powerpc: make ARCH=ppc use arch/powerpc/kernel/process.c

Commit 5388fb1025 made signal_32.c
use discard_lazy_cpu_state, which broke ARCH=ppc because that
uses the common signal_32.c but has its own process.c.  Make ARCH=ppc
use the common process.c to fix this and to reduce the amount
of duplicated code.

Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/Makefile

@@ -11,7 +11,8 @@ CFLAGS_btext.o		+= -fPIC
 endif
 
 obj-y				:= semaphore.o cputable.o ptrace.o syscalls.o \
-				   irq.o align.o signal_32.o pmc.o vdso.o
+				   irq.o align.o signal_32.o pmc.o vdso.o \
+				   init_task.o process.o
 obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)		+= setup_64.o binfmt_elf32.o sys_ppc32.o \
 				   signal_64.o ptrace32.o systbl.o \
@@ -44,8 +45,7 @@ extra-$(CONFIG_FSL_BOOKE)	:= head_fsl_booke.o
 extra-$(CONFIG_8xx)		:= head_8xx.o
 extra-y				+= vmlinux.lds
 
-obj-y				+= process.o init_task.o time.o \
-				   prom.o traps.o setup-common.o udbg.o
+obj-y				+= time.o prom.o traps.o setup-common.o udbg.o
 obj-$(CONFIG_PPC32)		+= entry_32.o setup_32.o misc_32.o systbl.o
 obj-$(CONFIG_PPC64)		+= misc_64.o dma_64.o iommu.o
 obj-$(CONFIG_PPC_MULTIPLATFORM)	+= prom_init.o

arch/powerpc/kernel/process.c

@@ -223,6 +223,7 @@ void discard_lazy_cpu_state(void)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_PPC_MERGE		/* XXX for now */
 int set_dabr(unsigned long dabr)
 {
 	if (ppc_md.set_dabr)
@@ -231,6 +232,7 @@ int set_dabr(unsigned long dabr)
 	mtspr(SPRN_DABR, dabr);
 	return 0;
 }
+#endif
 
 #ifdef CONFIG_PPC64
 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);

arch/ppc/kernel/Makefile

@@ -13,7 +13,6 @@ extra-$(CONFIG_POWER4)		+= idle_power4.o
 extra-y				+= vmlinux.lds
 
 obj-y				:= entry.o traps.o idle.o time.o misc.o \
-					process.o \
 					setup.o \
 					ppc_htab.o
 obj-$(CONFIG_6xx)		+= l2cr.o cpu_setup_6xx.o

include/asm-ppc/system.h

@@ -4,7 +4,6 @@
 #ifndef __PPC_SYSTEM_H
 #define __PPC_SYSTEM_H
 
-#include <linux/config.h>
 #include <linux/kernel.h>
 
 #include <asm/atomic.h>
@@ -39,7 +38,7 @@
 #ifdef CONFIG_SMP
 #define smp_mb()	mb()
 #define smp_rmb()	rmb()
-#define smp_wmb()	wmb()
+#define smp_wmb()	__asm__ __volatile__ ("eieio" : : : "memory")
 #define smp_read_barrier_depends()	read_barrier_depends()
 #else
 #define smp_mb()	barrier()
@@ -74,6 +73,7 @@ extern void chrp_nvram_init(void);
 extern void read_rtc_time(void);
 extern void pmac_find_display(void);
 extern void giveup_fpu(struct task_struct *);
+extern void disable_kernel_fp(void);
 extern void enable_kernel_fp(void);
 extern void flush_fp_to_thread(struct task_struct *);
 extern void enable_kernel_altivec(void);
@@ -86,6 +86,14 @@ extern int fix_alignment(struct pt_regs *);
 extern void cvt_fd(float *from, double *to, struct thread_struct *thread);
 extern void cvt_df(double *from, float *to, struct thread_struct *thread);
 
+#ifndef CONFIG_SMP
+extern void discard_lazy_cpu_state(void);
+#else
+static inline void discard_lazy_cpu_state(void)
+{
+}
+#endif
+
 #ifdef CONFIG_ALTIVEC
 extern void flush_altivec_to_thread(struct task_struct *);
 #else