It's unclear what reference the initial vma kref reference refers to.
A vma can have multiple weak references, the object vma list,
the vm's bound list and the GT's closed_list, and the initial vma
reference can be put from lookups of all these lists.
With the current implementation this means
that any holder of yet another vma refcount (currently only
i915_gem_object_unbind()) needs to be holding two of either
*) An object refcount,
*) A vm open count
*) A vma open count
in order for us to not risk leaking a reference by having the
initial vma reference being put twice.
Address this by re-introducing i915_vma_destroy() which removes all
weak references of the vma and *then* puts the initial vma refcount.
This makes a strong vma reference hold on to the vma unconditionally.
Perhaps a better name would be i915_vma_revoke() or i915_vma_zombify(),
since other callers may still hold a refcount, but with the prospect of
being able to replace the vma refcount with the object lock in the near
future, let's stick with i915_vma_destroy().
Finally this commit fixes a race in that previously i915_vma_release() and
now i915_vma_destroy() could destroy a vma without taking the vm->mutex
after an advisory check that the vma mm_node was not allocated.
This would race with the ungrab_vma() function creating a trace similar
to the below one. This was fixed in one of the __i915_vma_put() callsites
in
commit bc1922e5d3 ("drm/i915: Fix a race between vma / object destruction and unbinding")
but although not seemingly triggered by CI, that
is not sufficient. This patch is needed to fix that properly.
[823.012188] Console: switching to colour dummy device 80x25
[823.012422] [IGT] gem_ppgtt: executing
[823.016667] [IGT] gem_ppgtt: starting subtest blt-vs-render-ctx0
[852.436465] stack segment: 0000 [#1] PREEMPT SMP NOPTI
[852.436480] CPU: 0 PID: 3200 Comm: gem_ppgtt Not tainted 5.16.0-CI-CI_DRM_11115+ #1
[852.436489] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR5 RVP, BIOS ADLPFWI1.R00.2422.A00.2110131104 10/13/2021
[852.436499] RIP: 0010:ungrab_vma+0x9/0x80 [i915]
[852.436711] Code: ef e8 4b 85 cf e0 e8 36 a3 d6 e0 8b 83 f8 9c 00 00 85 c0 75 e1 5b 5d 41 5c 41 5d c3 e9 d6 fd 14 00 55 53 48 8b af c0 00 00 00 <8b> 45 00 85 c0 75 03 5b 5d c3 48 8b 85 a0 02 00 00 48 89 fb 48 8b
[852.436727] RSP: 0018:ffffc90006db7880 EFLAGS: 00010246
[852.436734] RAX: 0000000000000000 RBX: ffffc90006db7598 RCX: 0000000000000000
[852.436742] RDX: ffff88815349e898 RSI: ffff88815349e858 RDI: ffff88810a284140
[852.436748] RBP: 6b6b6b6b6b6b6b6b R08: ffff88815349e898 R09: ffff88815349e8e8
[852.436754] R10: 0000000000000001 R11: 0000000051ef1141 R12: ffff88810a284140
[852.436762] R13: 0000000000000000 R14: ffff88815349e868 R15: ffff88810a284458
[852.436770] FS: 00007f5c04b04e40(0000) GS:ffff88849f000000(0000) knlGS:0000000000000000
[852.436781] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[852.436788] CR2: 00007f5c04b38fe0 CR3: 000000010a6e8001 CR4: 0000000000770ef0
[852.436797] PKRU: 55555554
[852.436801] Call Trace:
[852.436806] <TASK>
[852.436811] i915_gem_evict_for_node+0x33c/0x3c0 [i915]
[852.437014] i915_gem_gtt_reserve+0x106/0x130 [i915]
[852.437211] i915_vma_pin_ww+0x8f4/0xb60 [i915]
[852.437412] eb_validate_vmas+0x688/0x860 [i915]
[852.437596] i915_gem_do_execbuffer+0xc0e/0x25b0 [i915]
[852.437770] ? deactivate_slab+0x5f2/0x7d0
[852.437778] ? _raw_spin_unlock_irqrestore+0x50/0x60
[852.437789] ? i915_gem_execbuffer2_ioctl+0xc6/0x2c0 [i915]
[852.437944] ? init_object+0x49/0x80
[852.437950] ? __lock_acquire+0x5e6/0x2580
[852.437963] i915_gem_execbuffer2_ioctl+0x116/0x2c0 [i915]
[852.438129] ? i915_gem_do_execbuffer+0x25b0/0x25b0 [i915]
[852.438300] drm_ioctl_kernel+0xac/0x140
[852.438310] drm_ioctl+0x201/0x3d0
[852.438316] ? i915_gem_do_execbuffer+0x25b0/0x25b0 [i915]
