Add PMF instrumentation points in TF
In order to quantify the overall time spent in the PSCI software
implementation, an initial collection of PMF instrumentation points
has been added.
Instrumentation has been added to the following code paths:
- Entry to PSCI SMC handler. The timestamp is captured as early
as possible during the runtime exception and stored in memory
before entering the PSCI SMC handler.
- Exit from PSCI SMC handler. The timestamp is captured after
normal return from the PSCI SMC handler or if a low power state
was requested it is captured in the bl31 warm boot path before
return to normal world.
- Entry to low power state. The timestamp is captured before entry
to a low power state which implies either standby or power down.
As these power states are mutually exclusive, only one timestamp
is defined to describe both. It is possible to differentiate between
the two power states using the PSCI STAT interface.
- Exit from low power state. The timestamp is captured after a standby
or power up operation has completed.
To calculate the number of cycles spent running code in Trusted Firmware
one can perform the following calculation:
(exit_psci - enter_psci) - (exit_low_pwr - enter_low_pwr).
The resulting number of cycles can be converted to time given the
frequency of the counter.
Change-Id: Ie3b8f3d16409b6703747093b3a2d5c7429ad0166
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
diff --git a/Makefile b/Makefile
index 2b630b3..3521117 100644
--- a/Makefile
+++ b/Makefile
@@ -117,6 +117,12 @@
SEPARATE_CODE_AND_RODATA := 0
# Flag to enable new version of image loading
LOAD_IMAGE_V2 := 0
+# Flag to enable runtime instrumentation using PMF
+ENABLE_RUNTIME_INSTRUMENTATION := 0
+
+ifeq (${ENABLE_RUNTIME_INSTRUMENTATION}, 1)
+ENABLE_PMF := 1
+endif
################################################################################
# Checkpatch script options
@@ -466,6 +472,7 @@
$(eval $(call assert_boolean,ENABLE_PSCI_STAT))
$(eval $(call assert_boolean,SEPARATE_CODE_AND_RODATA))
$(eval $(call assert_boolean,LOAD_IMAGE_V2))
+$(eval $(call assert_boolean,ENABLE_RUNTIME_INSTRUMENTATION))
################################################################################
@@ -497,6 +504,7 @@
$(eval $(call add_define,ENABLE_PSCI_STAT))
$(eval $(call add_define,SEPARATE_CODE_AND_RODATA))
$(eval $(call add_define,LOAD_IMAGE_V2))
+$(eval $(call add_define,ENABLE_RUNTIME_INSTRUMENTATION))
# Define the EL3_PAYLOAD_BASE flag only if it is provided.
ifdef EL3_PAYLOAD_BASE
$(eval $(call add_define,EL3_PAYLOAD_BASE))