text	   data	    bss	    dec	    hex	filename
6309351	3578714	 696320	10584385	 a18141	vmlinux
6308391	3578714	 696320	10583425	 a17d81	vmlinux

Almost 1KiB of code reduction.

v2: More s/INTEL_INFO()->gen/INTEL_GEN()/ and IS_GENx() conversions

   text	   data	    bss	    dec	    hex	filename
6304579	3578778	 696320	10579677	 a16edd	vmlinux
6303427	3578778	 696320	10578525	 a16a5d	vmlinux

Now over 1KiB!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462545621-30125-3-git-send-email-chris@chris-wilson.co.uk

Allowing register copies where the source and destination are both
whitelisted should be safe, and is useful.  For example, Mesa uses
this to load the command streamer math registers with data from the
pipeline statistics counters.

v2: Reject writes to OACONTROL (and reads as well :(
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> # v1
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1462521014-13595-1-git-send-email-chris@chris-wilson.co.uk

If the command parser is not active, then it is appropriate to report it
as operating at version 0 as no higher mode is supported. This greatly
simplifies userspace querying for the command parser as we then do not
need to second guess when it will be active (a mixture of module
parameters and generational support, which may change over time).

v2: s/comand/command/ misspelling in comment
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1462368336-21230-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1457335830-30923-6-git-send-email-jordan.l.justen@intel.com

This is needed for the Mesa Vulkan driver on Haswell.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1457335830-30923-5-git-send-email-jordan.l.justen@intel.com

Now that we can whitelist registers only on Haswell, move HSW_SCRATCH1
and HSW_ROW_CHICKEN3 into a separate Haswell only table.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Cc: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1457335830-30923-4-git-send-email-jordan.l.justen@intel.com

For Haswell, we will want another table of registers while retaining
the large common table of whitelisted registers shared by all gen7
devices.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
[danvet: Pipe patch through sed -e 's/\<ring\>/engine/g' to make it
apply.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is needed for the Mesa Vulkan driver on Haswell.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Cc: Kristian Høgsberg <krh@bitplanet.net>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1457335830-30923-2-git-send-email-jordan.l.justen@intel.com

@@
identifier func;
@@
func(..., struct intel_engine_cs *
- ring
+ engine
, ...)
{
<...
- ring
+ engine
...>
}
@@
identifier func;
type T;
@@
T func(..., struct intel_engine_cs *
- ring
+ engine
, ...);
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Make I915_READ and I915_WRITE more type safe by wrapping the register
offset in a struct. This should eliminate most of the fumbles we've had
with misplaced parens.

This only takes care of normal mmio registers. We could extend the idea
to other register types and define each with its own struct. That way
you wouldn't be able to accidentally pass the wrong thing to a specific
register access function.

The gpio_reg setup is probably the ugliest thing left. But I figure I'd
just leave it for now, and wait for some divine inspiration to strike
before making it nice.

As for the generated code, it's actually a bit better sometimes. Eg.
looking at i915_irq_handler(), we can see the following change:
  lea    0x70024(%rdx,%rax,1),%r9d
  mov    $0x1,%edx
- movslq %r9d,%r9
- mov    %r9,%rsi
- mov    %r9,-0x58(%rbp)
- callq  *0xd8(%rbx)
+ mov    %r9d,%esi
+ mov    %r9d,-0x48(%rbp)
 callq  *0xd8(%rbx)

So previously gcc thought the register offset might be signed and
decided to sign extend it, just in case. The rest appears to be
mostly just minor shuffling of instructions.

v2: i915_mmio_reg_{offset,equal,valid}() helpers added
    s/_REG/_MMIO/ in the register defines
    mo more switch statements left to worry about
    ring_emit stuff got sorted in a prep patch
    cmd parser, lrc context and w/a batch buildup also in prep patch
    vgpu stuff cleaned up and moved to a prep patch
    all other unrelated changes split out
v3: Rebased due to BXT DSI/BLC, MOCS, etc.
v4: Rebased due to churn, s/i915_mmio_reg_t/i915_reg_t/
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1447853606-2751-1-git-send-email-ville.syrjala@linux.intel.com

Add defines for the upper halves of the registers used by the cmd
parser. Getting rid of the arithmetic with the register offset
will help in making registers type safe.

v2: s/_HI/_UDW/ (Chris)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1446839080-18732-1-git-send-email-ville.syrjala@linux.intel.com

