Archipelago » qemu

/*

 * ARM PrimeCell PL330 DMA Controller

 *

 * Copyright (c) 2009 Samsung Electronics.

 * Contributed by Kirill Batuzov <batuzovk@ispras.ru>

 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)

 * Copyright (c) 2012 PetaLogix Pty Ltd.

 *

 * 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; version 2 or later.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "hw/sysbus.h"

#include "qemu/timer.h"

#include "sysemu/dma.h"

#ifndef PL330_ERR_DEBUG

#define PL330_ERR_DEBUG 0

#endif

#define DB_PRINT_L(lvl, fmt, args...) do {\

    if (PL330_ERR_DEBUG >= lvl) {\

        fprintf(stderr, "PL330: %s:" fmt, __func__, ## args);\

    } \

} while (0);

#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)

#define PL330_PERIPH_NUM            32

#define PL330_MAX_BURST_LEN         128

#define PL330_INSN_MAXSIZE          6

#define PL330_FIFO_OK               0

#define PL330_FIFO_STALL            1

#define PL330_FIFO_ERR              (-1)

#define PL330_FAULT_UNDEF_INSTR             (1 <<  0)

#define PL330_FAULT_OPERAND_INVALID         (1 <<  1)

#define PL330_FAULT_DMAGO_ERR               (1 <<  4)

#define PL330_FAULT_EVENT_ERR               (1 <<  5)

#define PL330_FAULT_CH_PERIPH_ERR           (1 <<  6)

#define PL330_FAULT_CH_RDWR_ERR             (1 <<  7)

#define PL330_FAULT_ST_DATA_UNAVAILABLE     (1 << 12)

#define PL330_FAULT_FIFOEMPTY_ERR           (1 << 13)

#define PL330_FAULT_INSTR_FETCH_ERR         (1 << 16)

#define PL330_FAULT_DATA_WRITE_ERR          (1 << 17)

#define PL330_FAULT_DATA_READ_ERR           (1 << 18)

#define PL330_FAULT_DBG_INSTR               (1 << 30)

#define PL330_FAULT_LOCKUP_ERR              (1 << 31)

#define PL330_UNTAGGED              0xff

#define PL330_SINGLE                0x0

#define PL330_BURST                 0x1

#define PL330_WATCHDOG_LIMIT        1024

/* IOMEM mapped registers */

#define PL330_REG_DSR               0x000

#define PL330_REG_DPC               0x004

#define PL330_REG_INTEN             0x020

#define PL330_REG_INT_EVENT_RIS     0x024

#define PL330_REG_INTMIS            0x028

#define PL330_REG_INTCLR            0x02C

#define PL330_REG_FSRD              0x030

#define PL330_REG_FSRC              0x034

#define PL330_REG_FTRD              0x038

#define PL330_REG_FTR_BASE          0x040

#define PL330_REG_CSR_BASE          0x100

#define PL330_REG_CPC_BASE          0x104

#define PL330_REG_CHANCTRL          0x400

#define PL330_REG_DBGSTATUS         0xD00

#define PL330_REG_DBGCMD            0xD04

#define PL330_REG_DBGINST0          0xD08

#define PL330_REG_DBGINST1          0xD0C

#define PL330_REG_CR0_BASE          0xE00

#define PL330_REG_PERIPH_ID         0xFE0

#define PL330_IOMEM_SIZE    0x1000

#define CFG_BOOT_ADDR 2

#define CFG_INS 3

#define CFG_PNS 4

#define CFG_CRD 5

static const uint32_t pl330_id[] = {

    0x30, 0x13, 0x24, 0x00, 0x0D, 0xF0, 0x05, 0xB1

};

/* DMA channel states as they are described in PL330 Technical Reference Manual

 * Most of them will not be used in emulation.

 */

typedef enum  {

    pl330_chan_stopped = 0,

    pl330_chan_executing = 1,

    pl330_chan_cache_miss = 2,

    pl330_chan_updating_pc = 3,

    pl330_chan_waiting_event = 4,

    pl330_chan_at_barrier = 5,

    pl330_chan_queue_busy = 6,

    pl330_chan_waiting_periph = 7,

    pl330_chan_killing = 8,

    pl330_chan_completing = 9,

    pl330_chan_fault_completing = 14,

    pl330_chan_fault = 15,

} PL330ChanState;

typedef struct PL330State PL330State;

typedef struct PL330Chan {

    uint32_t src;

    uint32_t dst;

    uint32_t pc;

    uint32_t control;

    uint32_t status;

    uint32_t lc[2];

    uint32_t fault_type;

    uint32_t watchdog_timer;

    bool ns;

    uint8_t request_flag;

    uint8_t wakeup;

    uint8_t wfp_sbp;

    uint8_t state;

    uint8_t stall;

    bool is_manager;

    PL330State *parent;

    uint8_t tag;

} PL330Chan;

static const VMStateDescription vmstate_pl330_chan = {

    .name = "pl330_chan",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_UINT32(src, PL330Chan),

        VMSTATE_UINT32(dst, PL330Chan),

        VMSTATE_UINT32(pc, PL330Chan),

        VMSTATE_UINT32(control, PL330Chan),

        VMSTATE_UINT32(status, PL330Chan),

        VMSTATE_UINT32_ARRAY(lc, PL330Chan, 2),

        VMSTATE_UINT32(fault_type, PL330Chan),

        VMSTATE_UINT32(watchdog_timer, PL330Chan),

        VMSTATE_BOOL(ns, PL330Chan),

        VMSTATE_UINT8(request_flag, PL330Chan),

        VMSTATE_UINT8(wakeup, PL330Chan),

        VMSTATE_UINT8(wfp_sbp, PL330Chan),

        VMSTATE_UINT8(state, PL330Chan),

        VMSTATE_UINT8(stall, PL330Chan),

        VMSTATE_END_OF_LIST()

