Merge tag 'linux-kselftest-kunit-fixes-5.11-rc3' of git://git.kernel.org/pub/scm...

[linux/fpc-iii.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 (davem@davemloft.net)
 * Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Ralf Baechle (ralf@gnu.org)
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#include <linux/cpu_pm.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/export.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/cpu-type.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/r4kcache.h>
#include <asm/sections.h>
#include <asm/mmu_context.h>
#include <asm/war.h>
#include <asm/cacheflush.h> /* for run_uncached() */
#include <asm/traps.h>
#include <asm/dma-coherence.h>
#include <asm/mips-cps.h>

/*
 * Bits describing what cache ops an SMP callback function may perform.
 *
 * R4K_HIT   -  Virtual user or kernel address based cache operations. The
 *              active_mm must be checked before using user addresses, falling
 *              back to kmap.
 * R4K_INDEX -  Index based cache operations.
 */

#define R4K_HIT         BIT(0)
#define R4K_INDEX       BIT(1)

/**
 * r4k_op_needs_ipi() - Decide if a cache op needs to be done on every core.
 * @type:       Type of cache operations (R4K_HIT or R4K_INDEX).
 *
 * Decides whether a cache op needs to be performed on every core in the system.
 * This may change depending on the @type of cache operation, as well as the set
 * of online CPUs, so preemption should be disabled by the caller to prevent CPU
 * hotplug from changing the result.
 *
 * Returns:     1 if the cache operation @type should be done on every core in
 *              the system.
 *              0 if the cache operation @type is globalized and only needs to
 *              be performed on a simple CPU.
 */
static inline bool r4k_op_needs_ipi(unsigned int type)
{
        /* The MIPS Coherence Manager (CM) globalizes address-based cache ops */
        if (type == R4K_HIT && mips_cm_present())
                return false;

        /*
         * Hardware doesn't globalize the required cache ops, so SMP calls may
         * be needed, but only if there are foreign CPUs (non-siblings with
         * separate caches).
         */
        /* cpu_foreign_map[] undeclared when !CONFIG_SMP */
#ifdef CONFIG_SMP
        return !cpumask_empty(&cpu_foreign_map[0]);
#else
        return false;
#endif
}

/*
 * 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.
 *  o doesn't disable interrupts on the local CPU
 */
static inline void r4k_on_each_cpu(unsigned int type,
                                   void (*func)(void *info), void *info)
{
        preempt_disable();
        if (r4k_op_needs_ipi(type))
                smp_call_function_many(&cpu_foreign_map[smp_processor_id()],
                                       func, info, 1);
        func(info);
        preempt_enable();
}

/*
 * Must die.
 */
static unsigned long icache_size __read_mostly;
static unsigned long dcache_size __read_mostly;
static unsigned long vcache_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 (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) &&              \
            cpu_is_r4600_v2_x())                                        \
                *(volatile unsigned long *)CKSEG1;                      \
        if (IS_ENABLED(CONFIG_WAR_R4600_V1_HIT_CACHEOP))                                        \
                __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 inline void r4k_blast_dcache_page_dc64(unsigned long addr)
{
        blast_dcache64_page(addr);
}

static inline void r4k_blast_dcache_page_dc128(unsigned long addr)
{
        blast_dcache128_page(addr);
}

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

        switch (dc_lsize) {
        case 0:
                r4k_blast_dcache_page = (void *)cache_noop;
                break;
        case 16:
                r4k_blast_dcache_page = blast_dcache16_page;
                break;
        case 32:
                r4k_blast_dcache_page = r4k_blast_dcache_page_dc32;
                break;
        case 64:
                r4k_blast_dcache_page = r4k_blast_dcache_page_dc64;
                break;
        case 128:
                r4k_blast_dcache_page = r4k_blast_dcache_page_dc128;
                break;
        default:
                break;
        }
}

#ifndef CONFIG_EVA
#define r4k_blast_dcache_user_page  r4k_blast_dcache_page
#else

static void (*r4k_blast_dcache_user_page)(unsigned long addr);

static void r4k_blast_dcache_user_page_setup(void)
{
        unsigned long  dc_lsize = cpu_dcache_line_size();

        if (dc_lsize == 0)
                r4k_blast_dcache_user_page = (void *)cache_noop;
        else if (dc_lsize == 16)
                r4k_blast_dcache_user_page = blast_dcache16_user_page;
        else if (dc_lsize == 32)
                r4k_blast_dcache_user_page = blast_dcache32_user_page;
        else if (dc_lsize == 64)
                r4k_blast_dcache_user_page = blast_dcache64_user_page;
}

