/*
 * PowerPC hash table management proc entry.  Will show information
 * about the current hash table and will allow changes to it.
 *
 * Written by Cort Dougan (cort@cs.nmt.edu)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/threads.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/mmu.h>
#include <asm/residual.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/cputable.h>
#include <asm/system.h>
#include <asm/reg.h>

static int ppc_htab_show(struct seq_file *m, void *v);
static ssize_t ppc_htab_write(struct file * file, const char __user * buffer,
                              size_t count, loff_t *ppos);
extern PTE *Hash, *Hash_end;
extern unsigned long Hash_size, Hash_mask;
extern unsigned long _SDR1;
extern unsigned long htab_reloads;
extern unsigned long htab_preloads;
extern unsigned long htab_evicts;
extern unsigned long pte_misses;
extern unsigned long pte_errors;
extern unsigned int primary_pteg_full;
extern unsigned int htab_hash_searches;

static int ppc_htab_open(struct inode *inode, struct file *file)
{
        return single_open(file, ppc_htab_show, NULL);
}

const struct file_operations ppc_htab_operations = {
        .open           = ppc_htab_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .write          = ppc_htab_write,
        .release        = single_release,
};

static char *pmc1_lookup(unsigned long mmcr0)
{
        switch ( mmcr0 & (0x7f<<7) )
        {
        case 0x0:
                return "none";
        case MMCR0_PMC1_CYCLES:
                return "cycles";
        case MMCR0_PMC1_ICACHEMISS:
                return "ic miss";
        case MMCR0_PMC1_DTLB:
                return "dtlb miss";
        default:
                return "unknown";
        }
}

static char *pmc2_lookup(unsigned long mmcr0)
{
        switch ( mmcr0 & 0x3f )
        {
        case 0x0:
                return "none";
        case MMCR0_PMC2_CYCLES:
                return "cycles";
        case MMCR0_PMC2_DCACHEMISS:
                return "dc miss";
        case MMCR0_PMC2_ITLB:
                return "itlb miss";
        case MMCR0_PMC2_LOADMISSTIME:
                return "load miss time";
        default:
                return "unknown";
        }
}

/*
 * print some useful info about the hash table.  This function
 * is _REALLY_ slow (see the nested for loops below) but nothing
 * in here should be really timing critical. -- Cort
 */
static int ppc_htab_show(struct seq_file *m, void *v)
{
        unsigned long mmcr0 = 0, pmc1 = 0, pmc2 = 0;
#if defined(CONFIG_PPC_STD_MMU)
        unsigned int kptes = 0, uptes = 0;
        PTE *ptr;
#endif /* CONFIG_PPC_STD_MMU */

        if (cpu_has_feature(CPU_FTR_604_PERF_MON)) {
                mmcr0 = mfspr(SPRN_MMCR0);
                pmc1 = mfspr(SPRN_PMC1);
                pmc2 = mfspr(SPRN_PMC2);
                seq_printf(m,
                              "604 Performance Monitoring\n"
                              "MMCR0\t\t: %08lx %s%s ",
                              mmcr0,
                              ( mmcr0>>28 & 0x2 ) ? "(user mode counted)" : "",
                              ( mmcr0>>28 & 0x4 ) ? "(kernel mode counted)" : "");
                seq_printf(m,
                              "\nPMC1\t\t: %08lx (%s)\n"
                              "PMC2\t\t: %08lx (%s)\n",
                              pmc1, pmc1_lookup(mmcr0),
                              pmc2, pmc2_lookup(mmcr0));
        }

