SDEI: Make dispatches synchronous ...

SDEI event dispatches currently only sets up the Non-secure context
before returning to the caller. The actual dispatch only happens upon
exiting EL3 next time.

However, for various error handling scenarios, it's beneficial to have
the dispatch happen synchronously. I.e. when receiving SDEI interrupt,
or for a successful sdei_dispatch_event() call, the event handler is
executed; and upon the event completion, dispatcher execution resumes
after the point of dispatch. The jump primitives introduced in the
earlier patch facilitates this feature.

With this patch:

  - SDEI interrupts and calls to sdei_dispatch_event prepares the NS
    context for event dispatch, then sets a jump point, and immediately
    exits EL3. This results in the client handler executing in
    Non-secure.

  - When the SDEI client completes the dispatched event, the SDEI
    dispatcher does a longjmp to the jump pointer created earlier. For
    the caller of the sdei_dispatch_event() in particular, this would
    appear as if call returned successfully.

The dynamic workaround for CVE_2018_3639 is slightly shifted around as
part of related minor refactoring. It doesn't affect the workaround
functionality.

Documentation updated.

NOTE: This breaks the semantics of the explicit dispatch API, and any
exiting usages should be carefully reviewed.

Change-Id: Ib9c876d27ea2af7fb22de49832e55a0da83da3f9
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Determine client EL from NS context's SCR_EL3 ...

Currently, the dispatcher reads from SCR_EL3 register directly to
determine the EL of SDEI client. This is with the assumption that
SCR_EL3 is not modified throughout. However, with RAS work flows, it's
possible that SCR_EL3 register contains values corresponding to Secure
world, and therefore EL determination can go wrong. To mitigate this,
always read the register from the saved Non-secure context.

Change-Id: Ic85e4021deb18eb58757f676f9a001174998543a
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SDEI: Allow platforms to define explicit events ...

The current macros only allow to define dynamic and statically-bound
SDEI events. However, there ought be a mechanism to define SDEI events
that are explicitly dispatched; i.e., events that are dispatched as a
result of a previous secure interrupt or other exception

This patch introduces SDEI_EXPLICIT_EVENT() macro to define an explicit
event. They must be placed under private mappings. Only the priority
flags are allowed to be additionally specified.

Documentation updated.

Change-Id: I2e12f5571381195d6234c9dfbd5904608ad41db3
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

SPM: Refactor entry and exit of the SP ...

Only use synchronous calls to enter the Secure Partition in order to
simplify the SMC handling code.

Change-Id: Ia501a045585ee0836b9151141ad3bd11d0971be2
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

xlat v2: Introduce xlat granule size helpers ...

The function xlat_arch_is_granule_size_supported() can be used to check
if a specific granule size is supported. In Armv8, AArch32 only supports
4 KiB pages. AArch64 supports 4 KiB, 16 KiB or 64 KiB depending on the
implementation, which is detected at runtime.

The function xlat_arch_get_max_supported_granule_size() returns the max
granule size supported by the implementation.

Even though right now they are only used by SPM, they may be useful in
other places in the future. This patch moves the code currently in SPM
to the xlat tables lib so that it can be reused.

Change-Id: If54624a5ecf20b9b9b7f38861b56383a03bbc8a4
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Initialize SP args as expected by cm library ...

In the context management library, cm_setup_context() takes the
information in ep_info to fill the registers x0-x7. This patch replaces
the current code that sets them manually by the correct initialization
code.

Change-Id: Id1fdf4681b154026c2e3af1f9b05b19582b7d16d
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SDEI: Ensure SDEI handler executes with CVE-2018-3639 mitigation enabled ...

When dynamic mitigation is used, the SDEI handler is required to
execute with the mitigation enabled by default, regardless of the
mitigation state for lower ELs.  This means that if the kernel or
hypervisor explicitly disables the mitigation and then later when the
event is dispatched, the dispatcher will remember the mitigation state
for the lower ELs but force the mitigation to be on during the SDEI
handler execution.  When the SDEI handler returns, it will restore the
mitigation state.

This behaviour is described in "Firmware interfaces for mitigating
cache speculation vulnerabilities System Software on Arm Systems"[0].

