drm/i915: Add ability for tracking buffer objects per client

In order to show per client memory usage lets add some infrastructure
which enables tracking buffer objects owned by clients.

We add a per client list protected by a new per client lock and to support
delayed destruction (post client exit) we make tracked objects hold
references to the owning client.

Also, object memory region teardown is moved to the existing RCU free
callback to allow safe dereference from the fdinfo RCU read section.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107101806.608990-1-tvrtko.ursulin@linux.intel.com

drm/i915: Invalidate the TLBs on each GT

With multi-GT devices, the object may have been bound on each GT.
Invalidate the TLBs across all GT before releasing the pages
back to the system.

Signed-off-by: Chris Wilson <chris.p.wilson@linux.intel.com>
Cc: Fei Yang <fei.yang@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230801141955.383305-4-andi.shyti@linux.intel.com

drm/i915: Add macros to get i915 device from i915_gem_object

We want to stop touching directly i915_gem_object struct members in
intel_frontbuffer code. As a part of this we add helper macro to get i915
device from i915_gem_object.

v2: operate on and return pointer in defined macros

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727064142.751976-2-jouni.hogander@intel.com

drm/i915: use pat_index instead of cache_level

Currently the KMD is using enum i915_cache_level to set caching policy for
buffer objects. This is flaky because the PAT index which really controls
the caching behavior in PTE has far more levels than what's defined in the
enum. In addition, the PAT index is platform dependent, having to translate
between i915_cache_level and PAT index is not reliable, and makes the code
more complicated.

From UMD's perspective there is also a necessity to set caching policy for
performance fine tuning. It's much easier for the UMD to directly use PAT
index because the behavior of each PAT index is clearly defined in Bspec.
Having the abstracted i915_cache_level sitting in between would only cause
more ambiguity. PAT is expected to work much like MOCS already works today,
and by design userspace is expected to select the index that exactly
matches the desired behavior described in the hardware specification.

For these reasons this patch replaces i915_cache_level with PAT index. Also
note, the cache_level is not completely removed yet, because the KMD still
has the need of creating buffer objects with simple cache settings such as
cached, uncached, or writethrough. For kernel objects, cache_level is used
for simplicity and backward compatibility. For Pre-gen12 platforms PAT can
have 1:1 mapping to i915_cache_level, so these two are interchangeable. see
the use of LEGACY_CACHELEVEL.

One consequence of this change is that gen8_pte_encode is no longer working
for gen12 platforms due to the fact that gen12 platforms has different PAT
definitions. In the meantime the mtl_pte_encode introduced specfically for
MTL becomes generic for all gen12 platforms. This patch renames the MTL
PTE encode function into gen12_pte_encode and apply it to all gen12. Even
though this change looks unrelated, but separating them would temporarily
break gen12 PTE encoding, thus squash them in one patch.

Special note: this patch changes the way caching behavior is controlled in
the sense that some objects are left to be managed by userspace. For such
objects we need to be careful not to change the userspace settings.There
are kerneldoc and comments added around obj->cache_coherent, cache_dirty,
and how to bypass the checkings by i915_gem_object_has_cache_level. For
full understanding, these changes need to be looked at together with the
two follow-up patches, one disables the {set|get}_caching ioctl's and the
other adds set_pat extension to the GEM_CREATE uAPI.

Bspec: 63019

Cc: Chris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230509165200.1740-3-fei.yang@intel.com

drm/i915: preparation for using PAT index

This patch is a preparation for replacing enum i915_cache_level with PAT
index. Caching policy for buffer objects is set through the PAT index in
PTE, the old i915_cache_level is not sufficient to represent all caching
modes supported by the hardware.

Preparing the transition by adding some platform dependent data structures
and helper functions to translate the cache_level to pat_index.

cachelevel_to_pat: a platform dependent array mapping cache_level to
pat_index.

max_pat_index: the maximum PAT index recommended in hardware specification
Needed for validating the PAT index passed in from user
space.

i915_gem_get_pat_index: function to convert cache_level to PAT index.

obj_to_i915(obj): macro moved to header file for wider usage.

I915_MAX_CACHE_LEVEL: upper bound of i915_cache_level for the
convenience of coding.

Cc: Chris Wilson <chris.p.wilson@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230509165200.1740-2-fei.yang@intel.com

drm/i915/ttm: Add I915_BO_PREALLOC

Add a mechanism to preserve existing data when creating
a TTM object with the I915_BO_ALLOC_USER flag. This will
be used in the subsequent patch where the I915_BO_ALLOC_USER
flag will be applied to the framebuffer object. For a pre-allocated
framebuffer without the I915_BO_PREALLOC flag.

TTM would clear the content, which is not desirable.
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230404143100.10452-1-nirmoy.das@intel.com

drm/i915/dpt: Treat the DPT BO as a framebuffer

Currently i915_gem_object_is_framebuffer() doesn't treat the
BO containing the framebuffer's DPT as a framebuffer itself.
This means eg. that the shrinker can evict the DPT BO while
leaving the actual FB BO bound, when the DPT is allocated
from regular shmem.

That causes an immediate oops during hibernate as we
try to rewrite the PTEs inside the already evicted
DPT obj.

TODO: presumably this might also be the reason for the
DPT related display faults under heavy memory pressure,
but I'm still not sure how that would happen as the object
should be pinned by intel_dpt_pin() while in active use by
the display engine...

Cc: stable@vger.kernel.org
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Fixes: 0dc987b699ce ("drm/i915/display: Add smem fallback allocation for dpt")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320090522.9909-2-ville.syrjala@linux.intel.com
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>

drm/i915/dpt: Treat the DPT BO as a framebuffer

Currently i915_gem_object_is_framebuffer() doesn't treat the
BO containing the framebuffer's DPT as a framebuffer itself.
This means eg. that the shrinker can evict the DPT BO while
leaving the actual FB BO bound, when the DPT is allocated
from regular shmem.

That causes an immediate oops during hibernate as we
try to rewrite the PTEs inside the already evicted
DPT obj.

TODO: presumably this might also be the reason for the
DPT related display faults under heavy memory pressure,
but I'm still not sure how that would happen as the object
should be pinned by intel_dpt_pin() while in active use by
the display engine...

Cc: stable@vger.kernel.org
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Fixes: 0dc987b699ce ("drm/i915/display: Add smem fallback allocation for dpt")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320090522.9909-2-ville.syrjala@linux.intel.com
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
(cherry picked from commit 779cb5ba64ec7df80675a956c9022929514f517a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915/ttm: consider CCS for backup objects

It seems we can have one or more framebuffers that are still pinned when
suspending lmem, in such a case we end up creating a shmem backup
object, instead of evicting the object directly, but this will skip
copying the CCS aux state, since we don't allocate the extra storage for
the CCS pages as part of the ttm_tt construction. Since we can already
deal with pinned objects just fine, it doesn't seem too nasty to just
extend to support dealing with the CCS aux state, if the object is a
pinned framebuffer. This fixes display corruption (like in gnome-shell)
seen on DG2 when returning from suspend.

Fixes: da0595ae91da ("drm/i915/migrate: Evict and restore the flatccs capable lmem obj")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: <stable@vger.kernel.org> # v5.19+
Tested-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221212171958.82593-2-matthew.auld@intel.com

drm/ttm: merge ttm_bo_api.h and ttm_bo_driver.h v2

Merge and cleanup the two headers into a single description of the
object API. Also move all the documentation to the implementation and
drop unnecessary includes from the header.

No functional change.

v2: minimal checkpatch.pl cleanup

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221125102137.1801-4-christian.koenig@amd.com

drm/i915/ttm: consider CCS for backup objects

It seems we can have one or more framebuffers that are still pinned when
suspending lmem, in such a case we end up creating a shmem backup
object, instead of evicting the object directly, but this will skip
copying the CCS aux state, since we don't allocate the extra storage for
the CCS pages as part of the ttm_tt construction. Since we can already
deal with pinned objects just fine, it doesn't seem too nasty to just
extend to support dealing with the CCS aux state, if the object is a
pinned framebuffer. This fixes display corruption (like in gnome-shell)
seen on DG2 when returning from suspend.

Fixes: da0595ae91da ("drm/i915/migrate: Evict and restore the flatccs capable lmem obj")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: <stable@vger.kernel.org> # v5.19+
Tested-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221212171958.82593-2-matthew.auld@intel.com
(cherry picked from commit 95df9cc24bee8a09d39c62bcef4319b984814e18)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915: allow control over the flags when migrating

In the next patch we want to move the object (if the current resource is
not compatible), to the mappable part of lmem for some display buffers.
Currently that requires being able to unset the I915_BO_ALLOC_GPU_ONLY
hint.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Jianshui Yu <jianshui.yu@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221004131916.233474-3-matthew.auld@intel.com

drm/i915: allow control over the flags when migrating

In the next patch we want to move the object (if the current resource is
not compatible), to the mappable part of lmem for some display buffers.
Currently that requires being able to unset the I915_BO_ALLOC_GPU_ONLY
hint.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Jianshui Yu <jianshui.yu@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221004131916.233474-3-matthew.auld@intel.com
(cherry picked from commit 999f4562077208b683f0519e5f1aa1e5c2fd2191)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915/dgfx: Release mmap on rpm suspend

Release all mmap mapping for all lmem objects which are associated
with userfault such that, while pcie function in D3hot, any access
to memory mappings will raise a userfault.

