sparc32: use the common implementation of alloc_thread_info_node()

[linux-2.6/btrfs-unstable.git] / arch / sparc / mm / srmmu.c

/*
 * srmmu.c:  SRMMU specific routines for memory management.
 *
 * Copyright (C) 1995 David S. Miller  (davem@caip.rutgers.edu)
 * Copyright (C) 1995,2002 Pete Zaitcev (zaitcev@yahoo.com)
 * Copyright (C) 1996 Eddie C. Dost    (ecd@skynet.be)
 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1999,2000 Anton Blanchard (anton@samba.org)
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/kdebug.h>
#include <linux/log2.h>
#include <linux/gfp.h>

#include <asm/bitext.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/vaddrs.h>
#include <asm/traps.h>
#include <asm/smp.h>
#include <asm/mbus.h>
#include <asm/cache.h>
#include <asm/oplib.h>
#include <asm/asi.h>
#include <asm/msi.h>
#include <asm/mmu_context.h>
#include <asm/io-unit.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

/* Now the cpu specific definitions. */
#include <asm/viking.h>
#include <asm/mxcc.h>
#include <asm/ross.h>
#include <asm/tsunami.h>
#include <asm/swift.h>
#include <asm/turbosparc.h>
#include <asm/leon.h>

#include "srmmu.h"

enum mbus_module srmmu_modtype;
static unsigned int hwbug_bitmask;
int vac_cache_size;
int vac_line_size;

struct ctx_list *ctx_list_pool;
struct ctx_list ctx_free;
struct ctx_list ctx_used;

extern struct resource sparc_iomap;

extern unsigned long last_valid_pfn;

static pgd_t *srmmu_swapper_pg_dir;

const struct sparc32_cachetlb_ops *sparc32_cachetlb_ops;

#ifdef CONFIG_SMP
const struct sparc32_cachetlb_ops *local_ops;

#define FLUSH_BEGIN(mm)
#define FLUSH_END
#else
#define FLUSH_BEGIN(mm) if ((mm)->context != NO_CONTEXT) {
#define FLUSH_END       }
#endif

int flush_page_for_dma_global = 1;

char *srmmu_name;

ctxd_t *srmmu_ctx_table_phys;
static ctxd_t *srmmu_context_table;

int viking_mxcc_present;
static DEFINE_SPINLOCK(srmmu_context_spinlock);

static int is_hypersparc;

static int srmmu_cache_pagetables;

/* these will be initialized in srmmu_nocache_calcsize() */
static unsigned long srmmu_nocache_size;
static unsigned long srmmu_nocache_end;

/* 1 bit <=> 256 bytes of nocache <=> 64 PTEs */
#define SRMMU_NOCACHE_BITMAP_SHIFT (PAGE_SHIFT - 4)

/* The context table is a nocache user with the biggest alignment needs. */
#define SRMMU_NOCACHE_ALIGN_MAX (sizeof(ctxd_t)*SRMMU_MAX_CONTEXTS)

void *srmmu_nocache_pool;
void *srmmu_nocache_bitmap;
static struct bit_map srmmu_nocache_map;

static inline int srmmu_pmd_none(pmd_t pmd)
{ return !(pmd_val(pmd) & 0xFFFFFFF); }

/* XXX should we hyper_flush_whole_icache here - Anton */
static inline void srmmu_ctxd_set(ctxd_t *ctxp, pgd_t *pgdp)
{ set_pte((pte_t *)ctxp, (SRMMU_ET_PTD | (__nocache_pa((unsigned long) pgdp) >> 4))); }

void pmd_set(pmd_t *pmdp, pte_t *ptep)
{
        unsigned long ptp;      /* Physical address, shifted right by 4 */
        int i;

        ptp = __nocache_pa((unsigned long) ptep) >> 4;
        for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) {
                set_pte((pte_t *)&pmdp->pmdv[i], SRMMU_ET_PTD | ptp);
                ptp += (SRMMU_REAL_PTRS_PER_PTE*sizeof(pte_t) >> 4);
        }
}

void pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *ptep)
{
        unsigned long ptp;      /* Physical address, shifted right by 4 */
        int i;

        ptp = page_to_pfn(ptep) << (PAGE_SHIFT-4);      /* watch for overflow */
        for (i = 0; i < PTRS_PER_PTE/SRMMU_REAL_PTRS_PER_PTE; i++) {
                set_pte((pte_t *)&pmdp->pmdv[i], SRMMU_ET_PTD | ptp);
                ptp += (SRMMU_REAL_PTRS_PER_PTE*sizeof(pte_t) >> 4);
        }
}

/* Find an entry in the third-level page table.. */ 
pte_t *pte_offset_kernel(pmd_t * dir, unsigned long address)
{
        void *pte;

        pte = __nocache_va((dir->pmdv[0] & SRMMU_PTD_PMASK) << 4);
        return (pte_t *) pte +
            ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
}

/*
 * size: bytes to allocate in the nocache area.
 * align: bytes, number to align at.
 * Returns the virtual address of the allocated area.
 */
static unsigned long __srmmu_get_nocache(int size, int align)
{
        int offset;

        if (size < SRMMU_NOCACHE_BITMAP_SHIFT) {
                printk("Size 0x%x too small for nocache request\n", size);
                size = SRMMU_NOCACHE_BITMAP_SHIFT;
        }
        if (size & (SRMMU_NOCACHE_BITMAP_SHIFT-1)) {
                printk("Size 0x%x unaligned int nocache request\n", size);
                size += SRMMU_NOCACHE_BITMAP_SHIFT-1;
        }
        BUG_ON(align > SRMMU_NOCACHE_ALIGN_MAX);

        offset = bit_map_string_get(&srmmu_nocache_map,
                                        size >> SRMMU_NOCACHE_BITMAP_SHIFT,
                                        align >> SRMMU_NOCACHE_BITMAP_SHIFT);
        if (offset == -1) {
                printk("srmmu: out of nocache %d: %d/%d\n",
                    size, (int) srmmu_nocache_size,
                    srmmu_nocache_map.used << SRMMU_NOCACHE_BITMAP_SHIFT);
                return 0;
        }

        return (SRMMU_NOCACHE_VADDR + (offset << SRMMU_NOCACHE_BITMAP_SHIFT));
}

unsigned long srmmu_get_nocache(int size, int align)
{
        unsigned long tmp;

        tmp = __srmmu_get_nocache(size, align);

        if (tmp)
                memset((void *)tmp, 0, size);

        return tmp;
}

void srmmu_free_nocache(unsigned long vaddr, int size)
{
        int offset;

        if (vaddr < SRMMU_NOCACHE_VADDR) {
                printk("Vaddr %lx is smaller than nocache base 0x%lx\n",
                    vaddr, (unsigned long)SRMMU_NOCACHE_VADDR);
                BUG();
        }
        if (vaddr+size > srmmu_nocache_end) {
                printk("Vaddr %lx is bigger than nocache end 0x%lx\n",
                    vaddr, srmmu_nocache_end);
                BUG();
        }
        if (!is_power_of_2(size)) {
                printk("Size 0x%x is not a power of 2\n", size);
                BUG();
        }
        if (size < SRMMU_NOCACHE_BITMAP_SHIFT) {
                printk("Size 0x%x is too small\n", size);
                BUG();
        }
        if (vaddr & (size-1)) {
                printk("Vaddr %lx is not aligned to size 0x%x\n", vaddr, size);
                BUG();
        }

        offset = (vaddr - SRMMU_NOCACHE_VADDR) >> SRMMU_NOCACHE_BITMAP_SHIFT;
        size = size >> SRMMU_NOCACHE_BITMAP_SHIFT;

        bit_map_clear(&srmmu_nocache_map, offset, size);
}

static void srmmu_early_allocate_ptable_skeleton(unsigned long start,
                                                 unsigned long end);

extern unsigned long probe_memory(void);        /* in fault.c */

/*
 * Reserve nocache dynamically proportionally to the amount of
 * system RAM. -- Tomas Szepe <szepe@pinerecords.com>, June 2002
 */
static void srmmu_nocache_calcsize(void)
{
        unsigned long sysmemavail = probe_memory() / 1024;
        int srmmu_nocache_npages;

        srmmu_nocache_npages =
                sysmemavail / SRMMU_NOCACHE_ALCRATIO / 1024 * 256;