#endif

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

static void 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;
        else if (dc_lsize == 64)
                r4k_blast_dcache_page_indexed = blast_dcache64_page_indexed;
        else if (dc_lsize == 128)
                r4k_blast_dcache_page_indexed = blast_dcache128_page_indexed;
}

void (* r4k_blast_dcache)(void);
EXPORT_SYMBOL(r4k_blast_dcache);

static void 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;
        else if (dc_lsize == 64)
                r4k_blast_dcache = blast_dcache64;
        else if (dc_lsize == 128)
                r4k_blast_dcache = blast_dcache128;
}

/* force code alignment (used for CONFIG_WAR_TX49XX_ICACHE_INDEX_INV) */
#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)
                        cache_unroll(32, kernel_cache, Index_Invalidate_I,
                                     addr | ws, 32);
        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)
                        cache_unroll(32, kernel_cache, Index_Invalidate_I,
                                     addr | ws, 32);
}

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)
                        cache_unroll(32, kernel_cache, Index_Invalidate_I,
                                     addr | ws, 32);
        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)
                        cache_unroll(32, kernel_cache, Index_Invalidate_I,
                                     addr | ws, 32);
}

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

static void 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 && current_cpu_type() == CPU_LOONGSON2EF)
                r4k_blast_icache_page = loongson2_blast_icache32_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;
        else if (ic_lsize == 128)
                r4k_blast_icache_page = blast_icache128_page;
}

#ifndef CONFIG_EVA
#define r4k_blast_icache_user_page  r4k_blast_icache_page
#else

static void (*r4k_blast_icache_user_page)(unsigned long addr);

static void r4k_blast_icache_user_page_setup(void)
{
        unsigned long ic_lsize = cpu_icache_line_size();

        if (ic_lsize == 0)
                r4k_blast_icache_user_page = (void *)cache_noop;
        else if (ic_lsize == 16)
                r4k_blast_icache_user_page = blast_icache16_user_page;
        else if (ic_lsize == 32)
                r4k_blast_icache_user_page = blast_icache32_user_page;
        else if (ic_lsize == 64)
                r4k_blast_icache_user_page = blast_icache64_user_page;
}

#endif

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

static void 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 (IS_ENABLED(CONFIG_WAR_R4600_V1_INDEX_ICACHEOP) &&
                    cpu_is_r4600_v1_x())
                        r4k_blast_icache_page_indexed =
                                blast_icache32_r4600_v1_page_indexed;
                else if (IS_ENABLED(CONFIG_WAR_TX49XX_ICACHE_INDEX_INV))
                        r4k_blast_icache_page_indexed =
                                tx49_blast_icache32_page_indexed;
                else if (current_cpu_type() == CPU_LOONGSON2EF)
                        r4k_blast_icache_page_indexed =
                                loongson2_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;
}

void (* r4k_blast_icache)(void);
EXPORT_SYMBOL(r4k_blast_icache);

static void 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 (IS_ENABLED(CONFIG_WAR_R4600_V1_INDEX_ICACHEOP) &&
                    cpu_is_r4600_v1_x())
                        r4k_blast_icache = blast_r4600_v1_icache32;
                else if (IS_ENABLED(CONFIG_WAR_TX49XX_ICACHE_INDEX_INV))
                        r4k_blast_icache = tx49_blast_icache32;
                else if (current_cpu_type() == CPU_LOONGSON2EF)
                        r4k_blast_icache = loongson2_blast_icache32;
                else
                        r4k_blast_icache = blast_icache32;
        } else if (ic_lsize == 64)
                r4k_blast_icache = blast_icache64;
        else if (ic_lsize == 128)
                r4k_blast_icache = blast_icache128;
}

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

static void 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 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 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 void (*r4k_blast_scache_node)(long node);

static void r4k_blast_scache_node_setup(void)
{
        unsigned long sc_lsize = cpu_scache_line_size();

        if (current_cpu_type() != CPU_LOONGSON64)
                r4k_blast_scache_node = (void *)cache_noop;
        else if (sc_lsize == 16)
                r4k_blast_scache_node = blast_scache16_node;
        else if (sc_lsize == 32)
                r4k_blast_scache_node = blast_scache32_node;
        else if (sc_lsize == 64)
                r4k_blast_scache_node = blast_scache64_node;
        else if (sc_lsize == 128)
                r4k_blast_scache_node = blast_scache128_node;
}

static inline void local_r4k___flush_cache_all(void * args)
{
        switch (current_cpu_type()) {
        case CPU_LOONGSON2EF:
        case CPU_R4000SC:
        case CPU_R4000MC:
        case CPU_R4400SC:
        case CPU_R4400MC:
        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
        case CPU_R16000:
                /*
                 * These caches are inclusive caches, that is, if something
                 * is not cached in the S-cache, we know it also won't be
                 * in one of the primary caches.
                 */
                r4k_blast_scache();
                break;

        case CPU_LOONGSON64:
                /* Use get_ebase_cpunum() for both NUMA=y/n */
                r4k_blast_scache_node(get_ebase_cpunum() >> 2);
                break;

        case CPU_BMIPS5000:
                r4k_blast_scache();
                __sync();
                break;

        default:
                r4k_blast_dcache();
                r4k_blast_icache();
                break;
        }
}

static void r4k___flush_cache_all(void)
{
        r4k_on_each_cpu(R4K_INDEX, local_r4k___flush_cache_all, NULL);
}

