/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (C) 2010 Nathan Whitehorn
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/msgbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/vmmeter.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/vm_pageout.h>
#include <vm/uma.h>

#include <powerpc/aim/mmu_oea64.h>

#include "ps3-hvcall.h"

#define VSID_HASH_MASK          0x0000007fffffffffUL
#define PTESYNC()               __asm __volatile("ptesync")

extern int ps3fb_remap(void);

static uint64_t mps3_vas_id;

/*
 * Kernel MMU interface
 */

static void     mps3_install(void);
static void     mps3_bootstrap(vm_offset_t kernelstart,
                    vm_offset_t kernelend);
static void     mps3_cpu_bootstrap(int ap);
static int64_t  mps3_pte_synch(struct pvo_entry *);
static int64_t  mps3_pte_clear(struct pvo_entry *, uint64_t ptebit);
static int64_t  mps3_pte_unset(struct pvo_entry *);
static int64_t  mps3_pte_insert(struct pvo_entry *);

static struct pmap_funcs mps3_methods = {
        .install = mps3_install,
        .bootstrap = mps3_bootstrap,
        .cpu_bootstrap = mps3_cpu_bootstrap,
};

static struct moea64_funcs mps3_funcs = {
        .pte_synch = mps3_pte_synch,
        .pte_clear = mps3_pte_clear,
        .pte_unset = mps3_pte_unset,
        .pte_insert = mps3_pte_insert,
};

MMU_DEF_INHERIT(ps3_mmu, "mmu_ps3", mps3_methods, oea64_mmu);

static struct mtx mps3_table_lock;

static void
mps3_install(void)
{
        moea64_ops = &mps3_funcs;
        moea64_install();
}

static void
mps3_bootstrap(vm_offset_t kernelstart, vm_offset_t kernelend)
{
        uint64_t final_pteg_count;

        mtx_init(&mps3_table_lock, "page table", NULL, MTX_DEF);

        moea64_early_bootstrap(kernelstart, kernelend);

        /* In case we had a page table already */
        lv1_destruct_virtual_address_space(0);

        /* Allocate new hardware page table */
        lv1_construct_virtual_address_space(
            20 /* log_2(moea64_pteg_count) */, 2 /* n page sizes */,
            (24UL << 56) | (16UL << 48) /* page sizes 16 MB + 64 KB */,
            &mps3_vas_id, &final_pteg_count
        );

        lv1_select_virtual_address_space(mps3_vas_id);

        moea64_pteg_count = final_pteg_count / sizeof(struct lpteg);

        moea64_mid_bootstrap(kernelstart, kernelend);
        moea64_late_bootstrap(kernelstart, kernelend);
}

static void
mps3_cpu_bootstrap(int ap)
{
        struct slb *slb = PCPU_GET(aim.slb);
        register_t seg0;
        int i;

        mtmsr(mfmsr() & ~PSL_DR & ~PSL_IR);

        /*
         * Select the page table we configured above and set up the FB mapping
         * so we can have a console.
         */
        lv1_select_virtual_address_space(mps3_vas_id);

        if (!ap)
                ps3fb_remap();

        /*
         * Install kernel SLB entries
         */

        __asm __volatile ("slbia");
        __asm __volatile ("slbmfee %0,%1; slbie %0;" : "=r"(seg0) : "r"(0));
        for (i = 0; i < 64; i++) {
                if (!(slb[i].slbe & SLBE_VALID))
                        continue;

                __asm __volatile ("slbmte %0, %1" ::
                    "r"(slb[i].slbv), "r"(slb[i].slbe));
        }
}

static int64_t
mps3_pte_synch_locked(struct pvo_entry *pvo)
{
        uint64_t halfbucket[4], rcbits;

        PTESYNC();
        lv1_read_htab_entries(mps3_vas_id, pvo->pvo_pte.slot & ~0x3UL,
            &halfbucket[0], &halfbucket[1], &halfbucket[2], &halfbucket[3],
            &rcbits);