Runtime resume the dgpu(when gem object lies in lmem).
This will transition the dgpu graphics function to D0
state if it was in D3 in order to access the mmap memory
mappings.

v2:
- Squashes the patches. [Matt Auld]
- Add adequate locking for lmem_userfault_list addition. [Matt Auld]
- Reused obj->userfault_count to avoid double addition. [Matt Auld]
- Added i915_gem_object_lock to check
i915_gem_object_is_lmem. [Matt Auld]

v3:
- Use i915_ttm_cpu_maps_iomem. [Matt Auld]
- Fix 'ret == 0 to ret == VM_FAULT_NOPAGE'. [Matt Auld]
- Reuse obj->userfault_count as a bool 0 or 1. [Matt Auld]
- Delete the mmaped obj from lmem_userfault_list in obj
destruction path. [Matt Auld]
- Get a wakeref for object destruction patch. [Matt Auld]
- Use intel_wakeref_auto to delay runtime PM. [Matt Auld]

v4:
- Avoid using mmo offset to get the vma_node. [Matt Auld]
- Added comment to use the lmem_userfault_lock. [Matt Auld]
- Get lmem_userfault_lock in i915_gem_object_release_mmap_offset.
[Matt Auld]
- Fixed kernel test robot generated warning.

v5:
- Addressed the cosmetics comments. [Andi]
- Changed i915_gem_runtime_pm_object_release_mmap_offset() name to
i915_gem_object_runtime_pm_release_mmap_offset() to be rhythmic.

PCIe Specs 5.3.1.4.1

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6331
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220913152714.16541-3-anshuman.gupta@intel.com

drm/i915/gt: Batch TLB invalidations

Invalidate TLB in batches, in order to reduce performance regressions.

Currently, every caller performs a full barrier around a TLB
invalidation, ignoring all other invalidations that may have already
removed their PTEs from the cache. As this is a synchronous operation
and can be quite slow, we cause multiple threads to contend on the TLB
invalidate mutex blocking userspace.

We only need to invalidate the TLB once after replacing our PTE to
ensure that there is no possible continued access to the physical
address before releasing our pages. By tracking a seqno for each full
TLB invalidate we can quickly determine if one has been performed since
rewriting the PTE, and only if necessary trigger one for ourselves.

That helps to reduce the performance regression introduced by TLB
invalidate logic.

[mchehab: rebased to not require moving the code to a separate file]

Cc: stable@vger.kernel.org
Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Cc: Fei Yang <fei.yang@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4e97ef5deb6739cadaaf40aa45620547e9c4ec06.1658924372.git.mchehab@kernel.org

drm/i915/gt: Batch TLB invalidations

Invalidate TLB in batches, in order to reduce performance regressions.

Currently, every caller performs a full barrier around a TLB
invalidation, ignoring all other invalidations that may have already
removed their PTEs from the cache. As this is a synchronous operation
and can be quite slow, we cause multiple threads to contend on the TLB
invalidate mutex blocking userspace.

We only need to invalidate the TLB once after replacing our PTE to
ensure that there is no possible continued access to the physical
address before releasing our pages. By tracking a seqno for each full
TLB invalidate we can quickly determine if one has been performed since
rewriting the PTE, and only if necessary trigger one for ourselves.

That helps to reduce the performance regression introduced by TLB
invalidate logic.

[mchehab: rebased to not require moving the code to a separate file]

Cc: stable@vger.kernel.org
Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Cc: Fei Yang <fei.yang@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4e97ef5deb6739cadaaf40aa45620547e9c4ec06.1658924372.git.mchehab@kernel.org
(cherry picked from commit 5d36acb7198b0e5eb88e6b701f9ad7b9448f8df9)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915/ttm: handle blitter failure on DG2

If the move or clear operation somehow fails, and the memory underneath
is not cleared, like when moving to lmem, then we currently fallback to
memcpy or memset. However with small-BAR systems this fallback might no
longer be possible. For now we use the set_wedged sledgehammer if we
ever encounter such a scenario, and mark the object as borked to plug
any holes where access to the memory underneath can happen. Add some
basic selftests to exercise this.

v2:
- In the selftests make sure we grab the runtime pm around the reset.
Also make sure we grab the reset lock before checking if the device
is wedged, since the wedge might still be in-progress and hence the
bit might not be set yet.
- Don't wedge or put the object into an unknown state, if the request
construction fails (or similar). Just returning an error and
skipping the fallback should be safe here.
- Make sure we wedge each gt. (Thomas)
- Peek at the unknown_state in io_reserve, that way we don't have to
export or hand roll the fault_wait_for_idle. (Thomas)
- Add the missing read-side barriers for the unknown_state. (Thomas)
- Some kernel-doc fixes. (Thomas)
v3:
- Tweak the ordering of the set_wedged, also add FIXME.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220629174350.384910-11-matthew.auld@intel.com

drm/i915/ttm: wire up the object offset

For the ttm backend we can use existing placements fpfn and lpfn to
force the allocator to place the object at the requested offset,
potentially evicting stuff if the spot is currently occupied.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220315181425.576828-5-matthew.auld@intel.com

drm/i915: add I915_BO_ALLOC_GPU_ONLY

If the user doesn't require CPU access for the buffer, then
ALLOC_GPU_ONLY should be used, in order to prioritise allocating in the
non-mappable portion of LMEM, on devices with small BAR.

v2(Thomas):
- The BO_ALLOC_TOPDOWN naming here is poor, since this is pure lies on
systems that don't even have small BAR. A better name is GPU_ONLY,
which is accurate regardless of the configuration.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220225145502.331818-3-matthew.auld@intel.com

drm/i915: Use the vma resource as argument for gtt binding / unbinding

When introducing asynchronous unbinding, the vma itself may no longer
be alive when the actual binding or unbinding takes place.

Update the gtt i915_vma_ops accordingly to take a struct i915_vma_resource
instead of a struct i915_vma for the bind_vma() and unbind_vma() ops.
Similarly change the insert_entries() op for struct i915_address_space.

Replace a couple of i915_vma_snapshot members with their newly introduced
i915_vma_resource counterparts, since they have the same lifetime.

Also make sure to avoid changing the struct i915_vma_flags (in particular
the bind flags) async. That should now only be done sync under the
vm mutex.

v2:
- Update the vma_res::bound_flags when binding to the aliased ggtt
v6:
- Remove I915_VMA_ALLOC_BIT (Matthew Auld)
- Change some members of struct i915_vma_resource from unsigned long to u64
(Matthew Auld)
v7:
- Fix vma resource size parameters to be u64 rather than unsigned long
(Matthew Auld)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220110172219.107131-3-thomas.hellstrom@linux.intel.com

drm/i915/ttm: add unmap_virtual callback

Ensure we call ttm_bo_unmap_virtual when releasing the pages.
Importantly this should now handle the ttm swapping case, and all other
places that already call into i915_ttm_move_notify().

v2: fix up the selftest

Fixes: cf3e3e86d779 ("drm/i915: Use ttm mmap handling for ttm bo's.")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220106174910.280616-3-matthew.auld@intel.com

drm/i915: clean up shrinker_release_pages

Add some proper flags for the different modes, and shorten the name to
something more snappy.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215110746.865-2-matthew.auld@intel.com

drm/i915: remove writeback hook

Ditch the writeback hook and drop i915_gem_object_writeback(). We
already support the shrinker_release_pages hook which can just call
shmem_writeback directly.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215110746.865-1-matthew.auld@intel.com

drm/i915: Flush TLBs before releasing backing store

We need to flush TLBs before releasing backing store otherwise userspace
is able to encounter stale entries if a) it is not declaring access to
certain buffers and b) it races with the backing store release from a
such undeclared execution already executing on the GPU in parallel.

The approach taken is to mark any buffer objects which were ever bound
to the GPU and to trigger a serialized TLB flush when their backing
store is released.

Alternatively the flushing could be done on VMA unbind, at which point
we would be able to ascertain whether there is potential a parallel GPU
execution (which could race), but essentially it boils down to paying
the cost of TLB flushes potentially needlessly at VMA unbind time (when
the backing store is not known to be going away so not needed for
safety), versus potentially needlessly at backing store relase time
(since we at that point cannot tell whether there is anything executing
on the GPU which uses that object).

Thereforce simplicity of implementation has been chosen for now with
scope to benchmark and refine later as required.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reported-by: Sushma Venkatesh Reddy <sushma.venkatesh.reddy@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/i915/ttm: add unmap_virtual callback

Ensure we call ttm_bo_unmap_virtual when releasing the pages.
Importantly this should now handle the ttm swapping case, and all other
places that already call into i915_ttm_move_notify().

v2: fix up the selftest

Fixes: cf3e3e86d779 ("drm/i915: Use ttm mmap handling for ttm bo's.")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220106174910.280616-3-matthew.auld@intel.com
(cherry picked from commit 903e0387270eef14a711c0feb23b7bf62d2480df)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915/ttm: Correctly handle waiting for gpu when shrinking

With async migration, the shrinker may end up wanting to release the
pages of an object while the migration blit is still running, since
the GT migration code doesn't set up VMAs and the shrinker is thus
oblivious to the fact that the GPU is still using the pages.

