- fix lockup when switching from early console to real console
- make sysrq reliable
- fix panic, if sysrq is issued before console is opened
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A new born thread starts execution not in schedule but rather in
ret_from_fork which results in it bypassing the part of the code to
load a new context written in C which are the DSP context and the
userlocal register which Linux uses for the TLS pointer. Frequently
we were just getting away with this bug for a number of reasons:
o Real world application scenarios are very unlikely to use clone or fork
in blocks of DSP code.
o Linux by default runs the child process right after the fork, so the
child by luck will find all the right context in the DSP and userlocal
registers.
o So far the rdhwr instruction was emulated on all hardware so userlocal
wasn't getting referenced at all and the emulation wasn't suffering
from the issue since it gets it's value straight from the thread's
thread_info.
Fixed by moving the code to load the context from switch_to() to
finish_arch_switch which will be called by newborn and old threads.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Since Ingo's recent scheduler rewrite which was merged as commit
0437e109e1 sched_cacheflush is unused.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Which will cut down the cost of RDHWR $29 which is used to obtain the
TLS pointer and so far being emulated in software down to a single cycle
operation.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Recently a few direct accesses to the thread_info in the task structure snuck
back, so this wraps them with the appropriate wrapper.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tas() has no users, so get rid of it.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that finally all supported versions of binutils have functioning
support for .subsection use .subsection to tweak the branch prediction
I did not modify the R10000 errata variants because it seems unclear if
this will invalidate the workaround which actually relies on the cheesy
prediction of branch likely to cause a misspredict if the sc was
successful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This eleminates the need to include ptrace.h into system.h and fixes a
harmless namespace conflict on the PC symbol in bpck.c.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit. Since it is not currently used in the
kernel this patch removes it so that new code does not include it.
All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead. But this is
still moot since it is not used anyway.
Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add per-arch sched_cacheflush() which is a write-back cacheflush used by
the migration-cost calibration code at bootup time.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Instead of requiring architecture code to interact with the scheduler's
locking implementation, provide a couple of defines that can be used by the
architecture to request runqueue unlocked context switches, and ask for
interrupts to be enabled over the context switch.
Also replaces the "switch_lock" used by these architectures with an oncpu
flag (note, not a potentially slow bitflag). This eliminates one bus
locked memory operation when context switching, and simplifies the
task_running function.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Thomas Bogendoerfer