#ifdef CONFIG_PPC_STD_MMU
        /* if we don't have a htab */
        if ( Hash_size == 0 ) {
                seq_printf(m, "No Hash Table used\n");
                return 0;
        }

        for (ptr = Hash; ptr < Hash_end; ptr++) {
                unsigned int mctx, vsid;

                if (!ptr->v)
                        continue;
                /* undo the esid skew */
                vsid = ptr->vsid;
                mctx = ((vsid - (vsid & 0xf) * 0x111) >> 4) & 0xfffff;
                if (mctx == 0)
                        kptes++;
                else
                        uptes++;
        }

        seq_printf(m,
                      "PTE Hash Table Information\n"
                      "Size\t\t: %luKb\n"
                      "Buckets\t\t: %lu\n"
                      "Address\t\t: %08lx\n"
                      "Entries\t\t: %lu\n"
                      "User ptes\t: %u\n"
                      "Kernel ptes\t: %u\n"
                      "Percent full\t: %lu%%\n"
                      , (unsigned long)(Hash_size>>10),
                      (Hash_size/(sizeof(PTE)*8)),
                      (unsigned long)Hash,
                      Hash_size/sizeof(PTE)
                      , uptes,
                      kptes,
                      ((kptes+uptes)*100) / (Hash_size/sizeof(PTE))
                );

        seq_printf(m,
                      "Reloads\t\t: %lu\n"
                      "Preloads\t: %lu\n"
                      "Searches\t: %u\n"
                      "Overflows\t: %u\n"
                      "Evicts\t\t: %lu\n",
                      htab_reloads, htab_preloads, htab_hash_searches,
                      primary_pteg_full, htab_evicts);
#endif /* CONFIG_PPC_STD_MMU */

        seq_printf(m,
                      "Non-error misses: %lu\n"
                      "Error misses\t: %lu\n",
                      pte_misses, pte_errors);
        return 0;
}

/*
 * Allow user to define performance counters and resize the hash table
 */
static ssize_t ppc_htab_write(struct file * file, const char __user * ubuffer,
                              size_t count, loff_t *ppos)
{
#ifdef CONFIG_PPC_STD_MMU
        unsigned long tmp;
        char buffer[16];

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (strncpy_from_user(buffer, ubuffer, 15))
                return -EFAULT;
        buffer[15] = 0;

        /* don't set the htab size for now */
        if ( !strncmp( buffer, "size ", 5) )
                return -EBUSY;

        if ( !strncmp( buffer, "reset", 5) )
        {
                if (cpu_has_feature(CPU_FTR_604_PERF_MON)) {
                        /* reset PMC1 and PMC2 */
                        mtspr(SPRN_PMC1, 0);
                        mtspr(SPRN_PMC2, 0);
                }
                htab_reloads = 0;
                htab_evicts = 0;
                pte_misses = 0;
                pte_errors = 0;
        }

        /* Everything below here requires the performance monitor feature. */
        if (!cpu_has_feature(CPU_FTR_604_PERF_MON))
                return count;

        /* turn off performance monitoring */
        if ( !strncmp( buffer, "off", 3) )
        {
                mtspr(SPRN_MMCR0, 0);
                mtspr(SPRN_PMC1, 0);
                mtspr(SPRN_PMC2, 0);
        }

        if ( !strncmp( buffer, "user", 4) )
        {
                /* setup mmcr0 and clear the correct pmc */
                tmp = (mfspr(SPRN_MMCR0) & ~(0x60000000)) | 0x20000000;
                mtspr(SPRN_MMCR0, tmp);
                mtspr(SPRN_PMC1, 0);
                mtspr(SPRN_PMC2, 0);
        }

        if ( !strncmp( buffer, "kernel", 6) )
        {
                /* setup mmcr0 and clear the correct pmc */
                tmp = (mfspr(SPRN_MMCR0) & ~(0x60000000)) | 0x40000000;
                mtspr(SPRN_MMCR0, tmp);
                mtspr(SPRN_PMC1, 0);
                mtspr(SPRN_PMC2, 0);
        }

