drm/i915: Tidy reporting busy status during i915_gem_retire_requests()

As we know by inspection whether any engine is still busy as we retire
all the requests, we can pass that information back via return value
rather than check again afterwards.

v2: A little more polish missed in patch splitting

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160827075401.16470-1-chris@chris-wilson.co.uk

drm/i915: Allow the user to pass a context to any ring

With full-ppgtt, we want the user to have full control over their memory
layout, with a separate instance per context. Forcing them to use a
shared memory layout for !RCS not only duplicates the amount of work we
have to do, but also defeats the memory segregation on offer.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822080350.4964-4-chris@chris-wilson.co.uk
Reviewed-by: John Harrison <john.c.harrison@intel.com>
Reviewed-by: Thomas Daniel <thomas.daniel@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Add GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE to SNB

According to the CI test machines, SNB also uses the
GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE value to report a bad
GEN6_PCODE_MIN_FREQ_TABLE request.

[  157.744641] WARNING: CPU: 5 PID: 9238 at
drivers/gpu/drm/i915/intel_pm.c:7760 sandybridge_pcode_write+0x141/0x200 [i915]
[  157.744642] Missing switch case (16) in gen6_check_mailbox_status
[  157.744642] Modules linked in: snd_hda_intel i915 ax88179_178a usbnet mii x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec snd_hwdep snd_hda_core mei_me lpc_ich snd_pcm mei broadcom bcm_phy_lib tg3 ptp pps_core [last unloaded: vgem]
[  157.744658] CPU: 5 PID: 9238 Comm: drv_hangman Tainted: G     U  W 4.8.0-rc3-CI-CI_DRM_1589+ #1
[  157.744658] Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
[  157.744659]  0000000000000000 ffff88011f093a98 ffffffff81426415 ffff88011f093ae8
[  157.744662]  0000000000000000 ffff88011f093ad8 ffffffff8107d2a6 00001e50810d3c9f
[  157.744663]  ffff880128680000 0000000000000008 0000000000000000 ffff88012868a650
[  157.744665] Call Trace:
[  157.744669]  [<ffffffff81426415>] dump_stack+0x67/0x92
[  157.744672]  [<ffffffff8107d2a6>] __warn+0xc6/0xe0
[  157.744673]  [<ffffffff8107d30a>] warn_slowpath_fmt+0x4a/0x50
[  157.744685]  [<ffffffffa0029831>] sandybridge_pcode_write+0x141/0x200 [i915]
[  157.744697]  [<ffffffffa002a88a>] intel_enable_gt_powersave+0x64a/0x1330 [i915]
[  157.744712]  [<ffffffffa006b4cb>] ? i9xx_emit_request+0x1b/0x80 [i915]
[  157.744725]  [<ffffffffa0055ed3>] __i915_add_request+0x1e3/0x370 [i915]
[  157.744738]  [<ffffffffa00428bd>] i915_gem_do_execbuffer.isra.16+0xced/0x1b80 [i915]
[  157.744740]  [<ffffffff811a232e>] ? __might_fault+0x3e/0x90
[  157.744752]  [<ffffffffa0043b72>] i915_gem_execbuffer2+0xc2/0x2a0 [i915]
[  157.744753]  [<ffffffff815485b7>] drm_ioctl+0x207/0x4c0
[  157.744765]  [<ffffffffa0043ab0>] ? i915_gem_execbuffer+0x360/0x360 [i915]
[  157.744767]  [<ffffffff810ea4ad>] ?  debug_lockdep_rcu_enabled+0x1d/0x20
[  157.744769]  [<ffffffff811fe09e>] do_vfs_ioctl+0x8e/0x680
[  157.744770]  [<ffffffff811a2377>] ? __might_fault+0x87/0x90
[  157.744771]  [<ffffffff811a232e>] ? __might_fault+0x3e/0x90
[  157.744773]  [<ffffffff810d3df2>] ?  trace_hardirqs_on_caller+0x122/0x1b0
[  157.744774]  [<ffffffff811fe6cc>] SyS_ioctl+0x3c/0x70
[  157.744776]  [<ffffffff8180fe69>] entry_SYSCALL_64_fastpath+0x1c/0xac

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97491
Fixes: 87660502f1a4 ("drm/i915/gen6+: Interpret mailbox error flags")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lyude <cpaul@redhat.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Link: http://patchwork.freedesktop.org/patch/msgid/20160826105926.3413-1-chris@chris-wilson.co.uk
Acked-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915/debugfs: Add panel delays for eDP

The eDP backlight and panel enable/disable delays are quite
useful to know when measuring time consumed by suspend/resume,
and while the information is printed to the kernel log as debug
messages, having this information in debugfs makes things easier.

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160823092356.7610-1-david.weinehall@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Add I915_PARAM_MMAP_GTT_VERSION to advertise unlimited mmaps

Now that we have working partial VMA and faulting support for all
objects, including fence support, advertise to userspace that it can
take advantage of unlimited GGTT mmaps.

v2: Make room in the kerneldoc for a more detailed explanation of the
limitations of the GTT mmap interface.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160825180519.11341-1-chris@chris-wilson.co.uk

drm/i915/skl: Update DDB values atomically with wms/plane attrs

Now that we can hook into update_crtcs and control the order in which we
update CRTCs at each modeset, we can finish the final step of fixing
Skylake's watermark handling by performing DDB updates at the same time
as plane updates and watermark updates.

The first major change in this patch is skl_update_crtcs(), which
handles ensuring that we order each CRTC update in our atomic commits
properly so that they honor the DDB flush order.

The second major change in this patch is the order in which we flush the
pipes. While the previous order may have worked, it can't be used in
this approach since it no longer will do the right thing. For example,
using the old ddb flush order:

We have pipes A, B, and C enabled, and we're disabling C. Initial ddb
allocation looks like this:

|   A   |   B   |xxxxxxx|

Since we're performing the ddb updates after performing any CRTC
disablements in intel_atomic_commit_tail(), the space to the right of
pipe B is unallocated.

1. Flush pipes with new allocation contained into old space. None
   apply, so we skip this
2. Flush pipes having their allocation reduced, but overlapping with a
   previous allocation. None apply, so we also skip this
3. Flush pipes that got more space allocated. This applies to A and B,
   giving us the following update order: A, B

This is wrong, since updating pipe A first will cause it to overlap with
B and potentially burst into flames. Our new order (see the code
comments for details) would update the pipes in the proper order: B, A.

As well, we calculate the order for each DDB update during the check
phase, and reference it later in the commit phase when we hit
skl_update_crtcs().

This long overdue patch fixes the rest of the underruns on Skylake.

Changes since v1:
 - Add skl_ddb_entry_write() for cursor into skl_write_cursor_wm()
Changes since v2:
 - Use the method for updating CRTCs that Ville suggested
 - In skl_update_wm(), only copy the watermarks for the crtc that was
   passed to us
Changes since v3:
 - Small comment fix in skl_ddb_allocation_overlaps()
Changes since v4:
 - Remove the second loop in intel_update_crtcs() and use Ville's
   suggestion for updating the ddb allocations in the right order
 - Get rid of the second loop and just use the ddb state as it updates
   to determine what order to update everything in (thanks for the
   suggestion Ville)
 - Simplify skl_ddb_allocation_overlaps()
 - Split actual overlap checking into it's own helper

Fixes: 0e8fb7ba7ca5 ("drm/i915/skl: Flush the WM configuration")
Fixes: 8211bd5bdf5e ("drm/i915/skl: Program the DDB allocation")
[omitting CC for stable, since this patch will need to be changed for
such backports first]

Testcase: kms_cursor_legacy
Testcase: plane-all-modeset-transition
Signed-off-by: Lyude <cpaul@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471961565-28540-2-git-send-email-cpaul@redhat.com

drm/i915: Move CRTC updating in atomic_commit into it's own hook

Since we have to write ddb allocations at the same time as we do other
plane updates, we're going to need to be able to control the order in
which we execute modesets on each pipe. The easiest way to do this is to
just factor this section of intel_atomic_commit_tail()
(intel_atomic_commit() for stable branches) into it's own function, and
add an appropriate display function hook for it.

