This adds a cputable function pointer for the CPU-side machine
check handling. The semantic is still the same as the old one,
the one in ppc_md. overrides the one in cputable, though
ultimately we'll want to change that so the CPU gets first.

This removes CONFIG_440A which was a problem for multiplatform
kernels and instead fixes up the IVOR at runtime from a setup_cpu
function. The "A" version of the machine check also tweaks the
regs->trap value to differenciate the 2 versions at the C level.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

This folds back the ptrace-common.h bits back into ptrace.c and removes
that file. The FSL SPE bits from ptrace-ppc32.h are folded back in as
well.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The powerpc ptrace interface is dodgy at best. We have defined our
"own" versions of GETREGS/SETREGS/GETFPREGS/SETFPREGS that strangely
take arguments in reverse order from other archs (in addition to having
different request numbers) and have subtle issue, like not accessing
all of the registers in their respective categories.

This patch moves the implementation of those to a separate function
in order to facilitate their deprecation in the future, and provides
new ptrace requests that mirror the x86 and sparc ones and use the
same numbers:

   PTRACE_GETREGS    : returns an entire pt_regs (the whole thing,
                       not only the 32 GPRs, though that doesn't
                       include the FPRs etc... There's a compat version
                       for 32 bits that returns a 32 bits compatible
                       pt_regs (44 uints)

   PTRACE_SETREGS    : sets an entire pt_regs (the whole thing,
                       not only the 32 GPRs, though that doesn't
                       include the FPRs etc... Some registers cannot be
                       written to and will just be dropped, this is the
                       same as with POKEUSR, that is anything above MQ
                       on 32 bits and CCR on 64 bits. There is a compat
                       version as well.

   PTRACE_GETFPREGS  : returns all the FP registers -including- the FPSCR
                       that is 33 doubles (regardless of 32/64 bits)

   PTRACE_SETFPREGS  : sets all the FP registers -including- the FPSCR
                       that is 33 doubles (regardless of 32/64 bits)

And two that only exist on 64 bits kernels:

   PTRACE_GETREGS64  : Same as PTRACE_GETREGS, except there is no compat
                       function, a 32 bits process will obtain the full 64
                       bits registers

   PTRACE_SETREGS64  : Same as PTRACE_SETREGS, except there is no compat
                       function, a 32 bits process will set the full 64
                       bits registers

The two later ones makes things easier to have a 32 bits debugger on a
64 bits program (or on a 32 bits program that uses the full 64 bits of
the GPRs, which is possible though has issues that will be fixed in a
later patch).

Finally, while at it, the patch removes a whole bunch of code duplication
between ptrace32.c and ptrace.c, in large part by having the former call
into the later for all requests that don't need any special "compat"
treatment.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add the regs_return_value() macro to extract the return value in an
architecture agnostic manner, given the pt_regs.

Other architecture maintainers may want to add similar helpers.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Ulrich Weigand found a bug with the current version of the
asm-powerpc/ptrace.h that prevents building at least the
SPU target version of gdb, since some ptrace opcodes are
not defined.

The problem seems to have originated in the merging of 32 and
64 bit versions of that file, the problem is that some opcodes
are only valid on 64 bit kernels, but are also used by 32 bit
programs, so they can't depends on the __powerpc64__ symbol.
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

I have tested PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS on umview.

I do not understand why historically these tags has been defined as
PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS instead of simply
PTRACE_[GS]ETREGS. The other "originality" is that the address must be
put into the "addr" field instead of the "data" field as stated in the
manual.
Signed-off-by: Nrenzo davoli <renzo@cs.unibo.it>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Move struct ptregs32 into asm-ppc64/ppc32.h
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>

- Add PTRACE_GET_DEBUGREG/PTRACE_SET_DEBUGREG. The definition is
  as follows:

/*
 * Get or set a debug register. The first 16 are DABR registers and the
 * second 16 are IABR registers.
 */
#define PTRACE_GET_DEBUGREG    25
#define PTRACE_SET_DEBUGREG    26

  DABR == data breakpoint and IABR = instruction breakpoint in IBM
  speak. We could split out the IABR into 2 more ptrace calls but I
  figured there was no need and 16 DABR registers should be more
  than enough (POWER4/POWER5 have one).

- Add 2 new SIGTRAP si_codes: TRAP_HWBKPT and TRAP_BRANCH. I couldnt
  find any standards on either of these so I copied what ia64 is
  doing. Again this might be better placed in
  include/asm-generic/siginfo.h
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

- Remove the PPC_REG* defines
- Wrap some more stuff with ifdef __KERNEL__
- Add missing PT_TRAP, PT_DAR, PT_DSISR defines
- Add PTRACE_GETEVRREGS/PTRACE_SETEVRREGS, even though we dont use it on
  ppc64 we dont want to allocate them for something else.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.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!