[MIPS] Handle aliases in vmalloc correctly.

[deliverable/linux.git] / arch / mips / mm / c-r4k.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
 * Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Ralf Baechle (ralf@gnu.org)
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/bitops.h>

#include <asm/bcache.h>
#include <asm/bootinfo.h>
#include <asm/cache.h>
#include <asm/cacheops.h>
#include <asm/cpu.h>
#include <asm/cpu-features.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/r4kcache.h>
#include <asm/sections.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/war.h>
#include <asm/cacheflush.h> /* for run_uncached() */


/*
 * Special Variant of smp_call_function for use by cache functions:
 *
 *  o No return value
 *  o collapses to normal function call on UP kernels
 *  o collapses to normal function call on systems with a single shared
 *    primary cache.
 */
static inline void r4k_on_each_cpu(void (*func) (void *info), void *info,
                                   int retry, int wait)
{
        preempt_disable();

#if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC)
        smp_call_function(func, info, retry, wait);
#endif
        func(info);
        preempt_enable();
}

/*
 * Must die.
 */
static unsigned long icache_size __read_mostly;
static unsigned long dcache_size __read_mostly;
static unsigned long scache_size __read_mostly;

/*
 * Dummy cache handling routines for machines without boardcaches
 */
static void cache_noop(void) {}

static struct bcache_ops no_sc_ops = {
        .bc_enable = (void *)cache_noop,
        .bc_disable = (void *)cache_noop,
        .bc_wback_inv = (void *)cache_noop,
        .bc_inv = (void *)cache_noop
};

struct bcache_ops *bcops = &no_sc_ops;

#define cpu_is_r4600_v1_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002010)
#define cpu_is_r4600_v2_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002020)

#define R4600_HIT_CACHEOP_WAR_IMPL                                      \
do {                                                                    \
        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())            \
                *(volatile unsigned long *)CKSEG1;                      \
        if (R4600_V1_HIT_CACHEOP_WAR)                                   \
                __asm__ __volatile__("nop;nop;nop;nop");                \
} while (0)

static void (*r4k_blast_dcache_page)(unsigned long addr);

static inline void r4k_blast_dcache_page_dc32(unsigned long addr)
{
        R4600_HIT_CACHEOP_WAR_IMPL;
        blast_dcache32_page(addr);
}

static void __cpuinit r4k_blast_dcache_page_setup(void)
{
        unsigned long  dc_lsize = cpu_dcache_line_size();

        if (dc_lsize == 0)
                r4k_blast_dcache_page = (void *)cache_noop;
        else if (dc_lsize == 16)
                r4k_blast_dcache_page = blast_dcache16_page;
        else if (dc_lsize == 32)
                r4k_blast_dcache_page = r4k_blast_dcache_page_dc32;
}

static void (* r4k_blast_dcache_page_indexed)(unsigned long addr);

static void __cpuinit r4k_blast_dcache_page_indexed_setup(void)
{
        unsigned long dc_lsize = cpu_dcache_line_size();

        if (dc_lsize == 0)
                r4k_blast_dcache_page_indexed = (void *)cache_noop;
        else if (dc_lsize == 16)
                r4k_blast_dcache_page_indexed = blast_dcache16_page_indexed;
        else if (dc_lsize == 32)
                r4k_blast_dcache_page_indexed = blast_dcache32_page_indexed;
}

static void (* r4k_blast_dcache)(void);

static void __cpuinit r4k_blast_dcache_setup(void)
{
        unsigned long dc_lsize = cpu_dcache_line_size();

        if (dc_lsize == 0)
                r4k_blast_dcache = (void *)cache_noop;
        else if (dc_lsize == 16)
                r4k_blast_dcache = blast_dcache16;
        else if (dc_lsize == 32)
                r4k_blast_dcache = blast_dcache32;
}

/* force code alignment (used for TX49XX_ICACHE_INDEX_INV_WAR) */
#define JUMP_TO_ALIGN(order) \
        __asm__ __volatile__( \
                "b\t1f\n\t" \
                ".align\t" #order "\n\t" \
                "1:\n\t" \
                )
#define CACHE32_UNROLL32_ALIGN  JUMP_TO_ALIGN(10) /* 32 * 32 = 1024 */
#define CACHE32_UNROLL32_ALIGN2 JUMP_TO_ALIGN(11)

static inline void blast_r4600_v1_icache32(void)
{
        unsigned long flags;

        local_irq_save(flags);
        blast_icache32();
        local_irq_restore(flags);
}

static inline void tx49_blast_icache32(void)
{
        unsigned long start = INDEX_BASE;
        unsigned long end = start + current_cpu_data.icache.waysize;
        unsigned long ws_inc = 1UL << current_cpu_data.icache.waybit;
        unsigned long ws_end = current_cpu_data.icache.ways <<
                               current_cpu_data.icache.waybit;
        unsigned long ws, addr;

