GRU Message queue instructions are used to deliver messages to other SSIs
within the numalink domain.  In most cases, a single GRU mesq instruction
will deliver both the message AND an interrupt to notify the other SSI
that a messsage is present.  In some cases, however, the interrupt must be
sent explicitly.

To improve resilency, the GRU driver should send these explicit interrupts
using the GRU to write the remote chipset register.  Current code sends
the interrupt using a cpu instruction to write the chipset register.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Create a function to generate the value that is written to the UV hub MMR
to cause an IPI interrupt to be sent.  The function will be used in the
GRU message queue error recovery code that sends IPIs to nodes in remote
partitions.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the version number of the GRU driver.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the TLB dropin statistics kept for each GRU context.  Count TLB
dropins separate from the misses - some misses do not result in a TLB
dropin.  Some of the diagnostics need both counts.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a race where an interrupt could be received for a GRU context that has
been deallocated.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for hugepages. Easier than I originally thought.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a bug in the assignment of GRU contexts used for kernel functions.  If
a sleep occurs on the wait for a semaphore, the thread could switch cpus
and allocate resources on the wrong blade.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a few new definitions for chipset MMR field names.  This matches rev
0.7 of the hardware spec.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simplify the code that checks for correct assignment of GRU contexts to
users.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove a stray local_irq_enable() in the GRU TLB dropin code.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use symbol names instead of numbers for error return values for the vtop
functions.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a GRU driver bug converting a CBR address to the context that contains
the CBR.  The conversion is rarely done so performance does not matter.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add anticipatory TLB dropins for GRU TLB misses that occur on BCOPY
instructions that copy large amounts of data.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Explicitly set GRU instructions to "ACTIVE".  This eliminates the need for
barriers that would have been necessary to prevent reading the instruction
"status" field before the GRU had actually started the instruction.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add additional GRU statistics & debug messages.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the GRU irq allocate/free functions to use the latest upstream
infrastructure.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix several bugs related to prefetch, ordering & speculation:

	- GRU cch_allocate() instruction causes cacheable memory
	  to be created. Add a barriers to prevent speculation
	  from prefetching data before it exists.
	- Add memory barriers before cache-flush instructions to ensure
	  that previously stored data is included in the line flushed to memory.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix bug caused by failure to allocate a GRU gts structure.  The old code
failed to handle the case where the vma was invalid.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Improve existing driver self-tests.  Add a new debugging test to the SGI
GRU driver for verifying the global GRU copy function.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a debug option to the SGI GRU driver for flushing GRU cache lines from
memory.  In theory this is not needed but it is useful for debugging.
This has no use by end users.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Under some conditions, mmu_notifier_register() will fail to register a
mmu_notifier.  Fix the GRU driver to correctly handle these failures.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Increase the maximum address supported by the SGI GRU driver to a full 64
bits.  Note that GRU addresses are not always the same as socket virtual
addresses.  Sockets may not necessarily support the full 64 bits.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Improve error messages for malfunctioning GRUs.  Identify the type of
instruction that is failing.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix bug in module unload.  Previous code was not correctly deleting the
files in /proc.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch builds on the infrastructure introduced in the patches that
allow user specification of GRU blades & chiplets for context allocation.

This patch simplifies the algorithms for migrating GRU contexts between
blades.

No new functionality is introduced.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support to the GRU driver to allow users to specify the blade &
chiplet for allocation of GRU contexts.  Add new statistics for context
loading/unloading/retargeting.  Also deleted a few GRU stats that were no
longer being unused.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add table & user request infrastructure that is needed to allow users to
specify the blade and chiplet for allocation of GRU contexts.  Use of this
information is in a subsequent patch.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Do not use alloc_pages_exact_node() to allocate GRU tables.  If a blade
has no local memory, nid will be -1.  Use alloc_pages_node() instead.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

TLB dropins require updates to the CBR instruction istatus field.  This is
needed to resolve race conditions in the chip.

The code currently uses the user address of the CBR.  This works but opens
up additional endcases related to stealing of contexts and accessing the
CBR from tasks that do not have access to the user address space.  (Some
of this non-user task access is debug code that is not currently being
pushed to the community).

User CBRs are also directly accessible using the kernel mapping of the
CBR.  Change the TLB dropin code to use the the kernel mapping of the CBR.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add comments from previous code reviews.  The comments help explain some
of the more esoteric aspects of the driver.

Move a free() to the other side of an unlock.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change the GRU initialization code to initialize based on blade topology
instead of node topology.  The result is the same but blade-based
initialization is cleaner.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, the UV xpc code is passing nid to the gru_create_message_queue
instead of nasid as it expects.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This was a difficult bug to trip.  XPC was in the middle of sending an
acknowledgement for a received message.

In xpc_received_payload_uv():
.
        ret = xpc_send_gru_msg(ch->sn.uv.cached_notify_gru_mq_desc, msg,
                               sizeof(struct xpc_notify_mq_msghdr_uv));
        if (ret != xpSuccess)
                XPC_DEACTIVATE_PARTITION(&xpc_partitions[ch->partid], ret);

        msg->hdr.msg_slot_number += ch->remote_nentries;

at the point in xpc_send_gru_msg() where the hardware has dispatched the
acknowledgement, the remote side is able to reuse the message structure
and send a message with a different slot number.  This problem is made
worse by interrupts.

The adjustment of msg_slot_number and the BUG_ON in
xpc_handle_notify_mq_msg_uv() which verifies the msg_slot_number is
consistent are only used for debug purposes.  Since a fix for this that
preserves the debug functionality would either have to infringe upon the
payload or allocate another structure just for debug, I decided to remove
it entirely.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many times while the initial connection is being made, the contacted
partition will send back both the ACTIVATING and the ACTIVE
remote_act_state changes in very close succescion.  The 1/4 second delay
in the make first contact loop is large enough to nearly always miss the
ACTIVATING state change.

Since either state indicates the remote partition has acknowledged our
state change, accept either.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Under heavy load conditions, our set of xpc messages may become exhausted.
 The code handles this correctly with the exception of the management code
which hits a NULL pointer dereference.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The UV BIOS has moved the location of some of their pointers to the
"partition reserved page" from memory into a uv hub MMR.  The GRU does not
support bcopy operations from MMR space so we need to special case the MMR
addresses using VLOAD operations.

Additionally, the BIOS call for registering a message queue watchlist has
removed the 'blade' value and eliminated the structure that was being
passed in.  This is also reflected in this patch.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The BIOS has decided to store a pointer to the partition reserved page in
a scratch MMR.  The GRU is only able to read an MMR using a vload
instruction.  The gru_read_gpa() function will implemented.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a mechanism for determining if a global physical address is
pointing to a UV hub MMR.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide an SGI SN2/UV agnositic method for converting a global physical
address into a socket physical address.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The UV BIOS has been updated to implement some of our interface
functionality differently than originally expected.  These patches update
the kernel to the bios implementation and include a few minor bug fixes
which prevent us from doing significant testing on real hardware.

This patch:

For SGI UV systems, translate from a global physical address back to a
socket physical address.  This does nothing to ensure the socket physical
address is actually addressable by the kernel.  That is the responsibility
of the user of the function.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>