mirror of https://github.com/m-labs/artiq.git
116 lines
3.7 KiB
Python
116 lines
3.7 KiB
Python
"""Direct Memory Access (DMA) extension.
|
|
|
|
This feature allows storing pre-defined sequences of output RTIO events into
|
|
the core device's SDRAM, and playing them back at higher speeds than the CPU
|
|
alone could achieve.
|
|
"""
|
|
|
|
from artiq.language.core import syscall, kernel
|
|
from artiq.language.types import TInt32, TInt64, TStr, TNone, TTuple
|
|
from artiq.coredevice.exceptions import DMAError
|
|
|
|
from numpy import int64
|
|
|
|
|
|
@syscall
|
|
def dma_record_start(name: TStr) -> TNone:
|
|
raise NotImplementedError("syscall not simulated")
|
|
|
|
@syscall
|
|
def dma_record_stop(duration: TInt64) -> TNone:
|
|
raise NotImplementedError("syscall not simulated")
|
|
|
|
@syscall
|
|
def dma_erase(name: TStr) -> TNone:
|
|
raise NotImplementedError("syscall not simulated")
|
|
|
|
@syscall
|
|
def dma_retrieve(name: TStr) -> TTuple([TInt64, TInt32]):
|
|
raise NotImplementedError("syscall not simulated")
|
|
|
|
@syscall
|
|
def dma_playback(timestamp: TInt64, ptr: TInt32) -> TNone:
|
|
raise NotImplementedError("syscall not simulated")
|
|
|
|
|
|
class DMARecordContextManager:
|
|
"""Context manager returned by ``CoreDMA.record()``.
|
|
|
|
Upon entering, starts recording a DMA trace. All RTIO operations are
|
|
redirected to a newly created DMA buffer after this call, and ``now``
|
|
is reset to zero.
|
|
|
|
Upon leaving, stops recording a DMA trace. All recorded RTIO operations
|
|
are stored in a newly created trace, and ``now`` is restored to the value
|
|
it had before the context manager was entered.
|
|
"""
|
|
def __init__(self):
|
|
self.name = ""
|
|
self.saved_now_mu = int64(0)
|
|
|
|
@kernel
|
|
def __enter__(self):
|
|
dma_record_start(self.name) # this may raise, so do it before altering now
|
|
self.saved_now_mu = now_mu()
|
|
at_mu(0)
|
|
|
|
@kernel
|
|
def __exit__(self, type, value, traceback):
|
|
dma_record_stop(now_mu()) # see above
|
|
at_mu(self.saved_now_mu)
|
|
|
|
|
|
class CoreDMA:
|
|
"""Core device Direct Memory Access (DMA) driver.
|
|
|
|
Gives access to the DMA functionality of the core device.
|
|
"""
|
|
|
|
kernel_invariants = {"core", "recorder"}
|
|
|
|
def __init__(self, dmgr, core_device="core"):
|
|
self.core = dmgr.get(core_device)
|
|
self.recorder = DMARecordContextManager()
|
|
self.epoch = 0
|
|
|
|
@kernel
|
|
def record(self, name):
|
|
"""Returns a context manager that will record a DMA trace called ``name``.
|
|
Any previously recorded trace with the same name is overwritten.
|
|
The trace will persist across kernel switches."""
|
|
self.epoch += 1
|
|
self.recorder.name = name
|
|
return self.recorder
|
|
|
|
@kernel
|
|
def erase(self, name):
|
|
"""Removes the DMA trace with the given name from storage."""
|
|
self.epoch += 1
|
|
dma_erase(name)
|
|
|
|
@kernel
|
|
def playback(self, name):
|
|
"""Replays a previously recorded DMA trace. This function blocks until
|
|
the entire trace is submitted to the RTIO FIFOs."""
|
|
(advance_mu, ptr) = dma_retrieve(name)
|
|
dma_playback(now_mu(), ptr)
|
|
delay_mu(advance_mu)
|
|
|
|
@kernel
|
|
def get_handle(self, name):
|
|
"""Returns a handle to a previously recorded DMA trace. The returned handle
|
|
is only valid until the next call to :meth:`record` or :meth:`erase`."""
|
|
(advance_mu, ptr) = dma_retrieve(name)
|
|
return (self.epoch, advance_mu, ptr)
|
|
|
|
@kernel
|
|
def playback_handle(self, handle):
|
|
"""Replays a handle obtained with :meth:`get_handle`. Using this function
|
|
is much faster than :meth:`playback` for replaying a set of traces repeatedly,
|
|
but incurs the overhead of managing the handles onto the programmer."""
|
|
(epoch, advance_mu, ptr) = handle
|
|
if self.epoch != epoch:
|
|
raise DMAError("Invalid handle")
|
|
dma_playback(now_mu(), ptr)
|
|
delay_mu(advance_mu)
|