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>

drivers/acpi/acpica/actables.h

@@ -35,7 +35,8 @@ acpi_tb_init_table_descriptor(struct acpi_table_desc *table_desc,
 
 acpi_status
 acpi_tb_acquire_temp_table(struct acpi_table_desc *table_desc,
-			   acpi_physical_address address, u8 flags);
+			   acpi_physical_address address,
+			   u8 flags, struct acpi_table_header *table);
 
 void acpi_tb_release_temp_table(struct acpi_table_desc *table_desc);
 
@@ -86,6 +87,7 @@ acpi_tb_release_table(struct acpi_table_header *table,
 acpi_status
 acpi_tb_install_standard_table(acpi_physical_address address,
 			       u8 flags,
+			       struct acpi_table_header *table,
 			       u8 reload, u8 override, u32 *table_index);
 
 void acpi_tb_uninstall_table(struct acpi_table_desc *table_desc);
@@ -95,7 +97,9 @@ acpi_tb_load_table(u32 table_index, struct acpi_namespace_node *parent_node);
 
 acpi_status
 acpi_tb_install_and_load_table(acpi_physical_address address,
-			       u8 flags, u8 override, u32 *table_index);
+			       u8 flags,
+			       struct acpi_table_header *table,
+			       u8 override, u32 *table_index);
 
 acpi_status acpi_tb_unload_table(u32 table_index);
 

drivers/acpi/acpica/exconfig.c

@@ -411,7 +411,7 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
 	acpi_ex_exit_interpreter();
 	status = acpi_tb_install_and_load_table(ACPI_PTR_TO_PHYSADDR(table),
 						ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
-						TRUE, &table_index);
+						table, TRUE, &table_index);
 	acpi_ex_enter_interpreter();
 	if (ACPI_FAILURE(status)) {
 

drivers/acpi/acpica/tbdata.c

@@ -89,14 +89,27 @@ acpi_tb_init_table_descriptor(struct acpi_table_desc *table_desc,
 {
 
 	/*
-	 * Initialize the table descriptor. Set the pointer to NULL, since the
-	 * table is not fully mapped at this time.
+	 * Initialize the table descriptor. Set the pointer to NULL for external
+	 * tables, since the table is not fully mapped at this time.
 	 */
 	memset(table_desc, 0, sizeof(struct acpi_table_desc));
 	table_desc->address = address;
 	table_desc->length = table->length;
 	table_desc->flags = flags;
 	ACPI_MOVE_32_TO_32(table_desc->signature.ascii, table->signature);
+
+	switch (table_desc->flags & ACPI_TABLE_ORIGIN_MASK) {
+	case ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL:
+	case ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL:
+
+		table_desc->pointer = table;
+		break;
+
+	case ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL:
+	default:
+
+		break;
+	}
 }
 
 /*******************************************************************************
@@ -132,9 +145,7 @@ acpi_tb_acquire_table(struct acpi_table_desc *table_desc,
 	case ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL:
 	case ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL:
 
-		table = ACPI_CAST_PTR(struct acpi_table_header,
-				      ACPI_PHYSADDR_TO_PTR(table_desc->
-							   address));
+		table = table_desc->pointer;
 		break;
 
 	default:
@@ -196,6 +207,8 @@ acpi_tb_release_table(struct acpi_table_header *table,
  * PARAMETERS:  table_desc          - Table descriptor to be acquired
  *              address             - Address of the table
  *              flags               - Allocation flags of the table
+ *              table               - Pointer to the table (required for virtual
+ *                                    origins, optional for physical)
  *
  * RETURN:      Status
  *
@@ -208,49 +221,52 @@ acpi_tb_release_table(struct acpi_table_header *table,
 
 acpi_status
 acpi_tb_acquire_temp_table(struct acpi_table_desc *table_desc,
-			   acpi_physical_address address, u8 flags)
+			   acpi_physical_address address,
+			   u8 flags, struct acpi_table_header *table)
 {
-	struct acpi_table_header *table_header;
+	u8 mapped_table = FALSE;
 
 	switch (flags & ACPI_TABLE_ORIGIN_MASK) {
 	case ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL:
 
 		/* Get the length of the full table from the header */
 
-		table_header =
-		    acpi_os_map_memory(address,
-				       sizeof(struct acpi_table_header));
-		if (!table_header) {
-			return (AE_NO_MEMORY);
+		if (!table) {
+			table =
+			    acpi_os_map_memory(address,
+					       sizeof(struct
+						      acpi_table_header));
+			if (!table) {
+				return (AE_NO_MEMORY);
+			}
+
+			mapped_table = TRUE;
 		}
 