    }

};

typedef struct PL330Fifo {

    uint8_t *buf;

    uint8_t *tag;

    uint32_t head;

    uint32_t num;

    uint32_t buf_size;

} PL330Fifo;

static const VMStateDescription vmstate_pl330_fifo = {

    .name = "pl330_chan",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_VBUFFER_UINT32(buf, PL330Fifo, 1, NULL, 0, buf_size),

        VMSTATE_VBUFFER_UINT32(tag, PL330Fifo, 1, NULL, 0, buf_size),

        VMSTATE_UINT32(head, PL330Fifo),

        VMSTATE_UINT32(num, PL330Fifo),

        VMSTATE_UINT32(buf_size, PL330Fifo),

        VMSTATE_END_OF_LIST()

    }

};

typedef struct PL330QueueEntry {

    uint32_t addr;

    uint32_t len;

    uint8_t n;

    bool inc;

    bool z;

    uint8_t tag;

    uint8_t seqn;

} PL330QueueEntry;

static const VMStateDescription vmstate_pl330_queue_entry = {

    .name = "pl330_queue_entry",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_UINT32(addr, PL330QueueEntry),

        VMSTATE_UINT32(len, PL330QueueEntry),

        VMSTATE_UINT8(n, PL330QueueEntry),

        VMSTATE_BOOL(inc, PL330QueueEntry),

        VMSTATE_BOOL(z, PL330QueueEntry),

        VMSTATE_UINT8(tag, PL330QueueEntry),

        VMSTATE_UINT8(seqn, PL330QueueEntry),

        VMSTATE_END_OF_LIST()

    }

};

typedef struct PL330Queue {

    PL330State *parent;

    PL330QueueEntry *queue;

    uint32_t queue_size;

} PL330Queue;

static const VMStateDescription vmstate_pl330_queue = {

    .name = "pl330_queue",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_STRUCT_VARRAY_UINT32(queue, PL330Queue, queue_size, 1,

                                 vmstate_pl330_queue_entry, PL330QueueEntry),

        VMSTATE_END_OF_LIST()

    }

};

struct PL330State {

    SysBusDevice busdev;

    MemoryRegion iomem;

    qemu_irq irq_abort;

    qemu_irq *irq;

    /* Config registers. cfg[5] = CfgDn. */

    uint32_t cfg[6];

#define EVENT_SEC_STATE 3

#define PERIPH_SEC_STATE 4

    /* cfg 0 bits and pieces */

    uint32_t num_chnls;

    uint8_t num_periph_req;

    uint8_t num_events;

    uint8_t mgr_ns_at_rst;

    /* cfg 1 bits and pieces */

    uint8_t i_cache_len;

    uint8_t num_i_cache_lines;

    /* CRD bits and pieces */

    uint8_t data_width;

    uint8_t wr_cap;

    uint8_t wr_q_dep;

    uint8_t rd_cap;

    uint8_t rd_q_dep;

    uint16_t data_buffer_dep;

    PL330Chan manager;

    PL330Chan *chan;

    PL330Fifo fifo;

    PL330Queue read_queue;

    PL330Queue write_queue;

    uint8_t *lo_seqn;

    uint8_t *hi_seqn;

    QEMUTimer *timer; /* is used for restore dma. */

    uint32_t inten;

    uint32_t int_status;

    uint32_t ev_status;

    uint32_t dbg[2];

    uint8_t debug_status;

    uint8_t num_faulting;

    uint8_t periph_busy[PL330_PERIPH_NUM];

};

#define TYPE_PL330 "pl330"

#define PL330(obj) OBJECT_CHECK(PL330State, (obj), TYPE_PL330)

static const VMStateDescription vmstate_pl330 = {

    .name = "pl330",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_STRUCT(manager, PL330State, 0, vmstate_pl330_chan, PL330Chan),

        VMSTATE_STRUCT_VARRAY_UINT32(chan, PL330State, num_chnls, 0,

                                     vmstate_pl330_chan, PL330Chan),

        VMSTATE_VBUFFER_UINT32(lo_seqn, PL330State, 1, NULL, 0, num_chnls),

        VMSTATE_VBUFFER_UINT32(hi_seqn, PL330State, 1, NULL, 0, num_chnls),

        VMSTATE_STRUCT(fifo, PL330State, 0, vmstate_pl330_fifo, PL330Fifo),

        VMSTATE_STRUCT(read_queue, PL330State, 0, vmstate_pl330_queue,

                       PL330Queue),

        VMSTATE_STRUCT(write_queue, PL330State, 0, vmstate_pl330_queue,

                       PL330Queue),

        VMSTATE_TIMER(timer, PL330State),

        VMSTATE_UINT32(inten, PL330State),

        VMSTATE_UINT32(int_status, PL330State),

        VMSTATE_UINT32(ev_status, PL330State),

        VMSTATE_UINT32_ARRAY(dbg, PL330State, 2),

        VMSTATE_UINT8(debug_status, PL330State),

        VMSTATE_UINT8(num_faulting, PL330State),

        VMSTATE_UINT8_ARRAY(periph_busy, PL330State, PL330_PERIPH_NUM),

        VMSTATE_END_OF_LIST()

    }

};

typedef struct PL330InsnDesc {

    /* OPCODE of the instruction */

    uint8_t opcode;

    /* Mask so we can select several sibling instructions, such as

       DMALD, DMALDS and DMALDB */

    uint8_t opmask;

    /* Size of instruction in bytes */

    uint8_t size;

    /* Interpreter */

    void (*exec)(PL330Chan *, uint8_t opcode, uint8_t *args, int len);

} PL330InsnDesc;

/* MFIFO Implementation

 *

 * MFIFO is implemented as a cyclic buffer of BUF_SIZE size. Tagged bytes are

 * stored in this buffer. Data is stored in BUF field, tags - in the

 * corresponding array elements of TAG field.

