powerpc: Merge enough to start building in arch/powerpc.

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
new file mode 100644
index 0000000..be542ef
--- /dev/null
+++ b/include/asm-powerpc/system.h
@@ -0,0 +1,350 @@
+/*
+ * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
+ */
+#ifndef __PPC_SYSTEM_H
+#define __PPC_SYSTEM_H
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+
+#include <asm/hw_irq.h>
+#include <asm/ppc_asm.h>
+
+/*
+ * Memory barrier.
+ * The sync instruction guarantees that all memory accesses initiated
+ * by this processor have been performed (with respect to all other
+ * mechanisms that access memory).  The eieio instruction is a barrier
+ * providing an ordering (separately) for (a) cacheable stores and (b)
+ * loads and stores to non-cacheable memory (e.g. I/O devices).
+ *
+ * mb() prevents loads and stores being reordered across this point.
+ * rmb() prevents loads being reordered across this point.
+ * wmb() prevents stores being reordered across this point.
+ * read_barrier_depends() prevents data-dependent loads being reordered
+ *	across this point (nop on PPC).
+ *
+ * We have to use the sync instructions for mb(), since lwsync doesn't
+ * order loads with respect to previous stores.  Lwsync is fine for
+ * rmb(), though.  Note that lwsync is interpreted as sync by
+ * 32-bit and older 64-bit CPUs.
+ *
+ * For wmb(), we use sync since wmb is used in drivers to order
+ * stores to system memory with respect to writes to the device.
+ * However, smp_wmb() can be a lighter-weight eieio barrier on
+ * SMP since it is only used to order updates to system memory.
+ */
+#define mb()   __asm__ __volatile__ ("sync" : : : "memory")
+#define rmb()  __asm__ __volatile__ ("lwsync" : : : "memory")
+#define wmb()  __asm__ __volatile__ ("sync" : : : "memory")
+#define read_barrier_depends()  do { } while(0)
+
+#define set_mb(var, value)	do { var = value; mb(); } while (0)
+#define set_wmb(var, value)	do { var = value; wmb(); } while (0)
+
+#ifdef CONFIG_SMP
+#define smp_mb()	mb()
+#define smp_rmb()	rmb()
+#define smp_wmb()	__asm__ __volatile__ ("eieio" : : : "memory")
+#define smp_read_barrier_depends()	read_barrier_depends()
+#else
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#define smp_read_barrier_depends()	do { } while(0)
+#endif /* CONFIG_SMP */
+
+#ifdef __KERNEL__
+struct task_struct;
+struct pt_regs;
+
+#ifdef CONFIG_DEBUGGER
+
+extern int (*__debugger)(struct pt_regs *regs);
+extern int (*__debugger_ipi)(struct pt_regs *regs);
+extern int (*__debugger_bpt)(struct pt_regs *regs);
+extern int (*__debugger_sstep)(struct pt_regs *regs);
+extern int (*__debugger_iabr_match)(struct pt_regs *regs);
+extern int (*__debugger_dabr_match)(struct pt_regs *regs);
+extern int (*__debugger_fault_handler)(struct pt_regs *regs);
+
+#define DEBUGGER_BOILERPLATE(__NAME) \
+static inline int __NAME(struct pt_regs *regs) \
+{ \
+	if (unlikely(__ ## __NAME)) \
+		return __ ## __NAME(regs); \
+	return 0; \
+}
+
+DEBUGGER_BOILERPLATE(debugger)
+DEBUGGER_BOILERPLATE(debugger_ipi)
+DEBUGGER_BOILERPLATE(debugger_bpt)
+DEBUGGER_BOILERPLATE(debugger_sstep)
+DEBUGGER_BOILERPLATE(debugger_iabr_match)
+DEBUGGER_BOILERPLATE(debugger_dabr_match)
+DEBUGGER_BOILERPLATE(debugger_fault_handler)
+
+#ifdef CONFIG_XMON
+extern void xmon_init(int enable);
+#endif
+
+#else
+static inline int debugger(struct pt_regs *regs) { return 0; }
+static inline int debugger_ipi(struct pt_regs *regs) { return 0; }
+static inline int debugger_bpt(struct pt_regs *regs) { return 0; }
+static inline int debugger_sstep(struct pt_regs *regs) { return 0; }
+static inline int debugger_iabr_match(struct pt_regs *regs) { return 0; }