This is required to support glDispatchComputeIndirect for gen7.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NKristian Høgsberg <krh@bitplanet.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fixes regression from
commit f1afe24f
Author: Arun Siluvery <arun.siluvery@linux.intel.com>
Date:   Tue Aug 4 16:22:20 2015 +0100

    drm/i915: Change SRM, LRM instructions to use correct length

which forgot to account for the length bias when declaring the fixed
length.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91844Reported-by: NAndreas Reis <andreas.reis@gmail.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was forgotten in

commit d351f6d9
Author: Francisco Jerez <currojerez@riseup.net>
Date:   Fri May 29 16:44:15 2015 +0300

    drm/i915: Add SCRATCH1 and ROW_CHICKEN3 to the register whitelist.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

MI_STORE_REGISTER_MEM, MI_LOAD_REGISTER_MEM instructions are not really
variable length instructions unlike MI_LOAD_REGISTER_IMM where it expects
(reg, addr) pairs so use fixed length for these instructions.

v2: rebase

Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Appease checkpatch as Mika spotted in i915_reg.h - it seems
terminally unhappy about i915_cmd_parser.c so that would be a separate
patch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As we may like to use a bisection search on the tables in future, we
need them to be ordered. For convenience we expect the compiled tables
to be order and check on initialisation. However, the validator used the
wrong iterators failed to spot the misordered MI tables and instead
walked off into the unknown (as spotted by kasan).
Signed-off-by: NHanno Boeck <hanno@hboeck.de>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Again hand-assemble patch ...]
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

In the future, we may want to speed up command/register searching using
a bisection and so we require them to be in ascending order respectively
by command value or register address. However, this was not true for one
pair in the MI table; make it so.
Signed-off-by: NHanno Boeck <hanno@hboeck.de>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Hand-assemble patch from raw patch from Hanno and commit message from Chris.]
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after PIPE_CONTROL
instruction but there is a slight complication as this is applied in WA batch
where the values are only initialized once.
Dave identified an issue with the current implementation where the register value
is read once at the beginning and it is reused; this patch corrects this by saving
the register value to memory, update register with the bit of our interest and
restore it back with original value.

This implementation uses MI_LOAD_REGISTER_MEM which is currently only used
by command parser and was using a default length of 0. This is now updated
with correct length and moved to appropriate place.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only bit 27 of SCRATCH1 and bit 6 of ROW_CHICKEN3 are allowed to be
set because of security-sensitive bits we don't want userspace to mess
with.  On HSW hardware the whitelisted bits control whether atomic
read-modify-write operations are performed on L3 or on GTI, and when
set to L3 (which can be 10x-30x better performing than on GTI,
depending on the application) require great care to avoid a system
hang, so we currently program them to be handled on GTI by default.

Beignet can immediately start taking advantage of this change to
enable L3 atomics.  Mesa should eventually switch to L3 atomics too,
but a number of non-trivial changes are still required so it will
continue using GTI atomics for now.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

In some cases it might be unnecessary or dangerous to give userspace
the right to write arbitrary values to some register, even though it
might be desirable to give it control of some of its bits.  This patch
extends the register whitelist entries to contain a mask/value pair in
addition to the register offset.  For registers with non-zero mask,
any LRM writes and LRI writes where the bits of the immediate given by
the mask don't match the specified value will be rejected.

This will be used in my next patch to grant userspace partial write
access to some sensitive registers.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Until now the software command checker assumed that commands could
read or write at most a single register per packet.  This is not
necessarily the case, MI_LOAD_REGISTER_IMM expects a variable-length
list of offset/value pairs and writes them in sequence.  The previous
code would only check whether the first entry was valid, effectively
allowing userspace to write unrestricted registers of the MMIO space
by sending a multi-register write with a legal first register, with
potential security implications on Gen6 and 7 hardware.

Fix it by extending the drm_i915_cmd_descriptor table to represent
multi-register access and making validate_cmd() iterate for all
register offsets present in the command packet.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Only bit 27 of SCRATCH1 and bit 6 of ROW_CHICKEN3 are allowed to be
set because of security-sensitive bits we don't want userspace to mess
with.  On HSW hardware the whitelisted bits control whether atomic
read-modify-write operations are performed on L3 or on GTI, and when
set to L3 (which can be 10x-30x better performing than on GTI,
depending on the application) require great care to avoid a system
hang, so we currently program them to be handled on GTI by default.

Beignet can immediately start taking advantage of this change to
enable L3 atomics.  Mesa should eventually switch to L3 atomics too,
but a number of non-trivial changes are still required so it will
continue using GTI atomics for now.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In some cases it might be unnecessary or dangerous to give userspace
the right to write arbitrary values to some register, even though it
might be desirable to give it control of some of its bits.  This patch
extends the register whitelist entries to contain a mask/value pair in
addition to the register offset.  For registers with non-zero mask,
any LRM writes and LRI writes where the bits of the immediate given by
the mask don't match the specified value will be rejected.

