cache-sh2a.c

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/*
 * arch/sh/mm/cache-sh2a.c
 *
 * Copyright (C) 2008 Yoshinori Sato
 *
 * Released under the terms of the GNU GPL v2.0.
 */

#include <linux/init.h>
#include <linux/mm.h>

#include <asm/cache.h>
#include <asm/addrspace.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/io.h>

/*
 * The maximum number of pages we support up to when doing ranged dcache
 * flushing. Anything exceeding this will simply flush the dcache in its
 * entirety.
 */
#define MAX_OCACHE_PAGES    32
#define MAX_ICACHE_PAGES    32

#ifdef CONFIG_CACHE_WRITEBACK
static void sh2a_flush_oc_line(unsigned long v, int way)
{
    unsigned long addr = (v & 0x000007f0) | (way << 11);
    unsigned long data;

    data = __raw_readl(CACHE_OC_ADDRESS_ARRAY | addr);
    if ((data & CACHE_PHYSADDR_MASK) == (v & CACHE_PHYSADDR_MASK)) {
        data &= ~SH_CACHE_UPDATED;
        __raw_writel(data, CACHE_OC_ADDRESS_ARRAY | addr);
    }
}
#endif

static void sh2a_invalidate_line(unsigned long cache_addr, unsigned long v)
{
    /* Set associative bit to hit all ways */
    unsigned long addr = (v & 0x000007f0) | SH_CACHE_ASSOC;
    __raw_writel((addr & CACHE_PHYSADDR_MASK), cache_addr | addr);
}

/*
 * Write back the dirty D-caches, but not invalidate them.
 */
static void sh2a__flush_wback_region(void *start, int size)
{
#ifdef CONFIG_CACHE_WRITEBACK
    unsigned long v;
    unsigned long begin, end;
    unsigned long flags;
    int nr_ways;

    begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
    end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
        & ~(L1_CACHE_BYTES-1);
    nr_ways = current_cpu_data.dcache.ways;

    local_irq_save(flags);
    jump_to_uncached();

    /* If there are too many pages then flush the entire cache */
    if (((end - begin) >> PAGE_SHIFT) >= MAX_OCACHE_PAGES) {
        begin = CACHE_OC_ADDRESS_ARRAY;
        end = begin + (nr_ways * current_cpu_data.dcache.way_size);

        for (v = begin; v < end; v += L1_CACHE_BYTES) {
            unsigned long data = __raw_readl(v);
            if (data & SH_CACHE_UPDATED)
                __raw_writel(data & ~SH_CACHE_UPDATED, v);
        }
    } else {
        int way;
        for (way = 0; way < nr_ways; way++) {
            for (v = begin; v < end; v += L1_CACHE_BYTES)
                sh2a_flush_oc_line(v, way);
        }
    }

    back_to_cached();
    local_irq_restore(flags);
#endif
}

/*
 * Write back the dirty D-caches and invalidate them.
 */
static void sh2a__flush_purge_region(void *start, int size)
{
    unsigned long v;
    unsigned long begin, end;
    unsigned long flags;

    begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
    end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
        & ~(L1_CACHE_BYTES-1);

    local_irq_save(flags);
    jump_to_uncached();

    for (v = begin; v < end; v+=L1_CACHE_BYTES) {
#ifdef CONFIG_CACHE_WRITEBACK
        int way;
        int nr_ways = current_cpu_data.dcache.ways;
        for (way = 0; way < nr_ways; way++)
            sh2a_flush_oc_line(v, way);
#endif
        sh2a_invalidate_line(CACHE_OC_ADDRESS_ARRAY, v);
    }

    back_to_cached();
    local_irq_restore(flags);
}

/*
 * Invalidate the D-caches, but no write back please
 */
static void sh2a__flush_invalidate_region(void *start, int size)
{
    unsigned long v;
    unsigned long begin, end;
    unsigned long flags;

    begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
    end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
        & ~(L1_CACHE_BYTES-1);

    local_irq_save(flags);
    jump_to_uncached();

    /* If there are too many pages then just blow the cache */
    if (((end - begin) >> PAGE_SHIFT) >= MAX_OCACHE_PAGES) {
        __raw_writel(__raw_readl(CCR) | CCR_OCACHE_INVALIDATE, CCR);
    } else {
        for (v = begin; v < end; v += L1_CACHE_BYTES)
            sh2a_invalidate_line(CACHE_OC_ADDRESS_ARRAY, v);
    }

    back_to_cached();
    local_irq_restore(flags);
}

/*
 * Write back the range of D-cache, and purge the I-cache.
 */
static void sh2a_flush_icache_range(void *args)
{
    struct flusher_data *data = args;
    unsigned long start, end;
    unsigned long v;
    unsigned long flags;

    start = data->addr1 & ~(L1_CACHE_BYTES-1);
    end = (data->addr2 + L1_CACHE_BYTES-1) & ~(L1_CACHE_BYTES-1);

#ifdef CONFIG_CACHE_WRITEBACK
    sh2a__flush_wback_region((void *)start, end-start);
#endif

    local_irq_save(flags);
    jump_to_uncached();

    /* I-Cache invalidate */
    /* If there are too many pages then just blow the cache */
    if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
        __raw_writel(__raw_readl(CCR) | CCR_ICACHE_INVALIDATE, CCR);
    } else {
        for (v = start; v < end; v += L1_CACHE_BYTES)
            sh2a_invalidate_line(CACHE_IC_ADDRESS_ARRAY, v);
    }

    back_to_cached();
    local_irq_restore(flags);
}

void __init sh2a_cache_init(void)
{
    local_flush_icache_range    = sh2a_flush_icache_range;

    __flush_wback_region        = sh2a__flush_wback_region;
    __flush_purge_region        = sh2a__flush_purge_region;
    __flush_invalidate_region   = sh2a__flush_invalidate_region;
}