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/include/lib/el3_runtime/cpu_data.h b/include/lib/el3_runtime/cpu_data.h
index 910b153..3b00a5e 100644
--- a/include/lib/el3_runtime/cpu_data.h
+++ b/include/lib/el3_runtime/cpu_data.h
@@ -50,10 +50,20 @@
#if CRASH_REPORTING
#define CPU_DATA_LOG2SIZE 7
+#define CPU_DATA_CRASH_BUF_END (CPU_DATA_CRASH_BUF_OFFSET + \
+ CPU_DATA_CRASH_BUF_SIZE)
#else
#define CPU_DATA_LOG2SIZE 6
+#define CPU_DATA_CRASH_BUF_END CPU_DATA_CRASH_BUF_OFFSET
#endif
+#if ENABLE_RUNTIME_INSTRUMENTATION
+/* Temporary space to store PMF timestamps from assembly code */
+#define CPU_DATA_PMF_TS_COUNT 1
+#define CPU_DATA_PMF_TS0_OFFSET CPU_DATA_CRASH_BUF_END
+#define CPU_DATA_PMF_TS0_IDX 0
+#endif
+
#ifndef __ASSEMBLY__
#include <arch_helpers.h>
@@ -96,6 +106,9 @@
#if CRASH_REPORTING
u_register_t crash_buf[CPU_DATA_CRASH_BUF_SIZE >> 3];
#endif
+#if ENABLE_RUNTIME_INSTRUMENTATION
+ uint64_t cpu_data_pmf_ts[CPU_DATA_PMF_TS_COUNT];
+#endif
struct psci_cpu_data psci_svc_cpu_data;
#if PLAT_PCPU_DATA_SIZE
uint8_t platform_cpu_data[PLAT_PCPU_DATA_SIZE];
@@ -116,6 +129,12 @@
(cpu_data_t, cpu_ops_ptr),
assert_cpu_data_cpu_ops_ptr_offset_mismatch);
+#if ENABLE_RUNTIME_INSTRUMENTATION
+CASSERT(CPU_DATA_PMF_TS0_OFFSET == __builtin_offsetof
+ (cpu_data_t, cpu_data_pmf_ts[0]),
+ assert_cpu_data_pmf_ts0_offset_mismatch);
+#endif
+
struct cpu_data *_cpu_data_by_index(uint32_t cpu_index);
#ifndef AARCH32