ARM: constify machine_desc structure uses

struct machine_desc records are defined everywhere as a 'const'
structure, but unfortuantely it loses its const-ness through the use of
linker magic - the symbols which surround the section are not declared
const so it becomes possible not to use 'const' for pointers to these
const structures.

Let's fix this oversight - all pointers to these structures should be
marked const too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 15 insertions, 14 deletions

diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
index 9edc969..ec4164d 100644
--- a/arch/arm/kernel/atags.h
+++ b/arch/arm/kernel/atags.h
@@ -7,9 +7,10 @@ static inline void save_atags(struct tag *tags) { }
 void convert_to_tag_list(struct tag *tags);
 
 #ifdef CONFIG_ATAGS
-struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr);
+const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
+	unsigned int machine_nr);
 #else
-static inline struct machine_desc *
+static inline const struct machine_desc *
 setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
 {
 	early_print("no ATAGS support: can't continue\n");
diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c
index 14512e6..8c14de8 100644
--- a/arch/arm/kernel/atags_parse.c
+++ b/arch/arm/kernel/atags_parse.c
@@ -178,11 +178,11 @@ static void __init squash_mem_tags(struct tag *tag)
 			tag->hdr.tag = ATAG_NONE;
 }
 
-struct machine_desc * __init setup_machine_tags(phys_addr_t __atags_pointer,
-						unsigned int machine_nr)
+const struct machine_desc * __init
+setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
 {
 	struct tag *tags = (struct tag *)&default_tags;
-	struct machine_desc *mdesc = NULL, *p;
+	const struct machine_desc *mdesc = NULL, *p;
 	char *from = default_command_line;
 
 	default_tags.mem.start = PHYS_OFFSET;
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 5859c8b..eae1976 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -176,10 +176,10 @@ void __init arm_dt_init_cpu_maps(void)
  * If a dtb was passed to the kernel in r2, then use it to choose the
  * correct machine_desc and to setup the system.
  */
-struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
+const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
 {
 	struct boot_param_header *devtree;
-	struct machine_desc *mdesc, *mdesc_best = NULL;
+	const struct machine_desc *mdesc, *mdesc_best = NULL;
 	unsigned int score, mdesc_score = ~1;
 	unsigned long dt_root;
 	const char *model;
@@ -188,7 +188,7 @@ struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
 	DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
 	MACHINE_END
 
-	mdesc_best = (struct machine_desc *)&__mach_desc_GENERIC_DT;
+	mdesc_best = &__mach_desc_GENERIC_DT;
 #endif
 
 	if (!dt_phys)
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 63af9a7..8636299 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -72,10 +72,10 @@ static int __init fpe_setup(char *line)
 __setup("fpe=", fpe_setup);
 #endif
 
-extern void paging_init(struct machine_desc *desc);
+extern void paging_init(const struct machine_desc *desc);
 extern void sanity_check_meminfo(void);
 extern enum reboot_mode reboot_mode;
-extern void setup_dma_zone(struct machine_desc *desc);
+extern void setup_dma_zone(const struct machine_desc *desc);
 
 unsigned int processor_id;
 EXPORT_SYMBOL(processor_id);
@@ -139,7 +139,7 @@ EXPORT_SYMBOL(elf_platform);
 static const char *cpu_name;
 static const char *machine_name;
 static char __initdata cmd_line[COMMAND_LINE_SIZE];
-struct machine_desc *machine_desc __initdata;
+const struct machine_desc *machine_desc __initdata;
 
 static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
 #define ENDIANNESS ((char)endian_test.l)
@@ -607,7 +607,7 @@ static void __init setup_processor(void)
 
 void __init dump_machine_table(void)
 {
-	struct machine_desc *p;
+	const struct machine_desc *p;
 
 	early_print("Available machine support:\n\nID (hex)\tNAME\n");
 	for_each_machine_desc(p)
@@ -694,7 +694,7 @@ static int __init early_mem(char *p)
 }
 early_param("mem", early_mem);
 
-static void __init request_standard_resources(struct machine_desc *mdesc)
+static void __init request_standard_resources(const struct machine_desc *mdesc)
 {
 	struct memblock_region *region;
 	struct resource *res;
@@ -850,7 +850,7 @@ void __init hyp_mode_check(void)
 
 void __init setup_arch(char **cmdline_p)
 {
-	struct machine_desc *mdesc;
+	const struct machine_desc *mdesc;
 
 	setup_processor();
 	mdesc = setup_machine_fdt(__atags_pointer);