/*
 * QEMU SPARC iommu emulation
 *
 * Copyright (c) 2003-2005 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"

/* debug iommu */
//#define DEBUG_IOMMU

#ifdef DEBUG_IOMMU
#define DPRINTF(fmt, args...) \
do { printf("IOMMU: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif

#define IOMMU_NREGS (3*4096/4)
#define IOMMU_CTRL          (0x0000 >> 2)
#define IOMMU_CTRL_IMPL     0xf0000000 /* Implementation */
#define IOMMU_CTRL_VERS     0x0f000000 /* Version */
#define IOMMU_VERSION       0x04000000
#define IOMMU_CTRL_RNGE     0x0000001c /* Mapping RANGE */
#define IOMMU_RNGE_16MB     0x00000000 /* 0xff000000 -> 0xffffffff */
#define IOMMU_RNGE_32MB     0x00000004 /* 0xfe000000 -> 0xffffffff */
#define IOMMU_RNGE_64MB     0x00000008 /* 0xfc000000 -> 0xffffffff */
#define IOMMU_RNGE_128MB    0x0000000c /* 0xf8000000 -> 0xffffffff */
#define IOMMU_RNGE_256MB    0x00000010 /* 0xf0000000 -> 0xffffffff */
#define IOMMU_RNGE_512MB    0x00000014 /* 0xe0000000 -> 0xffffffff */
#define IOMMU_RNGE_1GB      0x00000018 /* 0xc0000000 -> 0xffffffff */
#define IOMMU_RNGE_2GB      0x0000001c /* 0x80000000 -> 0xffffffff */
#define IOMMU_CTRL_ENAB     0x00000001 /* IOMMU Enable */
#define IOMMU_CTRL_MASK     0x0000001d

#define IOMMU_BASE          (0x0004 >> 2)
#define IOMMU_BASE_MASK     0x07fffc00

#define IOMMU_TLBFLUSH      (0x0014 >> 2)
#define IOMMU_TLBFLUSH_MASK 0xffffffff

#define IOMMU_PGFLUSH       (0x0018 >> 2)
#define IOMMU_PGFLUSH_MASK  0xffffffff

#define IOMMU_AFSR          (0x1000 >> 2)
#define IOMMU_AFSR_ERR      0x80000000 /* LE, TO, or BE asserted */
#define IOMMU_AFSR_LE       0x40000000 /* SBUS reports error after transaction */
#define IOMMU_AFSR_TO       0x20000000 /* Write access took more than 12.8 us. */
#define IOMMU_AFSR_BE       0x10000000 /* Write access received error acknowledge */
#define IOMMU_AFSR_SIZE     0x0e000000 /* Size of transaction causing error */
#define IOMMU_AFSR_S        0x01000000 /* Sparc was in supervisor mode */
#define IOMMU_AFSR_RESV     0x00f00000 /* Reserved, forced to 0x8 by hardware */
#define IOMMU_AFSR_ME       0x00080000 /* Multiple errors occurred */
#define IOMMU_AFSR_RD       0x00040000 /* A read operation was in progress */
#define IOMMU_AFSR_FAV      0x00020000 /* IOMMU afar has valid contents */

#define IOMMU_AFAR          (0x1004 >> 2)

#define IOMMU_SBCFG0        (0x1010 >> 2) /* SBUS configration per-slot */
#define IOMMU_SBCFG1        (0x1014 >> 2) /* SBUS configration per-slot */
#define IOMMU_SBCFG2        (0x1018 >> 2) /* SBUS configration per-slot */
#define IOMMU_SBCFG3        (0x101c >> 2) /* SBUS configration per-slot */
#define IOMMU_SBCFG_SAB30   0x00010000 /* Phys-address bit 30 when bypass enabled */
#define IOMMU_SBCFG_BA16    0x00000004 /* Slave supports 16 byte bursts */
#define IOMMU_SBCFG_BA8     0x00000002 /* Slave supports 8 byte bursts */
#define IOMMU_SBCFG_BYPASS  0x00000001 /* Bypass IOMMU, treat all addresses
                                          produced by this device as pure
                                          physical. */
#define IOMMU_SBCFG_MASK    0x00010003

#define IOMMU_ARBEN         (0x2000 >> 2) /* SBUS arbitration enable */
#define IOMMU_ARBEN_MASK    0x001f0000
#define IOMMU_MID           0x00000008