 /* P3 XXX The 4x overuse: corroborated by /proc/meminfo. */
        // if (srmmu_nocache_npages < 256) srmmu_nocache_npages = 256;
        if (srmmu_nocache_npages < SRMMU_MIN_NOCACHE_PAGES)
                srmmu_nocache_npages = SRMMU_MIN_NOCACHE_PAGES;

        /* anything above 1280 blows up */
        if (srmmu_nocache_npages > SRMMU_MAX_NOCACHE_PAGES)
                srmmu_nocache_npages = SRMMU_MAX_NOCACHE_PAGES;

        srmmu_nocache_size = srmmu_nocache_npages * PAGE_SIZE;
        srmmu_nocache_end = SRMMU_NOCACHE_VADDR + srmmu_nocache_size;
}

static void __init srmmu_nocache_init(void)
{
        unsigned int bitmap_bits;
        pgd_t *pgd;
        pmd_t *pmd;
        pte_t *pte;
        unsigned long paddr, vaddr;
        unsigned long pteval;

        bitmap_bits = srmmu_nocache_size >> SRMMU_NOCACHE_BITMAP_SHIFT;

        srmmu_nocache_pool = __alloc_bootmem(srmmu_nocache_size,
                SRMMU_NOCACHE_ALIGN_MAX, 0UL);
        memset(srmmu_nocache_pool, 0, srmmu_nocache_size);

        srmmu_nocache_bitmap = __alloc_bootmem(bitmap_bits >> 3, SMP_CACHE_BYTES, 0UL);
        bit_map_init(&srmmu_nocache_map, srmmu_nocache_bitmap, bitmap_bits);

        srmmu_swapper_pg_dir = (pgd_t *)__srmmu_get_nocache(SRMMU_PGD_TABLE_SIZE, SRMMU_PGD_TABLE_SIZE);
        memset(__nocache_fix(srmmu_swapper_pg_dir), 0, SRMMU_PGD_TABLE_SIZE);
        init_mm.pgd = srmmu_swapper_pg_dir;

        srmmu_early_allocate_ptable_skeleton(SRMMU_NOCACHE_VADDR, srmmu_nocache_end);

        paddr = __pa((unsigned long)srmmu_nocache_pool);
        vaddr = SRMMU_NOCACHE_VADDR;

        while (vaddr < srmmu_nocache_end) {
                pgd = pgd_offset_k(vaddr);
                pmd = pmd_offset(__nocache_fix(pgd), vaddr);
                pte = pte_offset_kernel(__nocache_fix(pmd), vaddr);

                pteval = ((paddr >> 4) | SRMMU_ET_PTE | SRMMU_PRIV);

                if (srmmu_cache_pagetables)
                        pteval |= SRMMU_CACHE;

                set_pte(__nocache_fix(pte), __pte(pteval));

                vaddr += PAGE_SIZE;
                paddr += PAGE_SIZE;
        }

        flush_cache_all();
        flush_tlb_all();
}

pgd_t *get_pgd_fast(void)
{
        pgd_t *pgd = NULL;

        pgd = (pgd_t *)__srmmu_get_nocache(SRMMU_PGD_TABLE_SIZE, SRMMU_PGD_TABLE_SIZE);
        if (pgd) {
                pgd_t *init = pgd_offset_k(0);
                memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
                memcpy(pgd + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
                                                (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
        }

        return pgd;
}

/*
 * Hardware needs alignment to 256 only, but we align to whole page size
 * to reduce fragmentation problems due to the buddy principle.
 * XXX Provide actual fragmentation statistics in /proc.
 *
 * Alignments up to the page size are the same for physical and virtual
 * addresses of the nocache area.
 */
pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
        unsigned long pte;
        struct page *page;

        if ((pte = (unsigned long)pte_alloc_one_kernel(mm, address)) == 0)
                return NULL;
        page = pfn_to_page( __nocache_pa(pte) >> PAGE_SHIFT );
        pgtable_page_ctor(page);
        return page;
}

void pte_free(struct mm_struct *mm, pgtable_t pte)
{
        unsigned long p;

        pgtable_page_dtor(pte);
        p = (unsigned long)page_address(pte);   /* Cached address (for test) */
        if (p == 0)
                BUG();
        p = page_to_pfn(pte) << PAGE_SHIFT;     /* Physical address */
        p = (unsigned long) __nocache_va(p);    /* Nocached virtual */
        srmmu_free_nocache(p, PTE_SIZE);
}

/*
 */
static inline void alloc_context(struct mm_struct *old_mm, struct mm_struct *mm)
{
        struct ctx_list *ctxp;

        ctxp = ctx_free.next;
        if(ctxp != &ctx_free) {
                remove_from_ctx_list(ctxp);
                add_to_used_ctxlist(ctxp);
                mm->context = ctxp->ctx_number;
                ctxp->ctx_mm = mm;
                return;
        }
        ctxp = ctx_used.next;
        if(ctxp->ctx_mm == old_mm)
                ctxp = ctxp->next;
        if(ctxp == &ctx_used)
                panic("out of mmu contexts");
        flush_cache_mm(ctxp->ctx_mm);
        flush_tlb_mm(ctxp->ctx_mm);
        remove_from_ctx_list(ctxp);
        add_to_used_ctxlist(ctxp);
        ctxp->ctx_mm->context = NO_CONTEXT;
        ctxp->ctx_mm = mm;
        mm->context = ctxp->ctx_number;
}

static inline void free_context(int context)
{
        struct ctx_list *ctx_old;

        ctx_old = ctx_list_pool + context;
        remove_from_ctx_list(ctx_old);
        add_to_free_ctxlist(ctx_old);
}


void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm,
               struct task_struct *tsk)
{
        if(mm->context == NO_CONTEXT) {
                spin_lock(&srmmu_context_spinlock);
                alloc_context(old_mm, mm);
                spin_unlock(&srmmu_context_spinlock);
                srmmu_ctxd_set(&srmmu_context_table[mm->context], mm->pgd);
        }

        if (sparc_cpu_model == sparc_leon)
                leon_switch_mm();

        if (is_hypersparc)
                hyper_flush_whole_icache();

        srmmu_set_context(mm->context);
}

/* Low level IO area allocation on the SRMMU. */
static inline void srmmu_mapioaddr(unsigned long physaddr,
    unsigned long virt_addr, int bus_type)
{
        pgd_t *pgdp;
        pmd_t *pmdp;
        pte_t *ptep;
        unsigned long tmp;

        physaddr &= PAGE_MASK;
        pgdp = pgd_offset_k(virt_addr);
        pmdp = pmd_offset(pgdp, virt_addr);
        ptep = pte_offset_kernel(pmdp, virt_addr);
        tmp = (physaddr >> 4) | SRMMU_ET_PTE;

