The ONLY places that guc_id (aka hw_id) should be used are those where
the value or address is determined by and shared with the GuC firmware;
specifically, when filling in the GuC-context-descriptor or the GuC
addon data, or putting an entry in the GuC's work queue.

It need not (and therefore should not) be used to index GuC statistics
or similar host-managed tracking data. In particular, i915_guc_submit()
produces (and debugfs decodes) GuC submission statistics which should be
indexed by driver-engine-id rather then guc-engine-id.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466432287-5799-1-git-send-email-david.s.gordon@intel.com

During a hibernate/resume cycle, the whole system is reset, including
the GuC and the doorbell hardware. Then the system is booted up, drivers
are loaded, etc -- the GuC firmware may be loaded and set running at
this point. But then, the booted kernel is replaced by the hibernated
image, and this resumed kernel will also try to reload the GuC firmware
(which will fail). To recover, we reset the GuC and try again (which
should work). But this GuC reset doesn't also reset the doorbell
hardware, so it can be left in a state inconsistent with that assumed
by the driver and/or the newly-loaded GuC firmware.

It would be better if the GuC reset also cleared all doorbell state,
but that's not how the hardware currently works; also, the driver cannot
directly reprogram the doorbell hardware (only the GuC can do that).

So this patch cycles through all doorbells, assigning and releasing each
in turn, so that all the doorbell hardware is left in a consistent
state, no matter how it was programmed by the previously-running kernel
and/or GuC firmware.

v2: don't use kmap_atomic() now that client page 0 is kept mapped.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465837054-16245-2-git-send-email-david.s.gordon@intel.com

This version doesn't update the doorbell bitmap, as that will
be done when the selected doorbell is associated with a client.

The call is now slightly earlier, just on the general principle
that potentially-failing operations should be done as early as
possible, to eliminate late failures and simplify recovery.
Suggested-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

This patch refactors the driver's handling and tracking of doorbells, in
preparation for a later one which will resolve a suspend-resume issue.

There are three resources to be managed:
1. Cachelines: a single line within the client-object's page 0
   is snooped by doorbell hardware for writes from the host.
2. Doorbell registers: each defines one cacheline to be snooped.
3. Bitmap: tracks which doorbell registers are in use.

The doorbell setup/teardown protocol starts with:
1. Pick a cacheline: select_doorbell_cacheline()
2. Find an available doorbell register: assign_doorbell()
(These values are passed to the GuC via the shared context
descriptor; this part of the sequence remains unchanged).

3. Update the bitmap to reflect registers-in-use
4. Prepare the cacheline for use by setting its status to ENABLED
5. Ask the GuC to program the doorbell to snoop the cacheline

and of course teardown is very similar:
6. Set the cacheline to DISABLED
7. Ask the GuC to reprogram the doorbell to stop snooping
8. Record that the doorbell is not in use.

Operations 6-8 (guc_disable_doorbell(), host2guc_release_doorbell(), and
release_doorbell()) were called in sequence from guc_client_free(), but
are now moved into the teardown phase of the common function.

Steps 4-5 (guc_init_doorbell() and host2guc_allocate_doorbell()) were
similarly done as sequential steps in guc_client_alloc(), but since it
turns out that we don't need to be able to do them separately they're
now collected into the setup phase of the common function.

The only new code (and new capability) is the block tagged
    /* Update the GuC's idea of the doorbell ID */
i.e. we can now *change* the doorbell register used by an existing
client, whereas previously it was set once for the entire lifetime
of the client. We will use this new feature in the next patch.

v2: Trivial independent fixes pushed ahead as separate patches.
    MUCH longer commit message :) [Tvrtko Ursulin]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Just code movement, no actual change to the function. This is in
preparation for the next patch, which will reorganise all the other
doorbell code, but doesn't change this function. So let's shuffle it
down near its caller rather than leaving it mixed in with the setup
code. Unlike the doorbell management code, this function is somewhat
time-critical, so putting it near its caller may even yield a tiny
performance improvement.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

