init_64.c

/*
 *  arch/sparc64/mm/init.c
 *
 *  Copyright (C) 1996-1999 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1997-1999 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */
 
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <linux/poison.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/kprobes.h>
#include <linux/cache.h>
#include <linux/sort.h>
#include <linux/percpu.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/gfp.h>

#include <asm/head.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/oplib.h>
#include <asm/iommu.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/starfire.h>
#include <asm/tlb.h>
#include <asm/spitfire.h>
#include <asm/sections.h>
#include <asm/tsb.h>
#include <asm/hypervisor.h>
#include <asm/prom.h>
#include <asm/mdesc.h>
#include <asm/cpudata.h>
#include <asm/irq.h>

#include "init_64.h"

unsigned long kern_linear_pte_xor[4] __read_mostly;

/* A bitmap, two bits for every 256MB of physical memory.  These two
 * bits determine what page size we use for kernel linear
 * translations.  They form an index into kern_linear_pte_xor[].  The
 * value in the indexed slot is XOR'd with the TLB miss virtual
 * address to form the resulting TTE.  The mapping is:
 *
 *	0	==>	4MB
 *	1	==>	256MB
 *	2	==>	2GB
 *	3	==>	16GB
 *
 * All sun4v chips support 256MB pages.  Only SPARC-T4 and later
 * support 2GB pages, and hopefully future cpus will support the 16GB
 * pages as well.  For slots 2 and 3, we encode a 256MB TTE xor there
 * if these larger page sizes are not supported by the cpu.
 *
 * It would be nice to determine this from the machine description
 * 'cpu' properties, but we need to have this table setup before the
 * MDESC is initialized.
 */
unsigned long kpte_linear_bitmap[KPTE_BITMAP_BYTES / sizeof(unsigned long)];

#ifndef CONFIG_DEBUG_PAGEALLOC
/* A special kernel TSB for 4MB, 256MB, 2GB and 16GB linear mappings.
 * Space is allocated for this right after the trap table in
 * arch/sparc64/kernel/head.S
 */
extern struct tsb swapper_4m_tsb[KERNEL_TSB4M_NENTRIES];
#endif

static unsigned long cpu_pgsz_mask;

#define MAX_BANKS	32

static struct linux_prom64_registers pavail[MAX_BANKS];
static int pavail_ents;

static int cmp_p64(const void *a, const void *b)
{
	const struct linux_prom64_registers *x = a, *y = b;

	if (x->phys_addr > y->phys_addr)
		return 1;
	if (x->phys_addr < y->phys_addr)
		return -1;
	return 0;
}

static void __init read_obp_memory(const char *property,
				   struct linux_prom64_registers *regs,
				   int *num_ents)
{
	phandle node = prom_finddevice("/memory");
	int prop_size = prom_getproplen(node, property);
	int ents, ret, i;

	ents = prop_size / sizeof(struct linux_prom64_registers);
	if (ents > MAX_BANKS) {
		prom_printf("The machine has more %s property entries than "
			    "this kernel can support (%d).\n",
			    property, MAX_BANKS);
		prom_halt();
	}

	ret = prom_getproperty(node, property, (char *) regs, prop_size);
	if (ret == -1) {
		prom_printf("Couldn't get %s property from /memory.\n",
				property);
		prom_halt();
	}

	/* Sanitize what we got from the firmware, by page aligning
	 * everything.
	 */
	for (i = 0; i < ents; i++) {
		unsigned long base, size;

		base = regs[i].phys_addr;
		size = regs[i].reg_size;

		size &= PAGE_MASK;
		if (base & ~PAGE_MASK) {
			unsigned long new_base = PAGE_ALIGN(base);

			size -= new_base - base;
			if ((long) size < 0L)
				size = 0UL;
			base = new_base;
		}
		if (size == 0UL) {
			/* If it is empty, simply get rid of it.
			 * This simplifies the logic of the other
			 * functions that process these arrays.
			 */
			memmove(&regs[i], &regs[i + 1],
				(ents - i - 1) * sizeof(regs[0]));
			i--;
			ents--;
			continue;
		}
		regs[i].phys_addr = base;
		regs[i].reg_size = size;
	}

