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/arch/powerpc/mm/pgtable64.c b/arch/powerpc/mm/pgtable64.c
new file mode 100644
index 0000000..724f97e
--- /dev/null
+++ b/arch/powerpc/mm/pgtable64.c
@@ -0,0 +1,357 @@
+/*
+ *  This file contains ioremap and related functions for 64-bit machines.
+ *
+ *  Derived from arch/ppc64/mm/init.c
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
+ *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Paul Mackerras
+ *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ *  Dave Engebretsen <engebret@us.ibm.com>
+ *      Rework for PPC64 port.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/idr.h>
+#include <linux/nodemask.h>
+#include <linux/module.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/prom.h>
+#include <asm/lmb.h>
+#include <asm/rtas.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/uaccess.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/tlb.h>
+#include <asm/eeh.h>
+#include <asm/processor.h>
+#include <asm/mmzone.h>
+#include <asm/cputable.h>
+#include <asm/ppcdebug.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/iommu.h>
+#include <asm/abs_addr.h>
+#include <asm/vdso.h>
+#include <asm/imalloc.h>
+
+#if PGTABLE_RANGE > USER_VSID_RANGE
+#warning Limited user VSID range means pagetable space is wasted
+#endif
+
+#if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
+#warning TASK_SIZE is smaller than it needs to be.
+#endif
+
+int mem_init_done;
+unsigned long ioremap_bot = IMALLOC_BASE;
+static unsigned long phbs_io_bot = PHBS_IO_BASE;
+
+extern pgd_t swapper_pg_dir[];
+extern struct task_struct *current_set[NR_CPUS];
+
+unsigned long klimit = (unsigned long)_end;
+
+/* max amount of RAM to use */
+unsigned long __max_memory;
+
+/* info on what we think the IO hole is */
+unsigned long 	io_hole_start;
+unsigned long	io_hole_size;
+
+#ifdef CONFIG_PPC_ISERIES
+
+void __iomem *ioremap(unsigned long addr, unsigned long size)
+{
+	return (void __iomem *)addr;
+}
+
+extern void __iomem *__ioremap(unsigned long addr, unsigned long size,
+		       unsigned long flags)
+{
+	return (void __iomem *)addr;
+}
+
+void iounmap(volatile void __iomem *addr)
+{
+	return;
+}
+
+#else
+
+/*
+ * map_io_page currently only called by __ioremap
+ * map_io_page adds an entry to the ioremap page table
+ * and adds an entry to the HPT, possibly bolting it
+ */
+static int map_io_page(unsigned long ea, unsigned long pa, int flags)
+{
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+	unsigned long vsid;
+
+	if (mem_init_done) {
+		spin_lock(&init_mm.page_table_lock);
+		pgdp = pgd_offset_k(ea);
+		pudp = pud_alloc(&init_mm, pgdp, ea);
+		if (!pudp)
+			return -ENOMEM;
+		pmdp = pmd_alloc(&init_mm, pudp, ea);
+		if (!pmdp)
+			return -ENOMEM;
+		ptep = pte_alloc_kernel(&init_mm, pmdp, ea);
+		if (!ptep)
+			return -ENOMEM;
+		set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
+							  __pgprot(flags)));
+		spin_unlock(&init_mm.page_table_lock);
+	} else {
+		unsigned long va, vpn, hash, hpteg;
+
+		/*
+		 * If the mm subsystem is not fully up, we cannot create a
+		 * linux page table entry for this mapping.  Simply bolt an
+		 * entry in the hardware page table.
+		 */
+		vsid = get_kernel_vsid(ea);
+		va = (vsid << 28) | (ea & 0xFFFFFFF);
+		vpn = va >> PAGE_SHIFT;
+
+		hash = hpt_hash(vpn, 0);
+
+		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
+
+		/* Panic if a pte grpup is full */
+		if (ppc_md.hpte_insert(hpteg, va, pa >> PAGE_SHIFT,
+				       HPTE_V_BOLTED,
+				       _PAGE_NO_CACHE|_PAGE_GUARDED|PP_RWXX)
+		    == -1) {
+			panic("map_io_page: could not insert mapping");
+		}
+	}
+	return 0;
+}
+
+
+static void __iomem * __ioremap_com(unsigned long addr, unsigned long pa,
+			    unsigned long ea, unsigned long size,
+			    unsigned long flags)
+{
+	unsigned long i;
+
+	if ((flags & _PAGE_PRESENT) == 0)
+		flags |= pgprot_val(PAGE_KERNEL);
+
+	for (i = 0; i < size; i += PAGE_SIZE)
+		if (map_io_page(ea+i, pa+i, flags))
+			return NULL;
+
+	return (void __iomem *) (ea + (addr & ~PAGE_MASK));
+}
+
+
+void __iomem *
+ioremap(unsigned long addr, unsigned long size)
+{
+	return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
+}
+
+void __iomem * __ioremap(unsigned long addr, unsigned long size,
+			 unsigned long flags)
+{
+	unsigned long pa, ea;
+	void __iomem *ret;
+
+	/*
+	 * Choose an address to map it to.