Based off of Matt Rope's suggestions

Changes since v1:
 - Drop pipe_config->base.active check in intel_update_crtcs() since we
   check that before calling the function

Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
[omitting CC for stable, since this patch will need to be changed for
such backports first]
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471961565-28540-1-git-send-email-cpaul@redhat.com

drm/i915: Restore lost "Initialized i915" welcome message

A side effect of removing the midlayer from driver loading was the loss
of a useful message announcing to userspace that i915 had successfully
started, e.g.:

[drm] Initialized i915 1.6.0 20160425 for 0000:00:02.0 on minor 0

Reported-by: Timo Aaltonen <tjaalton@ubuntu.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Fixes: 8f460e2c78f2 ("drm/i915: Demidlayer driver loading")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Link: http://patchwork.freedesktop.org/patch/msgid/20160825072314.17402-1-chris@chris-wilson.co.uk
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Force RC6 restore after system resume and reset

In order for the RC6 autoenable worker to take any action, RC6 first
must be disabled. Upon resume or reset, the sw state may be stale and so
we require a forced restore.

Fixes: b7137e0cf1e5 ("drm/i915: Defer enabling rc6 til after we submit...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160824092701.19178-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915: Suppress DRM_ERROR for D_COMP write on Haswell

The D_COMP (render decompression) register write is followed by a status
check and another error (either that the decompression shutdown or the
lpll is enabled). Since we are followed by another, more pertinent,
error we can reduce the pcode timeout to a debug and squelch a sporadic
error message during suspend.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97465
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160824101607.13671-1-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.auld@intel.com>

Revert "drm/i915/fbc: Allow on unfenced surfaces, for recent gen"

This reverts commit 8678fdaf396c ("drm/i915/fbc: Allow on unfenced surfaces,
for recent gen") as Skylake has issues with unfenced FBC tracking (and
yes Skylake doesn't even enable FBC yet). Paulo would like to do a full
review of all existing workarounds to see if any more are missing prior
to allowing FBC on unfenced surfaces. In the meantime lets hope that all
framebuffers are idle and naturally fit within the mappable aperture.

Requested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Fixes: 8678fdaf396c ("drm/i915/fbc: Allow on unfenced surfaces...");
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160824180053.24239-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Eliminate redundant local variable definition

No functional change, just clean up.

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470897673-29292-3-git-send-email-dhinakaran.pandiyan@intel.com

drm/i915/dp: Dump DP link status when link training stages fail

A full dump of link status can be handy in debugging link training
failures. Let's add that to the debug messages when link training fails.

v2: Removing unrelated clean up (Jani)
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470343716-5574-3-git-send-email-dhinakaran.pandiyan@intel.com

drm/i915/dp: Add debug messages to print DP link training pattern

Currently we do not print the training pattern used in any of the DP link
training stages. Including this piece of information in debug messages will
help debugging.

Also, use the wrapper intel_dp_program_link_training_pattern() in
intel_dp_enable_port() instead of implementing it.

v2: Downgraded log level from error to debug (Chris)

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470343716-5574-2-git-send-email-dhinakaran.pandiyan@intel.com

drm/i915: free intel_fb

We need to free the allocated intel_fb in the error path, not
intel_fb->base. Otherwise we risk calling kfree with a non-kmalloc'd
address, which is bound to give us grief at some point.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471964444-24460-1-git-send-email-matthew.auld@intel.com

drm/i915/dvo: Remove dangling call to drm_encoder_cleanup()

If we hit the error path, we have never called drm_encoder_init() and so
have nothing to cleanup. Doing so hits a null dereference:

[   10.066261] BUG: unable to handle kernel NULL pointer dereference at 00000104
[   10.066273] IP: [<c16054b4>] mutex_lock+0xa/0x15
[   10.066287] *pde = 00000000
[   10.066295] Oops: 0002 [#1]
[   10.066302] Modules linked in: i915(+) video i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm iTCO_wdt iTCO_vendor_support ppdev evdev snd_intel8x0 snd_ac97_codec ac97_bus psmouse snd_pcm snd_timer snd pcspkr uhci_hcd ehci_pci soundcore sr_mod ehci_hcd serio_raw i2c_i801 usbcore i2c_smbus cdrom lpc_ich mfd_core rng_core e100 mii floppy parport_pc parport acpi_cpufreq button processor usb_common eeprom lm85 hwmon_vid autofs4
[   10.066378] CPU: 0 PID: 132 Comm: systemd-udevd Not tainted 4.8.0-rc3-00013-gef0e1ea #34
[   10.066389] Hardware name: MicroLink                               /D865GLC                        , BIOS BF86510A.86A.0077.P25.0508040031 08/04/2005
[   10.066401] task: f62db800 task.stack: f5970000
[   10.066409] EIP: 0060:[<c16054b4>] EFLAGS: 00010286 CPU: 0
[   10.066417] EIP is at mutex_lock+0xa/0x15
[   10.066424] EAX: 00000104 EBX: 00000104 ECX: 00000000 EDX: 80000000
[   10.066432] ESI: 00000000 EDI: 00000104 EBP: f5be8000 ESP: f5971b58
[   10.066439]  DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068
[   10.066446] CR0: 80050033 CR2: 00000104 CR3: 35945000 CR4: 000006d0
[   10.066453] Stack:
[   10.066459]  f503d740 f824dddf 00000000 f61170c0 f61170c0 f82371ae f850f40e 00000001
[   10.066476]  f61170c0 f5971bcc f5be8000 f9c2d401 00000001 f8236fcc 00000001 00000000
[   10.066491]  f5144014 f5be8104 00000008 f9c5267c 00000007 f61170c0 f5144400 f9c4ff00
[   10.066507] Call Trace:
[   10.066526]  [<f824dddf>] ? drm_modeset_lock_all+0x27/0xb3 [drm]
[   10.066545]  [<f82371ae>] ? drm_encoder_cleanup+0x1a/0x132 [drm]
[   10.066559]  [<f850f40e>] ? drm_atomic_helper_connector_reset+0x3f/0x5c [drm_kms_helper]
[   10.066644]  [<f9c2d401>] ? intel_dvo_init+0x569/0x788 [i915]
[   10.066663]  [<f8236fcc>] ? drm_encoder_init+0x43/0x20b [drm]
[   10.066734]  [<f9bf1fce>] ? intel_modeset_init+0x1436/0x17dd [i915]
[   10.066791]  [<f9b37636>] ? i915_driver_load+0x85a/0x15d3 [i915]
[   10.066846]  [<f9b3603d>] ? i915_driver_open+0x5/0x5 [i915]
[   10.066857]  [<c14af4d0>] ? firmware_map_add_entry.part.2+0xc/0xc
[   10.066868]  [<c1343daf>] ? pci_device_probe+0x8e/0x11c
[   10.066878]  [<c140cec8>] ? driver_probe_device+0x1db/0x62e
[   10.066888]  [<c120c010>] ? kernfs_new_node+0x29/0x9c
[   10.066897]  [<c13438e0>] ? pci_match_device+0xd9/0x161
[   10.066905]  [<c120c48b>] ? kernfs_create_dir_ns+0x42/0x88
[   10.066914]  [<c140d401>] ? __driver_attach+0xe6/0x11b
[   10.066924]  [<c1303b13>] ? kobject_add_internal+0x1bb/0x44f
[   10.066933]  [<c140d31b>] ? driver_probe_device+0x62e/0x62e
[   10.066941]  [<c140a2d2>] ? bus_for_each_dev+0x46/0x7f
[   10.066950]  [<c140c502>] ? driver_attach+0x1a/0x34
[   10.066958]  [<c140d31b>] ? driver_probe_device+0x62e/0x62e
[   10.066966]  [<c140b758>] ? bus_add_driver+0x217/0x32a
[   10.066975]  [<f8403000>] ? 0xf8403000
[   10.066982]  [<c140de27>] ? driver_register+0x5f/0x108
[   10.066991]  [<c1000493>] ? do_one_initcall+0x49/0x1f6
[   10.067000]  [<c1082299>] ? pick_next_task_fair+0x14b/0x2a3
[   10.067008]  [<c1603c8d>] ? __schedule+0x15c/0x4fe
[   10.067016]  [<c1604104>] ? preempt_schedule_common+0x19/0x3c
[   10.067027]  [<c11051de>] ? do_init_module+0x17/0x230
[   10.067035]  [<c1604139>] ? _cond_resched+0x12/0x1a
[   10.067044]  [<c116f9aa>] ? kmem_cache_alloc+0x8f/0x11f
[   10.067052]  [<c11051de>] ? do_init_module+0x17/0x230
[   10.067060]  [<c11703dd>] ? kfree+0x137/0x203
[   10.067068]  [<c110523d>] ? do_init_module+0x76/0x230
[   10.067078]  [<c10cadf3>] ? load_module+0x2a39/0x333f
[   10.067087]  [<c10cb8b2>] ? SyS_finit_module+0x96/0xd5
[   10.067096]  [<c1132231>] ? vm_mmap_pgoff+0x79/0xa0
[   10.067105]  [<c1001e96>] ? do_fast_syscall_32+0xb5/0x1b0
[   10.067114]  [<c16086a6>] ? sysenter_past_esp+0x47/0x75
[   10.067121] Code: c8 f7 76 c1 e8 8e cc d2 ff e9 45 fe ff ff 66 90 66 90 66 90 66 90 90 ff 00 7f 05 e8 4e 0c 00 00 c3 53 89 c3 e8 75 ec ff ff 89 d8 <ff> 08 79 05 e8 fa 0a 00 00 5b c3 53 89 c3 85 c0 74 1b 8b 03 83
[   10.067180] EIP: [<c16054b4>] mutex_lock+0xa/0x15 SS:ESP 0068:f5971b58
[   10.067190] CR2: 0000000000000104
[   10.067222] ---[ end trace 049f1f09da45a856 ]---