        CACHE32_UNROLL32_ALIGN2;
        /* I'm in even chunk.  blast odd chunks */
        for (ws = 0; ws < ws_end; ws += ws_inc)
                for (addr = start + 0x400; addr < end; addr += 0x400 * 2)
                        cache32_unroll32(addr|ws, Index_Invalidate_I);
        CACHE32_UNROLL32_ALIGN;
        /* I'm in odd chunk.  blast even chunks */
        for (ws = 0; ws < ws_end; ws += ws_inc)
                for (addr = start; addr < end; addr += 0x400 * 2)
                        cache32_unroll32(addr|ws, Index_Invalidate_I);
}

static inline void blast_icache32_r4600_v1_page_indexed(unsigned long page)
{
        unsigned long flags;

        local_irq_save(flags);
        blast_icache32_page_indexed(page);
        local_irq_restore(flags);
}

static inline void tx49_blast_icache32_page_indexed(unsigned long page)
{
        unsigned long indexmask = current_cpu_data.icache.waysize - 1;
        unsigned long start = INDEX_BASE + (page & indexmask);
        unsigned long end = start + PAGE_SIZE;
        unsigned long ws_inc = 1UL << current_cpu_data.icache.waybit;
        unsigned long ws_end = current_cpu_data.icache.ways <<
                               current_cpu_data.icache.waybit;
        unsigned long ws, addr;

        CACHE32_UNROLL32_ALIGN2;
        /* I'm in even chunk.  blast odd chunks */
        for (ws = 0; ws < ws_end; ws += ws_inc)
                for (addr = start + 0x400; addr < end; addr += 0x400 * 2)
                        cache32_unroll32(addr|ws, Index_Invalidate_I);
        CACHE32_UNROLL32_ALIGN;
        /* I'm in odd chunk.  blast even chunks */
        for (ws = 0; ws < ws_end; ws += ws_inc)
                for (addr = start; addr < end; addr += 0x400 * 2)
                        cache32_unroll32(addr|ws, Index_Invalidate_I);
}

static void (* r4k_blast_icache_page)(unsigned long addr);

static void __cpuinit r4k_blast_icache_page_setup(void)
{
        unsigned long ic_lsize = cpu_icache_line_size();

        if (ic_lsize == 0)
                r4k_blast_icache_page = (void *)cache_noop;
        else if (ic_lsize == 16)
                r4k_blast_icache_page = blast_icache16_page;
        else if (ic_lsize == 32)
                r4k_blast_icache_page = blast_icache32_page;
        else if (ic_lsize == 64)
                r4k_blast_icache_page = blast_icache64_page;
}


static void (* r4k_blast_icache_page_indexed)(unsigned long addr);

static void __cpuinit r4k_blast_icache_page_indexed_setup(void)
{
        unsigned long ic_lsize = cpu_icache_line_size();

        if (ic_lsize == 0)
                r4k_blast_icache_page_indexed = (void *)cache_noop;
        else if (ic_lsize == 16)
                r4k_blast_icache_page_indexed = blast_icache16_page_indexed;
        else if (ic_lsize == 32) {
                if (R4600_V1_INDEX_ICACHEOP_WAR && cpu_is_r4600_v1_x())
                        r4k_blast_icache_page_indexed =
                                blast_icache32_r4600_v1_page_indexed;
                else if (TX49XX_ICACHE_INDEX_INV_WAR)
                        r4k_blast_icache_page_indexed =
                                tx49_blast_icache32_page_indexed;
                else
                        r4k_blast_icache_page_indexed =
                                blast_icache32_page_indexed;
        } else if (ic_lsize == 64)
                r4k_blast_icache_page_indexed = blast_icache64_page_indexed;
}

static void (* r4k_blast_icache)(void);

static void __cpuinit r4k_blast_icache_setup(void)
{
        unsigned long ic_lsize = cpu_icache_line_size();

        if (ic_lsize == 0)
                r4k_blast_icache = (void *)cache_noop;
        else if (ic_lsize == 16)
                r4k_blast_icache = blast_icache16;
        else if (ic_lsize == 32) {
                if (R4600_V1_INDEX_ICACHEOP_WAR && cpu_is_r4600_v1_x())
                        r4k_blast_icache = blast_r4600_v1_icache32;
                else if (TX49XX_ICACHE_INDEX_INV_WAR)
                        r4k_blast_icache = tx49_blast_icache32;
                else
                        r4k_blast_icache = blast_icache32;
        } else if (ic_lsize == 64)
                r4k_blast_icache = blast_icache64;
}

static void (* r4k_blast_scache_page)(unsigned long addr);

static void __cpuinit r4k_blast_scache_page_setup(void)
{
        unsigned long sc_lsize = cpu_scache_line_size();

        if (scache_size == 0)
                r4k_blast_scache_page = (void *)cache_noop;
        else if (sc_lsize == 16)
                r4k_blast_scache_page = blast_scache16_page;
        else if (sc_lsize == 32)
                r4k_blast_scache_page = blast_scache32_page;
        else if (sc_lsize == 64)
                r4k_blast_scache_page = blast_scache64_page;
        else if (sc_lsize == 128)
                r4k_blast_scache_page = blast_scache128_page;
}

static void (* r4k_blast_scache_page_indexed)(unsigned long addr);

static void __cpuinit r4k_blast_scache_page_indexed_setup(void)
{
        unsigned long sc_lsize = cpu_scache_line_size();