        /*
         * I need to test whether this is consistent over all
         * sun4m's.  The bus_type represents the upper 4 bits of
         * 36-bit physical address on the I/O space lines...
         */
        tmp |= (bus_type << 28);
        tmp |= SRMMU_PRIV;
        __flush_page_to_ram(virt_addr);
        set_pte(ptep, __pte(tmp));
}

void srmmu_mapiorange(unsigned int bus, unsigned long xpa,
                      unsigned long xva, unsigned int len)
{
        while (len != 0) {
                len -= PAGE_SIZE;
                srmmu_mapioaddr(xpa, xva, bus);
                xva += PAGE_SIZE;
                xpa += PAGE_SIZE;
        }
        flush_tlb_all();
}

static inline void srmmu_unmapioaddr(unsigned long virt_addr)
{
        pgd_t *pgdp;
        pmd_t *pmdp;
        pte_t *ptep;

        pgdp = pgd_offset_k(virt_addr);
        pmdp = pmd_offset(pgdp, virt_addr);
        ptep = pte_offset_kernel(pmdp, virt_addr);

        /* No need to flush uncacheable page. */
        __pte_clear(ptep);
}

void srmmu_unmapiorange(unsigned long virt_addr, unsigned int len)
{
        while (len != 0) {
                len -= PAGE_SIZE;
                srmmu_unmapioaddr(virt_addr);
                virt_addr += PAGE_SIZE;
        }
        flush_tlb_all();
}

/* tsunami.S */
extern void tsunami_flush_cache_all(void);
extern void tsunami_flush_cache_mm(struct mm_struct *mm);
extern void tsunami_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void tsunami_flush_cache_page(struct vm_area_struct *vma, unsigned long page);
extern void tsunami_flush_page_to_ram(unsigned long page);
extern void tsunami_flush_page_for_dma(unsigned long page);
extern void tsunami_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr);
extern void tsunami_flush_tlb_all(void);
extern void tsunami_flush_tlb_mm(struct mm_struct *mm);
extern void tsunami_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void tsunami_flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
extern void tsunami_setup_blockops(void);

/* swift.S */
extern void swift_flush_cache_all(void);
extern void swift_flush_cache_mm(struct mm_struct *mm);
extern void swift_flush_cache_range(struct vm_area_struct *vma,
                                    unsigned long start, unsigned long end);
extern void swift_flush_cache_page(struct vm_area_struct *vma, unsigned long page);
extern void swift_flush_page_to_ram(unsigned long page);
extern void swift_flush_page_for_dma(unsigned long page);
extern void swift_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr);
extern void swift_flush_tlb_all(void);
extern void swift_flush_tlb_mm(struct mm_struct *mm);
extern void swift_flush_tlb_range(struct vm_area_struct *vma,
                                  unsigned long start, unsigned long end);
extern void swift_flush_tlb_page(struct vm_area_struct *vma, unsigned long page);

#if 0  /* P3: deadwood to debug precise flushes on Swift. */
void swift_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
        int cctx, ctx1;

        page &= PAGE_MASK;
        if ((ctx1 = vma->vm_mm->context) != -1) {
                cctx = srmmu_get_context();
/* Is context # ever different from current context? P3 */
                if (cctx != ctx1) {
                        printk("flush ctx %02x curr %02x\n", ctx1, cctx);
                        srmmu_set_context(ctx1);
                        swift_flush_page(page);
                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                        "r" (page), "i" (ASI_M_FLUSH_PROBE));
                        srmmu_set_context(cctx);
                } else {
                         /* Rm. prot. bits from virt. c. */
                        /* swift_flush_cache_all(); */
                        /* swift_flush_cache_page(vma, page); */
                        swift_flush_page(page);

                        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : :
                                "r" (page), "i" (ASI_M_FLUSH_PROBE));
                        /* same as above: srmmu_flush_tlb_page() */
                }
        }
}
#endif

/*
 * The following are all MBUS based SRMMU modules, and therefore could
 * be found in a multiprocessor configuration.  On the whole, these
 * chips seems to be much more touchy about DVMA and page tables
 * with respect to cache coherency.
 */

/* viking.S */
extern void viking_flush_cache_all(void);
extern void viking_flush_cache_mm(struct mm_struct *mm);
extern void viking_flush_cache_range(struct vm_area_struct *vma, unsigned long start,
                                     unsigned long end);
extern void viking_flush_cache_page(struct vm_area_struct *vma, unsigned long page);
extern void viking_flush_page_to_ram(unsigned long page);
extern void viking_flush_page_for_dma(unsigned long page);
extern void viking_flush_sig_insns(struct mm_struct *mm, unsigned long addr);
extern void viking_flush_page(unsigned long page);
extern void viking_mxcc_flush_page(unsigned long page);
extern void viking_flush_tlb_all(void);
extern void viking_flush_tlb_mm(struct mm_struct *mm);
extern void viking_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
                                   unsigned long end);
extern void viking_flush_tlb_page(struct vm_area_struct *vma,
                                  unsigned long page);
extern void sun4dsmp_flush_tlb_all(void);
extern void sun4dsmp_flush_tlb_mm(struct mm_struct *mm);
extern void sun4dsmp_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
                                   unsigned long end);
extern void sun4dsmp_flush_tlb_page(struct vm_area_struct *vma,
                                  unsigned long page);

/* hypersparc.S */
extern void hypersparc_flush_cache_all(void);
extern void hypersparc_flush_cache_mm(struct mm_struct *mm);
extern void hypersparc_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void hypersparc_flush_cache_page(struct vm_area_struct *vma, unsigned long page);
extern void hypersparc_flush_page_to_ram(unsigned long page);
extern void hypersparc_flush_page_for_dma(unsigned long page);
extern void hypersparc_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr);
extern void hypersparc_flush_tlb_all(void);
extern void hypersparc_flush_tlb_mm(struct mm_struct *mm);
extern void hypersparc_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void hypersparc_flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
extern void hypersparc_setup_blockops(void);

/*
 * NOTE: All of this startup code assumes the low 16mb (approx.) of
 *       kernel mappings are done with one single contiguous chunk of
 *       ram.  On small ram machines (classics mainly) we only get
 *       around 8mb mapped for us.
 */

static void __init early_pgtable_allocfail(char *type)
{
        prom_printf("inherit_prom_mappings: Cannot alloc kernel %s.\n", type);
        prom_halt();
}

static void __init srmmu_early_allocate_ptable_skeleton(unsigned long start,
                                                        unsigned long end)
{
        pgd_t *pgdp;
        pmd_t *pmdp;
        pte_t *ptep;

        while(start < end) {
                pgdp = pgd_offset_k(start);
                if (pgd_none(*(pgd_t *)__nocache_fix(pgdp))) {
                        pmdp = (pmd_t *) __srmmu_get_nocache(
                            SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
                        if (pmdp == NULL)
                                early_pgtable_allocfail("pmd");
                        memset(__nocache_fix(pmdp), 0, SRMMU_PMD_TABLE_SIZE);
                        pgd_set(__nocache_fix(pgdp), pmdp);
                }
                pmdp = pmd_offset(__nocache_fix(pgdp), start);
                if(srmmu_pmd_none(*(pmd_t *)__nocache_fix(pmdp))) {
                        ptep = (pte_t *)__srmmu_get_nocache(PTE_SIZE, PTE_SIZE);
                        if (ptep == NULL)
                                early_pgtable_allocfail("pte");
                        memset(__nocache_fix(ptep), 0, PTE_SIZE);
                        pmd_set(__nocache_fix(pmdp), ptep);
                }
                if (start > (0xffffffffUL - PMD_SIZE))
                        break;
                start = (start + PMD_SIZE) & PMD_MASK;
        }
}

static void __init srmmu_allocate_ptable_skeleton(unsigned long start,
                                                  unsigned long end)
{
        pgd_t *pgdp;
        pmd_t *pmdp;
        pte_t *ptep;

        while(start < end) {
                pgdp = pgd_offset_k(start);
                if (pgd_none(*pgdp)) {
                        pmdp = (pmd_t *)__srmmu_get_nocache(SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
                        if (pmdp == NULL)
                                early_pgtable_allocfail("pmd");
                        memset(pmdp, 0, SRMMU_PMD_TABLE_SIZE);
                        pgd_set(pgdp, pmdp);
                }
                pmdp = pmd_offset(pgdp, start);
                if(srmmu_pmd_none(*pmdp)) {
                        ptep = (pte_t *) __srmmu_get_nocache(PTE_SIZE,
                                                             PTE_SIZE);
                        if (ptep == NULL)
                                early_pgtable_allocfail("pte");
                        memset(ptep, 0, PTE_SIZE);
                        pmd_set(pmdp, ptep);
                }
                if (start > (0xffffffffUL - PMD_SIZE))
                        break;
                start = (start + PMD_SIZE) & PMD_MASK;
        }
}