/**
 * has_valid_asid() - Determine if an mm already has an ASID.
 * @mm:         Memory map.
 * @type:       R4K_HIT or R4K_INDEX, type of cache op.
 *
 * Determines whether @mm already has an ASID on any of the CPUs which cache ops
 * of type @type within an r4k_on_each_cpu() call will affect. If
 * r4k_on_each_cpu() does an SMP call to a single VPE in each core, then the
 * scope of the operation is confined to sibling CPUs, otherwise all online CPUs
 * will need to be checked.
 *
 * Must be called in non-preemptive context.
 *
 * Returns:     1 if the CPUs affected by @type cache ops have an ASID for @mm.
 *              0 otherwise.
 */
static inline int has_valid_asid(const struct mm_struct *mm, unsigned int type)
{
        unsigned int i;
        const cpumask_t *mask = cpu_present_mask;

        if (cpu_has_mmid)
                return cpu_context(0, mm) != 0;

        /* cpu_sibling_map[] undeclared when !CONFIG_SMP */
#ifdef CONFIG_SMP
        /*
         * If r4k_on_each_cpu does SMP calls, it does them to a single VPE in
         * each foreign core, so we only need to worry about siblings.
         * Otherwise we need to worry about all present CPUs.
         */
        if (r4k_op_needs_ipi(type))
                mask = &cpu_sibling_map[smp_processor_id()];
#endif
        for_each_cpu(i, mask)
                if (cpu_context(i, mm))
                        return 1;
        return 0;
}

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

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

/*
 * Note: flush_tlb_range() assumes flush_cache_range() sufficiently flushes
 * whole caches when vma is executable.
 */
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, R4K_INDEX))
                return;

        /*
         * If dcache can alias, we must blast it since mapping is changing.
         * If executable, we must ensure any dirty lines are written back far
         * enough to be visible to icache.
         */
        if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc))
                r4k_blast_dcache();
        /* If executable, blast stale lines from icache */
        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)
                r4k_on_each_cpu(R4K_INDEX, local_r4k_flush_cache_range, vma);
}

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

        if (!has_valid_asid(mm, R4K_INDEX))
                return;

        /*
         * Kludge alert.  For obscure reasons R4000SC and R4400SC go nuts if we
         * only flush the primary caches but R1x000 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(R4K_INDEX, local_r4k_flush_cache_mm, mm);
}

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;
        int map_coherent = 0;
        pmd_t *pmdp;
        pte_t *ptep;
        void *vaddr;

        /*
         * If owns no valid ASID yet, cannot possibly have gotten
         * this page into the cache.
         */
        if (!has_valid_asid(mm, R4K_HIT))
                return;

        addr &= PAGE_MASK;
        pmdp = pmd_off(mm, addr);
        ptep = pte_offset_kernel(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.
                 */
                map_coherent = (cpu_has_dc_aliases &&
                                page_mapcount(page) &&
                                !Page_dcache_dirty(page));
                if (map_coherent)
                        vaddr = kmap_coherent(page, addr);
                else
                        vaddr = kmap_atomic(page);
                addr = (unsigned long)vaddr;
        }

        if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
                vaddr ? r4k_blast_dcache_page(addr) :
                        r4k_blast_dcache_user_page(addr);
                if (exec && !cpu_icache_snoops_remote_store)
                        r4k_blast_scache_page(addr);
        }
        if (exec) {
                if (vaddr && cpu_has_vtag_icache && mm == current->active_mm) {
                        drop_mmu_context(mm);
                } else
                        vaddr ? r4k_blast_icache_page(addr) :
                                r4k_blast_icache_user_page(addr);
        }

        if (vaddr) {
                if (map_coherent)
                        kunmap_coherent();
                else
                        kunmap_atomic(vaddr);
        }
}

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(R4K_HIT, local_r4k_flush_cache_page, &args);
}