/* The format of an iopte in the page tables */
#define IOPTE_PAGE          0x07ffff00 /* Physical page number (PA[30:12]) */
#define IOPTE_CACHE         0x00000080 /* Cached (in vme IOCACHE or Viking/MXCC) */
#define IOPTE_WRITE         0x00000004 /* Writeable */
#define IOPTE_VALID         0x00000002 /* IOPTE is valid */
#define IOPTE_WAZ           0x00000001 /* Write as zeros */

#define PAGE_SHIFT      12
#define PAGE_SIZE       (1 << PAGE_SHIFT)
#define PAGE_MASK       (PAGE_SIZE - 1)

typedef struct IOMMUState {
    target_phys_addr_t addr;
    uint32_t regs[IOMMU_NREGS];
    target_phys_addr_t iostart;
} IOMMUState;

static uint32_t iommu_mem_readw(void *opaque, target_phys_addr_t addr)
{
    IOMMUState *s = opaque;
    target_phys_addr_t saddr;

    saddr = (addr - s->addr) >> 2;
    switch (saddr) {
    default:
        DPRINTF("read reg[%d] = %x\n", (int)saddr, s->regs[saddr]);
        return s->regs[saddr];
        break;
    }
    return 0;
}

static void iommu_mem_writew(void *opaque, target_phys_addr_t addr, uint32_t val)
{
    IOMMUState *s = opaque;
    target_phys_addr_t saddr;

    saddr = (addr - s->addr) >> 2;
    DPRINTF("write reg[%d] = %x\n", (int)saddr, val);
    switch (saddr) {
    case IOMMU_CTRL:
        switch (val & IOMMU_CTRL_RNGE) {
        case IOMMU_RNGE_16MB:
            s->iostart = 0xffffffffff000000ULL;
            break;
        case IOMMU_RNGE_32MB:
            s->iostart = 0xfffffffffe000000ULL;
            break;
        case IOMMU_RNGE_64MB:
            s->iostart = 0xfffffffffc000000ULL;
            break;
        case IOMMU_RNGE_128MB:
            s->iostart = 0xfffffffff8000000ULL;
            break;
        case IOMMU_RNGE_256MB:
            s->iostart = 0xfffffffff0000000ULL;
            break;
        case IOMMU_RNGE_512MB:
            s->iostart = 0xffffffffe0000000ULL;
            break;
        case IOMMU_RNGE_1GB:
            s->iostart = 0xffffffffc0000000ULL;
            break;
        default:
        case IOMMU_RNGE_2GB:
            s->iostart = 0xffffffff80000000ULL;
            break;
        }
        DPRINTF("iostart = " TARGET_FMT_plx "\n", s->iostart);
        s->regs[saddr] = ((val & IOMMU_CTRL_MASK) | IOMMU_VERSION);
        break;
    case IOMMU_BASE:
        s->regs[saddr] = val & IOMMU_BASE_MASK;
        break;
    case IOMMU_TLBFLUSH:
        DPRINTF("tlb flush %x\n", val);
        s->regs[saddr] = val & IOMMU_TLBFLUSH_MASK;
        break;
    case IOMMU_PGFLUSH:
        DPRINTF("page flush %x\n", val);
        s->regs[saddr] = val & IOMMU_PGFLUSH_MASK;
        break;
    case IOMMU_SBCFG0:
    case IOMMU_SBCFG1:
    case IOMMU_SBCFG2:
    case IOMMU_SBCFG3:
        s->regs[saddr] = val & IOMMU_SBCFG_MASK;
        break;
    case IOMMU_ARBEN:
        // XXX implement SBus probing: fault when reading unmapped
        // addresses, fault cause and address stored to MMU/IOMMU
        s->regs[saddr] = (val & IOMMU_ARBEN_MASK) | IOMMU_MID;
        break;
    default:
        s->regs[saddr] = val;
        break;
    }
}

static CPUReadMemoryFunc *iommu_mem_read[3] = {
    iommu_mem_readw,
    iommu_mem_readw,
    iommu_mem_readw,
};

static CPUWriteMemoryFunc *iommu_mem_write[3] = {
    iommu_mem_writew,
    iommu_mem_writew,
    iommu_mem_writew,
};