Reported-by: Meelis Roos <mroos@linux.ee>
Fixes: 580d8ed522e0 ("drm/i915: Give encoders useful names")
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160823092558.14931-1-chris@chris-wilson.co.uk

drm/i915: Cleanup crt disable sequence on hsw+

Instead of iterating overthe connectors manually, run the last part of
DDI disabling inside the crt post disable function.

This was meant to be addressed before submitting the other commit,
but I missed the review comments.

Fixes: fd6bbda9c7a4 ("drm/i915: Pass crtc_state and connector_state to encoder functions")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471961888-10771-2-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[mlankhorst: Fix extra whitespace between functions.]

drm/i915: Create a intel_encoder_find_connector helper function.

This makes the code in intel_sanitize_encoder slightly more readable.
This was meant to be addressed in fd6bbda9c7a4, but I missed that
review comment.

Fixes: fd6bbda9c7a4 ("drm/i915: Pass crtc_state and connector_state to encoder functions")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471961888-10771-1-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[mlankhorst: Fix unused variable reported by kbuild.]

io-mapping: Fixup for different names of writecombine

Somehow architectures can't agree on this. And for good measure make
sure we have a fallback which should work everywhere (fingers
crossed).

v2: Make it compile properly, needs a defined() for the #elif.

Fixes: ac96b5566926 ("io-mapping.h: s/PAGE_KERNEL_IO/PAGE_KERNEL/")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: linux-mm@kvack.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160823202233.4681-1-daniel.vetter@ffwll.ch

io-mapping.h: s/PAGE_KERNEL_IO/PAGE_KERNEL/

PAGE_KERNEL_IO is an x86-ism. Though it is used to define the pgprot_t
used for the iomapped region, it itself is just PAGE_KERNEL. On all
other arches, PAGE_KERNEL_IO is undefined so in a general header we must
refrain from using it.

v2: include pgtable for pgprot_combine()

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: linux-mm@kvack.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160823155024.22379-1-chris@chris-wilson.co.uk

drm/i915/skl: Update plane watermarks atomically during plane updates

Thanks to Ville for suggesting this as a potential solution to pipe
underruns on Skylake.

On Skylake all of the registers for configuring planes, including the
registers for configuring their watermarks, are double buffered. New
values written to them won't take effect until said registers are
"armed", which is done by writing to the PLANE_SURF (or in the case of
cursor planes, the CURBASE register) register.

With this in mind, up until now we've been updating watermarks on skl
like this:

  non-modeset {
   - calculate (during atomic check phase)
   - finish_atomic_commit:
     - intel_pre_plane_update:
        - intel_update_watermarks()
     - {vblank happens; new watermarks + old plane values => underrun }
     - drm_atomic_helper_commit_planes_on_crtc:
        - start vblank evasion
        - write new plane registers
        - end vblank evasion
  }

  or

  modeset {
   - calculate (during atomic check phase)
   - finish_atomic_commit:
     - crtc_enable:
        - intel_update_watermarks()
     - {vblank happens; new watermarks + old plane values => underrun }
     - drm_atomic_helper_commit_planes_on_crtc:
        - start vblank evasion
        - write new plane registers
        - end vblank evasion
  }

Now we update watermarks atomically like this:

  non-modeset {
   - calculate (during atomic check phase)
   - finish_atomic_commit:
     - intel_pre_plane_update:
        - intel_update_watermarks() (wm values aren't written yet)
     - drm_atomic_helper_commit_planes_on_crtc:
        - start vblank evasion
        - write new plane registers
        - write new wm values
        - end vblank evasion
  }

  modeset {
   - calculate (during atomic check phase)
   - finish_atomic_commit:
     - crtc_enable:
        - intel_update_watermarks() (actual wm values aren't written
          yet)
     - drm_atomic_helper_commit_planes_on_crtc:
        - start vblank evasion
        - write new plane registers
- write new wm values
        - end vblank evasion
  }

So this patch moves all of the watermark writes into the right place;
inside of the vblank evasion where we update all of the registers for
each plane. While this patch doesn't fix everything, it does allow us to
update the watermark values in the way the hardware expects us to.

Changes since original patch series:
 - Remove mutex_lock/mutex_unlock since they don't do anything and we're
   not touching global state
 - Move skl_write_cursor_wm/skl_write_plane_wm functions into
   intel_pm.c, make externally visible
 - Add skl_write_plane_wm calls to skl_update_plane
 - Fix conditional for for loop in skl_write_plane_wm (level < max_level
   should be level <= max_level)
 - Make diagram in commit more accurate to what's actually happening
 - Add Fixes:

Changes since v1:
 - Use IS_GEN9() instead of IS_SKYLAKE() since these fixes apply to more
   then just Skylake
 - Update description to make it clear this patch doesn't fix everything
 - Check if pipes were actually changed before writing watermarks

Changes since v2:
 - Write PIPE_WM_LINETIME during vblank evasion

Changes since v3:
 - Rebase against new SAGV patch changes

Changes since v4:
 - Add a parameter to choose what skl_wm_values struct to use when
   writing new plane watermarks

Changes since v5:
 - Remove cursor ddb entry write in skl_write_cursor_wm(), defer until
   patch 6
 - Write WM_LINETIME in intel_begin_crtc_commit()

Changes since v6:
 - Remove redundant dirty_pipes check in skl_write_plane_wm (we check
   this in all places where we call this function, and it was supposed
   to have been removed earlier anyway)
 - In i9xx_update_cursor(), use dev_priv->info.gen >= 9 instead of
   IS_GEN9(dev_priv). We do this everywhere else and I'd imagine this
   needs to be done for gen10 as well

Changes since v7:
 - Fix rebase fail (unused variable obj)
 - Make struct skl_wm_values *wm const
 - Fix indenting
 - Use INTEL_GEN() instead of dev_priv->info.gen

Changes since v8:
 - Don't forget calls to skl_write_plane_wm() when disabling planes
 - Use INTEL_GEN(), not INTEL_INFO()->gen in intel_begin_crtc_commit()

Fixes: 2d41c0b59afc ("drm/i915/skl: SKL Watermark Computation")
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Cc: stable@vger.kernel.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471884608-10671-1-git-send-email-cpaul@redhat.com
Link: http://patchwork.freedesktop.org/patch/msgid/1471884608-10671-1-git-send-email-cpaul@redhat.com

drm/i915: Use more atomic state in intel_color.c

crtc_state is already passed around, use it instead of crtc->config.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-16-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_dp to use atomic state

Slightly less straightforward. Some of the drrs calls are done from
workers or from intel_ddi.c, pass along crtc_state when we can,
or crtc->config when we can't.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-15-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_dp_mst to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-14-git-send-email-maarten.lankhorst@linux.intel.com
[mlankhorst: Address bikeshed.]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_lvds to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-13-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[mlankhorst: Small fixup wrt register renames.]

drm/i915: Convert intel_sdvo to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-12-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_dsi to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-11-git-send-email-maarten.lankhorst@linux.intel.com
[mlankhorst: Unbreak bxt_dsi_get_pipe_config]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_dvo to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-10-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Convert intel_crt to use atomic state

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-9-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Remove unused loop from intel_dp_mst_compute_config

Now that conn_state is passed in as argument to compute_config, it's
guaranteed that there is a connector for the argument. The code that
looks for the connector is now dead, and completely unused. Delete it.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-8-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Make encoder->compute_config take the connector state

Some places iterate over connector_state to find the right
connector, pass it along as argument.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-7-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Pass crtc_state and connector_state to encoder functions

This is mostly code churn, with exception of a few places:
- intel_display.c has changes in intel_sanitize_encoder
- intel_ddi.c has intel_ddi_fdi_disable calling intel_ddi_post_disable,
  and required a function change. Also affects intel_display.c
- intel_dp_mst.c passes a NULL crtc_state and conn_state to
  intel_ddi_post_disable for shutting down the real encoder.

