env is setup.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
SMP systems require per-cpu local clock event devices in order to enable
HRT support. One a BF561, we can use local core timer for this purpose.
Originally, there was one global core-timer clock event device set up for
core A.
To accomplish this feat, we need to split the gptimer0/core timer logic
so that each is a standalone clock event. There is no requirement that
we only have one clock event source anyways. Once we have this, we just
define per-cpu clock event devices for each local core timer.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Sometimes a SMP system will randomly panic at boot. This is due to caches
being out of sync when one core tries to signal the other. So when one
core calls another via IPI, flush the data caches.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
When testing PREEMPT_RT kernel on BF561-EZKit, the kernel blocks while
booting. When the kernel initializes the ethernet driver, it sleeps and
never wakes up.
The issue happens when the kernel waits for a timer for Core B to timeout
(the timers are per-cpu based: static DEFINE_PER_CPU(struct tvec_base *,
tvec_bases) = &boot_tvec_bases).
However, the ksoftirqd thread for Core B (note, the ksoftirqd thread is
also per-cpu based) cannot work properly, and the timers for Core B never
times out.
When ksoftirqd() for the first time runs on core B, it is possible core A
is still initializing core B (see smp_init() -> cpu_up() -> __cpu_up()).
So the "cpu_is_offline()" check may return true and ksoftirqd moves to
"wait_to_die".
So delay the core b start up until the per-cpu timers have been set up
fully.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
To set zeroes the sizeof the struct should be used rather
than sizeof the pointer, kzalloc does that.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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>
Check that the result of kmalloc is not NULL before passing it to other
functions.
In the first two cases, the new code returns -ENOMEM, which seems
compatible with what is done for similar functions for other architectures.
In the last two cases, the new code fails silently, ie just returns,
because the function has void return type.
The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression *x;
identifier f;
constant char *C;
@@
x = \(kmalloc\|kcalloc\|kzalloc\)(...);
... when != x == NULL
when != x != NULL
when != (x || ...)
(
kfree(x)
|
f(...,C,...,x,...)
|
*f(...,x,...)
|
*x->f
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
On Blackfin SMP, a per-cpu loops_per_jiffy is pointless since both cores
always run at the same CCLK. In addition, the current implementation has
flaws since the main consumer for loops_per_jiffy (asm/delay.h) uses the
global kernel loops_per_jiffy and not the per_cpu one. So punt all of the
per-cpu handling and go back to the global shared one.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
When a low priority interrupt (like ethernet) is triggered between 2 high
priority IPI messages, a deadlock in disable_irq() is hit by the second
IPI handler. This is because the second IPI message is queued within the
first IPI handler, but the handler doesn't process all messages, and new
ones are inserted rather than appended. So now we process all the pending
messages, and append new ones to the pending list.
URL: http://blackfin.uclinux.org/gf/tracker/5226
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The KGDB code uses this when switching processors to make sure the icache
is in a valid state.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The Per-processor Data Area isn't actually reserved by this function, and
all it ended up doing was issuing a printk(), so punt it.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Ingo Molnar