+	 * Once the imalloc system is running, we use it.
+	 * Before that, we map using addresses going
+	 * up from ioremap_bot.  imalloc will use
+	 * the addresses from ioremap_bot through
+	 * IMALLOC_END
+	 * 
+	 */
+	pa = addr & PAGE_MASK;
+	size = PAGE_ALIGN(addr + size) - pa;
+
+	if (size == 0)
+		return NULL;
+
+	if (mem_init_done) {
+		struct vm_struct *area;
+		area = im_get_free_area(size);
+		if (area == NULL)
+			return NULL;
+		ea = (unsigned long)(area->addr);
+		ret = __ioremap_com(addr, pa, ea, size, flags);
+		if (!ret)
+			im_free(area->addr);
+	} else {
+		ea = ioremap_bot;
+		ret = __ioremap_com(addr, pa, ea, size, flags);
+		if (ret)
+			ioremap_bot += size;
+	}
+	return ret;
+}
+
+#define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
+
+int __ioremap_explicit(unsigned long pa, unsigned long ea,
+		       unsigned long size, unsigned long flags)
+{
+	struct vm_struct *area;
+	void __iomem *ret;
+	
+	/* For now, require page-aligned values for pa, ea, and size */
+	if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
+	    !IS_PAGE_ALIGNED(size)) {
+		printk(KERN_ERR	"unaligned value in %s\n", __FUNCTION__);
+		return 1;
+	}
+	
+	if (!mem_init_done) {
+		/* Two things to consider in this case:
+		 * 1) No records will be kept (imalloc, etc) that the region
+		 *    has been remapped
+		 * 2) It won't be easy to iounmap() the region later (because
+		 *    of 1)
+		 */
+		;
+	} else {
+		area = im_get_area(ea, size,
+			IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
+		if (area == NULL) {
+			/* Expected when PHB-dlpar is in play */
+			return 1;
+		}
+		if (ea != (unsigned long) area->addr) {
+			printk(KERN_ERR "unexpected addr return from "
+			       "im_get_area\n");
+			return 1;
+		}
+	}
+	
+	ret = __ioremap_com(pa, pa, ea, size, flags);
+	if (ret == NULL) {
+		printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
+		return 1;
+	}
+	if (ret != (void *) ea) {
+		printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+/*  
+ * Unmap an IO region and remove it from imalloc'd list.
+ * Access to IO memory should be serialized by driver.
+ * This code is modeled after vmalloc code - unmap_vm_area()
+ *
+ * XXX	what about calls before mem_init_done (ie python_countermeasures())
+ */
+void iounmap(volatile void __iomem *token)
+{
+	void *addr;
+
+	if (!mem_init_done)
+		return;
+	
+	addr = (void *) ((unsigned long __force) token & PAGE_MASK);
+
+	im_free(addr);
+}
+
+static int iounmap_subset_regions(unsigned long addr, unsigned long size)
+{
+	struct vm_struct *area;
+
+	/* Check whether subsets of this region exist */
+	area = im_get_area(addr, size, IM_REGION_SUPERSET);
+	if (area == NULL)
+		return 1;
+
+	while (area) {
+		iounmap((void __iomem *) area->addr);
+		area = im_get_area(addr, size,
+				IM_REGION_SUPERSET);
+	}
+
+	return 0;
+}
+
+int iounmap_explicit(volatile void __iomem *start, unsigned long size)
+{
+	struct vm_struct *area;
+	unsigned long addr;
+	int rc;
+	
+	addr = (unsigned long __force) start & PAGE_MASK;
+
+	/* Verify that the region either exists or is a subset of an existing
+	 * region.  In the latter case, split the parent region to create 
+	 * the exact region 
+	 */
+	area = im_get_area(addr, size, 
+			    IM_REGION_EXISTS | IM_REGION_SUBSET);
+	if (area == NULL) {
+		/* Determine whether subset regions exist.  If so, unmap */
+		rc = iounmap_subset_regions(addr, size);
+		if (rc) {
+			printk(KERN_ERR
+			       "%s() cannot unmap nonexistent range 0x%lx\n",
+ 				__FUNCTION__, addr);
+			return 1;
+		}
+	} else {
+		iounmap((void __iomem *) area->addr);
+	}
+	/*
+	 * FIXME! This can't be right:
+	iounmap(area->addr);
+	 * Maybe it should be "iounmap(area);"
+	 */
+	return 0;
+}
+
+#endif
+
+EXPORT_SYMBOL(ioremap);
+EXPORT_SYMBOL(__ioremap);
+EXPORT_SYMBOL(iounmap);