[0] https://developer.arm.com/cache-speculation-vulnerability-firmware-specification

Change-Id: I8dd60b736be0aa9e832b0f92d67a401fdeb417f4
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

SPM: Extract code out of the SMC handler ...

Simplify the code of the SMC handler by extracting the code of
SP_EVENT_COMPLETE and MM_COMMUNICATE.

Change-Id: I9250a3f5e4b807b35c9d044592c1074a45ab9a07
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Replace SP init flag by generic state enum ...

Instead of just knowing if the Secure Partition is being initialized or
not, this generic state enum can be used to tell if the Secure Partition
is busy and to add more states in the future if needed.

Also, the spinlock of the secure_partition_context_t structure now only
protects against concurrent accesses to the state of the secure
partition. Previously, it used to lock down the whole structure, thus
preventing one CPU to access any of its fields while another CPU was
executing the partition.

Change-Id: I51215328e2ca8ea2452f92e4a1cb237415958b22
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Shorten names of types and functions ...

The current internal names are too long, which makes it hard to write
code as many lines overflow the limit and need to be split, which may
not help the reader.

Change-Id: I072bdc8f3dd125255063ffa7f02500e5228fc9a1
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Move xlat-related functions to separate file ...

This is done in order to make it easier to read the file spm_main.c.

Change-Id: I21e765154c1682a319a3bc47a19a42fd736e910e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Move all SP-related info to SP context struct ...

Move all information related to a Secure Partition to the struct
secure_partition_context_t.

This requires an in-depth refactor because most of the previous code of
SPM relied on global information.

Change-Id: I0a23e93817dcc191ce1d7506b8bc671d376123c4
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Do not trap S-EL0 access to SVE/SIMD/FP regs ...

This allows secure partitions to access these registers. This is
needed in some cases. For example, it has been reported that in order
to implement secure storage services, a secure partition needs to
encrypt/decrypt some authentication variables, which requires FP/SIMD
support.

Note that SPM will not do any saving/restoring of these registers on
behalf of the SP. This falls under the SP's responsibility.

Also note that if the SP gets preempted, it might not get a chance to
save/restore FP/SIMD registers first. This patch does not address this
problem. It only serves as a temporary solution to unblock development
on the secure partition side.

Change-Id: I3b8ccdebdac0219f6ac96ad66ab2be0be8374ad3
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Fix some MISRA defects in SPM code ...

Change-Id: I989c1f4aef8e3cb20d5d19e6347575e6449bb60b
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Merge pull request #1313 from jonathanwright-ARM/jw/MISRA-switch-statements ...

Fix switch statements to comply with MISRA rules

Clean usage of void pointers to access symbols ...

Void pointers have been used to access linker symbols, by declaring an
extern pointer, then taking the address of it. This limits symbols
values to aligned pointer values. To remove this restriction an
IMPORT_SYM macro has been introduced, which declares it as a char
pointer and casts it to the required type.

Change-Id: I89877fc3b13ed311817bb8ba79d4872b89bfd3b0
Signed-off-by: Joel Hutton <Joel.Hutton@Arm.com>

services: fix switch statements to comply with MISRA rules ...

Ensure (where possible) that switch statements in services comply with
MISRA rules 16.1 - 16.7.

Change-Id: I47bf6ed4a026201e6fe125ce51842482e99e8bb0
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>

Rename 'smcc' to 'smccc' ...

When the source code says 'SMCC' it is talking about the SMC Calling
Convention. The correct acronym is SMCCC. This affects a few definitions
and file names.

Some files have been renamed (smcc.h, smcc_helpers.h and smcc_macros.S)
but the old files have been kept for compatibility, they include the
new ones with an ERROR_DEPRECATED guard.

Change-Id: I78f94052a502436fdd97ca32c0fe86bd58173f2f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Merge pull request #1282 from robertovargas-arm/misra-changes ...

Misra changes

Fix MISRA rule 8.4 in common code ...

Rule 8.4: A compatible declaration shall be visible when
          an object or function with external linkage is defined.

Change-Id: I26e042cb251a6f9590afa1340fdac73e42f23979
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

SDEI: Pop dispatch context only after error checking ...