  If we would pass conn_state, then conn_state->connector !=
  intel_dig_port->connector and conn_state->best_encoder !=
  to_intel_encoder(intel_dig_port).

  We also shouldn't pass crtc_state, because in that case the
  disabling sequence may potentially be different depending on
  which crtc is disabled last. Nice way to introduce bugs.

No other functional changes are done, diff stat is already huge.
Each encoder type will need to be fixed to use the atomic states
separately.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-6-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Walk over encoders in crtc enable/disable using atomic state.

This cleans up another possible use of the connector list,
encoder->crtc is legacy state and should not be used.

With the atomic state as argument it's easy to find the encoder from
the connector it belongs to.

intel_opregion_notify_encoder is a noop for !HAS_DDI, so it's harmless
to unconditionally include it in encoder enable/disable.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-5-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Remove unused mode_set hook from encoder

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-4-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Pass atomic state to crtc enable/disable functions

This is required for supporting nonblocking modesets. Iterating over
the connector list will no longer be allowed when we don't hold
connection_mutex, so we have to use the atomic state.

Fix disable_noatomic by populating the minimal state required to
disable a connector.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-3-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: handle DP_MST correctly in bxt_get_dpll

No idea if it supports it, but this is the minimum required from get_dpll.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470755054-32699-2-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Take forcewake once for the entire GMBUS transaction

As we do many register reads within a very short period of time, hold
the GMBUS powerwell from start to finish.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819164503.17845-1-chris@chris-wilson.co.uk
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>

drm/i915: Fix nesting of filelist_mutex vs struct_mutex in i915_ppgtt_info

An unlikely ABBA deadlock in debugfs that no one has reported.

[  284.922349] ======================================================
[  284.922355] [ INFO: possible circular locking dependency detected ]
[  284.922361] 4.8.0-rc2+ #430 Tainted: G        W
[  284.922366] -------------------------------------------------------
[  284.922371] cat/1197 is trying to acquire lock:
[  284.922376]  (&dev->filelist_mutex){+.+...}, at: [<ffffffffa0055ba2>] i915_ppgtt_info+0x82/0x390 [i915]
[  284.922423]
[  284.922423] but task is already holding lock:
[  284.922429]  (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0055b55>] i915_ppgtt_info+0x35/0x390 [i915]
[  284.922465]
[  284.922465] which lock already depends on the new lock.
[  284.922465]
[  284.922471]
[  284.922471] the existing dependency chain (in reverse order) is:
[  284.922477]
-> #1 (&dev->struct_mutex){+.+.+.}:
[  284.922493]        [<ffffffff81087710>] lock_acquire+0x60/0x80
[  284.922505]        [<ffffffff8143e96f>] mutex_lock_nested+0x5f/0x360
[  284.922520]        [<ffffffffa004f877>] print_context_stats+0x37/0xf0 [i915]
[  284.922549]        [<ffffffffa00535f5>] i915_gem_object_info+0x265/0x490 [i915]
[  284.922581]        [<ffffffff81144491>] seq_read+0xe1/0x3b0
[  284.922592]        [<ffffffff811f77b3>] full_proxy_read+0x83/0xb0
[  284.922604]        [<ffffffff8111ba03>] __vfs_read+0x23/0x110
[  284.922616]        [<ffffffff8111c9b9>] vfs_read+0x89/0x110
[  284.922626]        [<ffffffff8111dbf4>] SyS_read+0x44/0xa0
[  284.922636]        [<ffffffff81442be9>] entry_SYSCALL_64_fastpath+0x1c/0xac
[  284.922648]
-> #0 (&dev->filelist_mutex){+.+...}:
[  284.922667]        [<ffffffff810871fc>] __lock_acquire+0x10fc/0x1270
[  284.922678]        [<ffffffff81087710>] lock_acquire+0x60/0x80
[  284.922689]        [<ffffffff8143e96f>] mutex_lock_nested+0x5f/0x360
[  284.922701]        [<ffffffffa0055ba2>] i915_ppgtt_info+0x82/0x390 [i915]
[  284.922729]        [<ffffffff81144491>] seq_read+0xe1/0x3b0
[  284.922739]        [<ffffffff811f77b3>] full_proxy_read+0x83/0xb0
[  284.922750]        [<ffffffff8111ba03>] __vfs_read+0x23/0x110
[  284.922761]        [<ffffffff8111c9b9>] vfs_read+0x89/0x110
[  284.922771]        [<ffffffff8111dbf4>] SyS_read+0x44/0xa0
[  284.922781]        [<ffffffff81442be9>] entry_SYSCALL_64_fastpath+0x1c/0xac
[  284.922793]
[  284.922793] other info that might help us debug this:
[  284.922793]
[  284.922809]  Possible unsafe locking scenario:
[  284.922809]
[  284.922818]        CPU0                    CPU1
[  284.922825]        ----                    ----
[  284.922831]   lock(&dev->struct_mutex);
[  284.922842]                                lock(&dev->filelist_mutex);
[  284.922854]                                lock(&dev->struct_mutex);
[  284.922865]   lock(&dev->filelist_mutex);
[  284.922875]
[  284.922875]  *** DEADLOCK ***
[  284.922875]
[  284.922888] 3 locks held by cat/1197:
[  284.922895]  #0:  (debugfs_srcu){......}, at: [<ffffffff811f7730>] full_proxy_read+0x0/0xb0
[  284.922919]  #1:  (&p->lock){+.+.+.}, at: [<ffffffff811443e8>] seq_read+0x38/0x3b0
[  284.922942]  #2:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0055b55>] i915_ppgtt_info+0x35/0x390 [i915]
[  284.922983]

Fixes: 1d2ac403ae3b ("drm: Protect dev->filelist with its own mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822132820.21725-1-chris@chris-wilson.co.uk

drm/i915: Ignore stuck requests when considering hangs

If the engine isn't being retired (worker starvation?) then it is
possible for us to repeatedly observe that between consecutive
hangchecks the seqno on the ring to be the same and there remain
unretired requests. Ignore these completely and only regard the engine
as busy for the purpose of hang detection (not stall detection) if there
are outstanding breadcrumbs.

In recent history we have looked at using both the request and seqno as
indication of activity on the engine, but that was reduced to just
inspecting seqno in commit cffa781e5907 ("drm/i915: Simplify check for
idleness in hangcheck"). However, in commit dcff85c8443e ("drm/i915:
Enable i915_gem_wait_for_idle() without holding struct_mutex"), I made
the decision to use the new common lockless function, under the
assumption that request retirement was more frequent than hangcheck and
so we would not have a stuck busy check. The flaw there was in
forgetting that we accumulate the hang score, and so successive checks
seeing a stuck request, albeit with the GPU advancing elsewhere and so
not necessary the same stuck request, would eventually trigger the hang.

Fixes: dcff85c8443e ("drm/i915: Enable i915_gem_wait_for_idle()...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160820145408.32180-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915: Allow DMA pagetables to use highmem

As we never need to directly access the pages we allocate for scratch and
the pagetables, and always remap them into the GTT through the dma
remapper, we do not need to limit the allocations to lowmem i.e. we can
pass in the __GFP_HIGHMEM flag to the page allocation.

For backwards compatibility, e.g. certain old GPUs not liking highmem
for certain functions that may be accidentally mapped to the scratch
page by userspace, keep the GMCH probe as only allocating from DMA32.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822074431.26872-3-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Embed the scratch page struct into each VM

As the scratch page is no longer shared between all VM, and each has
their own, forgo the small allocation and simply embed the scratch page
struct into the i915_address_space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822074431.26872-2-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915: debugfs spring cleaning

Just like with sysfs, we do some major overhaul.