This will be used in my next patch to grant userspace partial write
access to some sensitive registers.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Until now the software command checker assumed that commands could
read or write at most a single register per packet.  This is not
necessarily the case, MI_LOAD_REGISTER_IMM expects a variable-length
list of offset/value pairs and writes them in sequence.  The previous
code would only check whether the first entry was valid, effectively
allowing userspace to write unrestricted registers of the MMIO space
by sending a multi-register write with a legal first register, with
potential security implications on Gen6 and 7 hardware.

Fix it by extending the drm_i915_cmd_descriptor table to represent
multi-register access and making validate_cmd() iterate for all
register offsets present in the command packet.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the madvise logic out of the execbuffer main path into the
relatively rare allocation path, making the execbuffer manipulation less
fragile.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

vmap_batch() calculates amount of needed pages for the mapping
we are going to create. And it uses this page count as an
argument for the for_each_sg_pages() macro. The macro takes the number
of sg list entities as an argument, not the page count. So we ended
up iterating through all the pages on the mapped object, corrupting
memory past the smaller pages[] array.

Fix this by bailing out when we have enough pages.

This regression has been introduced in

commit 17cabf57
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed Jan 14 11:20:57 2015 +0000

    drm/i915: Trim the command parser allocations

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently, the command parser tries to create a secondary batch exactly
as large as the original, and vmap both. This is open to abuse by
userspace using extremely large batch objects, but only executing very
short batches. For example, this would be if userspace were to implement
a command submission ringbuffer. However, we only need to allocate pages
for just the contents of the command sequence in the batch - all
relocations copied to the secondary batch will reference the original
batch and so there can be no access to the secondary batch outside of
the explicit execution region.

Testcase: igt/gem_exec_big #ivb,byt,hsw
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88308Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This will allow us to read the number of dispatched compute threads
for GL_ARB_pipeline_statistics_query.
Signed-off-by: NJordan Justen <jordan.l.justen@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move it to a separate function since the main do_execbuffer function
already has so much going on.

v2:
- Move pin/unpin calls inside i915_parse_cmds() (Chris W, v4 7/7
  feedback)

Issue: VIZ-4719
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: NJon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Previously we couldn't trust the user-supplied batch length because
it came directly from userspace (i.e. untrusted code). It would have
affected what commands software parsed without regard to what hardware
would actually execute, leaving a potential hole.

With the parser now copying the user supplied batch buffer and writing
MI_NOP commands to any space after the copied region, we can safely use
the batch length input. This should be a performance win as the actual
batch length is frequently much smaller than the allocated object size.

v2: Fix handling of non-zero batch_start_offset

Issue: VIZ-4719
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: NJon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch sets up all of the tracking and copying necessary to
use batch pools with the command parser and dispatches the copied
(shadow) batch to the hardware.

After this patch, the parser is in 'enabling' mode.

Note that performance takes a hit from the copy in some cases
and will likely need some work. At a rough pass, the memcpy
appears to be the bottleneck. Without having done a deeper
analysis, two ideas that come to mind are:
1) Copy sections of the batch at a time, as they are reached
   by parsing. Might improve cache locality.
2) Copy only up to the userspace-supplied batch length and
   memset the rest of the buffer. Reduces the number of reads.

v2:
- Remove setting the capacity of the pool
- One global pool instead of per-ring pools
- Replace batch_obj with shadow_batch_obj and hook into eb->vmas
- Memset any space in the shadow batch beyond what gets copied
- Rebased on execlist prep refactoring

v3:
- Rebase on chained batch handling
- Squash in setting the secure dispatch flag
- Add a note about the interaction w/secure dispatch pinning
- Check for request->batch_obj == NULL in i915_gem_free_request

v4:
- Fix read domains for shadow_batch_obj
- Remove the set_to_gtt_domain call from i915_parse_cmds
- ggtt_pin/unpin in the parser block to simplify error handling
- Check USES_FULL_PPGTT before setting DISPATCH_SECURE flag
- Remove i915_gem_batch_pool_put calls

v5:
- Move 'pending_read_domains |= I915_GEM_DOMAIN_COMMAND' after
  the parser (danvet, from v4 0/7 feedback)

Issue: VIZ-4719
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: NJon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Was missing.

Issue: VIZ-4701
Signed-off-by: NMichael H. Nguyen <michael.h.nguyen@intel.com>
Reviewed-by: NJon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that sanity prevails and we have the clean split between software
init and starting the engines we can drop all the "have we allocate
this struct already?" nonsense.