These registers are not actually writable by the CPU; only the GuC can
actually program them. So let's not do writes that have no effect.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Bitmap operators are overkill when touching only one bit.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

There are four non-static functions in i915_guc_submission.c that take a
'dev' parameter. All are called only from GuC loader code, and can be
easily converted to accept 'dev_priv' instead.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465579766-31595-1-git-send-email-david.s.gordon@intel.com

Convert all static functions in i915_guc_submission.c that currently
take a 'dev' pointer to take 'dev_priv' instead (there are three,
guc_client_alloc(), guc_client_free(), and gem_allocate_guc_obj().
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

When resetting and reloading the GuC, the GuC submission management code
also needs to destroy and recreate the GuC client(s). Currently this is
done by a separate call from the GuC loader, but really, it's just an
internal detail of the submission code. So here we remove the call from
the loader (which is too late, really, because the GuC has already been
reloaded at this point) and put it into guc_submission_init() instead.
This means that any preexisting client is destroyed *before* the GuC
(re)load and then recreated after, iff the firmware was successfully
loaded. If the GuC reload fails, we don't recreate the client, so
fallback to execlists mode (if active) won't leak the client object
(previously, the now-unusable client would have been left allocated,
and leaked if the driver were unloaded).
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Just move the kernel_context member of drm_i915_private next to the
engines it is associated with.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-7-git-send-email-chris@chris-wilson.co.uk

We want to give a name to the currently anonymous per-engine struct
inside the context, so that we can assign it to a local variable and
save clumsy typing. The name we have chosen is intel_context as it
reflects the HW facing portion of the context state (the logical context
state, the registers, the ringbuffer etc).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-4-git-send-email-chris@chris-wilson.co.uk

Our goal is to rename the anonymous per-engine struct beneath the
current intel_context. However, after a lively debate resolving around
the confusion between intel_context_engine and intel_engine_context, the
realisation is that the two structs target different users. The outer
struct is API / user facing, and so carries the higher level GEM
information. The inner struct is hw facing. Thus we want to name the
inner struct intel_context and the outer one i915_gem_context. As the
first step, we need to rename the current struct:

	s/struct intel_context/struct i915_gem_context/

which fits much better with its constructors already conveying the
i915_gem_context prefix!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-1-git-send-email-chris@chris-wilson.co.uk

Mostly little optimisations and future-proofing against code breakage.
For instance, if the driver is correctly following the submission
protocol, the "out of space" condition is impossible, so the previous
runtime WARN_ON() is promoted to a GEM_BUG_ON() for a more dramatic
effect in development and less impact in end-user systems.

Similarly we can make alignment checking more stringent and replace
other WARN_ON() conditions that don't relate to the runtime hardware
state with either BUILD_BUG_ON() for compile-time-detectable issues, or
GEM_BUG_ON() for logical "can't happen" errors.

With those changes, we can convert it to void, as suggested by Chris
Wilson, and update the calling code appropriately.

v2:
    Note that we're now putting the request seqno in the "fence_id"
    field of each GuC-work-item, in case it turns up somewhere useful
    (e.g. in a GuC log) [Tvrtko Ursulin].
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Rather than wait to see whether more space becomes available in the GuC
submission workqueue, we can just return -EAGAIN and let the caller try
again in a little while. This gets rid of an uninterruptable sleep in
the polling code :)

We'll also add a counter to the GuC client statistics, to see how often
we find the WQ full.

v2:
    Flag the likely() code path (Tvtrko Ursulin).

v4:
    Add/update comments about failure counters (Tvtrko Ursulin).
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The knowledge of how to derive the relevant client from the request
should be localised within i915_guc_submission.c; the LRC code shouldn't
have to know about the internal details of the GuC submission process.
And all the information the GuC code needs should be encapsulated in (or
reachable from) the request.

v2:
    GEM_BUG_ON() for bad GuC client (Tvrtko Ursulin).
    Add/update kerneldoc explaining check_space/submit protocol
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Split the function of "enable_guc_submission" into two separate
options.  The new one ("enable_guc_loading") controls only the
*fetching and loading* of the GuC firmware image. The existing
one is redefined to control only the *use* of the GuC for batch
submission once the firmware is loaded.