 */

/* Initialize queue. */

static void pl330_fifo_init(PL330Fifo *s, uint32_t size)

{

    s->buf = g_malloc0(size);

    s->tag = g_malloc0(size);

    s->buf_size = size;

}

/* Cyclic increment */

static inline int pl330_fifo_inc(PL330Fifo *s, int x)

{

    return (x + 1) % s->buf_size;

}

/* Number of empty bytes in MFIFO */

static inline int pl330_fifo_num_free(PL330Fifo *s)

{

    return s->buf_size - s->num;

}

/* Push LEN bytes of data stored in BUF to MFIFO and tag it with TAG.

 * Zero returned on success, PL330_FIFO_STALL if there is no enough free

 * space in MFIFO to store requested amount of data. If push was unsuccessful

 * no data is stored to MFIFO.

 */

static int pl330_fifo_push(PL330Fifo *s, uint8_t *buf, int len, uint8_t tag)

{

    int i;

    if (s->buf_size - s->num < len) {

        return PL330_FIFO_STALL;

    }

    for (i = 0; i < len; i++) {

        int push_idx = (s->head + s->num + i) % s->buf_size;

        s->buf[push_idx] = buf[i];

        s->tag[push_idx] = tag;

    }

    s->num += len;

    return PL330_FIFO_OK;

}

/* Get LEN bytes of data from MFIFO and store it to BUF. Tag value of each

 * byte is verified. Zero returned on success, PL330_FIFO_ERR on tag mismatch

 * and PL330_FIFO_STALL if there is no enough data in MFIFO. If get was

 * unsuccessful no data is removed from MFIFO.

 */

static int pl330_fifo_get(PL330Fifo *s, uint8_t *buf, int len, uint8_t tag)

{

    int i;

    if (s->num < len) {

        return PL330_FIFO_STALL;

    }

    for (i = 0; i < len; i++) {

        if (s->tag[s->head] == tag) {

            int get_idx = (s->head + i) % s->buf_size;

            buf[i] = s->buf[get_idx];

        } else { /* Tag mismatch - Rollback transaction */

            return PL330_FIFO_ERR;

        }

    }

    s->head = (s->head + len) % s->buf_size;

    s->num -= len;

    return PL330_FIFO_OK;

}

/* Reset MFIFO. This completely erases all data in it. */

static inline void pl330_fifo_reset(PL330Fifo *s)

{

    s->head = 0;

    s->num = 0;

}

/* Return tag of the first byte stored in MFIFO. If MFIFO is empty

 * PL330_UNTAGGED is returned.

 */

static inline uint8_t pl330_fifo_tag(PL330Fifo *s)

{

    return (!s->num) ? PL330_UNTAGGED : s->tag[s->head];

}

/* Returns non-zero if tag TAG is present in fifo or zero otherwise */

static int pl330_fifo_has_tag(PL330Fifo *s, uint8_t tag)

{

    int i, n;

    i = s->head;

    for (n = 0; n < s->num; n++) {

        if (s->tag[i] == tag) {

            return 1;

        }

        i = pl330_fifo_inc(s, i);

    }

    return 0;

}

/* Remove all entry tagged with TAG from MFIFO */

static void pl330_fifo_tagged_remove(PL330Fifo *s, uint8_t tag)

{

    int i, t, n;

    t = i = s->head;

    for (n = 0; n < s->num; n++) {

        if (s->tag[i] != tag) {

            s->buf[t] = s->buf[i];

            s->tag[t] = s->tag[i];

            t = pl330_fifo_inc(s, t);

        } else {

            s->num = s->num - 1;

        }

        i = pl330_fifo_inc(s, i);

    }

}

/* Read-Write Queue implementation

 *

 * A Read-Write Queue stores up to QUEUE_SIZE instructions (loads or stores).

 * Each instruction is described by source (for loads) or destination (for

 * stores) address ADDR, width of data to be loaded/stored LEN, number of

 * stores/loads to be performed N, INC bit, Z bit and TAG to identify channel

 * this instruction belongs to. Queue does not store any information about

 * nature of the instruction: is it load or store. PL330 has different queues

 * for loads and stores so this is already known at the top level where it

 * matters.

 *

 * Queue works as FIFO for instructions with equivalent tags, but can issue

 * instructions with different tags in arbitrary order. SEQN field attached to

 * each instruction helps to achieve this. For each TAG queue contains

 * instructions with consecutive SEQN values ranging from LO_SEQN[TAG] to

 * HI_SEQN[TAG]-1 inclusive. SEQN is 8-bit unsigned integer, so SEQN=255 is

 * followed by SEQN=0.

 *

 * Z bit indicates that zeroes should be stored. No MFIFO fetches are performed

 * in this case.

