Use no-op messages in place of cross-partition interrupts when nacking a
put message in the GRU.  This allows us to remove MMR's as a destination
from the GRU driver.
Tested-by: NJohn Estabrook <estabrook@sgi.com>
Tested-by: NGary Kroening <gfk@sgi.com>
Tested-by: NNathan Zimmer <nzimmer@sgi.com>
Signed-off-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160429215406.012228480@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

dw was only assigned some value and was never reused.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Acked-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

gru_alloc_gts() can fail and it can return ERR_PTR(errvalue). We should
not dereference it if it has returned error. And incase it has returned
error then wait for some time and try again.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Acked-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The functions gru_get_cb_exception_detail_str() and gru_abort() were
only called locally from that file. We can make them static.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Acked-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We will need this to avoid build failures pending a future implicit
module.h presence cleanup.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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

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>

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>

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>

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>

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>

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 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 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>

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>

The allocation may fail.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-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 smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix bug in automatic retry of GRU instruction failures.  CBR substatus
(message queue failure) was being checked incorrectly.
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 user function to explicitly unload GRU kernel contexts from the GRU.
Only contexts that are not in-use will be unloaded.

This function is primarily for testing.  It is not expected that this will
be used in normal production systems.
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 two problems related to GRU instruction failures.  Cache coherency is
not maintained for CBEs except when loading or unloading contexts.  When
reading a CBE to extract error information, the CBE must first be flushed
from the cache.

The function that reads kerrnel CBEs was reading the wrong CBE.
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 GRU driver to the latest version of the GRU spec. This consists
of minor updates:
	- changes & additions to error status bits
	- new restriction on handling of TLB misses while in FMM mode
	- new field (not used by software) in TFH
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 kernel self tests that can be optionally executed on GRU
initialization.  This is primarily for testing.

Eliminate the BUG statements on failure and return bad status.  Add ioctl
interface to execute the tests on demand.
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 asynchronous GRU instructions.  Currently, asynchronous
instructions are supported only for GRU instructions issued by the kernel.

[akpm@linux-foundation.org: build fix]
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 endcase in handling GRU message queue failures due to NACKs of PUT
requests.  Must ensure that the "present" bits are cleared before
resending the message.
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 way GRU resources are assigned for kernel threads.  GRU
contexts for kernel threads are now allocated on demand and can be stolen
by user processes when idle.  This allows MPI jobs to use ALL of the GRU
resources when the kernel is not using them.
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 interface to cch_allocate so that it can be used to allocate
GRU contexts for kernel threads.  Kernel threads use the GRU in unmapped
mode and do not require ASIDs for the GRU TLB.
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 multiple pagesize support to 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>

Fix bugs related to module unload 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>

Add support to the GRU driver for message queue interrupts.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NDean Nelson <dcn@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Improvements to GRU debug messages & statistics.
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>

Misc trivial GRU drivers fixes:
	- fix long lines
	- eliminate extra whitespace
	- eliminate compiler warning
	- better validation of invalidate user parameters
	- bug fix for GRU TLB flush (not the cpu TLB flush)

These changes are all internal to the SGI GRU driver and have no effect
on the base kernel.
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>

A few minor updates for the GRU driver.
	- documentation changes found in code reviews
	- changes to #ifdefs to make them recognized by "unifdef"
	  (used in simulator testing)
	- change GRU context load/unload to prefetch data

[akpm@linux-foundation.org: fix typo in comment]
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>

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

An extract of the semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@haskernel@
@@

#include <linux/kernel.h>

@depends on haskernel@
expression n,d;
@@

(
- (n + d - 1) / d
+ DIV_ROUND_UP(n,d)
|
- (n + (d - 1)) / d
+ DIV_ROUND_UP(n,d)
)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP((n),d)
+ DIV_ROUND_UP(n,d)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP(n,(d))
+ DIV_ROUND_UP(n,d)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes problems identified in a code review:
	- add comment with high level dscription of the GRU
	- prepend "gru_" to all global names
	- delete unused function
	- couple of trivial bug fixes

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NJack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This file contains functions for handling services provided to other
kernel modules that use the GRU.
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>