libata-acpi: adjust constness in ata_acpi_gtm/stm() parameters

* No internal function uses const ata_port.  Drop const from @ap.

* Make ata_acpi_stm() copy @stm before using it and change @stm to
  const.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 6 insertions, 5 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 545ea865ceb5..8ae36ad029c5 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -200,7 +200,7 @@ void ata_acpi_associate(struct ata_host *host)
  * RETURNS:
  * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
  */
-int ata_acpi_gtm(const struct ata_port *ap, struct ata_acpi_gtm *gtm)
+int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)
 {
         struct acpi_buffer output = { .length = ACPI_ALLOCATE_BUFFER };
         union acpi_object *out_obj;
@@ -259,15 +259,16 @@ EXPORT_SYMBOL_GPL(ata_acpi_gtm);
  * RETURNS:
  * 0 on success, -ENOENT if _STM doesn't exist, -errno on failure.
  */
-int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm)
+int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm)
 {
         acpi_status status;
+        struct ata_acpi_gtm             stm_buf = *stm;
         struct acpi_object_list         input;
         union acpi_object               in_params[3];
 
         in_params[0].type = ACPI_TYPE_BUFFER;
         in_params[0].buffer.length = sizeof(struct ata_acpi_gtm);
-        in_params[0].buffer.pointer = (u8 *)stm;
+        in_params[0].buffer.pointer = (u8 *)&stm_buf;
         /* Buffers for id may need byteswapping ? */
         in_params[1].type = ACPI_TYPE_BUFFER;
         in_params[1].buffer.length = 512;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index ef52a07c43d8..1ca9b89632f9 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -940,8 +940,8 @@ enum {
 /* libata-acpi.c */
 #ifdef CONFIG_ATA_ACPI
 extern int ata_acpi_cbl_80wire(struct ata_port *ap);
-int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm);
-int ata_acpi_gtm(const struct ata_port *ap, struct ata_acpi_gtm *stm);
+int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm);
+int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *stm);
 #else
 static inline int ata_acpi_cbl_80wire(struct ata_port *ap) { return 0; }
 #endif