In addition, the degree of control has been refined from a simple
bool to an integer key, allowing several options:
-1 (default)     whatever the platform default is
 0  DISABLE      don't load/use the GuC
 1  BEST EFFORT  try to load/use the GuC, fallback if not available
 2  REQUIRE      must load/use the GuC, else leave the GPU wedged

The new platform default (as coded here) will be to attempt to
load the GuC iff the device has a GuC that requires firmware,
but not yet to use it for submission. A later patch will change
to enable it if appropriate.

v4:
    Changed some error-message levels, mostly ERROR->INFO, per
    review comments by Tvrtko Ursulin.

v5:
    Dropped one more error message, disabled GuC submission on
    hypothetical firmware-free devices [Tvrtko Ursulin].

v6:
    Logging tidy by Tvrtko Ursulin:
     * Do not log falling back to execlists when wedging the GPU.
     * Do not log fw load errors when load was disabled by user.
     * Pass down some error code from fw load for log message to
       make more sense.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v5)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Tested-by: NFiedorowicz, Lukasz <lukasz.fiedorowicz@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v5)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com> (v6)

Pass drm_i915_private to the uncore init/fini routines and their
subservients as it is their native type.

   text    data     bss     dec     hex filename
6309978 3578778  696320 10585076         a183f4 vmlinux
6309530 3578778  696320 10584628         a18234 vmlinux

a modest 400 bytes of saving, but 60 lines of code deleted!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1462885804-26750-1-git-send-email-chris@chris-wilson.co.uk

Propagate the real error from drm_gem_object_init(). Note this also
fixes some confusion in the error return from i915_gem_alloc_object...

v2:
(Matthew Auld)
  - updated new users of gem_alloc_object from latest drm-nightly
  - replaced occurrences of IS_ERR_OR_NULL() with IS_ERR()
v3:
(Joonas Lahtinen)
  - fix double "From:" in commit message
  - add goto teardown path
v4:
(Matthew Auld)
  - rebase with i915_gem_alloc_object name change
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461587533-8841-1-git-send-email-matthew.auld@intel.com
[Joonas: Removed spurious " = NULL" from _init() function]
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Because having both i915_gem_object_alloc() and i915_gem_alloc_object()
(with different return conventions) is just too confusing!

(i915_gem_object_alloc() is the low-level memory allocator, and remains
unchanged, whereas i915_gem_alloc_object() is a constructor that ALSO
initialises the newly-allocated object.)
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461348872-4702-1-git-send-email-david.s.gordon@intel.com

Tidying up guc_init_proc_desc() and adding commentary to the client
structure after the recent change in GuC page mapping strategy.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461078516-28678-1-git-send-email-david.s.gordon@intel.comReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Now that we keep the GuC client process descriptor permanently mapped,
we don't really need to keep a local copy of the GuC's work-queue-head.
So we can simplify the code a little by not doing this.
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Don't use kmap_atomic() for doorbell & process descriptor access.
This patch fixes the BUG shown below, where the thread could sleep
while holding a kmap_atomic mapping. In order not to need to call
kmap_atomic() in this code path, we now set up a permanent kernel
mapping of the shared doorbell and process-descriptor page, and
use that in all doorbell and process-descriptor related code.

