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author | Kevin Wolf <kwolf@redhat.com> | 2015-05-21 15:19:35 +0200 |
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committer | John Snow <jsnow@redhat.com> | 2015-06-02 13:34:44 -0400 |
commit | d275b33d76c8ed9d5a3dca22ea0fdec8d5a5c8e6 (patch) | |
tree | bf46ebbe3b048c111f0c11ddd8e13ec8fcc8acf3 /hw | |
parent | 5b0a25e8d2f15f89255c745c71d297b5b24d138c (diff) | |
download | hqemu-d275b33d76c8ed9d5a3dca22ea0fdec8d5a5c8e6.zip hqemu-d275b33d76c8ed9d5a3dca22ea0fdec8d5a5c8e6.tar.gz |
fdc: Code cleanup in fdctrl_write_data()
Factor out a few common lines of code, reformat, improve comments.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 1432214378-31891-6-git-send-email-kwolf@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/block/fdc.c | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/hw/block/fdc.c b/hw/block/fdc.c index e3515a1..1cc1e3a 100644 --- a/hw/block/fdc.c +++ b/hw/block/fdc.c @@ -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; |