Add waiting for gpu in the shrinker_release_pages() op and an
argument to that function indicating whether the shrinker expects it
to not wait for gpu. In the latter case the shrinker_release_pages()
op will return -EBUSY if the object is not idle.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211122214554.371864-5-thomas.hellstrom@linux.intel.com

drm/i915: Introduce refcounted sg-tables

As we start to introduce asynchronous failsafe object migration,
where we update the object state and then submit asynchronous
commands we need to record what memory resources are actually used
by various part of the command stream. Initially for three purposes:

1) Error capture.
2) Asynchronous migration error recovery.
3) Asynchronous vma bind.

At the time where these happens, the object state may have been updated
to be several migrations ahead and object sg-tables discarded.

In order to make it possible to keep sg-tables with memory resource
information for these operations, introduce refcounted sg-tables that
aren't freed until the last user is done with them.

The alternative would be to reference information sitting on the
corresponding ttm_resources which typically have the same lifetime as
these refcountes sg_tables, but that leads to other awkward constructs:
Due to the design direction chosen for ttm resource managers that would
lead to diamond-style inheritance, the LMEM resources may sometimes be
prematurely freed, and finally the subclassed struct ttm_resource would
have to bleed into the asynchronous vma bind code.

v3:
- Address a number of style issues (Matthew Auld)
v4:
- Dont check for st->sgl being NULL in i915_ttm_tt__shmem_unpopulate(),
that should never happen. (Matthew Auld)
v5:
- Fix a Potential double-free (Matthew Auld)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211101122444.114607-1-thomas.hellstrom@linux.intel.com

drm/i915/ttm: move shrinker management into adjust_lru

We currently just evict lmem objects to system memory when under memory
pressure. For this case we might lack the usual object mm.pages, which
effectively hides the pages from the i915-gem shrinker, until we
actually "attach" the TT to the object, or in the case of lmem-only
objects it just gets migrated back to lmem when touched again.

For all cases we can just adjust the i915 shrinker LRU each time we also
adjust the TTM LRU. The two cases we care about are:

1) When something is moved by TTM, including when initially populating
an object. Importantly this covers the case where TTM moves something from
lmem <-> smem, outside of the normal get_pages() interface, which
should still ensure the shmem pages underneath are reclaimable.

2) When calling into i915_gem_object_unlock(). The unlock should
ensure the object is removed from the shinker LRU, if it was indeed
swapped out, or just purged, when the shrinker drops the object lock.

v2(Thomas):
- Handle managing the shrinker LRU in adjust_lru, where it is always
safe to touch the object.
v3(Thomas):
- Pretty much a re-write. This time piggy back off the shrink_pin
stuff, which actually seems to fit quite well for what we want here.
v4(Thomas):
- Just use a simple boolean for tracking ttm_shrinkable.
v5:
- Ensure we call adjust_lru when faulting the object, to ensure the
pages are visible to the shrinker, if needed.
- Add back the adjust_lru when in i915_ttm_move (Thomas)
v6(Reported-by: kernel test robot <lkp@intel.com>):
- Remove unused i915_tt

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #v4
Link: https://patchwork.freedesktop.org/patch/msgid/20211018091055.1998191-6-matthew.auld@intel.com

drm/i915: add some kernel-doc for shrink_pin and friends

Attempt to document shrink_pin and the other relevant interfaces that
interact with it, before we start messing with it.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211018091055.1998191-5-matthew.auld@intel.com

drm/i915/ttm: add tt shmem backend

For cached objects we can allocate our pages directly in shmem. This
should make it possible(in a later patch) to utilise the existing
i915-gem shrinker code for such objects. For now this is still disabled.

v2(Thomas):
- Add optional try_to_writeback hook for objects. Importantly we need
to check if the object is even still shrinkable; in between us
dropping the shrinker LRU lock and acquiring the object lock it could for
example have been moved. Also we need to differentiate between
"lazy" shrinking and the immediate writeback mode. Also later we need to
handle objects which don't even have mm.pages, so bundling this into
put_pages() would require somehow handling that edge case, hence
just letting the ttm backend handle everything in try_to_writeback
doesn't seem too bad.
v3(Thomas):
- Likely a bad idea to touch the object from the unpopulate hook,
since it's not possible to hold a reference, without also creating
circular dependency, so likely this is too fragile. For now just
ensure we at least mark the pages as dirty/accessed when called from the
shrinker on WILLNEED objects.
- s/try_to_writeback/shrinker_release_pages, since this can do more
than just writeback.
- Get rid of do_backup boolean and just set the SWAPPED flag prior to
calling unpopulate.
- Keep shmem_tt as lowest priority for the TTM LRU bo_swapout walk, since
these just get skipped anyway. We can try to come up with something
better later.
v4(Thomas):
- s/PCI_DMA/DMA/. Also drop NO_KERNEL_MAPPING and NO_WARN, which
apparently doesn't do anything with streaming mappings.
- Just pass along the error for ->truncate, and assume nothing.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Oak Zeng <oak.zeng@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Oak Zeng <oak.zeng@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211018091055.1998191-2-matthew.auld@intel.com

drm/i915: expand on the kernel-doc for cache_dirty

Add some details around non-LLC platforms and cflushing, when dealing
with the flush-on-acquire, which is potentially security sensitive.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211018174508.2137279-7-matthew.auld@intel.com

drm/i915/pxp: interfaces for using protected objects

This api allow user mode to create protected buffers and to mark
contexts as making use of such objects. Only when using contexts
marked in such a way is the execution guaranteed to work as expected.

Contexts can only be marked as using protected content at creation time
(i.e. the parameter is immutable) and they must be both bannable and not
recoverable. Given that the protected session gets invalidated on
suspend, contexts created this way hold a runtime pm wakeref until
they're either destroyed or invalidated.

All protected objects and contexts will be considered invalid when the
PXP session is destroyed and all new submissions using them will be
rejected. All intel contexts within the invalidated gem contexts will be
marked banned. Userspace can detect that an invalidation has occurred via
the RESET_STATS ioctl, where we report it the same way as a ban due to a
hang.

v5: squash patches, rebase on proto_ctx, update kerneldoc

v6: rebase on obj create_ext changes

v7: Use session counter to check if an object it valid, hold wakeref in
context, don't add a new flag to RESET_STATS (Daniel)

v8: don't increase guilty count for contexts banned during pxp
invalidation (Rodrigo)

v9: better comments, avoid wakeref put race between pxp_inval and
context_close, add usage examples (Rodrigo)

v10: modify internal set/get-protected-context functions to not
return -ENODEV when setting PXP param to false or getting param
when running on pxp-unsupported hw or getting param when i915
was built with CONFIG_PXP off

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-11-alan.previn.teres.alexis@intel.com

drm/i915: Reduce the number of objects subject to memcpy recover

We really only need memcpy restore for objects that affect the
operability of the migrate context. That is, primarily the page-table
objects of the migrate VM.

Add an object flag, I915_BO_ALLOC_PM_EARLY for objects that need early
restores using memcpy and a way to assign LMEM page-table object flags
to be used by the vms.

Restore objects without this flag with the gpu blitter and only objects
carrying the flag using TTM memcpy.

Initially mark the migrate, gt, gtt and vgpu vms to use this flag, and
defer for a later audit which vms actually need it. Most importantly, user-
allocated vms with pinned page-table objects can be restored using the
blitter.

Performance-wise memcpy restore is probably as fast as gpu restore if not
faster, but using gpu restore will help tackling future restrictions in
mappable LMEM size.

v4:
- Don't mark the aliasing ppgtt page table flags for early resume, but
rather the ggtt page table flags as intended. (Matthew Auld)
- The check for user buffer objects during early resume is pointless, since
they are never marked I915_BO_ALLOC_PM_EARLY. (Matthew Auld)
v5:
- Mark GuC LMEM objects with I915_BO_ALLOC_PM_EARLY to have them restored
before we fire up the migrate context.

Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210922062527.865433-8-thomas.hellstrom@linux.intel.com

drm/i915: Don't back up pinned LMEM context images and rings during suspend

Pinned context images are now reset during resume. Don't back them up,
and assuming that rings can be assumed empty at suspend, don't back them
up either.

Introduce a new object flag, I915_BO_ALLOC_PM_VOLATILE meaning that an
object is allowed to lose its content on suspend.

v3:
- Slight documentation clarification (Matthew Auld)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210922062527.865433-7-thomas.hellstrom@linux.intel.com

drm/i915 Implement LMEM backup and restore for suspend / resume

Just evict unpinned objects to system. For pinned LMEM objects,
make a backup system object and blit the contents to that.