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(R4K_HIT, local_r4k_flush_data_cache_page,
                                (void *) addr);
}

struct flush_icache_range_args {
        unsigned long start;
        unsigned long end;
        unsigned int type;
        bool user;
};

static inline void __local_r4k_flush_icache_range(unsigned long start,
                                                  unsigned long end,
                                                  unsigned int type,
                                                  bool user)
{
        if (!cpu_has_ic_fills_f_dc) {
                if (type == R4K_INDEX ||
                    (type & R4K_INDEX && end - start >= dcache_size)) {
                        r4k_blast_dcache();
                } else {
                        R4600_HIT_CACHEOP_WAR_IMPL;
                        if (user)
                                protected_blast_dcache_range(start, end);
                        else
                                blast_dcache_range(start, end);
                }
        }

        if (type == R4K_INDEX ||
            (type & R4K_INDEX && end - start > icache_size))
                r4k_blast_icache();
        else {
                switch (boot_cpu_type()) {
                case CPU_LOONGSON2EF:
                        protected_loongson2_blast_icache_range(start, end);
                        break;

                default:
                        if (user)
                                protected_blast_icache_range(start, end);
                        else
                                blast_icache_range(start, end);
                        break;
                }
        }
}

static inline void local_r4k_flush_icache_range(unsigned long start,
                                                unsigned long end)
{
        __local_r4k_flush_icache_range(start, end, R4K_HIT | R4K_INDEX, false);
}

static inline void local_r4k_flush_icache_user_range(unsigned long start,
                                                     unsigned long end)
{
        __local_r4k_flush_icache_range(start, end, R4K_HIT | R4K_INDEX, true);
}

static inline void local_r4k_flush_icache_range_ipi(void *args)
{
        struct flush_icache_range_args *fir_args = args;
        unsigned long start = fir_args->start;
        unsigned long end = fir_args->end;
        unsigned int type = fir_args->type;
        bool user = fir_args->user;

        __local_r4k_flush_icache_range(start, end, type, user);
}

static void __r4k_flush_icache_range(unsigned long start, unsigned long end,
                                     bool user)
{
        struct flush_icache_range_args args;
        unsigned long size, cache_size;

        args.start = start;
        args.end = end;
        args.type = R4K_HIT | R4K_INDEX;
        args.user = user;

        /*
         * Indexed cache ops require an SMP call.
         * Consider if that can or should be avoided.
         */
        preempt_disable();
        if (r4k_op_needs_ipi(R4K_INDEX) && !r4k_op_needs_ipi(R4K_HIT)) {
                /*
                 * If address-based cache ops don't require an SMP call, then
                 * use them exclusively for small flushes.
                 */
                size = end - start;
                cache_size = icache_size;
                if (!cpu_has_ic_fills_f_dc) {
                        size *= 2;
                        cache_size += dcache_size;
                }
                if (size <= cache_size)
                        args.type &= ~R4K_INDEX;
        }
        r4k_on_each_cpu(args.type, local_r4k_flush_icache_range_ipi, &args);
        preempt_enable();
        instruction_hazard();
}

static void r4k_flush_icache_range(unsigned long start, unsigned long end)
{
        return __r4k_flush_icache_range(start, end, false);
}

static void r4k_flush_icache_user_range(unsigned long start, unsigned long end)
{
        return __r4k_flush_icache_range(start, end, true);
}

#ifdef CONFIG_DMA_NONCOHERENT

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

        preempt_disable();
        if (cpu_has_inclusive_pcaches) {
                if (size >= scache_size) {
                        if (current_cpu_type() != CPU_LOONGSON64)
                                r4k_blast_scache();
                        else
                                r4k_blast_scache_node(pa_to_nid(addr));
                } else {
                        blast_scache_range(addr, addr + size);
                }
                preempt_enable();
                __sync();
                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 we would need IPI to perform an INDEX-type operation, then
         * we have to use the HIT-type alternative as IPI cannot be used
         * here due to interrupts possibly being disabled.
         */
        if (!r4k_op_needs_ipi(R4K_INDEX) && size >= dcache_size) {
                r4k_blast_dcache();
        } else {
                R4600_HIT_CACHEOP_WAR_IMPL;
                blast_dcache_range(addr, addr + size);
        }
        preempt_enable();

        bc_wback_inv(addr, size);
        __sync();
}

static void prefetch_cache_inv(unsigned long addr, unsigned long size)
{
        unsigned int linesz = cpu_scache_line_size();
        unsigned long addr0 = addr, addr1;

        addr0 &= ~(linesz - 1);
        addr1 = (addr0 + size - 1) & ~(linesz - 1);

        protected_writeback_scache_line(addr0);
        if (likely(addr1 != addr0))
                protected_writeback_scache_line(addr1);
        else
                return;

        addr0 += linesz;
        if (likely(addr1 != addr0))
                protected_writeback_scache_line(addr0);
        else
                return;

        addr1 -= linesz;
        if (likely(addr1 > addr0))
                protected_writeback_scache_line(addr0);
}

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

        preempt_disable();

        if (current_cpu_type() == CPU_BMIPS5000)
                prefetch_cache_inv(addr, size);

        if (cpu_has_inclusive_pcaches) {
                if (size >= scache_size) {
                        if (current_cpu_type() != CPU_LOONGSON64)
                                r4k_blast_scache();
                        else
                                r4k_blast_scache_node(pa_to_nid(addr));
                } else {
                        /*
                         * There is no clearly documented alignment requirement
                         * for the cache instruction on MIPS processors and
                         * some processors, among them the RM5200 and RM7000
                         * QED processors will throw an address error for cache
                         * hit ops with insufficient alignment.  Solved by
                         * aligning the address to cache line size.
                         */
                        blast_inv_scache_range(addr, addr + size);
                }
                preempt_enable();
                __sync();
                return;
        }

        if (!r4k_op_needs_ipi(R4K_INDEX) && size >= dcache_size) {
                r4k_blast_dcache();
        } else {
                R4600_HIT_CACHEOP_WAR_IMPL;
                blast_inv_dcache_range(addr, addr + size);
        }
        preempt_enable();

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

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

struct flush_kernel_vmap_range_args {
        unsigned long   vaddr;
        int             size;
};

static inline void local_r4k_flush_kernel_vmap_range_index(void *args)
{
        /*
         * Aliases only affect the primary caches so don't bother with
         * S-caches or T-caches.
         */
        r4k_blast_dcache();
}

static inline void local_r4k_flush_kernel_vmap_range(void *args)
{
        struct flush_kernel_vmap_range_args *vmra = args;
        unsigned long vaddr = vmra->vaddr;
        int size = vmra->size;

        /*
         * Aliases only affect the primary caches so don't bother with
         * S-caches or T-caches.
         */
        R4600_HIT_CACHEOP_WAR_IMPL;
        blast_dcache_range(vaddr, vaddr + size);
}

static void r4k_flush_kernel_vmap_range(unsigned long vaddr, int size)
{
        struct flush_kernel_vmap_range_args args;

        args.vaddr = (unsigned long) vaddr;
        args.size = size;

        if (size >= dcache_size)
                r4k_on_each_cpu(R4K_INDEX,
                                local_r4k_flush_kernel_vmap_range_index, NULL);
        else
                r4k_on_each_cpu(R4K_HIT, local_r4k_flush_kernel_vmap_range,
                                &args);
}

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_I));
        }
}

static inline int alias_74k_erratum(struct cpuinfo_mips *c)
{
        unsigned int imp = c->processor_id & PRID_IMP_MASK;
        unsigned int rev = c->processor_id & PRID_REV_MASK;
        int present = 0;

        /*
         * Early versions of the 74K do not update the cache tags on a
         * vtag miss/ptag hit which can occur in the case of KSEG0/KUSEG
         * aliases.  In this case it is better to treat the cache as always
         * having aliases.  Also disable the synonym tag update feature
         * where available.  In this case no opportunistic tag update will
         * happen where a load causes a virtual address miss but a physical
         * address hit during a D-cache look-up.
         */
        switch (imp) {
        case PRID_IMP_74K:
                if (rev <= PRID_REV_ENCODE_332(2, 4, 0))
                        present = 1;
                if (rev == PRID_REV_ENCODE_332(2, 4, 0))
                        write_c0_config6(read_c0_config6() | MTI_CONF6_SYND);
                break;
        case PRID_IMP_1074K:
                if (rev <= PRID_REV_ENCODE_332(1, 1, 0)) {
                        present = 1;
                        write_c0_config6(read_c0_config6() | MTI_CONF6_SYND);
                }
                break;
        default:
                BUG();
        }

        return present;
}

static void b5k_instruction_hazard(void)
{
        __sync();
        __sync();
        __asm__ __volatile__(
        "       nop; nop; nop; nop; nop; nop; nop; nop\n"
        "       nop; nop; nop; nop; nop; nop; nop; nop\n"
        "       nop; nop; nop; nop; nop; nop; nop; nop\n"
        "       nop; nop; nop; nop; nop; nop; nop; nop\n"
        : : : "memory");
}

static char *way_string[] = { NULL, "direct mapped", "2-way",
        "3-way", "4-way", "5-way", "6-way", "7-way", "8-way",
        "9-way", "10-way", "11-way", "12-way",
        "13-way", "14-way", "15-way", "16-way",
};

static void probe_pcache(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int config = read_c0_config();
        unsigned int prid = read_c0_prid();
        int has_74k_erratum = 0;
        unsigned long config1;
        unsigned int lsize;

        switch (current_cpu_type()) {
        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_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 | MIPS_CPU_PREFETCH;
                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:
                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:
        case CPU_R16000:
                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);
                fallthrough;
        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();

                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);

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

        case CPU_LOONGSON2EF:
                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;

        case CPU_LOONGSON64:
                config1 = read_c0_config1();
                lsize = (config1 >> 19) & 7;
                if (lsize)
                        c->icache.linesz = 2 << lsize;
                else
                        c->icache.linesz = 0;
                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 = 0;

                lsize = (config1 >> 10) & 7;
                if (lsize)
                        c->dcache.linesz = 2 << lsize;
                else
                        c->dcache.linesz = 0;
                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 = 0;
                if ((c->processor_id & (PRID_IMP_MASK | PRID_REV_MASK)) >=
                                (PRID_IMP_LOONGSON_64C | PRID_REV_LOONGSON3A_R2_0) ||
                                (c->processor_id & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64R)
                        c->options |= MIPS_CPU_PREFETCH;
                break;

        case CPU_CAVIUM_OCTEON3:
                /* For now lie about the number of ways. */
                c->icache.linesz = 128;
                c->icache.sets = 16;
                c->icache.ways = 8;
                c->icache.flags |= MIPS_CACHE_VTAG;
                icache_size = c->icache.sets * c->icache.ways * c->icache.linesz;

                c->dcache.linesz = 128;
                c->dcache.ways = 8;
                c->dcache.sets = 8;
                dcache_size = c->dcache.sets * c->dcache.ways * c->dcache.linesz;
                c->options |= MIPS_CPU_PREFETCH;
                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();

                lsize = (config1 >> 19) & 7;

                /* IL == 7 is reserved */
                if (lsize == 7)
                        panic("Invalid icache line size");

                c->icache.linesz = lsize ? 2 << lsize : 0;

                c->icache.sets = 32 << (((config1 >> 22) + 1) & 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 & MIPS_CONF_VI)
                        c->icache.flags |= MIPS_CACHE_VTAG;

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

                lsize = (config1 >> 10) & 7;

                /* DL == 7 is reserved */
                if (lsize == 7)
                        panic("Invalid dcache line size");

                c->dcache.linesz = lsize ? 2 << lsize : 0;

                c->dcache.sets = 32 << (((config1 >> 13) + 1) & 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 & PRID_IMP_MASK) == PRID_IMP_R4000 &&
            (prid & PRID_REV_MASK) < PRID_REV_R4400 &&
            !(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;

        /*
         * R1x000 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 (current_cpu_type()) {
        case CPU_20KC:
        case CPU_25KF:
        case CPU_I6400:
        case CPU_I6500:
        case CPU_SB1:
        case CPU_SB1A:
        case CPU_XLR:
                c->dcache.flags |= MIPS_CACHE_PINDEX;
                break;

        case CPU_R10000:
        case CPU_R12000:
        case CPU_R14000:
        case CPU_R16000:
                break;

        case CPU_74K:
        case CPU_1074K:
                has_74k_erratum = alias_74k_erratum(c);
                fallthrough;
        case CPU_M14KC:
        case CPU_M14KEC:
        case CPU_24K:
        case CPU_34K:
        case CPU_1004K:
        case CPU_INTERAPTIV:
        case CPU_P5600:
        case CPU_PROAPTIV:
        case CPU_M5150:
        case CPU_QEMU_GENERIC:
        case CPU_P6600:
        case CPU_M6250:
                if (!(read_c0_config7() & MIPS_CONF7_IAR) &&
                    (c->icache.waysize > PAGE_SIZE))
                        c->icache.flags |= MIPS_CACHE_ALIASES;
                if (!has_74k_erratum && (read_c0_config7() & MIPS_CONF7_AR)) {
                        /*
                         * Effectively physically indexed dcache,
                         * thus no virtual aliases.
                        */
                        c->dcache.flags |= MIPS_CACHE_PINDEX;
                        break;
                }
                fallthrough;
        default:
                if (has_74k_erratum || c->dcache.waysize > PAGE_SIZE)
                        c->dcache.flags |= MIPS_CACHE_ALIASES;
        }

        /* Physically indexed caches don't suffer from virtual aliasing */
        if (c->dcache.flags & MIPS_CACHE_PINDEX)
                c->dcache.flags &= ~MIPS_CACHE_ALIASES;

        /*
         * In systems with CM the icache fills from L2 or closer caches, and
         * thus sees remote stores without needing to write them back any
         * further than that.
         */
        if (mips_cm_present())
                c->icache.flags |= MIPS_IC_SNOOPS_REMOTE;

        switch (current_cpu_type()) {
        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_ALCHEMY:
        case CPU_I6400:
        case CPU_I6500:
                c->icache.flags |= MIPS_CACHE_IC_F_DC;
                break;

        case CPU_BMIPS5000:
                c->icache.flags |= MIPS_CACHE_IC_F_DC;
                /* Cache aliases are handled in hardware; allow HIGHMEM */
                c->dcache.flags &= ~MIPS_CACHE_ALIASES;
                break;

        case CPU_LOONGSON2EF:
                /*
                 * LOONGSON2 has 4 way icache, but when using indexed cache op,
                 * one op will act on all 4 ways
                 */
                c->icache.ways = 1;
        }

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

        pr_info("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);
}

static void probe_vcache(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int config2, lsize;

        if (current_cpu_type() != CPU_LOONGSON64)
                return;

        config2 = read_c0_config2();
        if ((lsize = ((config2 >> 20) & 15)))
                c->vcache.linesz = 2 << lsize;
        else
                c->vcache.linesz = lsize;

        c->vcache.sets = 64 << ((config2 >> 24) & 15);
        c->vcache.ways = 1 + ((config2 >> 16) & 15);

        vcache_size = c->vcache.sets * c->vcache.ways * c->vcache.linesz;

        c->vcache.waybit = 0;
        c->vcache.waysize = vcache_size / c->vcache.ways;

        pr_info("Unified victim cache %ldkB %s, linesize %d bytes.\n",
                vcache_size >> 10, way_string[c->vcache.ways], c->vcache.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 probe_scache(void)
{
        unsigned long flags, addr, begin, end, pow2;
        unsigned int config = read_c0_config();
        struct cpuinfo_mips *c = &current_cpu_data;

        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);
        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->scache.waybit = 0;           /* does not matter */

        return 1;
}

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;
}

static void loongson3_sc_init(void)
{
        struct cpuinfo_mips *c = &current_cpu_data;
        unsigned int config2, lsize;

        config2 = read_c0_config2();
        lsize = (config2 >> 4) & 15;
        if (lsize)
                c->scache.linesz = 2 << lsize;
        else
                c->scache.linesz = 0;
        c->scache.sets = 64 << ((config2 >> 8) & 15);
        c->scache.ways = 1 + (config2 & 15);

        /* Loongson-3 has 4-Scache banks, while Loongson-2K have only 2 banks */
        if ((c->processor_id & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64R)
                c->scache.sets *= 2;
        else
                c->scache.sets *= 4;

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

        c->scache.waybit = 0;
        c->scache.waysize = scache_size / 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);
        if (scache_size)
                c->options |= MIPS_CPU_INCLUSIVE_CACHES;
        return;
}

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

static void 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 (current_cpu_type()) {
        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:
        case CPU_R16000:
                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:
#ifdef CONFIG_RM7000_CPU_SCACHE
                rm7k_sc_init();
#endif
                return;

        case CPU_LOONGSON2EF:
                loongson2_sc_init();
                return;

        case CPU_LOONGSON64:
                loongson3_sc_init();
                return;

        case CPU_CAVIUM_OCTEON3:
        case CPU_XLP:
                /* don't need to worry about L2, fully coherent */
                return;

        default:
                if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
                                    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
                                    MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
                                    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
#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);

                                if (current_cpu_type() == CPU_BMIPS5000)
                                        c->options |= MIPS_CPU_INCLUSIVE_CACHES;
                        }

#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 the (now gone) cpu table.
         */
        case 0x02030200: /* Au1100 AB */
        case 0x02030201: /* Au1100 BA */
        case 0x02030202: /* Au1100 BC */
                set_c0_config(1 << 19);
                break;
        }
}

/* CP0 hazard avoidance. */
#define NXP_BARRIER()                                                   \
         __asm__ __volatile__(                                          \
        ".set noreorder\n\t"                                            \
        "nop; nop; nop; nop; nop; nop;\n\t"                             \
        ".set reorder\n\t")

static void nxp_pr4450_fixup_config(void)
{
        unsigned long config0;

        config0 = read_c0_config();

        /* clear all three cache coherency fields */
        config0 &= ~(0x7 | (7 << 25) | (7 << 28));
        config0 |= (((_page_cachable_default >> _CACHE_SHIFT) <<  0) |
                    ((_page_cachable_default >> _CACHE_SHIFT) << 25) |
                    ((_page_cachable_default >> _CACHE_SHIFT) << 28));
        write_c0_config(config0);
        NXP_BARRIER();
}

static int cca = -1;

static int __init cca_setup(char *str)
{
        get_option(&str, &cca);

        return 0;
}

early_param("cca", cca_setup);

static void coherency_setup(void)
{
        if (cca < 0 || cca > 7)
                cca = read_c0_config() & CONF_CM_CMASK;
        _page_cachable_default = cca << _CACHE_SHIFT;

        pr_debug("Using cache attribute %d\n", cca);
        change_c0_config(CONF_CM_CMASK, cca);