Pass dev_priv instead of dev to all feature macros (IS_, HAS_,
INTEL_, etc.). This has the side effect that a bunch of functions
now get dev_priv passed instead of dev.

All calls to INTEL_INFO()->gen have been replaced with
INTEL_GEN().

We want access to to_i915(node->minor->dev) in a lot of places,
so add the node_to_i915() helper to accommodate for this.

Finally, we have quite a few cases where we get a void * pointer,
and need to cast it to drm_device *, only to run to_i915() on it.
Add cast_to_i915() to do this.

v2: Don't introduce extra dev (Chris)

v3: Make pipe_crc_info have a pointer to drm_i915_private instead of
    drm_device. This saves a bit of space, since we never use
    drm_device anywhere in these functions.

    Also some minor fixup that I missed in the previous version.

v4: Changed the code a bit so that dev_priv is passed directly
    to various functions, thus removing the need for the
    cast_to_i915() helper. Also did some additional cleanup.

v5: Additional cleanup of newly introduced changes.

v6: Rebase again because of conflict.

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822105931.pcbe2lpsgzckzboa@boom
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: pdev cleanup

In an effort to simplify things for a future push of dev_priv instead
of dev wherever possible, always take pdev via dev_priv where
feasible, eliminating the direct access from dev. Right now this
only eliminates a few cases of dev, but it also obviates that we pass
dev into a lot of functions where dev_priv would be the more obvious
choice.

v2: Fixed one more place missing in the previous patch set

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822103245.24069-5-david.weinehall@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: i915_sysfs.c cleanup

Various cleanup for i915_sysfs.c; we now use dev_priv whenever
possible. The kdev_to_drm_minor() helper function has been
replaced by one that converts from struct device *
to struct drm_i915_private *.

We already have a seemingly identical helper (kdev_to_i915())
in i915_drv.h. But that one cannot be used here.
Unlike the version in i915_drv.h, this helper
reaches i915 through drm_minor.

v2: Rename kdev_to_i915_dm() to kdev_minor_to_i915() (Chris)

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822103245.24069-4-david.weinehall@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: consistent struct device naming

We currently have a mix of struct device *device, struct device *kdev,
and struct device *dev (the latter forcing us to refer to
struct drm_device as something else than the normal dev).

To simplify things, always use kdev when referring to struct device.

v2: Replace the dev_to_drm_minor() macro with the inline function
    kdev_to_drm_minor().

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822103245.24069-3-david.weinehall@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: cosmetic fixes to i915_drv.h

Fix minor whitespace issues plus a typo.

Signed-off-by: David Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822103245.24069-2-david.weinehall@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Fix botched merge that downgrades CSR versions.

Merge commit 5e580523d9128a4d8 reverts the version bumping parts of
commit 4aa7fb9c3c4fa0. Bump the versions again and request the specific
firmware version.

The currently recommended versions are: SKL 1.26, KBL 1.01 and BXT 1.07.

Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97242
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 5e580523d912 ("Backmerge tag 'v4.7' into drm-next")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471266567-22443-1-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

drm/i915/skl: Ensure pipes with changed wms get added to the state

If we're enabling a pipe, we'll need to modify the watermarks on all
active planes. Since those planes won't be added to the state on
their own, we need to add them ourselves.

Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Cc: stable@vger.kernel.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-6-git-send-email-cpaul@redhat.com

drm/i915/gen9: Only copy WM results for changed pipes to skl_hw

When we write watermark values to the hardware, those values are stored
in dev_priv->wm.skl_hw.  However with recent watermark changes, the
results structure we're copying from only contains valid watermark and
DDB values for the pipes that are actually changing; the values for
other pipes remain 0.  Thus a blind copy of the entire skl_wm_values
structure will clobber the values for unchanged pipes...we need to be
more selective and only copy over the values for the changing pipes.

This mistake was hidden until recently due to another bug that caused us
to erroneously re-calculate watermarks for all active pipes rather than
changing pipes.  Only when that bug was fixed was the impact of this bug
discovered (e.g., modesets failing with "Requested display configuration
exceeds system watermark limitations" messages and leaving watermarks
non-functional, even ones initiated by intel_fbdev_restore_mode).

Changes since v1:
 - Add a function for copying a pipe's wm values
   (skl_copy_wm_for_pipe()) so we can reuse this later

Fixes: 734fa01f3a17 ("drm/i915/gen9: Calculate watermarks during atomic 'check' (v2)")
Fixes: 9b6130227495 ("drm/i915/gen9: Re-allocate DDB only for changed pipes")
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Cc: stable@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-4-git-send-email-cpaul@redhat.com

drm/i915/skl: Add support for the SAGV, fix underrun hangs

Since the watermark calculations for Skylake are still broken, we're apt
to hitting underruns very easily under multi-monitor configurations.
While it would be lovely if this was fixed, it's not. Another problem
that's been coming from this however, is the mysterious issue of
underruns causing full system hangs. An easy way to reproduce this with
a skylake system:

- Get a laptop with a skylake GPU, and hook up two external monitors to
  it
- Move the cursor from the built-in LCD to one of the external displays
  as quickly as you can
- You'll get a few pipe underruns, and eventually the entire system will
  just freeze.

After doing a lot of investigation and reading through the bspec, I
found the existence of the SAGV, which is responsible for adjusting the
system agent voltage and clock frequencies depending on how much power
we need. According to the bspec:

"The display engine access to system memory is blocked during the
 adjustment time. SAGV defaults to enabled. Software must use the
 GT-driver pcode mailbox to disable SAGV when the display engine is not
 able to tolerate the blocking time."

The rest of the bspec goes on to explain that software can simply leave
the SAGV enabled, and disable it when we use interlaced pipes/have more
then one pipe active.

Sure enough, with this patchset the system hangs resulting from pipe
underruns on Skylake have completely vanished on my T460s. Additionally,
the bspec mentions turning off the SAGV with more then one pipe enabled
as a workaround for display underruns. While this patch doesn't entirely
fix that, it looks like it does improve the situation a little bit so
it's likely this is going to be required to make watermarks on Skylake
fully functional.

This will still need additional work in the future: we shouldn't be
enabling the SAGV if any of the currently enabled planes can't enable WM
levels that introduce latencies >= 30 µs.

Changes since v11:
 - Add skl_can_enable_sagv()
 - Make sure we don't enable SAGV when not all planes can enable
   watermarks >= the SAGV engine block time. I was originally going to
   save this for later, but I recently managed to run into a machine
   that was having problems with a single pipe configuration + SAGV.
 - Make comparisons to I915_SKL_SAGV_NOT_CONTROLLED explicit
 - Change I915_SAGV_DYNAMIC_FREQ to I915_SAGV_ENABLE
 - Move printks outside of mutexes
 - Don't print error messages twice
Changes since v10:
 - Apparently sandybridge_pcode_read actually writes values and reads
   them back, despite it's misleading function name. This means we've
   been doing this mostly wrong and have been writing garbage to the
   SAGV control. Because of this, we no longer attempt to read the SAGV
   status during initialization (since there are no helpers for this).
 - mlankhorst noticed that this patch was breaking on some very early
   pre-release Skylake machines, which apparently don't allow you to
   disable the SAGV. To prevent machines from failing tests due to SAGV
   errors, if the first time we try to control the SAGV results in the
   mailbox indicating an invalid command, we just disable future attempts
   to control the SAGV state by setting dev_priv->skl_sagv_status to
   I915_SKL_SAGV_NOT_CONTROLLED and make a note of it in dmesg.
 - Move mutex_unlock() a little higher in skl_enable_sagv(). This
   doesn't actually fix anything, but lets us release the lock a little
   sooner since we're finished with it.
Changes since v9:
 - Only enable/disable sagv on Skylake
Changes since v8:
 - Add intel_state->modeset guard to the conditional for
   skl_enable_sagv()
Changes since v7:
 - Remove GEN9_SAGV_LOW_FREQ, replace with GEN9_SAGV_IS_ENABLED (that's
   all we use it for anyway)
 - Use GEN9_SAGV_IS_ENABLED instead of 0x1 for clarification
 - Fix a styling error that snuck past me
Changes since v6:
 - Protect skl_enable_sagv() with intel_state->modeset conditional in
   intel_atomic_commit_tail()
Changes since v5:
 - Don't use is_power_of_2. Makes things confusing
 - Don't use the old state to figure out whether or not to
   enable/disable the sagv, use the new one
 - Split the loop in skl_disable_sagv into it's own function
 - Move skl_sagv_enable/disable() calls into intel_atomic_commit_tail()
Changes since v4:
 - Use is_power_of_2 against active_crtcs to check whether we have > 1
   pipe enabled
 - Fix skl_sagv_get_hw_state(): (temp & 0x1) indicates disabled, 0x0
   enabled
 - Call skl_sagv_enable/disable() from pre/post-plane updates
Changes since v3:
 - Use time_before() to compare timeout to jiffies
Changes since v2:
 - Really apply minor style nitpicks to patch this time
Changes since v1:
 - Added comments about this probably being one of the requirements to
   fixing Skylake's watermark issues
 - Minor style nitpicks from Matt Roper
 - Disable these functions on Broxton, since it doesn't have an SAGV

