This shift instruction appears to be shifting in the wrong direction.
Without this change, my SparcStation-20MP hangs just after bringing up
the second CPU:

Entering SMP Mode...
Starting CPU 2 at f02b4e90
Brought up 2 CPUs
Total of 2 processors activated (99.52 BogoMIPS).
   *** stuck ***
Signed-off-by: NWill Simoneau <simoneau@ele.uri.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Three new IPIs were introduced by commit
ecbc42b7 ("sparc32, sun4m:
Implemented SMP IPIs support for SUN4M machines"), the
old handler was already prepared for IPIs but handled only
IRQ14 and IRQ13, this patch adds support for the new IPI at
IRQ12.

The IPI trap handler looks at the mask rather than the
pending IRQ/IPI, this bug may have masked the problem
above, introduced by the same commit.
Signed-off-by: NDaniel Hellstrom <daniel@gaisler.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDaniel Hellstrom <daniel@gaisler.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement the three IPIs (resched, single and cpu-mask) generation
and interrupt handler catch. The sun4m has 15 soft-IRQs and three
of them is used with this patch, the three IPIs was previously
implemented with the cross-call IRQ15 which does not work with
locking routines such as spinlocks because IRQ15 is NMI, it may
cause deadlock.

The IRQ trap handler code assumes (in the same spritit as the old
it seems) that hard interrupts will be generated until handled
(level), when a IRQ happens the IRQ pending register is checked
for pending soft-IRQs. When both hard and soft IRQ happens at the
same time only soft-IRQs are handled.

The old code implemented a soft-IRQ traphandler at IRQ14 which
called smp_reschedule_irq which in turn called set_need_resched.
It seems to be an old relic and is replaced with the interrupt
traphander exit code RESTORE_ALL, it calls schedule() when
appropriate.
Signed-off-by: NDaniel Hellstrom <daniel@gaisler.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements SMP IPIs on LEON using software generated
IRQs to signal between CPUs.

The IPI IRQ number is set by using the ipi_num property in the
device tree, or defaults to 13. LEON SMP systems should reserve
IRQ 13 (and IRQ 15) to Linux in order for the defaults to work.
Signed-off-by: NDaniel Hellstrom <daniel@gaisler.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDaniel Hellstrom <daniel@gaisler.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

We have to pass task_struct of previous process to function
schedule_tail(). Currently in ret_from_fork previous thread_info
is passed:

switch_to: mov %g6, %g3 /* previous thread_info in g6 */

ret_from_fork: call    schedule_tail
                mov    %g3, %o0 /* previous thread_info is passed */

void schedule_tail(struct task_struct *prev);
Signed-off-by: NTkhai Kirill <tkhai@yandex.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Support SMP for a Sparc-Leon multiprocessor system.
Add Leon specific SMP code to arch/sparc/kernel/leon_smp.c.
Signed-off-by: NKonrad Eisele <konrad@gaisler.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove __attribute__((weak)) from common code sys_pipe implemantation.
IA64, ALPHA, SUPERH (32bit) and SPARC (32bit) have own implemantations
with the same name. Just rename them.
For sys_pipe2 there is no architecture specific implementation.

Cc: Richard Henderson <rth@twiddle.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While doing some easy cleanups on the sparc code I noticed that the
CONFIG_SUN4 code seems to be worse than the rest - there were some
"I don't know how it should work, but the current code definitely cannot
work." places.

And while I have seen people running Linux on machines like a
SPARCstation 5 a few years ago I don't recall having seen sun4
machines, even less ones running Linux.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sparc64 exports openprom.h to userspace so let sparc follow
the example.
As openprom.h pulled in another not-for-export vaddrs.h header
file it required a few changes to fix the build.

