arm-trusted-firmware/bl31/aarch64/bl31_entrypoint.S
dp-arm 872be88a29 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>
2016-10-12 15:36:49 +01:00

224 lines
7.9 KiB
ArmAsm

/*
* Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#include <bl_common.h>
#include <el3_common_macros.S>
#include <pmf_asm_macros.S>
#include <runtime_instr.h>
#include <xlat_tables.h>
.globl bl31_entrypoint
.globl bl31_warm_entrypoint
/* -----------------------------------------------------
* bl31_entrypoint() is the cold boot entrypoint,
* executed only by the primary cpu.
* -----------------------------------------------------
*/
func bl31_entrypoint
#if !RESET_TO_BL31
/* ---------------------------------------------------------------
* Preceding bootloader has populated x0 with a pointer to a
* 'bl31_params' structure & x1 with a pointer to platform
* specific structure
* ---------------------------------------------------------------
*/
mov x20, x0
mov x21, x1
/* ---------------------------------------------------------------------
* For !RESET_TO_BL31 systems, only the primary CPU ever reaches
* bl31_entrypoint() during the cold boot flow, so the cold/warm boot
* and primary/secondary CPU logic should not be executed in this case.
*
* Also, assume that the previous bootloader has already set up the CPU
* endianness and has initialised the memory.
* ---------------------------------------------------------------------
*/
el3_entrypoint_common \
_set_endian=0 \
_warm_boot_mailbox=0 \
_secondary_cold_boot=0 \
_init_memory=0 \
_init_c_runtime=1 \
_exception_vectors=runtime_exceptions
/* ---------------------------------------------------------------------
* Relay the previous bootloader's arguments to the platform layer
* ---------------------------------------------------------------------
*/
mov x0, x20
mov x1, x21
#else
/* ---------------------------------------------------------------------
* For RESET_TO_BL31 systems which have a programmable reset address,
* bl31_entrypoint() is executed only on the cold boot path so we can
* skip the warm boot mailbox mechanism.
* ---------------------------------------------------------------------
*/
el3_entrypoint_common \
_set_endian=1 \
_warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS \
_secondary_cold_boot=!COLD_BOOT_SINGLE_CPU \
_init_memory=1 \
_init_c_runtime=1 \
_exception_vectors=runtime_exceptions
/* ---------------------------------------------------------------------
* For RESET_TO_BL31 systems, BL31 is the first bootloader to run so
* there's no argument to relay from a previous bootloader. Zero the
* arguments passed to the platform layer to reflect that.
* ---------------------------------------------------------------------
*/
mov x0, 0
mov x1, 0
#endif /* RESET_TO_BL31 */
/* ---------------------------------------------
* Perform platform specific early arch. setup
* ---------------------------------------------
*/
bl bl31_early_platform_setup
bl bl31_plat_arch_setup
/* ---------------------------------------------
* Jump to main function.
* ---------------------------------------------
*/
bl bl31_main
/* -------------------------------------------------------------
* Clean the .data & .bss sections to main memory. This ensures
* that any global data which was initialised by the primary CPU
* is visible to secondary CPUs before they enable their data
* caches and participate in coherency.
* -------------------------------------------------------------
*/
adr x0, __DATA_START__
adr x1, __DATA_END__
sub x1, x1, x0
bl clean_dcache_range
adr x0, __BSS_START__
adr x1, __BSS_END__
sub x1, x1, x0
bl clean_dcache_range
b el3_exit
endfunc bl31_entrypoint
/* --------------------------------------------------------------------
* This CPU has been physically powered up. It is either resuming from
* suspend or has simply been turned on. In both cases, call the BL31
* warmboot entrypoint
* --------------------------------------------------------------------
*/
func bl31_warm_entrypoint
#if ENABLE_RUNTIME_INSTRUMENTATION
/*
* This timestamp update happens with cache off. The next
* timestamp collection will need to do cache maintenance prior
* to timestamp update.
*/
pmf_calc_timestamp_addr rt_instr_svc RT_INSTR_EXIT_HW_LOW_PWR
mrs x1, cntpct_el0
str x1, [x0]
#endif
/*
* On the warm boot path, most of the EL3 initialisations performed by
* 'el3_entrypoint_common' must be skipped:
*
* - Only when the platform bypasses the BL1/BL31 entrypoint by
* programming the reset address do we need to set the CPU endianness.
* In other cases, we assume this has been taken care by the
* entrypoint code.
*
* - No need to determine the type of boot, we know it is a warm boot.
*
* - Do not try to distinguish between primary and secondary CPUs, this
* notion only exists for a cold boot.
*
* - No need to initialise the memory or the C runtime environment,
* it has been done once and for all on the cold boot path.
*/
el3_entrypoint_common \
_set_endian=PROGRAMMABLE_RESET_ADDRESS \
_warm_boot_mailbox=0 \
_secondary_cold_boot=0 \
_init_memory=0 \
_init_c_runtime=0 \
_exception_vectors=runtime_exceptions
/* --------------------------------------------
* Enable the MMU with the DCache disabled. It
* is safe to use stacks allocated in normal
* memory as a result. All memory accesses are
* marked nGnRnE when the MMU is disabled. So
* all the stack writes will make it to memory.
* All memory accesses are marked Non-cacheable
* when the MMU is enabled but D$ is disabled.
* So used stack memory is guaranteed to be
* visible immediately after the MMU is enabled
* Enabling the DCache at the same time as the
* MMU can lead to speculatively fetched and
* possibly stale stack memory being read from
* other caches. This can lead to coherency
* issues.
* --------------------------------------------
*/
mov x0, #DISABLE_DCACHE
bl bl31_plat_enable_mmu
bl psci_warmboot_entrypoint
#if ENABLE_RUNTIME_INSTRUMENTATION
pmf_calc_timestamp_addr rt_instr_svc RT_INSTR_EXIT_PSCI
mov x19, x0
/*
* Invalidate before updating timestamp to ensure previous timestamp
* updates on the same cache line with caches disabled are properly
* seen by the same core. Without the cache invalidate, the core might
* write into a stale cache line.
*/
mov x1, #PMF_TS_SIZE
mov x20, x30
bl inv_dcache_range
mov x30, x20
mrs x0, cntpct_el0
str x0, [x19]
#endif
b el3_exit
endfunc bl31_warm_entrypoint