When a platform port does not define PLAT_PERCPU_BAKERY_LOCK_SIZE, the total
memory that should be allocated per-cpu to accommodate all bakery locks is
calculated by the linker in bl31.ld.S. The linker stores this value in the
__PERCPU_BAKERY_LOCK_SIZE__ linker symbol. The runtime value of this symbol is
different from the link time value as the symbol is relocated into the current
section (.bss). This patch fixes this issue by marking the symbol as ABSOLUTE
which allows it to retain its correct value even at runtime.
The description of PLAT_PERCPU_BAKERY_LOCK_SIZE in the porting-guide.md has been
made clearer as well.
Change-Id: Ia0cfd42f51deaf739d792297e60cad5c6e6e610b
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.
FixesARM-software/tf-issues#205
Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a
This patch unifies the bakery lock api's across coherent and normal
memory implementation of locks by using same data type `bakery_lock_t`
and similar arguments to functions.
A separate section `bakery_lock` has been created and used to allocate
memory for bakery locks using `DEFINE_BAKERY_LOCK`. When locks are
allocated in normal memory, each lock for a core has to spread
across multiple cache lines. By using the total size allocated in a
separate cache line for a single core at compile time, the memory for
other core locks is allocated at link time by multiplying the single
core locks size with (PLATFORM_CORE_COUNT - 1). The normal memory lock
algorithm now uses lock address instead of the `id` in the per_cpu_data.
For locks allocated in coherent memory, it moves locks from
tzfw_coherent_memory to bakery_lock section.
The bakery locks are allocated as part of bss or in coherent memory
depending on usage of coherent memory. Both these regions are
initialised to zero as part of run_time_init before locks are used.
Hence, bakery_lock_init() is made an empty function as the lock memory
is already initialised to zero.
The above design lead to the removal of psci bakery locks from
non_cpu_power_pd_node to psci_locks.
NOTE: THE BAKERY LOCK API WHEN USE_COHERENT_MEM IS NOT SET HAS CHANGED.
THIS IS A BREAKING CHANGE FOR ALL PLATFORM PORTS THAT ALLOCATE BAKERY
LOCKS IN NORMAL MEMORY.
Change-Id: Ic3751c0066b8032dcbf9d88f1d4dc73d15f61d8b
This patch migrates the rest of Trusted Firmware excluding Secure Payload and
the dispatchers to the new platform and context management API. The per-cpu
data framework APIs which took MPIDRs as their arguments are deleted and only
the ones which take core index as parameter are retained.
Change-Id: I839d05ad995df34d2163a1cfed6baa768a5a595d
This commit does the switch to the new PSCI framework implementation replacing
the existing files in PSCI folder with the ones in PSCI1.0 folder. The
corresponding makefiles are modified as required for the new implementation.
The platform.h header file is also is switched to the new one
as required by the new frameworks. The build flag ENABLE_PLAT_COMPAT defaults
to 1 to enable compatibility layer which let the existing platform ports to
continue to build and run with minimal changes.
The default weak implementation of platform_get_core_pos() is now removed from
platform_helpers.S and is provided by the compatibility layer.
Note: The Secure Payloads and their dispatchers still use the old platform
and framework APIs and hence it is expected that the ENABLE_PLAT_COMPAT build
flag will remain enabled in subsequent patch. The compatibility for SPDs using
the older APIs on platforms migrated to the new APIs will be added in the
following patch.
Change-Id: I18c51b3a085b564aa05fdd98d11c9f3335712719
This patch introduces new platform APIs and context management helper APIs
to support the new topology framework based on linear core position. This
framework will be introduced in the follwoing patch and it removes the
assumption that the MPIDR based affinity levels map directly to levels
in a power domain tree. The new platforms APIs and context management
helpers based on core position are as described below:
* plat_my_core_pos() and plat_core_pos_by_mpidr()
These 2 new mandatory platform APIs are meant to replace the existing
'platform_get_core_pos()' API. The 'plat_my_core_pos()' API returns the
linear index of the calling core and 'plat_core_pos_by_mpidr()' returns
the linear index of a core specified by its MPIDR. The latter API will also
validate the MPIDR passed as an argument and will return an error code (-1)
if an invalid MPIDR is passed as the argument. This enables the caller to
safely convert an MPIDR of another core to its linear index without querying
the PSCI topology tree e.g. during a call to PSCI CPU_ON.