-		acpi_tb_init_table_descriptor(table_desc, address, flags,
-					      table_header);
-		acpi_os_unmap_memory(table_header,
-				     sizeof(struct acpi_table_header));
-		return (AE_OK);
+		break;
 
 	case ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL:
 	case ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL:
 
-		table_header = ACPI_CAST_PTR(struct acpi_table_header,
-					     ACPI_PHYSADDR_TO_PTR(address));
-		if (!table_header) {
-			return (AE_NO_MEMORY);
+		if (!table) {
+			return_ACPI_STATUS(AE_BAD_PARAMETER);
 		}
 
-		acpi_tb_init_table_descriptor(table_desc, address, flags,
-					      table_header);
-		return (AE_OK);
+		break;
 
 	default:
 
-		break;
+		/* Table is not valid yet */
+
+		return (AE_NO_MEMORY);
 	}
 
-	/* Table is not valid yet */
+	acpi_tb_init_table_descriptor(table_desc, address, flags, table);
+	if (mapped_table) {
+		acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
+	}
 
-	return (AE_NO_MEMORY);
+	return (AE_OK);
 }
 
 /*******************************************************************************
@@ -335,7 +351,19 @@ void acpi_tb_invalidate_table(struct acpi_table_desc *table_desc)
 
 	acpi_tb_release_table(table_desc->pointer, table_desc->length,
 			      table_desc->flags);
-	table_desc->pointer = NULL;
+
+	switch (table_desc->flags & ACPI_TABLE_ORIGIN_MASK) {
+	case ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL:
+
+		table_desc->pointer = NULL;
+		break;
+
+	case ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL:
+	case ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL:
+	default:
+
+		break;
+	}
 
 	return_VOID;
 }
@@ -959,6 +987,9 @@ acpi_tb_load_table(u32 table_index, struct acpi_namespace_node *parent_node)
  *
  * PARAMETERS:  address                 - Physical address of the table
  *              flags                   - Allocation flags of the table
+ *              table                   - Pointer to the table (required for
+ *                                        virtual origins, optional for
+ *                                        physical)
  *              override                - Whether override should be performed
  *              table_index             - Where table index is returned
  *
@@ -970,7 +1001,9 @@ acpi_tb_load_table(u32 table_index, struct acpi_namespace_node *parent_node)
 
 acpi_status
 acpi_tb_install_and_load_table(acpi_physical_address address,
-			       u8 flags, u8 override, u32 *table_index)
+			       u8 flags,
+			       struct acpi_table_header *table,
+			       u8 override, u32 *table_index)
 {
 	acpi_status status;
 	u32 i;
@@ -979,7 +1012,7 @@ acpi_tb_install_and_load_table(acpi_physical_address address,
 
 	/* Install the table and load it into the namespace */
 
-	status = acpi_tb_install_standard_table(address, flags, TRUE,
+	status = acpi_tb_install_standard_table(address, flags, table, TRUE,
 						override, &i);
 	if (ACPI_FAILURE(status)) {
 		goto exit;

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);
 		}
 	}

drivers/acpi/acpica/tbinstal.c

@@ -79,6 +79,8 @@ acpi_tb_install_table_with_override(struct acpi_table_desc *new_table_desc,
  * PARAMETERS:  address             - Address of the table (might be a virtual
  *                                    address depending on the table_flags)
  *              flags               - Flags for the table
+ *              table               - Pointer to the table (required for virtual
+ *                                    origins, optional for physical)
  *              reload              - Whether reload should be performed
  *              override            - Whether override should be performed
  *              table_index         - Where the table index is returned
@@ -96,6 +98,7 @@ acpi_tb_install_table_with_override(struct acpi_table_desc *new_table_desc,
 acpi_status
 acpi_tb_install_standard_table(acpi_physical_address address,
 			       u8 flags,
+			       struct acpi_table_header *table,
 			       u8 reload, u8 override, u32 *table_index)
 {
 	u32 i;
@@ -106,7 +109,8 @@ acpi_tb_install_standard_table(acpi_physical_address address,
 