/*
 * This is much cleaner than poking around physical address space
 * looking at the prom's page table directly which is what most
 * other OS's do.  Yuck... this is much better.
 */
static void __init srmmu_inherit_prom_mappings(unsigned long start,
                                               unsigned long end)
{
        pgd_t *pgdp;
        pmd_t *pmdp;
        pte_t *ptep;
        int what = 0; /* 0 = normal-pte, 1 = pmd-level pte, 2 = pgd-level pte */
        unsigned long prompte;

        while(start <= end) {
                if (start == 0)
                        break; /* probably wrap around */
                if(start == 0xfef00000)
                        start = KADB_DEBUGGER_BEGVM;
                if(!(prompte = srmmu_hwprobe(start))) {
                        start += PAGE_SIZE;
                        continue;
                }
    
                /* A red snapper, see what it really is. */
                what = 0;
    
                if(!(start & ~(SRMMU_REAL_PMD_MASK))) {
                        if(srmmu_hwprobe((start-PAGE_SIZE) + SRMMU_REAL_PMD_SIZE) == prompte)
                                what = 1;
                }
    
                if(!(start & ~(SRMMU_PGDIR_MASK))) {
                        if(srmmu_hwprobe((start-PAGE_SIZE) + SRMMU_PGDIR_SIZE) ==
                           prompte)
                                what = 2;
                }
    
                pgdp = pgd_offset_k(start);
                if(what == 2) {
                        *(pgd_t *)__nocache_fix(pgdp) = __pgd(prompte);
                        start += SRMMU_PGDIR_SIZE;
                        continue;
                }
                if (pgd_none(*(pgd_t *)__nocache_fix(pgdp))) {
                        pmdp = (pmd_t *)__srmmu_get_nocache(SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
                        if (pmdp == NULL)
                                early_pgtable_allocfail("pmd");
                        memset(__nocache_fix(pmdp), 0, SRMMU_PMD_TABLE_SIZE);
                        pgd_set(__nocache_fix(pgdp), pmdp);
                }
                pmdp = pmd_offset(__nocache_fix(pgdp), start);
                if(srmmu_pmd_none(*(pmd_t *)__nocache_fix(pmdp))) {
                        ptep = (pte_t *) __srmmu_get_nocache(PTE_SIZE,
                                                             PTE_SIZE);
                        if (ptep == NULL)
                                early_pgtable_allocfail("pte");
                        memset(__nocache_fix(ptep), 0, PTE_SIZE);
                        pmd_set(__nocache_fix(pmdp), ptep);
                }
                if(what == 1) {
                        /*
                         * We bend the rule where all 16 PTPs in a pmd_t point
                         * inside the same PTE page, and we leak a perfectly
                         * good hardware PTE piece. Alternatives seem worse.
                         */
                        unsigned int x; /* Index of HW PMD in soft cluster */
                        x = (start >> PMD_SHIFT) & 15;
                        *(unsigned long *)__nocache_fix(&pmdp->pmdv[x]) = prompte;
                        start += SRMMU_REAL_PMD_SIZE;
                        continue;
                }
                ptep = pte_offset_kernel(__nocache_fix(pmdp), start);
                *(pte_t *)__nocache_fix(ptep) = __pte(prompte);
                start += PAGE_SIZE;
        }
}

#define KERNEL_PTE(page_shifted) ((page_shifted)|SRMMU_CACHE|SRMMU_PRIV|SRMMU_VALID)

/* Create a third-level SRMMU 16MB page mapping. */
static void __init do_large_mapping(unsigned long vaddr, unsigned long phys_base)
{
        pgd_t *pgdp = pgd_offset_k(vaddr);
        unsigned long big_pte;

        big_pte = KERNEL_PTE(phys_base >> 4);
        *(pgd_t *)__nocache_fix(pgdp) = __pgd(big_pte);
}

/* Map sp_bank entry SP_ENTRY, starting at virtual address VBASE. */
static unsigned long __init map_spbank(unsigned long vbase, int sp_entry)
{
        unsigned long pstart = (sp_banks[sp_entry].base_addr & SRMMU_PGDIR_MASK);
        unsigned long vstart = (vbase & SRMMU_PGDIR_MASK);
        unsigned long vend = SRMMU_PGDIR_ALIGN(vbase + sp_banks[sp_entry].num_bytes);
        /* Map "low" memory only */
        const unsigned long min_vaddr = PAGE_OFFSET;
        const unsigned long max_vaddr = PAGE_OFFSET + SRMMU_MAXMEM;

        if (vstart < min_vaddr || vstart >= max_vaddr)
                return vstart;
        
        if (vend > max_vaddr || vend < min_vaddr)
                vend = max_vaddr;

        while(vstart < vend) {
                do_large_mapping(vstart, pstart);
                vstart += SRMMU_PGDIR_SIZE; pstart += SRMMU_PGDIR_SIZE;
        }
        return vstart;
}

static inline void map_kernel(void)
{
        int i;

        if (phys_base > 0) {
                do_large_mapping(PAGE_OFFSET, phys_base);
        }

        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
                map_spbank((unsigned long)__va(sp_banks[i].base_addr), i);
        }
}

/* Paging initialization on the Sparc Reference MMU. */
extern void sparc_context_init(int);

void (*poke_srmmu)(void) __cpuinitdata = NULL;

extern unsigned long bootmem_init(unsigned long *pages_avail);

void __init srmmu_paging_init(void)
{
        int i;
        phandle cpunode;
        char node_str[128];
        pgd_t *pgd;
        pmd_t *pmd;
        pte_t *pte;
        unsigned long pages_avail;

        sparc_iomap.start = SUN4M_IOBASE_VADDR; /* 16MB of IOSPACE on all sun4m's. */

        if (sparc_cpu_model == sun4d)
                num_contexts = 65536; /* We know it is Viking */
        else {
                /* Find the number of contexts on the srmmu. */
                cpunode = prom_getchild(prom_root_node);
                num_contexts = 0;
                while(cpunode != 0) {
                        prom_getstring(cpunode, "device_type", node_str, sizeof(node_str));
                        if(!strcmp(node_str, "cpu")) {
                                num_contexts = prom_getintdefault(cpunode, "mmu-nctx", 0x8);
                                break;
                        }
                        cpunode = prom_getsibling(cpunode);
                }
        }

        if(!num_contexts) {
                prom_printf("Something wrong, can't find cpu node in paging_init.\n");
                prom_halt();
        }

        pages_avail = 0;
        last_valid_pfn = bootmem_init(&pages_avail);

        srmmu_nocache_calcsize();
        srmmu_nocache_init();
        srmmu_inherit_prom_mappings(0xfe400000,(LINUX_OPPROM_ENDVM-PAGE_SIZE));
        map_kernel();

