[PATCH] xen/ACPI: Remove the acpi_string type

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Typedef-ing a naked pointer like this an anti-pattern which is best avoided.
Furthermore, it's bad to pass a string literate in a mutable type.  Delete the
type entirely, and replace it with a plain 'const char *'.

This highlights two futher bugs.  acpi_get_table() already had a mismatch in
types between it's declaration and definition, and we have declarations for
acpi_get_handle() and acpi_get_table_header() but no definition at all (nor
any callers).

This fixes violations of MISRA Rule 7.4:

  A string literal shall not be assigned to an object unless the object's type
  is "pointer to const-qualified char".

and of Rule 8.3:

  All declarations of an object or function shall use the same names and type
  qualifiers.

and of Rule 8.6:

  An identifier with external linkage shall have exactly one external
  definition.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Roberto Bagnara <roberto.bagnara@xxxxxxxxxxx>
CC: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>

Roberto/Nicola: Please double check my choice of rules here, and point out any
others that I may have missed.
---
 xen/drivers/acpi/tables/tbxface.c |  4 ++--
 xen/include/acpi/acpixf.h         | 13 ++-----------
 xen/include/acpi/actypes.h        |  1 -
 3 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/xen/drivers/acpi/tables/tbxface.c 
b/xen/drivers/acpi/tables/tbxface.c
index 21b2e5eae1c7..204d66caea48 100644
--- a/xen/drivers/acpi/tables/tbxface.c
+++ b/xen/drivers/acpi/tables/tbxface.c
@@ -164,7 +164,7 @@ acpi_initialize_tables(struct acpi_table_desc * 
initial_table_array,
  *
  *****************************************************************************/
 acpi_status __init
-acpi_get_table(char *signature,
+acpi_get_table(const char *signature,
               acpi_native_uint instance, struct acpi_table_header **out_table)
 {
        acpi_native_uint i;
@@ -220,7 +220,7 @@ acpi_get_table(char *signature,
  *
  *****************************************************************************/
 acpi_status __init
-acpi_get_table_phys(acpi_string signature, acpi_native_uint instance,
+acpi_get_table_phys(const char *signature, acpi_native_uint instance,
                     acpi_physical_address *addr, acpi_native_uint *len)
 {
        acpi_native_uint i, j;
diff --git a/xen/include/acpi/acpixf.h b/xen/include/acpi/acpixf.h
index ba74908f0478..8b70154b8f96 100644
--- a/xen/include/acpi/acpixf.h
+++ b/xen/include/acpi/acpixf.h
@@ -69,25 +69,16 @@ acpi_status acpi_load_tables(void);
 acpi_status acpi_load_table(struct acpi_table_header *table_ptr);
 
 acpi_status
-acpi_get_table_header(acpi_string signature,
-                     acpi_native_uint instance,
-                     struct acpi_table_header *out_table_header);
-
-acpi_status
-acpi_get_table(acpi_string signature,
+acpi_get_table(const char *signature,
               acpi_native_uint instance, struct acpi_table_header **out_table);
 
 acpi_status
-acpi_get_table_phys(acpi_string signature, acpi_native_uint instance,
+acpi_get_table_phys(const char *signature, acpi_native_uint instance,
                     acpi_physical_address *addr, acpi_native_uint *len);
 /*
  * Namespace and name interfaces
  */
 acpi_status
-acpi_get_handle(acpi_handle parent,
-               acpi_string pathname, acpi_handle * ret_handle);
-
-acpi_status
 acpi_debug_trace(char *name, u32 debug_level, u32 debug_layer, u32 flags);
 
 acpi_status
diff --git a/xen/include/acpi/actypes.h b/xen/include/acpi/actypes.h
index f3e95abc3ab3..7023863d0349 100644
--- a/xen/include/acpi/actypes.h
+++ b/xen/include/acpi/actypes.h
@@ -281,7 +281,6 @@ typedef acpi_native_uint acpi_size;
  */
 typedef u32 acpi_status;       /* All ACPI Exceptions */
 typedef u32 acpi_name;         /* 4-byte ACPI name */
-typedef char *acpi_string;     /* Null terminated ASCII string */
 typedef void *acpi_handle;     /* Actually a ptr to a NS Node */
 
 struct uint64_struct {
-- 
2.30.2