        /* PMC1 values */
        if ( !strncmp( buffer, "dtlb", 4) )
        {
                /* setup mmcr0 and clear the correct pmc */
                tmp = (mfspr(SPRN_MMCR0) & ~(0x7F << 7)) | MMCR0_PMC1_DTLB;
                mtspr(SPRN_MMCR0, tmp);
                mtspr(SPRN_PMC1, 0);
        }

        if ( !strncmp( buffer, "ic miss", 7) )
        {
                /* setup mmcr0 and clear the correct pmc */
                tmp = (mfspr(SPRN_MMCR0) & ~(0x7F<<7)) | MMCR0_PMC1_ICACHEMISS;
                mtspr(SPRN_MMCR0, tmp);
                mtspr(SPRN_PMC1, 0);
        }

        /* PMC2 values */
        if ( !strncmp( buffer, "load miss time", 14) )
        {
                /* setup mmcr0 and clear the correct pmc */
               asm volatile(
                       "mfspr %0,%1\n\t"     /* get current mccr0 */
                       "rlwinm %0,%0,0,0,31-6\n\t"  /* clear bits [26-31] */
                       "ori   %0,%0,%2 \n\t" /* or in mmcr0 settings */
                       "mtspr %1,%0 \n\t"    /* set new mccr0 */
                       "mtspr %3,%4 \n\t"    /* reset the pmc */
                       : "=r" (tmp)
                       : "i" (SPRN_MMCR0),
                       "i" (MMCR0_PMC2_LOADMISSTIME),
                       "i" (SPRN_PMC2),  "r" (0) );
        }

        if ( !strncmp( buffer, "itlb", 4) )
        {
                /* setup mmcr0 and clear the correct pmc */
               asm volatile(
                       "mfspr %0,%1\n\t"     /* get current mccr0 */
                       "rlwinm %0,%0,0,0,31-6\n\t"  /* clear bits [26-31] */
                       "ori   %0,%0,%2 \n\t" /* or in mmcr0 settings */
                       "mtspr %1,%0 \n\t"    /* set new mccr0 */
                       "mtspr %3,%4 \n\t"    /* reset the pmc */
                       : "=r" (tmp)
                       : "i" (SPRN_MMCR0), "i" (MMCR0_PMC2_ITLB),
                       "i" (SPRN_PMC2),  "r" (0) );
        }

        if ( !strncmp( buffer, "dc miss", 7) )
        {
                /* setup mmcr0 and clear the correct pmc */
               asm volatile(
                       "mfspr %0,%1\n\t"     /* get current mccr0 */
                       "rlwinm %0,%0,0,0,31-6\n\t"  /* clear bits [26-31] */
                       "ori   %0,%0,%2 \n\t" /* or in mmcr0 settings */
                       "mtspr %1,%0 \n\t"    /* set new mccr0 */
                       "mtspr %3,%4 \n\t"    /* reset the pmc */
                       : "=r" (tmp)
                       : "i" (SPRN_MMCR0), "i" (MMCR0_PMC2_DCACHEMISS),
                       "i" (SPRN_PMC2),  "r" (0) );
        }

        return count;
#else /* CONFIG_PPC_STD_MMU */
        return 0;
#endif /* CONFIG_PPC_STD_MMU */
}

int proc_dol2crvec(ctl_table *table, int write, struct file *filp,
                  void __user *buffer_arg, size_t *lenp, loff_t *ppos)
{
        int vleft, first=1, len, left, val;
        char __user *buffer = (char __user *) buffer_arg;
        #define TMPBUFLEN 256
        char buf[TMPBUFLEN], *p;
        static const char *sizestrings[4] = {
                "2MB", "256KB", "512KB", "1MB"
        };
        static const char *clockstrings[8] = {
                "clock disabled", "+1 clock", "+1.5 clock", "reserved(3)",
                "+2 clock", "+2.5 clock", "+3 clock", "reserved(7)"
        };
        static const char *typestrings[4] = {
                "flow-through burst SRAM", "reserved SRAM",
                "pipelined burst SRAM", "pipelined late-write SRAM"
        };
        static const char *holdstrings[4] = {
                "0.5", "1.0", "(reserved2)", "(reserved3)"
        };

