commit 1878dab5f2fb860ae98e5e1dafcdb5cec7d33349
author erik.andersson@arm.com <erik.andersson@arm.com> Tue Mar 16 09:40:24 2021 +0100
committer erik.andersson@arm.com <erik.andersson@arm.com> Fri Mar 19 14:05:17 2021 +0100
tree 55e1c5c076453bf8df8572bc10c073d94782b5b9
parent a8e48e6792216974d41c7fc69d9406916c153fba

MLBEDSW-3458: Added command stream size check.

If the command stream size exceeds a certain threshold,
a VelaError will now be raised.

Signed-off-by: erik.andersson@arm.com <erik.andersson@arm.com>
Change-Id: I9b9383f4c298a778b160cd527374e9244e4cae26

ethosu/vela/driver_actions.py

diff --git a/ethosu/vela/driver_actions.py b/ethosu/vela/driver_actions.py
index 5a85df0..317b2a6 100644
--- a/ethosu/vela/driver_actions.py
+++ b/ethosu/vela/driver_actions.py
@@ -24,6 +24,7 @@
 from .architecture_features import Accelerator
 from .architecture_features import ArchitectureFeatures
 from .architecture_features import create_default_arch
+from .errors import VelaError
 from .ethos_u55_regs.ethos_u55_regs import ARCH_VER
 from .ethos_u55_regs.ethos_u55_regs import config_r
 from .ethos_u55_regs.ethos_u55_regs import id_r
@@ -120,6 +121,12 @@
     da_list: List[int] = []
     emit_fourcc(da_list, "COP1")
     emit_config(da_list, 0, 1, arch)
+    if len(register_command_stream) >= 1 << 24:
+        raise VelaError(
+            "The command stream exceeds the driver size limit of 64 MiB. "
+            f"The current stream size is {4*len(register_command_stream)/2**20:.2F} MiB"
+        )
+
     emit_cmd_stream_header(da_list, len(register_command_stream))
 
     # Append command stream words

ethosu/vela/npu_serialisation.py

diff --git a/ethosu/vela/npu_serialisation.py b/ethosu/vela/npu_serialisation.py
index 6623053..27c46ea 100644
--- a/ethosu/vela/npu_serialisation.py
+++ b/ethosu/vela/npu_serialisation.py
@@ -119,7 +119,6 @@
                     ps.ifm2_tensor.mem_type not in (MemType.Scratch, MemType.Scratch_fast)
                 ):
                     copy_ifm_values_to_memory_tensor(sg.flash_tensor, ps.ifm2_tensor)
-
     sg.command_stream_tensor = make_memory_tensor(
         sg.name + "_command_stream", flash_area, MemType.Permanent_CPU, command_stream_size_bytes, True, arch
     )

ethosu/vela/register_command_stream_generator.py

diff --git a/ethosu/vela/register_command_stream_generator.py b/ethosu/vela/register_command_stream_generator.py
index ad29dae..f925369 100644
--- a/ethosu/vela/register_command_stream_generator.py
+++ b/ethosu/vela/register_command_stream_generator.py
@@ -58,6 +58,7 @@
 from .architecture_features import create_default_arch
 from .architecture_features import SharedBufferArea
 from .architecture_features import SHRAMElements
+from .errors import VelaError
 from .ethos_u55_regs.ethos_u55_regs import acc_format
 from .ethos_u55_regs.ethos_u55_regs import activation
 from .ethos_u55_regs.ethos_u55_regs import cmd0
@@ -944,6 +945,13 @@
     # Fill in final part of command stream:
     emit.cmd_do_operation(cmd0.NPU_OP_STOP, param=0xFFFF)
     res = emit.to_list()
+
+    if emit.size_in_bytes() >= 1 << 24:
+        raise VelaError(
+            f"The command stream size exceeds the hardware limit of 16 MiB. "
+            f"The current stream size is {emit.size_in_bytes()/2**20:.2F} MiB."
+        )
+
     if verbose:
         emit.print_cmds()
         print("number of commands", len(emit.cmd_stream))