Signed-off-by: Lyude <cpaul@redhat.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-3-git-send-email-cpaul@redhat.com
[mlankhorst: ENOSYS -> ENXIO, whitespace fixes]

drm/i915/gen6+: Interpret mailbox error flags

In order to add proper support for the SAGV, we need to be able to know
what the cause of a failure to change the SAGV through the pcode mailbox
was. The reasoning for this is that some very early pre-release Skylake
machines don't actually allow you to control the SAGV on them, and
indicate an invalid mailbox command was sent.

This also might come in handy in the future for debugging.

Changes since v1:
 - Add functions for interpreting gen6 mailbox error codes along with
   gen7+ error codes, and actually interpret those codes properly
 - Renamed patch to reflect new behavior

Signed-off-by: Lyude <cpaul@redhat.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-2-git-send-email-cpaul@redhat.com
[mlankhorst: -ENOSYS -> -ENXIO for checkpatch]

drm/i915: Call intel_fbc_pre_update() after pinning the new pageflip

intel_fbc_pre_update() depends upon the new state being already pinned
in place in the Global GTT (primarily for both fencing which wants both
an offset and a fence register, if assigned). This requires the call to
intel_fbc_pre_update() be after intel_pin_and_fence_fb() - but commit
e8216e502aca ("drm/i915/fbc: call intel_fbc_pre_update earlier during
page flips") moved the code way too much up in its attempt to call it
before the page flip.

v2 (from Paulo):
 - Point the original bad commit.
 - Add a comment to maybe prevent further regressions.

Fixes: e8216e502aca ("drm/i915/fbc: call intel_fbc_pre_update earlier...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1471462904-842-1-git-send-email-paulo.r.zanoni@intel.com
Cc: stable@vger.kernel.org

drm/i915: Ensure consistent control flow __i915_gem_active_get_rcu

This issue here is (I think) purely theoretical, since a compiler
would need to be especially foolish to recompute the value of
i915_gem_request_completed right after it was already used. Hence the
additional barrier() is also not really a restriction.

But I believe this to be at least permissible, and since our rcu
trickery is a beast it's worth to annotate all the corner cases.
Chris proposed to instead just wrap a READ_ONCE around
request->fence.seqno in i915_gem_request_completed. But that has a
measurable impact on code size, and everywhere we hold a full
reference to the underlying request it's also not needed. And
personally I'd like to have just enough barriers and locking needed
for correctness, but not more - it makes it much easier in the future
to understand what's going on.

Since the busy ioctl has now fully embraced it's races there's no
point annotating it there too. We really only need it in
active_get_rcu, since that function _must_ deliver a correct snapshot
of the active fences (and not chase something else).

v2: Polish the comment a bit more (Chris).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1471856122-466-1-git-send-email-daniel.vetter@ffwll.ch

drm/i915: Stop marking the unaccessible scratch page as UC

Since by design, if not entirely by practice, nothing is allowed to
access the scratch page we use to background fill the VM, then we do not
need to ensure that it is coherent between the CPU and GPU.
set_pages_uc() does a stop_machine() after changing the PAT, and that
significantly impacts upon context creation throughput.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822074431.26872-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Restore debugfs/i915_gem_gtt back to its former glory

The passed in flag that distinguishes i915_gem_pin_display from
i915_gem_gtt is from node->info_ent->data not the data function
parameter.

Fixes: 6da8482936c7 ("drm/i915: Focus debugfs/i915_gem_pinned to show...")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819115625.17688-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Update DRIVER_DATE to 20160822

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Use remap_io_mapping() to prefault all PTE in a single pass

Very old numbers indicate this is a 66% improvement when remapping the
entire object for fence contention - due to the elimination of
track_pfn_insert and its strcmp.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Testcase: igt/gem_fence_upload/performance
Testcase: igt/gem_mmap_gtt
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-6-chris@chris-wilson.co.uk

drm/i915: Embed the io-mapping struct inside drm_i915_private

As io_mapping.h now always allocates the struct, we can avoid that
allocation and extra pointer dance by embedding the struct inside
drm_i915_private

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-5-chris@chris-wilson.co.uk

io-mapping: Always create a struct to hold metadata about the io-mapping

Currently, we only allocate a structure to hold metadata if we need to
allocate an ioremap for every access, such as on x86-32. However, it
would be useful to store basic information about the io-mapping, such as
its page protection, on all platforms.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: linux-mm@kvack.org
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-4-chris@chris-wilson.co.uk

drm/i915/fbc: Allow on unfenced surfaces, for recent gen

Only fbc1 is tied to using a fence. Later iterations of fbc are more
flexible and allow operation on unfenced frontbuffers.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-3-chris@chris-wilson.co.uk

drm/i915/fbc: Don't set an illegal fence if unfenced

If the frontbuffer doesn't have an associated fence, it will have a
fence reg of -1. If we attempt to OR in this register into the FBC
control register we end up setting all control bits, oops!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Reviwed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-2-chris@chris-wilson.co.uk

drm/i915: Flush delayed fence releases after reset

What I never hit in testing, but Mika immediately did, was a GPU hang
with a pending fence release (where a tiled object has been changed by
the user to be untiled, and the update has not yet been committed to the
fence register). As the stride/tiling is 0, this causes a divide-by-zero
error when trying to write the new fence parameters:

[   28.784518] drm/i915: Resetting chip after gpu hang
[   28.784551] divide error: 0000 [#1] PREEMPT SMP
[   28.784565] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat mxm_wmi x86_pkg_temp_thermal snd_hda_codec_hdmi kvm irqbypass snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec serio_raw snd_hwdep snd_hda_core snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_timer snd_seq_device snd soundcore mac_hid wmi efivarfs autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid0 multipath linear psmouse e1000e ptp pps_core nvme nvme_core i915 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm video
[   28.784738] CPU: 0 PID: 1692 Comm: kworker/0:2 Not tainted 4.8.0-rc2+ #895
[   28.784752] Hardware name: System manufacturer System Product Name/Z170M-PLUS, BIOS 1803 05/09/2016
[   28.784786] Workqueue: events_long i915_hangcheck_elapsed [i915]
[   28.784814] task: ffff923c18f59d40 task.stack: ffff923c1b7e4000
[   28.784827] RIP: 0010:[<ffffffffc0475b5f>]  [<ffffffffc0475b5f>] fence_write+0x9f/0x3b0 [i915]
[   28.784854] RSP: 0018:ffff923c1b7e7b30  EFLAGS: 00010246
[   28.784866] RAX: 00000000008ca000 RBX: ffff923c18540000 RCX: 0000000000000020
[   28.784880] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000596d000
[   28.784894] RBP: ffff923c1b7e7b68 R08: 0000000000000000 R09: 0000000000000000
[   28.784908] R10: 0000000000000000 R11: 00000000008ca000 R12: ffff923c1ef9d600
[   28.784921] R13: 0000000000100040 R14: 0000000000100044 R15: ffff923c18549908
[   28.784935] FS:  0000000000000000(0000) GS:ffff923c36c00000(0000) knlGS:0000000000000000
[   28.784951] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.784962] CR2: 00007f193373c893 CR3: 0000000419c78000 CR4: 00000000003406f0
[   28.784976] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   28.784990] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   28.785004] Stack:
[   28.785009]  000000000596c03b ffff923c1b7e7b68 ffff923c18549938 0000000000000009
[   28.785026]  ffff923c18540000 ffff923c18549280 ffff923c18547ce8 ffff923c1b7e7b90
[   28.785044]  ffffffffc04761f9 ffff923c18540000 ffff923c18547d00 ffff923c18548ff8
[   28.785062] Call Trace:
[   28.785078]  [<ffffffffc04761f9>] i915_gem_restore_fences+0x39/0x50 [i915]
[   28.785102]  [<ffffffffc047fe89>] i915_gem_reset+0x179/0x300 [i915]

Reported-by: Mika Kuoppala <mika.kuoppala@intel.com>
Fixes: 49ef5294cda2 ("drm/i915: Move fence tracking from object to vma")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-1-chris@chris-wilson.co.uk

drm/i915: Reattach comment, complete type specification

In the recent patch
bc3d674 drm/i915: Allow userspace to request no-error-capture upon ...
the final version moved the flags and the associated #defines around
so they were adjacent; unfortunately, they ended up between a comment
and the thing (hw_id) to which the comment applies :(

So this patch reshuffles the comment and subject back together.

