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authorKevin Wolf <kwolf@redhat.com>2015-05-21 15:19:35 +0200
committerJohn Snow <jsnow@redhat.com>2015-06-02 13:34:44 -0400
commitd275b33d76c8ed9d5a3dca22ea0fdec8d5a5c8e6 (patch)
treebf46ebbe3b048c111f0c11ddd8e13ec8fcc8acf3 /hw/block/fdc.c
parent5b0a25e8d2f15f89255c745c71d297b5b24d138c (diff)
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/block/fdc.c')
-rw-r--r--hw/block/fdc.c63
1 files changed, 39 insertions, 24 deletions
diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index e3515a1bf8..1cc1e3a984 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;