        /* ctx table has to be physically aligned to its size */
        srmmu_context_table = (ctxd_t *)__srmmu_get_nocache(num_contexts*sizeof(ctxd_t), num_contexts*sizeof(ctxd_t));
        srmmu_ctx_table_phys = (ctxd_t *)__nocache_pa((unsigned long)srmmu_context_table);

        for(i = 0; i < num_contexts; i++)
                srmmu_ctxd_set((ctxd_t *)__nocache_fix(&srmmu_context_table[i]), srmmu_swapper_pg_dir);

        flush_cache_all();
        srmmu_set_ctable_ptr((unsigned long)srmmu_ctx_table_phys);
#ifdef CONFIG_SMP
        /* Stop from hanging here... */
        local_ops->tlb_all();
#else
        flush_tlb_all();
#endif
        poke_srmmu();

        srmmu_allocate_ptable_skeleton(sparc_iomap.start, IOBASE_END);
        srmmu_allocate_ptable_skeleton(DVMA_VADDR, DVMA_END);

        srmmu_allocate_ptable_skeleton(
                __fix_to_virt(__end_of_fixed_addresses - 1), FIXADDR_TOP);
        srmmu_allocate_ptable_skeleton(PKMAP_BASE, PKMAP_END);

        pgd = pgd_offset_k(PKMAP_BASE);
        pmd = pmd_offset(pgd, PKMAP_BASE);
        pte = pte_offset_kernel(pmd, PKMAP_BASE);
        pkmap_page_table = pte;

        flush_cache_all();
        flush_tlb_all();

        sparc_context_init(num_contexts);

        kmap_init();

        {
                unsigned long zones_size[MAX_NR_ZONES];
                unsigned long zholes_size[MAX_NR_ZONES];
                unsigned long npages;
                int znum;

                for (znum = 0; znum < MAX_NR_ZONES; znum++)
                        zones_size[znum] = zholes_size[znum] = 0;

                npages = max_low_pfn - pfn_base;

                zones_size[ZONE_DMA] = npages;
                zholes_size[ZONE_DMA] = npages - pages_avail;

                npages = highend_pfn - max_low_pfn;
                zones_size[ZONE_HIGHMEM] = npages;
                zholes_size[ZONE_HIGHMEM] = npages - calc_highpages();

                free_area_init_node(0, zones_size, pfn_base, zholes_size);
        }
}

void mmu_info(struct seq_file *m)
{
        seq_printf(m, 
                   "MMU type\t: %s\n"
                   "contexts\t: %d\n"
                   "nocache total\t: %ld\n"
                   "nocache used\t: %d\n",
                   srmmu_name,
                   num_contexts,
                   srmmu_nocache_size,
                   srmmu_nocache_map.used << SRMMU_NOCACHE_BITMAP_SHIFT);
}

void destroy_context(struct mm_struct *mm)
{

        if(mm->context != NO_CONTEXT) {
                flush_cache_mm(mm);
                srmmu_ctxd_set(&srmmu_context_table[mm->context], srmmu_swapper_pg_dir);
                flush_tlb_mm(mm);
                spin_lock(&srmmu_context_spinlock);
                free_context(mm->context);
                spin_unlock(&srmmu_context_spinlock);
                mm->context = NO_CONTEXT;
        }
}

/* Init various srmmu chip types. */
static void __init srmmu_is_bad(void)
{
        prom_printf("Could not determine SRMMU chip type.\n");
        prom_halt();
}

static void __init init_vac_layout(void)
{
        phandle nd;
        int cache_lines;
        char node_str[128];
#ifdef CONFIG_SMP
        int cpu = 0;
        unsigned long max_size = 0;
        unsigned long min_line_size = 0x10000000;
#endif

        nd = prom_getchild(prom_root_node);
        while((nd = prom_getsibling(nd)) != 0) {
                prom_getstring(nd, "device_type", node_str, sizeof(node_str));
                if(!strcmp(node_str, "cpu")) {
                        vac_line_size = prom_getint(nd, "cache-line-size");
                        if (vac_line_size == -1) {
                                prom_printf("can't determine cache-line-size, "
                                            "halting.\n");
                                prom_halt();
                        }
                        cache_lines = prom_getint(nd, "cache-nlines");
                        if (cache_lines == -1) {
                                prom_printf("can't determine cache-nlines, halting.\n");
                                prom_halt();
                        }

                        vac_cache_size = cache_lines * vac_line_size;
#ifdef CONFIG_SMP
                        if(vac_cache_size > max_size)
                                max_size = vac_cache_size;
                        if(vac_line_size < min_line_size)
                                min_line_size = vac_line_size;
                        //FIXME: cpus not contiguous!!
                        cpu++;
                        if (cpu >= nr_cpu_ids || !cpu_online(cpu))
                                break;
#else
                        break;
#endif
                }
        }
        if(nd == 0) {
                prom_printf("No CPU nodes found, halting.\n");
                prom_halt();
        }
#ifdef CONFIG_SMP
        vac_cache_size = max_size;
        vac_line_size = min_line_size;
#endif
        printk("SRMMU: Using VAC size of %d bytes, line size %d bytes.\n",
               (int)vac_cache_size, (int)vac_line_size);
}

static void __cpuinit poke_hypersparc(void)
{
        volatile unsigned long clear;
        unsigned long mreg = srmmu_get_mmureg();

        hyper_flush_unconditional_combined();

        mreg &= ~(HYPERSPARC_CWENABLE);
        mreg |= (HYPERSPARC_CENABLE | HYPERSPARC_WBENABLE);
        mreg |= (HYPERSPARC_CMODE);

        srmmu_set_mmureg(mreg);

#if 0 /* XXX I think this is bad news... -DaveM */
        hyper_clear_all_tags();
#endif

        put_ross_icr(HYPERSPARC_ICCR_FTD | HYPERSPARC_ICCR_ICE);
        hyper_flush_whole_icache();
        clear = srmmu_get_faddr();
        clear = srmmu_get_fstatus();
}

static const struct sparc32_cachetlb_ops hypersparc_ops = {
        .cache_all      = hypersparc_flush_cache_all,
        .cache_mm       = hypersparc_flush_cache_mm,
        .cache_page     = hypersparc_flush_cache_page,
        .cache_range    = hypersparc_flush_cache_range,
        .tlb_all        = hypersparc_flush_tlb_all,
        .tlb_mm         = hypersparc_flush_tlb_mm,
        .tlb_page       = hypersparc_flush_tlb_page,
        .tlb_range      = hypersparc_flush_tlb_range,
        .page_to_ram    = hypersparc_flush_page_to_ram,
        .sig_insns      = hypersparc_flush_sig_insns,
        .page_for_dma   = hypersparc_flush_page_for_dma,
};

static void __init init_hypersparc(void)
{
        srmmu_name = "ROSS HyperSparc";
        srmmu_modtype = HyperSparc;

        init_vac_layout();

        is_hypersparc = 1;
        sparc32_cachetlb_ops = &hypersparc_ops;

        poke_srmmu = poke_hypersparc;

        hypersparc_setup_blockops();
}

static void __cpuinit poke_swift(void)
{
        unsigned long mreg;

        /* Clear any crap from the cache or else... */
        swift_flush_cache_all();

