linux.git/arch/powerpc/kernel/entry_32.S, branch v2.6.19

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

powerpc: Use correct sequence for putting CPU into nap mode

2006-04-18T11:49:11+00:00

We weren't using the recommended sequence for putting the CPU into
nap mode.  When I changed the idle loop, for some reason 7447A cpus
started hanging when we put them into nap mode.  Changing to the
recommended sequence fixes that.

The complexity here is that the recommended sequence is a loop that
keeps putting the cpu back into nap mode.  Clearly we need some way
to break out of the loop when an interrupt (external interrupt,
decrementer, performance monitor) occurs.  Here we use a bit in
the thread_info struct to indicate that we need this, and the exception
entry code notices this and arranges for the exception to return
to the value in the link register, thus breaking out of the loop.
We use a new `local_flags' field in the thread_info which we can
alter without needing to use an atomic update sequence.

The PPC970 has the same recommended sequence, so we do the same thing
there too.

This also fixes a bug in the kernel stack overflow handling code on
32-bit, since it was causing a value that we needed in a register to
get trashed.

Signed-off-by: Paul Mackerras

powerpc: Unify the 32 and 64 bit idle loops

2006-03-27T04:03:03+00:00

This unifies the 32-bit (ARCH=ppc and ARCH=powerpc) and 64-bit idle
loops.  It brings over the concept of having a ppc_md.power_save
function from 32-bit to ARCH=powerpc, which lets us get rid of
native_idle().  With this we will also be able to simplify the idle
handling for pSeries and cell.

Signed-off-by: Paul Mackerras

powerpc: Fix various syscall/signal/swapcontext bugs

2006-03-08T02:24:22+00:00

A careful reading of the recent changes to the system call entry/exit
paths revealed several problems, plus some things that could be
simplified and improved:

* 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit
  path, so it was only doing anything with it once it saw some other
  bit being set.  In other words, the noerror behaviour would apply to
  the next system call where we had to reschedule or deliver a signal,
  which is not necessarily the current system call.

* 32-bit wasn't doing the call to ptrace_notify in the syscall exit
  path when the _TIF_SINGLESTEP bit was set.

* _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and
  _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set
  by system calls.  I took it out of _TIF_USER_WORK_MASK.

* On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers
  to be restored (unless perhaps a signal was delivered or the syscall
  was traced or single-stepped).  Thus the non-volatile registers
  weren't restored on exit from a signal handler.  We probably got
  away with it mostly because signal handlers written in C wouldn't
  alter the non-volatile registers.

* On 32-bit I simplified the code and made it more like 64-bit by
  making the syscall exit path jump to ret_from_except to handle
  preemption and signal delivery.

* 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was
  set - but I think because of that 32-bit was actually restoring the
  non-volatile registers on exit from a signal handler.

* I changed the order of enabling interrupts and saving the
  non-volatile registers before calling do_syscall_trace_leave; now we
  enable interrupts first.

Signed-off-by: Paul Mackerras

[PATCH] TIF_RESTORE_SIGMASK support for arch/powerpc

2006-01-19T03:20:30+00:00

Implement the TIF_RESTORE_SIGMASK flag in the new arch/powerpc kernel, for
both 32-bit and 64-bit system call paths.

Signed-off-by: David Woodhouse 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] powerpc: Cleanup LOADADDR etc. asm macros

2006-01-13T10:16:23+00:00

This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*).  The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation.  The new macros and their semantics are described in the
comments in ppc_asm.h.

In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC.  Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.

Signed-off-by: David Gibson 
Signed-off-by: Paul Mackerras

[PATCH] Fix code that saves NVGPRS in 32-bit signal frame

2006-01-09T03:50:48+00:00

On Thu, 2005-11-24 at 12:51 +0000, David Woodhouse wrote:
> Somehow this one slipped through the cracks; when we ended up in
> do_signal() on a 32-bit kernel but without having the caller-saved
> registers into the regs, we didn't set the TIF_SAVE_NVGPRS flag to
> ensure they got saved later.

Oh, and if we actually set the flag, then we fairly quickly find out
that I was a bit overzealous in copying code from entry_64.S ... :)

Signed-off-by: David Woodhouse 
Signed-off-by: Paul Mackerras

[PATCH] syscall entry/exit revamp

2006-01-09T03:49:01+00:00

This cleanup patch speeds up the null syscall path on ppc64 by about 3%,
and brings the ppc32 and ppc64 code slightly closer together.

The ppc64 code was checking current_thread_info()->flags twice in the
syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling
interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after
disabling interrupts. Now we do the same as ppc32 -- check the flags
only once in the fast path, and re-enable interrupts if necessary in the
ptrace case.

The patch abolishes the 'syscall_noerror' member of struct thread_info
and replaces it with a TIF_NOERROR bit in the flags, which is handled in
the slow path. This shortens the syscall entry code, which no longer
needs to clear syscall_noerror.

The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow
path to save the non-volatile GPRs into a signal frame. This removes the
need for the assembly wrappers around sys_sigsuspend(),
sys_rt_sigsuspend(), et al which existed solely to save those registers
in advance. It also means I don't have to add new wrappers for ppoll()
and pselect(), which is what I was supposed to be doing when I got
distracted into this...

Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit
directly into a signal handler (as required by sigsuspend et al) by
introducing a TIF_RESTOREALL flag which causes _all_ the registers to be
reloaded from the pt_regs by taking the ret_from_exception path, instead
of the normal syscall exit path which stomps on the callee-saved GPRs.

It appears to pass an LTP test run on ppc64, and passes basic testing on
ppc32 too. Brief tests of ptrace functionality with strace and gdb also
appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :)

Signed-off-by: David Woodhouse 
Signed-off-by: Paul Mackerras

powerpc: Rename asm offset TRAP to _TRAP for 32-bit

2005-10-28T12:45:25+00:00

... for consistency with 64-bit.

Signed-off-by: Paul Mackerras

powerpc: Merge rtas.c into arch/powerpc/kernel

2005-10-26T07:05:24+00:00

This splits arch/ppc64/kernel/rtas.c into arch/powerpc/kernel/rtas.c,
which contains generic RTAS functions useful on any CHRP platform,
and arch/powerpc/platforms/pseries/rtas-fw.[ch], which contain
some pSeries-specific firmware flashing bits.  The parts of rtas.c
that are to do with pSeries-specific error logging are protected
by a new CONFIG_RTAS_ERROR_LOGGING symbol.  The inclusion of rtas.o
is controlled by the CONFIG_PPC_RTAS symbol, and the relevant
platforms select that.

Signed-off-by: Paul Mackerras