The definition af VMALLOC_* were moved to pgtable as this is
where sparc64 has them.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

This patch contains the following possible cleanups:
- make the following needlessly global code static:
  - apc.c: apc_swift_idle()
  - ebus.c: ebus_blacklist_irq()
  - ebus.c: fill_ebus_child()
  - ebus.c: fill_ebus_device()
  - entry.S: syscall_is_too_hard
  - etra: tsetup_sun4c_stackchk
  - head.S: cputyp
  - head.S: prom_vector_p
  - idprom.c: Sun_Machines[]
  - ioport.c: _sparc_find_resource()
  - ioport.c: create_proc_read_entry()
  - irq.c: struct sparc_irq[]
  - rtrap.S: sun4c_rett_stackchk
  - setup.c: prom_sync_me()
  - setup.c: boot_flags
  - sun4c_irq.c: sun4c_sbint_to_irq()
  - sun4d_irq.c: sbus_tid[]
  - sun4d_irq.c: struct sbus_actions
  - sun4d_irq.c: sun4d_sbint_to_irq()
  - sun4m_irq.c: sun4m_sbint_to_irq()
  - sun4m_irq.c: sun4m_get_irqmask()
  - sun4m_irq.c: sun4m_timers
  - sun4m_smp.c: smp4m_cross_call()
  - sun4m_smp.c: smp4m_blackbox_id()
  - sun4m_smp.c: smp4m_blackbox_current()
  - time.c: sp_clock_typ
  - time.c: sbus_time_init()
  - traps.c: instruction_dump()
  - wof.S: spwin_sun4c_stackchk
  - wuf.S: sun4c_fwin_stackchk
- #if 0 the following unused code:
  - process.c: sparc_backtrace_lock
  - process.c: __show_backtrace()
  - process.c: show_backtrace()
  - process.c: smp_show_backtrace_all_cpus()
- remove the following unused code:
  - entry.S: __handle_exception
  - smp.c: smp_num_cpus
  - smp.c: smp_activated
  - smp.c: __cpu_number_map[]
  - smp.c: __cpu_logical_map[]
  - smp.c: bitops_spinlock
  - traps.c: trap_curbuf
  - traps.c: trapbuf[]
  - traps.c: linux_smp_still_initting
  - traps.c: thiscpus_tbr
  - traps.c: thiscpus_mid
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal.  It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.

Problem is, this doesn't work.

The idea was that we should do the syscall restart business first, so
that the debugger captures that state.  Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.

The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.

In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb.  gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop().  The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal.  But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.

Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:

1) Report a "in syscall" software bit in regs->{tstate,psr}.
   It is set early on in trap entry to a system call and is fully
   visible to the debugger via ptrace() and regsets.

2) Test this bit right before doing a syscall restart.  We have
   to do a final recheck right after get_signal_to_deliver() in
   case the debugger cleared the bit during ptrace_stop().

3) Clear the bit in trap return so we don't accidently try to set
   that bit in the real register.

As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.

M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook.  It needs to be fixed in the same exact
way as sparc.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current limitations:

1) On SMP single stepping has some fundamental issues,
   shared with other sw single-step architectures such
   as mips and arm.

2) On 32-bit sparc we don't support SMP kgdb yet.  That
   requires some reworking of the IPI mechanisms and
   infrastructure on that platform.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The following cleanups are now possible:
- arch/sparc/kernel/entry.S:ret_sys_call no longer has to be global
- arch/sparc/kernel/signal.c:sys_sigpause() can be removed
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As per Documentation/feature-removal-schedule.txt
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__ndelay and __udelay have not been delayung >= specified time.
The problem with __ndelay has been tacked down to the rounding of the
multiplier constant. By changing this, delays > app 18us are correctly
calculated.
The problem with __udelay has also been tracked down to rounding issues.
Changing the multiplier constant (to match that used in sparc64) corrects
for large delays and adding in a rounding constant corrects for trunctaion
errors in the claculations.
Many short delays will return without looping. This is not an error as there
is the fixed delay of doing all the maths to calculate the loop count.
Signed-off-by: NMark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When I added the entries for the robust futex syscall entries, I
forgot to bump NR_SYSCALLS.  The current situation is error-prone
because NR_SYSCALLS lives in entry.S where the system call limit
checks are enforced.  Move the definition to asm/unistd.h in order to
make this mistake much more difficult to make.

And wire up sys_migrate_pages since the powerpc folks implemented the
compat wrapper for us.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Also, the Solaris syscall table is sized differrently,
and does not go beyond entry 255, so trim off the excess
entries.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To let new syscalls through.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.

The sparc signal handling code is quite a mess and I should
clean it up some day.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename all includes to use asm-offsets.h to match generic name
Signed-off-by: NSam Ravnborg <sam@ravnborg.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!