        if (scache_size == 0)
                r4k_blast_scache_page_indexed = (void *)cache_noop;
        else if (sc_lsize == 16)
                r4k_blast_scache_page_indexed = blast_scache16_page_indexed;
        else if (sc_lsize == 32)
                r4k_blast_scache_page_indexed = blast_scache32_page_indexed;
        else if (sc_lsize == 64)
                r4k_blast_scache_page_indexed = blast_scache64_page_indexed;
        else if (sc_lsize == 128)
                r4k_blast_scache_page_indexed = blast_scache128_page_indexed;
}

static void (* r4k_blast_scache)(void);

static void __cpuinit r4k_blast_scache_setup(void)
{
        unsigned long sc_lsize = cpu_scache_line_size();

        if (scache_size == 0)
                r4k_blast_scache = (void *)cache_noop;
        else if (sc_lsize == 16)
                r4k_blast_scache = blast_scache16;
        else if (sc_lsize == 32)
                r4k_blast_scache = blast_scache32;
        else if (sc_lsize == 64)
                r4k_blast_scache = blast_scache64;
        else if (sc_lsize == 128)
                r4k_blast_scache = blast_scache128;
}

static inline void local_r4k___flush_cache_all(void * args)
{
#if defined(CONFIG_CPU_LOONGSON2)
        r4k_blast_scache();
        return;
#endif
        r4k_blast_dcache();
        r4k_blast_icache();

        switch (current_cpu_type()) {
        case CPU_R4000SC:
        case CPU_R4000MC:
        case CPU_R4400SC:
        case CPU_R4400MC:
        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
                r4k_blast_scache();
        }
}

static void r4k___flush_cache_all(void)
{
        r4k_on_each_cpu(local_r4k___flush_cache_all, NULL, 1, 1);
}

static inline int has_valid_asid(const struct mm_struct *mm)
{
#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
        int i;

        for_each_online_cpu(i)
                if (cpu_context(i, mm))
                        return 1;

        return 0;
#else
        return cpu_context(smp_processor_id(), mm);
#endif
}

static void r4k__flush_cache_vmap(void)
{
        r4k_blast_dcache();
}

static void r4k__flush_cache_vunmap(void)
{
        r4k_blast_dcache();
}

static inline void local_r4k_flush_cache_range(void * args)
{
        struct vm_area_struct *vma = args;
        int exec = vma->vm_flags & VM_EXEC;

        if (!(has_valid_asid(vma->vm_mm)))
                return;

        r4k_blast_dcache();
        if (exec)
                r4k_blast_icache();
}

static void r4k_flush_cache_range(struct vm_area_struct *vma,
        unsigned long start, unsigned long end)
{
        int exec = vma->vm_flags & VM_EXEC;

        if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc))
                r4k_on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1);
}

static inline void local_r4k_flush_cache_mm(void * args)
{
        struct mm_struct *mm = args;

        if (!has_valid_asid(mm))
                return;

        /*
         * Kludge alert.  For obscure reasons R4000SC and R4400SC go nuts if we
         * only flush the primary caches but R10000 and R12000 behave sane ...
         * R4000SC and R4400SC indexed S-cache ops also invalidate primary
         * caches, so we can bail out early.
         */
        if (current_cpu_type() == CPU_R4000SC ||
            current_cpu_type() == CPU_R4000MC ||
            current_cpu_type() == CPU_R4400SC ||
            current_cpu_type() == CPU_R4400MC) {
                r4k_blast_scache();
                return;
        }

        r4k_blast_dcache();
}

static void r4k_flush_cache_mm(struct mm_struct *mm)
{
        if (!cpu_has_dc_aliases)
                return;

        r4k_on_each_cpu(local_r4k_flush_cache_mm, mm, 1, 1);
}

struct flush_cache_page_args {
        struct vm_area_struct *vma;
        unsigned long addr;
        unsigned long pfn;
};

static inline void local_r4k_flush_cache_page(void *args)
{
        struct flush_cache_page_args *fcp_args = args;
        struct vm_area_struct *vma = fcp_args->vma;
        unsigned long addr = fcp_args->addr;
        struct page *page = pfn_to_page(fcp_args->pfn);
        int exec = vma->vm_flags & VM_EXEC;
        struct mm_struct *mm = vma->vm_mm;
        pgd_t *pgdp;
        pud_t *pudp;
        pmd_t *pmdp;
        pte_t *ptep;
        void *vaddr;

        /*
         * If ownes no valid ASID yet, cannot possibly have gotten
         * this page into the cache.
         */
        if (!has_valid_asid(mm))
                return;

        addr &= PAGE_MASK;
        pgdp = pgd_offset(mm, addr);
        pudp = pud_offset(pgdp, addr);
        pmdp = pmd_offset(pudp, addr);
        ptep = pte_offset(pmdp, addr);

        /*
         * If the page isn't marked valid, the page cannot possibly be
         * in the cache.
         */
        if (!(pte_present(*ptep)))
                return;

        if ((mm == current->active_mm) && (pte_val(*ptep) & _PAGE_VALID))
                vaddr = NULL;
        else {
                /*
                 * Use kmap_coherent or kmap_atomic to do flushes for
                 * another ASID than the current one.
                 */
                if (cpu_has_dc_aliases)
                        vaddr = kmap_coherent(page, addr);
                else
                        vaddr = kmap_atomic(page, KM_USER0);
                addr = (unsigned long)vaddr;
        }

        if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
                r4k_blast_dcache_page(addr);
        }
        if (exec) {
                if (vaddr && cpu_has_vtag_icache && mm == current->active_mm) {
                        int cpu = smp_processor_id();