Currently, when the client attempts to do SDEI_EVENT_COMPLETE or
SDEI_EVENT_COMPLETE_AND_RESUME, the dispatcher pops off the outstanding
dispatch context for sanity check. There are however other checks
following this, which could potentially return failure. If that happens,
by popping the context, the dispatcher has inadvertently discarded a
valid context.

This patch fixes this bug by inspecting (not actually popping) the
outstanding context. The context is popped only after all error checks
are completed.

Change-Id: Ie199f6442f871a8177a8247a0c646543bad76d21
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Ensure the correct execution of TLBI instructions ...

After executing a TLBI a DSB is needed to ensure completion of the
TLBI.

rk3328: The MMU is allowed to load TLB entries for as long as it is
enabled. Because of this, the correct place to execute a TLBI is right
after disabling the MMU.

Change-Id: I8280f248d10b49a8c354a4ccbdc8f8345ac4c170
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Remove URLs from comments ...

This fixes all defects according to MISRA Rule 3.1: "The character
sequences /* and // shall not be used within a comment". This affects
all URLs in comments, so they have been removed:

- The link in `sdei_state.c` can also be found in the documentation file
  `docs/sdei.rst`.

- The bug that the file `io_fip.c` talks about doesn't affect the
  currently supported version of GCC, so it doesn't make sense to keep
  the comment. Note that the version of GCC officially supported is the
  one that comes with Linaro Release 17.10, which is GCC 6.2.

- The link in `tzc400.c` was broken, and it didn't correctly direct to
  the Technical Reference Manual it should. The link has been replaced
  by the title of the document, which is more convenient when looking
  for the document.

Change-Id: I89f60c25f635fd4c008a5d3a14028f814c147bbe
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Fix version header definitions ...

Rename SP_VERSION macros to MM_VERSION, which is the name used in the MM
specification [1]. Also, a few more helper macros have been added.

MM-specific definitions have been moved to their own header file.

[1] http://infocenter.arm.com/help/topic/com.arm.doc.den0060a/DEN0060A_ARM_MM_Interface_Specification.pdf

Change-Id: Ia10e48c7e81a7a1f5eeca29a5270cae740a4a88a
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Allow secondary CPUs to use the Secure Partition ...

The Secure Partition should be able to be used from any CPU, not just
the lead one. This patch point the secure contexts of all secondary
CPUs to the same one used by the lead CPU for the Secure Partition. This
way, they can also use it.

In order to prevent more than one CPU from using the Secure Partition at
the same time, a lock has been added.

Change-Id: Ica76373127c3626498b06c558a4874ce72201ff7
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Move initialization flag to context struct ...

Whether a Secure Partition is being initialized or not is something
related to that specific partition, so it should be saved with the
rest of the information related to it.

Change-Id: Ie8a780f70df83fb03ef9c01ba37960208d9b5319
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Fix MM_COMMUNICATE_AARCH32/64 parameters ...

This partially reverts commit d6b532b50f8, keeping only the fixes to
the assertions. The changes related to the order of arguments passed
to the secure partition were not correct and violated the
specification of the SP_EVENT_COMPLETE SMC.

This patch also improves the MM_COMMUNICATE argument validation.  The
cookie argument, as it comes from normal world, can't be trusted and thus
needs to always be validated at run time rather than using an assertion.

Also validate the communication buffer address and return
INVALID_PARAMETER if it is zero, as per the MM specification.

Fix a few typos in comments and use the "secure partition" terminology
rather than "secure payload".

Change-Id: Ice6b7b5494b729dd44611f9a93d362c55ab244f7
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Merge pull request #1187 from antonio-nino-diaz-arm/an/spm-xlat-dram ...

SPM: Move S-EL1/S-EL0 xlat tables to TZC DRAM

Merge pull request #1184 from antonio-nino-diaz-arm/an/bl31-in-dram ...

fvp: Disable SYSTEM_SUSPEND when ARM_BL31_IN_DRAM

Merge pull request #1183 from jeenu-arm/sdei-reset-fix ...

SDEI: Fix return value of reset calls