 */

static void pl330_queue_reset(PL330Queue *s)

{

    int i;

    for (i = 0; i < s->queue_size; i++) {

        s->queue[i].tag = PL330_UNTAGGED;

    }

}

/* Initialize queue */

static void pl330_queue_init(PL330Queue *s, int size, PL330State *parent)

{

    s->parent = parent;

    s->queue = g_new0(PL330QueueEntry, size);

    s->queue_size = size;

}

/* Returns pointer to an empty slot or NULL if queue is full */

static PL330QueueEntry *pl330_queue_find_empty(PL330Queue *s)

{

    int i;

    for (i = 0; i < s->queue_size; i++) {

        if (s->queue[i].tag == PL330_UNTAGGED) {

            return &s->queue[i];

        }

    }

    return NULL;

}

/* Put instruction in queue.

 * Return value:

 * - zero - OK

 * - non-zero - queue is full

 */

static int pl330_queue_put_insn(PL330Queue *s, uint32_t addr,

                                int len, int n, bool inc, bool z, uint8_t tag)

{

    PL330QueueEntry *entry = pl330_queue_find_empty(s);

    if (!entry) {

        return 1;

    }

    entry->tag = tag;

    entry->addr = addr;

    entry->len = len;

    entry->n = n;

    entry->z = z;

    entry->inc = inc;

    entry->seqn = s->parent->hi_seqn[tag];

    s->parent->hi_seqn[tag]++;

    return 0;

}

/* Returns a pointer to queue slot containing instruction which satisfies

 *  following conditions:

 *   - it has valid tag value (not PL330_UNTAGGED)

 *   - if enforce_seq is set it has to be issuable without violating queue

 *     logic (see above)

 *   - if TAG argument is not PL330_UNTAGGED this instruction has tag value

 *     equivalent to the argument TAG value.

 *  If such instruction cannot be found NULL is returned.

 */

static PL330QueueEntry *pl330_queue_find_insn(PL330Queue *s, uint8_t tag,

                                              bool enforce_seq)

{

    int i;

    for (i = 0; i < s->queue_size; i++) {

        if (s->queue[i].tag != PL330_UNTAGGED) {

            if ((!enforce_seq ||

                    s->queue[i].seqn == s->parent->lo_seqn[s->queue[i].tag]) &&

                    (s->queue[i].tag == tag || tag == PL330_UNTAGGED ||

                    s->queue[i].z)) {

                return &s->queue[i];

            }

        }

    }

    return NULL;

}

/* Removes instruction from queue. */

static inline void pl330_queue_remove_insn(PL330Queue *s, PL330QueueEntry *e)

{

    s->parent->lo_seqn[e->tag]++;

    e->tag = PL330_UNTAGGED;

}

/* Removes all instructions tagged with TAG from queue. */

static inline void pl330_queue_remove_tagged(PL330Queue *s, uint8_t tag)

{

    int i;

    for (i = 0; i < s->queue_size; i++) {

        if (s->queue[i].tag == tag) {

            s->queue[i].tag = PL330_UNTAGGED;

        }

    }

}

/* DMA instruction execution engine */

/* Moves DMA channel to the FAULT state and updates it's status. */

static inline void pl330_fault(PL330Chan *ch, uint32_t flags)

{

    DB_PRINT("ch: %p, flags: %x\n", ch, flags);

    ch->fault_type |= flags;

    if (ch->state == pl330_chan_fault) {

        return;

    }

    ch->state = pl330_chan_fault;

    ch->parent->num_faulting++;

    if (ch->parent->num_faulting == 1) {

        DB_PRINT("abort interrupt raised\n");

        qemu_irq_raise(ch->parent->irq_abort);

    }

}

/*

 * For information about instructions see PL330 Technical Reference Manual.

 *

 * Arguments:

 *   CH - channel executing the instruction

 *   OPCODE - opcode

 *   ARGS - array of 8-bit arguments

 *   LEN - number of elements in ARGS array

 */

static void pl330_dmaaddh(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint16_t im = (((uint16_t)args[1]) << 8) | ((uint16_t)args[0]);

    uint8_t ra = (opcode >> 1) & 1;

    if (ch->is_manager) {

        pl330_fault(ch, PL330_FAULT_UNDEF_INSTR);

        return;

    }

    if (ra) {

        ch->dst += im;

    } else {

        ch->src += im;

    }

}

static void pl330_dmaend(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    PL330State *s = ch->parent;

    if (ch->state == pl330_chan_executing && !ch->is_manager) {

        /* Wait for all transfers to complete */

        if (pl330_fifo_has_tag(&s->fifo, ch->tag) ||

            pl330_queue_find_insn(&s->read_queue, ch->tag, false) != NULL ||

            pl330_queue_find_insn(&s->write_queue, ch->tag, false) != NULL) {

            ch->stall = 1;

            return;

        }

    }

    DB_PRINT("DMA ending!\n");

    pl330_fifo_tagged_remove(&s->fifo, ch->tag);

    pl330_queue_remove_tagged(&s->read_queue, ch->tag);

    pl330_queue_remove_tagged(&s->write_queue, ch->tag);

    ch->state = pl330_chan_stopped;

}

static void pl330_dmaflushp(PL330Chan *ch, uint8_t opcode,

                                            uint8_t *args, int len)

{

    uint8_t periph_id;

    if (args[0] & 7) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    periph_id = (args[0] >> 3) & 0x1f;

    if (periph_id >= ch->parent->num_periph_req) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_PNS] & (1 << periph_id))) {

        pl330_fault(ch, PL330_FAULT_CH_PERIPH_ERR);

        return;

    }

    /* Do nothing */

}

static void pl330_dmago(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t chan_id;

    uint8_t ns;

    uint32_t pc;

    PL330Chan *s;

    DB_PRINT("\n");

    if (!ch->is_manager) {

        pl330_fault(ch, PL330_FAULT_UNDEF_INSTR);

        return;

