ACPICA: Use original pointer for virtual origin tables

ACPICA commit dfa3feffa8f760b686207d09dc880cd2f26c72af

Currently the pointer to the table is cast to acpi_physical_address and
later cast back to a pointer to be dereferenced. Whether or not this is
supported is implementation-defined.

On CHERI, and thus Arm's experimental Morello prototype architecture,
pointers are represented as capabilities, which are unforgeable bounded
pointers, providing always-on fine-grained spatial memory safety. This
means that any pointer cast to a plain integer will lose all its
associated metadata, and when cast back to a pointer it will give a
null-derived pointer (one that has the same metadata as null but an
address equal to the integer) that will trap on any dereference. As a
result, this is an implementation where acpi_physical_address cannot be
used as a hack to store real pointers.

Thus, alter the lifecycle of table descriptors. Internal physical tables
keep the current behaviour where only the address is set on install, and
the pointer is set on acquire. Virtual tables (internal and external)
now store the pointer on initialisation and use that on acquire (which
will redundantly set *table_ptr to itself, but changing that is both
unnecessary and overly complicated as acpi_tb_acquire_table is called with
both a pointer to a variable and a pointer to Table->Pointer itself).

This requires propagating the (possible) table pointer everywhere in
order to make sure pointers make it through to acpi_tb_acquire_temp_table,
which requires a change to the acpi_install_table interface. Instead of
taking an ACPI_PHYSADDR_TYPE and a boolean indicating whether it's
physical or virtual, it is now split into acpi_install_table (that takes
an external virtual table pointer) and acpi_install_physical_table (that
takes an ACPI_PHYSADDR_TYPE for an internal physical table address).
This also has the benefit of providing a cleaner API.

Link: https://github.com/acpica/acpica/commit/dfa3feff
Signed-off-by: Bob Moore <robert.moore@intel.com>
[ rjw: Adjust the code in tables.c to match interface changes ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
index 5174abfa8af9..047bd094ba68 100644
--- a/drivers/acpi/acpica/tbfadt.c
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -313,7 +313,7 @@ void acpi_tb_parse_fadt(void)
 	acpi_tb_install_standard_table((acpi_physical_address)acpi_gbl_FADT.
 				       Xdsdt,
 				       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
-				       FALSE, TRUE, &acpi_gbl_dsdt_index);
+				       NULL, FALSE, TRUE, &acpi_gbl_dsdt_index);
 
 	/* If Hardware Reduced flag is set, there is no FACS */
 
@@ -322,14 +322,14 @@ void acpi_tb_parse_fadt(void)
 			acpi_tb_install_standard_table((acpi_physical_address)
 						       acpi_gbl_FADT.facs,
 						       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
-						       FALSE, TRUE,
+						       NULL, FALSE, TRUE,
 						       &acpi_gbl_facs_index);
 		}
 		if (acpi_gbl_FADT.Xfacs) {
 			acpi_tb_install_standard_table((acpi_physical_address)
 						       acpi_gbl_FADT.Xfacs,
 						       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
-						       FALSE, TRUE,
+						       NULL, FALSE, TRUE,
 						       &acpi_gbl_xfacs_index);
 		}
 	}