        /* Enable I & D caches */
        mreg = srmmu_get_mmureg();
        mreg |= (SWIFT_IE | SWIFT_DE);
        /*
         * The Swift branch folding logic is completely broken.  At
         * trap time, if things are just right, if can mistakenly
         * think that a trap is coming from kernel mode when in fact
         * it is coming from user mode (it mis-executes the branch in
         * the trap code).  So you see things like crashme completely
         * hosing your machine which is completely unacceptable.  Turn
         * this shit off... nice job Fujitsu.
         */
        mreg &= ~(SWIFT_BF);
        srmmu_set_mmureg(mreg);
}

static const struct sparc32_cachetlb_ops swift_ops = {
        .cache_all      = swift_flush_cache_all,
        .cache_mm       = swift_flush_cache_mm,
        .cache_page     = swift_flush_cache_page,
        .cache_range    = swift_flush_cache_range,
        .tlb_all        = swift_flush_tlb_all,
        .tlb_mm         = swift_flush_tlb_mm,
        .tlb_page       = swift_flush_tlb_page,
        .tlb_range      = swift_flush_tlb_range,
        .page_to_ram    = swift_flush_page_to_ram,
        .sig_insns      = swift_flush_sig_insns,
        .page_for_dma   = swift_flush_page_for_dma,
};

#define SWIFT_MASKID_ADDR  0x10003018
static void __init init_swift(void)
{
        unsigned long swift_rev;

        __asm__ __volatile__("lda [%1] %2, %0\n\t"
                             "srl %0, 0x18, %0\n\t" :
                             "=r" (swift_rev) :
                             "r" (SWIFT_MASKID_ADDR), "i" (ASI_M_BYPASS));
        srmmu_name = "Fujitsu Swift";
        switch(swift_rev) {
        case 0x11:
        case 0x20:
        case 0x23:
        case 0x30:
                srmmu_modtype = Swift_lots_o_bugs;
                hwbug_bitmask |= (HWBUG_KERN_ACCBROKEN | HWBUG_KERN_CBITBROKEN);
                /*
                 * Gee george, I wonder why Sun is so hush hush about
                 * this hardware bug... really braindamage stuff going
                 * on here.  However I think we can find a way to avoid
                 * all of the workaround overhead under Linux.  Basically,
                 * any page fault can cause kernel pages to become user
                 * accessible (the mmu gets confused and clears some of
                 * the ACC bits in kernel ptes).  Aha, sounds pretty
                 * horrible eh?  But wait, after extensive testing it appears
                 * that if you use pgd_t level large kernel pte's (like the
                 * 4MB pages on the Pentium) the bug does not get tripped
                 * at all.  This avoids almost all of the major overhead.
                 * Welcome to a world where your vendor tells you to,
                 * "apply this kernel patch" instead of "sorry for the
                 * broken hardware, send it back and we'll give you
                 * properly functioning parts"
                 */
                break;
        case 0x25:
        case 0x31:
                srmmu_modtype = Swift_bad_c;
                hwbug_bitmask |= HWBUG_KERN_CBITBROKEN;
                /*
                 * You see Sun allude to this hardware bug but never
                 * admit things directly, they'll say things like,
                 * "the Swift chip cache problems" or similar.
                 */
                break;
        default:
                srmmu_modtype = Swift_ok;
                break;
        }

        sparc32_cachetlb_ops = &swift_ops;
        flush_page_for_dma_global = 0;

        /*
         * Are you now convinced that the Swift is one of the
         * biggest VLSI abortions of all time?  Bravo Fujitsu!
         * Fujitsu, the !#?!%$'d up processor people.  I bet if
         * you examined the microcode of the Swift you'd find
         * XXX's all over the place.
         */
        poke_srmmu = poke_swift;
}

static void turbosparc_flush_cache_all(void)
{
        flush_user_windows();
        turbosparc_idflash_clear();
}

static void turbosparc_flush_cache_mm(struct mm_struct *mm)
{
        FLUSH_BEGIN(mm)
        flush_user_windows();
        turbosparc_idflash_clear();
        FLUSH_END
}

static void turbosparc_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
        FLUSH_BEGIN(vma->vm_mm)
        flush_user_windows();
        turbosparc_idflash_clear();
        FLUSH_END
}

static void turbosparc_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
{
        FLUSH_BEGIN(vma->vm_mm)
        flush_user_windows();
        if (vma->vm_flags & VM_EXEC)
                turbosparc_flush_icache();
        turbosparc_flush_dcache();
        FLUSH_END
}

/* TurboSparc is copy-back, if we turn it on, but this does not work. */
static void turbosparc_flush_page_to_ram(unsigned long page)
{
#ifdef TURBOSPARC_WRITEBACK
        volatile unsigned long clear;

        if (srmmu_hwprobe(page))
                turbosparc_flush_page_cache(page);
        clear = srmmu_get_fstatus();
#endif
}

static void turbosparc_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr)
{
}

static void turbosparc_flush_page_for_dma(unsigned long page)
{
        turbosparc_flush_dcache();
}

static void turbosparc_flush_tlb_all(void)
{
        srmmu_flush_whole_tlb();
}

static void turbosparc_flush_tlb_mm(struct mm_struct *mm)
{
        FLUSH_BEGIN(mm)
        srmmu_flush_whole_tlb();
        FLUSH_END
}

static void turbosparc_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
        FLUSH_BEGIN(vma->vm_mm)
        srmmu_flush_whole_tlb();
        FLUSH_END
}

static void turbosparc_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
        FLUSH_BEGIN(vma->vm_mm)
        srmmu_flush_whole_tlb();
        FLUSH_END
}


static void __cpuinit poke_turbosparc(void)
{
        unsigned long mreg = srmmu_get_mmureg();
        unsigned long ccreg;

        /* Clear any crap from the cache or else... */
        turbosparc_flush_cache_all();
        mreg &= ~(TURBOSPARC_ICENABLE | TURBOSPARC_DCENABLE); /* Temporarily disable I & D caches */
        mreg &= ~(TURBOSPARC_PCENABLE);         /* Don't check parity */
        srmmu_set_mmureg(mreg);
        
        ccreg = turbosparc_get_ccreg();

#ifdef TURBOSPARC_WRITEBACK
        ccreg |= (TURBOSPARC_SNENABLE);         /* Do DVMA snooping in Dcache */
        ccreg &= ~(TURBOSPARC_uS2 | TURBOSPARC_WTENABLE);
                        /* Write-back D-cache, emulate VLSI
                         * abortion number three, not number one */
#else
        /* For now let's play safe, optimize later */
        ccreg |= (TURBOSPARC_SNENABLE | TURBOSPARC_WTENABLE);
                        /* Do DVMA snooping in Dcache, Write-thru D-cache */
        ccreg &= ~(TURBOSPARC_uS2);
                        /* Emulate VLSI abortion number three, not number one */
#endif

        switch (ccreg & 7) {
        case 0: /* No SE cache */
        case 7: /* Test mode */
                break;
        default:
                ccreg |= (TURBOSPARC_SCENABLE);
        }
        turbosparc_set_ccreg (ccreg);

        mreg |= (TURBOSPARC_ICENABLE | TURBOSPARC_DCENABLE); /* I & D caches on */
        mreg |= (TURBOSPARC_ICSNOOP);           /* Icache snooping on */
        srmmu_set_mmureg(mreg);
}

static const struct sparc32_cachetlb_ops turbosparc_ops = {
        .cache_all      = turbosparc_flush_cache_all,
        .cache_mm       = turbosparc_flush_cache_mm,
        .cache_page     = turbosparc_flush_cache_page,
        .cache_range    = turbosparc_flush_cache_range,
        .tlb_all        = turbosparc_flush_tlb_all,
        .tlb_mm         = turbosparc_flush_tlb_mm,
        .tlb_page       = turbosparc_flush_tlb_page,
        .tlb_range      = turbosparc_flush_tlb_range,
        .page_to_ram    = turbosparc_flush_page_to_ram,
        .sig_insns      = turbosparc_flush_sig_insns,
        .page_for_dma   = turbosparc_flush_page_for_dma,
};

