ARM: 7505/1: split out ATAGS parsing

Make ATAGS parsing into a source file of its own, namely atags_parse.c.
Also rename compat.c to atags_compat.c to make it clearer what it is
about.  Same for atags.c which is now atags_proc.c. Gather all the atags
function declarations into a common atags.h.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

7 files changed, 247 insertions, 251 deletions

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 7ad2d5cf7008..086c9d3bc360 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -15,11 +15,11 @@ CFLAGS_REMOVE_return_address.o = -pg
 
 # Object file lists.
 
-obj-y           := elf.o entry-armv.o entry-common.o irq.o opcodes.o \
+obj-y           := atags_parse.o elf.o entry-armv.o entry-common.o irq.o opcodes.o \
                    process.o ptrace.o return_address.o sched_clock.o \
                    setup.o signal.o stacktrace.o sys_arm.o time.o traps.o
 
-obj-$(CONFIG_DEPRECATED_PARAM_STRUCT) += compat.o
+obj-$(CONFIG_DEPRECATED_PARAM_STRUCT) += atags_compat.o
 
 obj-$(CONFIG_LEDS)              += leds.o
 obj-$(CONFIG_OC_ETM)            += etm.o
@@ -52,7 +52,7 @@ test-kprobes-objs		+= kprobes-test-thumb.o
 else
 test-kprobes-objs               += kprobes-test-arm.o
 endif
-obj-$(CONFIG_ATAGS_PROC)        += atags.o
+obj-$(CONFIG_ATAGS_PROC)        += atags_proc.o
 obj-$(CONFIG_OABI_COMPAT)       += sys_oabi-compat.o
 obj-$(CONFIG_ARM_THUMBEE)       += thumbee.o
 obj-$(CONFIG_KGDB)              += kgdb.o
diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
index e5f028d214a1..a888fdd381b5 100644
--- a/arch/arm/kernel/atags.h
+++ b/arch/arm/kernel/atags.h
@@ -3,3 +3,6 @@ extern void save_atags(struct tag *tags);
 #else
 static inline void save_atags(struct tag *tags) { }
 #endif
+
+void convert_to_tag_list(struct tag *tags);
+struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr);
diff --git a/arch/arm/kernel/compat.c b/arch/arm/kernel/atags_compat.c
index 925652318b8b..5236ad38f417 100644
--- a/arch/arm/kernel/compat.c
+++ b/arch/arm/kernel/atags_compat.c
@@ -1,5 +1,5 @@
 /*
- *  linux/arch/arm/kernel/compat.c
+ *  linux/arch/arm/kernel/atags_compat.c
  *
  *  Copyright (C) 2001 Russell King
  *
@@ -26,7 +26,7 @@
 
 #include <asm/mach/arch.h>
 
-#include "compat.h"
+#include "atags.h"
 