[852.438490] __x64_sys_ioctl+0x6a/0xa0
[852.438498] do_syscall_64+0x37/0xb0
[852.438507] entry_SYSCALL_64_after_hwframe+0x44/0xae
[852.438515] RIP: 0033:0x7f5c0415b317
[852.438523] Code: b3 66 90 48 8b 05 71 4b 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 4b 2d 00 f7 d8 64 89 01 48
[852.438542] RSP: 002b:00007ffd765039a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[852.438553] RAX: ffffffffffffffda RBX: 000055e4d7829dd0 RCX: 00007f5c0415b317
[852.438562] RDX: 00007ffd76503a00 RSI: 00000000c0406469 RDI: 0000000000000017
[852.438571] RBP: 00007ffd76503a00 R08: 0000000000000000 R09: 0000000000000081
[852.438579] R10: 00000000ffffff7f R11: 0000000000000246 R12: 00000000c0406469
[852.438587] R13: 0000000000000017 R14: 00007ffd76503a00 R15: 0000000000000000
[852.438598] </TASK>
[852.438602] Modules linked in: snd_hda_codec_hdmi i915 mei_hdcp x86_pkg_temp_thermal snd_hda_intel snd_intel_dspcfg drm_buddy coretemp crct10dif_pclmul crc32_pclmul snd_hda_codec ttm ghash_clmulni_intel snd_hwdep snd_hda_core e1000e drm_dp_helper ptp snd_pcm mei_me drm_kms_helper pps_core mei syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers intel_lpss_pci smsc75xx usbnet mii
[852.440310] ---[ end trace e52cdd2fe4fd911c ]---
v2: Fix typos in the commit message.
Fixes: 7e00897be8 ("drm/i915: Add object locking to i915_gem_evict_for_node and i915_gem_evict_something, v2.")
Fixes: bc1922e5d3 ("drm/i915: Fix a race between vma / object destruction and unbinding")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.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/20220222133209.587978-1-thomas.hellstrom@linux.intel.com
UAPI Changes:
- Weak parallel submission support for execlists
Minimal implementation of the parallel submission support for
execlists backend that was previously only implemented for GuC.
Support one sibling non-virtual engine.
Core Changes:
- Two backmerges of drm/drm-next for header file renames/changes and
i915_regs reorganization
Driver Changes:
- Add new DG2 subplatform: DG2-G12 (Matt R)
- Add new DG2 workarounds (Matt R, Ram, Bruce)
- Handle pre-programmed WOPCM registers for DG2+ (Daniele)
- Update guc shim control programming on XeHP SDV+ (Daniele)
- Add RPL-S C0/D0 stepping information (Anusha)
- Improve GuC ADS initialization to work on ARM64 on dGFX (Lucas)
- Fix KMD and GuC race on accessing PMU busyness (Umesh)
- Use PM timestamp instead of RING TIMESTAMP for reference in PMU with GuC (Umesh)
- Report error on invalid reset notification from GuC (John)
- Avoid WARN splat by holding RPM wakelock during PXP unbind (Juston)
- Fixes to parallel submission implementation (Matt B.)
- Improve GuC loading status check/error reports (John)
- Tweak TTM LRU priority hint selection (Matt A.)
- Align the plane_vma to min_page_size of stolen mem (Ram)
- Introduce vma resources and implement async unbinding (Thomas)
- Use struct vma_resource instead of struct vma_snapshot (Thomas)
- Return some TTM accel move errors instead of trying memcpy move (Thomas)
- Fix a race between vma / object destruction and unbinding (Thomas)
- Remove short-term pins from execbuf (Maarten)
- Update to GuC version 69.0.3 (John, Michal Wa.)
- Improvements to GT reset paths in GuC backend (Matt B.)
- Use shrinker_release_pages instead of writeback in shmem object hooks (Matt A., Tvrtko)
- Use trylock instead of blocking lock when freeing GEM objects (Maarten)
- Allocate intel_engine_coredump_alloc with ALLOW_FAIL (Matt B.)
- Fixes to object unmapping and purging (Matt A)
- Check for wedged device in GuC backend (John)
- Avoid lockdep splat by locking dpt_obj around set_cache_level (Maarten)
- Allow dead vm to unbind vma's without lock (Maarten)
- s/engine->i915/i915/ for DG2 engine workarounds (Matt R)
- Use to_gt() helper for GGTT accesses (Michal Wi.)
