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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Robin Holt <holt@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Not a single line of actual code in the function was really
fundamentally correct.
Problems ranged from lack of proper range checking, to removing the last
character written (which admittedly is usually '\n'), to not accepting
hex numbers even though the 'show' routine would show the data in that
format.
This tries to do better.
Acked-by: Michael Buesch <mb@bu3sch.de>
Tested-and-acked-by: Jack Steiner <steiner@sgi.com>
Cc: stable@kernel.org
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Michael Gilbert <michael.s.gilbert@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code
But leave TTM code alone, something is fishy there with global vm_ops
being used.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The allocation may fail.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the copyright statements in a couple of GRU files. No functional
changes are being made.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Delete references to the SGI GRU GSH hardware resources. These GRU
resources have been deleted from the hardware. (These resources have
never benn used, anyway).
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minor fixes to the SGI GRU grudump facility:
- fix address where user data is written
- add gru number to data passed to user
- indicate if context is locked
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix potential SGI GRU bug that could cause a use-after-free. If one
thread in a task is flushing the GRU and another thread destroys the GRU
context, there is the potential to access a table after it has been freed.
Copy the gms pointer to a local variable before unlocking the gts table.
Note that no refcnt is needed for the gms - the reference is held
indirectly by the task's mm_struct.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a user request to specify the gru instruction slice parameter for user
contexts.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the user GRU request for specifying the "task_slice" option to use
a generic infrastructure that can be expanded in the future to include
additional context options. No new capabilities are added with this
patch.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup of GRU inline functions to eliminate unnecessary inline code.
Update function descriptions.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Delete the user request for fetching the status of a GRU chiplet. This
request has been made obsolete by other changes. Note: this is not a
change to a user API - there are no compatibility issues with this change.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Collect GRU statistics for each user GRU context. Statistics are kept for
TLB misses & content resource contention. Add user request for retrieving
the statistics.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for interrupts generated by GRU instruction completion.
Previously, the only interrupts were for TLB misses. The hardware also
supports interrupts on instruction completion. This will be supported for
instructions issued by the kernel.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check whether the gru state being loaded into a gru is from a new context
or a previously unloaded context. If new, simply zero out the hardware
context; if unloaded and valid, reload the old state.
This change is primarily for reloading kernel contexts where the previous
is not required to be saved.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Support alocation of GRU contexts that contain zero DSR or CBR resources.
Some instructions do not require DSR resources. Contexts without CBR
resources are useful for diagnostics.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove "static" from the functions for loading/unloading GRU contexts.
These functions will be called from other GRU files. Fix bug in unlocking
gru context.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the interface to gru_alloc_gts() so that it can be used to allocate
GRU contexts for kernel threads. Kernel threads do not have vdata
structures for the GRU contexts. The GRU resource count are now passed
explicitly instead of inside the vdata structure.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for dumpping the state of an entire GRU chiplet.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug fixes for GRU exception handling. Additional fields from the CBR must
be returned to the user to allow the user to correctly diagnose GRU
exceptions.
Handle endcase in TFH TLB miss handling. Verify that TFH actually
indicates a pending exception.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Callers of alloc_pages_node() can optionally specify -1 as a node to mean
"allocate from the current node". However, a number of the callers in
fast paths know for a fact their node is valid. To avoid a comparison and
branch, this patch adds alloc_pages_exact_node() that only checks the nid
with VM_BUG_ON(). Callers that know their node is valid are then
converted.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org> [for the SLOB NUMA bits]
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For an upcoming distro release, we need to have the xp kernel module
loadable even when not on UV equipment. The xpc module will not load.
This will allow one set of modules dependent upon xp to work on either UV
or non-UV equipment.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add multiple pagesize support to the GRU driver.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix bugs related to module unload of the GRU driver.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add macro for scanning all active GRU chiplets. Maximum chiplet id is
saved during GRU initialization.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Restructure the GRU vtop functions in preparation for future changes.
This patch simply moves code around & does not change the algorithm.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes bugs related to ASID (context id) management in the GRU
driver. These changes are all internal to the SGI GRU driver and have no
effect on the base kernel.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for a user to explicitly unload a GRU context.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add statistics to the GRU context management functions.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the GRU instructions that manage contexts from inline functions to
out-of-line functions. This simplifies adding statistics & error checking
to these functions.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the ia64 build error that occurs in the linux-next tree by introducing
an ia64 version of uv.h.
Additionally, clean up the usage of is_uv_system().
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix more build-failure fallout from the UV cleanup - the UV drivers
were not updated to include <asm/uv/uv.h>.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Eliminate compile error when compiling without CONFIG_HUGETLB_PAGE.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
If xpc.ko and gru.ko are both statically linked into the kernel, then
xpc_init() can get called before gru_init() and make a call to one of the
gru's exported functions before the gru has initialized itself. The end
result is a NULL dereference.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable -D DEBUG in the GRU Makefile if CONFIG_SGI_GRU_DEBUG is selected.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: fix double entry creation in /proc
There is a collision between two UV functions:
both uv_ptc_init() and gru_proc_init() try to make /proc/sgi_uv
So move it's creation to a single place: uv_system_init()
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Julia Lawall <julia@diku.dk>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you are on ia64 and you modprobe xpc then modprobe -r xpc, you
immediately get a panic. xpc depends on xp which depends on gru for a
symbol. That symbol is only used when we are running on UV hardware.
Currently, the GRU driver detects we are not on UV hardware and does no
initializing. It does not do the same check when unloading. As a result,
the gru driver attempts to tear down stuff that was not setup.
This is a simple two-line workaround to get us through this release. Once
2.6.28 is opened, we need to rework the symbols that xp is depending on
from gru so the gru driver can properly fail to load when hardware is not
available.
Signed-off-by: Robin Holt <holt@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>
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: Jack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the GRU driver makefile
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file contains the functions for handlinf GRU TLB flushing, This
includes functions to handle the MMUOPS callouts.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file externalizes some GRU state & statistics to the user using the
/proc file system.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file contains functions for handling services provided to other
kernel modules that use the GRU.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file contains the functions that manage GRU page faults and
exceptions.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file contains the functions for initializing the driver, handling
file & vma operations and for processing IOCTL requests from the user.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch contains the header file used to export GRU services to other
kernel drivers such as XPMEM or XPNET.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch contains header files internal to the GRU driver.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchs contains macros & inline functions used to issue instructions
to the GRU.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series of patches adds a driver for the SGI UV GRU. The driver is
still in development but it currently compiles for both x86_64 & IA64.
All simple regression tests pass on IA64. Although features remain to be
added, I'd like to start the process of getting the driver into the
kernel. Additional kernel drivers will depend on services provide by the
GRU driver.
The GRU is a hardware resource located in the system chipset. The GRU
contains memory that is mmaped into the user address space. This memory
is used to communicate with the GRU to perform functions such as
load/store, scatter/gather, bcopy, AMOs, etc. The GRU is directly
accessed by user instructions using user virtual addresses. GRU
instructions (ex., bcopy) use user virtual addresses for operands.
The GRU contains a large TLB that is functionally very similar to
processor TLBs. Because the external contains a TLB with user virtual
address, it requires callouts from the core VM system when certain types
of changes are made to the process page tables. There are several MMUOPS
patches currently being discussed but none has been accepted into the
kernel. The GRU driver is built using version V18 from Andrea Arcangeli.
This patch:
Contains the definitions of the hardware GRU data structures that are used
by the driver to manage the GRU.
[akpm@linux-foundation;org: export hpage_shift]
Signed-off-by: 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>
