With the introduction of ctx->engines[] we allow multiple logical
contexts to be used on the same engine (e.g. with virtual engines).
According to bspec, aach logical context requires a unique tag in order
for context-switching to occur correctly between them. [Simple
experiments show that it is not so easy to trick the HW into performing
a lite-restore with matching logical IDs, though my memory from early
Broadwell experiments do suggest that it should be generating
lite-restores.]
We only need to keep a unique tag for the active lifetime of the
context, and for as long as we need to identify that context. The HW
uses the tag to determine if it should use a lite-restore (why not the
LRCA?) and passes the tag back for various status identifies. The only
status we need to track is for OA, so when using perf, we assign the
specific context a unique tag.
v2: Calculate required number of tags to fill ELSP.
Fixes: 976b55f0e1 ("drm/i915: Allow a context to define its set of engines")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111895
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-14-chris@chris-wilson.co.uk
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
Replace the struct_mutex requirement for pinning the i915_vma with the
local vm->mutex instead. Note that the vm->mutex is tainted by the
shrinker (we require unbinding from inside fs-reclaim) and so we cannot
allocate while holding that mutex. Instead we have to preallocate
workers to do allocate and apply the PTE updates after we have we
reserved their slot in the drm_mm (using fences to order the PTE writes
with the GPU work and with later unbind).
In adding the asynchronous vma binding, one subtle requirement is to
avoid coupling the binding fence into the backing object->resv. That is
the asynchronous binding only applies to the vma timeline itself and not
to the pages as that is a more global timeline (the binding of one vma
does not need to be ordered with another vma, nor does the implicit GEM
fencing depend on a vma, only on writes to the backing store). Keeping
the vma binding distinct from the backing store timelines is verified by
a number of async gem_exec_fence and gem_exec_schedule tests. The way we
do this is quite simple, we keep the fence for the vma binding separate
and only wait on it as required, and never add it to the obj->resv
itself.
Another consequence in reducing the locking around the vma is the
destruction of the vma is no longer globally serialised by struct_mutex.
A natural solution would be to add a kref to i915_vma, but that requires
decoupling the reference cycles, possibly by introducing a new
i915_mm_pages object that is own by both obj->mm and vma->pages.
However, we have not taken that route due to the overshadowing lmem/ttm
discussions, and instead play a series of complicated games with
trylocks to (hopefully) ensure that only one destruction path is called!
v2: Add some commentary, and some helpers to reduce patch churn.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-4-chris@chris-wilson.co.uk
Since we cannot allocate underneath the vm->mutex (it is used in the
direct-reclaim paths), we need to shift the allocations off into a
mutexless worker with fence recursion prevention. To know when we need
this protection, we mark up the address spaces that do allocate before
insertion. In the future, we may wish to extend the async bind scheme to
more than just allocations.
v2: s/vm->bind_alloc/vm->bind_async_flags/
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-3-chris@chris-wilson.co.uk
There is a return statement that is not reachable and a variable that
is not used. Remove them.
Addresses-Coverity: ("Structurally dead code")
Fixes: de7b45babd ("drm/amdgpu: cleanup creating BOs at fixed location (v2)")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
The boolean variable pasid_mapping_needed is not initialized and
there are code paths that do not assign it any value before it is
is read later. Fix this by initializing pasid_mapping_needed to
false.
Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 6817bf283b ("drm/amdgpu: grab the id mgr lock while accessing passid_mapping")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Fix sparse warnings:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_hdcp.c:32:6: warning: symbol 'lp_write_i2c' was not declared. Should it be static?
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_hdcp.c:42:6: warning: symbol 'lp_read_i2c' was not declared. Should it be static?
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_hdcp.c:52:6: warning: symbol 'lp_write_dpcd' was not declared. Should it be static?
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_hdcp.c:59:6: warning: symbol 'lp_read_dpcd' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
A few callers need to serialise the destruction of their drm_mm_node and
ensure it is removed from the drm_mm before freeing. However, to be
completely sure that any access from another thread is complete before
we free the struct, we require the RELEASE semantics of
clear_bit_unlock().
This allows the conditional locking such as
Thread A Thread B
mutex_lock(mm_lock); if (drm_mm_node_allocated(node)) {
drm_mm_node_remove(node); mutex_lock(mm_lock);
mutex_unlock(mm_lock); if (drm_mm_node_allocated(node))
drm_mm_node_remove(node);
mutex_unlock(mm_lock);
}
kfree(node);
to serialise correctly without any lingering accesses from A to the
freed node. Allocation / insertion of the node is assumed never to race
with removal or eviction scanning.
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/20191003210100.22250-5-chris@chris-wilson.co.uk
By putting cursor BOs at the high end of the video memory, we can avoid
memory fragmentation. Starting at the low end, contiguous video memory is
available for framebuffers.
The patch also simplifies the buffer swapping and aligns it with the
ast driver. If there are more drivers with similar requirements, the
code could be moved into a shared place.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190927091301.10574-8-tzimmermann@suse.de
The double-buffered cursor image is currently stored in video memory
by creating two BOs and pinning them to VRAM. The exact location is
chosen by VRAM helpers. The pinned cursor BOs can conflict with
framebuffer BOs and prevent the primary plane from displaying its
framebuffer.
As a first step to solving this problem, we reserve dedicated space at
the high end of the video memory for the cursor images. As the amount
of video memory now differs from the amount of available framebuffer
memory, size tests are adapted accordingly.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190927091301.10574-7-tzimmermann@suse.de
Separating the management of buffer objects from updating the hardware
cursor buffer gives the code more structure. While doing this, we can
further split the image-update code into code for writing the buffer,
setting the base scan-out address, and enabling the cursor. The first
two operations are in dedicated functions update() and set_base().
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190927091301.10574-5-tzimmermann@suse.de
By putting cursor BOs at the high end of the video memory, we can avoid
memory fragmentation. Starting at the low end, contiguous video memory is
available for framebuffers.
The patch also simplifies the buffer swapping by splitting
struct ast_private.cursor_cache BO into two separate boffer objects. Cursor
images alternate between these buffers instead of offsets within cursor_cache.
v3:
* fixes space-before-tab error near AST_HWC_SIGNATURE_CHECKSUM
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190927090309.10254-6-tzimmermann@suse.de