                        if (cpu_context(cpu, mm) != 0)
                                drop_mmu_context(mm, cpu);
                } else
                        r4k_blast_icache_page(addr);
        }

        if (vaddr) {
                if (cpu_has_dc_aliases)
                        kunmap_coherent();
                else
                        kunmap_atomic(vaddr, KM_USER0);
        }
}

static void r4k_flush_cache_page(struct vm_area_struct *vma,
        unsigned long addr, unsigned long pfn)
{
        struct flush_cache_page_args args;

        args.vma = vma;
        args.addr = addr;
        args.pfn = pfn;

        r4k_on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1);
}

static inline void local_r4k_flush_data_cache_page(void * addr)
{
        r4k_blast_dcache_page((unsigned long) addr);
}

static void r4k_flush_data_cache_page(unsigned long addr)
{
        if (in_atomic())
                local_r4k_flush_data_cache_page((void *)addr);
        else
                r4k_on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr,
                                1, 1);
}

struct flush_icache_range_args {
        unsigned long start;
        unsigned long end;
};

static inline void local_r4k_flush_icache_range(void *args)
{
        struct flush_icache_range_args *fir_args = args;
        unsigned long start = fir_args->start;
        unsigned long end = fir_args->end;

        if (!cpu_has_ic_fills_f_dc) {
                if (end - start >= dcache_size) {
                        r4k_blast_dcache();
                } else {
                        R4600_HIT_CACHEOP_WAR_IMPL;
                        protected_blast_dcache_range(start, end);
                }
        }

        if (end - start > icache_size)
                r4k_blast_icache();
        else
                protected_blast_icache_range(start, end);
}

static void r4k_flush_icache_range(unsigned long start, unsigned long end)
{
        struct flush_icache_range_args args;

        args.start = start;
        args.end = end;

        r4k_on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1);
        instruction_hazard();
}

#ifdef CONFIG_DMA_NONCOHERENT

static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
{
        /* Catch bad driver code */
        BUG_ON(size == 0);

        if (cpu_has_inclusive_pcaches) {
                if (size >= scache_size)
                        r4k_blast_scache();
                else
                        blast_scache_range(addr, addr + size);
                return;
        }

        /*
         * Either no secondary cache or the available caches don't have the
         * subset property so we have to flush the primary caches
         * explicitly
         */
        if (size >= dcache_size) {
                r4k_blast_dcache();
        } else {
                R4600_HIT_CACHEOP_WAR_IMPL;
                blast_dcache_range(addr, addr + size);
        }

        bc_wback_inv(addr, size);
}

static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
{
        /* Catch bad driver code */
        BUG_ON(size == 0);

        if (cpu_has_inclusive_pcaches) {
                if (size >= scache_size)
                        r4k_blast_scache();
                else
                        blast_inv_scache_range(addr, addr + size);
                return;
        }

        if (size >= dcache_size) {
                r4k_blast_dcache();
        } else {
                R4600_HIT_CACHEOP_WAR_IMPL;
                blast_inv_dcache_range(addr, addr + size);
        }

        bc_inv(addr, size);
}
#endif /* CONFIG_DMA_NONCOHERENT */

/*
 * While we're protected against bad userland addresses we don't care
 * very much about what happens in that case.  Usually a segmentation
 * fault will dump the process later on anyway ...
 */
static void local_r4k_flush_cache_sigtramp(void * arg)
{
        unsigned long ic_lsize = cpu_icache_line_size();
        unsigned long dc_lsize = cpu_dcache_line_size();
        unsigned long sc_lsize = cpu_scache_line_size();
        unsigned long addr = (unsigned long) arg;

        R4600_HIT_CACHEOP_WAR_IMPL;
        if (dc_lsize)
                protected_writeback_dcache_line(addr & ~(dc_lsize - 1));
        if (!cpu_icache_snoops_remote_store && scache_size)
                protected_writeback_scache_line(addr & ~(sc_lsize - 1));
        if (ic_lsize)
                protected_flush_icache_line(addr & ~(ic_lsize - 1));
        if (MIPS4K_ICACHE_REFILL_WAR) {
                __asm__ __volatile__ (
                        ".set push\n\t"
                        ".set noat\n\t"
                        ".set mips3\n\t"
#ifdef CONFIG_32BIT
                        "la     $at,1f\n\t"
#endif
#ifdef CONFIG_64BIT
                        "dla    $at,1f\n\t"
#endif
                        "cache  %0,($at)\n\t"
                        "nop; nop; nop\n"
                        "1:\n\t"
                        ".set pop"
                        :
                        : "i" (Hit_Invalidate_I));
        }
        if (MIPS_CACHE_SYNC_WAR)
                __asm__ __volatile__ ("sync");
}

static void r4k_flush_cache_sigtramp(unsigned long addr)
{
        r4k_on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1);
}

static void r4k_flush_icache_all(void)
{
        if (cpu_has_vtag_icache)
                r4k_blast_icache();
}

static inline void rm7k_erratum31(void)
{
        const unsigned long ic_lsize = 32;
        unsigned long addr;

