/*
 * Copyright (C) 2014-2016 Broadcom Corporation
 * Copyright (c) 2017 Red Hat, Inc.
 * Written by Prem Mallappa, Eric Auger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Author: Prem Mallappa <pmallapp@broadcom.com>
 *
 */

#include "qemu/osdep.h"
#include "sysemu/sysemu.h"
#include "exec/address-spaces.h"
#include "trace.h"
#include "exec/target_page.h"
#include "qom/cpu.h"
#include "hw/qdev-properties.h"
#include "qapi/error.h"

#include "qemu/error-report.h"
#include "hw/arm/smmu-common.h"
#include "smmu-internal.h"

/* VMSAv8-64 Translation */

/**
 * get_pte - Get the content of a page table entry located at
 * @base_addr[@index]
 */
static int get_pte(dma_addr_t baseaddr, uint32_t index, uint64_t *pte,
                   SMMUPTWEventInfo *info)
{
    int ret;
    dma_addr_t addr = baseaddr + index * sizeof(*pte);

    /* TODO: guarantee 64-bit single-copy atomicity */
    ret = dma_memory_read(&address_space_memory, addr,
                          (uint8_t *)pte, sizeof(*pte));

    if (ret != MEMTX_OK) {
        info->type = SMMU_PTW_ERR_WALK_EABT;
        info->addr = addr;
        return -EINVAL;
    }
    trace_smmu_get_pte(baseaddr, index, addr, *pte);
    return 0;
}

/* VMSAv8-64 Translation Table Format Descriptor Decoding */

/**
 * get_page_pte_address - returns the L3 descriptor output address,
 * ie. the page frame
 * ARM ARM spec: Figure D4-17 VMSAv8-64 level 3 descriptor format
 */
static inline hwaddr get_page_pte_address(uint64_t pte, int granule_sz)
{
    return PTE_ADDRESS(pte, granule_sz);
}

/**
 * get_table_pte_address - return table descriptor output address,
 * ie. address of next level table
 * ARM ARM Figure D4-16 VMSAv8-64 level0, level1, and level 2 descriptor formats
 */
static inline hwaddr get_table_pte_address(uint64_t pte, int granule_sz)
{
    return PTE_ADDRESS(pte, granule_sz);
}

/**
 * get_block_pte_address - return block descriptor output address and block size
 * ARM ARM Figure D4-16 VMSAv8-64 level0, level1, and level 2 descriptor formats
 */
static inline hwaddr get_block_pte_address(uint64_t pte, int level,
                                           int granule_sz, uint64_t *bsz)
{
    int n = level_shift(level, granule_sz);

    *bsz = 1ULL << n;
    return PTE_ADDRESS(pte, n);
}

SMMUTransTableInfo *select_tt(SMMUTransCfg *cfg, dma_addr_t iova)
{
    bool tbi = extract64(iova, 55, 1) ? TBI1(cfg->tbi) : TBI0(cfg->tbi);
    uint8_t tbi_byte = tbi * 8;

    if (cfg->tt[0].tsz &&
        !extract64(iova, 64 - cfg->tt[0].tsz, cfg->tt[0].tsz - tbi_byte)) {
        /* there is a ttbr0 region and we are in it (high bits all zero) */
        return &cfg->tt[0];
    } else if (cfg->tt[1].tsz &&
           !extract64(iova, 64 - cfg->tt[1].tsz, cfg->tt[1].tsz - tbi_byte)) {
        /* there is a ttbr1 region and we are in it (high bits all one) */
        return &cfg->tt[1];
    } else if (!cfg->tt[0].tsz) {
        /* ttbr0 region is "everything not in the ttbr1 region" */
        return &cfg->tt[0];
    } else if (!cfg->tt[1].tsz) {
        /* ttbr1 region is "everything not in the ttbr0 region" */
        return &cfg->tt[1];
    }
    /* in the gap between the two regions, this is a Translation fault */
    return NULL;
}