 	/* Acquire a temporary table descriptor for validation */
 
-	status = acpi_tb_acquire_temp_table(&new_table_desc, address, flags);
+	status =
+	    acpi_tb_acquire_temp_table(&new_table_desc, address, flags, table);
 	if (ACPI_FAILURE(status)) {
 		ACPI_ERROR((AE_INFO,
 			    "Could not acquire table length at %8.8X%8.8X",
@@ -209,7 +213,8 @@ void acpi_tb_override_table(struct acpi_table_desc *old_table_desc)
 	if (ACPI_SUCCESS(status) && table) {
 		acpi_tb_acquire_temp_table(&new_table_desc,
 					   ACPI_PTR_TO_PHYSADDR(table),
-					   ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL);
+					   ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL,
+					   table);
 		ACPI_ERROR_ONLY(override_type = "Logical");
 		goto finish_override;
 	}
@@ -220,7 +225,8 @@ void acpi_tb_override_table(struct acpi_table_desc *old_table_desc)
 						 &address, &length);
 	if (ACPI_SUCCESS(status) && address && length) {
 		acpi_tb_acquire_temp_table(&new_table_desc, address,
-					   ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL);
+					   ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
+					   NULL);
 		ACPI_ERROR_ONLY(override_type = "Physical");
 		goto finish_override;
 	}
@@ -289,7 +295,8 @@ void acpi_tb_uninstall_table(struct acpi_table_desc *table_desc)
 
 	if ((table_desc->flags & ACPI_TABLE_ORIGIN_MASK) ==
 	    ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL) {
-		ACPI_FREE(ACPI_PHYSADDR_TO_PTR(table_desc->address));
+		ACPI_FREE(table_desc->pointer);
+		table_desc->pointer = NULL;
 	}
 
 	table_desc->address = ACPI_PTR_TO_PHYSADDR(NULL);

drivers/acpi/acpica/tbutils.c

@@ -328,7 +328,7 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
 
 		status = acpi_tb_install_standard_table(address,
 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
-							FALSE, TRUE,
+							NULL, FALSE, TRUE,
 							&table_index);
 
 		if (ACPI_SUCCESS(status) &&

drivers/acpi/acpica/tbxfload.c

@@ -227,9 +227,7 @@ acpi_status acpi_tb_load_namespace(void)
  *
  * FUNCTION:    acpi_install_table
  *
- * PARAMETERS:  address             - Address of the ACPI table to be installed.
- *              physical            - Whether the address is a physical table
- *                                    address or not
+ * PARAMETERS:  table               - Pointer to the ACPI table to be installed.
  *
  * RETURN:      Status
  *
@@ -240,28 +238,54 @@ acpi_status acpi_tb_load_namespace(void)
  ******************************************************************************/
 
 acpi_status ACPI_INIT_FUNCTION
-acpi_install_table(acpi_physical_address address, u8 physical)
+acpi_install_table(struct acpi_table_header *table)
 {
 	acpi_status status;
-	u8 flags;
 	u32 table_index;
 
 	ACPI_FUNCTION_TRACE(acpi_install_table);
 
-	if (physical) {
-		flags = ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL;
-	} else {
-		flags = ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL;
-	}
-
-	status = acpi_tb_install_standard_table(address, flags,
-						FALSE, FALSE, &table_index);
+	status = acpi_tb_install_standard_table(ACPI_PTR_TO_PHYSADDR(table),
+						ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL,
+						table, FALSE, FALSE,
+						&table_index);
 
 	return_ACPI_STATUS(status);
 }
 
 ACPI_EXPORT_SYMBOL_INIT(acpi_install_table)
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_install_physical_table
+ *
+ * PARAMETERS:  address             - Address of the ACPI table to be installed.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Dynamically install an ACPI table.
+ *              Note: This function should only be invoked after
+ *                    acpi_initialize_tables() and before acpi_load_tables().
+ *
+ ******************************************************************************/
+acpi_status ACPI_INIT_FUNCTION
+acpi_install_physical_table(acpi_physical_address address)
+{
+	acpi_status status;
+	u32 table_index;
+
+	ACPI_FUNCTION_TRACE(acpi_install_physical_table);
+
+	status = acpi_tb_install_standard_table(address,
+						ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
+						NULL, FALSE, FALSE,
+						&table_index);
+
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL_INIT(acpi_install_physical_table)
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_load_table
@@ -298,7 +322,7 @@ acpi_status acpi_load_table(struct acpi_table_header *table, u32 *table_idx)
 	ACPI_INFO(("Host-directed Dynamic ACPI Table Load:"));
 	status = acpi_tb_install_and_load_table(ACPI_PTR_TO_PHYSADDR(table),
 						ACPI_TABLE_ORIGIN_EXTERNAL_VIRTUAL,
-						FALSE, &table_index);
+						table, FALSE, &table_index);
 	if (table_idx) {
 		*table_idx = table_index;
 	}