  BUG: scheduling while atomic: gem_close_race/1941/0x00000002
  Modules linked in: hid_generic usbhid i915 asix usbnet libphy mii
    i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt
    sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm coretemp i2c_hid
    hid video pinctrl_sunrisepoint pinctrl_intel acpi_pad nls_iso8859_1
    e1000e ptp psmouse pps_core ahci libahci
  CPU: 0 PID: 1941 Comm: gem_close_race Tainted: G     U 4.4.0-160121+ #123
  Hardware name: Intel Corporation Skylake Client platform/Skylake AIO
    DDR3L RVP10, BIOS SKLSE2R1.R00.X100.B01.1509220551 09/22/2015
    0000000000013e40 ffff880166c27a78 ffffffff81280d02 ffff880172c13e40
    ffff880166c27a88 ffffffff810c203a ffff880166c27ac8 ffffffff814ec808
    ffff88016b7c6000 ffff880166c28000 00000000000f4240 0000000000000001
  Call Trace:
    [<ffffffff81280d02>] dump_stack+0x4b/0x79
    [<ffffffff810c203a>] __schedule_bug+0x41/0x4f
    [<ffffffff814ec808>] __schedule+0x5a8/0x690
    [<ffffffff814ec927>] schedule+0x37/0x80
    [<ffffffff814ef3fd>] schedule_hrtimeout_range_clock+0xad/0x130
    [<ffffffff81090be0>] ? hrtimer_init+0x10/0x10
    [<ffffffff814ef3f1>] ?  schedule_hrtimeout_range_clock+0xa1/0x130
    [<ffffffff814ef48e>] schedule_hrtimeout_range+0xe/0x10
    [<ffffffff814eef9b>] usleep_range+0x3b/0x40
    [<ffffffffa01ec109>] i915_guc_wq_check_space+0x119/0x210 [i915]
    [<ffffffffa01da47c>] intel_logical_ring_alloc_request_extras+0x5c/0x70 [i915]
    [<ffffffffa01cdbf1>] i915_gem_request_alloc+0x91/0x170 [i915]
    [<ffffffffa01c1c07>] i915_gem_do_execbuffer.isra.25+0xbc7/0x12a0 [i915]
    [<ffffffffa01cb785>] ?  i915_gem_object_get_pages_gtt+0x225/0x3c0 [i915]
    [<ffffffffa01d1fb6>] ? i915_gem_pwrite_ioctl+0xd6/0x9f0 [i915]
    [<ffffffffa01c2e68>] i915_gem_execbuffer2+0xa8/0x250 [i915]
    [<ffffffffa00f65d8>] drm_ioctl+0x258/0x4f0 [drm]
    [<ffffffffa01c2dc0>] ? i915_gem_execbuffer+0x340/0x340 [i915]
    [<ffffffff8111590d>] do_vfs_ioctl+0x2cd/0x4a0
    [<ffffffff8111eac2>] ? __fget+0x72/0xb0
    [<ffffffff81115b1c>] SyS_ioctl+0x3c/0x70
    [<ffffffff814effd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
  ------------[ cut here ]------------

v4:
  Only tear down doorbell & kunmap() client object if we actually
  succeeded in allocating a client object (Tvrtko Ursulin)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93847Original-version-by: NAlex Dai <yu.dai@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Tvtrko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Having provided for_each_engine_id() for cases where the third (id)
argument is useful, we can now replace all the remaining instances with
a simpler version that takes only two parameters. In many cases, this
also allows the elimination of the local variable used in the iterator
(usually 'i').

v2:
    s/dev_priv/(dev_priv__)/ in body of for_each_engine_masked() [Chris Wilson]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458757194-17783-2-git-send-email-david.s.gordon@intel.com

Equivalent to the existing for_each_engine() macro, this will replace
the latter wherever the third argument *is* actually wanted (in most
places, it is not used). The third argument is renamed to emphasise
that it is an engine id (type enum intel_engine_id). All the callers of
the macro that actually need the third argument are updated to use this
version, and the argument (generally 'i') is also updated to be 'id'.
Other callers (where the third argument is unused) are untouched for
now; they will be updated in the next patch.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Some trivial ones, first pass done with Coccinelle:

@@
@@
(
- I915_NUM_RINGS
+ I915_NUM_ENGINES
|
- intel_ring_flag
+ intel_engine_flag
|
- for_each_ring
+ for_each_engine
|
- i915_gem_request_get_ring
+ i915_gem_request_get_engine
|
- intel_ring_idle
+ intel_engine_idle
|
- i915_gem_reset_ring_status
+ i915_gem_reset_engine_status
|
- i915_gem_reset_ring_cleanup
+ i915_gem_reset_engine_cleanup
|
- init_ring_lists
+ init_engine_lists
)