- Selftest improvements (Matt B., Thomas, Ram)
- Coding style and compiler warning fixes (Matt B., Jasmine, Andi, Colin, Gustavo, Dan)
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Yg4i2aCZvvee5Eai@jlahtine-mobl.ger.corp.intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[Fixed conflicts while applying, using the fixups/drm-intel-gt-next.patch
from drm-rerere's 1f2b1742abdd ("2022y-02m-23d-16h-07m-57s UTC: drm-tip
rerere cache update")]
For local-memory objects we need to align the GTT addresses
to 64K, both for the ppgtt and ggtt.
We need to support vm->min_alignment > 4K, depending
on the vm itself and the type of object we are inserting.
With this in mind update the GTT selftests to take this
into account.
For compact-pt we further align and pad lmem object GTT addresses
to 2MB to ensure PDEs contain consistent page sizes as
required by the HW.
v3:
* use needs_compact_pt flag to discriminate between
64K and 64K with compact-pt
* add i915_vm_obj_min_alignment
* use i915_vm_obj_min_alignment to round up vma reservation
if compact-pt instead of hard coding
v5:
* fix i915_vm_obj_min_alignment for internal objects which
have no memory region
v6:
* tiled_blits_create correctly pick largest required alignment
v8:
* i915_vm_min_alignment protect against array overflow for mock region
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220218184752.7524-7-ramalingam.c@intel.com
Rename struct dma_buf_map to struct iosys_map and corresponding APIs.
Over time dma-buf-map grew up to more functionality than the one used by
dma-buf: in fact it's just a shim layer to abstract system memory, that
can be accessed via regular load and store, from IO memory that needs to
be acessed via arch helpers.
The idea is to extend this API so it can fulfill other needs, internal
to a single driver. Example: in the i915 driver it's desired to share
the implementation for integrated graphics, which uses mostly system
memory, with discrete graphics, which may need to access IO memory.
The conversion was mostly done with the following semantic patch:
@r1@
@@
- struct dma_buf_map
+ struct iosys_map
@r2@
@@
(
- DMA_BUF_MAP_INIT_VADDR
+ IOSYS_MAP_INIT_VADDR
|
- dma_buf_map_set_vaddr
+ iosys_map_set_vaddr
|
- dma_buf_map_set_vaddr_iomem
+ iosys_map_set_vaddr_iomem
|
- dma_buf_map_is_equal
+ iosys_map_is_equal
|
- dma_buf_map_is_null
+ iosys_map_is_null
|
- dma_buf_map_is_set
+ iosys_map_is_set
|
- dma_buf_map_clear
+ iosys_map_clear
|
- dma_buf_map_memcpy_to
+ iosys_map_memcpy_to
|
- dma_buf_map_incr
+ iosys_map_incr
)
@@
@@
- #include <linux/dma-buf-map.h>
+ #include <linux/iosys-map.h>
Then some files had their includes adjusted and some comments were
update to remove mentions to dma-buf-map.
Since this is not specific to dma-buf anymore, move the documentation to
the "Bus-Independent Device Accesses" section.
v2:
- Squash patches
v3:
- Fix wrong removal of dma-buf.h from MAINTAINERS
- Move documentation from dma-buf.rst to device-io.rst
v4:
- Change documentation title and level
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
We want to remove more members of i915_vma, which requires the locking to
be held more often.
Start requiring gem object lock for i915_vma_unbind, as it's one of the
callers that may unpin pages.
Some special care is needed when evicting, because the last reference to
the object may be held by the VMA, so after __i915_vma_unbind, vma may be
garbage, and we need to cache vma->obj before unlocking.
Changes since v1:
- Make trylock failing a WARN. (Matt)
- Remove double i915_vma_wait_for_bind() (Matt)
- Move atomic_set to right before mutex_unlock(), to make it more clear
they belong together. (Matt)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114132320.109030-5-maarten.lankhorst@linux.intel.com
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
There is an interesting refcounting loop:
struct intel_memory_region has a struct ttm_resource_manager,
ttm_resource_manager->move may hold a reference to i915_request,
i915_request may hold a reference to intel_context,
intel_context may hold a reference to drm_i915_gem_object,
drm_i915_gem_object may hold a reference to intel_memory_region.
Break this loop by dropping region reference counting.
In addition, Have regions with a manager moving fence make sure
that all region objects are released before freeing the region.
v6:
- Fix a code comment.
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/20211122214554.371864-4-thomas.hellstrom@linux.intel.com
If the initial fill blit or copy blit of an object fails, the old
content of the data might be exposed and read as soon as either CPU- or
GPU PTEs are set up to point at the pages.