static void __init init_turbosparc(void)
{
        srmmu_name = "Fujitsu TurboSparc";
        srmmu_modtype = TurboSparc;
        sparc32_cachetlb_ops = &turbosparc_ops;
        poke_srmmu = poke_turbosparc;
}

static void __cpuinit poke_tsunami(void)
{
        unsigned long mreg = srmmu_get_mmureg();

        tsunami_flush_icache();
        tsunami_flush_dcache();
        mreg &= ~TSUNAMI_ITD;
        mreg |= (TSUNAMI_IENAB | TSUNAMI_DENAB);
        srmmu_set_mmureg(mreg);
}

static const struct sparc32_cachetlb_ops tsunami_ops = {
        .cache_all      = tsunami_flush_cache_all,
        .cache_mm       = tsunami_flush_cache_mm,
        .cache_page     = tsunami_flush_cache_page,
        .cache_range    = tsunami_flush_cache_range,
        .tlb_all        = tsunami_flush_tlb_all,
        .tlb_mm         = tsunami_flush_tlb_mm,
        .tlb_page       = tsunami_flush_tlb_page,
        .tlb_range      = tsunami_flush_tlb_range,
        .page_to_ram    = tsunami_flush_page_to_ram,
        .sig_insns      = tsunami_flush_sig_insns,
        .page_for_dma   = tsunami_flush_page_for_dma,
};

static void __init init_tsunami(void)
{
        /*
         * Tsunami's pretty sane, Sun and TI actually got it
         * somewhat right this time.  Fujitsu should have
         * taken some lessons from them.
         */

        srmmu_name = "TI Tsunami";
        srmmu_modtype = Tsunami;
        sparc32_cachetlb_ops = &tsunami_ops;
        poke_srmmu = poke_tsunami;

        tsunami_setup_blockops();
}

static void __cpuinit poke_viking(void)
{
        unsigned long mreg = srmmu_get_mmureg();
        static int smp_catch;

        if (viking_mxcc_present) {
                unsigned long mxcc_control = mxcc_get_creg();

                mxcc_control |= (MXCC_CTL_ECE | MXCC_CTL_PRE | MXCC_CTL_MCE);
                mxcc_control &= ~(MXCC_CTL_RRC);
                mxcc_set_creg(mxcc_control);

                /*
                 * We don't need memory parity checks.
                 * XXX This is a mess, have to dig out later. ecd.
                viking_mxcc_turn_off_parity(&mreg, &mxcc_control);
                 */

                /* We do cache ptables on MXCC. */
                mreg |= VIKING_TCENABLE;
        } else {
                unsigned long bpreg;

                mreg &= ~(VIKING_TCENABLE);
                if(smp_catch++) {
                        /* Must disable mixed-cmd mode here for other cpu's. */
                        bpreg = viking_get_bpreg();
                        bpreg &= ~(VIKING_ACTION_MIX);
                        viking_set_bpreg(bpreg);

                        /* Just in case PROM does something funny. */
                        msi_set_sync();
                }
        }

        mreg |= VIKING_SPENABLE;
        mreg |= (VIKING_ICENABLE | VIKING_DCENABLE);
        mreg |= VIKING_SBENABLE;
        mreg &= ~(VIKING_ACENABLE);
        srmmu_set_mmureg(mreg);
}

static struct sparc32_cachetlb_ops viking_ops = {
        .cache_all      = viking_flush_cache_all,
        .cache_mm       = viking_flush_cache_mm,
        .cache_page     = viking_flush_cache_page,
        .cache_range    = viking_flush_cache_range,
        .tlb_all        = viking_flush_tlb_all,
        .tlb_mm         = viking_flush_tlb_mm,
        .tlb_page       = viking_flush_tlb_page,
        .tlb_range      = viking_flush_tlb_range,
        .page_to_ram    = viking_flush_page_to_ram,
        .sig_insns      = viking_flush_sig_insns,
        .page_for_dma   = viking_flush_page_for_dma,
};

#ifdef CONFIG_SMP
/* On sun4d the cpu broadcasts local TLB flushes, so we can just
 * perform the local TLB flush and all the other cpus will see it.
 * But, unfortunately, there is a bug in the sun4d XBUS backplane
 * that requires that we add some synchronization to these flushes.
 *
 * The bug is that the fifo which keeps track of all the pending TLB
 * broadcasts in the system is an entry or two too small, so if we
 * have too many going at once we'll overflow that fifo and lose a TLB
 * flush resulting in corruption.
 *
 * Our workaround is to take a global spinlock around the TLB flushes,
 * which guarentees we won't ever have too many pending.  It's a big
 * hammer, but a semaphore like system to make sure we only have N TLB
 * flushes going at once will require SMP locking anyways so there's
 * no real value in trying any harder than this.
 */
static struct sparc32_cachetlb_ops viking_sun4d_smp_ops = {
        .cache_all      = viking_flush_cache_all,
        .cache_mm       = viking_flush_cache_mm,
        .cache_page     = viking_flush_cache_page,
        .cache_range    = viking_flush_cache_range,
        .tlb_all        = sun4dsmp_flush_tlb_all,
        .tlb_mm         = sun4dsmp_flush_tlb_mm,
        .tlb_page       = sun4dsmp_flush_tlb_page,
        .tlb_range      = sun4dsmp_flush_tlb_range,
        .page_to_ram    = viking_flush_page_to_ram,
        .sig_insns      = viking_flush_sig_insns,
        .page_for_dma   = viking_flush_page_for_dma,
};
#endif

static void __init init_viking(void)
{
        unsigned long mreg = srmmu_get_mmureg();

        /* Ahhh, the viking.  SRMMU VLSI abortion number two... */
        if(mreg & VIKING_MMODE) {
                srmmu_name = "TI Viking";
                viking_mxcc_present = 0;
                msi_set_sync();

                /*
                 * We need this to make sure old viking takes no hits
                 * on it's cache for dma snoops to workaround the
                 * "load from non-cacheable memory" interrupt bug.
                 * This is only necessary because of the new way in
                 * which we use the IOMMU.
                 */
                viking_ops.page_for_dma = viking_flush_page;
#ifdef CONFIG_SMP
                viking_sun4d_smp_ops.page_for_dma = viking_flush_page;
#endif
                flush_page_for_dma_global = 0;
        } else {
                srmmu_name = "TI Viking/MXCC";
                viking_mxcc_present = 1;
                srmmu_cache_pagetables = 1;
        }

        sparc32_cachetlb_ops = (const struct sparc32_cachetlb_ops *)
                &viking_ops;
#ifdef CONFIG_SMP
        if (sparc_cpu_model == sun4d)
                sparc32_cachetlb_ops = (const struct sparc32_cachetlb_ops *)
                        &viking_sun4d_smp_ops;
#endif

        poke_srmmu = poke_viking;
}

/* Probe for the srmmu chip version. */
static void __init get_srmmu_type(void)
{
        unsigned long mreg, psr;
        unsigned long mod_typ, mod_rev, psr_typ, psr_vers;

        srmmu_modtype = SRMMU_INVAL_MOD;
        hwbug_bitmask = 0;

        mreg = srmmu_get_mmureg(); psr = get_psr();
        mod_typ = (mreg & 0xf0000000) >> 28;
        mod_rev = (mreg & 0x0f000000) >> 24;
        psr_typ = (psr >> 28) & 0xf;
        psr_vers = (psr >> 24) & 0xf;

        /* First, check for sparc-leon. */
        if (sparc_cpu_model == sparc_leon) {
                init_leon();
                return;
        }

        /* Second, check for HyperSparc or Cypress. */
        if(mod_typ == 1) {
                switch(mod_rev) {
                case 7:
                        /* UP or MP Hypersparc */
                        init_hypersparc();
                        break;
                case 0:
                case 2:
                case 10:
                case 11:
                case 12:
                case 13:
                case 14:
                case 15:
                default:
                        prom_printf("Sparc-Linux Cypress support does not longer exit.\n");
                        prom_halt();
                        break;
                }
                return;
        }
        
