Read-only xlat tables for BL31 memory ...

This patch introduces a build flag which allows the xlat tables
to be mapped in a read-only region within BL31 memory. It makes it
much harder for someone who has acquired the ability to write to
arbitrary secure memory addresses to gain control of the
translation tables.

The memory attributes of the descriptors describing the tables
themselves are changed to read-only secure data. This change
happens at the end of BL31 runtime setup. Until this point, the
tables have read-write permissions. This gives a window of
opportunity for changes to be made to the tables with the MMU on
(e.g. reclaiming init code). No changes can be made to the tables
with the MMU turned on from this point onwards. This change is also
enabled for sp_min and tspd.

To make all this possible, the base table was moved to .rodata. The
penalty we pay is that now .rodata must be aligned to the size of
the base table (512B alignment). Still, this is better than putting
the base table with the higher level tables in the xlat_table
section, as that would cost us a full 4KB page.

Changing the tables from read-write to read-only cannot be done with
the MMU on, as the break-before-make sequence would invalidate the
descriptor which resolves the level 3 page table where that very
descriptor is located. This would make the translation required for
writing the changes impossible, generating an MMU fault.

The caches are also flushed.

Signed-off-by: Petre-Ionut Tudor <petre-ionut.tudor@arm.com>
Change-Id: Ibe5de307e6dc94c67d6186139ac3973516430466

xlat: Fix compatibility between v1 and v2 ...

There are several platforms using arm_setup_page_tables(), which is
supposed to be Arm platform only. This creates several dependency
problems between platforms.

This patch adds the definition XLAT_TABLES_LIB_V2 to the xlat tables lib
v2 makefile. This way it is possible to detect from C code which version
is being used and include the correct header.

The file arm_xlat_tables.h has been renamed to xlat_tables_compat.h and
moved to a common folder. This way, when in doubt, this header can be
used to guarantee compatibility, as it includes the correct header based
on XLAT_TABLES_LIB_V2.

This patch also removes the usage of ARM_XLAT_TABLES_V1 from QEMU (so
that is now locked in xlat lib v2) and ZynqMP (where it was added as a
workaround).

Change-Id: Ie1e22a23b44c549603d1402a237a70d0120d3e04
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

xlat v2: Remove architectural headers ...

They only contained one function that is easily integrated in the private
library header and the existing architectural C files.

This also helps making the library more portable, as the Makefile of the
library now doesn't use the variable INCLUDES, which is specific to this
codebase and doesn't respect the namespace of the library.

Change-Id: I22228e6a97e9b4f346f5cd8947609263e8df71d8
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

xlat v2: Split code into separate files ...

Instead of having one big file with all the code, it's better to have
a few smaller files that are more manageable:

- xlat_tables_core.c: Code related to the core functionality of the
  library (map and unmap regions, initialize xlat context).
- xlat_tables_context.c: Instantiation of the active image context
  as well as APIs to manipulate it.
- xlat_tables_utils.c: Helper code that isn't part of the core
  functionality (change attributes, debug print messages).

Change-Id: I3ea956fc1afd7473c0bb5e7c6aab3b2e5d88c711
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

xlat v2: Split MMU setup and enable ...

At present, the function provided by the translation library to enable
MMU constructs appropriate values for translation library, and programs
them to the right registers. The construction of initial values,
however, is only required once as both the primary and secondaries
program the same values.

Additionally, the MMU-enabling function is written in C, which means
there's an active stack at the time of enabling MMU. On some systems,
like Arm DynamIQ, having active stack while enabling MMU during warm
boot might lead to coherency problems.

This patch addresses both the above problems by:

  - Splitting the MMU-enabling function into two: one that sets up
    values to be programmed into the registers, and another one that
    takes the pre-computed values and writes to the appropriate
    registers. With this, the primary effectively calls both functions
    to have the MMU enabled, but secondaries only need to call the
    latter.

  - Rewriting the function that enables MMU in assembly so that it
    doesn't use stack.

This patch fixes a bunch of MISRA issues on the way.

Change-Id: I0faca97263a970ffe765f0e731a1417e43fbfc45
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

xlat: Add support for EL0 and EL1 mappings ...

This patch introduces the ability of the xlat tables library to manage
EL0 and EL1 mappings from a higher exception level.

Attributes MT_USER and MT_PRIVILEGED have been added to allow the user
specify the target EL in the translation regime EL1&0.

REGISTER_XLAT_CONTEXT2 macro is introduced to allow creating a
xlat_ctx_t that targets a given translation regime (EL1&0 or EL3).

A new member is added to xlat_ctx_t to represent the translation regime
the xlat_ctx_t manages. The execute_never mask member is removed as it
is computed from existing information.

Change-Id: I95e14abc3371d7a6d6a358cc54c688aa9975c110
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Co-authored-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Co-authored-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

xlat lib v2: Expose *_ctx() APIs ...

In a previous patch, the xlat_ctx_t type has been made public.
This patch now makes the *_ctx() APIs public.

Each API now has a *_ctx() variant. Most of them were already implemented
and this patch just makes them public. However, some of them were missing
so this patch introduces them.

Now that all these APIs are public, there's no good reason for splitting
them accross 2 files (xlat_tables_internal.c and xlat_tables_common.c).
Therefore, this patch moves all code into xlat_tables_internal.c and
removes xlat_tables_common.c. It removes it from the library's makefile
as well.

This last change introduces a compatibility break for platform ports
that specifically include the xlat_tables_common.c file instead of
including the library's Makefile. The UniPhier platform makefile has
been updated to now omit this file from the list of source files.

The prototype of mmap_add_region_ctx() has been slightly changed. The
mmap_region_t passed in argument needs to be constant because it gets
called from map_add(), which receives a constant region. The former
implementation of mmap_add() used to cast the const qualifier away,
which is not a good practice.

Also remove init_xlation_table(), which was a sub-function of
init_xlat_tables(). Now there's just init_xlat_tables() (and
init_xlat_tables_ctx()). Both names were too similar, which was
confusing. Besides, now that all the code is in a single file,
it's no longer needed to have 2 functions for that.

Change-Id: I4ed88c68e44561c3902fbebb89cb197279c5293b
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Add version 2 of xlat tables library ...

The folder lib/xlat_tables_v2 has been created to store a new version
of the translation tables library for further modifications in patches
to follow. At the moment it only contains a basic implementation that
supports static regions.

This library allows different translation tables to be modified by
using different 'contexts'. For now, the implementation defaults to
the translation tables used by the current image, but it is possible
to modify other tables than the ones in use.

Added a new API to print debug information for the current state of
the translation tables, rather than printing the information while
the tables are being created. This allows subsequent debug printing
of the xlat tables after they have been changed, which will be useful
when dynamic regions are implemented in a patch to follow.

The common definitions stored in `xlat_tables.h` header have been moved
to a new file common to both versions, `xlat_tables_defs.h`.

All headers related to the translation tables library have been moved to
a the subfolder `xlat_tables`.

Change-Id: Ia55962c33e0b781831d43a548e505206dffc5ea9
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>