	*num_ents = ents;

	sort(regs, ents, sizeof(struct linux_prom64_registers),
	     cmp_p64, NULL);
}

unsigned long sparc64_valid_addr_bitmap[VALID_ADDR_BITMAP_BYTES /
					sizeof(unsigned long)];
EXPORT_SYMBOL(sparc64_valid_addr_bitmap);

/* Kernel physical address base and size in bytes.  */
unsigned long kern_base __read_mostly;
unsigned long kern_size __read_mostly;

/* Initial ramdisk setup */
extern unsigned long sparc_ramdisk_image64;
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;

struct page *mem_map_zero __read_mostly;
EXPORT_SYMBOL(mem_map_zero);

unsigned int sparc64_highest_unlocked_tlb_ent __read_mostly;

unsigned long sparc64_kern_pri_context __read_mostly;
unsigned long sparc64_kern_pri_nuc_bits __read_mostly;
unsigned long sparc64_kern_sec_context __read_mostly;

int num_kernel_image_mappings;

#ifdef CONFIG_DEBUG_DCFLUSH
atomic_t dcpage_flushes = ATOMIC_INIT(0);
#ifdef CONFIG_SMP
atomic_t dcpage_flushes_xcall = ATOMIC_INIT(0);
#endif
#endif

inline void flush_dcache_page_impl(struct page *page)
{
	BUG_ON(tlb_type == hypervisor);
#ifdef CONFIG_DEBUG_DCFLUSH
	atomic_inc(&dcpage_flushes);
#endif

#ifdef DCACHE_ALIASING_POSSIBLE
	__flush_dcache_page(page_address(page),
			    ((tlb_type == spitfire) &&
			     page_mapping(page) != NULL));
#else
	if (page_mapping(page) != NULL &&
	    tlb_type == spitfire)
		__flush_icache_page(__pa(page_address(page)));
#endif
}

#define PG_dcache_dirty		PG_arch_1
#define PG_dcache_cpu_shift	32UL
#define PG_dcache_cpu_mask	\
	((1UL<<ilog2(roundup_pow_of_two(NR_CPUS)))-1UL)

#define dcache_dirty_cpu(page) \
	(((page)->flags >> PG_dcache_cpu_shift) & PG_dcache_cpu_mask)

static inline void set_dcache_dirty(struct page *page, int this_cpu)
{
	unsigned long mask = this_cpu;
	unsigned long non_cpu_bits;

	non_cpu_bits = ~(PG_dcache_cpu_mask << PG_dcache_cpu_shift);
	mask = (mask << PG_dcache_cpu_shift) | (1UL << PG_dcache_dirty);

	__asm__ __volatile__("1:\n\t"
			     "ldx	[%2], %%g7\n\t"
			     "and	%%g7, %1, %%g1\n\t"
			     "or	%%g1, %0, %%g1\n\t"
			     "casx	[%2], %%g7, %%g1\n\t"
			     "cmp	%%g7, %%g1\n\t"
			     "bne,pn	%%xcc, 1b\n\t"
			     " nop"
			     : /* no outputs */
			     : "r" (mask), "r" (non_cpu_bits), "r" (&page->flags)
			     : "g1", "g7");
}

static inline void clear_dcache_dirty_cpu(struct page *page, unsigned long cpu)
{
	unsigned long mask = (1UL << PG_dcache_dirty);

	__asm__ __volatile__("! test_and_clear_dcache_dirty\n"
			     "1:\n\t"
			     "ldx	[%2], %%g7\n\t"
			     "srlx	%%g7, %4, %%g1\n\t"
			     "and	%%g1, %3, %%g1\n\t"
			     "cmp	%%g1, %0\n\t"
			     "bne,pn	%%icc, 2f\n\t"
			     " andn	%%g7, %1, %%g1\n\t"
			     "casx	[%2], %%g7, %%g1\n\t"
			     "cmp	%%g7, %%g1\n\t"
			     "bne,pn	%%xcc, 1b\n\t"
			     " nop\n"
			     "2:"
			     : /* no outputs */
			     : "r" (cpu), "r" (mask), "r" (&page->flags),
			       "i" (PG_dcache_cpu_mask),
			       "i" (PG_dcache_cpu_shift)
			     : "g1", "g7");
}

static inline void tsb_insert(struct tsb *ent, unsigned long tag, unsigned long pte)
{
	unsigned long tsb_addr = (unsigned long) ent;

	if (tlb_type == cheetah_plus || tlb_type == hypervisor)
		tsb_addr = __pa(tsb_addr);

	__tsb_insert(tsb_addr, tag, pte);
}

unsigned long _PAGE_ALL_SZ_BITS __read_mostly;

static void flush_dcache(unsigned long pfn)
{
	struct page *page;

	page = pfn_to_page(pfn);
	if (page) {
		unsigned long pg_flags;

		pg_flags = page->flags;
		if (pg_flags & (1UL << PG_dcache_dirty)) {
			int cpu = ((pg_flags >> PG_dcache_cpu_shift) &
				   PG_dcache_cpu_mask);
			int this_cpu = get_cpu();

			/* This is just to optimize away some function calls
			 * in the SMP case.
			 */
			if (cpu == this_cpu)
				flush_dcache_page_impl(page);
			else
				smp_flush_dcache_page_impl(page, cpu);

			clear_dcache_dirty_cpu(page, cpu);

			put_cpu();
		}
	}
}

/* mm->context.lock must be held */
static void __update_mmu_tsb_insert(struct mm_struct *mm, unsigned long tsb_index,
				    unsigned long tsb_hash_shift, unsigned long address,
				    unsigned long tte)
{
	struct tsb *tsb = mm->context.tsb_block[tsb_index].tsb;
	unsigned long tag;

	if (unlikely(!tsb))
		return;

	tsb += ((address >> tsb_hash_shift) &
		(mm->context.tsb_block[tsb_index].tsb_nentries - 1UL));
	tag = (address >> 22UL);
	tsb_insert(tsb, tag, tte);
}

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
static inline bool is_hugetlb_pte(pte_t pte)
{
	if ((tlb_type == hypervisor &&
	     (pte_val(pte) & _PAGE_SZALL_4V) == _PAGE_SZHUGE_4V) ||
	    (tlb_type != hypervisor &&
	     (pte_val(pte) & _PAGE_SZALL_4U) == _PAGE_SZHUGE_4U))
		return true;
	return false;
}
#endif

void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
	struct mm_struct *mm;
	unsigned long flags;
	pte_t pte = *ptep;

	if (tlb_type != hypervisor) {
		unsigned long pfn = pte_pfn(pte);

		if (pfn_valid(pfn))
			flush_dcache(pfn);
	}

	mm = vma->vm_mm;

	spin_lock_irqsave(&mm->context.lock, flags);

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
	if (mm->context.huge_pte_count && is_hugetlb_pte(pte))
		__update_mmu_tsb_insert(mm, MM_TSB_HUGE, HPAGE_SHIFT,
					address, pte_val(pte));
	else
#endif
		__update_mmu_tsb_insert(mm, MM_TSB_BASE, PAGE_SHIFT,
					address, pte_val(pte));

	spin_unlock_irqrestore(&mm->context.lock, flags);
}

void flush_dcache_page(struct page *page)
{
	struct address_space *mapping;
	int this_cpu;

	if (tlb_type == hypervisor)
		return;

	/* Do not bother with the expensive D-cache flush if it
	 * is merely the zero page.  The 'bigcore' testcase in GDB
	 * causes this case to run millions of times.
	 */
	if (page == ZERO_PAGE(0))
		return;

	this_cpu = get_cpu();

	mapping = page_mapping(page);
	if (mapping && !mapping_mapped(mapping)) {
		int dirty = test_bit(PG_dcache_dirty, &page->flags);
		if (dirty) {
			int dirty_cpu = dcache_dirty_cpu(page);

			if (dirty_cpu == this_cpu)
				goto out;
			smp_flush_dcache_page_impl(page, dirty_cpu);
		}
		set_dcache_dirty(page, this_cpu);
	} else {
		/* We could delay the flush for the !page_mapping
		 * case too.  But that case is for exec env/arg
		 * pages and those are %99 certainly going to get
		 * faulted into the tlb (and thus flushed) anyways.
		 */
		flush_dcache_page_impl(page);
	}

out:
	put_cpu();
}
EXPORT_SYMBOL(flush_dcache_page);

void __kprobes flush_icache_range(unsigned long start, unsigned long end)
{
	/* Cheetah and Hypervisor platform cpus have coherent I-cache. */
	if (tlb_type == spitfire) {
		unsigned long kaddr;

		/* This code only runs on Spitfire cpus so this is
		 * why we can assume _PAGE_PADDR_4U.
		 */
		for (kaddr = start; kaddr < end; kaddr += PAGE_SIZE) {
			unsigned long paddr, mask = _PAGE_PADDR_4U;

			if (kaddr >= PAGE_OFFSET)
				paddr = kaddr & mask;
			else {
				pgd_t *pgdp = pgd_offset_k(kaddr);
				pud_t *pudp = pud_offset(pgdp, kaddr);
				pmd_t *pmdp = pmd_offset(pudp, kaddr);
				pte_t *ptep = pte_offset_kernel(pmdp, kaddr);

				paddr = pte_val(*ptep) & mask;
			}
			__flush_icache_page(paddr);
		}
	}
}
EXPORT_SYMBOL(flush_icache_range);

void mmu_info(struct seq_file *m)
{
	static const char *pgsz_strings[] = {
		"8K", "64K", "512K", "4MB", "32MB",
		"256MB", "2GB", "16GB",
	};
	int i, printed;

	if (tlb_type == cheetah)
		seq_printf(m, "MMU Type\t: Cheetah\n");
	else if (tlb_type == cheetah_plus)
		seq_printf(m, "MMU Type\t: Cheetah+\n");
	else if (tlb_type == spitfire)
		seq_printf(m, "MMU Type\t: Spitfire\n");
	else if (tlb_type == hypervisor)
		seq_printf(m, "MMU Type\t: Hypervisor (sun4v)\n");
	else
		seq_printf(m, "MMU Type\t: ???\n");

	seq_printf(m, "MMU PGSZs\t: ");
	printed = 0;
	for (i = 0; i < ARRAY_SIZE(pgsz_strings); i++) {
		if (cpu_pgsz_mask & (1UL << i)) {
			seq_printf(m, "%s%s",
				   printed ? "," : "", pgsz_strings[i]);
			printed++;
		}
	}
	seq_putc(m, '\n');

#ifdef CONFIG_DEBUG_DCFLUSH
	seq_printf(m, "DCPageFlushes\t: %d\n",
		   atomic_read(&dcpage_flushes));
#ifdef CONFIG_SMP
	seq_printf(m, "DCPageFlushesXC\t: %d\n",
		   atomic_read(&dcpage_flushes_xcall));
#endif /* CONFIG_SMP */
#endif /* CONFIG_DEBUG_DCFLUSH */
}

struct linux_prom_translation prom_trans[512] __read_mostly;
unsigned int prom_trans_ents __read_mostly;

unsigned long kern_locked_tte_data;

/* The obp translations are saved based on 8k pagesize, since obp can
 * use a mixture of pagesizes. Misses to the LOW_OBP_ADDRESS ->
 * HI_OBP_ADDRESS range are handled in ktlb.S.
 */
static inline int in_obp_range(unsigned long vaddr)
{
	return (vaddr >= LOW_OBP_ADDRESS &&
		vaddr < HI_OBP_ADDRESS);
}

static int cmp_ptrans(const void *a, const void *b)
{
	const struct linux_prom_translation *x = a, *y = b;

	if (x->virt > y->virt)
		return 1;
	if (x->virt < y->virt)
		return -1;
	return 0;
}

/* Read OBP translations property into 'prom_trans[]'.  */
static void __init read_obp_translations(void)
{
	int n, node, ents, first, last, i;

	node = prom_finddevice("/virtual-memory");
	n = prom_getproplen(node, "translations");
	if (unlikely(n == 0 || n == -1)) {
		prom_printf("prom_mappings: Couldn't get size.\n");
		prom_halt();
	}
	if (unlikely(n > sizeof(prom_trans))) {
		prom_printf("prom_mappings: Size %d is too big.\n", n);
		prom_halt();
	}

	if ((n = prom_getproperty(node, "translations",
				  (char *)&prom_trans[0],
				  sizeof(prom_trans))) == -1) {
		prom_printf("prom_mappings: Couldn't get property.\n");
		prom_halt();
	}

	n = n / sizeof(struct linux_prom_translation);

	ents = n;

	sort(prom_trans, ents, sizeof(struct linux_prom_translation),
	     cmp_ptrans, NULL);

	/* Now kick out all the non-OBP entries.  */
	for (i = 0; i < ents; i++) {
		if (in_obp_range(prom_trans[i].virt))
			break;
	}
	first = i;
	for (; i < ents; i++) {
		if (!in_obp_range(prom_trans[i].virt))
			break;
	}
	last = i;

	for (i = 0; i < (last - first); i++) {
		struct linux_prom_translation *src = &prom_trans[i + first];
		struct linux_prom_translation *dest = &prom_trans[i];

		*dest = *src;
	}
	for (; i < ents; i++) {
		struct linux_prom_translation *dest = &prom_trans[i];
		dest->virt = dest->size = dest->data = 0x0UL;
	}

	prom_trans_ents = last - first;

	if (tlb_type == spitfire) {
		/* Clear diag TTE bits. */
		for (i = 0; i < prom_trans_ents; i++)
			prom_trans[i].data &= ~0x0003fe0000000000UL;
	}

	/* Force execute bit on.  */
	for (i = 0; i < prom_trans_ents; i++)
		prom_trans[i].data |= (tlb_type == hypervisor ?
				       _PAGE_EXEC_4V : _PAGE_EXEC_4U);
}

static void __init hypervisor_tlb_lock(unsigned long vaddr,
				       unsigned long pte,
				       unsigned long mmu)
{
	unsigned long ret = sun4v_mmu_map_perm_addr(vaddr, 0, pte, mmu);

	if (ret != 0) {
		prom_printf("hypervisor_tlb_lock[%lx:%x:%lx:%lx]: "
			    "errors with %lx\n", vaddr, 0, pte, mmu, ret);
		prom_halt();
	}
}

static unsigned long kern_large_tte(unsigned long paddr);

static void __init remap_kernel(void)
{
	unsigned long phys_page, tte_vaddr, tte_data;
	int i, tlb_ent = sparc64_highest_locked_tlbent();

	tte_vaddr = (unsigned long) KERNBASE;
	phys_page = (prom_boot_mapping_phys_low >> 22UL) << 22UL;
	tte_data = kern_large_tte(phys_page);

	kern_locked_tte_data = tte_data;

	/* Now lock us into the TLBs via Hypervisor or OBP. */
	if (tlb_type == hypervisor) {
		for (i = 0; i < num_kernel_image_mappings; i++) {
			hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_DMMU);
			hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_IMMU);
			tte_vaddr += 0x400000;
			tte_data += 0x400000;
		}
	} else {
		for (i = 0; i < num_kernel_image_mappings; i++) {
			prom_dtlb_load(tlb_ent - i, tte_data, tte_vaddr);
			prom_itlb_load(tlb_ent - i, tte_data, tte_vaddr);
			tte_vaddr += 0x400000;
			tte_data += 0x400000;
		}
		sparc64_highest_unlocked_tlb_ent = tlb_ent - i;
	}
	if (tlb_type == cheetah_plus) {
		sparc64_kern_pri_context = (CTX_CHEETAH_PLUS_CTX0 |
					    CTX_CHEETAH_PLUS_NUC);
		sparc64_kern_pri_nuc_bits = CTX_CHEETAH_PLUS_NUC;
		sparc64_kern_sec_context = CTX_CHEETAH_PLUS_CTX0;
	}
}


static void __init inherit_prom_mappings(void)
{
	/* Now fixup OBP's idea about where we really are mapped. */
	printk("Remapping the kernel... ");
	remap_kernel();
	printk("done.\n");
}

void prom_world(int enter)
{
	if (!enter)
		set_fs(get_fs());

	__asm__ __volatile__("flushw");
}

void __flush_dcache_range(unsigned long start, unsigned long end)
{
	unsigned long va;

	if (tlb_type == spitfire) {
		int n = 0;

		for (va = start; va < end; va += 32) {
			spitfire_put_dcache_tag(va & 0x3fe0, 0x0);
			if (++n >= 512)
				break;
		}
	} else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
		start = __pa(start);
		end = __pa(end);
		for (va = start; va < end; va += 32)
			__asm__ __volatile__("stxa %%g0, [%0] %1\n\t"
					     "membar #Sync"
					     : /* no outputs */
					     : "r" (va),
					       "i" (ASI_DCACHE_INVALIDATE));
	}
}
EXPORT_SYMBOL(__flush_dcache_range);

/* get_new_mmu_context() uses "cache + 1".  */
DEFINE_SPINLOCK(ctx_alloc_lock);
unsigned long tlb_context_cache = CTX_FIRST_VERSION - 1;
#define MAX_CTX_NR	(1UL << CTX_NR_BITS)
#define CTX_BMAP_SLOTS	BITS_TO_LONGS(MAX_CTX_NR)
DECLARE_BITMAP(mmu_context_bmap, MAX_CTX_NR);

/* Caller does TLB context flushing on local CPU if necessary.
 * The caller also ensures that CTX_VALID(mm->context) is false.
 *
 * We must be careful about boundary cases so that we never
 * let the user have CTX 0 (nucleus) or we ever use a CTX
 * version of zero (and thus NO_CONTEXT would not be caught
 * by version mis-match tests in mmu_context.h).
 *
 * Always invoked with interrupts disabled.
 */
void get_new_mmu_context(struct mm_struct *mm)
{
	unsigned long ctx, new_ctx;
	unsigned long orig_pgsz_bits;
	unsigned long flags;
	int new_version;

	spin_lock_irqsave(&ctx_alloc_lock, flags);
	orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK);
	ctx = (tlb_context_cache + 1) & CTX_NR_MASK;
	new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx);
	new_version = 0;
	if (new_ctx >= (1 << CTX_NR_BITS)) {
		new_ctx = find_next_zero_bit(mmu_context_bmap, ctx, 1);
		if (new_ctx >= ctx) {
			int i;
			new_ctx = (tlb_context_cache & CTX_VERSION_MASK) +
				CTX_FIRST_VERSION;
			if (new_ctx == 1)
				new_ctx = CTX_FIRST_VERSION;

			/* Don't call memset, for 16 entries that's just
			 * plain silly...
			 */
			mmu_context_bmap[0] = 3;
			mmu_context_bmap[1] = 0;
			mmu_context_bmap[2] = 0;
			mmu_context_bmap[3] = 0;
			for (i = 4; i < CTX_BMAP_SLOTS; i += 4) {
				mmu_context_bmap[i + 0] = 0;
				mmu_context_bmap[i + 1] = 0;
				mmu_context_bmap[i + 2] = 0;
				mmu_context_bmap[i + 3] = 0;
			}
			new_version = 1;
			goto out;
		}
	}
	mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63));
	new_ctx |= (tlb_context_cache & CTX_VERSION_MASK);
out:
	tlb_context_cache = new_ctx;
	mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits;
	spin_unlock_irqrestore(&ctx_alloc_lock, flags);

	if (unlikely(new_version))
		smp_new_mmu_context_version();
}

static int numa_enabled = 1;
static int numa_debug;

static int __init early_numa(char *p)
{
	if (!p)
		return 0;

	if (strstr(p, "off"))
		numa_enabled = 0;

	if (strstr(p, "debug"))
		numa_debug = 1;

	return 0;
}
early_param("numa", early_numa);

#define numadbg(f, a...) \
do {	if (numa_debug) \
		printk(KERN_INFO f, ## a); \
} while (0)

static void __init find_ramdisk(unsigned long phys_base)
{
#ifdef CONFIG_BLK_DEV_INITRD
	if (sparc_ramdisk_image || sparc_ramdisk_image64) {
		unsigned long ramdisk_image;

		/* Older versions of the bootloader only supported a
		 * 32-bit physical address for the ramdisk image
		 * location, stored at sparc_ramdisk_image.  Newer
		 * SILO versions set sparc_ramdisk_image to zero and
		 * provide a full 64-bit physical address at
		 * sparc_ramdisk_image64.
		 */
		ramdisk_image = sparc_ramdisk_image;
		if (!ramdisk_image)
			ramdisk_image = sparc_ramdisk_image64;

		/* Another bootloader quirk.  The bootloader normalizes
		 * the physical address to KERNBASE, so we have to
		 * factor that back out and add in the lowest valid
		 * physical page address to get the true physical address.
		 */
		ramdisk_image -= KERNBASE;
		ramdisk_image += phys_base;

		numadbg("Found ramdisk at physical address 0x%lx, size %u\n",
			ramdisk_image, sparc_ramdisk_size);

		initrd_start = ramdisk_image;
		initrd_end = ramdisk_image + sparc_ramdisk_size;

		memblock_reserve(initrd_start, sparc_ramdisk_size);

		initrd_start += PAGE_OFFSET;
		initrd_end += PAGE_OFFSET;
	}
#endif
}

struct node_mem_mask {
	unsigned long mask;
	unsigned long val;
};
static struct node_mem_mask node_masks[MAX_NUMNODES];
static int num_node_masks;

int numa_cpu_lookup_table[NR_CPUS];
cpumask_t numa_cpumask_lookup_table[MAX_NUMNODES];

#ifdef CONFIG_NEED_MULTIPLE_NODES

struct mdesc_mblock {
	u64	base;
	u64	size;
	u64	offset; /* RA-to-PA */
};
static struct mdesc_mblock *mblocks;
static int num_mblocks;

static unsigned long ra_to_pa(unsigned long addr)
{
	int i;

	for (i = 0; i < num_mblocks; i++) {
		struct mdesc_mblock *m = &mblocks[i];

		if (addr >= m->base &&
		    addr < (m->base + m->size)) {
			addr += m->offset;
			break;
		}
	}
	return addr;
}

static int find_node(unsigned long addr)
{
	int i;

	addr = ra_to_pa(addr);
	for (i = 0; i < num_node_masks; i++) {
		struct node_mem_mask *p = &node_masks[i];

		if ((addr & p->mask) == p->val)
			return i;
	}
	return -1;
}

static u64 memblock_nid_range(u64 start, u64 end, int *nid)
{
	*nid = find_node(start);
	start += PAGE_SIZE;
	while (start < end) {
		int n = find_node(start);

		if (n != *nid)
			break;
		start += PAGE_SIZE;
	}

	if (start > end)
		start = end;

	return start;
}
#endif

/* This must be invoked after performing all of the necessary
 * memblock_set_node() calls for 'nid'.  We need to be able to get
 * correct data from get_pfn_range_for_nid().
 */
static void __init allocate_node_data(int nid)
{
	struct pglist_data *p;
	unsigned long start_pfn, end_pfn;
#ifdef CONFIG_NEED_MULTIPLE_NODES
	unsigned long paddr;

	paddr = memblock_alloc_try_nid(sizeof(struct pglist_data), SMP_CACHE_BYTES, nid);
	if (!paddr) {
		prom_printf("Cannot allocate pglist_data for nid[%d]\n", nid);
		prom_halt();
	}
	NODE_DATA(nid) = __va(paddr);
	memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));