 /*
  * Usage:
diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c
new file mode 100644
index 000000000000..14512e6931d8
--- /dev/null
+++ b/arch/arm/kernel/atags_parse.c
@@ -0,0 +1,238 @@
+/*
+ * Tag parsing.
+ *
+ * Copyright (C) 1995-2001 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This is the traditional way of passing data to the kernel at boot time.  Rather
+ * than passing a fixed inflexible structure to the kernel, we pass a list
+ * of variable-sized tags to the kernel.  The first tag must be a ATAG_CORE
+ * tag for the list to be recognised (to distinguish the tagged list from
+ * a param_struct).  The list is terminated with a zero-length tag (this tag
+ * is not parsed in any way).
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/root_dev.h>
+#include <linux/screen_info.h>
+
+#include <asm/setup.h>
+#include <asm/system_info.h>
+#include <asm/page.h>
+#include <asm/mach/arch.h>
+
+#include "atags.h"
+
+static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE;
+
+#ifndef MEM_SIZE
+#define MEM_SIZE        (16*1024*1024)
+#endif
+
+static struct {
+        struct tag_header hdr1;
+        struct tag_core   core;
+        struct tag_header hdr2;
+        struct tag_mem32  mem;
+        struct tag_header hdr3;
+} default_tags __initdata = {
+        { tag_size(tag_core), ATAG_CORE },
+        { 1, PAGE_SIZE, 0xff },
+        { tag_size(tag_mem32), ATAG_MEM },
+        { MEM_SIZE },
+        { 0, ATAG_NONE }
+};
+
+static int __init parse_tag_core(const struct tag *tag)
+{
+        if (tag->hdr.size > 2) {
+                if ((tag->u.core.flags & 1) == 0)
+                        root_mountflags &= ~MS_RDONLY;
+                ROOT_DEV = old_decode_dev(tag->u.core.rootdev);
+        }
+        return 0;
+}
+
+__tagtable(ATAG_CORE, parse_tag_core);
+
+static int __init parse_tag_mem32(const struct tag *tag)
+{
+        return arm_add_memory(tag->u.mem.start, tag->u.mem.size);
+}
+
+__tagtable(ATAG_MEM, parse_tag_mem32);
+
+#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
+static int __init parse_tag_videotext(const struct tag *tag)
+{
+        screen_info.orig_x            = tag->u.videotext.x;
+        screen_info.orig_y            = tag->u.videotext.y;
+        screen_info.orig_video_page   = tag->u.videotext.video_page;
+        screen_info.orig_video_mode   = tag->u.videotext.video_mode;
+        screen_info.orig_video_cols   = tag->u.videotext.video_cols;
+        screen_info.orig_video_ega_bx = tag->u.videotext.video_ega_bx;
+        screen_info.orig_video_lines  = tag->u.videotext.video_lines;
+        screen_info.orig_video_isVGA  = tag->u.videotext.video_isvga;
+        screen_info.orig_video_points = tag->u.videotext.video_points;
+        return 0;
+}
+
+__tagtable(ATAG_VIDEOTEXT, parse_tag_videotext);
+#endif
+
+#ifdef CONFIG_BLK_DEV_RAM
+static int __init parse_tag_ramdisk(const struct tag *tag)
+{
+        extern int rd_size, rd_image_start, rd_prompt, rd_doload;
+
+        rd_image_start = tag->u.ramdisk.start;
+        rd_doload = (tag->u.ramdisk.flags & 1) == 0;
+        rd_prompt = (tag->u.ramdisk.flags & 2) == 0;
+
+        if (tag->u.ramdisk.size)
+                rd_size = tag->u.ramdisk.size;
+
+        return 0;
+}
+
+__tagtable(ATAG_RAMDISK, parse_tag_ramdisk);
+#endif
+
+static int __init parse_tag_serialnr(const struct tag *tag)
+{
+        system_serial_low = tag->u.serialnr.low;
+        system_serial_high = tag->u.serialnr.high;
+        return 0;
+}
+
+__tagtable(ATAG_SERIAL, parse_tag_serialnr);
+
+static int __init parse_tag_revision(const struct tag *tag)
+{
+        system_rev = tag->u.revision.rev;
+        return 0;
+}
+
+__tagtable(ATAG_REVISION, parse_tag_revision);
+
+static int __init parse_tag_cmdline(const struct tag *tag)
+{
+#if defined(CONFIG_CMDLINE_EXTEND)
+        strlcat(default_command_line, " ", COMMAND_LINE_SIZE);
+        strlcat(default_command_line, tag->u.cmdline.cmdline,
+                COMMAND_LINE_SIZE);
+#elif defined(CONFIG_CMDLINE_FORCE)
+        pr_warning("Ignoring tag cmdline (using the default kernel command line)\n");
+#else
+        strlcpy(default_command_line, tag->u.cmdline.cmdline,
+                COMMAND_LINE_SIZE);
+#endif
+        return 0;
+}
+
+__tagtable(ATAG_CMDLINE, parse_tag_cmdline);
+
+/*
+ * Scan the tag table for this tag, and call its parse function.
+ * The tag table is built by the linker from all the __tagtable
+ * declarations.
+ */
+static int __init parse_tag(const struct tag *tag)
+{
+        extern struct tagtable __tagtable_begin, __tagtable_end;
+        struct tagtable *t;
+
+        for (t = &__tagtable_begin; t < &__tagtable_end; t++)
+                if (tag->hdr.tag == t->tag) {
+                        t->parse(tag);
+                        break;
+                }
+
+        return t < &__tagtable_end;
+}
+
+/*
+ * Parse all tags in the list, checking both the global and architecture
+ * specific tag tables.
+ */
+static void __init parse_tags(const struct tag *t)
+{
+        for (; t->hdr.size; t = tag_next(t))
+                if (!parse_tag(t))
+                        printk(KERN_WARNING
+                                "Ignoring unrecognised tag 0x%08x\n",
+                                t->hdr.tag);
+}
+
+static void __init squash_mem_tags(struct tag *tag)
+{
+        for (; tag->hdr.size; tag = tag_next(tag))
+                if (tag->hdr.tag == ATAG_MEM)
+                        tag->hdr.tag = ATAG_NONE;
+}
+
+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;
+        char *from = default_command_line;
+
+        default_tags.mem.start = PHYS_OFFSET;
+
+        /*
+         * locate machine in the list of supported machines.
+         */
+        for_each_machine_desc(p)
+                if (machine_nr == p->nr) {
+                        printk("Machine: %s\n", p->name);
+                        mdesc = p;
+                        break;
+                }
+
+        if (!mdesc) {
+                early_print("\nError: unrecognized/unsupported machine ID"
+                            " (r1 = 0x%08x).\n\n", machine_nr);
+                dump_machine_table(); /* does not return */
+        }
+
+        if (__atags_pointer)
+                tags = phys_to_virt(__atags_pointer);
+        else if (mdesc->atag_offset)
+                tags = (void *)(PAGE_OFFSET + mdesc->atag_offset);
+
+#if defined(CONFIG_DEPRECATED_PARAM_STRUCT)
+        /*
+         * If we have the old style parameters, convert them to
+         * a tag list.
+         */
+        if (tags->hdr.tag != ATAG_CORE)
+                convert_to_tag_list(tags);
+#endif
+        if (tags->hdr.tag != ATAG_CORE) {
+                early_print("Warning: Neither atags nor dtb found\n");
+                tags = (struct tag *)&default_tags;
+        }
+
+        if (mdesc->fixup)
+                mdesc->fixup(tags, &from, &meminfo);
+
+        if (tags->hdr.tag == ATAG_CORE) {
+                if (meminfo.nr_banks != 0)
+                        squash_mem_tags(tags);
+                save_atags(tags);
+                parse_tags(tags);
+        }
+
+        /* parse_early_param needs a boot_command_line */
+        strlcpy(boot_command_line, from, COMMAND_LINE_SIZE);
+
+        return mdesc;
+}
diff --git a/arch/arm/kernel/atags.c b/arch/arm/kernel/atags_proc.c
index 42a1a1415fa6..42a1a1415fa6 100644
--- a/arch/arm/kernel/atags.c
+++ b/arch/arm/kernel/atags_proc.c
diff --git a/arch/arm/kernel/compat.h b/arch/arm/kernel/compat.h
deleted file mode 100644
index 39264ab1b9c6..000000000000
--- a/arch/arm/kernel/compat.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/*
- *  linux/arch/arm/kernel/compat.h
- *
- *  Copyright (C) 2001 Russell King
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
-*/
-
-extern void convert_to_tag_list(struct tag *tags);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index a81dcecc7343..0785472460a8 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -21,11 +21,9 @@
 #include <linux/init.h>
 #include <linux/kexec.h>
 #include <linux/of_fdt.h>
-#include <linux/root_dev.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/smp.h>
-#include <linux/fs.h>
 #include <linux/proc_fs.h>
 #include <linux/memblock.h>
 #include <linux/bug.h>
@@ -56,15 +54,9 @@
 #include <asm/unwind.h>
 #include <asm/memblock.h>
 