Backup is performed in three steps,
1: Opportunistically evict evictable objects using the gpu blitter.
2: After gt idle, evict evictable objects using the gpu blitter. This will
be modified in an upcoming patch to backup pinned objects that are not used
by the blitter itself.
3: Backup remaining pinned objects using memcpy.

Also move uC suspend to after 2) to make sure we have a functional GuC
during 2) if using GuC submission.

v2:
- Major refactor to make sure gem_exec_suspend@hang-SX subtests work, and
suspend / resume works with a slightly modified GuC submission enabling
patch series.

v3:
- Fix a potential use-after-free (Matthew Auld)
- Use i915_gem_object_create_shmem() instead of
i915_gem_object_create_region (Matthew Auld)
- Minor simplifications (Matthew Auld)
- Fix up kerneldoc for i195_ttm_restore_region().
- Final lmem_suspend() call moved to i915_gem_backup_suspend from
i915_gem_suspend_late, since the latter gets called at driver unload
and we don't unnecessarily want to run it at that time.

v4:
- Interface change of ttm- & lmem suspend / resume functions to use
flags rather than bools. (Matthew Auld)
- Completely drop the i915_gem_backup_suspend change (Matthew Auld)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210922062527.865433-5-thomas.hellstrom@linux.intel.com

drm/i915/ehl: unconditionally flush the pages on acquire

EHL and JSL add the 'Bypass LLC' MOCS entry, which should make it
possible for userspace to bypass the GTT caching bits set by the kernel,
as per the given object cache_level. This is troublesome since the heavy
flush we apply when first acquiring the pages is skipped if the kernel
thinks the object is coherent with the GPU. As a result it might be
possible to bypass the cache and read the contents of the page directly,
which could be stale data. If it's just a case of userspace shooting
themselves in the foot then so be it, but since i915 takes the stance of
always zeroing memory before handing it to userspace, we need to prevent
this.

v2: this time actually set cache_dirty in put_pages()
v3: move to get_pages() which looks simpler

BSpec: 34007
References: 046091758b50 ("Revert "drm/i915/ehl: Update MOCS table for EHL"")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Cc: Francisco Jerez <francisco.jerez.plata@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris.p.wilson@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723105045.400841-2-matthew.auld@intel.com

drm/i915: document caching related bits

Try to document the object caching related bits, like cache_coherent and
cache_dirty.

v2(Ville):
- As pointed out by Ville, fix the completely incorrect assumptions
about the "partial" coherency on shared LLC platforms.
v3(Daniel):
- Fix nonsense about "dirtying" the cache with reads.
v4(Daniel):
- Various improvements, including adding some more details for WT.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723105045.400841-1-matthew.auld@intel.com

drm/i915: Add TTM offset argument to mmap.

The FIXED mapping is only used for ttm, and tells userspace that the
mapping type is pre-defined. This disables the other type of mmap
offsets when discrete memory is used, so fix the selftests as well.

Document the struct as well, so it shows up in docbook.

Cc: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[mauld: Included minor fixes from the review comments]
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714122833.766586-1-maarten.lankhorst@linux.intel.com

drm/i915/gem: Implement object migration

Introduce an interface to migrate objects between regions.
This is primarily intended to migrate objects to LMEM for display and
to SYSTEM for dma-buf, but might be reused in one form or another for
performance-based migration.

v2:
- Verify that the memory region given as an id really exists.
(Reported by Matthew Auld)
- Call i915_gem_object_{init,release}_memory_region() when switching region
to handle also switching region lists. (Reported by Matthew Auld)
v3:
- Fix i915_gem_object_can_migrate() to return true if object is already in
the correct region, even if the object ops doesn't have a migrate()
callback.
- Update typo in commit message.
- Fix kerneldoc of i915_gem_object_wait_migration().
v4:
- Improve documentation (Suggested by Mattew Auld and Michael Ruhl)
- Always assume TTM migration hits a TTM move and unsets the pages through
move_notify. (Reported by Matthew Auld)
- Add a dma_fence_might_wait() annotation to
i915_gem_object_wait_migration() (Suggested by Daniel Vetter)
v5:
- Re-add might_sleep() instead of __dma_fence_might_wait(), Sent
v4 with the wrong version, didn't compile and __dma_fence_might_wait()
is not exported.
- Added an R-B.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210629151203.209465-2-thomas.hellstrom@linux.intel.com

drm/i915: Update object placement flags to be mutable

The object ops i915_GEM_OBJECT_HAS_IOMEM and the object
I915_BO_ALLOC_STRUCT_PAGE flags are considered immutable by
much of our code. Introduce a new mem_flags member to hold these
and make sure checks for these flags being set are either done
under the object lock or with pages properly pinned. The flags
will change during migration under the object lock.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210624084240.270219-2-thomas.hellstrom@linux.intel.com

drm/i915/ttm: remove node usage in our naming

Now that ttm_resource_manager just returns a generic ttm_resource we
don't need to reference the mm_node stuff anymore which mostly only
makes sense for drm_mm_node. In the next few patches we want switch over
to the ttm_buddy_man which is just another type of ttm_resource so
reflect that in the naming.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210616152501.394518-5-matthew.auld@intel.com

drm/i915: Use ttm mmap handling for ttm bo's.

Use the ttm handlers for servicing page faults, and vm_access.

We do our own validation of read-only access, otherwise use the
ttm handlers as much as possible.

Because the ttm handlers expect the vma_node at vma->base, we slightly
need to massage the mmap handlers to look at vma_node->driver_private
to fetch the bo, if it's NULL, we assume i915's normal mmap_offset uapi
is used.

This is the easiest way to achieve compatibility without changing ttm's
semantics.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210610070152.572423-5-thomas.hellstrom@linux.intel.com

drm/i915/ttm: Introduce a TTM i915 gem object backend

Most logical place to introduce TTM buffer objects is as an i915
gem object backend. We need to add some ops to account for added
functionality like delayed delete and LRU list manipulation.

Initially we support only LMEM and SYSTEM memory, but SYSTEM
(which in this case means evicted LMEM objects) is not
visible to i915 GEM yet. The plan is to move the i915 gem system region
over to the TTM system memory type in upcoming patches.

We set up GPU bindings directly both from LMEM and from the system region,
as there is no need to use the legacy TTM_TT memory type. We reserve
that for future porting of GGTT bindings to TTM.

Remove the old lmem backend.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210610070152.572423-2-thomas.hellstrom@linux.intel.com

drm/i915/ttm: Embed a ttm buffer object in the i915 gem object

Embed a struct ttm_buffer_object into the i915 gem object, making sure
we alias the gem object part. It's a bit unfortunate that the
struct ttm_buffer_ojbect embeds a gem object since we otherwise could
make the TTM part private to the TTM backend, and use the usual
i915 gem object for the other backends.
To make this a bit more storage efficient for the other backends,
we'd have to use a pointer for the gem object which would require
a lot of changes in the driver. We postpone that for later.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-3-thomas.hellstrom@linux.intel.com

drm/i915/ttm Initialize the ttm device and memory managers

Temporarily remove the buddy allocator and related selftests
and hook up the TTM range manager for i915 regions.

Also modify the mock region selftests somewhat to account for a
fragmenting manager.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-2-thomas.hellstrom@linux.intel.com

drm/i915: Don't free shared locks while shared

We are currently sharing the VM reservation locks across a number of
gem objects with page-table memory. Since TTM will individiualize the
reservation locks when freeing objects, including accessing the shared
locks, make sure that the shared locks are not freed until that is done.
For PPGTT we add an additional refcount, for GGTT we take additional
measures to make sure objects sharing the GGTT reservation lock are
freed at GGTT takedown

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210601074654.3103-3-thomas.hellstrom@linux.intel.com

drm/i915/lmem: support optional CPU clearing for special internal use

For some internal device local-memory objects it would be useful to have
an option to CPU clear the pages upon gathering the backing store. Note
that this might be before the blitter is useable, which is the case for
some internal GuC objects.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@linux.intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Dave Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: mesa-dev@lists.freedesktop.org
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429103056.407067-7-matthew.auld@intel.com

drm/i915/uapi: implement object placement extension

Add new extension to support setting an immutable-priority-list of
potential placements, at creation time.

If we use the normal gem_create or gem_create_ext without the
extensions/placements then we still get the old behaviour with only
placing the object in system memory.

v2(Daniel & Jason):
- Add a bunch of kernel-doc
- Simplify design for placements extension

Testcase: igt/gem_create/create-ext-placement-sanity-check
Testcase: igt/gem_create/create-ext-placement-each
Testcase: igt/gem_create/create-ext-placement-all
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@linux.intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Dave Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: mesa-dev@lists.freedesktop.org
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429103056.407067-6-matthew.auld@intel.com

drm/i915: Finally remove obj->mm.lock.

With all callers and selftests fixed to use ww locking, we can now
finally remove this lock.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-62-maarten.lankhorst@linux.intel.com

drm/i915: Fix userptr so we do not have to worry about obj->mm.lock, v7.

Instead of doing what we do currently, which will never work with
PROVE_LOCKING, do the same as AMD does, and something similar to
relocation slowpath. When all locks are dropped, we acquire the
pages for pinning. When the locks are taken, we transfer those
pages in .get_pages() to the bo. As a final check before installing
the fences, we ensure that the mmu notifier was not called; if it is,
we return -EAGAIN to userspace to signal it has to start over.