        /* Check if present in page table */
        if ((halfbucket[pvo->pvo_pte.slot & 0x3] & LPTE_AVPN_MASK) !=
            ((pvo->pvo_vpn >> (ADDR_API_SHFT64 - ADDR_PIDX_SHFT)) &
            LPTE_AVPN_MASK))
                return (-1);
        if (!(halfbucket[pvo->pvo_pte.slot & 0x3] & LPTE_VALID))
                return (-1);

        /*
         * rcbits contains the low 12 bits of each PTE's 2nd part,
         * spaced at 16-bit intervals
         */

        return ((rcbits >> ((3 - (pvo->pvo_pte.slot & 0x3))*16)) &
            (LPTE_CHG | LPTE_REF));
}

static int64_t
mps3_pte_synch(struct pvo_entry *pvo)
{
        int64_t retval;

        mtx_lock(&mps3_table_lock);
        retval = mps3_pte_synch_locked(pvo);
        mtx_unlock(&mps3_table_lock);

        return (retval);
}

static int64_t
mps3_pte_clear(struct pvo_entry *pvo, uint64_t ptebit)
{
        int64_t refchg;
        struct lpte pte;

        mtx_lock(&mps3_table_lock);

        refchg = mps3_pte_synch_locked(pvo);
        if (refchg < 0) {
                mtx_unlock(&mps3_table_lock);
                return (refchg);
        }

        moea64_pte_from_pvo(pvo, &pte);

        pte.pte_lo |= refchg;
        pte.pte_lo &= ~ptebit;
        /* XXX: race on RC bits between write and sync. Anything to do? */
        lv1_write_htab_entry(mps3_vas_id, pvo->pvo_pte.slot, pte.pte_hi,
            pte.pte_lo);
        mtx_unlock(&mps3_table_lock);

        return (refchg);
}

static int64_t
mps3_pte_unset(struct pvo_entry *pvo)
{
        int64_t refchg;

        mtx_lock(&mps3_table_lock);
        refchg = mps3_pte_synch_locked(pvo);
        if (refchg < 0) {
                STAT_MOEA64(moea64_pte_overflow--);
                mtx_unlock(&mps3_table_lock);
                return (-1);
        }
        /* XXX: race on RC bits between unset and sync. Anything to do? */
        lv1_write_htab_entry(mps3_vas_id, pvo->pvo_pte.slot, 0, 0);
        mtx_unlock(&mps3_table_lock);
        STAT_MOEA64(moea64_pte_valid--);

        return (refchg & (LPTE_REF | LPTE_CHG));
}

static int64_t
mps3_pte_insert(struct pvo_entry *pvo)
{
        int result;
        struct lpte pte, evicted;
        uint64_t index;

        if (pvo->pvo_vaddr & PVO_HID) {
                /* Hypercall needs primary PTEG */
                pvo->pvo_vaddr &= ~PVO_HID;
                pvo->pvo_pte.slot ^= (moea64_pteg_mask << 3);
        }

        pvo->pvo_pte.slot &= ~7UL;
        moea64_pte_from_pvo(pvo, &pte);
        evicted.pte_hi = 0;
        PTESYNC();
        mtx_lock(&mps3_table_lock);
        result = lv1_insert_htab_entry(mps3_vas_id, pvo->pvo_pte.slot,
            pte.pte_hi, pte.pte_lo, LPTE_LOCKED | LPTE_WIRED, 0,
            &index, &evicted.pte_hi, &evicted.pte_lo);
        mtx_unlock(&mps3_table_lock);

        if (result != 0) {
                /* No freeable slots in either PTEG? We're hosed. */
                panic("mps3_pte_insert: overflow (%d)", result);
                return (-1);
        }

        /*
         * See where we ended up.
         */
        if ((index & ~7UL) != pvo->pvo_pte.slot)
                pvo->pvo_vaddr |= PVO_HID;
        pvo->pvo_pte.slot = index;

        STAT_MOEA64(moea64_pte_valid++);

        if (evicted.pte_hi) {
                KASSERT((evicted.pte_hi & (LPTE_WIRED | LPTE_LOCKED)) == 0,
                    ("Evicted a wired PTE"));
                STAT_MOEA64(moea64_pte_valid--);
                STAT_MOEA64(moea64_pte_overflow++);
        }

        return (0);
}