-#if defined(CONFIG_DEPRECATED_PARAM_STRUCT)
-#include "compat.h"
-#endif
 #include "atags.h"
 #include "tcm.h"
 
-#ifndef MEM_SIZE
-#define MEM_SIZE        (16*1024*1024)
-#endif
 
 #if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
 char fpe_type[8];
@@ -145,7 +137,6 @@ static const char *machine_name;
 static char __initdata cmd_line[COMMAND_LINE_SIZE];
 struct machine_desc *machine_desc __initdata;
 
-static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE;
 static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
 #define ENDIANNESS ((char)endian_test.l)
 
@@ -583,21 +574,6 @@ static int __init early_mem(char *p)
 }
 early_param("mem", early_mem);
 
-static void __init
-setup_ramdisk(int doload, int prompt, int image_start, unsigned int rd_sz)
-{
-#ifdef CONFIG_BLK_DEV_RAM
-        extern int rd_size, rd_image_start, rd_prompt, rd_doload;
-
-        rd_image_start = image_start;
-        rd_prompt = prompt;
-        rd_doload = doload;
-
-        if (rd_sz)
-                rd_size = rd_sz;
-#endif
-}
-
 static void __init request_standard_resources(struct machine_desc *mdesc)
 {
         struct memblock_region *region;
@@ -643,35 +619,6 @@ static void __init request_standard_resources(struct machine_desc *mdesc)
                 request_resource(&ioport_resource, &lp2);
 }
 
