misc/sgi-xp: Replace in_interrupt() usage

The usage of in_interrupt() in xpc_partition_disengaged() is clearly
intended to avoid canceling the timeout timer when the function is invoked
from the timer callback.

While in_interrupt() is deprecated and ill defined as it does not provide
what the name suggests it catches the intended case.

Add an argument to xpc_partition_disengaged() which is true if called
from timer and otherwise false.
Use del_timer_sync() instead of del_singleshot_timer_sync() which is the
same thing.

Note: This does not prevent reentrancy into the function as the function
has no concurrency control and timer callback and regular task context
callers can happen concurrently on different CPUs or the timer can
interrupt the task context before it is able to cancel it.

While the only driver which is providing the arch_xpc_ops callbacks
(xpc_uv) seems not to have a reentrancy problem and the only negative
effect would be a double dev_info() entry in dmesg, the whole mechanism is
conceptually broken.

But that's not subject of this cleanup endeavour and left as an exercise to
the folks who might have interest to make that code fully correct.

[bigeasy: Add the argument, use del_timer_sync().]

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Cliff Whickman <cpw@sgi.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Steve Wahl <steve.wahl@hpe.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Russ Anderson <russ.anderson@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20201119103151.ppo45mj53ulbxjx4@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc/sgi-xp: remove SGI SN2 support

Note this also marks xp broken on ia64 now, as the UV support, which
was disable in generic kernels before actually never compiled due to
undefined uv_gpa_to_soc_phys_ram and uv_gpa_in_mmr_space symbols since
at least commit c2c9f1157414 ("x86: uv: update XPC to handle updated
BIOS interface").

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20190813072514.23299-11-hch@lst.de
Signed-off-by: Tony Luck <tony.luck@intel.com>

sgi-xpc: clean up numerous globals

Introduce xpc_arch_ops and eliminate numerous individual global definitions.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xpc: implement opencomplete messaging

sgi-xpc has a window of failure where an open message can be sent and a
subsequent data message can get lost. We have added a new message
(opencomplete) which closes that window.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xpc: prevent false heartbeat failures

The heartbeat timeout functionality in sgi-xpc is currently not trained to
the connection time. If a connection is made and the code is in the last
polling window prior to doing a timeout, the next polling window will see
the heartbeat as unchanged and initiate a no-heartbeat disconnect.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-gru: add support to the GRU driver for message queue interrupts

Add support to the GRU driver for message queue interrupts.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: fix writing past the end of kzalloc()'d space

A missing type cast results in writing way beyond the end of a kzalloc()'d
memory segment resulting in slab corruption. But it seems like the better
solution is to define ->recv_msg_slots as a 'void *' rather than a
'struct xpc_notify_mq_msg_uv *' and add the type cast.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: create activate and notify gru message queues

For UV add the code to create the activate and notify gru message queues.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

sgi-xp: setup the notify GRU message queue

Setup the notify GRU message queue that is used for sending user messages
on UV systems.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: setup the activate GRU message queue

Setup the activate GRU message queue that is used for partition activation
and channel connection on UV systems.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: cleanup naming of partition defines

Cleanup naming of partition defines.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: move xpc_check_remote_hb() to support both SN2 and UV

Move xpc_check_remote_hb() so it can support both SN2 and UV.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: add usage of GRU driver by xpc_remote_memcpy()

Add UV support to xpc_remote_memcpy(), which involves interfacing to the
GRU driver.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: enable building of XPC/XPNET on x86_64

Get XPC/XPNET to build on x86_64. Trying to modprobe them up on a non-UV
or sn2 system will result in a -ENODEV.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: add 'jiffies' to reserved page's timestamp name

Rename XPC's reserved page's timestamp member to reflect the units of time
involved.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: use standard bitops macros and functions

Change sgi-xp to use the standard bitops macros and functions instead of
trying to invent its own mechanism.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: eliminate '>>>' in comments

Comments in /drivers/misc/sgi-xp has been using '>>>' as a means to draw
attention to something that needs to be done or considered. To avoid
colliding with git rejects, '>>>' will now be replaced by '!!!' to
indicate something to do, and by '???' to indicate something to be
considered.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate remote copy buffer to sn2 only

Make the remote copy buffer an sn2 only item.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate allocation of XPC's msgqueues to sn2 only

Move the allocation of XPC's msgqueues to xpc_sn2.c.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: replace AMO_t typedef by struct amo

Replace the AMO_t typedef by a direct reference to 'struct amo'.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: separate chctl_flags from XPC's notify IRQ

Tie current IPI references to either XPC's notify IRQ or channel control
flags.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate additional sn2 specific code

Move additional sn2 specific code into xpc_sn2.c.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate activate IRQ's hardware specific components

Isolate architecture specific code related to XPC's activate IRQ.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: move xpc_allocate() into xpc_send()/xpc_send_notify()

Move xpc_allocate() functionality into xpc_send()/xpc_send_notify() so
xpc_allocate() no longer needs to be called by XPNET.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: base xpc_rsvd_page's timestamp on jiffies

Change XPC's reserved page timestamp to be based on jiffies.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate xpc_vars structure to sn2 only

Isolate the xpc_vars structure of XPC's reserved page to sn2 only.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: isolate xpc_vars_part structure to sn2 only

Isolate the xpc_vars_part structure of XPC's reserved page to sn2 only.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: prepare xpc_rsvd_page to work on either sn2 or uv hardware

Prepare XPC's reserved page header to work for either sn2 or uv.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: create a common xp_remote_memcpy() function

Create a common remote memcpy function that maps to what the hardware
booted supports.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sgi-xp: support runtime selection of xp_max_npartitions

Support runtime selection of the max number of partitions based on the
hardware being run on.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/sgi-xp: replace partid_t with a short

In preparation for supporting greater than 64 partitions replace partid_t by
short in drivers/misc/sgi-xp.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Acked-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/sgi-xp: clean up return values

Make XP return values more generic to XP and not so tied to XPC by changing
enum xpc_retval to xp_retval, along with changing return value prefixes from
xpc to xp. Also, cleanup a comment block that referenced some of these return
values as well as the handling of BTE related return values.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Acked-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[IA64] run drivers/misc/sgi-xp through scripts/checkpatch.pl

Addressed issues raised by scripts/checkpatch.pl. Removed unnecessary curly
braces. Eliminated uses of volatiles and use of kernel_thread() and daemonize().

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

[IA64] run some drivers/misc/sgi-xp through scripts/Lindent

Ran patches through scripts/Lindent (part 1).

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

[IA64] move XP and XPC to drivers/misc/sgi-xp

Move XPC and XPNET from arch/ia64/sn/kernel to drivers/misc/sgi-xp.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>