+static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; }
+static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
+#endif
+
+extern int set_dabr(unsigned long dabr);
+extern void print_backtrace(unsigned long *);
+extern void show_regs(struct pt_regs * regs);
+extern void flush_instruction_cache(void);
+extern void hard_reset_now(void);
+extern void poweroff_now(void);
+
+#ifdef CONFIG_6xx
+extern long _get_L2CR(void);
+extern long _get_L3CR(void);
+extern void _set_L2CR(unsigned long);
+extern void _set_L3CR(unsigned long);
+#else
+#define _get_L2CR()	0L
+#define _get_L3CR()	0L
+#define _set_L2CR(val)	do { } while(0)
+#define _set_L3CR(val)	do { } while(0)
+#endif
+
+extern void via_cuda_init(void);
+extern void pmac_nvram_init(void);
+extern void read_rtc_time(void);
+extern void pmac_find_display(void);
+extern void giveup_fpu(struct task_struct *);
+extern void enable_kernel_fp(void);
+extern void flush_fp_to_thread(struct task_struct *);
+extern void enable_kernel_altivec(void);
+extern void giveup_altivec(struct task_struct *);
+extern void load_up_altivec(struct task_struct *);
+extern void giveup_spe(struct task_struct *);
+extern void load_up_spe(struct task_struct *);
+extern int fix_alignment(struct pt_regs *);
+extern void cvt_fd(float *from, double *to, unsigned long *fpscr);
+extern void cvt_df(double *from, float *to, unsigned long *fpscr);
+
+#ifdef CONFIG_ALTIVEC
+extern void flush_altivec_to_thread(struct task_struct *);
+#else
+static inline void flush_altivec_to_thread(struct task_struct *t)
+{
+}
+#endif
+
+#ifdef CONFIG_SPE
+extern void flush_spe_to_thread(struct task_struct *);
+#else
+static inline void flush_spe_to_thread(struct task_struct *t)
+{
+}
+#endif
+
+extern int call_rtas(const char *, int, int, unsigned long *, ...);
+extern void cacheable_memzero(void *p, unsigned int nb);
+extern void *cacheable_memcpy(void *, const void *, unsigned int);
+extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
+extern void bad_page_fault(struct pt_regs *, unsigned long, int);
+extern int die(const char *, struct pt_regs *, long);
+extern void _exception(int, struct pt_regs *, int, unsigned long);
+#ifdef CONFIG_BOOKE_WDT
+extern u32 booke_wdt_enabled;
+extern u32 booke_wdt_period;
+#endif /* CONFIG_BOOKE_WDT */
+
+/* EBCDIC -> ASCII conversion for [0-9A-Z] on iSeries */
+extern unsigned char e2a(unsigned char);
+
+struct device_node;
+extern void note_scsi_host(struct device_node *, void *);
+
+extern struct task_struct *__switch_to(struct task_struct *,
+	struct task_struct *);
+#define switch_to(prev, next, last)	((last) = __switch_to((prev), (next)))
+
+struct thread_struct;
+extern struct task_struct *_switch(struct thread_struct *prev,
+				   struct thread_struct *next);
+
+extern unsigned int rtas_data;
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __inline__ unsigned long
+__xchg_u32(volatile void *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+	EIEIO_ON_SMP
+"1:	lwarx	%0,0,%2 \n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%3,0,%2 \n\
+	bne-	1b"
+	ISYNC_ON_SMP
+	: "=&r" (prev), "=m" (*(volatile unsigned int *)p)
+	: "r" (p), "r" (val), "m" (*(volatile unsigned int *)p)
+	: "cc", "memory");
+
+	return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __inline__ unsigned long
+__xchg_u64(volatile void *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+	EIEIO_ON_SMP
+"1:	ldarx	%0,0,%2 \n"
+	PPC405_ERR77(0,%2)
+"	stdcx.	%3,0,%2 \n\
+	bne-	1b"
+	ISYNC_ON_SMP
+	: "=&r" (prev), "=m" (*(volatile unsigned long *)p)
+	: "r" (p), "r" (val), "m" (*(volatile unsigned long *)p)
+	: "cc", "memory");
+
+	return prev;
+}
+#endif
+
+/*
+ * This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid xchg().
