The original table handling code does not always verify checksums before
installing a table, this is because code to achieve this must be
implemented here and there in the redundant code blocks.
There are two stages during table initialization:
1. "INSTALLED" after acpi_tb_install_table() and acpi_tb_override_table(),
struct acpi_table_desc.Pointer is ensured to be NULL. This can be safely used
during OSPM's early boot stage.
2. "VALIDATED" after acpi_tb_validate_table(), struct acpi_table_desc.Pointer is
ensured to be not NULL. This must not be used during OSPM's early boot
stage.
This patch changes acpi_tb_add_table() into an early boot safe API to reduce
code redundancies by changing the table state that is returned by this
function from "VALIDATED" to "INSTALLED". Then the table verification
code can be done in a single place. Originally, the acpi_tb_add_table() can
only be used by dynamic table loadings that are executed after early boot
stage, it cannot be used by static table loadings that are executed in
early boot stage as:
1. The address of the table is a virtual address either maintained by
OSPMs who call acpi_load_table() or by ACPICA whenever "Load" or
"LoadTable" opcodes are executed, while during early boot stage,
physical address of the table should be used for table loading.
2. The API will ensure the state of the loaded table to be "VALIDATED"
while during early boot stage, tables maintained by root table list
should be kept as "INSTALLED".
To achieve this:
1. Rename acpi_tb_install_table() to acpi_tb_install_fixed_table() as it only
applies to DSDT/FACS installation. Rename acpi_tb_add_table() to
acpi_tb_install_non_fixed_table() as it will be applied to the installation
of the rest kinds of tables.
2. Introduce acpi_tb_install_table(), acpi_tb_install_and_override_table to collect
redudant code where their invocations actually have slight differences.
1. acpi_tb_install_table() is used to fill an struct acpi_table_desc where the
table length is known to the caller.
2. acpi_tb_install_and_override_table() is used to perform necessary
overriding before installation.
3. Change a parameter of acpi_tb_install_non_fixed_table() from struct acpi_table_desc
to acpi_physical_address to allow it to be invoked by static table
loadings. Also cleanup acpi_ex_load_op() and acpi_load_table() to accomodate
to the parameter change.
4. Invoke acpi_tb_install_non_fixed_table() for all table loadings other than
DSDT/FACS in acpi_tb_parse_root_table() to improve code maintainability
(logics are collected in the single function). Also delete useless code
from acpi_tb_parse_root_table().
5. Remove all acpi_tb_validate_table() from acpi_tb_install_non_fixed_table() and
acpi_tb_install_fixed_table() so that the table descriptor is kept in the
state of "INSTALLED" but not "VALIDATED" after returning from these
functions.
6. Introduce temporary struct acpi_table_desc (new_table_desc/old_table_desc) into
the functions to indicate a table descriptor that is not maintained by
acpi_gbl_root_table_list. Introduce acpi_tb_acquire_temporal_table() and
acpi_tb_release_temporal_table() to handle the use cases of such temporal
tables. They are only used for verified installation.
7. Introduce acpi_tb_verify_table() to validate table and verify table
checksum, also remove table checksum verification from
acpi_tb_validate_table(). Invoke acpi_tb_validate_table() in the functions
that will convert a table into "LOADED" state or invoke it from
acpi_get_table_XXX() APIs. Invoke acpi_tb_verify_table() on temporary
struct acpi_table_desc(s) that are going to be "INSTALLED".
8. Change acpi_tb_override_table() logic so that a temporary struct acpi_table_desc
will be overridden before installtion, this makes code simpler.
After applying the patch, tables are always installed after being
overridden and the table checksums are always verified before installation.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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