arm-trusted-firmware/bl31/aarch64/bl31_entrypoint.S

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2013-10-25 09:08:21 +01:00
/*
Introduce PSCI Library Interface This patch introduces the PSCI Library interface. The major changes introduced are as follows: * Earlier BL31 was responsible for Architectural initialization during cold boot via bl31_arch_setup() whereas PSCI was responsible for the same during warm boot. This functionality is now consolidated by the PSCI library and it does Architectural initialization via psci_arch_setup() during both cold and warm boots. * Earlier the warm boot entry point was always `psci_entrypoint()`. This was not flexible enough as a library interface. Now PSCI expects the runtime firmware to provide the entry point via `psci_setup()`. A new function `bl31_warm_entrypoint` is introduced in BL31 and the previous `psci_entrypoint()` is deprecated. * The `smc_helpers.h` is reorganized to separate the SMC Calling Convention defines from the Trusted Firmware SMC helpers. The former is now in a new header file `smcc.h` and the SMC helpers are moved to Architecture specific header. * The CPU context is used by PSCI for context initialization and restoration after power down (PSCI Context). It is also used by BL31 for SMC handling and context management during Normal-Secure world switch (SMC Context). The `psci_smc_handler()` interface is redefined to not use SMC helper macros thus enabling to decouple the PSCI context from EL3 runtime firmware SMC context. This enables PSCI to be integrated with other runtime firmware using a different SMC context. NOTE: With this patch the architectural setup done in `bl31_arch_setup()` is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be invoked prior to architectural setup. It is highly unlikely that the platform setup will depend on architectural setup and cause any failure. Please be be aware of this change in sequence. Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
2016-04-29 19:01:30 +01:00
* Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
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*
* 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>
Introduce PSCI Library Interface This patch introduces the PSCI Library interface. The major changes introduced are as follows: * Earlier BL31 was responsible for Architectural initialization during cold boot via bl31_arch_setup() whereas PSCI was responsible for the same during warm boot. This functionality is now consolidated by the PSCI library and it does Architectural initialization via psci_arch_setup() during both cold and warm boots. * Earlier the warm boot entry point was always `psci_entrypoint()`. This was not flexible enough as a library interface. Now PSCI expects the runtime firmware to provide the entry point via `psci_setup()`. A new function `bl31_warm_entrypoint` is introduced in BL31 and the previous `psci_entrypoint()` is deprecated. * The `smc_helpers.h` is reorganized to separate the SMC Calling Convention defines from the Trusted Firmware SMC helpers. The former is now in a new header file `smcc.h` and the SMC helpers are moved to Architecture specific header. * The CPU context is used by PSCI for context initialization and restoration after power down (PSCI Context). It is also used by BL31 for SMC handling and context management during Normal-Secure world switch (SMC Context). The `psci_smc_handler()` interface is redefined to not use SMC helper macros thus enabling to decouple the PSCI context from EL3 runtime firmware SMC context. This enables PSCI to be integrated with other runtime firmware using a different SMC context. NOTE: With this patch the architectural setup done in `bl31_arch_setup()` is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be invoked prior to architectural setup. It is highly unlikely that the platform setup will depend on architectural setup and cause any failure. Please be be aware of this change in sequence. Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
2016-04-29 19:01:30 +01:00
#include <xlat_tables.h>
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.globl bl31_entrypoint
Introduce PSCI Library Interface This patch introduces the PSCI Library interface. The major changes introduced are as follows: * Earlier BL31 was responsible for Architectural initialization during cold boot via bl31_arch_setup() whereas PSCI was responsible for the same during warm boot. This functionality is now consolidated by the PSCI library and it does Architectural initialization via psci_arch_setup() during both cold and warm boots. * Earlier the warm boot entry point was always `psci_entrypoint()`. This was not flexible enough as a library interface. Now PSCI expects the runtime firmware to provide the entry point via `psci_setup()`. A new function `bl31_warm_entrypoint` is introduced in BL31 and the previous `psci_entrypoint()` is deprecated. * The `smc_helpers.h` is reorganized to separate the SMC Calling Convention defines from the Trusted Firmware SMC helpers. The former is now in a new header file `smcc.h` and the SMC helpers are moved to Architecture specific header. * The CPU context is used by PSCI for context initialization and restoration after power down (PSCI Context). It is also used by BL31 for SMC handling and context management during Normal-Secure world switch (SMC Context). The `psci_smc_handler()` interface is redefined to not use SMC helper macros thus enabling to decouple the PSCI context from EL3 runtime firmware SMC context. This enables PSCI to be integrated with other runtime firmware using a different SMC context. NOTE: With this patch the architectural setup done in `bl31_arch_setup()` is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be invoked prior to architectural setup. It is highly unlikely that the platform setup will depend on architectural setup and cause any failure. Please be be aware of this change in sequence. Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
2016-04-29 19:01:30 +01:00
.globl bl31_warm_entrypoint
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/* -----------------------------------------------------
* 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.