        /* RM7000 erratum #31. The icache is screwed at startup. */
        write_c0_taglo(0);
        write_c0_taghi(0);

        for (addr = INDEX_BASE; addr <= INDEX_BASE + 4096; addr += ic_lsize) {
                __asm__ __volatile__ (
                        ".set push\n\t"
                        ".set noreorder\n\t"
                        ".set mips3\n\t"
                        "cache\t%1, 0(%0)\n\t"
                        "cache\t%1, 0x1000(%0)\n\t"
                        "cache\t%1, 0x2000(%0)\n\t"
                        "cache\t%1, 0x3000(%0)\n\t"
                        "cache\t%2, 0(%0)\n\t"
                        "cache\t%2, 0x1000(%0)\n\t"
                        "cache\t%2, 0x2000(%0)\n\t"
                        "cache\t%2, 0x3000(%0)\n\t"
                        "cache\t%1, 0(%0)\n\t"
                        "cache\t%1, 0x1000(%0)\n\t"
                        "cache\t%1, 0x2000(%0)\n\t"
                        "cache\t%1, 0x3000(%0)\n\t"
                        ".set pop\n"
                        :
                        : "r" (addr), "i" (Index_Store_Tag_I), "i" (Fill));
        }
}

static char *way_string[] __cpuinitdata = { NULL, "direct mapped", "2-way",
        "3-way", "4-way", "5-way", "6-way", "7-way", "8-way"
};

static void __cpuinit probe_pcache(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int config = read_c0_config();
        unsigned int prid = read_c0_prid();
        unsigned long config1;
        unsigned int lsize;

        switch (c->cputype) {
        case CPU_R4600:                 /* QED style two way caches? */
        case CPU_R4700:
        case CPU_R5000:
        case CPU_NEVADA:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 2;
                c->icache.waybit = __ffs(icache_size/2);

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 2;
                c->dcache.waybit= __ffs(dcache_size/2);

                c->options |= MIPS_CPU_CACHE_CDEX_P;
                break;

        case CPU_R5432:
        case CPU_R5500:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 2;
                c->icache.waybit= 0;

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 2;
                c->dcache.waybit = 0;

                c->options |= MIPS_CPU_CACHE_CDEX_P;
                break;

        case CPU_TX49XX:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 4;
                c->icache.waybit= 0;

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 4;
                c->dcache.waybit = 0;

                c->options |= MIPS_CPU_CACHE_CDEX_P;
                c->options |= MIPS_CPU_PREFETCH;
                break;

        case CPU_R4000PC:
        case CPU_R4000SC:
        case CPU_R4000MC:
        case CPU_R4400PC:
        case CPU_R4400SC:
        case CPU_R4400MC:
        case CPU_R4300:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 1;
                c->icache.waybit = 0;   /* doesn't matter */

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 1;
                c->dcache.waybit = 0;   /* does not matter */

                c->options |= MIPS_CPU_CACHE_CDEX_P;
                break;

        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
                icache_size = 1 << (12 + ((config & R10K_CONF_IC) >> 29));
                c->icache.linesz = 64;
                c->icache.ways = 2;
                c->icache.waybit = 0;

                dcache_size = 1 << (12 + ((config & R10K_CONF_DC) >> 26));
                c->dcache.linesz = 32;
                c->dcache.ways = 2;
                c->dcache.waybit = 0;

                c->options |= MIPS_CPU_PREFETCH;
                break;

        case CPU_VR4133:
                write_c0_config(config & ~VR41_CONF_P4K);
        case CPU_VR4131:
                /* Workaround for cache instruction bug of VR4131 */
                if (c->processor_id == 0x0c80U || c->processor_id == 0x0c81U ||
                    c->processor_id == 0x0c82U) {
                        config |= 0x00400000U;
                        if (c->processor_id == 0x0c80U)
                                config |= VR41_CONF_BP;
                        write_c0_config(config);
                } else
                        c->options |= MIPS_CPU_CACHE_CDEX_P;

                icache_size = 1 << (10 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 2;
                c->icache.waybit = __ffs(icache_size/2);

                dcache_size = 1 << (10 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 2;
                c->dcache.waybit = __ffs(dcache_size/2);
                break;

        case CPU_VR41XX:
        case CPU_VR4111:
        case CPU_VR4121:
        case CPU_VR4122:
        case CPU_VR4181:
        case CPU_VR4181A:
                icache_size = 1 << (10 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 1;
                c->icache.waybit = 0;   /* doesn't matter */

                dcache_size = 1 << (10 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 1;
                c->dcache.waybit = 0;   /* does not matter */

                c->options |= MIPS_CPU_CACHE_CDEX_P;
                break;

        case CPU_RM7000:
                rm7k_erratum31();

        case CPU_RM9000:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                c->icache.ways = 4;
                c->icache.waybit = __ffs(icache_size / c->icache.ways);

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                c->dcache.ways = 4;
                c->dcache.waybit = __ffs(dcache_size / c->dcache.ways);