Changes since v1:
- Unbinding is done in submit_init only. submit_begin() removed.
- MMU_NOTFIER -> MMU_NOTIFIER
Changes since v2:
- Make i915->mm.notifier a spinlock.
Changes since v3:
- Add WARN_ON if there are any page references left, should have been 0.
- Return 0 on success in submit_init(), bug from spinlock conversion.
- Release pvec outside of notifier_lock (Thomas).
Changes since v4:
- Mention why we're clearing eb->[i + 1].vma in the code. (Thomas)
- Actually check all invalidations in eb_move_to_gpu. (Thomas)
- Do not wait when process is exiting to fix gem_ctx_persistence.userptr.
Changes since v5:
- Clarify why check on PF_EXITING is (temporarily) required.
Changes since v6:
- Ensure userptr validity is checked in set_domain through a special path.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
[danvet: s/kfree/kvfree/ in i915_gem_object_userptr_drop_ref in the
previous review round, but which got lost. The other open questions
around page refcount are imo better discussed in a separate series,
with amdgpu folks involved].
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-17-maarten.lankhorst@linux.intel.com

drm/i915: Make compilation of userptr code depend on MMU_NOTIFIER.

Now that unsynchronized mappings are removed, the only time userptr
works is when the MMU notifier is enabled. Put all of the userptr
code behind a mmu notifier ifdef.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-16-maarten.lankhorst@linux.intel.com

drm/i915: Move HAS_STRUCT_PAGE to obj->flags

We want to remove the changing of ops structure for attaching
phys pages, so we need to kill off HAS_STRUCT_PAGE from ops->flags,
and put it in the bo.

This will remove a potential race of dereferencing the wrong obj->ops
without ww mutex held.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
[danvet: apply with wiggle]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-8-maarten.lankhorst@linux.intel.com

drm/i915/gem: Use shrinkable status for unknown swizzle quirks

Give obj->mm.quirked a name much more reflective of its purpose
(i915_gem_object_has_tiling_quirk) and move it from the obj->mm field as
it doesn't denote a quirk of the backing store, but a quirk in the
object in its treatment of the backing pages, similar to tiling modes.

Then instead of abusing the pinned status of the buffer to protect it
from the shrinker, we can instead hide the buffer from the shrinker so
it is never considered for being swapped.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210119214336.1463-4-chris@chris-wilson.co.uk

drm/i915/gem: Move stolen node into GEM object union

The obj->stolen is currently used to identify an object allocated from
stolen memory. This dates back to when there were just 1.5 types of
objects, an object backed by shmemfs and an object backed by shmemfs
with a contiguous physical address. Now that we have several different
types of objects, we no longer want to treat stolen objects as a special
case.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210119214336.1463-3-chris@chris-wilson.co.uk

drm/i915: move i915_map_type into i915_gem_object_types.h

Looks like it belongs there anyway, otherwise we have to include the
entirety of i915_gem_object.h just to get at the enum.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210119133106.66294-3-matthew.auld@intel.com

drm/i915/gem: Allow backends to override pread implementation

As there are more and more complicated interactions between the different
backing stores and userspace, push the control into the backends rather
than accumulate them all inside the ioctl handlers.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105154934.16022-1-chris@chris-wilson.co.uk
(cherry picked from commit 0049b688459b846f819b6e51c24cd0781fcfde41)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915/gem: Allow backends to override pread implementation

As there are more and more complicated interactions between the different
backing stores and userspace, push the control into the backends rather
than accumulate them all inside the ioctl handlers.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105154934.16022-1-chris@chris-wilson.co.uk

drm/i915: Fix DMA mapped scatterlist lookup

As the previous patch fixed the places where we walk the whole scatterlist
for DMA addresses, this patch fixes the random lookup functionality.

To achieve this we have to add a second lookup iterator and add a
i915_gem_object_get_sg_dma helper, to be used analoguous to existing
i915_gem_object_get_sg_dma. Therefore two lookup caches are maintained per
object and they are flushed at the same point for simplicity. (Strictly
speaking the DMA cache should be flushed from i915_gem_gtt_finish_pages,
but today this conincides with unsetting of the pages in general.)

Partial VMA view is then fixed to use the new DMA lookup and properly
query sg length.

v2:
* Checkpatch.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Tom Murphy <murphyt7@tcd.ie>
Cc: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201006092508.1064287-2-tvrtko.ursulin@linux.intel.com

drm/i915: Add an implementation for i915_gem_ww_ctx locking, v2.

i915_gem_ww_ctx is used to lock all gem bo's for pinning and memory
eviction. We don't use it yet, but lets start adding the definition
first.

To use it, we have to pass a non-NULL ww to gem_object_lock, and don't
unlock directly. It is done in i915_gem_ww_ctx_fini.

Changes since v1:
- Change ww_ctx and obj order in locking functions (Jonas Lahtinen)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-6-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/gt: Switch to object allocations for page directories

The GEM object is grossly overweight for the practicality of tracking
large numbers of individual pages, yet it is currently our only
abstraction for tracking DMA allocations. Since those allocations need
to be reserved upfront before an operation, and that we need to break
away from simple system memory, we need to ditch using plain struct page
wrappers.

In the process, we drop the WC mapping as we ended up clflushing
everything anyway due to various issues across a wider range of
platforms. Though in a future step, we need to drop the kmap_atomic
approach which suggests we need to pre-map all the pages and keep them
mapped.

v2: Verify our large scratch page is suitably DMA aligned; and manually
clear the scratch since we are allocating plain struct pages full of
prior content.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200729164219.5737-2-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/gem: Move obj->lut_list under its own lock

The obj->lut_list is traversed when the object is closed as the file
table is destroyed during process termination. As this occurs before we
kill any outstanding context if, due to some bug or another, the closure
is blocked, then we fail to shootdown any inflight operations
potentially leaving the GPU spinning forever. As we only need to guard
the list against concurrent closures and insertions, the hold is short
and merits being treated as a simple spinlock.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701084439.17025-1-chris@chris-wilson.co.uk

drm/i915/gem: Give each object class a friendly name

Name the object classes and their offspring for easier lockdep
debugging.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200529183204.16850-2-chris@chris-wilson.co.uk

drm/i915/gem: Drop cached obj->bind_count

We cached the number of vma bound to the object in order to speed up
shrinker decisions. This has been superseded by being more proactive in
removing objects we cannot shrink from the shrinker lists, and so we can
drop the clumsy attempt at atomically counting the bind count and
comparing it to the number of pinned mappings of the object. This will
only get more clumsier with asynchronous binding and unbinding.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401223924.16667-1-chris@chris-wilson.co.uk

drm/i915: Wean off drm_pci_alloc/drm_pci_free

drm_pci_alloc and drm_pci_free are just very thin wrappers around
dma_alloc_coherent, with a note that we should be removing them.
Furthermore since

commit de09d31dd38a50fdce106c15abd68432eebbd014
Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Date: Fri Jan 15 16:51:42 2016 -0800

page-flags: define PG_reserved behavior on compound pages

As far as I can see there's no users of PG_reserved on compound pages.
Let's use PF_NO_COMPOUND here.

drm_pci_alloc has been declared broken since it mixes GFP_COMP and
SetPageReserved. Avoid this conflict by weaning ourselves off using the
abstraction and using the dma functions directly.

Reported-by: Taketo Kabe
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1027
Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.5+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200202153934.3899472-1-chris@chris-wilson.co.uk
(cherry picked from commit c6790dc22312f592c1434577258b31c48c72d52a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915/gem: Store mmap_offsets in an rbtree rather than a plain list

Currently we create a new mmap_offset for every call to
mmap_offset_ioctl. This exposes ourselves to an abusive client that may
simply create new mmap_offsets ad infinitum, which will exhaust physical
memory and the virtual address space. In addition to the exhaustion, a
very long linear list of mmap_offsets causes other clients using the
object to incur long list walks -- these long lists can also be
generated by simply having many clients generate their own mmap_offset.

However, we can simply use the drm_vma_node itself to manage the file
association (allow/revoke) dropping our need to keep an mmo per-file.
Then if we keep a small rbtree of per-type mmap_offsets, we can lookup
duplicate requests quickly.

Fixes: cc662126b413 ("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200120104924.4000706-3-chris@chris-wilson.co.uk
(cherry picked from commit 7865559872074a9ab169c87915504661d630addf)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915: Never allow userptr into the new mapping types

Commit 4f2a572eda67 ("drm/i915/userptr: Never allow userptr into the
mappable GGTT") made I915_GEM_MMAP_GTT IOCTLs to fail when attempted
on a userptr object in order to protect from a lockdep splat. Later
on, new mapping types were introduced by commit cc662126b413
("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET"). Those new mapping
types suffer from the same lockdep splat issue but they now succeed
when tried on top of a userptr object. Fix it.

v2: Don't play with the -ENODEV driver response (Chris)

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200204162302.1299516-1-chris@chris-wilson.co.uk

drm/i915: Wean off drm_pci_alloc/drm_pci_free

drm_pci_alloc and drm_pci_free are just very thin wrappers around
dma_alloc_coherent, with a note that we should be removing them.
Furthermore since

commit de09d31dd38a50fdce106c15abd68432eebbd014
Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Date: Fri Jan 15 16:51:42 2016 -0800

page-flags: define PG_reserved behavior on compound pages

As far as I can see there's no users of PG_reserved on compound pages.
Let's use PF_NO_COMPOUND here.

drm_pci_alloc has been declared broken since it mixes GFP_COMP and
SetPageReserved. Avoid this conflict by weaning ourselves off using the
abstraction and using the dma functions directly.

