sparc32: get rid of fake_swapper_regs

no reason to have ->kregs of initial thread set up in a special
way - we can keep them on stack, same as for every other thread.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/sparc/include/asm/processor_32.h

@@ -60,6 +60,7 @@ struct thread_struct {
 #define INIT_THREAD  { \
 	.flags = SPARC_FLAG_KTHREAD, \
 	.current_ds = KERNEL_DS, \
+	.kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
 }
 
 /* Do necessary setup to start up a newly executed thread. */

arch/sparc/kernel/head_32.S

@@ -515,7 +515,7 @@ continue_boot:
 
 		/* I want a kernel stack NOW! */
 		set	init_thread_union, %g1
-		set	(THREAD_SIZE - STACKFRAME_SZ), %g2
+		set	(THREAD_SIZE - STACKFRAME_SZ - TRACEREG_SZ), %g2
 		add	%g1, %g2, %sp
 		mov	0, %fp			/* And for good luck */
 

arch/sparc/kernel/process_32.c

@@ -218,14 +218,7 @@ void flush_thread(void)
 	}
 
 	/* This task is no longer a kernel thread. */
-	if (current->thread.flags & SPARC_FLAG_KTHREAD) {
 	current->thread.flags &= ~SPARC_FLAG_KTHREAD;
-
-		/* We must fixup kregs as well. */
-		/* XXX This was not fixed for ti for a while, worked. Unused? */
-		current->thread.kregs = (struct pt_regs *)
-		    (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
-	}
 }
 
 static inline struct sparc_stackf __user *

arch/sparc/kernel/setup_32.c

@@ -266,7 +266,6 @@ static __init void leon_patch(void)
 }
 
 struct tt_entry *sparc_ttable;
-static struct pt_regs fake_swapper_regs;
 
 /* Called from head_32.S - before we have setup anything
  * in the kernel. Be very careful with what you do here.
@@ -363,8 +362,6 @@ void __init setup_arch(char **cmdline_p)
 		(*(linux_dbvec->teach_debugger))();
 	}
 
-	init_task.thread.kregs = &fake_swapper_regs;
-
 	/* Run-time patch instructions to match the cpu model */
 	per_cpu_patch();