#if !defined(CONFIG_SMP) || !defined(RM9000_CDEX_SMP_WAR)
                c->options |= MIPS_CPU_CACHE_CDEX_P;
#endif
                c->options |= MIPS_CPU_PREFETCH;
                break;

        case CPU_LOONGSON2:
                icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
                c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
                if (prid & 0x3)
                        c->icache.ways = 4;
                else
                        c->icache.ways = 2;
                c->icache.waybit = 0;

                dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
                c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
                if (prid & 0x3)
                        c->dcache.ways = 4;
                else
                        c->dcache.ways = 2;
                c->dcache.waybit = 0;
                break;

        default:
                if (!(config & MIPS_CONF_M))
                        panic("Don't know how to probe P-caches on this cpu.");

                /*
                 * So we seem to be a MIPS32 or MIPS64 CPU
                 * So let's probe the I-cache ...
                 */
                config1 = read_c0_config1();

                if ((lsize = ((config1 >> 19) & 7)))
                        c->icache.linesz = 2 << lsize;
                else
                        c->icache.linesz = lsize;
                c->icache.sets = 64 << ((config1 >> 22) & 7);
                c->icache.ways = 1 + ((config1 >> 16) & 7);

                icache_size = c->icache.sets *
                              c->icache.ways *
                              c->icache.linesz;
                c->icache.waybit = __ffs(icache_size/c->icache.ways);

                if (config & 0x8)               /* VI bit */
                        c->icache.flags |= MIPS_CACHE_VTAG;

                /*
                 * Now probe the MIPS32 / MIPS64 data cache.
                 */
                c->dcache.flags = 0;

                if ((lsize = ((config1 >> 10) & 7)))
                        c->dcache.linesz = 2 << lsize;
                else
                        c->dcache.linesz= lsize;
                c->dcache.sets = 64 << ((config1 >> 13) & 7);
                c->dcache.ways = 1 + ((config1 >> 7) & 7);

                dcache_size = c->dcache.sets *
                              c->dcache.ways *
                              c->dcache.linesz;
                c->dcache.waybit = __ffs(dcache_size/c->dcache.ways);

                c->options |= MIPS_CPU_PREFETCH;
                break;
        }

        /*
         * Processor configuration sanity check for the R4000SC erratum
         * #5.  With page sizes larger than 32kB there is no possibility
         * to get a VCE exception anymore so we don't care about this
         * misconfiguration.  The case is rather theoretical anyway;
         * presumably no vendor is shipping his hardware in the "bad"
         * configuration.
         */
        if ((prid & 0xff00) == PRID_IMP_R4000 && (prid & 0xff) < 0x40 &&
            !(config & CONF_SC) && c->icache.linesz != 16 &&
            PAGE_SIZE <= 0x8000)
                panic("Improper R4000SC processor configuration detected");

        /* compute a couple of other cache variables */
        c->icache.waysize = icache_size / c->icache.ways;
        c->dcache.waysize = dcache_size / c->dcache.ways;

        c->icache.sets = c->icache.linesz ?
                icache_size / (c->icache.linesz * c->icache.ways) : 0;
        c->dcache.sets = c->dcache.linesz ?
                dcache_size / (c->dcache.linesz * c->dcache.ways) : 0;

        /*
         * R10000 and R12000 P-caches are odd in a positive way.  They're 32kB
         * 2-way virtually indexed so normally would suffer from aliases.  So
         * normally they'd suffer from aliases but magic in the hardware deals
         * with that for us so we don't need to take care ourselves.
         */
        switch (c->cputype) {
        case CPU_20KC:
        case CPU_25KF:
        case CPU_SB1:
        case CPU_SB1A:
                c->dcache.flags |= MIPS_CACHE_PINDEX;
                break;

        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
                break;

        case CPU_24K:
        case CPU_34K:
        case CPU_74K:
                if ((read_c0_config7() & (1 << 16))) {
                        /* effectively physically indexed dcache,
                           thus no virtual aliases. */
                        c->dcache.flags |= MIPS_CACHE_PINDEX;
                        break;
                }
        default:
                if (c->dcache.waysize > PAGE_SIZE)
                        c->dcache.flags |= MIPS_CACHE_ALIASES;
        }

        switch (c->cputype) {
        case CPU_20KC:
                /*
                 * Some older 20Kc chips doesn't have the 'VI' bit in
                 * the config register.
                 */
                c->icache.flags |= MIPS_CACHE_VTAG;
                break;

        case CPU_AU1000:
        case CPU_AU1500:
        case CPU_AU1100:
        case CPU_AU1550:
        case CPU_AU1200:
        case CPU_AU1210:
        case CPU_AU1250:
                c->icache.flags |= MIPS_CACHE_IC_F_DC;
                break;
        }

#ifdef  CONFIG_CPU_LOONGSON2
        /*
         * LOONGSON2 has 4 way icache, but when using indexed cache op,
         * one op will act on all 4 ways
         */
        c->icache.ways = 1;
#endif

        printk("Primary instruction cache %ldkB, %s, %s, linesize %d bytes.\n",
               icache_size >> 10,
               cpu_has_vtag_icache ? "VIVT" : "VIPT",
               way_string[c->icache.ways], c->icache.linesz);

        printk("Primary data cache %ldkB, %s, %s, %s, linesize %d bytes\n",
               dcache_size >> 10, way_string[c->dcache.ways],
               (c->dcache.flags & MIPS_CACHE_PINDEX) ? "PIPT" : "VIPT",
               (c->dcache.flags & MIPS_CACHE_ALIASES) ?
                        "cache aliases" : "no aliases",
               c->dcache.linesz);
}