Also, as we're touching 'hw_id', let's change it from just 'unsigned'
to a fully-specified 'unsigned int', because some code checking tools
(including checkpatch) object to plain 'unsigned'.

Fixes: bc3d674462e5 ("drm/i915: Allow userspace to request no-error-capture...")
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1471616622-6919-1-git-send-email-david.s.gordon@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915/cmdparser: Accelerate copies from WC memory

If we need to use clflush to prepare our batch for reads from memory, we
can bypass the cache instead by using non-temporal copies.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-39-chris@chris-wilson.co.uk

drm/i915/cmdparser: Use binary search for faster register lookup

A significant proportion of the cmdparsing time for some batches is the
cost to find the register in the mmiotable. We ensure that those tables
are in ascending order such that we could do a binary search if it was
ever merited. It is.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-38-chris@chris-wilson.co.uk

drm/i915/cmdparser: Check for SKIP descriptors first

If the command descriptor says to skip it, ignore checking for anyother
other conflict.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-37-chris@chris-wilson.co.uk

drm/i915/cmdparser: Compare against the previous command descriptor

On the blitter (and in test code), we see long sequences of repeated
commands, e.g. XY_PIXEL_BLT, XY_SCANLINE_BLT, or XY_SRC_COPY. For these,
we can skip the hashtable lookup by remembering the previous command
descriptor and doing a straightforward compare of the command header.
The corollary is that we need to do one extra comparison before lookup
up new commands.

v2: Less magic mask (ok, it is still magic, but now you cannot see!)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-36-chris@chris-wilson.co.uk

drm/i915/cmdparser: Improve hash function

The existing code's hashfunction is very suboptimal (most 3D commands
use the same bucket degrading the hash to a long list). The code even
acknowledge that the issue was known and the fix simple:

/*
 * If we attempt to generate a perfect hash, we should be able to look at bits
 * 31:29 of a command from a batch buffer and use the full mask for that
 * client. The existing INSTR_CLIENT_MASK/SHIFT defines can be used for this.
 */

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-35-chris@chris-wilson.co.uk

drm/i915/cmdparser: Only cache the dst vmap

For simplicity, we want to continue using a contiguous mapping of the
command buffer, but we can reduce the number of vmappings we hold by
switching over to a page-by-page copy from the user batch buffer to the
shadow. The cost for saving one linear mapping is about 5% in trivial
workloads - which is more or less the overhead in calling kmap_atomic().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-34-chris@chris-wilson.co.uk

drm/i915/cmdparser: Use cached vmappings

The single largest factor in the overhead of parsing the commands is the
setup of the virtual mapping to provide a continuous block for the batch
buffer. If we keep those vmappings around (against the better judgement
of mm/vmalloc.c, which we offset by handwaving and looking suggestively
at the shrinker) we can dramatically improve the performance of the
parser for small batches (such as media workloads). Furthermore, we can
use the prepare shmem read/write functions to determine  how best we
need to clflush the range (rather than every page of the object).

The impact of caching both src/dst vmaps is +80% on ivb and +140% on byt
for the throughput on small batches. (Caching just the dst vmap and
iterating over the src, doing a page by page copy is roughly 5% slower
on both platforms. That may be an acceptable trade-off to eliminate one
cached vmapping, and we may be able to reduce the per-page copying overhead
further.) For *this* simple test case, the cmdparser is now within a
factor of 2 of ideal performance.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-33-chris@chris-wilson.co.uk

drm/i915/cmdparser: Add the TIMESTAMP register for the other engines

Since I have been using the BCS_TIMESTAMP to measure latency of
execution upon the blitter ring, allow regular userspace to also read
from that register. They are already allowed RCS_TIMESTAMP!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-32-chris@chris-wilson.co.uk

drm/i915/cmdparser: Make initialisation failure non-fatal

If the developer adds a register in the wrong order, we BUG during boot.
That makes development and testing very difficult. Let's be a bit more
friendly and disable the command parser with a big warning if the tables
are invalid.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-31-chris@chris-wilson.co.uk

drm/i915: Stop discarding GTT cache-domain on unbind vma

Since commit 43566dedde54 ("drm/i915: Broaden application of
set-domain(GTT)") we allowed objects to be in the GTT domain, but unbound.
Therefore removing the GTT cache domain when removing the GGTT vma is no
longer semantically correct.

An unfortunate side-effect is we lose the wondrously named
i915_gem_object_finish_gtt(), not to be confused with
i915_gem_gtt_finish_object()!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Akash Goel <akash.goel@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-30-chris@chris-wilson.co.uk

drm/i915: Bump the inactive tracking for all VMA accessed

We track the LRU access for eviction and bump the last access for the
user GGTT on set-to-gtt. When we do so we need to not only bump the
primary GGTT VMA but all partials as well. Similarly we want to
bump the last access tracking for when unpinning an object from the
scanout so that they do not get promptly evicted and hopefully remain
available for reuse on the next frame.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-29-chris@chris-wilson.co.uk

drm/i915: Track display alignment on VMA

When using the aliasing ppgtt and pageflipping with the shrinker/eviction
active, we note that we often have to rebind the backbuffer before
flipping onto the scanout because it has an invalid alignment. If we
store the worst-case alignment required for a VMA, we can avoid having
to rebind at critical junctures.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-28-chris@chris-wilson.co.uk

drm/i915: Fallback to using unmappable memory for scanout

The existing ABI says that scanouts are pinned into the mappable region
so that legacy clients (e.g. old Xorg or plymouthd) can write directly
into the scanout through a GTT mapping. However if the surface does not
fit into the mappable region, we are better off just trying to fit it
anywhere and hoping for the best. (Any userspace that is capable of
using ginormous scanouts is also likely not to rely on pure GTT
updates.) With the partial vma fault support, we are no longer
restricted to only using scanouts that we can pin (though it is still
preferred for performance reasons and for powersaving features like
FBC).

v2: Skip fence pinning when not mappable.
v3: Add a comment to explain the possible ramifications of not being
    able to use fences for unmappable scanouts.
v4: Rebase to skip over some local patches
v5: Rebase to defer until after we have unmappable GTT fault support

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Deepak S <deepak.s@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-27-chris@chris-wilson.co.uk

drm/i915: Choose not to evict faultable objects from the GGTT

Often times we do not want to evict mapped objects from the GGTT as
these are quite expensive to teardown and frequently reused (causing an
equally, if not more so, expensive setup). In particular, when faulting
in a new object we want to avoid evicting an active object, or else we
may trigger a page-fault-of-doom as we ping-pong between evicting two
objects.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-26-chris@chris-wilson.co.uk

drm/i915: Drop ORIGIN_GTT for untracked GTT writes

If FBC is set on a framebuffer that is unmapped, all GTT faults will be
from a partial mapping. Writes by the user through the partial VMA are
then untracked by the FBC and so we must use the ORIGIN_CPU when flushing
the I915_GEM_DOMAIN_GTT.

