ARC: Allow SMP kernel to build/boot on UP-only infrastructure

In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.

* Remove the dependence on simulation SMP extension to enable quick
  build/test iterations of SMP kernel.

* In absence of platform SMP registration, prevent the NULL smp feature
  name from borkign the system

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
powerpc: Fix sys_call_table declaration to enable syscall tracing

Declaring sys_call_table as a pointer causes the compiler to generate
the wrong lookup code in arch_syscall_addr().

     <arch_syscall_addr>:
        lis     r9,-16384
        rlwinm  r3,r3,2,0,29
  -     lwz     r11,30640(r9)
  -     lwzx    r3,r11,r3
  +     addi    r9,r9,30640
  +     lwzx    r3,r9,r3
        blr

The actual sys_call_table symbol, declared in assembler, is an
array. If we lie about that to the compiler we get the wrong code
generated, as above.

This definition seems only to be used by the syscall tracing code in
kernel/trace/trace_syscalls.c. With this patch I can successfully use
the syscall tracepoints:

  bash-3815  [002] ....   333.239082: sys_write -> 0x2
  bash-3815  [002] ....   333.239087: sys_dup2(oldfd: a, newfd: 1)
  bash-3815  [002] ....   333.239088: sys_dup2 -> 0x1
  bash-3815  [002] ....   333.239092: sys_fcntl(fd: a, cmd: 1, arg: 0)
  bash-3815  [002] ....   333.239093: sys_fcntl -> 0x1
  bash-3815  [002] ....   333.239094: sys_close(fd: a)
  bash-3815  [002] ....   333.239094: sys_close -> 0x0

Signed-off-by: Romeo Cane <romeo.cane.ext@coriant.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/book3s: Don't clear MSR_RI in hmi handler.

In HMI interrupt handler we don't touch SRR0/SRR1, instead we touch
HSRR0/HSRR1. Hence we don't need to clear MSR_RI bit.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Fallback to old HMI handling behavior for old firmware

Recently we moved HMI handling into Linux kernel instead of taking
HMI directly in OPAL. This new change is dependent on new OPAL call
for HMI recovery which was introduced in newer firmware. While this new
change works fine with latest OPAL firmware, we broke the HMI handling
if we run newer kernel on old OPAL firmware that results in system hang.

This patch fixes this issue by falling back to old HMI behavior on older
OPAL firmware.

This patch introduces a check for opal token OPAL_HANDLE_HMI to see
if we are running on newer firmware or old firmware. On newer firmware
this check would return OPAL_TOKEN_PRESENT, otherwise we are running on
old firmware and fallback to old HMI behavior.

Old firmware: POWER8 System Firmware Release as of today <= SV810_087
Action: Let OPAL handle HMIs

Newer firmware: in development/yet to be released.
Action: Let Linux host handle HMIs.

This patch depends on opal check token patch posted at ppc-devel
https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/120224.html

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: Minor comment and printk rewording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/numa: check error return from proc_create

proc_create can fail, we should check the return value and pass up the
failure.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/numa: Add ability to disable and debug topology updates

We have hit a few customer issues with the topology update code (VPHN
and PRRN). It would be nice to be able to debug the notifications coming
from the hypervisor in both cases to the LPAR, as well as to disable
responding to the notifications at boot-time, to narrow down the source
of the problems. Add a basic level of such functionality, similar to the
numa= command-line parameter. We already have a toggle in
/proc/powerpc/topology_updates that allows run-time enabling/disabling,
so the updates can be started at run-time if desired. But the bugs we've
run into have occured during boot or very shortly after coming to login,
and have resulted in a broken NUMA topology.

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ARC: [arcfpga] consolidate machine description, DT

* AA4/ML509 have same machine descriptions
* Rename simulation machine description

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: [plat*] move code out of .init_machine into common

All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: [arcfpga] Remove more dead code

specifically after switching to generic early arc uart, whole bunch of
code is no longer needed

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: [arcfpga] Get rid of ARC_BOARD_ANGEL4 and ARC_BOARD_ML509

Commit c00bfd974fb0 ("ARC: [arcfpga] Get rid of legacy BVCI latency unit
support") removed the Kconfig symbol ARC_HAS_BVCI_LAT_UNIT. And that
symbol's entry was the only place were the symbols ARC_BOARD_ANGEL4 and
ARC_BOARD_ML509 were used. So ARC_BOARD_ANGEL4 and ARC_BOARD_ML509 can
be removed too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: [nsimosci] Allow "headless" models to boot

There are certain test configuration of virtual platform which don't
have any real console device (uart/pgu). So add tty0 as a fallback console
device to allow system to boot and be accessible via telnet

Otherwise with ttyS0 as only console, but 8250 disabled in kernel build,
init chokes.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org> #3.10, 3.12, 3.14, 3.16
ARC: rename kconfig option for unaligned emulation

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: Update comments about uncached address space

Suggested-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: RIP @running_on_hw

* No active users of this flag anymore

* flag itself was no longer usable with new simualtor which acts just like
  hardware, not providing the special chip-id = 0xffff which good old
  ISS used to do.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: remove gcc mpy heuristics

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: refactoring: reduce the scope of some local vars

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: BUG() dumps stack after @msg (@msg now same as in generic BUG))

ARC specific version (doesn't panic) still makes sense so that generic
code calling BUG doesn't panic and helps debugging more

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: Remove unneeded Kconfig entry NO_DMA

Architectures only need a Kconfig entry for NO_DMA if it is possible
that its value will be 'y'. For arc its value will always be 'n', making
it pointless. Remove it.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: Update order of registers in KGDB to match GDB 7.5

Order of registers has changed in GDB moving from 6.8 to 7.5. This patch
updates KGDB to work properly with GDB 7.5, though makes it incompatible
with 6.8.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org> #3.10, 3.12, 3.14, 3.16
ARC: remove extraneous __KERNEL__ guards

Verified by doing make headers_install as none of these files are
exported to userspace