Reported-by: Taketo Kabe
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1027
Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.5+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200202153934.3899472-1-chris@chris-wilson.co.uk

drm/i915/gem: Store mmap_offsets in an rbtree rather than a plain list

Currently we create a new mmap_offset for every call to
mmap_offset_ioctl. This exposes ourselves to an abusive client that may
simply create new mmap_offsets ad infinitum, which will exhaust physical
memory and the virtual address space. In addition to the exhaustion, a
very long linear list of mmap_offsets causes other clients using the
object to incur long list walks -- these long lists can also be
generated by simply having many clients generate their own mmap_offset.

However, we can simply use the drm_vma_node itself to manage the file
association (allow/revoke) dropping our need to keep an mmo per-file.
Then if we keep a small rbtree of per-type mmap_offsets, we can lookup
duplicate requests quickly.

Fixes: cc662126b413 ("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200120104924.4000706-3-chris@chris-wilson.co.uk

drm/i915: Hold reference to intel_frontbuffer as we track activity

Since obj->frontbuffer is no longer protected by the struct_mutex, as we
are processing the execbuf, it may be removed. Mark the
intel_frontbuffer as rcu protected, and so acquire a reference to
the struct as we track activity upon it.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/827
Fixes: 8e7cb1799b4f ("drm/i915: Extract intel_frontbuffer active tracking")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v5.4+
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218104043.3539458-1-chris@chris-wilson.co.uk
(cherry picked from commit da42104f589d979bbe402703fd836cec60befae1)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915: Hold reference to intel_frontbuffer as we track activity

Since obj->frontbuffer is no longer protected by the struct_mutex, as we
are processing the execbuf, it may be removed. Mark the
intel_frontbuffer as rcu protected, and so acquire a reference to
the struct as we track activity upon it.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/827
Fixes: 8e7cb1799b4f ("drm/i915: Extract intel_frontbuffer active tracking")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v5.4+
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218104043.3539458-1-chris@chris-wilson.co.uk

drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET

This is really just an alias of mmap_gtt. The 'mmap offset' nomenclature
comes from the value returned by this ioctl which is the offset into the
device fd which userpace uses with mmap(2).

mmap_gtt was our initial mmap_offset implementation, this extends
our CPU mmap support to allow additional fault handlers that depends on
the object's backing pages.

Note that we multiplex mmap_gtt and mmap_offset through the same ioctl,
and use the zero extending behaviour of drm to differentiate between
them, when we inspect the flags.

To support multiple mmap types on an object we need to support multiple
mmap_offsets for an object (each offset in the global device address
space corresponding to a unique instance of the object for a file + mmap
type). As we drop the simplified drm core idea of a single mmap_offset,
we need to provide replacement hooks for the dumb mmap interface as
well.

Link: https://gitlab.freedesktop.org/mesa/mesa/merge_requests/1675
Testcase: igt/gem_mmap_offset
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191204120032.3682839-1-chris@chris-wilson.co.uk

drm/i915: Switch obj->mm.lock lockdep annotations on its head

The trouble with having a plain nesting flag for locks which do not
naturally nest (unlike block devices and their partitions, which is
the original motivation for nesting levels) is that lockdep will
never spot a true deadlock if you screw up.

This patch is an attempt at trying better, by highlighting a bit more
of the actual nature of the nesting that's going on. Essentially we
have two kinds of objects:

- objects without pages allocated, which cannot be on any lru and are
hence inaccessible to the shrinker.

- objects which have pages allocated, which are on an lru, and which
the shrinker can decide to throw out.

For the former type of object, memory allocations while holding
obj->mm.lock are permissible. For the latter they are not. And
get/put_pages transitions between the two types of objects.

This is still not entirely fool-proof since the rules might change.
But as long as we run such a code ever at runtime lockdep should be
able to observe the inconsistency and complain (like with any other
lockdep class that we've split up in multiple classes). But there are
a few clear benefits:

- We can drop the nesting flag parameter from
__i915_gem_object_put_pages, because that function by definition is
never going allocate memory, and calling it on an object which
doesn't have its pages allocated would be a bug.

- We strictly catch more bugs, since there's not only one place in the
entire tree which is annotated with the special class. All the
other places that had explicit lockdep nesting annotations we're now
going to leave up to lockdep again.

- Specifically this catches stuff like calling get_pages from
put_pages (which isn't really a good idea, if we can call get_pages
so could the shrinker). I've seen patches do exactly that.

Of course I fully expect CI will show me for the fool I am with this
one here :-)

v2: There can only be one (lockdep only has a cache for the first
subclass, not for deeper ones, and we don't want to make these locks
even slower). Still separate enums for better documentation.

Real fix: don't forget about phys objs and pin_map(), and fix the
shrinker to have the right annotations ... silly me.

v3: Forgot usertptr too ...

v4: Improve comment for pages_pin_count, drop the IMPORTANT comment
and instead prime lockdep (Chris).

v5: Appease checkpatch, no double empty lines (Chris)

v6: More rebasing over selftest changes. Also somehow I forgot to
push this patch :-/

Also format comments consistently while at it.

v7: Fix typo in commit message (Joonas)

Also drop the priming, with the lmem merge we now have allocations
while holding the lmem lock, which wreaks the generic priming I've
done in earlier patches. Should probably be resurrected when lmem is
fixed. See

commit 232a6ebae419193f5b8da4fa869ae5089ab105c2
Author: Matthew Auld <matthew.auld@intel.com>
Date: Tue Oct 8 17:01:14 2019 +0100

drm/i915: introduce intel_memory_region

I'm keeping the priming patch locally so it wont get lost.

Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Tang, CQ" <cq.tang@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v5)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v6)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191105090148.30269-1-daniel.vetter@ffwll.ch
[mlankhorst: Fix commit typos pointed out by Michael Ruhl]

drm/i915/lmem: support kernel mapping

We can create LMEM objects, but we also need to support mapping them
into kernel space for internal use.

Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Steve Hampson <steven.t.hampson@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191025153728.23689-3-chris@chris-wilson.co.uk

drm/i915/userptr: Never allow userptr into the mappable GGTT

Daniel Vetter uncovered a nasty cycle in using the mmu-notifiers to
invalidate userptr objects which also happen to be pulled into GGTT
mmaps. That is when we unbind the userptr object (on mmu invalidation),
we revoke all CPU mmaps, which may then recurse into mmu invalidation.

We looked for ways of breaking the cycle, but the revocation on
invalidation is required and cannot be avoided. The only solution we
could see was to not allow such GGTT bindings of userptr objects in the
first place. In practice, no one really wants to use a GGTT mmapping of
a CPU pointer...

Just before Daniel's explosive lockdep patches land in v5.4-rc1, we got
a genuine blip from CI:

<4>[ 246.793958] ======================================================
<4>[ 246.793972] WARNING: possible circular locking dependency detected
<4>[ 246.793989] 5.3.0-gbd6c56f50d15-drmtip_372+ #1 Tainted: G U
<4>[ 246.794003] ------------------------------------------------------
<4>[ 246.794017] kswapd0/145 is trying to acquire lock:
<4>[ 246.794030] 000000003f565be6 (&dev->struct_mutex/1){+.+.}, at: userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[ 246.794250]
but task is already holding lock:
<4>[ 246.794263] 000000001799cef9 (&anon_vma->rwsem){++++}, at: page_lock_anon_vma_read+0xe6/0x2a0
<4>[ 246.794291]
which lock already depends on the new lock.