        if (!cpu_has_feature(CPU_FTR_L2CR))
                return -EFAULT;

        if ( /*!table->maxlen ||*/ (*ppos && !write)) {
                *lenp = 0;
                return 0;
        }

        vleft = table->maxlen / sizeof(int);
        left = *lenp;

        for (; left /*&& vleft--*/; first=0) {
                if (write) {
                        while (left) {
                                char c;
                                if(get_user(c, buffer))
                                        return -EFAULT;
                                if (!isspace(c))
                                        break;
                                left--;
                                buffer++;
                        }
                        if (!left)
                                break;
                        len = left;
                        if (len > TMPBUFLEN-1)
                                len = TMPBUFLEN-1;
                        if(copy_from_user(buf, buffer, len))
                                return -EFAULT;
                        buf[len] = 0;
                        p = buf;
                        if (*p < '0' || *p > '9')
                                break;
                        val = simple_strtoul(p, &p, 0);
                        len = p-buf;
                        if ((len < left) && *p && !isspace(*p))
                                break;
                        buffer += len;
                        left -= len;
                        _set_L2CR(val);
                } else {
                        p = buf;
                        if (!first)
                                *p++ = '\t';
                        val = _get_L2CR();
                        p += sprintf(p, "0x%08x: ", val);
                        p += sprintf(p, " %s", (val >> 31) & 1 ? "enabled" :
                                        "disabled");
                        p += sprintf(p, ", %sparity", (val>>30)&1 ? "" : "no ");
                        p += sprintf(p, ", %s", sizestrings[(val >> 28) & 3]);
                        p += sprintf(p, ", %s", clockstrings[(val >> 25) & 7]);
                        p += sprintf(p, ", %s", typestrings[(val >> 23) & 2]);
                        p += sprintf(p, "%s", (val>>22)&1 ? ", data only" : "");
                        p += sprintf(p, "%s", (val>>20)&1 ? ", ZZ enabled": "");
                        p += sprintf(p, ", %s", (val>>19)&1 ? "write-through" :
                                        "copy-back");
                        p += sprintf(p, "%s", (val>>18)&1 ? ", testing" : "");
                        p += sprintf(p, ", %sns hold",holdstrings[(val>>16)&3]);
                        p += sprintf(p, "%s", (val>>15)&1 ? ", DLL slow" : "");
                        p += sprintf(p, "%s", (val>>14)&1 ? ", diff clock" :"");
                        p += sprintf(p, "%s", (val>>13)&1 ? ", DLL bypass" :"");

                        p += sprintf(p,"\n");

                        len = strlen(buf);
                        if (len > left)
                                len = left;
                        if (copy_to_user(buffer, buf, len))
                                return -EFAULT;
                        left -= len;
                        buffer += len;
                        break;
                }
        }

        if (!write && !first && left) {
                if(put_user('\n', (char __user *) buffer))
                        return -EFAULT;
                left--, buffer++;
        }
        if (write) {
                char __user *s = (char __user *) buffer;
                while (left) {
                        char c;
                        if(get_user(c, s++))
                                return -EFAULT;
                        if (!isspace(c))
                                break;
                        left--;
                }
        }
        if (write && first)
                return -EINVAL;
        *lenp -= left;
        *ppos += *lenp;
        return 0;
}

#ifdef CONFIG_SYSCTL
/*
 * Register our sysctl.
 */
static ctl_table htab_ctl_table[]={
        {
                .procname       = "l2cr",
                .mode           = 0644,
                .proc_handler   = &proc_dol2crvec,
        },
        {}
};
static ctl_table htab_sysctl_root[] = {
        {
                .ctl_name       = CTL_KERN,
                .procname       = "kernel",
                .mode           = 0555,
                .child          = htab_ctl_table,
        },
        {}
};

static int __init
register_ppc_htab_sysctl(void)
{
        register_sysctl_table(htab_sysctl_root);

        return 0;
}

__initcall(register_ppc_htab_sysctl);
#endif