/*
 * If you even _breathe_ on this function, look at the gcc output and make sure
 * it does not pop things on and off the stack for the cache sizing loop that
 * executes in KSEG1 space or else you will crash and burn badly.  You have
 * been warned.
 */
static int __cpuinit probe_scache(void)
{
        unsigned long flags, addr, begin, end, pow2;
        unsigned int config = read_c0_config();
        struct cpuinfo_mips *c = &current_cpu_data;
        int tmp;

        if (config & CONF_SC)
                return 0;

        begin = (unsigned long) &_stext;
        begin &= ~((4 * 1024 * 1024) - 1);
        end = begin + (4 * 1024 * 1024);

        /*
         * This is such a bitch, you'd think they would make it easy to do
         * this.  Away you daemons of stupidity!
         */
        local_irq_save(flags);

        /* Fill each size-multiple cache line with a valid tag. */
        pow2 = (64 * 1024);
        for (addr = begin; addr < end; addr = (begin + pow2)) {
                unsigned long *p = (unsigned long *) addr;
                __asm__ __volatile__("nop" : : "r" (*p)); /* whee... */
                pow2 <<= 1;
        }

        /* Load first line with zero (therefore invalid) tag. */
        write_c0_taglo(0);
        write_c0_taghi(0);
        __asm__ __volatile__("nop; nop; nop; nop;"); /* avoid the hazard */
        cache_op(Index_Store_Tag_I, begin);
        cache_op(Index_Store_Tag_D, begin);
        cache_op(Index_Store_Tag_SD, begin);

        /* Now search for the wrap around point. */
        pow2 = (128 * 1024);
        tmp = 0;
        for (addr = begin + (128 * 1024); addr < end; addr = begin + pow2) {
                cache_op(Index_Load_Tag_SD, addr);
                __asm__ __volatile__("nop; nop; nop; nop;"); /* hazard... */
                if (!read_c0_taglo())
                        break;
                pow2 <<= 1;
        }
        local_irq_restore(flags);
        addr -= begin;

        scache_size = addr;
        c->scache.linesz = 16 << ((config & R4K_CONF_SB) >> 22);
        c->scache.ways = 1;
        c->dcache.waybit = 0;           /* does not matter */

        return 1;
}

#if defined(CONFIG_CPU_LOONGSON2)
static void __init loongson2_sc_init(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;

        scache_size = 512*1024;
        c->scache.linesz = 32;
        c->scache.ways = 4;
        c->scache.waybit = 0;
        c->scache.waysize = scache_size / (c->scache.ways);
        c->scache.sets = scache_size / (c->scache.linesz * c->scache.ways);
        pr_info("Unified secondary cache %ldkB %s, linesize %d bytes.\n",
               scache_size >> 10, way_string[c->scache.ways], c->scache.linesz);

        c->options |= MIPS_CPU_INCLUSIVE_CACHES;
}
#endif

extern int r5k_sc_init(void);
extern int rm7k_sc_init(void);
extern int mips_sc_init(void);

static void __cpuinit setup_scache(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int config = read_c0_config();
        int sc_present = 0;

        /*
         * Do the probing thing on R4000SC and R4400SC processors.  Other
         * processors don't have a S-cache that would be relevant to the
         * Linux memory management.
         */
        switch (c->cputype) {
        case CPU_R4000SC:
        case CPU_R4000MC:
        case CPU_R4400SC:
        case CPU_R4400MC:
                sc_present = run_uncached(probe_scache);
                if (sc_present)
                        c->options |= MIPS_CPU_CACHE_CDEX_S;
                break;

        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
                scache_size = 0x80000 << ((config & R10K_CONF_SS) >> 16);
                c->scache.linesz = 64 << ((config >> 13) & 1);
                c->scache.ways = 2;
                c->scache.waybit= 0;
                sc_present = 1;
                break;

        case CPU_R5000:
        case CPU_NEVADA:
#ifdef CONFIG_R5000_CPU_SCACHE
                r5k_sc_init();
#endif
                return;

        case CPU_RM7000:
        case CPU_RM9000:
#ifdef CONFIG_RM7000_CPU_SCACHE
                rm7k_sc_init();
#endif
                return;

#if defined(CONFIG_CPU_LOONGSON2)
        case CPU_LOONGSON2:
                loongson2_sc_init();
                return;
#endif

        default:
                if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
                    c->isa_level == MIPS_CPU_ISA_M32R2 ||
                    c->isa_level == MIPS_CPU_ISA_M64R1 ||
                    c->isa_level == MIPS_CPU_ISA_M64R2) {
#ifdef CONFIG_MIPS_CPU_SCACHE
                        if (mips_sc_init ()) {
                                scache_size = c->scache.ways * c->scache.sets * c->scache.linesz;
                                printk("MIPS secondary cache %ldkB, %s, linesize %d bytes.\n",
                                       scache_size >> 10,
                                       way_string[c->scache.ways], c->scache.linesz);
                        }
#else
                        if (!(c->scache.flags & MIPS_CACHE_NOT_PRESENT))
                                panic("Dunno how to handle MIPS32 / MIPS64 second level cache");
#endif
                        return;
                }
                sc_present = 0;
        }

        if (!sc_present)
                return;