<4>[ 246.794307]
the existing dependency chain (in reverse order) is:
<4>[ 246.794322]
-> #3 (&anon_vma->rwsem){++++}:
<4>[ 246.794344] down_write+0x33/0x70
<4>[ 246.794357] __vma_adjust+0x3d9/0x7b0
<4>[ 246.794370] __split_vma+0x16a/0x180
<4>[ 246.794385] mprotect_fixup+0x2a5/0x320
<4>[ 246.794399] do_mprotect_pkey+0x208/0x2e0
<4>[ 246.794413] __x64_sys_mprotect+0x16/0x20
<4>[ 246.794429] do_syscall_64+0x55/0x1c0
<4>[ 246.794443] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794456]
-> #2 (&mapping->i_mmap_rwsem){++++}:
<4>[ 246.794478] down_write+0x33/0x70
<4>[ 246.794493] unmap_mapping_pages+0x48/0x130
<4>[ 246.794519] i915_vma_revoke_mmap+0x81/0x1b0 [i915]
<4>[ 246.794519] i915_vma_unbind+0x11d/0x4a0 [i915]
<4>[ 246.794519] i915_vma_destroy+0x31/0x300 [i915]
<4>[ 246.794519] __i915_gem_free_objects+0xb8/0x4b0 [i915]
<4>[ 246.794519] drm_file_free.part.0+0x1e6/0x290
<4>[ 246.794519] drm_release+0xa6/0xe0
<4>[ 246.794519] __fput+0xc2/0x250
<4>[ 246.794519] task_work_run+0x82/0xb0
<4>[ 246.794519] do_exit+0x35b/0xdb0
<4>[ 246.794519] do_group_exit+0x34/0xb0
<4>[ 246.794519] __x64_sys_exit_group+0xf/0x10
<4>[ 246.794519] do_syscall_64+0x55/0x1c0
<4>[ 246.794519] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794519]
-> #1 (&vm->mutex){+.+.}:
<4>[ 246.794519] i915_gem_shrinker_taints_mutex+0x6d/0xe0 [i915]
<4>[ 246.794519] i915_address_space_init+0x9f/0x160 [i915]
<4>[ 246.794519] i915_ggtt_init_hw+0x55/0x170 [i915]
<4>[ 246.794519] i915_driver_probe+0xc9f/0x1620 [i915]
<4>[ 246.794519] i915_pci_probe+0x43/0x1b0 [i915]
<4>[ 246.794519] pci_device_probe+0x9e/0x120
<4>[ 246.794519] really_probe+0xea/0x3d0
<4>[ 246.794519] driver_probe_device+0x10b/0x120
<4>[ 246.794519] device_driver_attach+0x4a/0x50
<4>[ 246.794519] __driver_attach+0x97/0x130
<4>[ 246.794519] bus_for_each_dev+0x74/0xc0
<4>[ 246.794519] bus_add_driver+0x13f/0x210
<4>[ 246.794519] driver_register+0x56/0xe0
<4>[ 246.794519] do_one_initcall+0x58/0x300
<4>[ 246.794519] do_init_module+0x56/0x1f6
<4>[ 246.794519] load_module+0x25bd/0x2a40
<4>[ 246.794519] __se_sys_finit_module+0xd3/0xf0
<4>[ 246.794519] do_syscall_64+0x55/0x1c0
<4>[ 246.794519] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794519]
-> #0 (&dev->struct_mutex/1){+.+.}:
<4>[ 246.794519] __lock_acquire+0x15d8/0x1e90
<4>[ 246.794519] lock_acquire+0xa6/0x1c0
<4>[ 246.794519] __mutex_lock+0x9d/0x9b0
<4>[ 246.794519] userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[ 246.794519] __mmu_notifier_invalidate_range_start+0x85/0x110
<4>[ 246.794519] try_to_unmap_one+0x76b/0x860
<4>[ 246.794519] rmap_walk_anon+0x104/0x280
<4>[ 246.794519] try_to_unmap+0xc0/0xf0
<4>[ 246.794519] shrink_page_list+0x561/0xc10
<4>[ 246.794519] shrink_inactive_list+0x220/0x440
<4>[ 246.794519] shrink_node_memcg+0x36e/0x740
<4>[ 246.794519] shrink_node+0xcb/0x490
<4>[ 246.794519] balance_pgdat+0x241/0x580
<4>[ 246.794519] kswapd+0x16c/0x530
<4>[ 246.794519] kthread+0x119/0x130
<4>[ 246.794519] ret_from_fork+0x24/0x50
<4>[ 246.794519]
other info that might help us debug this:

<4>[ 246.794519] Chain exists of:
&dev->struct_mutex/1 --> &mapping->i_mmap_rwsem --> &anon_vma->rwsem

<4>[ 246.794519] Possible unsafe locking scenario:

<4>[ 246.794519] CPU0 CPU1
<4>[ 246.794519] ---- ----
<4>[ 246.794519] lock(&anon_vma->rwsem);
<4>[ 246.794519] lock(&mapping->i_mmap_rwsem);
<4>[ 246.794519] lock(&anon_vma->rwsem);
<4>[ 246.794519] lock(&dev->struct_mutex/1);
<4>[ 246.794519]
*** DEADLOCK ***

v2: Say no to mmap_ioctl

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111744
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111870
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190928082546.3473-1-chris@chris-wilson.co.uk
(cherry picked from commit a4311745bba9763e3c965643d4531bd5765b0513)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915/region: support volatile objects

Volatile objects are marked as DONTNEED while pinned, therefore once
unpinned the backing store can be discarded. This is limited to kernel
internal objects.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008160116.18379-4-matthew.auld@intel.com

drm/i915/region: support contiguous allocations

Some kernel internal objects may need to be allocated as a contiguous
block, also thinking ahead the various kernel io_mapping interfaces seem
to expect it, although this is purely a limitation in the kernel
API...so perhaps something to be improved.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Michael J Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008160116.18379-3-matthew.auld@intel.com

drm/i915: introduce intel_memory_region

Support memory regions, as defined by a given (start, end), and allow
creating GEM objects which are backed by said region. The immediate goal
here is to have something to represent our device memory, but later on
we also want to represent every memory domain with a region, so stolen,
shmem, and of course device. At some point we are probably going to want
use a common struct here, such that we are better aligned with say TTM.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008160116.18379-2-matthew.auld@intel.com

drm/i915: Coordinate i915_active with its own mutex

Forgo the struct_mutex serialisation for i915_active, and interpose its
own mutex handling for active/retire.

This is a multi-layered sleight-of-hand. First, we had to ensure that no
active/retire callbacks accidentally inverted the mutex ordering rules,
nor assumed that they were themselves serialised by struct_mutex. More
challenging though, is the rule over updating elements of the active
rbtree. Instead of the whole i915_active now being serialised by
struct_mutex, allocations/rotations of the tree are serialised by the
i915_active.mutex and individual nodes are serialised by the caller
using the i915_timeline.mutex (we need to use nested spinlocks to
interact with the dma_fence callback lists).

The pain point here is that instead of a single mutex around execbuf, we
now have to take a mutex for active tracker (one for each vma, context,
etc) and a couple of spinlocks for each fence update. The improvement in
fine grained locking allowing for multiple concurrent clients
(eventually!) should be worth it in typical loads.

v2: Add some comments that barely elucidate anything :(

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-6-chris@chris-wilson.co.uk

drm/i915/userptr: Never allow userptr into the mappable GGTT

Daniel Vetter uncovered a nasty cycle in using the mmu-notifiers to
invalidate userptr objects which also happen to be pulled into GGTT
mmaps. That is when we unbind the userptr object (on mmu invalidation),
we revoke all CPU mmaps, which may then recurse into mmu invalidation.

We looked for ways of breaking the cycle, but the revocation on
invalidation is required and cannot be avoided. The only solution we
could see was to not allow such GGTT bindings of userptr objects in the
first place. In practice, no one really wants to use a GGTT mmapping of
a CPU pointer...

Just before Daniel's explosive lockdep patches land in v5.4-rc1, we got
a genuine blip from CI:

<4>[ 246.793958] ======================================================
<4>[ 246.793972] WARNING: possible circular locking dependency detected
<4>[ 246.793989] 5.3.0-gbd6c56f50d15-drmtip_372+ #1 Tainted: G U
<4>[ 246.794003] ------------------------------------------------------
<4>[ 246.794017] kswapd0/145 is trying to acquire lock:
<4>[ 246.794030] 000000003f565be6 (&dev->struct_mutex/1){+.+.}, at: userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[ 246.794250]
but task is already holding lock:
<4>[ 246.794263] 000000001799cef9 (&anon_vma->rwsem){++++}, at: page_lock_anon_vma_read+0xe6/0x2a0
<4>[ 246.794291]
which lock already depends on the new lock.