    }

    ns = !!(opcode & 2);

    chan_id = args[0] & 7;

    if ((args[0] >> 3)) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (chan_id >= ch->parent->num_chnls) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    pc = (((uint32_t)args[4]) << 24) | (((uint32_t)args[3]) << 16) |

         (((uint32_t)args[2]) << 8)  | (((uint32_t)args[1]));

    if (ch->parent->chan[chan_id].state != pl330_chan_stopped) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !ns) {

        pl330_fault(ch, PL330_FAULT_DMAGO_ERR);

        return;

    }

    s = &ch->parent->chan[chan_id];

    s->ns = ns;

    s->pc = pc;

    s->state = pl330_chan_executing;

}

static void pl330_dmald(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t bs = opcode & 3;

    uint32_t size, num;

    bool inc;

    if (bs == 2) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if ((bs == 1 && ch->request_flag == PL330_BURST) ||

        (bs == 3 && ch->request_flag == PL330_SINGLE)) {

        /* Perform NOP */

        return;

    }

    if (bs == 1 && ch->request_flag == PL330_SINGLE) {

        num = 1;

    } else {

        num = ((ch->control >> 4) & 0xf) + 1;

    }

    size = (uint32_t)1 << ((ch->control >> 1) & 0x7);

    inc = !!(ch->control & 1);

    ch->stall = pl330_queue_put_insn(&ch->parent->read_queue, ch->src,

                                    size, num, inc, 0, ch->tag);

    if (!ch->stall) {

        DB_PRINT("channel:%d address:%08x size:%d num:%d %c\n",

                 ch->tag, ch->src, size, num, inc ? 'Y' : 'N');

        ch->src += inc ? size * num - (ch->src & (size - 1)) : 0;

    }

}

static void pl330_dmaldp(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t periph_id;

    if (args[0] & 7) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    periph_id = (args[0] >> 3) & 0x1f;

    if (periph_id >= ch->parent->num_periph_req) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_PNS] & (1 << periph_id))) {

        pl330_fault(ch, PL330_FAULT_CH_PERIPH_ERR);

        return;

    }

    pl330_dmald(ch, opcode, args, len);

}

static void pl330_dmalp(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t lc = (opcode & 2) >> 1;

    ch->lc[lc] = args[0];

}

static void pl330_dmakill(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    if (ch->state == pl330_chan_fault ||

        ch->state == pl330_chan_fault_completing) {

        /* This is the only way for a channel to leave the faulting state */

        ch->fault_type = 0;

        ch->parent->num_faulting--;

        if (ch->parent->num_faulting == 0) {

            DB_PRINT("abort interrupt lowered\n");

            qemu_irq_lower(ch->parent->irq_abort);

        }

    }

    ch->state = pl330_chan_killing;

    pl330_fifo_tagged_remove(&ch->parent->fifo, ch->tag);

    pl330_queue_remove_tagged(&ch->parent->read_queue, ch->tag);

    pl330_queue_remove_tagged(&ch->parent->write_queue, ch->tag);

    ch->state = pl330_chan_stopped;

}

static void pl330_dmalpend(PL330Chan *ch, uint8_t opcode,

                                    uint8_t *args, int len)

{

    uint8_t nf = (opcode & 0x10) >> 4;

    uint8_t bs = opcode & 3;

    uint8_t lc = (opcode & 4) >> 2;

    if (bs == 2) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if ((bs == 1 && ch->request_flag == PL330_BURST) ||

        (bs == 3 && ch->request_flag == PL330_SINGLE)) {

        /* Perform NOP */

        return;

    }

    if (!nf || ch->lc[lc]) {

        if (nf) {

            ch->lc[lc]--;

        }

        DB_PRINT("loop reiteration\n");

        ch->pc -= args[0];

        ch->pc -= len + 1;

        /* "ch->pc -= args[0] + len + 1" is incorrect when args[0] == 256 */

    } else {

        DB_PRINT("loop fallthrough\n");

    }

}

static void pl330_dmamov(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t rd = args[0] & 7;

    uint32_t im;

    if ((args[0] >> 3)) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    im = (((uint32_t)args[4]) << 24) | (((uint32_t)args[3]) << 16) |

         (((uint32_t)args[2]) << 8)  | (((uint32_t)args[1]));

    switch (rd) {

    case 0:

        ch->src = im;

        break;

    case 1:

        ch->control = im;

        break;

    case 2:

        ch->dst = im;

        break;

    default:

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

}

static void pl330_dmanop(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    /* NOP is NOP. */

}

static void pl330_dmarmb(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

   if (pl330_queue_find_insn(&ch->parent->read_queue, ch->tag, false)) {

        ch->state = pl330_chan_at_barrier;

        ch->stall = 1;

        return;

    } else {

        ch->state = pl330_chan_executing;

    }

}

static void pl330_dmasev(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t ev_id;

    if (args[0] & 7) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    ev_id = (args[0] >> 3) & 0x1f;

    if (ev_id >= ch->parent->num_events) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_INS] & (1 << ev_id))) {

        pl330_fault(ch, PL330_FAULT_EVENT_ERR);

        return;

    }

    if (ch->parent->inten & (1 << ev_id)) {

        ch->parent->int_status |= (1 << ev_id);

        DB_PRINT("event interrupt raised %d\n", ev_id);

        qemu_irq_raise(ch->parent->irq[ev_id]);

    }

    ch->parent->ev_status |= (1 << ev_id);

}

static void pl330_dmast(PL330Chan *ch, uint8_t opcode, uint8_t *args, int len)