Since the 'plat_core_pos_by_mpidr()' API verifies an MPIDR, which is always
platform specific, it is no longer possible to maintain a default implementation
of this API. Also it might not be possible for a platform port to verify an
MPIDR before the C runtime has been setup or the topology has been initialized.
This would prevent 'plat_core_pos_by_mpidr()' from being callable prior to
topology setup. As a result, the generic Trusted Firmware code does not call
this API before the topology setup has been done.
The 'plat_my_core_pos' API should be able to run without a C runtime.
Since this API needs to return a core position which is equal to the one
returned by 'plat_core_pos_by_mpidr()' API for the corresponding MPIDR,
this too cannot have default implementation and is a mandatory API for
platform ports. These APIs will be implemented by the ARM reference platform
ports later in the patch stack.
* plat_get_my_stack() and plat_set_my_stack()
These APIs are the stack management APIs which set/return stack addresses
appropriate for the calling core. These replace the 'platform_get_stack()' and
'platform_set_stack()' APIs. A default weak MP version and a global UP version
of these APIs are provided for the platforms.
* Context management helpers based on linear core position
A set of new context management(CM) helpers viz cm_get_context_by_index(),
cm_set_context_by_index(), cm_init_my_context() and cm_init_context_by_index()
are defined which are meant to replace the old helpers which took MPIDR
as argument. The old CM helpers are implemented based on the new helpers to
allow for code consolidation and will be deprecated once the switch to the new
framework is done.
Change-Id: I89758632b370c2812973a4b2efdd9b81a41f9b69
This patch introduces a new platform build option, called
PROGRAMMABLE_RESET_ADDRESS, which tells whether the platform has
a programmable or fixed reset vector address.
If the reset vector address is fixed then the code relies on the
platform_get_entrypoint() mailbox mechanism to figure out where
it is supposed to jump. On the other hand, if it is programmable
then it is assumed that the platform code will program directly
the right address into the RVBAR register (instead of using the
mailbox redirection) so the mailbox is ignored in this case.
Change-Id: If59c3b11fb1f692976e1d8b96c7e2da0ebfba308
The attempt to run the CPU reset code as soon as possible after reset
results in highly complex conditional code relating to the
RESET_TO_BL31 option.
This patch relaxes this requirement a little. In the BL1, BL3-1 and
PSCI entrypoints code, the sequence of operations is now as follows:
1) Detect whether it is a cold or warm boot;
2) For cold boot, detect whether it is the primary or a secondary
CPU. This is needed to handle multiple CPUs entering cold reset
simultaneously;
3) Run the CPU init code.
This patch also abstracts the EL3 registers initialisation done by
the BL1, BL3-1 and PSCI entrypoints into common code.
This improves code re-use and consolidates the code flows for
different types of systems.
NOTE: THE FUNCTION plat_secondary_cold_boot() IS NOW EXPECTED TO
NEVER RETURN. THIS PATCH FORCES PLATFORM PORTS THAT RELIED ON THE
FORMER RETRY LOOP AT THE CALL SITE TO MODIFY THEIR IMPLEMENTATION.
OTHERWISE, SECONDARY CPUS WILL PANIC.
Change-Id: If5ecd74d75bee700b1bd718d23d7556b8f863546
There are couple of issues with how the interrupt routing framework in BL3_1
handles spurious interrupts.
1. In the macro 'handle_interrupt_exception', if a spurious interrupt is
detected by plat_ic_get_pending_interrupt_type(), then execution jumps to
'interrupt_exit_\label'. This macro uses the el3_exit() function to return to
the original exception level. el3_exit() attempts to restore the SPSR_EL3 and
ELR_EL3 registers with values from the current CPU context. Since these
registers were not saved in this code path, it programs stale values into
these registers. This leads to unpredictable behaviour after the execution of
the ERET instruction.
