m68k: print memory layout info in boot log

Output a table of the kernel memory regions at boot time.
This is taken directly from the ARM architecture code that does this.
The table looks like this:

Virtual kernel memory layout:
vector : 0x00000000 - 0x00000400 ( 0 KiB)
kmap : 0xd0000000 - 0xe0000000 ( 256 MiB)
vmalloc : 0xc0000000 - 0xcfffffff ( 255 MiB)
lowmem : 0x00000000 - 0x02000000 ( 32 MiB)
.init : 0x00128000 - 0x00134000 ( 48 KiB)
.text : 0x00020000 - 0x00118d54 ( 996 KiB)
.data : 0x00118d60 - 0x00126000 ( 53 KiB)
.bss : 0x00134000 - 0x001413e0 ( 53 KiB)

This has been very useful while debugging the ColdFire virtual memory
support code. But in general I think it is nice to know extacly where
the kernel has layed everything out on boot.

Signed-off-by: Greg Ungerer <[e-mail]>

arch/m68k/include/asm/traps.h

···
 
 typedef void (*e_vector)(void);
 extern e_vector vectors[];
+extern e_vector *_ramvec;
 
 asmlinkage void auto_inthandler(void);
 asmlinkage void user_inthandler(void);

arch/m68k/kernel/vmlinux-std.lds

···
 
   RW_DATA_SECTION(16, PAGE_SIZE, THREAD_SIZE)
 
+  _sbss = .;
   BSS_SECTION(0, 0, 0)
+  _ebss = .;
 
   _edata = .;			/* End of data section */
 

arch/m68k/kernel/vmlinux-sun3.lds

···
 	. = ALIGN(PAGE_SIZE);
 	__init_end = .;
 
+  _sbss = .;
   BSS_SECTION(0, 0, 0)
+  _ebss = .;
 
   _end = . ;
 

arch/m68k/mm/init_mm.c

···
 #include <asm/page.h>
 #include <asm/pgalloc.h>
 #include <asm/system.h>
+#include <asm/traps.h>
 #include <asm/machdep.h>
 #include <asm/io.h>
 #ifdef CONFIG_ATARI
···
 
 extern pmd_t *zero_pgtable;
 
+#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
+#define VECTORS	&vectors[0]
+#else
+#define VECTORS	_ramvec
+#endif
+
+void __init print_memmap(void)
+{
+#define UL(x) ((unsigned long) (x))
+#define MLK(b, t) UL(b), UL(t), (UL(t) - UL(b)) >> 10
+#define MLM(b, t) UL(b), UL(t), (UL(t) - UL(b)) >> 20
+#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), 1024)
+
+	pr_notice("Virtual kernel memory layout:\n"
+		"    vector  : 0x%08lx - 0x%08lx   (%4ld KiB)\n"
+		"    kmap    : 0x%08lx - 0x%08lx   (%4ld MiB)\n"
+		"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MiB)\n"
+		"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MiB)\n"
+		"      .init : 0x%p" " - 0x%p" "   (%4d KiB)\n"
+		"      .text : 0x%p" " - 0x%p" "   (%4d KiB)\n"
+		"      .data : 0x%p" " - 0x%p" "   (%4d KiB)\n"
+		"      .bss  : 0x%p" " - 0x%p" "   (%4d KiB)\n",
+		MLK(VECTORS, VECTORS + 256),
+		MLM(KMAP_START, KMAP_END),
+		MLM(VMALLOC_START, VMALLOC_END),
+		MLM(PAGE_OFFSET, (unsigned long)high_memory),
+		MLK_ROUNDUP(__init_begin, __init_end),
+		MLK_ROUNDUP(_stext, _etext),
+		MLK_ROUNDUP(_sdata, _edata),
+		MLK_ROUNDUP(_sbss, _ebss));
+}
+
 void __init mem_init(void)
 {
 	pg_data_t *pgdat;
···
 	       codepages << (PAGE_SHIFT-10),
 	       datapages << (PAGE_SHIFT-10),
 	       initpages << (PAGE_SHIFT-10));
+	print_memmap();
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD