/*
 *  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;
        int new_version;

        spin_lock(&ctx_alloc_lock);
        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(&ctx_alloc_lock);

        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);

        return nid;
}

static void __init add_node_ranges(void)
{
        struct memblock_region *reg;

        for_each_memblock(memory, reg) {
                unsigned long size = reg->size;
                unsigned long start, end;

                start = reg->base;
                end = start + size;
                while (start < end) {
                        unsigned long this_end;
                        int nid;

                        this_end = memblock_nid_range(start, end, &nid);

                        numadbg("Setting memblock NUMA node nid[%d] "
                                "start[%lx] end[%lx]\n",
                                nid, start, this_end);

                        memblock_set_node(start, this_end - start, nid);
                        start = this_end;
                }
        }
}

static int __init grab_mlgroups(struct mdesc_handle *md)
{
        unsigned long paddr;
        int count = 0;
        u64 node;

        mdesc_for_each_node_by_name(md, node, "memory-latency-group")
                count++;
        if (!count)
                return -ENOENT;

        paddr = memblock_alloc(count * sizeof(struct mdesc_mlgroup),
                          SMP_CACHE_BYTES);
        if (!paddr)
                return -ENOMEM;

        mlgroups = __va(paddr);
        num_mlgroups = count;

        count = 0;
        mdesc_for_each_node_by_name(md, node, "memory-latency-group") {
                struct mdesc_mlgroup *m = &mlgroups[count++];
                const u64 *val;

                m->node = node;

                val = mdesc_get_property(md, node, "latency", NULL);
                m->latency = *val;
                val = mdesc_get_property(md, node, "address-match", NULL);
                m->match = *val;
                val = mdesc_get_property(md, node, "address-mask", NULL);
                m->mask = *val;

                numadbg("MLGROUP[%d]: node[%llx] latency[%llx] "
                        "match[%llx] mask[%llx]\n",
                        count - 1, m->node, m->latency, m->match, m->mask);
        }

        return 0;
}

static int __init grab_mblocks(struct mdesc_handle *md)
{
        unsigned long paddr;
        int count = 0;
        u64 node;

        mdesc_for_each_node_by_name(md, node, "mblock")
                count++;
        if (!count)
                return -ENOENT;

        paddr = memblock_alloc(count * sizeof(struct mdesc_mblock),
                          SMP_CACHE_BYTES);
        if (!paddr)
                return -ENOMEM;

        mblocks = __va(paddr);
        num_mblocks = count;

        count = 0;
        mdesc_for_each_node_by_name(md, node, "mblock") {
                struct mdesc_mblock *m = &mblocks[count++];
                const u64 *val;

                val = mdesc_get_property(md, node, "base", NULL);
                m->base = *val;
                val = mdesc_get_property(md, node, "size", NULL);
                m->size = *val;
                val = mdesc_get_property(md, node,
                                         "address-congruence-offset", NULL);

                /* The address-congruence-offset property is optional.
                 * Explicity zero it be identifty this.
                 */
                if (val)
                        m->offset = *val;
                else
                        m->offset = 0UL;

                numadbg("MBLOCK[%d]: base[%llx] size[%llx] offset[%llx]\n",
                        count - 1, m->base, m->size, m->offset);
        }

        return 0;
}

static void __init numa_parse_mdesc_group_cpus(struct mdesc_handle *md,
                                               u64 grp, cpumask_t *mask)
{
        u64 arc;

        cpumask_clear(mask);

        mdesc_for_each_arc(arc, md, grp, MDESC_ARC_TYPE_BACK) {
                u64 target = mdesc_arc_target(md, arc);
                const char *name = mdesc_node_name(md, target);
                const u64 *id;

                if (strcmp(name, "cpu"))
                        continue;
                id = mdesc_get_property(md, target, "id", NULL);
                if (*id < nr_cpu_ids)
                        cpumask_set_cpu(*id, mask);
        }
}

static struct mdesc_mlgroup * __init find_mlgroup(u64 node)
{
        int i;

        for (i = 0; i < num_mlgroups; i++) {
                struct mdesc_mlgroup *m = &mlgroups[i];
                if (m->node == node)
                        return m;
        }
        return NULL;
}

static int __init numa_attach_mlgroup(struct mdesc_handle *md, u64 grp,
                                      int index)
{
        struct mdesc_mlgroup *candidate = NULL;
        u64 arc, best_latency = ~(u64)0;
        struct node_mem_mask *n;

        mdesc_for_each_arc(arc, md, grp, MDESC_ARC_TYPE_FWD) {
                u64 target = mdesc_arc_target(md, arc);
                struct mdesc_mlgroup *m = find_mlgroup(target);
                if (!m)
                        continue;
                if (m->latency < best_latency) {
                        candidate = m;
                        best_latency = m->latency;
                }
        }
        if (!candidate)
                return -ENOENT;

        if (num_node_masks != index) {
                printk(KERN_ERR "Inconsistent NUMA state, "
                       "index[%d] != num_node_masks[%d]\n",
                       index, num_node_masks);
                return -EINVAL;
        }

        n = &node_masks[num_node_masks++];

        n->mask = candidate->mask;
        n->val = candidate->match;

        numadbg("NUMA NODE[%d]: mask[%lx] val[%lx] (latency[%llx])\n",
                index, n->mask, n->val, candidate->latency);

        return 0;
}

static int __init numa_parse_mdesc_group(struct mdesc_handle *md, u64 grp,
                                         int index)
{
        cpumask_t mask;
        int cpu;

        numa_parse_mdesc_group_cpus(md, grp, &mask);

        for_each_cpu(cpu, &mask)
                numa_cpu_lookup_table[cpu] = index;
        cpumask_copy(&numa_cpumask_lookup_table[index], &mask);

        if (numa_debug) {
                printk(KERN_INFO "NUMA GROUP[%d]: cpus [ ", index);
                for_each_cpu(cpu, &mask)
                        printk("%d ", cpu);
                printk("]\n");
        }

        return numa_attach_mlgroup(md, grp, index);
}

static int __init numa_parse_mdesc(void)
{
        struct mdesc_handle *md = mdesc_grab();
        int i, err, count;
        u64 node;

        node = mdesc_node_by_name(md, MDESC_NODE_NULL, "latency-groups");
        if (node == MDESC_NODE_NULL) {
                mdesc_release(md);
                return -ENOENT;
        }

        err = grab_mblocks(md);
        if (err < 0)
                goto out;

        err = grab_mlgroups(md);
        if (err < 0)
                goto out;

        count = 0;
        mdesc_for_each_node_by_name(md, node, "group") {
                err = numa_parse_mdesc_group(md, node, count);
                if (err < 0)
                        break;
                count++;
        }

        add_node_ranges();

        for (i = 0; i < num_node_masks; i++) {
                allocate_node_data(i);
                node_set_online(i);
        }

        err = 0;
out:
        mdesc_release(md);
        return err;
}

static int __init numa_parse_jbus(void)
{
        unsigned long cpu, index;

        /* NUMA node id is encoded in bits 36 and higher, and there is
         * a 1-to-1 mapping from CPU ID to NUMA node ID.
         */
        index = 0;
        for_each_present_cpu(cpu) {
                numa_cpu_lookup_table[cpu] = index;
                cpumask_copy(&numa_cpumask_lookup_table[index], cpumask_of(cpu));
                node_masks[index].mask = ~((1UL << 36UL) - 1UL);
                node_masks[index].val = cpu << 36UL;

                index++;
        }
        num_node_masks = index;

        add_node_ranges();

        for (index = 0; index < num_node_masks; index++) {
                allocate_node_data(index);
                node_set_online(index);
        }

        return 0;
}

static int __init numa_parse_sun4u(void)
{
        if (tlb_type == cheetah || tlb_type == cheetah_plus) {
                unsigned long ver;

                __asm__ ("rdpr %%ver, %0" : "=r" (ver));
                if ((ver >> 32UL) == __JALAPENO_ID ||
                    (ver >> 32UL) == __SERRANO_ID)
                        return numa_parse_jbus();
        }
        return -1;
}

static int __init bootmem_init_numa(void)
{
        int err = -1;

        numadbg("bootmem_init_numa()\n");

        if (numa_enabled) {
                if (tlb_type == hypervisor)
                        err = numa_parse_mdesc();
                else
                        err = numa_parse_sun4u();
        }
        return err;
}

#else

static int bootmem_init_numa(void)
{
        return -1;
}

#endif

static void __init bootmem_init_nonnuma(void)
{
        unsigned long top_of_ram = memblock_end_of_DRAM();
        unsigned long total_ram = memblock_phys_mem_size();

        numadbg("bootmem_init_nonnuma()\n");

        printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
               top_of_ram, total_ram);
        printk(KERN_INFO "Memory hole size: %ldMB\n",
               (top_of_ram - total_ram) >> 20);

        init_node_masks_nonnuma();
        memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
        allocate_node_data(0);
        node_set_online(0);
}

static unsigned long __init bootmem_init(unsigned long phys_base)
{
        unsigned long end_pfn;

        end_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
        max_pfn = max_low_pfn = end_pfn;
        min_low_pfn = (phys_base >> PAGE_SHIFT);

        if (bootmem_init_numa() < 0)
                bootmem_init_nonnuma();

        /* Dump memblock with node info. */
        memblock_dump_all();

        /* XXX cpu notifier XXX */

        sparse_memory_present_with_active_regions(MAX_NUMNODES);
        sparse_init();

        return end_pfn;
}

static struct linux_prom64_registers pall[MAX_BANKS] __initdata;
static int pall_ents __initdata;

#ifdef CONFIG_DEBUG_PAGEALLOC
static unsigned long __ref kernel_map_range(unsigned long pstart,
                                            unsigned long pend, pgprot_t prot)
{
        unsigned long vstart = PAGE_OFFSET + pstart;
        unsigned long vend = PAGE_OFFSET + pend;
        unsigned long alloc_bytes = 0UL;

        if ((vstart & ~PAGE_MASK) || (vend & ~PAGE_MASK)) {
                prom_printf("kernel_map: Unaligned physmem[%lx:%lx]\n",
                            vstart, vend);
                prom_halt();
        }

        while (vstart < vend) {
                unsigned long this_end, paddr = __pa(vstart);
                pgd_t *pgd = pgd_offset_k(vstart);
                pud_t *pud;
                pmd_t *pmd;
                pte_t *pte;

                pud = pud_offset(pgd, vstart);
                if (pud_none(*pud)) {
                        pmd_t *new;

                        new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
                        alloc_bytes += PAGE_SIZE;
                        pud_populate(&init_mm, pud, new);
                }

                pmd = pmd_offset(pud, vstart);
                if (!pmd_present(*pmd)) {
                        pte_t *new;

                        new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
                        alloc_bytes += PAGE_SIZE;
                        pmd_populate_kernel(&init_mm, pmd, new);
                }

                pte = pte_offset_kernel(pmd, vstart);
                this_end = (vstart + PMD_SIZE) & PMD_MASK;
                if (this_end > vend)
                        this_end = vend;

                while (vstart < this_end) {
                        pte_val(*pte) = (paddr | pgprot_val(prot));

                        vstart += PAGE_SIZE;
                        paddr += PAGE_SIZE;
                        pte++;
                }
        }

        return alloc_bytes;
}

extern unsigned int kvmap_linear_patch[1];
#endif /* CONFIG_DEBUG_PAGEALLOC */

static void __init kpte_set_val(unsigned long index, unsigned long val)
{
        unsigned long *ptr = kpte_linear_bitmap;

        val <<= ((index % (BITS_PER_LONG / 2)) * 2);
        ptr += (index / (BITS_PER_LONG / 2));

        *ptr |= val;
}

static const unsigned long kpte_shift_min = 28; /* 256MB */
static const unsigned long kpte_shift_max = 34; /* 16GB */
static const unsigned long kpte_shift_incr = 3;

static unsigned long kpte_mark_using_shift(unsigned long start, unsigned long end,
                                           unsigned long shift)
{
        unsigned long size = (1UL << shift);
        unsigned long mask = (size - 1UL);
        unsigned long remains = end - start;
        unsigned long val;

        if (remains < size || (start & mask))
                return start;

        /* VAL maps:
         *
         *      shift 28 --> kern_linear_pte_xor index 1
         *      shift 31 --> kern_linear_pte_xor index 2
         *      shift 34 --> kern_linear_pte_xor index 3
         */
        val = ((shift - kpte_shift_min) / kpte_shift_incr) + 1;

        remains &= ~mask;
        if (shift != kpte_shift_max)
                remains = size;

        while (remains) {
                unsigned long index = start >> kpte_shift_min;

                kpte_set_val(index, val);

                start += 1UL << kpte_shift_min;
                remains -= 1UL << kpte_shift_min;
        }

        return start;
}

static void __init mark_kpte_bitmap(unsigned long start, unsigned long end)
{
        unsigned long smallest_size, smallest_mask;
        unsigned long s;

        smallest_size = (1UL << kpte_shift_min);
        smallest_mask = (smallest_size - 1UL);

        while (start < end) {
                unsigned long orig_start = start;

                for (s = kpte_shift_max; s >= kpte_shift_min; s -= kpte_shift_incr) {
                        start = kpte_mark_using_shift(start, end, s);

                        if (start != orig_start)
                                break;
                }

                if (start == orig_start)
                        start = (start + smallest_size) & ~smallest_mask;
        }
}

static void __init init_kpte_bitmap(void)
{
        unsigned long i;

        for (i = 0; i < pall_ents; i++) {
                unsigned long phys_start, phys_end;

                phys_start = pall[i].phys_addr;
                phys_end = phys_start + pall[i].reg_size;

                mark_kpte_bitmap(phys_start, phys_end);
        }
}

static void __init kernel_physical_mapping_init(void)
{
#ifdef CONFIG_DEBUG_PAGEALLOC
        unsigned long i, mem_alloced = 0UL;

        for (i = 0; i < pall_ents; i++) {
                unsigned long phys_start, phys_end;

                phys_start = pall[i].phys_addr;
                phys_end = phys_start + pall[i].reg_size;

                mem_alloced += kernel_map_range(phys_start, phys_end,
                                                PAGE_KERNEL);
        }

        printk("Allocated %ld bytes for kernel page tables.\n",
               mem_alloced);

        kvmap_linear_patch[0] = 0x01000000; /* nop */
        flushi(&kvmap_linear_patch[0]);

        __flush_tlb_all();
#endif
}

#ifdef CONFIG_DEBUG_PAGEALLOC
void kernel_map_pages(struct page *page, int numpages, int enable)
{
        unsigned long phys_start = page_to_pfn(page) << PAGE_SHIFT;
        unsigned long phys_end = phys_start + (numpages * PAGE_SIZE);

        kernel_map_range(phys_start, phys_end,
                         (enable ? PAGE_KERNEL : __pgprot(0)));

        flush_tsb_kernel_range(PAGE_OFFSET + phys_start,
                               PAGE_OFFSET + phys_end);

        /* we should perform an IPI and flush all tlbs,
         * but that can deadlock->flush only current cpu.
         */
        __flush_tlb_kernel_range(PAGE_OFFSET + phys_start,
                                 PAGE_OFFSET + phys_end);
}
#endif

unsigned long __init find_ecache_flush_span(unsigned long size)
{
        int i;

        for (i = 0; i < pavail_ents; i++) {
                if (pavail[i].reg_size >= size)
                        return pavail[i].phys_addr;
        }

        return ~0UL;
}

static void __init tsb_phys_patch(void)
{
        struct tsb_ldquad_phys_patch_entry *pquad;
        struct tsb_phys_patch_entry *p;

        pquad = &__tsb_ldquad_phys_patch;
        while (pquad < &__tsb_ldquad_phys_patch_end) {
                unsigned long addr = pquad->addr;

                if (tlb_type == hypervisor)
                        *(unsigned int *) addr = pquad->sun4v_insn;
                else
                        *(unsigned int *) addr = pquad->sun4u_insn;
                wmb();
                __asm__ __volatile__("flush     %0"
                                     : /* no outputs */
                                     : "r" (addr));

                pquad++;
        }

        p = &__tsb_phys_patch;
        while (p < &__tsb_phys_patch_end) {
                unsigned long addr = p->addr;

                *(unsigned int *) addr = p->insn;
                wmb();
                __asm__ __volatile__("flush     %0"
                                     : /* no outputs */
                                     : "r" (addr));

                p++;
        }
}

/* Don't mark as init, we give this to the Hypervisor.  */
#ifndef CONFIG_DEBUG_PAGEALLOC
#define NUM_KTSB_DESCR  2
#else
#define NUM_KTSB_DESCR  1
#endif
static struct hv_tsb_descr ktsb_descr[NUM_KTSB_DESCR];
extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];

static void patch_one_ktsb_phys(unsigned int *start, unsigned int *end, unsigned long pa)
{
        pa >>= KTSB_PHYS_SHIFT;

        while (start < end) {
                unsigned int *ia = (unsigned int *)(unsigned long)*start;

                ia[0] = (ia[0] & ~0x3fffff) | (pa >> 10);
                __asm__ __volatile__("flush     %0" : : "r" (ia));

                ia[1] = (ia[1] & ~0x3ff) | (pa & 0x3ff);
                __asm__ __volatile__("flush     %0" : : "r" (ia + 1));

                start++;
        }
}

static void ktsb_phys_patch(void)
{
        extern unsigned int __swapper_tsb_phys_patch;
        extern unsigned int __swapper_tsb_phys_patch_end;
        unsigned long ktsb_pa;

        ktsb_pa = kern_base + ((unsigned long)&swapper_tsb[0] - KERNBASE);
        patch_one_ktsb_phys(&__swapper_tsb_phys_patch,
                            &__swapper_tsb_phys_patch_end, ktsb_pa);
#ifndef CONFIG_DEBUG_PAGEALLOC
        {
        extern unsigned int __swapper_4m_tsb_phys_patch;
        extern unsigned int __swapper_4m_tsb_phys_patch_end;
        ktsb_pa = (kern_base +
                   ((unsigned long)&swapper_4m_tsb[0] - KERNBASE));
        patch_one_ktsb_phys(&__swapper_4m_tsb_phys_patch,
                            &__swapper_4m_tsb_phys_patch_end, ktsb_pa);
        }
#endif
}

static void __init sun4v_ktsb_init(void)
{
        unsigned long ktsb_pa;

        /* First KTSB for PAGE_SIZE mappings.  */
        ktsb_pa = kern_base + ((unsigned long)&swapper_tsb[0] - KERNBASE);

        switch (PAGE_SIZE) {
        case 8 * 1024:
        default:
                ktsb_descr[0].pgsz_idx = HV_PGSZ_IDX_8K;
                ktsb_descr[0].pgsz_mask = HV_PGSZ_MASK_8K;
                break;

        case 64 * 1024:
                ktsb_descr[0].pgsz_idx = HV_PGSZ_IDX_64K;
                ktsb_descr[0].pgsz_mask = HV_PGSZ_MASK_64K;
                break;

        case 512 * 1024:
                ktsb_descr[0].pgsz_idx = HV_PGSZ_IDX_512K;
                ktsb_descr[0].pgsz_mask = HV_PGSZ_MASK_512K;
                break;

        case 4 * 1024 * 1024:
                ktsb_descr[0].pgsz_idx = HV_PGSZ_IDX_4MB;
                ktsb_descr[0].pgsz_mask = HV_PGSZ_MASK_4MB;
                break;
        }

        ktsb_descr[0].assoc = 1;
        ktsb_descr[0].num_ttes = KERNEL_TSB_NENTRIES;
        ktsb_descr[0].ctx_idx = 0;
        ktsb_descr[0].tsb_base = ktsb_pa;
        ktsb_descr[0].resv = 0;

#ifndef CONFIG_DEBUG_PAGEALLOC
        /* Second KTSB for 4MB/256MB/2GB/16GB mappings.  */
        ktsb_pa = (kern_base +
                   ((unsigned long)&swapper_4m_tsb[0] - KERNBASE));

        ktsb_descr[1].pgsz_idx = HV_PGSZ_IDX_4MB;
        ktsb_descr[1].pgsz_mask = ((HV_PGSZ_MASK_4MB |
                                    HV_PGSZ_MASK_256MB |
                                    HV_PGSZ_MASK_2GB |
                                    HV_PGSZ_MASK_16GB) &
                                   cpu_pgsz_mask);
        ktsb_descr[1].assoc = 1;
        ktsb_descr[1].num_ttes = KERNEL_TSB4M_NENTRIES;
        ktsb_descr[1].ctx_idx = 0;
        ktsb_descr[1].tsb_base = ktsb_pa;
        ktsb_descr[1].resv = 0;
#endif
}

void sun4v_ktsb_register(void)
{
        unsigned long pa, ret;

        pa = kern_base + ((unsigned long)&ktsb_descr[0] - KERNBASE);

        ret = sun4v_mmu_tsb_ctx0(NUM_KTSB_DESCR, pa);
        if (ret != 0) {
                prom_printf("hypervisor_mmu_tsb_ctx0[%lx]: "
                            "errors with %lx\n", pa, ret);
                prom_halt();
        }
}

static void __init sun4u_linear_pte_xor_finalize(void)
{
#ifndef CONFIG_DEBUG_PAGEALLOC
        /* This is where we would add Panther support for
         * 32MB and 256MB pages.
         */
#endif
}

static void __init sun4v_linear_pte_xor_finalize(void)
{
#ifndef CONFIG_DEBUG_PAGEALLOC
        if (cpu_pgsz_mask & HV_PGSZ_MASK_256MB) {
                kern_linear_pte_xor[1] = (_PAGE_VALID | _PAGE_SZ256MB_4V) ^
                        0xfffff80000000000UL;
                kern_linear_pte_xor[1] |= (_PAGE_CP_4V | _PAGE_CV_4V |
                                           _PAGE_P_4V | _PAGE_W_4V);
        } else {
                kern_linear_pte_xor[1] = kern_linear_pte_xor[0];
        }

        if (cpu_pgsz_mask & HV_PGSZ_MASK_2GB) {
                kern_linear_pte_xor[2] = (_PAGE_VALID | _PAGE_SZ2GB_4V) ^
                        0xfffff80000000000UL;
                kern_linear_pte_xor[2] |= (_PAGE_CP_4V | _PAGE_CV_4V |
                                           _PAGE_P_4V | _PAGE_W_4V);
        } else {
                kern_linear_pte_xor[2] = kern_linear_pte_xor[1];
        }

        if (cpu_pgsz_mask & HV_PGSZ_MASK_16GB) {
                kern_linear_pte_xor[3] = (_PAGE_VALID | _PAGE_SZ16GB_4V) ^
                        0xfffff80000000000UL;
                kern_linear_pte_xor[3] |= (_PAGE_CP_4V | _PAGE_CV_4V |
                                           _PAGE_P_4V | _PAGE_W_4V);
        } else {
                kern_linear_pte_xor[3] = kern_linear_pte_xor[2];
        }
#endif
}

/* paging_init() sets up the page tables */

static unsigned long last_valid_pfn;
pgd_t swapper_pg_dir[2048];

static void sun4u_pgprot_init(void);
static void sun4v_pgprot_init(void);

void __init paging_init(void)
{
        unsigned long end_pfn, shift, phys_base;
        unsigned long real_end, i;
        int node;

        /* These build time checkes make sure that the dcache_dirty_cpu()
         * page->flags usage will work.
         *
         * When a page gets marked as dcache-dirty, we store the
         * cpu number starting at bit 32 in the page->flags.  Also,
         * functions like clear_dcache_dirty_cpu use the cpu mask
         * in 13-bit signed-immediate instruction fields.
         */

        /*
         * Page flags must not reach into upper 32 bits that are used
         * for the cpu number
         */
        BUILD_BUG_ON(NR_PAGEFLAGS > 32);

        /*
         * The bit fields placed in the high range must not reach below
         * the 32 bit boundary. Otherwise we cannot place the cpu field
         * at the 32 bit boundary.
         */
        BUILD_BUG_ON(SECTIONS_WIDTH + NODES_WIDTH + ZONES_WIDTH +
                ilog2(roundup_pow_of_two(NR_CPUS)) > 32);

        BUILD_BUG_ON(NR_CPUS > 4096);

        kern_base = (prom_boot_mapping_phys_low >> 22UL) << 22UL;
        kern_size = (unsigned long)&_end - (unsigned long)KERNBASE;

        /* Invalidate both kernel TSBs.  */
        memset(swapper_tsb, 0x40, sizeof(swapper_tsb));
#ifndef CONFIG_DEBUG_PAGEALLOC
        memset(swapper_4m_tsb, 0x40, sizeof(swapper_4m_tsb));
#endif

        if (tlb_type == hypervisor)
                sun4v_pgprot_init();
        else
                sun4u_pgprot_init();

        if (tlb_type == cheetah_plus ||
            tlb_type == hypervisor) {
                tsb_phys_patch();
                ktsb_phys_patch();
        }

        if (tlb_type == hypervisor)
                sun4v_patch_tlb_handlers();

        /* Find available physical memory...
         *
         * Read it twice in order to work around a bug in openfirmware.
         * The call to grab this table itself can cause openfirmware to
         * allocate memory, which in turn can take away some space from
         * the list of available memory.  Reading it twice makes sure
         * we really do get the final value.
         */
        read_obp_translations();
        read_obp_memory("reg", &pall[0], &pall_ents);
        read_obp_memory("available", &pavail[0], &pavail_ents);
        read_obp_memory("available", &pavail[0], &pavail_ents);

        phys_base = 0xffffffffffffffffUL;
        for (i = 0; i < pavail_ents; i++) {
                phys_base = min(phys_base, pavail[i].phys_addr);
                memblock_add(pavail[i].phys_addr, pavail[i].reg_size);
        }

        memblock_reserve(kern_base, kern_size);

        find_ramdisk(phys_base);

        memblock_enforce_memory_limit(cmdline_memory_size);

        memblock_allow_resize();
        memblock_dump_all();

        set_bit(0, mmu_context_bmap);

        shift = kern_base + PAGE_OFFSET - ((unsigned long)KERNBASE);

        real_end = (unsigned long)_end;
        num_kernel_image_mappings = DIV_ROUND_UP(real_end - KERNBASE, 1 << 22);
        printk("Kernel: Using %d locked TLB entries for main kernel image.\n",
               num_kernel_image_mappings);

        /* Set kernel pgd to upper alias so physical page computations
         * work.
         */
        init_mm.pgd += ((shift) / (sizeof(pgd_t)));
        
        memset(swapper_low_pmd_dir, 0, sizeof(swapper_low_pmd_dir));

        /* Now can init the kernel/bad page tables. */
        pud_set(pud_offset(&swapper_pg_dir[0], 0),
                swapper_low_pmd_dir + (shift / sizeof(pgd_t)));
        
        inherit_prom_mappings();
        
        init_kpte_bitmap();

        /* Ok, we can use our TLB miss and window trap handlers safely.  */
        setup_tba();

        __flush_tlb_all();

        prom_build_devicetree();
        of_populate_present_mask();
#ifndef CONFIG_SMP
        of_fill_in_cpu_data();
#endif

        if (tlb_type == hypervisor) {
                sun4v_mdesc_init();
                mdesc_populate_present_mask(cpu_all_mask);
#ifndef CONFIG_SMP
                mdesc_fill_in_cpu_data(cpu_all_mask);
#endif
                mdesc_get_page_sizes(cpu_all_mask, &cpu_pgsz_mask);

                sun4v_linear_pte_xor_finalize();

                sun4v_ktsb_init();
                sun4v_ktsb_register();
        } else {
                unsigned long impl, ver;

                cpu_pgsz_mask = (HV_PGSZ_MASK_8K | HV_PGSZ_MASK_64K |
                                 HV_PGSZ_MASK_512K | HV_PGSZ_MASK_4MB);

                __asm__ __volatile__("rdpr %%ver, %0" : "=r" (ver));
                impl = ((ver >> 32) & 0xffff);
                if (impl == PANTHER_IMPL)
                        cpu_pgsz_mask |= (HV_PGSZ_MASK_32MB |
                                          HV_PGSZ_MASK_256MB);

                sun4u_linear_pte_xor_finalize();
        }

        /* Flush the TLBs and the 4M TSB so that the updated linear
         * pte XOR settings are realized for all mappings.
         */
        __flush_tlb_all();
#ifndef CONFIG_DEBUG_PAGEALLOC
        memset(swapper_4m_tsb, 0x40, sizeof(swapper_4m_tsb));
#endif
        __flush_tlb_all();

        /* Setup bootmem... */
        last_valid_pfn = end_pfn = bootmem_init(phys_base);

        /* Once the OF device tree and MDESC have been setup, we know
         * the list of possible cpus.  Therefore we can allocate the
         * IRQ stacks.
         */
        for_each_possible_cpu(i) {
                node = cpu_to_node(i);

                softirq_stack[i] = __alloc_bootmem_node(NODE_DATA(node),
                                                        THREAD_SIZE,
                                                        THREAD_SIZE, 0);
                hardirq_stack[i] = __alloc_bootmem_node(NODE_DATA(node),
                                                        THREAD_SIZE,
                                                        THREAD_SIZE, 0);
        }

        kernel_physical_mapping_init();