v2: Keep ORIGIN_CPU for set-to-domain(.write=CPU)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-25-chris@chris-wilson.co.uk

drm/i915: Convert partial ggtt vma to full ggtt if it spans the entire object

If we want to create a partial vma from a chunk that is the same size as
the object, create a normal ggtt vma instead. The benefit is that it
will match future requests for the normal ggtt.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-24-chris@chris-wilson.co.uk

drm/i915: Fix partial GGTT faulting

We want to always use the partial VMA as a fallback for a failure to
bind the object into the GGTT. This extends the support partial objects
in the GGTT to cover everything, not just objects too large.

v2: Call the partial view, view not partial.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-23-chris@chris-wilson.co.uk

drm/i915: Choose partial chunksize based on tile row size

In order to support setting up fences for partial mappings of an object,
we have to align those mappings with the fence. The minimum chunksize we
choose is at least the size of a single tile row.

v2: Make minimum chunk size a define for later use

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-22-chris@chris-wilson.co.uk

drm/i915: Move fence tracking from object to vma

In order to handle tiled partial GTT mmappings, we need to associate the
fence with an individual vma.

v2: A couple of silly drops replaced spotted by Joonas

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-21-chris@chris-wilson.co.uk

drm/i915: Rename fence.lru_list to link

Our current practice is to only name the actual list (here
dev_priv->fence_list) using "list", and elements upon that list are
referred to as "link". Further, the lru nature is of the list and not of
the node and including in the name does not disambiguate the link from
anything else.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-20-chris@chris-wilson.co.uk

drm/i915/userptr: Make gup errors stickier

Keep any error reported by the gup_worker until we are notified that the
arena has changed (via the mmu-notifier). This has the importance of
making two consecutive calls to i915_gem_object_get_pages() reporting
the same error, and curtailing a loop of detecting a fault and requeueing
a gup_worker.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-19-chris@chris-wilson.co.uk

drm/i915: Allocate rings from stolen

If we have stolen available, make use of it for ringbuffer allocation.
Previously this was restricted to !llc platforms, as writing to stolen
requires a GGTT mapping - but now that we have partial mappable support,
the mappable aperture isn't quite so precious so we can use it more
freely and ringbuffers are a good user for the otherwise wasted stolen.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-18-chris@chris-wilson.co.uk

drm/i915: Allow ringbuffers to be bound anywhere

Now that we have WC vmapping available, we can bind our rings anywhere
in the GGTT and do not need to restrict them to the mappable region.
Except for stolen objects, for which direct access is verbatim and we
must use the mappable aperture.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-17-chris@chris-wilson.co.uk

drm/i915: Move map-and-fenceable tracking to the VMA

By moving map-and-fenceable tracking from the object to the VMA, we gain
fine-grained tracking and the ability to track individual fences on the VMA
(subsequent patch).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-16-chris@chris-wilson.co.uk

drm/i915: Disallow direct CPU access to stolen pages for relocations

As we cannot access the backing pages behind stolen objects, we should
not attempt to do so for relocations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-15-chris@chris-wilson.co.uk

drm/i915: Fallback to single page GTT mmappings for relocations

If we cannot pin the entire object into the mappable region of the GTT,
try to pin a single page instead. This is much more likely to succeed,
and prevents us falling back to the clflush slow path.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-14-chris@chris-wilson.co.uk

drm/i915: Refactor execbuffer relocation writing

With the introduction of the reloc page cache, we are just one step away
from refactoring the relocation write functions into one. Not only does
it tidy the code (slightly), but it greatly simplifies the control logic
much to gcc's satisfaction.

v2: Add selftests to document the relationship between the clflush
flags, the KMAP bit and packing into the page-aligned pointer.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-13-chris@chris-wilson.co.uk

drm/i915: Tidy up flush cpu/gtt write domains

Since we know the write domain, we can drop the local variable and make
the code look a tiny bit simpler.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-12-chris@chris-wilson.co.uk

drm/i915: Pin the pages first in shmem prepare read/write

There is an improbable, but not impossible, case that if we leave the
pages unpin as we operate on the object, then somebody via the shrinker
may steal the lock (which lock? right now, it is struct_mutex, THE lock)
and change the cache domains after we have already inspected them.

(Whilst here, avail ourselves of the opportunity to take a couple of
steps to make the two functions look more similar.)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-11-chris@chris-wilson.co.uk

drm/i915: Wait for writes through the GTT to land before reading back

If we quickly switch from writing through the GTT to a read of the
physical page directly with the CPU (e.g. performing relocations through
the GTT and then running the command parser), we can observe that the
writes are not visible to the CPU. It is not a coherency problem, as
extensive investigations with clflush have demonstrated, but a mere
timing issue - we have to wait for the GTT to complete it's write before
we start our read from the CPU.

The issue can be illustrated in userspace with:

gtt = gem_mmap__gtt(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
cpu = gem_mmap__cpu(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
gem_set_domain(fd, handle, I915_GEM_DOMAIN_GTT, I915_GEM_DOMAIN_GTT);

for (i = 0; i < OBJECT_SIZE / 64; i++) {
int x = 16*i + (i%16);
gtt[x] = i;
clflush(&cpu[x], sizeof(cpu[x]));
assert(cpu[x] == i);
}

Experimenting with that shows that this behaviour is indeed limited to
recent Atom-class hardware.

Testcase: igt/gem_exec_flush/basic-batch-default-cmd #byt
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-10-chris@chris-wilson.co.uk

drm/i915: Before accessing an object via the cpu, flush GTT writes

If we want to read the pages directly via the CPU, we have to be sure
that we have to flush the writes via the GTT (as the CPU can not see
the address aliasing).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-9-chris@chris-wilson.co.uk

drm/i915: Extract i915_gem_obj_prepare_shmem_write()

This is a companion to i915_gem_obj_prepare_shmem_read() that prepares
the backing storage for direct writes. It first serialises with the GPU,
pins the backing storage and then indicates what clfushes are required in
order for the writes to be coherent.

Whilst here, fix support for ancient CPUs without clflush for which we
cannot do the GTT+clflush tricks.

v2: Add i915_gem_obj_finish_shmem_access() for symmetry

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-8-chris@chris-wilson.co.uk

drm/i915: Cache kmap between relocations

When doing relocations, we have to obtain a mapping to the page
containing the target address. This is either a kmap or iomap depending
on GPU and its cache coherency. Neighbouring relocation entries are
typically within the same page and so we can cache our kmapping between
them and avoid those pesky TLB flushes.

Note that there is some sleight-of-hand in how the slow relocate works
as the reloc_entry_cache implies pagefaults disabled (as we are inside a
kmap_atomic section). However, the slow relocate code is meant to be the
fallback from the atomic fast path failing. Fortunately it works as we
already have performed the copy_from_user for the relocation array (no
more pagefaults there) and the kmap_atomic cache is enabled after we
have waited upon an active buffer (so no more sleeping in atomic).
Magic!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-7-chris@chris-wilson.co.uk

drm/i915: Fallback to single page pwrite/pread if unable to release fence

If we cannot release the fence (for example if someone is inexplicably
trying to write into a tiled framebuffer that is currently pinned to the
display! *cough* kms_frontbuffer_tracking *cough*) fallback to using the
page-by-page pwrite/pread interface, rather than fail the syscall
entirely.

Since this is triggerable by the user (along pwrite) we have to remove
the WARN_ON(fence->pin_count).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-6-chris@chris-wilson.co.uk

drm/i915: Mark up the GTT flush following WC writes as ORIGIN_CPU

Similarly to invalidating beforehand, if the object is mmapped via
I915_MMAP_WC we cannot track writes through the I915_GEM_DOMAIN_GTT. At
the conclusion of the write, i915_gem_object_flush_gtt_writes() we also
need to treat the origin carefully in case it may have been untracked.

See also commit aeecc9696aa0 ("drm/i915: use ORIGIN_CPU for frontbuffer
invalidation on WC mmaps").

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-5-chris@chris-wilson.co.uk

drm/i915: Use ORIGIN_CPU for fb invalidation from pwrite

As pwrite does not use the fence for its GTT access, and may even go
through a secondary interface avoiding the main VMA, we cannot treat the
write as automatically invalidated by the hardware and so we require
ORIGIN_CPU frontbufer invalidate/flushes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-4-chris@chris-wilson.co.uk
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: vfree() no longer ignores the low bits of the address

Since vfree() now likes to WARN when passed a non-page-aligned pointer,
we need to discard the low bits to comply with it.

Fixes: d31d7cb1460c ("drm/i915: Support for creating write combined type vmaps")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-3-chris@chris-wilson.co.uk