        /*
         * 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 on:
         * Au1000 rev DA, HA, HB;  Au1100 AB, BA, BC, Au1500 AB
         */
        case CPU_ALCHEMY:
                au1x00_fixup_config_od();
                break;

        case PRID_IMP_PR4450:
                nxp_pr4450_fixup_config();
                break;
        }
}

static void r4k_cache_error_setup(void)
{
        extern char __weak except_vec2_generic;
        extern char __weak except_vec2_sb1;

        switch (current_cpu_type()) {
        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;
        }
}

void r4k_cache_init(void)
{
        extern void build_clear_page(void);
        extern void build_copy_page(void);
        struct cpuinfo_mips *c = &current_cpu_data;

        probe_pcache();
        probe_vcache();
        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();
        r4k_blast_scache_node_setup();
#ifdef CONFIG_EVA
        r4k_blast_dcache_user_page_setup();
        r4k_blast_icache_user_page_setup();
#endif

        /*
         * 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 && cpu_has_dc_aliases)
                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_kernel_vmap_range = r4k_flush_kernel_vmap_range;

        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;
        local_flush_icache_range        = local_r4k_flush_icache_range;
        __flush_icache_user_range       = r4k_flush_icache_user_range;
        __local_flush_icache_user_range = local_r4k_flush_icache_user_range;

#ifdef CONFIG_DMA_NONCOHERENT
#ifdef CONFIG_DMA_MAYBE_COHERENT
        if (coherentio == IO_COHERENCE_ENABLED ||
            (coherentio == IO_COHERENCE_DEFAULT && hw_coherentio)) {
                _dma_cache_wback_inv    = (void *)cache_noop;
                _dma_cache_wback        = (void *)cache_noop;
                _dma_cache_inv          = (void *)cache_noop;
        } else
#endif /* CONFIG_DMA_MAYBE_COHERENT */
        {
                _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 /* CONFIG_DMA_NONCOHERENT */

        build_clear_page();
        build_copy_page();

        /*
         * We want to run CMP kernels on core with and without coherent
         * caches. Therefore, do not use CONFIG_MIPS_CMP to decide whether
         * or not to flush caches.
         */
        local_r4k___flush_cache_all(NULL);

        coherency_setup();
        board_cache_error_setup = r4k_cache_error_setup;

        /*
         * Per-CPU overrides
         */
        switch (current_cpu_type()) {
        case CPU_BMIPS4350:
        case CPU_BMIPS4380:
                /* No IPI is needed because all CPUs share the same D$ */
                flush_data_cache_page = r4k_blast_dcache_page;
                break;
        case CPU_BMIPS5000:
                /* We lose our superpowers if L2 is disabled */
                if (c->scache.flags & MIPS_CACHE_NOT_PRESENT)
                        break;

                /* I$ fills from D$ just by emptying the write buffers */
                flush_cache_page = (void *)b5k_instruction_hazard;
                flush_cache_range = (void *)b5k_instruction_hazard;
                local_flush_data_cache_page = (void *)b5k_instruction_hazard;
                flush_data_cache_page = (void *)b5k_instruction_hazard;
                flush_icache_range = (void *)b5k_instruction_hazard;
                local_flush_icache_range = (void *)b5k_instruction_hazard;


                /* Optimization: an L2 flush implicitly flushes the L1 */
                current_cpu_data.options |= MIPS_CPU_INCLUSIVE_CACHES;
                break;
        case CPU_LOONGSON64:
                /* Loongson-3 maintains cache coherency by hardware */
                __flush_cache_all       = cache_noop;
                __flush_cache_vmap      = cache_noop;
                __flush_cache_vunmap    = cache_noop;
                __flush_kernel_vmap_range = (void *)cache_noop;
                flush_cache_mm          = (void *)cache_noop;
                flush_cache_page        = (void *)cache_noop;
                flush_cache_range       = (void *)cache_noop;
                flush_icache_all        = (void *)cache_noop;
                flush_data_cache_page   = (void *)cache_noop;
                local_flush_data_cache_page     = (void *)cache_noop;
                break;
        }
}

static int r4k_cache_pm_notifier(struct notifier_block *self, unsigned long cmd,
                               void *v)
{
        switch (cmd) {
        case CPU_PM_ENTER_FAILED:
        case CPU_PM_EXIT:
                coherency_setup();
                break;
        }

        return NOTIFY_OK;
}

static struct notifier_block r4k_cache_pm_notifier_block = {
        .notifier_call = r4k_cache_pm_notifier,
};

int __init r4k_cache_init_pm(void)
{
        return cpu_pm_register_notifier(&r4k_cache_pm_notifier_block);
}
arch_initcall(r4k_cache_init_pm);