static uint32_t iommu_page_get_flags(IOMMUState *s, target_phys_addr_t addr)
{
    uint32_t ret;
    target_phys_addr_t iopte;
#ifdef DEBUG_IOMMU
    target_phys_addr_t pa = addr;
#endif

    iopte = s->regs[IOMMU_BASE] << 4;
    addr &= ~s->iostart;
    iopte += (addr >> (PAGE_SHIFT - 2)) & ~3;
    cpu_physical_memory_read(iopte, (uint8_t *)&ret, 4);
    tswap32s(&ret);
    DPRINTF("get flags addr " TARGET_FMT_plx " => pte " TARGET_FMT_plx
            ", *pte = %x\n", pa, iopte, ret);

    return ret;
}

static target_phys_addr_t iommu_translate_pa(IOMMUState *s,
                                             target_phys_addr_t addr,
                                             uint32_t pte)
{
    uint32_t tmppte;
    target_phys_addr_t pa;

    tmppte = pte;
    pa = ((pte & IOPTE_PAGE) << 4) + (addr & PAGE_MASK);
    DPRINTF("xlate dva " TARGET_FMT_plx " => pa " TARGET_FMT_plx
            " (iopte = %x)\n", addr, pa, tmppte);

    return pa;
}

static void iommu_bad_addr(IOMMUState *s, target_phys_addr_t addr, int is_write)
{
    DPRINTF("bad addr " TARGET_FMT_plx "\n", addr);
    s->regs[IOMMU_AFSR] = IOMMU_AFSR_ERR | IOMMU_AFSR_LE | (8 << 20) |
        IOMMU_AFSR_FAV;
    if (!is_write)
        s->regs[IOMMU_AFSR] |= IOMMU_AFSR_RD;
    s->regs[IOMMU_AFAR] = addr;
}

void sparc_iommu_memory_rw(void *opaque, target_phys_addr_t addr,
                           uint8_t *buf, int len, int is_write)
{
    int l;
    uint32_t flags;
    target_phys_addr_t page, phys_addr;

    while (len > 0) {
        page = addr & TARGET_PAGE_MASK;
        l = (page + TARGET_PAGE_SIZE) - addr;
        if (l > len)
            l = len;
        flags = iommu_page_get_flags(opaque, page);
        if (!(flags & IOPTE_VALID)) {
            iommu_bad_addr(opaque, page, is_write);
            return;
        }
        phys_addr = iommu_translate_pa(opaque, addr, flags);
        if (is_write) {
            if (!(flags & IOPTE_WRITE)) {
                iommu_bad_addr(opaque, page, is_write);
                return;
            }
            cpu_physical_memory_write(phys_addr, buf, len);
        } else {
            cpu_physical_memory_read(phys_addr, buf, len);
        }
        len -= l;
        buf += l;
        addr += l;
    }
}

static void iommu_save(QEMUFile *f, void *opaque)
{
    IOMMUState *s = opaque;
    int i;

    for (i = 0; i < IOMMU_NREGS; i++)
        qemu_put_be32s(f, &s->regs[i]);
    qemu_put_be64s(f, &s->iostart);
}

static int iommu_load(QEMUFile *f, void *opaque, int version_id)
{
    IOMMUState *s = opaque;
    int i;

    if (version_id != 2)
        return -EINVAL;

    for (i = 0; i < IOMMU_NREGS; i++)
        qemu_get_be32s(f, &s->regs[i]);
    qemu_get_be64s(f, &s->iostart);

    return 0;
}

static void iommu_reset(void *opaque)
{
    IOMMUState *s = opaque;

    memset(s->regs, 0, IOMMU_NREGS * 4);
    s->iostart = 0;
    s->regs[IOMMU_CTRL] = IOMMU_VERSION;
}

void *iommu_init(target_phys_addr_t addr)
{
    IOMMUState *s;
    int iommu_io_memory;

    s = qemu_mallocz(sizeof(IOMMUState));
    if (!s)
        return NULL;

    s->addr = addr;

    iommu_io_memory = cpu_register_io_memory(0, iommu_mem_read, iommu_mem_write, s);
    cpu_register_physical_memory(addr, IOMMU_NREGS * 4, iommu_io_memory);

    register_savevm("iommu", addr, 2, iommu_save, iommu_load, s);
    qemu_register_reset(iommu_reset, s);
    return s;
}