-/*
- *  Tag parsing.
- *
- * This is the new way of passing data to the kernel at boot time.  Rather
- * than passing a fixed inflexible structure to the kernel, we pass a list
- * of variable-sized tags to the kernel.  The first tag must be a ATAG_CORE
- * tag for the list to be recognised (to distinguish the tagged list from
- * a param_struct).  The list is terminated with a zero-length tag (this tag
- * is not parsed in any way).
- */
-static int __init parse_tag_core(const struct tag *tag)
-{
-        if (tag->hdr.size > 2) {
-                if ((tag->u.core.flags & 1) == 0)
-                        root_mountflags &= ~MS_RDONLY;
-                ROOT_DEV = old_decode_dev(tag->u.core.rootdev);
-        }
-        return 0;
-}
-
-__tagtable(ATAG_CORE, parse_tag_core);
-
-static int __init parse_tag_mem32(const struct tag *tag)
-{
-        return arm_add_memory(tag->u.mem.start, tag->u.mem.size);
-}
-
-__tagtable(ATAG_MEM, parse_tag_mem32);
-
 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
 struct screen_info screen_info = {
  .orig_video_lines      = 30,
@@ -681,117 +628,8 @@ struct screen_info screen_info = {
  .orig_video_isVGA      = 1,
  .orig_video_points     = 8
 };
-
-static int __init parse_tag_videotext(const struct tag *tag)
-{
-        screen_info.orig_x            = tag->u.videotext.x;
-        screen_info.orig_y            = tag->u.videotext.y;
-        screen_info.orig_video_page   = tag->u.videotext.video_page;
-        screen_info.orig_video_mode   = tag->u.videotext.video_mode;
-        screen_info.orig_video_cols   = tag->u.videotext.video_cols;
-        screen_info.orig_video_ega_bx = tag->u.videotext.video_ega_bx;
-        screen_info.orig_video_lines  = tag->u.videotext.video_lines;
-        screen_info.orig_video_isVGA  = tag->u.videotext.video_isvga;
-        screen_info.orig_video_points = tag->u.videotext.video_points;
-        return 0;
-}
-
-__tagtable(ATAG_VIDEOTEXT, parse_tag_videotext);
 #endif
 
-static int __init parse_tag_ramdisk(const struct tag *tag)
-{
-        setup_ramdisk((tag->u.ramdisk.flags & 1) == 0,
-                      (tag->u.ramdisk.flags & 2) == 0,
-                      tag->u.ramdisk.start, tag->u.ramdisk.size);
-        return 0;
-}
-
-__tagtable(ATAG_RAMDISK, parse_tag_ramdisk);
-
-static int __init parse_tag_serialnr(const struct tag *tag)
-{
-        system_serial_low = tag->u.serialnr.low;
-        system_serial_high = tag->u.serialnr.high;
-        return 0;
-}
-
-__tagtable(ATAG_SERIAL, parse_tag_serialnr);
-
-static int __init parse_tag_revision(const struct tag *tag)
-{
-        system_rev = tag->u.revision.rev;
-        return 0;
-}
-
-__tagtable(ATAG_REVISION, parse_tag_revision);
-
-static int __init parse_tag_cmdline(const struct tag *tag)
-{
-#if defined(CONFIG_CMDLINE_EXTEND)
-        strlcat(default_command_line, " ", COMMAND_LINE_SIZE);
-        strlcat(default_command_line, tag->u.cmdline.cmdline,
-                COMMAND_LINE_SIZE);
-#elif defined(CONFIG_CMDLINE_FORCE)
-        pr_warning("Ignoring tag cmdline (using the default kernel command line)\n");
-#else
-        strlcpy(default_command_line, tag->u.cmdline.cmdline,
-                COMMAND_LINE_SIZE);
-#endif
-        return 0;
-}
-
-__tagtable(ATAG_CMDLINE, parse_tag_cmdline);
-
-/*
- * Scan the tag table for this tag, and call its parse function.
- * The tag table is built by the linker from all the __tagtable
- * declarations.
- */
-static int __init parse_tag(const struct tag *tag)
-{
-        extern struct tagtable __tagtable_begin, __tagtable_end;
-        struct tagtable *t;
-
-        for (t = &__tagtable_begin; t < &__tagtable_end; t++)
-                if (tag->hdr.tag == t->tag) {
-                        t->parse(tag);
-                        break;
-                }
-
-        return t < &__tagtable_end;
-}
-
-/*
- * Parse all tags in the list, checking both the global and architecture
- * specific tag tables.
- */
-static void __init parse_tags(const struct tag *t)
-{
-        for (; t->hdr.size; t = tag_next(t))
-                if (!parse_tag(t))
-                        printk(KERN_WARNING
-                                "Ignoring unrecognised tag 0x%08x\n",
-                                t->hdr.tag);
-}
-
-/*
- * This holds our defaults.
- */
-static struct init_tags {
-        struct tag_header hdr1;
-        struct tag_core   core;
-        struct tag_header hdr2;
-        struct tag_mem32  mem;
-        struct tag_header hdr3;
-} init_tags __initdata = {
-        { tag_size(tag_core), ATAG_CORE },
-        { 1, PAGE_SIZE, 0xff },
-        { tag_size(tag_mem32), ATAG_MEM },
-        { MEM_SIZE },
-        { 0, ATAG_NONE }
-};
-
 static int __init customize_machine(void)
 {
         /* customizes platform devices, or adds new ones */
@@ -858,78 +696,6 @@ static void __init reserve_crashkernel(void)
 static inline void reserve_crashkernel(void) {}
 #endif /* CONFIG_KEXEC */
 