{

    uint8_t bs = opcode & 3;

    uint32_t size, num;

    bool inc;

    if (bs == 2) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if ((bs == 1 && ch->request_flag == PL330_BURST) ||

        (bs == 3 && ch->request_flag == PL330_SINGLE)) {

        /* Perform NOP */

        return;

    }

    num = ((ch->control >> 18) & 0xf) + 1;

    size = (uint32_t)1 << ((ch->control >> 15) & 0x7);

    inc = !!((ch->control >> 14) & 1);

    ch->stall = pl330_queue_put_insn(&ch->parent->write_queue, ch->dst,

                                    size, num, inc, 0, ch->tag);

    if (!ch->stall) {

        DB_PRINT("channel:%d address:%08x size:%d num:%d %c\n",

                 ch->tag, ch->dst, size, num, inc ? 'Y' : 'N');

        ch->dst += inc ? size * num - (ch->dst & (size - 1)) : 0;

    }

}

static void pl330_dmastp(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    uint8_t periph_id;

    if (args[0] & 7) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    periph_id = (args[0] >> 3) & 0x1f;

    if (periph_id >= ch->parent->num_periph_req) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_PNS] & (1 << periph_id))) {

        pl330_fault(ch, PL330_FAULT_CH_PERIPH_ERR);

        return;

    }

    pl330_dmast(ch, opcode, args, len);

}

static void pl330_dmastz(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    uint32_t size, num;

    bool inc;

    num = ((ch->control >> 18) & 0xf) + 1;

    size = (uint32_t)1 << ((ch->control >> 15) & 0x7);

    inc = !!((ch->control >> 14) & 1);

    ch->stall = pl330_queue_put_insn(&ch->parent->write_queue, ch->dst,

                                    size, num, inc, 1, ch->tag);

    if (inc) {

        ch->dst += size * num;

    }

}

static void pl330_dmawfe(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    uint8_t ev_id;

    int i;

    if (args[0] & 5) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    ev_id = (args[0] >> 3) & 0x1f;

    if (ev_id >= ch->parent->num_events) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_INS] & (1 << ev_id))) {

        pl330_fault(ch, PL330_FAULT_EVENT_ERR);

        return;

    }

    ch->wakeup = ev_id;

    ch->state = pl330_chan_waiting_event;

    if (~ch->parent->inten & ch->parent->ev_status & 1 << ev_id) {

        ch->state = pl330_chan_executing;

        /* If anyone else is currently waiting on the same event, let them

         * clear the ev_status so they pick up event as well

         */

        for (i = 0; i < ch->parent->num_chnls; ++i) {

            PL330Chan *peer = &ch->parent->chan[i];

            if (peer->state == pl330_chan_waiting_event &&

                    peer->wakeup == ev_id) {

                return;

            }

        }

        ch->parent->ev_status &= ~(1 << ev_id);

    } else {

        ch->stall = 1;

    }

}

static void pl330_dmawfp(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    uint8_t bs = opcode & 3;

    uint8_t periph_id;

    if (args[0] & 7) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    periph_id = (args[0] >> 3) & 0x1f;

    if (periph_id >= ch->parent->num_periph_req) {

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->ns && !(ch->parent->cfg[CFG_PNS] & (1 << periph_id))) {

        pl330_fault(ch, PL330_FAULT_CH_PERIPH_ERR);

        return;

    }

    switch (bs) {

    case 0: /* S */

        ch->request_flag = PL330_SINGLE;

        ch->wfp_sbp = 0;

        break;

    case 1: /* P */

        ch->request_flag = PL330_BURST;

        ch->wfp_sbp = 2;

        break;

    case 2: /* B */

        ch->request_flag = PL330_BURST;

        ch->wfp_sbp = 1;

        break;

    default:

        pl330_fault(ch, PL330_FAULT_OPERAND_INVALID);

        return;

    }

    if (ch->parent->periph_busy[periph_id]) {

        ch->state = pl330_chan_waiting_periph;

        ch->stall = 1;

    } else if (ch->state == pl330_chan_waiting_periph) {

        ch->state = pl330_chan_executing;

    }

}

static void pl330_dmawmb(PL330Chan *ch, uint8_t opcode,

                         uint8_t *args, int len)

{

    if (pl330_queue_find_insn(&ch->parent->write_queue, ch->tag, false)) {

        ch->state = pl330_chan_at_barrier;

        ch->stall = 1;

        return;

    } else {

        ch->state = pl330_chan_executing;