But that didn't fully work so I cleaned it up with:

for f in *.[hc]; do sed -i -e s/I915_NUM_RINGS/I915_NUM_ENGINES/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_request_get_ring/i915_gem_request_get_engine/ $f; done
for f in *.[hc]; do sed -i -e s/intel_ring_flag/intel_engine_flag/ $f; done
for f in *.[hc]; do sed -i -e s/intel_ring_idle/intel_engine_idle/ $f; done
for f in *.[hc]; do sed -i -e s/init_ring_lists/init_engine_lists/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_reset_ring_cleanup/i915_gem_reset_engine_cleanup/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_reset_ring_status/i915_gem_reset_engine_status/ $f; done

v2: Rebase.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

below and a couple manual fixups.

@@
identifier I, J;
@@
struct I {
...
- struct intel_engine_cs *J;
+ struct intel_engine_cs *engine;
...
}
@@
identifier I, J;
@@
struct I {
...
- struct intel_engine_cs J;
+ struct intel_engine_cs engine;
...
}
@@
struct drm_i915_private *d;
@@
(
- d->ring
+ d->engine
)
@@
struct i915_execbuffer_params *p;
@@
(
- p->ring
+ p->engine
)
@@
struct intel_ringbuffer *r;
@@
(
- r->ring
+ r->engine
)
@@
struct drm_i915_gem_request *req;
@@
(
- req->ring
+ req->engine
)

v2: Script missed the tracepoint code - fixed up by hand.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Done by the Coccinelle script below plus a manual
intervention to GEN8_RING_SEMAPHORE_INIT.

@@
expression E;
@@
- struct intel_engine_cs *ring = E;
+ struct intel_engine_cs *engine = E;
<+...
- ring
+ engine
...+>
@@
@@
- struct intel_engine_cs *ring;
+ struct intel_engine_cs *engine;
<+...
- ring
+ engine
...+>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Previously GuC uses ring id as engine id because of same definition.
But this is not true since this commit:

commit de1add36
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Fri Jan 15 15:12:50 2016 +0000

    drm/i915: Decouple execbuf uAPI from internal implementation

Added GuC engine id into GuC interface to decouple it from ring id used
by driver.

v2: Keep ring name print out in debugfs; using for_each_ring() where
    possible to keep driver consistent. (Chris W.)
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453579094-29860-1-git-send-email-yu.dai@intel.com

Since:

commit 82352e90
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Fri Jan 15 17:12:45 2016 +0000

    drm/i915: Cache LRC state page in the context

and:

commit 0eb973d3
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Fri Jan 15 15:10:28 2016 +0000

    drm/i915: Cache ringbuffer GTT VMA

We can also remove the ring buffer start updates on every
context update since the address will not change for the
duration of the LRC pin.

For GuC we can remove the update altogether because it
only cares about the ring buffer start.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Alex Dai <yu.dai@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1453466567-33369-1-git-send-email-tvrtko.ursulin@linux.intel.com

Now that we've eliminated a lot of uses of ring->default_context,
we can eliminate the pointer itself.

All the engines share the same default intel_context, so we can just
keep a single reference to it in the dev_priv structure rather than one
in each of the engine[] elements. This make refcounting more sensible
too, as we now have a refcount of one for the one pointer, rather than
a refcount of one but multiple pointers.

From an idea by Chris Wilson.

v2:	transform an extra instance of ring->default_context introduced by
    42f1cae8 drm/i915: Restore inhibiting the load of the default context
    That patch's commentary includes:
	v2: Mark the global default context as uninitialized on GPU reset so
	    that the context-local workarounds are reloaded upon re-enabling
    The code implementing that now also benefits from the replacement of
    the multiple (per-ring) pointers to the default context with a single
    pointer to the unique kernel context.

v4:	Rebased, remove underused local (Nick Hoath)
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NNick Hoath <nicholas.hoath@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1453230175-19330-3-git-send-email-david.s.gordon@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GuC needs to know which registers and how they will be saved and
restored during event such as engine reset or power state changes.
For now only the base address of reg state is initialized. The
detail register table probably will be setup in future GuC TDR or
Preemption patch series.
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-5-git-send-email-yu.dai@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GuC supports different scheduling policies for its four internal
queues. Currently these have been set to the same default values
as KMD_NORMAL queue.