/**
 * smmu_ptw_64 - VMSAv8-64 Walk of the page tables for a given IOVA
 * @cfg: translation config
 * @iova: iova to translate
 * @perm: access type
 * @tlbe: IOMMUTLBEntry (out)
 * @info: handle to an error info
 *
 * Return 0 on success, < 0 on error. In case of error, @info is filled
 * and tlbe->perm is set to IOMMU_NONE.
 * Upon success, @tlbe is filled with translated_addr and entry
 * permission rights.
 */
static int smmu_ptw_64(SMMUTransCfg *cfg,
                       dma_addr_t iova, IOMMUAccessFlags perm,
                       IOMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
{
    dma_addr_t baseaddr, indexmask;
    int stage = cfg->stage;
    SMMUTransTableInfo *tt = select_tt(cfg, iova);
    uint8_t level, granule_sz, inputsize, stride;

    if (!tt || tt->disabled) {
        info->type = SMMU_PTW_ERR_TRANSLATION;
        goto error;
    }

    granule_sz = tt->granule_sz;
    stride = granule_sz - 3;
    inputsize = 64 - tt->tsz;
    level = 4 - (inputsize - 4) / stride;
    indexmask = (1ULL << (inputsize - (stride * (4 - level)))) - 1;
    baseaddr = extract64(tt->ttb, 0, 48);
    baseaddr &= ~indexmask;

    tlbe->iova = iova;
    tlbe->addr_mask = (1 << granule_sz) - 1;

    while (level <= 3) {
        uint64_t subpage_size = 1ULL << level_shift(level, granule_sz);
        uint64_t mask = subpage_size - 1;
        uint32_t offset = iova_level_offset(iova, inputsize, level, granule_sz);
        uint64_t pte;
        dma_addr_t pte_addr = baseaddr + offset * sizeof(pte);
        uint8_t ap;

        if (get_pte(baseaddr, offset, &pte, info)) {
                goto error;
        }
        trace_smmu_ptw_level(level, iova, subpage_size,
                             baseaddr, offset, pte);

        if (is_invalid_pte(pte) || is_reserved_pte(pte, level)) {
            trace_smmu_ptw_invalid_pte(stage, level, baseaddr,
                                       pte_addr, offset, pte);
            info->type = SMMU_PTW_ERR_TRANSLATION;
            goto error;
        }

        if (is_page_pte(pte, level)) {
            uint64_t gpa = get_page_pte_address(pte, granule_sz);

            ap = PTE_AP(pte);
            if (is_permission_fault(ap, perm)) {
                info->type = SMMU_PTW_ERR_PERMISSION;
                goto error;
            }

            tlbe->translated_addr = gpa + (iova & mask);
            tlbe->perm = PTE_AP_TO_PERM(ap);
            trace_smmu_ptw_page_pte(stage, level, iova,
                                    baseaddr, pte_addr, pte, gpa);
            return 0;
        }
        if (is_block_pte(pte, level)) {
            uint64_t block_size;
            hwaddr gpa = get_block_pte_address(pte, level, granule_sz,
                                               &block_size);

            ap = PTE_AP(pte);
            if (is_permission_fault(ap, perm)) {
                info->type = SMMU_PTW_ERR_PERMISSION;
                goto error;
            }

            trace_smmu_ptw_block_pte(stage, level, baseaddr,
                                     pte_addr, pte, iova, gpa,
                                     block_size >> 20);

            tlbe->translated_addr = gpa + (iova & mask);
            tlbe->perm = PTE_AP_TO_PERM(ap);
            return 0;
        }

        /* table pte */
        ap = PTE_APTABLE(pte);

        if (is_permission_fault(ap, perm)) {
            info->type = SMMU_PTW_ERR_PERMISSION;
            goto error;
        }
        baseaddr = get_table_pte_address(pte, granule_sz);
        level++;
    }

    info->type = SMMU_PTW_ERR_TRANSLATION;

error:
    tlbe->perm = IOMMU_NONE;
    return -EINVAL;
}

/**
 * smmu_ptw - Walk the page tables for an IOVA, according to @cfg
 *
 * @cfg: translation configuration
 * @iova: iova to translate
 * @perm: tentative access type
 * @tlbe: returned entry
 * @info: ptw event handle
 *
 * return 0 on success
 */
inline int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova, IOMMUAccessFlags perm,
             IOMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
{
    if (!cfg->aa64) {
        /*
         * This code path is not entered as we check this while decoding
         * the configuration data in the derived SMMU model.
         */
        g_assert_not_reached();
    }