2. When an interrupt is routed to EL3, it could be de-asserted before the
GICC_HPPIR is read in plat_ic_get_pending_interrupt_type(). There could be
another interrupt pending at the same time e.g. a non-secure interrupt. Its
type will be returned instead of the original interrupt. This would result in
a call to get_interrupt_type_handler(). The firmware will panic if the
handler for this type of interrupt has not been registered.
This patch fixes the first problem by saving SPSR_EL3 and ELR_EL3 early in the
'handle_interrupt_exception' macro, instead of only doing so once the validity
of the interrupt has been determined.
The second problem is fixed by returning execution back to the lower exception
level through the 'interrupt_exit_\label' label instead of treating it as an
error condition. The 'interrupt_error_\label' label has been removed since it is
no longer used.
FixesARM-software/tf-issues#305
Change-Id: I81c729a206d461084db501bb81b44dff435021e8
In order for the symbol table in the ELF file to contain the size of
functions written in assembly, it is necessary to report it to the
assembler using the .size directive.
To fulfil the above requirements, this patch introduces an 'endfunc'
macro which contains the .endfunc and .size directives. It also adds
a .func directive to the 'func' assembler macro.
The .func/.endfunc have been used so the assembler can fail if
endfunc is omitted.
FixesARM-Software/tf-issues#295
Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>
The cpu-ops pointer was initialized before enabling the data cache in the cold
and warm boot paths. This required a DCIVAC cache maintenance operation to
invalidate any stale cache lines resident in other cpus.
This patch moves this initialization to the bl31_arch_setup() function
which is always called after the data cache and MMU has been enabled.
This change removes the need:
1. for the DCIVAC cache maintenance operation.
2. to initialise the CPU ops upon resumption from a PSCI CPU_SUSPEND
call since memory contents are always preserved in this case.
Change-Id: Ibb2fa2f7460d1a1f1e721242025e382734c204c6
This patch modifies the declarations of the functions printf() et al.
and adds the right GCC attribute to request the compiler to check
the type of the arguments passed to these functions against the given
format string. This will ensure that the compiler outputs warning
messages like the following whenever it detects an inconsistency:
file.c:42: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long int’
It also fixes the type mismatch inconsistencies that it revealed
across the code base.
NOTE: THIS PATCH MAY FORCE PLATFORM PORTS OR SP/SPDS THAT USE THE
PRINTF FAMILY OF FUNCTIONS TO FIX ANY TYPE MISMATCH INCONSISTENCIES.
Change-Id: If36bb54ec7d6dd2cb4791d89b02a24ac13fd2df6
This patch adds support to call the reset_handler() function in BL3-1 in the
cold and warm boot paths when another Boot ROM reset_handler() has already run.
This means the BL1 and BL3-1 versions of the CPU and platform specific reset
handlers may execute different code to each other. This enables a developer to
perform additional actions or undo actions already performed during the first
call of the reset handlers e.g. apply additional errata workarounds.
Typically, the reset handler will be first called from the BL1 Boot ROM. Any
additional functionality can be added to the reset handler when it is called
from BL3-1 resident in RW memory. The constant FIRST_RESET_HANDLER_CALL is used
to identify whether this is the first version of the reset handler code to be
executed or an overridden version of the code.
The Cortex-A57 errata workarounds are applied only if they have not already been
applied.
FixesARM-software/tf-issue#275
Change-Id: Id295f106e4fda23d6736debdade2ac7f2a9a9053
This patch provides an option to specify a interrupt routing model
where non-secure interrupts (IRQs) are routed to EL3 instead of S-EL1.
When such an interrupt occurs, the TSPD arranges a return to
the normal world after saving any necessary context. The interrupt
routing model to route IRQs to EL3 is enabled only during STD SMC
processing. Thus the pre-emption of S-EL1 is disabled during Fast SMC
and Secure Interrupt processing.
