Use rcu_read_lock to read p->event_idr concurrently with other readers
and writers. Use p->event_mutex only for creating and destroying events
and in kfd_wait_on_events.
Protect the contents of the kfd_event structure with a per-event
spinlock that can be taken inside the rcu_read_lock critical section.
This eliminates contention of p->event_mutex in set_event, which tends
to be on the critical path for dispatch latency even when busy waiting
is used. It also eliminates lock contention in event interrupt handlers.
Since the p->event_mutex is now used much less, the impact of requiring
it in kfd_wait_on_events should also be much smaller.
This should improve event handling latency for processes using multiple
GPUs concurrently.
v2: Reschedule the worker periodically to avoid soft lockup warnings
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Sean Keely <Sean.Keely@amd.com> # v1
Tested-by: Sanjay Tripathi <sanjay.tripathi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
kfd_chardev() doesn't provide much useful information in dev_... messages
on multi-GPU systems because there is only one KFD device, which doesn't
correspond to any particular GPU. Use the actual GPU device to indicate
the GPU that caused a message.
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
When this was first implemented, overflows weren't expected in regular
operations, and tests weren't in place to cause said overflow. Now there
are cases where overflows occur with real workloads, but we know that
the kernel can handle this robustly, so move the message to a debug
message.
Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Update the SPDX License header for all the KFD files.
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Initializes kfd->device_info given either asic_type (enum) if GFX
version is less than GFX9, or GC IP version if greater. Also takes in vf
and the target compiler gfx version. Uses SDMA version to determine
num_sdma_queues_per_engine.
Convert device_info to a non-pointer member of kfd, change references
accordingly.
Change unsupported asic condition to only probe f2g, move device_info
initialization post-switch.
Signed-off-by: Graham Sider <Graham.Sider@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
alloc_workqueue is not checked for errors and as a result,
a potential NULL dereference could occur.
v2 (Felix Kuehling):
* Fix compile error (kfifo_free instead of fifo_free)
* Return proper error code
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Upon VM Fault, the VMID and PASID written by HW are zeros in
Hawaii. Instead of reading from ih_ring_entry, read directly
from the registers. This workaround fix the soft hang issues
caused by mishandled VM Fault in Hawaii.
Signed-off-by: Lan Xiao <Lan.Xiao@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
There's an ongoing effort to remove VLAs[1] from the kernel to eventually
turn on -Wvla. Switch to a constant value that covers all hardware.
[1] https://lkml.org/lkml/2018/3/7/621
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
In systems under heavy load the IH work may experience significant
scheduling delays.
Under load + system workqueue:
Max Latency: 7.023695 ms
Avg Latency: 0.263994 ms
Under load + high priority workqueue:
Max Latency: 1.162568 ms
Avg Latency: 0.163213 ms
Further work is required to measure the impact of per-cpu settings on IH
performance.
Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
We don't need to wait for all work to complete in the IH exit function.
We only need to make sure the interrupt_work has finished executing to
guarantee that ih_kfifo is no longer in use.
Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
A larger buffer will let us accommodate applications with a large amount
of semi-simultaneous event signals.
Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Replace our implementation of a lockless ring buffer with the standard
linux kernel kfifo.
We shouldn't maintain our own version of a standard data structure.
Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Using checkpatch.pl -f <file> showed a number of style issues. This
patch addresses as many of them as possible. Some long lines have been
left for readability, but attempts to minimize them have been made.
v2: Broke long lines in gfx_v7 get_fw_version
Signed-off-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
This patch adds the events module (kfd_events.c) and the interrupt
handle module for Kaveri (cik_event_interrupt.c).
The patch updates the interrupt_is_wanted(), so that it now calls the
interrupt isr function specific for the device that received the
interrupt. That function(implemented in cik_event_interrupt.c)
returns whether this interrupt is of interest to us or not.
The patch also updates the interrupt_wq(), so that it now calls the
device's specific wq function, which checks the interrupt source
and tries to signal relevant events.
v2:
Increase limit of signal events to 4096 per process
Remove bitfields from struct cik_ih_ring_entry
Rename radeon_kfd_event_mmap to kfd_event_mmap
Add debug prints to allocate_free_slot and allocate_signal_page
Make allocate_event_notification_slot return a correct value
Add warning prints to create_signal_event
Remove error print from IOCTL path
Reformatted debug prints in kfd_event_mmap
Map correct size (as received from mmap) in kfd_event_mmap
v3:
Reduce limit of signal events back to 256 per process
Fix allocation of kernel memory for signal events
Signed-off-by: Andrew Lewycky <Andrew.Lewycky@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
This patch adds the interrupt handling module, kfd_interrupt.c, and its
related members in different data structures to the amdkfd driver.
The amdkfd interrupt module maintains an internal interrupt ring
per amdkfd device. The internal interrupt ring contains interrupts
that needs further handling. The extra handling is deferred to
a later time through a workqueue.
There's no acknowledgment for the interrupts we use. The hardware
simply queues a new interrupt each time without waiting.
The fixed-size internal queue means that it's possible for us to lose
interrupts because we have no back-pressure to the hardware.
However, only interrupts that are "wanted" by amdkfd, are copied into
the amdkfd s/w interrupt ring, in order to minimize the chances
for overflow of the ring.
Signed-off-by: Andrew Lewycky <Andrew.Lewycky@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
The work queue couldn't reliably prevent the SW ring buffer from
overflowing, so dmesg was spammed by
kfd kfd: Interrupt ring overflow, dropping interrupt.
messages when running e.g. the Atlantis Substance demo from
https://wiki.unrealengine.com/Linux_Demos on Kaveri.
Since the SW ring buffer doesn't actually do anything at this point, just
remove it for now. When actual interrupt processing code is added to
amdkfd, it should try to do things immediately and only defer to work
queues when necessary.
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
This patch adds the interrupt handling module, in kfd_interrupt.c, and its
related members in different data structures to the amdkfd driver.
The amdkfd interrupt module maintains an internal interrupt ring per amdkfd
device. The internal interrupt ring contains interrupts that needs further
handling. The extra handling is deferred to a later time through a workqueue.
There's no acknowledgment for the interrupts we use. The hardware simply queues
a new interrupt each time without waiting.
The fixed-size internal queue means that it's possible for us to lose
interrupts because we have no back-pressure to the hardware.
v3:
Move amdkfd from drm/radeon/ to drm/amd/
Change device init
Made sure spin lock is taken only if init is complete
Moved bool field to the end of the structure
Signed-off-by: Andrew Lewycky <Andrew.Lewycky@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