        /*
         * Now Fujitsu TurboSparc. It might happen that it is
         * in Swift emulation mode, so we will check later...
         */
        if (psr_typ == 0 && psr_vers == 5) {
                init_turbosparc();
                return;
        }

        /* Next check for Fujitsu Swift. */
        if(psr_typ == 0 && psr_vers == 4) {
                phandle cpunode;
                char node_str[128];

                /* Look if it is not a TurboSparc emulating Swift... */
                cpunode = prom_getchild(prom_root_node);
                while((cpunode = prom_getsibling(cpunode)) != 0) {
                        prom_getstring(cpunode, "device_type", node_str, sizeof(node_str));
                        if(!strcmp(node_str, "cpu")) {
                                if (!prom_getintdefault(cpunode, "psr-implementation", 1) &&
                                    prom_getintdefault(cpunode, "psr-version", 1) == 5) {
                                        init_turbosparc();
                                        return;
                                }
                                break;
                        }
                }
                
                init_swift();
                return;
        }

        /* Now the Viking family of srmmu. */
        if(psr_typ == 4 &&
           ((psr_vers == 0) ||
            ((psr_vers == 1) && (mod_typ == 0) && (mod_rev == 0)))) {
                init_viking();
                return;
        }

        /* Finally the Tsunami. */
        if(psr_typ == 4 && psr_vers == 1 && (mod_typ || mod_rev)) {
                init_tsunami();
                return;
        }

        /* Oh well */
        srmmu_is_bad();
}

#ifdef CONFIG_SMP
/* Local cross-calls. */
static void smp_flush_page_for_dma(unsigned long page)
{
        xc1((smpfunc_t) local_ops->page_for_dma, page);
        local_ops->page_for_dma(page);
}

static void smp_flush_cache_all(void)
{
        xc0((smpfunc_t) local_ops->cache_all);
        local_ops->cache_all();
}

static void smp_flush_tlb_all(void)
{
        xc0((smpfunc_t) local_ops->tlb_all);
        local_ops->tlb_all();
}

static void smp_flush_cache_mm(struct mm_struct *mm)
{
        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask))
                        xc1((smpfunc_t) local_ops->cache_mm, (unsigned long) mm);
                local_ops->cache_mm(mm);
        }
}

static void smp_flush_tlb_mm(struct mm_struct *mm)
{
        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask)) {
                        xc1((smpfunc_t) local_ops->tlb_mm, (unsigned long) mm);
                        if (atomic_read(&mm->mm_users) == 1 && current->active_mm == mm)
                                cpumask_copy(mm_cpumask(mm),
                                             cpumask_of(smp_processor_id()));
                }
                local_ops->tlb_mm(mm);
        }
}

static void smp_flush_cache_range(struct vm_area_struct *vma,
                                  unsigned long start,
                                  unsigned long end)
{
        struct mm_struct *mm = vma->vm_mm;

        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask))
                        xc3((smpfunc_t) local_ops->cache_range,
                            (unsigned long) vma, start, end);
                local_ops->cache_range(vma, start, end);
        }
}

static void smp_flush_tlb_range(struct vm_area_struct *vma,
                                unsigned long start,
                                unsigned long end)
{
        struct mm_struct *mm = vma->vm_mm;

        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask))
                        xc3((smpfunc_t) local_ops->tlb_range,
                            (unsigned long) vma, start, end);
                local_ops->tlb_range(vma, start, end);
        }
}

static void smp_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
{
        struct mm_struct *mm = vma->vm_mm;

        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask))
                        xc2((smpfunc_t) local_ops->cache_page,
                            (unsigned long) vma, page);
                local_ops->cache_page(vma, page);
        }
}

static void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
        struct mm_struct *mm = vma->vm_mm;

        if (mm->context != NO_CONTEXT) {
                cpumask_t cpu_mask;
                cpumask_copy(&cpu_mask, mm_cpumask(mm));
                cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
                if (!cpumask_empty(&cpu_mask))
                        xc2((smpfunc_t) local_ops->tlb_page,
                            (unsigned long) vma, page);
                local_ops->tlb_page(vma, page);
        }
}

static void smp_flush_page_to_ram(unsigned long page)
{
        /* Current theory is that those who call this are the one's
         * who have just dirtied their cache with the pages contents
         * in kernel space, therefore we only run this on local cpu.
         *
         * XXX This experiment failed, research further... -DaveM
         */
#if 1
        xc1((smpfunc_t) local_ops->page_to_ram, page);
#endif
        local_ops->page_to_ram(page);
}

static void smp_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr)
{
        cpumask_t cpu_mask;
        cpumask_copy(&cpu_mask, mm_cpumask(mm));
        cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
        if (!cpumask_empty(&cpu_mask))
                xc2((smpfunc_t) local_ops->sig_insns,
                    (unsigned long) mm, insn_addr);
        local_ops->sig_insns(mm, insn_addr);
}

static struct sparc32_cachetlb_ops smp_cachetlb_ops = {
        .cache_all      = smp_flush_cache_all,
        .cache_mm       = smp_flush_cache_mm,
        .cache_page     = smp_flush_cache_page,
        .cache_range    = smp_flush_cache_range,
        .tlb_all        = smp_flush_tlb_all,
        .tlb_mm         = smp_flush_tlb_mm,
        .tlb_page       = smp_flush_tlb_page,
        .tlb_range      = smp_flush_tlb_range,
        .page_to_ram    = smp_flush_page_to_ram,
        .sig_insns      = smp_flush_sig_insns,
        .page_for_dma   = smp_flush_page_for_dma,
};
#endif

/* Load up routines and constants for sun4m and sun4d mmu */
void __init load_mmu(void)
{
        extern void ld_mmu_iommu(void);
        extern void ld_mmu_iounit(void);

        /* Functions */
        get_srmmu_type();

#ifdef CONFIG_SMP
        /* El switcheroo... */
        local_ops = sparc32_cachetlb_ops;

        if (sparc_cpu_model == sun4d || sparc_cpu_model == sparc_leon) {
                smp_cachetlb_ops.tlb_all = local_ops->tlb_all;
                smp_cachetlb_ops.tlb_mm = local_ops->tlb_mm;
                smp_cachetlb_ops.tlb_range = local_ops->tlb_range;
                smp_cachetlb_ops.tlb_page = local_ops->tlb_page;
        }

        if (poke_srmmu == poke_viking) {
                /* Avoid unnecessary cross calls. */
                smp_cachetlb_ops.cache_all = local_ops->cache_all;
                smp_cachetlb_ops.cache_mm = local_ops->cache_mm;
                smp_cachetlb_ops.cache_range = local_ops->cache_range;
                smp_cachetlb_ops.cache_page = local_ops->cache_page;

                smp_cachetlb_ops.page_to_ram = local_ops->page_to_ram;
                smp_cachetlb_ops.sig_insns = local_ops->sig_insns;
                smp_cachetlb_ops.page_for_dma = local_ops->page_for_dma;
        }

        /* It really is const after this point. */
        sparc32_cachetlb_ops = (const struct sparc32_cachetlb_ops *)
                &smp_cachetlb_ops;
#endif

        if (sparc_cpu_model == sun4d)
                ld_mmu_iounit();
        else
                ld_mmu_iommu();
#ifdef CONFIG_SMP
        if (sparc_cpu_model == sun4d)
                sun4d_init_smp();
        else if (sparc_cpu_model == sparc_leon)
                leon_init_smp();
        else
                sun4m_init_smp();
#endif
}