    }

}

/* NULL terminated array of the instruction descriptions. */

static const PL330InsnDesc insn_desc[] = {

    { .opcode = 0x54, .opmask = 0xFD, .size = 3, .exec = pl330_dmaaddh, },

    { .opcode = 0x00, .opmask = 0xFF, .size = 1, .exec = pl330_dmaend, },

    { .opcode = 0x35, .opmask = 0xFF, .size = 2, .exec = pl330_dmaflushp, },

    { .opcode = 0xA0, .opmask = 0xFD, .size = 6, .exec = pl330_dmago, },

    { .opcode = 0x04, .opmask = 0xFC, .size = 1, .exec = pl330_dmald, },

    { .opcode = 0x25, .opmask = 0xFD, .size = 2, .exec = pl330_dmaldp, },

    { .opcode = 0x20, .opmask = 0xFD, .size = 2, .exec = pl330_dmalp, },

    /* dmastp  must be before dmalpend in this list, because their maps

     * are overlapping

     */

    { .opcode = 0x29, .opmask = 0xFD, .size = 2, .exec = pl330_dmastp, },

    { .opcode = 0x28, .opmask = 0xE8, .size = 2, .exec = pl330_dmalpend, },

    { .opcode = 0x01, .opmask = 0xFF, .size = 1, .exec = pl330_dmakill, },

    { .opcode = 0xBC, .opmask = 0xFF, .size = 6, .exec = pl330_dmamov, },

    { .opcode = 0x18, .opmask = 0xFF, .size = 1, .exec = pl330_dmanop, },

    { .opcode = 0x12, .opmask = 0xFF, .size = 1, .exec = pl330_dmarmb, },

    { .opcode = 0x34, .opmask = 0xFF, .size = 2, .exec = pl330_dmasev, },

    { .opcode = 0x08, .opmask = 0xFC, .size = 1, .exec = pl330_dmast, },

    { .opcode = 0x0C, .opmask = 0xFF, .size = 1, .exec = pl330_dmastz, },

    { .opcode = 0x36, .opmask = 0xFF, .size = 2, .exec = pl330_dmawfe, },

    { .opcode = 0x30, .opmask = 0xFC, .size = 2, .exec = pl330_dmawfp, },

    { .opcode = 0x13, .opmask = 0xFF, .size = 1, .exec = pl330_dmawmb, },

    { .opcode = 0x00, .opmask = 0x00, .size = 0, .exec = NULL, }

};

/* Instructions which can be issued via debug registers. */

static const PL330InsnDesc debug_insn_desc[] = {

    { .opcode = 0xA0, .opmask = 0xFD, .size = 6, .exec = pl330_dmago, },

    { .opcode = 0x01, .opmask = 0xFF, .size = 1, .exec = pl330_dmakill, },

    { .opcode = 0x34, .opmask = 0xFF, .size = 2, .exec = pl330_dmasev, },

    { .opcode = 0x00, .opmask = 0x00, .size = 0, .exec = NULL, }

};

static inline const PL330InsnDesc *pl330_fetch_insn(PL330Chan *ch)

{

    uint8_t opcode;

    int i;

    dma_memory_read(&address_space_memory, ch->pc, &opcode, 1);

    for (i = 0; insn_desc[i].size; i++) {

        if ((opcode & insn_desc[i].opmask) == insn_desc[i].opcode) {

            return &insn_desc[i];

        }

    }

    return NULL;

}

static inline void pl330_exec_insn(PL330Chan *ch, const PL330InsnDesc *insn)

{

    uint8_t buf[PL330_INSN_MAXSIZE];

    assert(insn->size <= PL330_INSN_MAXSIZE);

    dma_memory_read(&address_space_memory, ch->pc, buf, insn->size);

    insn->exec(ch, buf[0], &buf[1], insn->size - 1);

}

static inline void pl330_update_pc(PL330Chan *ch,

                                   const PL330InsnDesc *insn)

{

    ch->pc += insn->size;

}

/* Try to execute current instruction in channel CH. Number of executed

   instructions is returned (0 or 1). */

static int pl330_chan_exec(PL330Chan *ch)

{

    const PL330InsnDesc *insn;

    if (ch->state != pl330_chan_executing &&

            ch->state != pl330_chan_waiting_periph &&

            ch->state != pl330_chan_at_barrier &&

            ch->state != pl330_chan_waiting_event) {

        DB_PRINT("%d\n", ch->state);

        return 0;

    }

    ch->stall = 0;

    insn = pl330_fetch_insn(ch);

    if (!insn) {

        DB_PRINT("pl330 undefined instruction\n");

        pl330_fault(ch, PL330_FAULT_UNDEF_INSTR);

        return 0;

    }

    pl330_exec_insn(ch, insn);

    if (!ch->stall) {

        pl330_update_pc(ch, insn);

        ch->watchdog_timer = 0;

        return 1;

    /* WDT only active in exec state */

    } else if (ch->state == pl330_chan_executing) {

        ch->watchdog_timer++;

        if (ch->watchdog_timer >= PL330_WATCHDOG_LIMIT) {

            pl330_fault(ch, PL330_FAULT_LOCKUP_ERR);

        }

    }

    return 0;

}

/* Try to execute 1 instruction in each channel, one instruction from read

   queue and one instruction from write queue. Number of successfully executed

   instructions is returned. */

static int pl330_exec_cycle(PL330Chan *channel)

{

    PL330State *s = channel->parent;

    PL330QueueEntry *q;

    int i;

    int num_exec = 0;

    int fifo_res = 0;

    uint8_t buf[PL330_MAX_BURST_LEN];

    /* Execute one instruction in each channel */

    num_exec += pl330_chan_exec(channel);

    /* Execute one instruction from read queue */

    q = pl330_queue_find_insn(&s->read_queue, PL330_UNTAGGED, true);

    if (q != NULL && q->len <= pl330_fifo_num_free(&s->fifo)) {

        int len = q->len - (q->addr & (q->len - 1));

        dma_memory_read(&address_space_memory, q->addr, buf, len);

        if (PL330_ERR_DEBUG > 1) {

            DB_PRINT("PL330 read from memory @%08x (size = %08x):\n",

                      q->addr, len);

            qemu_hexdump((char *)buf, stderr, "", len);

        }

        fifo_res = pl330_fifo_push(&s->fifo, buf, len, q->tag);

        if (fifo_res == PL330_FIFO_OK) {

            if (q->inc) {

                q->addr += len;

            }

            q->n--;

            if (!q->n) {

                pl330_queue_remove_insn(&s->read_queue, q);

            }

            num_exec++;