Intercept the blit fence with an async callback that checks the
blit fence for errors and if there are errors performs an async cpu blit
instead. If there is a failure to allocate the async dma_fence_work,
allocate it on the stack and sync wait for the blit to complete.
Add selftests that simulate gpu blit failures and failure to allocate
the async dma_fence_work.
A previous version of this pach used dma_fence_work, now that's
opencoded which adds more code but might lower the latency
somewhat in the common non-error case.
v3:
- Style fixes (Matthew Auld)
v4:
- Use "#if IS_ENABLED()" instead of #ifdef (Matthew Auld)
v5:
- Fix an issue where we, if the dependency was already signaled, might
end up waiting for a memcpy fence that would never signal.
v6:
- Add a missing i915_ttm_memcpy_release() (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/20211104110718.688420-3-thomas.hellstrom@linux.intel.com
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
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
Clang warns:
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:13: warning:
variable 'err' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
} else if (PTR_ERR(import) != -EOPNOTSUPP) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:138:9: note:
uninitialized use occurs here
return err;
^~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:127:9: note: remove
the 'if' if its condition is always true
} else if (PTR_ERR(import) != -EOPNOTSUPP) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:95:9: note:
initialize the variable 'err' to silence this warning
int err;
^
= 0
The test is expected to pass if i915_gem_prime_import() returns
-EOPNOTSUPP so initialize err to zero in this case.
Fixes: cdb35d1ed6 ("drm/i915/gem: Migrate to system at dma-buf attach time (v7)")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824225427.2065517-3-nathan@kernel.org
Clang warns a couple of times:
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:63:6: warning:
variable 'import_obj' is used uninitialized whenever 'if' condition is
true [-Wsometimes-uninitialized]
if (import != &obj->base) {
^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:80:22: note:
uninitialized use occurs here
i915_gem_object_put(import_obj);
^~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:63:2: note: remove
the 'if' if its condition is always false
if (import != &obj->base) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c:38:46: note:
initialize the variable 'import_obj' to silence this warning
struct drm_i915_gem_object *obj, *import_obj;
^
= NULL
Shuffle the import_obj initialization above these if statements so that
it is not used uninitialized.
Fixes: d7b2cb380b ("drm/i915/gem: Correct the locking and pin pattern for dma-buf (v8)")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824225427.2065517-2-nathan@kernel.org
It's been invariant since
commit ccbc1b9794
Author: Jason Ekstrand <jason@jlekstrand.net>
Date: Thu Jul 8 10:48:30 2021 -0500
drm/i915/gem: Don't allow changing the VM on running contexts (v4)
this just completes the deed. I've tried to split out prep work for
more careful review as much as possible, this is what's left:
- get_ppgtt gets simplified since we don't need to grab a temporary
reference - we can rely on the temporary reference for the gem_ctx
while we inspect the vm. The new vm_id still needs a full
i915_vm_open ofc. This also removes the final caller of context_get_vm_rcu
- A pile of selftests can now just look at ctx->vm instead of
rcu_dereference_protected( , true) or similar things.
- All callers of i915_gem_context_vm also disappear.
- I've changed the hugepage selftest to set scrub_64K without any
locking, because when we inspect that setting we're also not taking
any locks either. It works because it's a selftests that's careful
(single threaded gives you nice ordering) and not a live driver
where races can happen from anywhere.
These can only be split up further if we have some intermediate state
with a bunch more rcu_dereference_protected(ctx->vm, true), just to
shut up lockdep and sparse.
The conversion to __rcu happened in
commit a4e7ccdac3
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri Oct 4 14:40:09 2019 +0100
drm/i915: Move context management under GEM
Note that we're not breaking the actual bugfix in there: The real
bugfix is pushing the i915_vm_relase onto a separate worker, to avoid
locking inversion issues. The rcu conversion was just thrown in for
entertainment value on top (no vm lookup isn't even close to anything
that's a hotpath where removing the single spinlock can be measured).
v2: Rebase over the change to move the i915_vm_put() into
i915_gem_context_release().
v3: Trivial conflict against repainted shed.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902142057.929669-9-daniel.vetter@ffwll.ch
Using the I915_MMAP_TYPE_FIXED mmap type requires the TTM backend, so
for that mmap type, use __i915_gem_object_create_user() instead of
i915_gem_object_create_internal(), as we really want to tests objects
mmap-able by user-space.
This also means that the out-of-space error happens at object creation
and returns -ENXIO rather than -ENOSPC, so fix the code up to expect
that on out-of-offset-space errors.