        /* compute a couple of other cache variables */
        c->scache.waysize = scache_size / c->scache.ways;

        c->scache.sets = scache_size / (c->scache.linesz * c->scache.ways);

        printk("Unified secondary cache %ldkB %s, linesize %d bytes.\n",
               scache_size >> 10, way_string[c->scache.ways], c->scache.linesz);

        c->options |= MIPS_CPU_INCLUSIVE_CACHES;
}

void au1x00_fixup_config_od(void)
{
        /*
         * c0_config.od (bit 19) was write only (and read as 0)
         * on the early revisions of Alchemy SOCs.  It disables the bus
         * transaction overlapping and needs to be set to fix various errata.
         */
        switch (read_c0_prid()) {
        case 0x00030100: /* Au1000 DA */
        case 0x00030201: /* Au1000 HA */
        case 0x00030202: /* Au1000 HB */
        case 0x01030200: /* Au1500 AB */
        /*
         * Au1100 errata actually keeps silence about this bit, so we set it
         * just in case for those revisions that require it to be set according
         * to arch/mips/au1000/common/cputable.c
         */
        case 0x02030200: /* Au1100 AB */
        case 0x02030201: /* Au1100 BA */
        case 0x02030202: /* Au1100 BC */
                set_c0_config(1 << 19);
                break;
        }
}

static void __cpuinit coherency_setup(void)
{
        change_c0_config(CONF_CM_CMASK, CONF_CM_DEFAULT);

        /*
         * c0_status.cu=0 specifies that updates by the sc instruction use
         * the coherency mode specified by the TLB; 1 means cachable
         * coherent update on write will be used.  Not all processors have
         * this bit and; some wire it to zero, others like Toshiba had the
         * silly idea of putting something else there ...
         */
        switch (current_cpu_type()) {
        case CPU_R4000PC:
        case CPU_R4000SC:
        case CPU_R4000MC:
        case CPU_R4400PC:
        case CPU_R4400SC:
        case CPU_R4400MC:
                clear_c0_config(CONF_CU);
                break;
        /*
         * We need to catch the early Alchemy SOCs with
         * the write-only co_config.od bit and set it back to one...
         */
        case CPU_AU1000: /* rev. DA, HA, HB */
        case CPU_AU1100: /* rev. AB, BA, BC ?? */
        case CPU_AU1500: /* rev. AB */
                au1x00_fixup_config_od();
                break;
        }
}

void __cpuinit r4k_cache_init(void)
{
        extern void build_clear_page(void);
        extern void build_copy_page(void);
        extern char __weak except_vec2_generic;
        extern char __weak except_vec2_sb1;
        struct cpuinfo_mips *c = &current_cpu_data;

        switch (c->cputype) {
        case CPU_SB1:
        case CPU_SB1A:
                set_uncached_handler(0x100, &except_vec2_sb1, 0x80);
                break;

        default:
                set_uncached_handler(0x100, &except_vec2_generic, 0x80);
                break;
        }

        probe_pcache();
        setup_scache();

        r4k_blast_dcache_page_setup();
        r4k_blast_dcache_page_indexed_setup();
        r4k_blast_dcache_setup();
        r4k_blast_icache_page_setup();
        r4k_blast_icache_page_indexed_setup();
        r4k_blast_icache_setup();
        r4k_blast_scache_page_setup();
        r4k_blast_scache_page_indexed_setup();
        r4k_blast_scache_setup();

        /*
         * Some MIPS32 and MIPS64 processors have physically indexed caches.
         * This code supports virtually indexed processors and will be
         * unnecessarily inefficient on physically indexed processors.
         */
        if (c->dcache.linesz)
                shm_align_mask = max_t( unsigned long,
                                        c->dcache.sets * c->dcache.linesz - 1,
                                        PAGE_SIZE - 1);
        else
                shm_align_mask = PAGE_SIZE-1;

        __flush_cache_vmap      = r4k__flush_cache_vmap;
        __flush_cache_vunmap    = r4k__flush_cache_vunmap;

        flush_cache_all         = cache_noop;
        __flush_cache_all       = r4k___flush_cache_all;
        flush_cache_mm          = r4k_flush_cache_mm;
        flush_cache_page        = r4k_flush_cache_page;
        flush_cache_range       = r4k_flush_cache_range;

        flush_cache_sigtramp    = r4k_flush_cache_sigtramp;
        flush_icache_all        = r4k_flush_icache_all;
        local_flush_data_cache_page     = local_r4k_flush_data_cache_page;
        flush_data_cache_page   = r4k_flush_data_cache_page;
        flush_icache_range      = r4k_flush_icache_range;

#ifdef CONFIG_DMA_NONCOHERENT
        _dma_cache_wback_inv    = r4k_dma_cache_wback_inv;
        _dma_cache_wback        = r4k_dma_cache_wback_inv;
        _dma_cache_inv          = r4k_dma_cache_inv;
#endif

        build_clear_page();
        build_copy_page();
        local_r4k___flush_cache_all(NULL);
        coherency_setup();
}