A new build option TSPD_ROUTE_NS_INT_EL3 is introduced to change
the non secure interrupt target execution level to EL3.
FixesARM-software/tf-issues#225
Change-Id: Ia1e779fbbb6d627091e665c73fa6315637cfdd32
This patch extends the build option `USE_COHERENT_MEMORY` to
conditionally remove coherent memory from the memory maps of
all boot loader stages. The patch also adds necessary
documentation for coherent memory removal in firmware-design,
porting and user guides.
FixesARM-Software/tf-issues#106
Change-Id: I260e8768c6a5c2efc402f5804a80657d8ce38773
This patch moves the bakery locks out of coherent memory to normal memory.
This implies that the lock information needs to be placed on a separate cache
line for each cpu. Hence the bakery_lock_info_t structure is allocated in the
per-cpu data so as to minimize memory wastage. A similar platform per-cpu
data is introduced for the platform locks.
As a result of the above changes, the bakery lock api is completely changed.
Earlier, a reference to the lock structure was passed to the lock implementation.
Now a unique-id (essentially an index into the per-cpu data array) and an offset
into the per-cpu data for bakery_info_t needs to be passed to the lock
implementation.
Change-Id: I1e76216277448713c6c98b4c2de4fb54198b39e0
This patch fixes the incorrect value of the LENGTH attribute in
the linker scripts. This attribute must define the memory size, not
the limit address.
FixesARM-software/tf-issues#252
Change-Id: I328c38b9ec502debe12046a8912d7dfc54610c46
This patch resets the value of CNTVOFF_EL2 before exit to EL1 on
warm boot. This needs to be done if only the Trusted Firmware exits
to EL1 instead of EL2, otherwise the hypervisor would be responsible
for this.
FixesARM-software/tf-issues#240
Change-Id: I79d54831356cf3215bcf1f251c373bd8f89db0e0
This patch gathers miscellaneous minor fixes to the documentation, and comments
in the source code.
Change-Id: I631e3dda5abafa2d90f464edaee069a1e58b751b
Co-Authored-By: Soby Mathew <soby.mathew@arm.com>
Co-Authored-By: Dan Handley <dan.handley@arm.com>
This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.
Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab
This patch adds CPU core and cluster power down sequences to the CPU specific
operations framework introduced in a earlier patch. Cortex-A53, Cortex-A57 and
generic AEM sequences have been added. The latter is suitable for the
Foundation and Base AEM FVPs. A pointer to each CPU's operations structure is
saved in the per-cpu data so that it can be easily accessed during power down
seqeunces.
An optional platform API has been introduced to allow a platform to disable the
Accelerator Coherency Port (ACP) during a cluster power down sequence. The weak
definition of this function (plat_disable_acp()) does not take any action. It
should be overriden with a strong definition if the ACP is present on a
platform.
Change-Id: I8d09bd40d2f528a28d2d3f19b77101178778685d
This patch introduces a framework which will allow CPUs to perform
implementation defined actions after a CPU reset, during a CPU or cluster power
down, and when a crash occurs. CPU specific reset handlers have been implemented
in this patch. Other handlers will be implemented in subsequent patches.
Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.
Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956
This patch adds support for SYSTEM_OFF and SYSTEM_RESET PSCI
operations. A platform should export handlers to complete the
requested operation. The FVP port exports fvp_system_off() and
fvp_system_reset() as an example.
If the SPD provides a power management hook for system off and
system reset, then the SPD is notified about the corresponding
operation so it can do some bookkeeping. The TSPD exports
tspd_system_off() and tspd_system_reset() for that purpose.
Versatile Express shutdown and reset methods have been removed
from the FDT as new PSCI sys_poweroff and sys_reset services
have been added. For those kernels that do not support yet these
PSCI services (i.e. GICv3 kernel), the original dtsi files have
been renamed to *-no_psci.dtsi.
FixesARM-software/tf-issues#218
Change-Id: Ic8a3bf801db979099ab7029162af041c4e8330c8
This patch disables routing of external aborts from lower exception levels to
EL3 and ensures that a SError interrupt generated as a result of execution in
EL3 is taken locally instead of a lower exception level.