Finally only use I915_MMAP_TYPE_FIXED for LMEM and SMEM for now if
testing on LMEM-capable devices. For stolen LMEM, we still take the
same path as for integrated, as that haven't been moved over to TTM yet,
and user-space should not be able to create out of stolen LMEM anyway.
v2:
- Check the presence of the obj->ops->mmap_offset callback rather than
hardcoding the supported mmap regions in can_mmap() (Maarten Lankhorst)
Fixes: 7961c5b60f ("drm/i915: Add TTM offset argument to mmap.")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210831122931.157536-1-thomas.hellstrom@linux.intel.com
Until we support p2p dma or as a complement to that, migrate data
to system memory at dma-buf attach time if possible.
v2:
- Rebase on dynamic exporter. Update the igt_dmabuf_import_same_driver
selftest to migrate if we are LMEM capable.
v3:
- Migrate also in the pin() callback.
v4:
- Migrate in attach
v5: (jason)
- Lock around the migration
v6: (jason)
- Move the can_migrate check outside the lock
- Rework the selftests to test more migration conditions. In
particular, SMEM, LMEM, and LMEM+SMEM are all checked.
v7: (mauld)
- Misc style nits
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723172142.3273510-9-jason@jlekstrand.net
If our exported dma-bufs are imported by another instance of our driver,
that instance will typically have the imported dma-bufs locked during
dma_buf_map_attachment(). But the exporter also locks the same reservation
object in the map_dma_buf() callback, which leads to recursive locking.
So taking the lock inside _pin_pages_unlocked() is incorrect.
Additionally, the current pinning code path is contrary to the defined
way that pinning should occur.
Remove the explicit pin/unpin from the map/umap functions and move them
to the attach/detach allowing correct locking to occur, and to match
the static dma-buf drm_prime pattern.
Add a live selftest to exercise both dynamic and non-dynamic
exports.
v2:
- Extend the selftest with a fake dynamic importer.
- Provide real pin and unpin callbacks to not abuse the interface.
v3: (ruhl)
- Remove the dynamic export support and move the pinning into the
attach/detach path.
v4: (ruhl)
- Put pages does not need to assert on the dma-resv
v5: (jason)
- Lock around dma_buf_unmap_attachment() when emulating a dynamic
importer in the subtests.
- Use pin_pages_unlocked
v6: (jason)
- Use dma_buf_attach instead of dma_buf_attach_dynamic in the selftests
v7: (mauld)
- Use __i915_gem_object_get_pages (2 __underscores) instead of the
4 ____underscore version in the selftests
v8: (mauld)
- Drop the kernel doc from the static i915_gem_dmabuf_attach function
- Add missing "err = PTR_ERR()" to a bunch of selftest error cases
Reported-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723172142.3273510-8-jason@jlekstrand.net
We don't roll them together entirely because there are still a couple
cases where we want a separate can_migrate check. For instance, the
display code checks that you can migrate a buffer to LMEM before it
accepts it in fb_create. The dma-buf import code also uses it to do an
early check and return a different error code if someone tries to attach
a LMEM-only dma-buf to another driver.
However, no one actually wants to call object_migrate when can_migrate
has failed. The stated intention is for self-tests but none of those
actually take advantage of this unsafe migration.
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723172142.3273510-2-jason@jlekstrand.net
This reverts 686c7c35ab ("drm/i915/gem: Asynchronous cmdparser"). The
justification for this commit in the git history was a vague comment
about getting it out from under the struct_mutex. While this may
improve perf for some workloads on Gen7 platforms where we rely on the
command parser for features such as indirect rendering, no numbers were
provided to prove such an improvement. It claims to closed two
gitlab/bugzilla issues but with no explanation whatsoever as to why or
what bug it's fixing.
Meanwhile, by moving command parsing off to an async callback, it leaves
us with a problem of what to do on error. When things were synchronous,
EXECBUFFER2 would fail with an error code if parsing failed. When
moving it to async, we needed another way to handle that error and the
solution employed was to set an error on the dma_fence and then trust
that said error gets propagated to the client eventually. Moving back
to synchronous will help us untangle the fence error propagation mess.
This also reverts most of 0edbb9ba1b ("drm/i915: Move cmd parser
pinning to execbuffer") which is a refactor of some of our allocation
paths for asynchronous parsing. Now that everything is synchronous, we
don't need it.
v2 (Daniel Vetter):
- Add stabel Cc and Fixes tag
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: <stable@vger.kernel.org> # v5.6+
Fixes: 9e31c1fe45 ("drm/i915: Propagate errors on awaiting already signaled fences")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Jon Bloomfield <jon.bloomfield@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714193419.1459723-2-jason@jlekstrand.net
