The only case in which regions can now overlap is if they are
identity mapped or they have the same virtual to physical address
offset (identity mapping is just a particular case of the latter).
They must overlap completely (i.e. one of them must be completely
inside the other one) and not cover the same area.
This allow future enhancements to the xlat_tables library without
having to support unnecessarily complex edge cases.
Outer regions are now sorted by mmap_add_region() before inner
regions with the same base virtual address for consistency: all
regions contained inside another one must be placed after the outer
one in the list.
If an inner region has the same attributes as the outer ones it will
be merged when creating the tables with init_xlation_table(). This
cannot be done as regions are added because there may be cases where
adding a region makes previously mergeable regions no longer
mergeable.
If the attributes of an inner region are different than the outer
region, new pages will be generated regardless of how "restrictive"
they are. For example, RO memory is more restrictive than RW. The
old implementation would give priority to RO if there is an overlap,
the new one doesn't.
NOTE: THIS IS THEORETICALLY A COMPATABILITY BREAK FOR PLATFORMS THAT
USE THE XLAT_TABLES LIBRARY IN AN UNEXPECTED WAY. PLEASE RAISE A
TF-ISSUE IF YOUR PLATFORM IS AFFECTED.
Change-Id: I75fba5cf6db627c2ead70da3feb3cc648c4fe2af
The AArch32 long descriptor format and the AArch64 descriptor format
correspond to each other which allows possible sharing of xlat_tables
library code between AArch64 and AArch32. This patch refactors the
xlat_tables library code to seperate the common functionality from
architecture specific code. Prior to this patch, all of the xlat_tables
library code were in `lib/aarch64/xlat_tables.c` file. The refactored code
is now in `lib/xlat_tables/` directory. The AArch64 specific programming
for xlat_tables is in `lib/xlat_tables/aarch64/xlat_tables.c` and the rest
of the code common to AArch64 and AArch32 is in
`lib/xlat_tables/xlat_tables_common.c`. Also the data types used in
xlat_tables library APIs are reworked to make it compatible between AArch64
and AArch32.
The `lib/aarch64/xlat_tables.c` file now includes the new xlat_tables
library files to retain compatibility for existing platform ports.
The macros related to xlat_tables library are also moved from
`include/lib/aarch64/arch.h` to the header `include/lib/xlat_tables.h`.
NOTE: THE `lib/aarch64/xlat_tables.c` FILE IS DEPRECATED AND PLATFORM PORTS
ARE EXPECTED TO INCLUDE THE NEW XLAT_TABLES LIBRARY FILES IN THEIR MAKEFILES.
Change-Id: I3d17217d24aaf3a05a4685d642a31d4d56255a0f
Antonio Nino Diaz
Soby Mathew