        {
                unsigned long max_zone_pfns[MAX_NR_ZONES];

                memset(max_zone_pfns, 0, sizeof(max_zone_pfns));

                max_zone_pfns[ZONE_NORMAL] = end_pfn;

                free_area_init_nodes(max_zone_pfns);
        }

        printk("Booting Linux...\n");
}

int page_in_phys_avail(unsigned long paddr)
{
        int i;

        paddr &= PAGE_MASK;

        for (i = 0; i < pavail_ents; i++) {
                unsigned long start, end;

                start = pavail[i].phys_addr;
                end = start + pavail[i].reg_size;

                if (paddr >= start && paddr < end)
                        return 1;
        }
        if (paddr >= kern_base && paddr < (kern_base + kern_size))
                return 1;
#ifdef CONFIG_BLK_DEV_INITRD
        if (paddr >= __pa(initrd_start) &&
            paddr < __pa(PAGE_ALIGN(initrd_end)))
                return 1;
#endif

        return 0;
}

static struct linux_prom64_registers pavail_rescan[MAX_BANKS] __initdata;
static int pavail_rescan_ents __initdata;

/* Certain OBP calls, such as fetching "available" properties, can
 * claim physical memory.  So, along with initializing the valid
 * address bitmap, what we do here is refetch the physical available
 * memory list again, and make sure it provides at least as much
 * memory as 'pavail' does.
 */
static void __init setup_valid_addr_bitmap_from_pavail(unsigned long *bitmap)
{
        int i;

        read_obp_memory("available", &pavail_rescan[0], &pavail_rescan_ents);

        for (i = 0; i < pavail_ents; i++) {
                unsigned long old_start, old_end;

                old_start = pavail[i].phys_addr;
                old_end = old_start + pavail[i].reg_size;
                while (old_start < old_end) {
                        int n;

                        for (n = 0; n < pavail_rescan_ents; n++) {
                                unsigned long new_start, new_end;

                                new_start = pavail_rescan[n].phys_addr;
                                new_end = new_start +
                                        pavail_rescan[n].reg_size;

                                if (new_start <= old_start &&
                                    new_end >= (old_start + PAGE_SIZE)) {
                                        set_bit(old_start >> 22, bitmap);
                                        goto do_next_page;
                                }
                        }

                        prom_printf("mem_init: Lost memory in pavail\n");
                        prom_printf("mem_init: OLD start[%lx] size[%lx]\n",
                                    pavail[i].phys_addr,
                                    pavail[i].reg_size);
                        prom_printf("mem_init: NEW start[%lx] size[%lx]\n",
                                    pavail_rescan[i].phys_addr,
                                    pavail_rescan[i].reg_size);
                        prom_printf("mem_init: Cannot continue, aborting.\n");
                        prom_halt();

                do_next_page:
                        old_start += PAGE_SIZE;
                }
        }
}

static void __init patch_tlb_miss_handler_bitmap(void)
{
        extern unsigned int valid_addr_bitmap_insn[];
        extern unsigned int valid_addr_bitmap_patch[];

        valid_addr_bitmap_insn[1] = valid_addr_bitmap_patch[1];
        mb();
        valid_addr_bitmap_insn[0] = valid_addr_bitmap_patch[0];
        flushi(&valid_addr_bitmap_insn[0]);
}

static void __init register_page_bootmem_info(void)
{
#ifdef CONFIG_NEED_MULTIPLE_NODES
        int i;

        for_each_online_node(i)
                if (NODE_DATA(i)->node_spanned_pages)
                        register_page_bootmem_info_node(NODE_DATA(i));
#endif
}
void __init mem_init(void)
{
        unsigned long addr, last;

        addr = PAGE_OFFSET + kern_base;
        last = PAGE_ALIGN(kern_size) + addr;
        while (addr < last) {
                set_bit(__pa(addr) >> 22, sparc64_valid_addr_bitmap);
                addr += PAGE_SIZE;
        }

        setup_valid_addr_bitmap_from_pavail(sparc64_valid_addr_bitmap);
        patch_tlb_miss_handler_bitmap();

        high_memory = __va(last_valid_pfn << PAGE_SHIFT);

        register_page_bootmem_info();
        free_all_bootmem();

        /*
         * Set up the zero page, mark it reserved, so that page count
         * is not manipulated when freeing the page from user ptes.
         */
        mem_map_zero = alloc_pages(GFP_KERNEL|__GFP_ZERO, 0);
        if (mem_map_zero == NULL) {
                prom_printf("paging_init: Cannot alloc zero page.\n");
                prom_halt();
        }
        mark_page_reserved(mem_map_zero);

        mem_init_print_info(NULL);

        if (tlb_type == cheetah || tlb_type == cheetah_plus)
                cheetah_ecache_flush_init();
}

void free_initmem(void)
{
        unsigned long addr, initend;
        int do_free = 1;

        /* If the physical memory maps were trimmed by kernel command
         * line options, don't even try freeing this initmem stuff up.
         * The kernel image could have been in the trimmed out region
         * and if so the freeing below will free invalid page structs.
         */
        if (cmdline_memory_size)
                do_free = 0;

        /*
         * The init section is aligned to 8k in vmlinux.lds. Page align for >8k pagesizes.
         */
        addr = PAGE_ALIGN((unsigned long)(__init_begin));
        initend = (unsigned long)(__init_end) & PAGE_MASK;
        for (; addr < initend; addr += PAGE_SIZE) {
                unsigned long page;

                page = (addr +
                        ((unsigned long) __va(kern_base)) -
                        ((unsigned long) KERNBASE));
                memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);

                if (do_free)
                        free_reserved_page(virt_to_page(page));
        }
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
        free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
                           "initrd");
}
#endif

#define _PAGE_CACHE_4U  (_PAGE_CP_4U | _PAGE_CV_4U)
#define _PAGE_CACHE_4V  (_PAGE_CP_4V | _PAGE_CV_4V)
#define __DIRTY_BITS_4U  (_PAGE_MODIFIED_4U | _PAGE_WRITE_4U | _PAGE_W_4U)
#define __DIRTY_BITS_4V  (_PAGE_MODIFIED_4V | _PAGE_WRITE_4V | _PAGE_W_4V)
#define __ACCESS_BITS_4U (_PAGE_ACCESSED_4U | _PAGE_READ_4U | _PAGE_R)
#define __ACCESS_BITS_4V (_PAGE_ACCESSED_4V | _PAGE_READ_4V | _PAGE_R)

pgprot_t PAGE_KERNEL __read_mostly;
EXPORT_SYMBOL(PAGE_KERNEL);

pgprot_t PAGE_KERNEL_LOCKED __read_mostly;
pgprot_t PAGE_COPY __read_mostly;

pgprot_t PAGE_SHARED __read_mostly;
EXPORT_SYMBOL(PAGE_SHARED);

unsigned long pg_iobits __read_mostly;

unsigned long _PAGE_IE __read_mostly;
EXPORT_SYMBOL(_PAGE_IE);

unsigned long _PAGE_E __read_mostly;
EXPORT_SYMBOL(_PAGE_E);

unsigned long _PAGE_CACHE __read_mostly;
EXPORT_SYMBOL(_PAGE_CACHE);

#ifdef CONFIG_SPARSEMEM_VMEMMAP
unsigned long vmemmap_table[VMEMMAP_SIZE];

static long __meminitdata addr_start, addr_end;
static int __meminitdata node_start;

int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend,
                               int node)
{
        unsigned long phys_start = (vstart - VMEMMAP_BASE);
        unsigned long phys_end = (vend - VMEMMAP_BASE);
        unsigned long addr = phys_start & VMEMMAP_CHUNK_MASK;
        unsigned long end = VMEMMAP_ALIGN(phys_end);
        unsigned long pte_base;

        pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4U |
                    _PAGE_CP_4U | _PAGE_CV_4U |
                    _PAGE_P_4U | _PAGE_W_4U);
        if (tlb_type == hypervisor)
                pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4V |
                            _PAGE_CP_4V | _PAGE_CV_4V |
                            _PAGE_P_4V | _PAGE_W_4V);

        for (; addr < end; addr += VMEMMAP_CHUNK) {
                unsigned long *vmem_pp =
                        vmemmap_table + (addr >> VMEMMAP_CHUNK_SHIFT);
                void *block;

                if (!(*vmem_pp & _PAGE_VALID)) {
                        block = vmemmap_alloc_block(1UL << 22, node);
                        if (!block)
                                return -ENOMEM;

                        *vmem_pp = pte_base | __pa(block);

                        /* check to see if we have contiguous blocks */
                        if (addr_end != addr || node_start != node) {
                                if (addr_start)
                                        printk(KERN_DEBUG " [%lx-%lx] on node %d\n",
                                               addr_start, addr_end-1, node_start);
                                addr_start = addr;
                                node_start = node;
                        }
                        addr_end = addr + VMEMMAP_CHUNK;
                }
        }
        return 0;
}

void __meminit vmemmap_populate_print_last(void)
{
        if (addr_start) {
                printk(KERN_DEBUG " [%lx-%lx] on node %d\n",
                       addr_start, addr_end-1, node_start);
                addr_start = 0;
                addr_end = 0;
                node_start = 0;
        }
}

void vmemmap_free(unsigned long start, unsigned long end)
{
}

#endif /* CONFIG_SPARSEMEM_VMEMMAP */

static void prot_init_common(unsigned long page_none,
                             unsigned long page_shared,
                             unsigned long page_copy,
                             unsigned long page_readonly,
                             unsigned long page_exec_bit)
{
        PAGE_COPY = __pgprot(page_copy);
        PAGE_SHARED = __pgprot(page_shared);

        protection_map[0x0] = __pgprot(page_none);
        protection_map[0x1] = __pgprot(page_readonly & ~page_exec_bit);
        protection_map[0x2] = __pgprot(page_copy & ~page_exec_bit);
        protection_map[0x3] = __pgprot(page_copy & ~page_exec_bit);
        protection_map[0x4] = __pgprot(page_readonly);
        protection_map[0x5] = __pgprot(page_readonly);
        protection_map[0x6] = __pgprot(page_copy);
        protection_map[0x7] = __pgprot(page_copy);
        protection_map[0x8] = __pgprot(page_none);
        protection_map[0x9] = __pgprot(page_readonly & ~page_exec_bit);
        protection_map[0xa] = __pgprot(page_shared & ~page_exec_bit);
        protection_map[0xb] = __pgprot(page_shared & ~page_exec_bit);
        protection_map[0xc] = __pgprot(page_readonly);
        protection_map[0xd] = __pgprot(page_readonly);
        protection_map[0xe] = __pgprot(page_shared);
        protection_map[0xf] = __pgprot(page_shared);
}

static void __init sun4u_pgprot_init(void)
{
        unsigned long page_none, page_shared, page_copy, page_readonly;
        unsigned long page_exec_bit;
        int i;

        PAGE_KERNEL = __pgprot (_PAGE_PRESENT_4U | _PAGE_VALID |
                                _PAGE_CACHE_4U | _PAGE_P_4U |
                                __ACCESS_BITS_4U | __DIRTY_BITS_4U |
                                _PAGE_EXEC_4U);
        PAGE_KERNEL_LOCKED = __pgprot (_PAGE_PRESENT_4U | _PAGE_VALID |
                                       _PAGE_CACHE_4U | _PAGE_P_4U |
                                       __ACCESS_BITS_4U | __DIRTY_BITS_4U |
                                       _PAGE_EXEC_4U | _PAGE_L_4U);

        _PAGE_IE = _PAGE_IE_4U;
        _PAGE_E = _PAGE_E_4U;
        _PAGE_CACHE = _PAGE_CACHE_4U;

        pg_iobits = (_PAGE_VALID | _PAGE_PRESENT_4U | __DIRTY_BITS_4U |
                     __ACCESS_BITS_4U | _PAGE_E_4U);

#ifdef CONFIG_DEBUG_PAGEALLOC
        kern_linear_pte_xor[0] = _PAGE_VALID ^ 0xfffff80000000000UL;
#else
        kern_linear_pte_xor[0] = (_PAGE_VALID | _PAGE_SZ4MB_4U) ^
                0xfffff80000000000UL;
#endif
        kern_linear_pte_xor[0] |= (_PAGE_CP_4U | _PAGE_CV_4U |
                                   _PAGE_P_4U | _PAGE_W_4U);

        for (i = 1; i < 4; i++)
                kern_linear_pte_xor[i] = kern_linear_pte_xor[0];

        _PAGE_ALL_SZ_BITS =  (_PAGE_SZ4MB_4U | _PAGE_SZ512K_4U |
                              _PAGE_SZ64K_4U | _PAGE_SZ8K_4U |
                              _PAGE_SZ32MB_4U | _PAGE_SZ256MB_4U);


        page_none = _PAGE_PRESENT_4U | _PAGE_ACCESSED_4U | _PAGE_CACHE_4U;
        page_shared = (_PAGE_VALID | _PAGE_PRESENT_4U | _PAGE_CACHE_4U |
                       __ACCESS_BITS_4U | _PAGE_WRITE_4U | _PAGE_EXEC_4U);
        page_copy   = (_PAGE_VALID | _PAGE_PRESENT_4U | _PAGE_CACHE_4U |
                       __ACCESS_BITS_4U | _PAGE_EXEC_4U);
        page_readonly   = (_PAGE_VALID | _PAGE_PRESENT_4U | _PAGE_CACHE_4U |
                           __ACCESS_BITS_4U | _PAGE_EXEC_4U);

        page_exec_bit = _PAGE_EXEC_4U;

        prot_init_common(page_none, page_shared, page_copy, page_readonly,
                         page_exec_bit);
}

static void __init sun4v_pgprot_init(void)
{
        unsigned long page_none, page_shared, page_copy, page_readonly;
        unsigned long page_exec_bit;
        int i;

        PAGE_KERNEL = __pgprot (_PAGE_PRESENT_4V | _PAGE_VALID |
                                _PAGE_CACHE_4V | _PAGE_P_4V |
                                __ACCESS_BITS_4V | __DIRTY_BITS_4V |
                                _PAGE_EXEC_4V);
        PAGE_KERNEL_LOCKED = PAGE_KERNEL;

        _PAGE_IE = _PAGE_IE_4V;
        _PAGE_E = _PAGE_E_4V;
        _PAGE_CACHE = _PAGE_CACHE_4V;

#ifdef CONFIG_DEBUG_PAGEALLOC
        kern_linear_pte_xor[0] = _PAGE_VALID ^ 0xfffff80000000000UL;
#else
        kern_linear_pte_xor[0] = (_PAGE_VALID | _PAGE_SZ4MB_4V) ^
                0xfffff80000000000UL;
#endif
        kern_linear_pte_xor[0] |= (_PAGE_CP_4V | _PAGE_CV_4V |
                                   _PAGE_P_4V | _PAGE_W_4V);

        for (i = 1; i < 4; i++)
                kern_linear_pte_xor[i] = kern_linear_pte_xor[0];

        pg_iobits = (_PAGE_VALID | _PAGE_PRESENT_4V | __DIRTY_BITS_4V |
                     __ACCESS_BITS_4V | _PAGE_E_4V);

        _PAGE_ALL_SZ_BITS = (_PAGE_SZ16GB_4V | _PAGE_SZ2GB_4V |
                             _PAGE_SZ256MB_4V | _PAGE_SZ32MB_4V |
                             _PAGE_SZ4MB_4V | _PAGE_SZ512K_4V |
                             _PAGE_SZ64K_4V | _PAGE_SZ8K_4V);

        page_none = _PAGE_PRESENT_4V | _PAGE_ACCESSED_4V | _PAGE_CACHE_4V;
        page_shared = (_PAGE_VALID | _PAGE_PRESENT_4V | _PAGE_CACHE_4V |
                       __ACCESS_BITS_4V | _PAGE_WRITE_4V | _PAGE_EXEC_4V);
        page_copy   = (_PAGE_VALID | _PAGE_PRESENT_4V | _PAGE_CACHE_4V |
                       __ACCESS_BITS_4V | _PAGE_EXEC_4V);
        page_readonly = (_PAGE_VALID | _PAGE_PRESENT_4V | _PAGE_CACHE_4V |
                         __ACCESS_BITS_4V | _PAGE_EXEC_4V);

        page_exec_bit = _PAGE_EXEC_4V;

        prot_init_common(page_none, page_shared, page_copy, page_readonly,
                         page_exec_bit);
}

unsigned long pte_sz_bits(unsigned long sz)
{
        if (tlb_type == hypervisor) {
                switch (sz) {
                case 8 * 1024:
                default:
                        return _PAGE_SZ8K_4V;
                case 64 * 1024:
                        return _PAGE_SZ64K_4V;
                case 512 * 1024:
                        return _PAGE_SZ512K_4V;
                case 4 * 1024 * 1024:
                        return _PAGE_SZ4MB_4V;
                }
        } else {
                switch (sz) {
                case 8 * 1024:
                default:
                        return _PAGE_SZ8K_4U;
                case 64 * 1024:
                        return _PAGE_SZ64K_4U;
                case 512 * 1024:
                        return _PAGE_SZ512K_4U;
                case 4 * 1024 * 1024:
                        return _PAGE_SZ4MB_4U;
                }
        }
}

pte_t mk_pte_io(unsigned long page, pgprot_t prot, int space, unsigned long page_size)
{
        pte_t pte;

        pte_val(pte)  = page | pgprot_val(pgprot_noncached(prot));
        pte_val(pte) |= (((unsigned long)space) << 32);
        pte_val(pte) |= pte_sz_bits(page_size);

        return pte;
}

static unsigned long kern_large_tte(unsigned long paddr)
{
        unsigned long val;

        val = (_PAGE_VALID | _PAGE_SZ4MB_4U |
               _PAGE_CP_4U | _PAGE_CV_4U | _PAGE_P_4U |
               _PAGE_EXEC_4U | _PAGE_L_4U | _PAGE_W_4U);
        if (tlb_type == hypervisor)
                val = (_PAGE_VALID | _PAGE_SZ4MB_4V |
                       _PAGE_CP_4V | _PAGE_CV_4V | _PAGE_P_4V |
                       _PAGE_EXEC_4V | _PAGE_W_4V);

        return val | paddr;
}

/* If not locked, zap it. */
void __flush_tlb_all(void)
{
        unsigned long pstate;
        int i;

        __asm__ __volatile__("flushw\n\t"
                             "rdpr      %%pstate, %0\n\t"
                             "wrpr      %0, %1, %%pstate"
                             : "=r" (pstate)
                             : "i" (PSTATE_IE));
        if (tlb_type == hypervisor) {
                sun4v_mmu_demap_all();
        } else if (tlb_type == spitfire) {
                for (i = 0; i < 64; i++) {
                        /* Spitfire Errata #32 workaround */
                        /* NOTE: Always runs on spitfire, so no
                         *       cheetah+ page size encodings.
                         */
                        __asm__ __volatile__("stxa      %0, [%1] %2\n\t"
                                             "flush     %%g6"
                                             : /* No outputs */
                                             : "r" (0),
                                             "r" (PRIMARY_CONTEXT), "i" (ASI_DMMU));

                        if (!(spitfire_get_dtlb_data(i) & _PAGE_L_4U)) {
                                __asm__ __volatile__("stxa %%g0, [%0] %1\n\t"
                                                     "membar #Sync"
                                                     : /* no outputs */
                                                     : "r" (TLB_TAG_ACCESS), "i" (ASI_DMMU));
                                spitfire_put_dtlb_data(i, 0x0UL);
                        }

                        /* Spitfire Errata #32 workaround */
                        /* NOTE: Always runs on spitfire, so no
                         *       cheetah+ page size encodings.
                         */
                        __asm__ __volatile__("stxa      %0, [%1] %2\n\t"
                                             "flush     %%g6"
                                             : /* No outputs */
                                             : "r" (0),
                                             "r" (PRIMARY_CONTEXT), "i" (ASI_DMMU));

                        if (!(spitfire_get_itlb_data(i) & _PAGE_L_4U)) {
                                __asm__ __volatile__("stxa %%g0, [%0] %1\n\t"
                                                     "membar #Sync"
                                                     : /* no outputs */
                                                     : "r" (TLB_TAG_ACCESS), "i" (ASI_IMMU));
                                spitfire_put_itlb_data(i, 0x0UL);
                        }
                }
        } else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
                cheetah_flush_dtlb_all();
                cheetah_flush_itlb_all();
        }
        __asm__ __volatile__("wrpr      %0, 0, %%pstate"
                             : : "r" (pstate));
}

static pte_t *get_from_cache(struct mm_struct *mm)
{
        struct page *page;
        pte_t *ret;

        spin_lock(&mm->page_table_lock);
        page = mm->context.pgtable_page;
        ret = NULL;
        if (page) {
                void *p = page_address(page);

                mm->context.pgtable_page = NULL;

                ret = (pte_t *) (p + (PAGE_SIZE / 2));
        }
        spin_unlock(&mm->page_table_lock);

        return ret;
}

static struct page *__alloc_for_cache(struct mm_struct *mm)
{
        struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK |
                                       __GFP_REPEAT | __GFP_ZERO);

        if (page) {
                spin_lock(&mm->page_table_lock);
                if (!mm->context.pgtable_page) {
                        atomic_set(&page->_count, 2);
                        mm->context.pgtable_page = page;
                }
                spin_unlock(&mm->page_table_lock);
        }
        return page;
}

pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
                            unsigned long address)
{
        struct page *page;
        pte_t *pte;

        pte = get_from_cache(mm);
        if (pte)
                return pte;

        page = __alloc_for_cache(mm);
        if (page)
                pte = (pte_t *) page_address(page);

        return pte;
}

pgtable_t pte_alloc_one(struct mm_struct *mm,
                        unsigned long address)
{
        struct page *page;
        pte_t *pte;

        pte = get_from_cache(mm);
        if (pte)
                return pte;

        page = __alloc_for_cache(mm);
        if (page) {
                pgtable_page_ctor(page);
                pte = (pte_t *) page_address(page);
        }

        return pte;
}

void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
        struct page *page = virt_to_page(pte);
        if (put_page_testzero(page))
                free_hot_cold_page(page, 0);
}

static void __pte_free(pgtable_t pte)
{
        struct page *page = virt_to_page(pte);
        if (put_page_testzero(page)) {
                pgtable_page_dtor(page);
                free_hot_cold_page(page, 0);
        }
}

void pte_free(struct mm_struct *mm, pgtable_t pte)
{
        __pte_free(pte);
}

void pgtable_free(void *table, bool is_page)
{
        if (is_page)
                __pte_free(table);
        else
                kmem_cache_free(pgtable_cache, table);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot, bool for_modify)
{
        if (pgprot_val(pgprot) & _PAGE_VALID)
                pmd_val(pmd) |= PMD_HUGE_PRESENT;
        if (tlb_type == hypervisor) {
                if (pgprot_val(pgprot) & _PAGE_WRITE_4V)
                        pmd_val(pmd) |= PMD_HUGE_WRITE;
                if (pgprot_val(pgprot) & _PAGE_EXEC_4V)
                        pmd_val(pmd) |= PMD_HUGE_EXEC;

                if (!for_modify) {
                        if (pgprot_val(pgprot) & _PAGE_ACCESSED_4V)
                                pmd_val(pmd) |= PMD_HUGE_ACCESSED;
                        if (pgprot_val(pgprot) & _PAGE_MODIFIED_4V)
                                pmd_val(pmd) |= PMD_HUGE_DIRTY;
                }
        } else {
                if (pgprot_val(pgprot) & _PAGE_WRITE_4U)
                        pmd_val(pmd) |= PMD_HUGE_WRITE;
                if (pgprot_val(pgprot) & _PAGE_EXEC_4U)
                        pmd_val(pmd) |= PMD_HUGE_EXEC;

                if (!for_modify) {
                        if (pgprot_val(pgprot) & _PAGE_ACCESSED_4U)
                                pmd_val(pmd) |= PMD_HUGE_ACCESSED;
                        if (pgprot_val(pgprot) & _PAGE_MODIFIED_4U)
                                pmd_val(pmd) |= PMD_HUGE_DIRTY;
                }
        }

        return pmd;
}

pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
        pmd_t pmd;

        pmd_val(pmd) = (page_nr << ((PAGE_SHIFT - PMD_PADDR_SHIFT)));
        pmd_val(pmd) |= PMD_ISHUGE;
        pmd = pmd_set_protbits(pmd, pgprot, false);
        return pmd;
}

pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
        pmd_val(pmd) &= ~(PMD_HUGE_PRESENT |
                          PMD_HUGE_WRITE |
                          PMD_HUGE_EXEC);
        pmd = pmd_set_protbits(pmd, newprot, true);
        return pmd;
}

pgprot_t pmd_pgprot(pmd_t entry)
{
        unsigned long pte = 0;

        if (pmd_val(entry) & PMD_HUGE_PRESENT)
                pte |= _PAGE_VALID;

        if (tlb_type == hypervisor) {
                if (pmd_val(entry) & PMD_HUGE_PRESENT)
                        pte |= _PAGE_PRESENT_4V;
                if (pmd_val(entry) & PMD_HUGE_EXEC)
                        pte |= _PAGE_EXEC_4V;
                if (pmd_val(entry) & PMD_HUGE_WRITE)
                        pte |= _PAGE_W_4V;
                if (pmd_val(entry) & PMD_HUGE_ACCESSED)
                        pte |= _PAGE_ACCESSED_4V;
                if (pmd_val(entry) & PMD_HUGE_DIRTY)
                        pte |= _PAGE_MODIFIED_4V;
                pte |= _PAGE_CP_4V|_PAGE_CV_4V;
        } else {
                if (pmd_val(entry) & PMD_HUGE_PRESENT)
                        pte |= _PAGE_PRESENT_4U;
                if (pmd_val(entry) & PMD_HUGE_EXEC)
                        pte |= _PAGE_EXEC_4U;
                if (pmd_val(entry) & PMD_HUGE_WRITE)
                        pte |= _PAGE_W_4U;
                if (pmd_val(entry) & PMD_HUGE_ACCESSED)
                        pte |= _PAGE_ACCESSED_4U;
                if (pmd_val(entry) & PMD_HUGE_DIRTY)
                        pte |= _PAGE_MODIFIED_4U;
                pte |= _PAGE_CP_4U|_PAGE_CV_4U;
        }

        return __pgprot(pte);
}

void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
                          pmd_t *pmd)
{
        unsigned long pte, flags;
        struct mm_struct *mm;
        pmd_t entry = *pmd;
        pgprot_t prot;

        if (!pmd_large(entry) || !pmd_young(entry))
                return;

        pte = (pmd_val(entry) & ~PMD_HUGE_PROTBITS);
        pte <<= PMD_PADDR_SHIFT;
        pte |= _PAGE_VALID;

        prot = pmd_pgprot(entry);

        if (tlb_type == hypervisor)
                pgprot_val(prot) |= _PAGE_SZHUGE_4V;
        else
                pgprot_val(prot) |= _PAGE_SZHUGE_4U;

        pte |= pgprot_val(prot);

        mm = vma->vm_mm;

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

        if (mm->context.tsb_block[MM_TSB_HUGE].tsb != NULL)
                __update_mmu_tsb_insert(mm, MM_TSB_HUGE, HPAGE_SHIFT,
                                        addr, pte);

        spin_unlock_irqrestore(&mm->context.lock, flags);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
static void context_reload(void *__data)
{
        struct mm_struct *mm = __data;

        if (mm == current->mm)
                load_secondary_context(mm);
}

void hugetlb_setup(struct pt_regs *regs)
{
        struct mm_struct *mm = current->mm;
        struct tsb_config *tp;

        if (in_atomic() || !mm) {
                const struct exception_table_entry *entry;

                entry = search_exception_tables(regs->tpc);
                if (entry) {
                        regs->tpc = entry->fixup;
                        regs->tnpc = regs->tpc + 4;
                        return;
                }
                pr_alert("Unexpected HugeTLB setup in atomic context.\n");
                die_if_kernel("HugeTSB in atomic", regs);
        }

        tp = &mm->context.tsb_block[MM_TSB_HUGE];
        if (likely(tp->tsb == NULL))
                tsb_grow(mm, MM_TSB_HUGE, 0);

        tsb_context_switch(mm);
        smp_tsb_sync(mm);

        /* On UltraSPARC-III+ and later, configure the second half of
         * the Data-TLB for huge pages.
         */
        if (tlb_type == cheetah_plus) {
                unsigned long ctx;

                spin_lock(&ctx_alloc_lock);
                ctx = mm->context.sparc64_ctx_val;
                ctx &= ~CTX_PGSZ_MASK;
                ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
                ctx |= CTX_PGSZ_HUGE << CTX_PGSZ1_SHIFT;

                if (ctx != mm->context.sparc64_ctx_val) {
                        /* When changing the page size fields, we
                         * must perform a context flush so that no
                         * stale entries match.  This flush must
                         * occur with the original context register
                         * settings.
                         */
                        do_flush_tlb_mm(mm);

                        /* Reload the context register of all processors
                         * also executing in this address space.
                         */
                        mm->context.sparc64_ctx_val = ctx;
                        on_each_cpu(context_reload, mm, 0);
                }
                spin_unlock(&ctx_alloc_lock);
        }
}
#endif