tile: Use generic init_task

Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/20120503085035.528129988@linutronix.de

arch/tile/Kconfig

@@ -13,6 +13,7 @@ config TILE
 	select GENERIC_IRQ_SHOW
 	select SYS_HYPERVISOR
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select HAVE_GENERIC_INIT_TASK
 
 # FIXME: investigate whether we need/want these options.
 #	select HAVE_IOREMAP_PROT

arch/tile/kernel/Makefile

@@ -3,7 +3,7 @@
 #
 
 extra-y := vmlinux.lds head_$(BITS).o
-obj-y := backtrace.o entry.o init_task.o irq.o messaging.o \
+obj-y := backtrace.o entry.o irq.o messaging.o \
 	pci-dma.o proc.o process.o ptrace.o reboot.o \
 	setup.o signal.o single_step.o stack.o sys.o sysfs.o time.o traps.o \
 	intvec_$(BITS).o regs_$(BITS).o tile-desc_$(BITS).o

arch/tile/kernel/setup.c

@@ -61,6 +61,22 @@ unsigned long __initdata node_free_pfn[MAX_NUMNODES];
 
 static unsigned long __initdata node_percpu[MAX_NUMNODES];
 
+/*
+ * per-CPU stack and boot info.
+ */
+DEFINE_PER_CPU(unsigned long, boot_sp) =
+	(unsigned long)init_stack + THREAD_SIZE;
+
+#ifdef CONFIG_SMP
+DEFINE_PER_CPU(unsigned long, boot_pc) = (unsigned long)start_kernel;
+#else
+/*
+ * The variable must be __initdata since it references __init code.
+ * With CONFIG_SMP it is per-cpu data, which is exempt from validation.
+ */
+unsigned long __initdata boot_pc = (unsigned long)start_kernel;
+#endif
+
 #ifdef CONFIG_HIGHMEM
 /* Page frame index of end of lowmem on each controller. */
 unsigned long __cpuinitdata node_lowmem_end_pfn[MAX_NUMNODES];