	NODE_DATA(nid)->node_id = nid;
#endif

	p = NODE_DATA(nid);

	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
	p->node_start_pfn = start_pfn;
	p->node_spanned_pages = end_pfn - start_pfn;
}

static void init_node_masks_nonnuma(void)
{
	int i;

	numadbg("Initializing tables for non-numa.\n");

	node_masks[0].mask = node_masks[0].val = 0;
	num_node_masks = 1;

	for (i = 0; i < NR_CPUS; i++)
		numa_cpu_lookup_table[i] = 0;

	cpumask_setall(&numa_cpumask_lookup_table[0]);
}

#ifdef CONFIG_NEED_MULTIPLE_NODES
struct pglist_data *node_data[MAX_NUMNODES];

EXPORT_SYMBOL(numa_cpu_lookup_table);
EXPORT_SYMBOL(numa_cpumask_lookup_table);
EXPORT_SYMBOL(node_data);

struct mdesc_mlgroup {
	u64	node;
	u64	latency;
	u64	match;
	u64	mask;
};
static struct mdesc_mlgroup *mlgroups;
static int num_mlgroups;

static int scan_pio_for_cfg_handle(struct mdesc_handle *md, u64 pio,
				   u32 cfg_handle)
{
	u64 arc;

	mdesc_for_each_arc(arc, md, pio, MDESC_ARC_TYPE_FWD) {
		u64 target = mdesc_arc_target(md, arc);
		const u64 *val;

		val = mdesc_get_property(md, target,
					 "cfg-handle", NULL);
		if (val && *val == cfg_handle)
			return 0;
	}
	return -ENODEV;
}

static int scan_arcs_for_cfg_handle(struct mdesc_handle *md, u64 grp,
				    u32 cfg_handle)
{
	u64 arc, candidate, best_latency = ~(u64)0;

	candidate = MDESC_NODE_NULL;
	mdesc_for_each_arc(arc, md, grp, MDESC_ARC_TYPE_FWD) {
		u64 target = mdesc_arc_target(md, arc);
		const char *name = mdesc_node_name(md, target);
		const u64 *val;

		if (strcmp(name, "pio-latency-group"))
			continue;

		val = mdesc_get_property(md, target, "latency", NULL);
		if (!val)
			continue;

		if (*val < best_latency) {
			candidate = target;
			best_latency = *val;
		}
	}

	if (candidate == MDESC_NODE_NULL)
		return -ENODEV;

	return scan_pio_for_cfg_handle(md, candidate, cfg_handle);
}

int of_node_to_nid(struct device_node *dp)
{
	const struct linux_prom64_registers *regs;
	struct mdesc_handle *md;
	u32 cfg_handle;
	int count, nid;
	u64 grp;

	/* This is the right thing to do on currently supported
	 * SUN4U NUMA platforms as well, as the PCI controller does
	 * not sit behind any particular memory controller.
	 */
	if (!mlgroups)
		return -1;

	regs = of_get_property(dp, "reg", NULL);
	if (!regs)
		return -1;

	cfg_handle = (regs->phys_addr >> 32UL) & 0x0fffffff;

	md = mdesc_grab();

	count = 0;
	nid = -1;
	mdesc_for_each_node_by_name(md, grp, "group") {
		if (!scan_arcs_for_cfg_handle(md, grp, cfg_handle)) {
			nid = count;
			break;
		}
		count++;
	}

	mdesc_release(md);