The SError interrupt is enabled in the TSP code only when the operation has not
been directly initiated by the normal world. This is to prevent the possibility
of an asynchronous external abort which originated in normal world from being
taken when execution is in S-EL1.
FixesARM-software/tf-issues#153
Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
Fix the following issues with the console log output:
* Make sure the welcome string is the first thing in the log output
(during normal boot).
* Prefix each message with the BL image name so it's clear which
BL the output is coming from.
* Ensure all output is wrapped in one of the log output macros so it can
be easily compiled out if necessary. Change some of the INFO() messages
to VERBOSE(), especially in the TSP.
* Create some extra NOTICE() and INFO() messages during cold boot.
* Remove all usage of \r in log output.
FixesARM-software/tf-issues#231
Change-Id: Ib24f7acb36ce64bbba549f204b9cde2dbb46c8a3
Secure ROM at address 0x0000_0000 is defined as FVP_TRUSTED_ROM
Secure RAM at address 0x0400_0000 is defined as FVP_TRUSTED_SRAM
Secure RAM at address 0x0600_0000 is defined as FVP_TRUSTED_DRAM
BLn_BASE and BLn_LIMIT definitions have been updated and are based on
these new memory regions.
The available memory for each bootloader in the linker script is
defined by BLn_BASE and BLn_LIMIT, instead of the complete memory
region.
TZROM_BASE/SIZE and TZRAM_BASE/SIZE are no longer required as part of
the platform porting.
FVP common definitions are defined in fvp_def.h while platform_def.h
contains exclusively (with a few exceptions) the definitions that are
mandatory in the porting guide. Therefore, platform_def.h now includes
fvp_def.h instead of the other way around.
Porting guide has been updated to reflect these changes.
Change-Id: I39a6088eb611fc4a347db0db4b8f1f0417dbab05
This patch adds support for BL3-2 initialization by asynchronous
method where BL3-1 transfers control to BL3-2 using world switch.
After BL3-2 initialization, it transfers control to BL3-3 via SPD
service handler. The SPD service handler initializes the CPU context
to BL3-3 entrypoint depending on the return function indentifier from
TSP initialization.
FixesARM-software/TF-issues#184
Change-Id: I7b135c2ceeb356d3bb5b6a287932e96ac67c7a34
The purpose of platform_is_primary_cpu() is to determine after reset
(BL1 or BL3-1 with reset handler) if the current CPU must follow the
cold boot path (primary CPU), or wait in a safe state (secondary CPU)
until the primary CPU has finished the system initialization.
This patch removes redundant calls to platform_is_primary_cpu() in
subsequent bootloader entrypoints since the reset handler already
guarantees that code is executed exclusively on the primary CPU.
Additionally, this patch removes the weak definition of
platform_is_primary_cpu(), so the implementation of this function
becomes mandatory. Removing the weak symbol avoids other
bootloaders accidentally picking up an invalid definition in case the
porting layer makes the real function available only to BL1.
The define PRIMARY_CPU is no longer mandatory in the platform porting
because platform_is_primary_cpu() hides the implementation details
(for instance, there may be platforms that report the primary CPU in
a system register). The primary CPU definition in FVP has been moved
to fvp_def.h.
The porting guide has been updated accordingly.
FixesARM-software/tf-issues#219
Change-Id: If675a1de8e8d25122b7fef147cb238d939f90b5e
This patch further optimizes the EL3 register state stored in
cpu_context. The 2 registers which are removed from cpu_context are:
* cntfrq_el0 is the system timer register which is writable
only in EL3 and it can be programmed during cold/warm boot. Hence
it need not be saved to cpu_context.
* cptr_el3 controls access to Trace, Floating-point, and Advanced
SIMD functionality and it is programmed every time during cold
and warm boot. The current BL3-1 implementation does not need to
modify the access controls during normal execution and hence
they are expected to remain static.