Particularly POLICY_MAX_NUM_WI is set to 15 to match GuC internal
maximum submit queue numbers to avoid an out-of-space problem.
This value indicates max number of work items allowed to be queued
for one DPC process. A smaller value will let GuC schedule more
frequently while a larger number may increase chances to optimize
cmds (such as collapse cmds from same lrc) with risks that keeps
CS idle.

v1: tidy up code
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-4-git-send-email-yu.dai@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The GuC firmware uses this for various purposes. The ADS itself is
a chunk of memory created by driver to share with GuC. Its members
are usually addresses telling where GuC to access them, including
things like scheduler policies, register list that will be saved
and restored during reset etc.

This is the first patch of a series to enable GuC ADS. For now, we
only create the ADS obj whilst keep it disabled.

v1: remove dead code checking return of kmap_atomic (Chris Wilson)
v2: use kmap instead of the atomic version of it.
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-3-git-send-email-yu.dai@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Split GuC work queue space checking from submission and move it to
ring_alloc_request_extras. The reason is that failure in later
i915_add_request() won't be handled. In the case timeout happens,
driver can return early in order to handle the error.

v1: Move wq_reserve_space to ring_reserve_space
v2: Move wq_reserve_space to alloc_request_extras (Chris Wilson)
v3: The work queue head pointer is cached by driver now. So we can
    quickly return if space is available.
    s/reserve/check/g (Dave Gordon)
v4: Update cached wq head after ring doorbell; check wq space before
    ring doorbell in case unexpected error happens; call wq space
    check only when GuC submission is enabled. (Dave Gordon)
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450295155-10050-1-git-send-email-yu.dai@intel.comReviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit 344df980 ("drm/i915/skl: Disable coarse power gating up until F0")
failed to take into account that the same workaround is used in guc
when forcewake is sampled.

Wrap the condition check inside a macro and use it in both places
to fix the guc side scope.

Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450286318-6854-1-git-send-email-mika.kuoppala@intel.com

In various places, a single page of a (regular) GEM object is mapped into
CPU address space and updated. In each such case, either the page or the
the object should be marked dirty, to ensure that the modifications are
not discarded if the object is evicted under memory pressure.

The typical sequence is:
	va = kmap_atomic(i915_gem_object_get_page(obj, pageno));
	*(va+offset) = ...
	kunmap_atomic(va);

Here we introduce i915_gem_object_get_dirty_page(), which performs the
same operation as i915_gem_object_get_page() but with the side-effect
of marking the returned page dirty in the pagecache.  This will ensure
that if the object is subsequently evicted (due to memory pressure),
the changes are written to backing store rather than discarded.

Note that it works only for regular (shmfs-backed) GEM objects, but (at
least for now) those are the only ones that are updated in this way --
the objects in question are contexts and batchbuffers, which are always
shmfs-backed.

Separate patches deal with the cases where whole objects are (or may
be) dirtied.

v3: Mark two more pages dirty in the page-boundary-crossing
    cases of the execbuffer relocation code [Chris Wilson]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1449773486-30822-2-git-send-email-david.s.gordon@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For now, remove the spinlocks that protected the GuC's
statistics block and work queue; they are only accessed
by code that already holds the global struct_mutex, and
so are redundant (until the big struct_mutex rewrite!).

The specific problem that the spinlocks caused was that
if the work queue was full, the driver would try to
spinwait for one jiffy, but with interrupts disabled the
jiffy count would not advance, leading to a system hang.
The issue was found using test case igt/gem_close_race.

The new version will usleep() instead, still holding
the struct_mutex but without any spinlocks.

v4: Reorganize commit message (Dave Gordon)
v3: Remove unnecessary whitespace churn
v2: Clean up wq_lock too
v1: Clean up host2guc lock as well
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449104189-27591-1-git-send-email-yu.dai@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448461290-12333-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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