        }

    }

    /* Execute one instruction from write queue. */

    q = pl330_queue_find_insn(&s->write_queue, pl330_fifo_tag(&s->fifo), true);

    if (q != NULL) {

        int len = q->len - (q->addr & (q->len - 1));

        if (q->z) {

            for (i = 0; i < len; i++) {

                buf[i] = 0;

            }

        } else {

            fifo_res = pl330_fifo_get(&s->fifo, buf, len, q->tag);

        }

        if (fifo_res == PL330_FIFO_OK || q->z) {

            dma_memory_write(&address_space_memory, q->addr, buf, len);

            if (PL330_ERR_DEBUG > 1) {

                DB_PRINT("PL330 read from memory @%08x (size = %08x):\n",

                         q->addr, len);

                qemu_hexdump((char *)buf, stderr, "", len);

            }

            if (q->inc) {

                q->addr += len;

            }

            num_exec++;

        } else if (fifo_res == PL330_FIFO_STALL) {

            pl330_fault(&channel->parent->chan[q->tag],

                                PL330_FAULT_FIFOEMPTY_ERR);

        }

        q->n--;

        if (!q->n) {

            pl330_queue_remove_insn(&s->write_queue, q);

        }

    }

    return num_exec;

}

static int pl330_exec_channel(PL330Chan *channel)

{

    int insr_exec = 0;

    /* TODO: Is it all right to execute everything or should we do per-cycle

       simulation? */

    while (pl330_exec_cycle(channel)) {

        insr_exec++;

    }

    /* Detect deadlock */

    if (channel->state == pl330_chan_executing) {

        pl330_fault(channel, PL330_FAULT_LOCKUP_ERR);

    }

    /* Situation when one of the queues has deadlocked but all channels

     * have finished their programs should be impossible.

     */

    return insr_exec;

}

static inline void pl330_exec(PL330State *s)

{

    DB_PRINT("\n");

    int i, insr_exec;

    do {

        insr_exec = pl330_exec_channel(&s->manager);

        for (i = 0; i < s->num_chnls; i++) {

            insr_exec += pl330_exec_channel(&s->chan[i]);

        }

    } while (insr_exec);

}

static void pl330_exec_cycle_timer(void *opaque)

{

    PL330State *s = (PL330State *)opaque;

    pl330_exec(s);

}

/* Stop or restore dma operations */

static void pl330_dma_stop_irq(void *opaque, int irq, int level)

{

    PL330State *s = (PL330State *)opaque;

    if (s->periph_busy[irq] != level) {

        s->periph_busy[irq] = level;

        qemu_mod_timer(s->timer, qemu_get_clock_ns(vm_clock));

    }

}

static void pl330_debug_exec(PL330State *s)

{

    uint8_t args[5];

    uint8_t opcode;

    uint8_t chan_id;

    int i;

    PL330Chan *ch;

    const PL330InsnDesc *insn;

    s->debug_status = 1;

    chan_id = (s->dbg[0] >>  8) & 0x07;

    opcode  = (s->dbg[0] >> 16) & 0xff;

    args[0] = (s->dbg[0] >> 24) & 0xff;

    args[1] = (s->dbg[1] >>  0) & 0xff;

    args[2] = (s->dbg[1] >>  8) & 0xff;

    args[3] = (s->dbg[1] >> 16) & 0xff;

    args[4] = (s->dbg[1] >> 24) & 0xff;

    DB_PRINT("chan id: %d\n", chan_id);

    if (s->dbg[0] & 1) {

        ch = &s->chan[chan_id];

    } else {

        ch = &s->manager;

    }

    insn = NULL;

    for (i = 0; debug_insn_desc[i].size; i++) {

        if ((opcode & debug_insn_desc[i].opmask) == debug_insn_desc[i].opcode) {

            insn = &debug_insn_desc[i];

        }

    }

    if (!insn) {

        pl330_fault(ch, PL330_FAULT_UNDEF_INSTR | PL330_FAULT_DBG_INSTR);

        return ;

    }

    ch->stall = 0;

    insn->exec(ch, opcode, args, insn->size - 1);

    if (ch->fault_type) {

        ch->fault_type |= PL330_FAULT_DBG_INSTR;

    }

    if (ch->stall) {

        qemu_log_mask(LOG_UNIMP, "pl330: stall of debug instruction not "

                      "implemented\n");

    }

    s->debug_status = 0;

}

/* IOMEM mapped registers */

static void pl330_iomem_write(void *opaque, hwaddr offset,

                              uint64_t value, unsigned size)

{

    PL330State *s = (PL330State *) opaque;

    uint32_t i;

    DB_PRINT("addr: %08x data: %08x\n", (unsigned)offset, (unsigned)value);

    switch (offset) {

    case PL330_REG_INTEN:

        s->inten = value;

        break;

    case PL330_REG_INTCLR:

        for (i = 0; i < s->num_events; i++) {

            if (s->int_status & s->inten & value & (1 << i)) {

                DB_PRINT("event interrupt lowered %d\n", i);

                qemu_irq_lower(s->irq[i]);

            }

        }

        s->ev_status &= ~(value & s->inten);

        s->int_status &= ~(value & s->inten);

        break;

    case PL330_REG_DBGCMD:

        if ((value & 3) == 0) {

            pl330_debug_exec(s);

            pl330_exec(s);

        } else {

            qemu_log_mask(LOG_GUEST_ERROR, "pl330: write of illegal value %u "

                          "for offset " TARGET_FMT_plx "\n", (unsigned)value,

                          offset);

        }

        break;

    case PL330_REG_DBGINST0:

        DB_PRINT("s->dbg[0] = %08x\n", (unsigned)value);

        s->dbg[0] = value;

        break;