+ */
+extern void __xchg_called_with_bad_pointer(void);
+
+static __inline__ unsigned long
+__xchg(volatile void *ptr, unsigned long x, unsigned int size)
+{
+	switch (size) {
+	case 4:
+		return __xchg_u32(ptr, x);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __xchg_u64(ptr, x);
+#endif
+	}
+	__xchg_called_with_bad_pointer();
+	return x;
+}
+
+#define xchg(ptr,x)							     \
+  ({									     \
+     __typeof__(*(ptr)) _x_ = (x);					     \
+     (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
+  })
+
+#define tas(ptr) (xchg((ptr),1))
+
+/*
+ * Compare and exchange - if *p == old, set it to new,
+ * and return the old value of *p.
+ */
+#define __HAVE_ARCH_CMPXCHG	1
+
+static __inline__ unsigned long
+__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
+{
+	unsigned int prev;
+
+	__asm__ __volatile__ (
+	EIEIO_ON_SMP
+"1:	lwarx	%0,0,%2		# __cmpxchg_u32\n\
+	cmpw	0,%0,%3\n\
+	bne-	2f\n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%4,0,%2\n\
+	bne-	1b"
+	ISYNC_ON_SMP
+	"\n\
+2:"
+	: "=&r" (prev), "=m" (*p)
+	: "r" (p), "r" (old), "r" (new), "m" (*p)
+	: "cc", "memory");
+
+	return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __inline__ unsigned long
+__cmpxchg_u64(volatile long *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+	EIEIO_ON_SMP
+"1:	ldarx	%0,0,%2		# __cmpxchg_u64\n\
+	cmpd	0,%0,%3\n\
+	bne-	2f\n\
+	stdcx.	%4,0,%2\n\
+	bne-	1b"
+	ISYNC_ON_SMP
+	"\n\
+2:"
+	: "=&r" (prev), "=m" (*p)
+	: "r" (p), "r" (old), "r" (new), "m" (*p)
+	: "cc", "memory");
+
+	return prev;
+}
+#endif
+
+/* This function doesn't exist, so you'll get a linker error
+   if something tries to do an invalid cmpxchg().  */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+static __inline__ unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
+	  unsigned int size)
+{
+	switch (size) {
+	case 4:
+		return __cmpxchg_u32(ptr, old, new);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __cmpxchg_u64(ptr, old, new);
+#endif
+	}
+	__cmpxchg_called_with_bad_pointer();
+	return old;
+}
+
+#define cmpxchg(ptr,o,n)						 \
+  ({									 \
+     __typeof__(*(ptr)) _o_ = (o);					 \
+     __typeof__(*(ptr)) _n_ = (n);					 \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
+				    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
+
+#ifdef CONFIG_PPC64
+/*
+ * We handle most unaligned accesses in hardware. On the other hand 
+ * unaligned DMA can be very expensive on some ppc64 IO chips (it does
+ * powers of 2 writes until it reaches sufficient alignment).
+ *
+ * Based on this we disable the IP header alignment in network drivers.
+ */
+#define NET_IP_ALIGN   0
+#endif
+
+#define arch_align_stack(x) (x)
+
+#endif /* __KERNEL__ */
+#endif /* __PPC_SYSTEM_H */