* ---------------------------------------------------------------------
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*/
mov x0, 0
mov x1, 0
#endif /* RESET_TO_BL31 */
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/* ---------------------------------------------
* Perform platform specific early arch. setup
* ---------------------------------------------
*/
bl bl31_early_platform_setup
bl bl31_plat_arch_setup
/* ---------------------------------------------
* Jump to main function.
* ---------------------------------------------
*/
bl bl31_main
Make generic code work in presence of system caches On the ARMv8 architecture, cache maintenance operations by set/way on the last level of integrated cache do not affect the system cache. This means that such a flush or clean operation could result in the data being pushed out to the system cache rather than main memory. Another CPU could access this data before it enables its data cache or MMU. Such accesses could be serviced from the main memory instead of the system cache. If the data in the sysem cache has not yet been flushed or evicted to main memory then there could be a loss of coherency. The only mechanism to guarantee that the main memory will be updated is to use cache maintenance operations to the PoC by MVA(See section D3.4.11 (System level caches) of ARMv8-A Reference Manual (Issue A.g/ARM DDI0487A.G). This patch removes the reliance of Trusted Firmware on the flush by set/way operation to ensure visibility of data in the main memory. Cache maintenance operations by MVA are now used instead. The following are the broad category of changes: 1. The RW areas of BL2/BL31/BL32 are invalidated by MVA before the C runtime is initialised. This ensures that any stale cache lines at any level of cache are removed. 2. Updates to global data in runtime firmware (BL31) by the primary CPU are made visible to secondary CPUs using a cache clean operation by MVA. 3. Cache maintenance by set/way operations are only used prior to power down. NOTE: NON-UPSTREAM TRUSTED FIRMWARE CODE SHOULD MAKE EQUIVALENT CHANGES IN ORDER TO FUNCTION CORRECTLY ON PLATFORMS WITH SUPPORT FOR SYSTEM CACHES. Fixes ARM-software/tf-issues#205 Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a
2015-09-11 16:03:13 +01:00
/* -------------------------------------------------------------
* 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
Introduce PSCI Library Interface This patch introduces the PSCI Library interface. The major changes introduced are as follows: * Earlier BL31 was responsible for Architectural initialization during cold boot via bl31_arch_setup() whereas PSCI was responsible for the same during warm boot. This functionality is now consolidated by the PSCI library and it does Architectural initialization via psci_arch_setup() during both cold and warm boots. * Earlier the warm boot entry point was always `psci_entrypoint()`. This was not flexible enough as a library interface. Now PSCI expects the runtime firmware to provide the entry point via `psci_setup()`. A new function `bl31_warm_entrypoint` is introduced in BL31 and the previous `psci_entrypoint()` is deprecated. * The `smc_helpers.h` is reorganized to separate the SMC Calling Convention defines from the Trusted Firmware SMC helpers. The former is now in a new header file `smcc.h` and the SMC helpers are moved to Architecture specific header. * The CPU context is used by PSCI for context initialization and restoration after power down (PSCI Context). It is also used by BL31 for SMC handling and context management during Normal-Secure world switch (SMC Context). The `psci_smc_handler()` interface is redefined to not use SMC helper macros thus enabling to decouple the PSCI context from EL3 runtime firmware SMC context. This enables PSCI to be integrated with other runtime firmware using a different SMC context. NOTE: With this patch the architectural setup done in `bl31_arch_setup()` is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be invoked prior to architectural setup. It is highly unlikely that the platform setup will depend on architectural setup and cause any failure. Please be be aware of this change in sequence. Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
2016-04-29 19:01:30 +01:00
/* --------------------------------------------------------------------
* 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
/*
* 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
b el3_exit
endfunc bl31_warm_entrypoint