    return smmu_ptw_64(cfg, iova, perm, tlbe, info);
}

/**
 * The bus number is used for lookup when SID based invalidation occurs.
 * In that case we lazily populate the SMMUPciBus array from the bus hash
 * table. At the time the SMMUPciBus is created (smmu_find_add_as), the bus
 * numbers may not be always initialized yet.
 */
SMMUPciBus *smmu_find_smmu_pcibus(SMMUState *s, uint8_t bus_num)
{
    SMMUPciBus *smmu_pci_bus = s->smmu_pcibus_by_bus_num[bus_num];

    if (!smmu_pci_bus) {
        GHashTableIter iter;

        g_hash_table_iter_init(&iter, s->smmu_pcibus_by_busptr);
        while (g_hash_table_iter_next(&iter, NULL, (void **)&smmu_pci_bus)) {
            if (pci_bus_num(smmu_pci_bus->bus) == bus_num) {
                s->smmu_pcibus_by_bus_num[bus_num] = smmu_pci_bus;
                return smmu_pci_bus;
            }
        }
    }
    return smmu_pci_bus;
}

static AddressSpace *smmu_find_add_as(PCIBus *bus, void *opaque, int devfn)
{
    SMMUState *s = opaque;
    SMMUPciBus *sbus = g_hash_table_lookup(s->smmu_pcibus_by_busptr, bus);
    SMMUDevice *sdev;

    if (!sbus) {
        sbus = g_malloc0(sizeof(SMMUPciBus) +
                         sizeof(SMMUDevice *) * SMMU_PCI_DEVFN_MAX);
        sbus->bus = bus;
        g_hash_table_insert(s->smmu_pcibus_by_busptr, bus, sbus);
    }

    sdev = sbus->pbdev[devfn];
    if (!sdev) {
        char *name = g_strdup_printf("%s-%d-%d",
                                     s->mrtypename,
                                     pci_bus_num(bus), devfn);
        sdev = sbus->pbdev[devfn] = g_new0(SMMUDevice, 1);

        sdev->smmu = s;
        sdev->bus = bus;
        sdev->devfn = devfn;

        memory_region_init_iommu(&sdev->iommu, sizeof(sdev->iommu),
                                 s->mrtypename,
                                 OBJECT(s), name, 1ULL << SMMU_MAX_VA_BITS);
        address_space_init(&sdev->as,
                           MEMORY_REGION(&sdev->iommu), name);
        trace_smmu_add_mr(name);
        g_free(name);
    }

    return &sdev->as;
}

static void smmu_base_realize(DeviceState *dev, Error **errp)
{
    SMMUState *s = ARM_SMMU(dev);
    SMMUBaseClass *sbc = ARM_SMMU_GET_CLASS(dev);
    Error *local_err = NULL;

    sbc->parent_realize(dev, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        return;
    }

    s->smmu_pcibus_by_busptr = g_hash_table_new(NULL, NULL);

    if (s->primary_bus) {
        pci_setup_iommu(s->primary_bus, smmu_find_add_as, s);
    } else {
        error_setg(errp, "SMMU is not attached to any PCI bus!");
    }
}

static void smmu_base_reset(DeviceState *dev)
{
    /* will be filled later on */
}

static Property smmu_dev_properties[] = {
    DEFINE_PROP_UINT8("bus_num", SMMUState, bus_num, 0),
    DEFINE_PROP_LINK("primary-bus", SMMUState, primary_bus, "PCI", PCIBus *),
    DEFINE_PROP_END_OF_LIST(),
};

static void smmu_base_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    SMMUBaseClass *sbc = ARM_SMMU_CLASS(klass);

    dc->props = smmu_dev_properties;
    device_class_set_parent_realize(dc, smmu_base_realize,
                                    &sbc->parent_realize);
    dc->reset = smmu_base_reset;
}

static const TypeInfo smmu_base_info = {
    .name          = TYPE_ARM_SMMU,
    .parent        = TYPE_SYS_BUS_DEVICE,
    .instance_size = sizeof(SMMUState),
    .class_data    = NULL,
    .class_size    = sizeof(SMMUBaseClass),
    .class_init    = smmu_base_class_init,
    .abstract      = true,
};

static void smmu_base_register_types(void)
{
    type_register_static(&smmu_base_info);
}

type_init(smmu_base_register_types)