tlb-debugfs.c

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/*
 * arch/sh/mm/tlb-debugfs.c
 *
 * debugfs ops for SH-4 ITLB/UTLBs.
 *
 * Copyright (C) 2010  Matt Fleming
 *
 * 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/mmu_context.h>
#include <asm/tlbflush.h>

enum tlb_type {
    TLB_TYPE_ITLB,
    TLB_TYPE_UTLB,
};

static struct {
    int bits;
    const char *size;
} tlb_sizes[] = {
    { 0x0, "  1KB" },
    { 0x1, "  4KB" },
    { 0x2, "  8KB" },
    { 0x4, " 64KB" },
    { 0x5, "256KB" },
    { 0x7, "  1MB" },
    { 0x8, "  4MB" },
    { 0xc, " 64MB" },
};

static int tlb_seq_show(struct seq_file *file, void *iter)
{
    unsigned int tlb_type = (unsigned int)file->private;
    unsigned long addr1, addr2, data1, data2;
    unsigned long flags;
    unsigned long mmucr;
    unsigned int nentries, entry;
    unsigned int urb;

    mmucr = __raw_readl(MMUCR);
    if ((mmucr & 0x1) == 0) {
        seq_printf(file, "address translation disabled\n");
        return 0;
    }

    if (tlb_type == TLB_TYPE_ITLB) {
        addr1 = MMU_ITLB_ADDRESS_ARRAY;
        addr2 = MMU_ITLB_ADDRESS_ARRAY2;
        data1 = MMU_ITLB_DATA_ARRAY;
        data2 = MMU_ITLB_DATA_ARRAY2;
        nentries = 4;
    } else {
        addr1 = MMU_UTLB_ADDRESS_ARRAY;
        addr2 = MMU_UTLB_ADDRESS_ARRAY2;
        data1 = MMU_UTLB_DATA_ARRAY;
        data2 = MMU_UTLB_DATA_ARRAY2;
        nentries = 64;
    }

    local_irq_save(flags);
    jump_to_uncached();

    urb = (mmucr & MMUCR_URB) >> MMUCR_URB_SHIFT;

    /* Make the "entry >= urb" test fail. */
    if (urb == 0)
        urb = MMUCR_URB_NENTRIES + 1;

    if (tlb_type == TLB_TYPE_ITLB) {
        addr1 = MMU_ITLB_ADDRESS_ARRAY;
        addr2 = MMU_ITLB_ADDRESS_ARRAY2;
        data1 = MMU_ITLB_DATA_ARRAY;
        data2 = MMU_ITLB_DATA_ARRAY2;
        nentries = 4;
    } else {
        addr1 = MMU_UTLB_ADDRESS_ARRAY;
        addr2 = MMU_UTLB_ADDRESS_ARRAY2;
        data1 = MMU_UTLB_DATA_ARRAY;
        data2 = MMU_UTLB_DATA_ARRAY2;
        nentries = 64;
    }

    seq_printf(file, "entry:     vpn        ppn     asid  size valid wired\n");

    for (entry = 0; entry < nentries; entry++) {
        unsigned long vpn, ppn, asid, size;
        unsigned long valid;
        unsigned long val;
        const char *sz = "    ?";
        int i;

        val = __raw_readl(addr1 | (entry << MMU_TLB_ENTRY_SHIFT));
        ctrl_barrier();
        vpn = val & 0xfffffc00;
        valid = val & 0x100;

        val = __raw_readl(addr2 | (entry << MMU_TLB_ENTRY_SHIFT));
        ctrl_barrier();
        asid = val & MMU_CONTEXT_ASID_MASK;

        val = __raw_readl(data1 | (entry << MMU_TLB_ENTRY_SHIFT));
        ctrl_barrier();
        ppn = (val & 0x0ffffc00) << 4;

        val = __raw_readl(data2 | (entry << MMU_TLB_ENTRY_SHIFT));
        ctrl_barrier();
        size = (val & 0xf0) >> 4;

        for (i = 0; i < ARRAY_SIZE(tlb_sizes); i++) {
            if (tlb_sizes[i].bits == size)
                break;
        }

        if (i != ARRAY_SIZE(tlb_sizes))
            sz = tlb_sizes[i].size;

        seq_printf(file, "%2d:    0x%08lx 0x%08lx %5lu %s   %s     %s\n",
               entry, vpn, ppn, asid,
               sz, valid ? "V" : "-",
               (urb <= entry) ? "W" : "-");
    }

    back_to_cached();
    local_irq_restore(flags);

    return 0;
}

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

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

static int __init tlb_debugfs_init(void)
{
    struct dentry *itlb, *utlb;

    itlb = debugfs_create_file("itlb", S_IRUSR, arch_debugfs_dir,
                   (unsigned int *)TLB_TYPE_ITLB,
                   &tlb_debugfs_fops);
    if (unlikely(!itlb))
        return -ENOMEM;

    utlb = debugfs_create_file("utlb", S_IRUSR, arch_debugfs_dir,
                   (unsigned int *)TLB_TYPE_UTLB,
                   &tlb_debugfs_fops);
    if (unlikely(!utlb)) {
        debugfs_remove(itlb);
        return -ENOMEM;
    }

    return 0;
}
module_init(tlb_debugfs_init);

MODULE_LICENSE("GPL v2");