On ppc, we emulate instructions that cause alignment exceptions.  If we are
single-stepping an instruction and it causes an alignment exception, we
will currently do the next instruction as well before taking the
single-step exception.  This patch fixes that, so we take the single-step
exception after emulating the instruction.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If we should happen to get an altivec assist exception while executing in
the kernel, we will currently try to handle it and fail, and end up oopsing
with (apparently) a segfault.  (An altivec assist exception occurs for
floating-point altivec instructions with denormalized inputs or outputs if
the altivec unit is in java mode.)

This patch checks explicitly if we are in user mode and prints a useful
message if not.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently the procedure in the ppc32 kernel that synchronizes the timebase
registers across an SMP powermac system does so by setting both timebases
to zero.  That is OK at boot but causes problems if done later.  So that we
can do hotplug CPU on these machines, this patch changes the code so it
reads the timebase from one CPU and transfers the value to the other CPU. 
(Hotplug CPU is needed for sleep (aka suspend to RAM) to work.)
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds interrupt acknowledge to the PPC4xx PIC enable_irq
implementation for level-sensitive IRQ sources.  This helps in cases when
enable/disable_irq is used in interrupt handlers for hardware, which
requires IRQ acknowledge to be issued from non-interrupt context (e.g. 
when actual ACK in device needs an I2C transaction).  For such strange
hardware, interrupt handler disables IRQ and defers actual ACK to some
other context.  When this happens, IRQ is enabled again.  For
level-sensitive sources we get spurious triggering right after IRQ is
enabled.  This patch fixes this.

Suggested by Tolunay Orkun <listmember@orkun.us>.
Signed-off-by: NEugene Surovegin <ebs@ebshome.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The code that went into arch/ppc/kernel/signal.c recently to handle process
freezing seems to contain a dubious assumption: that a process that calls
do_signal when PF_FREEZE is set will have entered the kernel because of a
system call.  This patch removes that assumption.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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!