-static void __init squash_mem_tags(struct tag *tag)
-{
-        for (; tag->hdr.size; tag = tag_next(tag))
-                if (tag->hdr.tag == ATAG_MEM)
-                        tag->hdr.tag = ATAG_NONE;
-}
-
-static struct machine_desc * __init setup_machine_tags(unsigned int nr)
-{
-        struct tag *tags = (struct tag *)&init_tags;
-        struct machine_desc *mdesc = NULL, *p;
-        char *from = default_command_line;
-
-        init_tags.mem.start = PHYS_OFFSET;
-
-        /*
-         * locate machine in the list of supported machines.
-         */
-        for_each_machine_desc(p)
-                if (nr == p->nr) {
-                        printk("Machine: %s\n", p->name);
-                        mdesc = p;
-                        break;
-                }
-
-        if (!mdesc) {
-                early_print("\nError: unrecognized/unsupported machine ID"
-                        " (r1 = 0x%08x).\n\n", nr);
-                dump_machine_table(); /* does not return */
-        }
-
-        if (__atags_pointer)
-                tags = phys_to_virt(__atags_pointer);
-        else if (mdesc->atag_offset)
-                tags = (void *)(PAGE_OFFSET + mdesc->atag_offset);
-
-#if defined(CONFIG_DEPRECATED_PARAM_STRUCT)
-        /*
-         * If we have the old style parameters, convert them to
-         * a tag list.
-         */
-        if (tags->hdr.tag != ATAG_CORE)
-                convert_to_tag_list(tags);
-#endif
-
-        if (tags->hdr.tag != ATAG_CORE) {
-#if defined(CONFIG_OF)
-                /*
-                 * If CONFIG_OF is set, then assume this is a reasonably
-                 * modern system that should pass boot parameters
-                 */
-                early_print("Warning: Neither atags nor dtb found\n");
-#endif
-                tags = (struct tag *)&init_tags;
-        }
-
-        if (mdesc->fixup)
-                mdesc->fixup(tags, &from, &meminfo);
-
-        if (tags->hdr.tag == ATAG_CORE) {
-                if (meminfo.nr_banks != 0)
-                        squash_mem_tags(tags);
-                save_atags(tags);
-                parse_tags(tags);
-        }
-
-        /* parse_early_param needs a boot_command_line */
-        strlcpy(boot_command_line, from, COMMAND_LINE_SIZE);
-
-        return mdesc;
-}
-
 static int __init meminfo_cmp(const void *_a, const void *_b)
 {
         const struct membank *a = _a, *b = _b;
@@ -944,7 +710,7 @@ void __init setup_arch(char **cmdline_p)
         setup_processor();
         mdesc = setup_machine_fdt(__atags_pointer);
         if (!mdesc)
-                mdesc = setup_machine_tags(machine_arch_type);
+                mdesc = setup_machine_tags(__atags_pointer, machine_arch_type);
         machine_desc = mdesc;
         machine_name = mdesc->name;