cache-debugfs.c

Go to the documentation of this file.

/*
 * debugfs ops for the L1 cache
 *
 *  Copyright (C) 2006  Paul Mundt
 *
 * 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.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/cache.h>
#include <asm/io.h>

enum cache_type {
    CACHE_TYPE_ICACHE,
    CACHE_TYPE_DCACHE,
    CACHE_TYPE_UNIFIED,
};

static int cache_seq_show(struct seq_file *file, void *iter)
{
    unsigned int cache_type = (unsigned int)file->private;
    struct cache_info *cache;
    unsigned int waysize, way;
    unsigned long ccr;
    unsigned long addrstart = 0;

    /*
     * Go uncached immediately so we don't skew the results any
     * more than we already are..
     */
    jump_to_uncached();

    ccr = __raw_readl(CCR);
    if ((ccr & CCR_CACHE_ENABLE) == 0) {
        back_to_cached();

        seq_printf(file, "disabled\n");
        return 0;
    }

    if (cache_type == CACHE_TYPE_DCACHE) {
        addrstart = CACHE_OC_ADDRESS_ARRAY;
        cache = &current_cpu_data.dcache;
    } else {
        addrstart = CACHE_IC_ADDRESS_ARRAY;
        cache = &current_cpu_data.icache;
    }

    waysize = cache->sets;

    /*
     * If the OC is already in RAM mode, we only have
     * half of the entries to consider..
     */
    if ((ccr & CCR_CACHE_ORA) && cache_type == CACHE_TYPE_DCACHE)
        waysize >>= 1;

    waysize <<= cache->entry_shift;

    for (way = 0; way < cache->ways; way++) {
        unsigned long addr;
        unsigned int line;

        seq_printf(file, "-----------------------------------------\n");
        seq_printf(file, "Way %d\n", way);
        seq_printf(file, "-----------------------------------------\n");

        for (addr = addrstart, line = 0;
             addr < addrstart + waysize;
             addr += cache->linesz, line++) {
            unsigned long data = __raw_readl(addr);

            /* Check the V bit, ignore invalid cachelines */
            if ((data & 1) == 0)
                continue;

            /* U: Dirty, cache tag is 10 bits up */
            seq_printf(file, "%3d: %c 0x%lx\n",
                   line, data & 2 ? 'U' : ' ',
                   data & 0x1ffffc00);
        }

        addrstart += cache->way_incr;
    }

    back_to_cached();

    return 0;
}

static int cache_debugfs_open(struct inode *inode, struct file *file)
{
    return single_open(file, cache_seq_show, inode->i_private);
}

static const struct file_operations cache_debugfs_fops = {
    .owner      = THIS_MODULE,
    .open       = cache_debugfs_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

static int __init cache_debugfs_init(void)
{
    struct dentry *dcache_dentry, *icache_dentry;

    dcache_dentry = debugfs_create_file("dcache", S_IRUSR, arch_debugfs_dir,
                        (unsigned int *)CACHE_TYPE_DCACHE,
                        &cache_debugfs_fops);
    if (!dcache_dentry)
        return -ENOMEM;

    icache_dentry = debugfs_create_file("icache", S_IRUSR, arch_debugfs_dir,
                        (unsigned int *)CACHE_TYPE_ICACHE,
                        &cache_debugfs_fops);
    if (!icache_dentry) {
        debugfs_remove(dcache_dentry);
        return -ENOMEM;
    }

    return 0;
}
module_init(cache_debugfs_init);

MODULE_LICENSE("GPL v2");