Execlist code could benefit quite a bit more still, but that's for
another patch.
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The predicate source registers are needed to implement conditional
rendering without stalling. The two source registers are used to load
the previous values of the PS_DEPTH_COUNT register saved from
PIPE_CONTROL commands. These can then be compared and used to set the
predicate enable bit via the MI_PREDICATE command.

The command parser version number is increased to 2 to make it easier
to detect the new functionality in user space.
Signed-off-by: NNeil Roberts <neil@linux.intel.com>
Reviewed-by: Brad Volkin <bradley.d.volkin@intel.com> (v1)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

libva uses chained batch buffers in a way that the command parser
can't generally handle. Fortunately, libva doesn't need to write
registers from batch buffers in the way that mesa does, so this
patch causes the driver to fall back to non-secure dispatch if
the parser detects a chained batch buffer.

Note: The 2nd hunk to munge the error code of the parser looks a bit
superflous. At least until we have the batch copy code ready and can
run the cmd parser in granting mode. But it isn't since we still need
to let existing libva buffers pass (though not with elevated privs
ofc!).

Testcase: igt/gem_exec_parse/chained-batch
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
[danvet: Add note - this confused me in review and Brad clarified
things (after a few mails ...).]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch fix spelling typos found in drm.xml.
It is because the file is generated from comments in
source codes, I have to fix the typos within source files.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ring init and cleanup are not balanced because we re-init the rings on
resume without having cleaned them up on suspend. This leads to the
driver leaking the parser's hash tables with a kmemleak signature such
as this:

unreferenced object 0xffff880405960980 (size 32):
  comm "systemd-udevd", pid 516, jiffies 4294896961 (age 10202.044s)
  hex dump (first 32 bytes):
    d0 85 46 c0 ff ff ff ff 00 00 00 00 00 00 00 00  ..F.............
    98 60 28 04 04 88 ff ff 00 00 00 00 00 00 00 00  .`(.............
  backtrace:
    [<ffffffff81816f9e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811fa678>] kmem_cache_alloc_trace+0x168/0x2f0
    [<ffffffffc03e20a5>] i915_cmd_parser_init_ring+0x2a5/0x3e0 [i915]
    [<ffffffffc04088a2>] intel_init_ring_buffer+0x202/0x470 [i915]
    [<ffffffffc040c998>] intel_init_vebox_ring_buffer+0x1e8/0x2b0 [i915]
    [<ffffffffc03eff59>] i915_gem_init_hw+0x2f9/0x3a0 [i915]
    [<ffffffffc03f0057>] i915_gem_init+0x57/0x1d0 [i915]
    [<ffffffffc045e26a>] i915_driver_load+0xc0a/0x10e0 [i915]
    [<ffffffffc02e0d5d>] drm_dev_register+0xad/0x100 [drm]
    [<ffffffffc02e3b9f>] drm_get_pci_dev+0x8f/0x200 [drm]
    [<ffffffffc03c934b>] i915_pci_probe+0x3b/0x60 [i915]
    [<ffffffff81436725>] local_pci_probe+0x45/0xa0
    [<ffffffff81437a69>] pci_device_probe+0xd9/0x130
    [<ffffffff81524f4d>] driver_probe_device+0x12d/0x3e0
    [<ffffffff815252d3>] __driver_attach+0x93/0xa0
    [<ffffffff81522e1b>] bus_for_each_dev+0x6b/0xb0

This patch extends the current convention of checking whether a
resource is already allocated before allocating it during ring init.
Longer term it might make sense to only init the rings once.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83794Tested-by: NKari Suvanto <kari.tj.suvanto@gmail.com>
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The other paths in the command parser that reject a batch all
log a message indicating the reason. We simply missed this one.
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In commit

commit 896ab1a5
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Aug 6 15:04:51 2014 +0200

    drm/i915: Fix up checks for aliasing ppgtt

it looks like we accidentally inverted the check that the command
parser should only run when the driver enables some form of PPGTT.

Testcase: igt/gem_exec_parse
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
[danvet: Also drop the comment right above, all production vlv now
have hw ppgtt enabled.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A subsequent patch will no longer initialize the aliasing ppgtt if we
have full ppgtt enabled, since we simply don't need that any more.

Unfortunately a few places check for the aliasing ppgtt instead of
checking for ppgtt in general. Fix them up.

One special case are the gtt offset and size macros, which have some
code to remap the aliasing ppgtt to the global gtt. The aliasing ppgtt
is _not_ a logical address space, so passing that in as the vm is
plain and simple a bug. So just WARN about it and carry on - we have a
gracefully fall-through anyway if we can't find the vma.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>