FixesARM-software/tf-issues#197
Change-Id: I599ceee3b73a7dcfd37069fd41b60e3d397a7b18
Assert a valid security state using the macro sec_state_is_valid().
Replace assert() with panic() in those cases that might arise
because of runtime errors and not programming errors.
Replace panic() with assert() in those cases that might arise
because of programming errors.
FixesARM-software/tf-issues#96
Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5
This patch adds the CPUECTLR_EL1 register and the CCI Snoop Control
register to the list of registers being reported when an unhandled
exception occurs.
Change-Id: I2d997f2d6ef3d7fa1fad5efe3364dc9058f9f22c
This patch reworks the crash reporting mechanism to further
optimise the stack and code size. The reporting makes use
of assembly console functions to avoid calling C Runtime
to report the CPU state. The crash buffer requirement is
reduced to 64 bytes with this implementation. The crash
buffer is now part of per-cpu data which makes retrieving
the crash buffer trivial.
Also now panic() will use crash reporting if
invoked from BL3-1.
FixesARM-software/tf-issues#199
Change-Id: I79d27a4524583d723483165dc40801f45e627da5
This patch reworks the manner in which the M,A, C, SA, I, WXN & EE bits of
SCTLR_EL3 & SCTLR_EL1 are managed. The EE bit is cleared immediately after reset
in EL3. The I, A and SA bits are set next in EL3 and immediately upon entry in
S-EL1. These bits are no longer managed in the blX_arch_setup() functions. They
do not have to be saved and restored either. The M, WXN and optionally the C
bit are set in the enable_mmu_elX() function. This is done during both the warm
and cold boot paths.
FixesARM-software/tf-issues#226
Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069
Print out Trusted Firmware version at runtime at each BL stage.
Message consists of TF version as defined statically in the Makefile
(e.g. v0.4), build mode (debug|release) and a customizable build
string:
1. By defining BUILD_STRING in command line when building TF
2. Default string is git commit ID
3. Empty if git meta-data is not available
FixesARM-software/tf-issues#203
Change-Id: I5c5ba438f66ab68810427d76b49c5b9177a957d6
This patch implements a "tf_printf" which supports only the commonly
used format specifiers in Trusted Firmware, which uses a lot less
stack space than the stdlib printf function.
FixesARM-software/tf-issues#116
Change-Id: I7dfa1944f4c1e634b3e2d571f49afe02d109a351
This patch uses stacks allocated in normal memory to enable the MMU early in the
warm boot path thus removing the dependency on stacks allocated in coherent
memory. Necessary cache and stack maintenance is performed when a cpu is being
powered down and up. This avoids any coherency issues that can arise from
reading speculatively fetched stale stack memory from another CPUs cache. These
changes affect the warm boot path in both BL3-1 and BL3-2.
The EL3 system registers responsible for preserving the MMU state are not saved
and restored any longer. Static values are used to program these system
registers when a cpu is powered on or resumed from suspend.
Change-Id: I8357e2eb5eb6c5f448492c5094b82b8927603784
This patch reworks the cold boot path across the BL1, BL2, BL3-1 and BL3-2 boot
loader stages to not use stacks allocated in coherent memory for early platform
setup and enabling the MMU. Stacks allocated in normal memory are used instead.
Attributes for stack memory change from nGnRnE when the MMU is disabled to
Normal WBWA Inner-shareable when the MMU and data cache are enabled. It is
possible for the CPU to read stale stack memory after the MMU is enabled from
another CPUs cache. Hence, it is unsafe to turn on the MMU and data cache while
using normal stacks when multiple CPUs are a part of the same coherency
domain. It is safe to do so in the cold boot path as only the primary cpu
executes it. The secondary cpus are in a quiescent state.
This patch does not remove the allocation of coherent stack memory. That is done
in a subsequent patch.
Change-Id: I12c80b7c7ab23506d425c5b3a8a7de693498f830
Vikram Kanigiri
Achin Gupta
Andrew Thoelke
Soby Mathew
danh-arm
Sandrine Bailleux
Kévin Petit
Yatharth Kochar
Juan Castillo
Jens Wiklander