firewire: qualify config ROM cache pointers as const pointers

Several config ROM related functions only peek at the ROM cache; mark
their arguments as const pointers.  Ditto fw_device.config_rom and
fw_unit.directory, as the memory behind them is meant to be write-once.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

3 files changed, 20 insertions, 18 deletions

diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 5d5c6a689837..eecd52dc8e98 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -43,7 +43,7 @@
 
 #include "core.h"
 
-void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
+void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
 {
         ci->p = p + 1;
         ci->end = ci->p + (p[0] >> 16);
@@ -59,7 +59,7 @@ int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
 }
 EXPORT_SYMBOL(fw_csr_iterator_next);
 
-static u32 *search_leaf(u32 *directory, int search_key)
+static const u32 *search_leaf(const u32 *directory, int search_key)
 {
         struct fw_csr_iterator ci;
         int last_key = 0, key, value;
@@ -76,7 +76,7 @@ static u32 *search_leaf(u32 *directory, int search_key)
         return NULL;
 }
 
-static int textual_leaf_to_string(u32 *block, char *buf, size_t size)
+static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
 {
         unsigned int quadlets, i;
         char c;
@@ -116,9 +116,9 @@ static int textual_leaf_to_string(u32 *block, char *buf, size_t size)
  * the immediate entry with @key.  The string is zero-terminated.
  * Returns strlen(buf) or a negative error code.
  */
-int fw_csr_string(u32 *directory, int key, char *buf, size_t size)
+int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 {
-        u32 *leaf = search_leaf(directory, key);
+        const u32 *leaf = search_leaf(directory, key);
         if (!leaf)
                 return -ENOENT;
 
@@ -128,7 +128,7 @@ EXPORT_SYMBOL(fw_csr_string);
 
 static bool is_fw_unit(struct device *dev);
 
-static int match_unit_directory(u32 *directory, u32 match_flags,
+static int match_unit_directory(const u32 *directory, u32 match_flags,
                                 const struct ieee1394_device_id *id)
 {
         struct fw_csr_iterator ci;
@@ -262,7 +262,7 @@ static ssize_t show_immediate(struct device *dev,
         struct config_rom_attribute *attr =
                 container_of(dattr, struct config_rom_attribute, attr);
         struct fw_csr_iterator ci;
-        u32 *dir;
+        const u32 *dir;
         int key, value, ret = -ENOENT;
 
         down_read(&fw_device_rwsem);
@@ -293,7 +293,7 @@ static ssize_t show_text_leaf(struct device *dev,
 {
         struct config_rom_attribute *attr =
                 container_of(dattr, struct config_rom_attribute, attr);
-        u32 *dir;
+        const u32 *dir;
         size_t bufsize;
         char dummy_buf[2];
         int ret;
@@ -421,7 +421,7 @@ static ssize_t guid_show(struct device *dev,
         return ret;
 }
 
-static int units_sprintf(char *buf, u32 *directory)
+static int units_sprintf(char *buf, const u32 *directory)
 {
         struct fw_csr_iterator ci;
         int key, value;
@@ -503,7 +503,8 @@ static int read_rom(struct fw_device *device,
  */
 static int read_bus_info_block(struct fw_device *device, int generation)
 {
-        u32 *rom, *stack, *old_rom, *new_rom;
+        const u32 *old_rom, *new_rom;
+        u32 *rom, *stack;
         u32 sp, key;
         int i, end, length, ret = -1;
 
diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index d485cdd8cbac..7e33b0b1704c 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -1014,7 +1014,8 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
         return 0;
 }
 
-static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
+static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
+                                      const u32 *directory)
 {
         struct fw_csr_iterator ci;
         int key, value;
@@ -1027,7 +1028,7 @@ static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
         return 0;
 }
 
-static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
+static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
                               u32 *model, u32 *firmware_revision)
 {
         struct fw_csr_iterator ci;
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index df680216e7b6..4bd94bf5e739 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -65,13 +65,13 @@
 #define CSR_DIRECTORY_ID        0x20
 
 struct fw_csr_iterator {
-        u32 *p;
-        u32 *end;
+        const u32 *p;
+        const u32 *end;
 };
 
-void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 *p);
+void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p);
 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value);
-int fw_csr_string(u32 *directory, int key, char *buf, size_t size);
+int fw_csr_string(const u32 *directory, int key, char *buf, size_t size);
 
 extern struct bus_type fw_bus_type;
 
@@ -163,7 +163,7 @@ struct fw_device {
         struct mutex client_list_mutex;
         struct list_head client_list;
 
-        u32 *config_rom;
+        const u32 *config_rom;
         size_t config_rom_length;
         int config_rom_retries;
         unsigned is_local:1;
@@ -205,7 +205,7 @@ int fw_device_enable_phys_dma(struct fw_device *device);
  */
 struct fw_unit {
         struct device device;
-        u32 *directory;
+        const u32 *directory;
         struct fw_attribute_group attribute_group;
 };