tile: normalize global variables exported by vmlinux.lds

Normalize global variables exported by vmlinux.lds to conform usage
guidelines from include/asm-generic/sections.h.

1) Use _text to mark the start of the kernel image including the head
text, and _stext to mark the start of the .text section.
2) Export mandatory global variables __init_begin and __init_end.

Signed-off-by: Jiang Liu <[e-mail]>
Acked-by: Chris Metcalf <[e-mail]>
Cc: Rusty Russell <[e-mail]>
Cc: Bjorn Helgaas <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Wen Congyang <[e-mail]>
Cc: David Howells <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/tile/include/asm/sections.h

···
 extern char __start_atomic_asm_code[], __end_atomic_asm_code[];
 #endif
 
-/* Handle the discontiguity between _sdata and _stext. */
+/* Handle the discontiguity between _sdata and _text. */
 static inline int arch_is_kernel_data(unsigned long addr)
 {
 	return addr >= (unsigned long)_sdata &&

arch/tile/kernel/setup.c

···
 		hv_store_mapping(addr, pages << PAGE_SHIFT, pa);
 	}
 
-	hv_store_mapping((HV_VirtAddr)_stext,
-			 (uint32_t)(_einittext - _stext), 0);
+	hv_store_mapping((HV_VirtAddr)_text,
+			 (uint32_t)(_einittext - _text), 0);
 }
 
 /*

arch/tile/kernel/vmlinux.lds.S

···
   .intrpt1 (LOAD_OFFSET) : AT ( 0 )   /* put at the start of physical memory */
   {
     _text = .;
-    _stext = .;
     *(.intrpt1)
   } :intrpt1 =0
 
···
 
   /* Now the real code */
   . = ALIGN(0x20000);
+  _stext = .;
   .text : AT (ADDR(.text) - LOAD_OFFSET) {
     HEAD_TEXT
     SCHED_TEXT
···
   #define LOAD_OFFSET PAGE_OFFSET
 
   . = ALIGN(PAGE_SIZE);
+  __init_begin = .;
   VMLINUX_SYMBOL(_sinitdata) = .;
   INIT_DATA_SECTION(16) :data =0
   PERCPU_SECTION(L2_CACHE_BYTES)
   . = ALIGN(PAGE_SIZE);
   VMLINUX_SYMBOL(_einitdata) = .;
+  __init_end = .;
 
   _sdata = .;                   /* Start of data section */
 

arch/tile/mm/init.c

···
 			prot = ktext_set_nocache(prot);
 		}
 
-		BUG_ON(address != (unsigned long)_stext);
+		BUG_ON(address != (unsigned long)_text);
 		pte = NULL;
 		for (; address < (unsigned long)_einittext;
 		     pfn++, address += PAGE_SIZE) {