Commit d275b33d authored by Kevin Wolf's avatar Kevin Wolf Committed by John Snow
Browse files

fdc: Code cleanup in fdctrl_write_data() 



Factor out a few common lines of code, reformat, improve comments.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarJohn Snow <jsnow@redhat.com>
Message-id: 1432214378-31891-6-git-send-email-kwolf@redhat.com
Signed-off-by: default avatarJohn Snow <jsnow@redhat.com>
parent 5b0a25e8

hw/block/fdc.c

+39 −24
Original line number Diff line number Diff line
@@ -2000,14 +2000,16 @@ static void fdctrl_handle_relative_seek_out(FDCtrl *fdctrl, int direction) 
/*

 * Handlers for the execution phase of each command

 */

static const struct {

typedef struct FDCtrlCommand {

    uint8_t value;

    uint8_t mask;

    const char* name;

    int parameters;

    void (*handler)(FDCtrl *fdctrl, int direction);

    int direction;

} handlers[] = {

} FDCtrlCommand;



static const FDCtrlCommand handlers[] = {

    { FD_CMD_READ, 0x1f, "READ", 8, fdctrl_start_transfer, FD_DIR_READ },

    { FD_CMD_WRITE, 0x3f, "WRITE", 8, fdctrl_start_transfer, FD_DIR_WRITE },

    { FD_CMD_SEEK, 0xff, "SEEK", 2, fdctrl_handle_seek },
@@ -2044,9 +2046,19 @@ static const struct { 
/* Associate command to an index in the 'handlers' array */

static uint8_t command_to_handler[256];



static const FDCtrlCommand *get_command(uint8_t cmd)

{

    int idx;



    idx = command_to_handler[cmd];

    FLOPPY_DPRINTF("%s command\n", handlers[idx].name);

    return &handlers[idx];

}



static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)

{

    FDrive *cur_drv;

    const FDCtrlCommand *cmd;

    uint32_t pos;



    /* Reset mode */
@@ -2060,15 +2072,22 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value) 
    }

    fdctrl->dsr &= ~FD_DSR_PWRDOWN;



    FLOPPY_DPRINTF("%s: %02x\n", __func__, value);



    /* If data_len spans multiple sectors, the current position in the FIFO

     * wraps around while fdctrl->data_pos is the real position in the whole

     * request. */

    pos = fdctrl->data_pos++;

    pos %= FD_SECTOR_LEN;

    fdctrl->fifo[pos] = value;



    switch (fdctrl->phase) {

    case FD_PHASE_EXECUTION:

        /* For DMA requests, RQM should be cleared during execution phase, so

         * we would have errored out above. */

        assert(fdctrl->msr & FD_MSR_NONDMA);



        /* FIFO data write */

        pos = fdctrl->data_pos++;

        pos %= FD_SECTOR_LEN;

        fdctrl->fifo[pos] = value;

        if (pos == FD_SECTOR_LEN - 1 ||

            fdctrl->data_pos == fdctrl->data_len) {

            cur_drv = get_cur_drv(fdctrl);
@@ -2084,41 +2103,37 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value) 
                break;

            }

        }

        /* Switch from transfer mode to status mode

         * then from status mode to command mode

         */

        if (fdctrl->data_pos == fdctrl->data_len)



        /* Switch to result phase when done with the transfer */

        if (fdctrl->data_pos == fdctrl->data_len) {

            fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);

        }

        break;



    case FD_PHASE_COMMAND:

        assert(!(fdctrl->msr & FD_MSR_NONDMA));

        assert(fdctrl->data_pos < FD_SECTOR_LEN);



        if (fdctrl->data_pos == 0) {

            /* Command */

            pos = command_to_handler[value & 0xff];

            FLOPPY_DPRINTF("%s command\n", handlers[pos].name);

            fdctrl->data_len = handlers[pos].parameters + 1;

        if (pos == 0) {

            /* The first byte specifies the command. Now we start reading

             * as many parameters as this command requires. */

            cmd = get_command(value);

            fdctrl->data_len = cmd->parameters + 1;

            fdctrl->msr |= FD_MSR_CMDBUSY;

        }



        FLOPPY_DPRINTF("%s: %02x\n", __func__, value);

        pos = fdctrl->data_pos++;

        pos %= FD_SECTOR_LEN;

        fdctrl->fifo[pos] = value;

        if (fdctrl->data_pos == fdctrl->data_len) {

            /* We now have all parameters

             * and will be able to treat the command

             */

            /* We have all parameters now, execute the command */

            fdctrl->phase = FD_PHASE_EXECUTION;



            if (fdctrl->data_state & FD_STATE_FORMAT) {

                fdctrl_format_sector(fdctrl);

                break;

            }



            pos = command_to_handler[fdctrl->fifo[0] & 0xff];

            FLOPPY_DPRINTF("treat %s command\n", handlers[pos].name);

            (*handlers[pos].handler)(fdctrl, handlers[pos].direction);

            cmd = get_command(fdctrl->fifo[0]);

            FLOPPY_DPRINTF("Calling handler for '%s'\n", cmd->name);

            cmd->handler(fdctrl, cmd->direction);

        }

        break;