<4>[ 246.794307]
the existing dependency chain (in reverse order) is:
<4>[ 246.794322]
-> #3 (&anon_vma->rwsem){++++}:
<4>[ 246.794344] down_write+0x33/0x70
<4>[ 246.794357] __vma_adjust+0x3d9/0x7b0
<4>[ 246.794370] __split_vma+0x16a/0x180
<4>[ 246.794385] mprotect_fixup+0x2a5/0x320
<4>[ 246.794399] do_mprotect_pkey+0x208/0x2e0
<4>[ 246.794413] __x64_sys_mprotect+0x16/0x20
<4>[ 246.794429] do_syscall_64+0x55/0x1c0
<4>[ 246.794443] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794456]
-> #2 (&mapping->i_mmap_rwsem){++++}:
<4>[ 246.794478] down_write+0x33/0x70
<4>[ 246.794493] unmap_mapping_pages+0x48/0x130
<4>[ 246.794519] i915_vma_revoke_mmap+0x81/0x1b0 [i915]
<4>[ 246.794519] i915_vma_unbind+0x11d/0x4a0 [i915]
<4>[ 246.794519] i915_vma_destroy+0x31/0x300 [i915]
<4>[ 246.794519] __i915_gem_free_objects+0xb8/0x4b0 [i915]
<4>[ 246.794519] drm_file_free.part.0+0x1e6/0x290
<4>[ 246.794519] drm_release+0xa6/0xe0
<4>[ 246.794519] __fput+0xc2/0x250
<4>[ 246.794519] task_work_run+0x82/0xb0
<4>[ 246.794519] do_exit+0x35b/0xdb0
<4>[ 246.794519] do_group_exit+0x34/0xb0
<4>[ 246.794519] __x64_sys_exit_group+0xf/0x10
<4>[ 246.794519] do_syscall_64+0x55/0x1c0
<4>[ 246.794519] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794519]
-> #1 (&vm->mutex){+.+.}:
<4>[ 246.794519] i915_gem_shrinker_taints_mutex+0x6d/0xe0 [i915]
<4>[ 246.794519] i915_address_space_init+0x9f/0x160 [i915]
<4>[ 246.794519] i915_ggtt_init_hw+0x55/0x170 [i915]
<4>[ 246.794519] i915_driver_probe+0xc9f/0x1620 [i915]
<4>[ 246.794519] i915_pci_probe+0x43/0x1b0 [i915]
<4>[ 246.794519] pci_device_probe+0x9e/0x120
<4>[ 246.794519] really_probe+0xea/0x3d0
<4>[ 246.794519] driver_probe_device+0x10b/0x120
<4>[ 246.794519] device_driver_attach+0x4a/0x50
<4>[ 246.794519] __driver_attach+0x97/0x130
<4>[ 246.794519] bus_for_each_dev+0x74/0xc0
<4>[ 246.794519] bus_add_driver+0x13f/0x210
<4>[ 246.794519] driver_register+0x56/0xe0
<4>[ 246.794519] do_one_initcall+0x58/0x300
<4>[ 246.794519] do_init_module+0x56/0x1f6
<4>[ 246.794519] load_module+0x25bd/0x2a40
<4>[ 246.794519] __se_sys_finit_module+0xd3/0xf0
<4>[ 246.794519] do_syscall_64+0x55/0x1c0
<4>[ 246.794519] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[ 246.794519]
-> #0 (&dev->struct_mutex/1){+.+.}:
<4>[ 246.794519] __lock_acquire+0x15d8/0x1e90
<4>[ 246.794519] lock_acquire+0xa6/0x1c0
<4>[ 246.794519] __mutex_lock+0x9d/0x9b0
<4>[ 246.794519] userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[ 246.794519] __mmu_notifier_invalidate_range_start+0x85/0x110
<4>[ 246.794519] try_to_unmap_one+0x76b/0x860
<4>[ 246.794519] rmap_walk_anon+0x104/0x280
<4>[ 246.794519] try_to_unmap+0xc0/0xf0
<4>[ 246.794519] shrink_page_list+0x561/0xc10
<4>[ 246.794519] shrink_inactive_list+0x220/0x440
<4>[ 246.794519] shrink_node_memcg+0x36e/0x740
<4>[ 246.794519] shrink_node+0xcb/0x490
<4>[ 246.794519] balance_pgdat+0x241/0x580
<4>[ 246.794519] kswapd+0x16c/0x530
<4>[ 246.794519] kthread+0x119/0x130
<4>[ 246.794519] ret_from_fork+0x24/0x50
<4>[ 246.794519]
other info that might help us debug this:

<4>[ 246.794519] Chain exists of:
&dev->struct_mutex/1 --> &mapping->i_mmap_rwsem --> &anon_vma->rwsem

<4>[ 246.794519] Possible unsafe locking scenario:

<4>[ 246.794519] CPU0 CPU1
<4>[ 246.794519] ---- ----
<4>[ 246.794519] lock(&anon_vma->rwsem);
<4>[ 246.794519] lock(&mapping->i_mmap_rwsem);
<4>[ 246.794519] lock(&anon_vma->rwsem);
<4>[ 246.794519] lock(&dev->struct_mutex/1);
<4>[ 246.794519]
*** DEADLOCK ***

v2: Say no to mmap_ioctl

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111744
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111870
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190928082546.3473-1-chris@chris-wilson.co.uk

drm/i915: Make shrink/unshrink be atomic

Add an atomic counter and always take the spinlock around the pin/unpin
events, so that we can perform the list manipulation concurrently.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190910212204.17190-1-chris@chris-wilson.co.uk

drm/i915: include GTT page-size info in error state

It might prove useful in the future to know if the vma is utilising
huge-GTT-pages. Related to this is the GTT cache, where there is some HW
"quirkiness" where it must be disabled if using 2M pages, so include
that for good measure.

Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190909171646.22090-1-matthew.auld@intel.com

drm/i915: Replace obj->pin_global with obj->frontbuffer

obj->pin_global was originally used as a means to keep the shrinker off
the active scanout, but we use the vma->pin_count itself for that and
the obj->frontbuffer to delay shrinking active framebuffers. The other
role that obj->pin_global gained was for spotting display objects inside
GEM and working harder to keep those coherent; for which we can again
simply inspect obj->frontbuffer directly.

Coming up next, we will want to manipulate the pin_global counter
outside of the principle locks, so would need to make pin_global atomic.
However, since obj->frontbuffer is already managed atomically, it makes
sense to use that the primary key for display objects instead of having
pin_global.

Ville pointed out the principle difference is that obj->frontbuffer is
set for as long as an intel_framebuffer is attached to an object, but
obj->pin_global was only raised for as long as the object was active. In
practice, this means that we consider the object as being on the scanout
for longer than is strictly required, causing us to be more proactive in
flushing -- though it should be true that we would have flushed
eventually when the back became the front, except that on the flip path
that flush is async but when hit from another ioctl it will be
synchronous.

v2: i915_gem_object_is_framebuffer()

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190902040303.14195-5-chris@chris-wilson.co.uk

drm/i915: Extract intel_frontbuffer active tracking

Move the active tracking for the frontbuffer operations out of the
i915_gem_object and into its own first class (refcounted) object. In the
process of detangling, we switch from low level request tracking to the
easier i915_active -- with the plan that this avoids any potential
atomic callbacks as the frontbuffer tracking wishes to sleep as it
flushes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190816074635.26062-1-chris@chris-wilson.co.uk

drm/i915: Replace struct_mutex for batch pool serialisation

Switch to tracking activity via i915_active on individual nodes, only
keeping a list of retired objects in the cache, and reaping the cache
when the engine itself idles.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190804124826.30272-2-chris@chris-wilson.co.uk

drm/i915: Throw away the active object retirement complexity

Remove the accumulated optimisations that we have for i915_vma_retire
and reduce it to the bare essential of tracking the active object
reference. This allows us to only use atomic operations, and so will be
able to avoid the struct_mutex requirement.

The principal loss here is the shrinker MRU bumping, so now if we have
to shrink, we will do so in much more random order and more likely to
try and shrink recently used objects. That is a nuisance, but shrinking
active objects is a second step we try to avoid and will always be a
system-wide performance issue.

The other loss is here is in the automatic pruning of the
reservation_object when idling. This is not as large an issue as upon
reservation_object introduction as now adding new fences into the object
replaces already signaled fences, keeping the array compact. But we do
lose the auto-expiration of stale fences and unused arrays. That may be
a noticeable problem for which we need to re-implement autopruning.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621183801.23252-3-chris@chris-wilson.co.uk

drm/i915: Use drm_gem_object.resv

Since commit 1ba627148ef5 ("drm: Add reservation_object to
drm_gem_object"), struct drm_gem_object grew its own builtin
reservation_object rendering our own private one bloat. Remove our
redundant reservation_object and point into obj->base.resv instead.

References: 1ba627148ef5 ("drm: Add reservation_object to drm_gem_object")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190618125858.7295-1-chris@chris-wilson.co.uk

drm/i915: Combine unbound/bound list tracking for objects

With async binding, we don't want to manage a bound/unbound list as we
may end up running before we even acquire the pages. All that is
required is keeping track of shrinkable objects, so reduce it to the
minimum list.

Fixes: 6951e5893b48 ("drm/i915: Move GEM object domain management from struct_mutex to local")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190612105720.30310-1-chris@chris-wilson.co.uk

drm/i915: Move object close under its own lock

Use i915_gem_object_lock() to guard the LUT and active reference to
allow us to break free of struct_mutex for handling GEM_CLOSE.

Testcase: igt/gem_close_race
Testcase: igt/gem_exec_parallel
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190606112320.9704-1-chris@chris-wilson.co.uk

drm/i915: Drop the deferred active reference

An old optimisation to reduce the number of atomics per batch sadly
relies on struct_mutex for coordination. In order to remove struct_mutex
from serialising object/context closing, always taking and releasing an
active reference on first use / last use greatly simplifies the locking.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-15-chris@chris-wilson.co.uk

drm/i915: Move phys objects to its own file

Continuing the decluttering of i915_gem.c, this time the legacy physical
object.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-5-chris@chris-wilson.co.uk

drm/i915: Split GEM object type definition to its own header

For convenience in avoiding inline spaghetti, keep the type definition
as a separate header.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-1-chris@chris-wilson.co.uk