/**
* Try to get "desired_ntokens" number of tokens from the given
* filestream f. Store them (destructively) in the given list
* "tokens" of dynamically created extstring_t objects. Store in
* "gotten_ntokens" the actual number of tokens that we got.
*/
int
bebop_get_tokens (list_t* tokens,
int* gotten_ntokens,
FILE* f,
const int desired_ntokens,
const char delimiters[],
const int ndelimiters)
{
list_t current = *tokens;
list_t outlist = *tokens;
if (desired_ntokens < 0)
{
bebop_error ("bebop_get_tokens",
"desired_ntokens = %d < 0",
desired_ntokens);
return -1;
}
for (*gotten_ntokens = 0;
*gotten_ntokens < desired_ntokens;
(*gotten_ntokens)++)
{
extstring_t* token = NULL;
int result = 0;
if (list_empty_p (current))
/* We're out of nodes to reuse, so we have to create a new
extstring_t */
token = extstring_create (0);
else
token = list_car (current);
/* Try to get the next token */
result = bebop_next_token (token, f, delimiters, ndelimiters);
if (result != 0)
{
extstring_destroy (token);
break;
}
else
{
if (list_empty_p (current))
outlist = list_append_node (outlist, token);
else
{
list_set_car (current, token);
current = list_cdr (current);
}
}
}
return 0;
}
/* If no request is currently being processed and there's new requests in
the queue, process the first one. This can be called from an interrupt
or the normal kernel context. */
void do_request(blkreq_t *req)
{
fd_dev_t *dev;
u_long track, sect, cyl, head, big_sect, sects;
u_long flags;
int i;
save_flags(flags);
/* This label is used to eliminate tail-recursion. */
top:
cli();
if(current_req != NULL)
{
if(req != NULL)
append_node(&fd_reqs, &req->node);
load_flags(flags);
return;
}
for(i = 0; i < 2; i++)
{
if(fd_devs[i].recalibrate)
{
fdc_recal(&fd_devs[i]);
if(req != NULL)
append_node(&fd_reqs, &req->node);
load_flags(flags);
return;
}
}
if(req == NULL)
{
if(!list_empty_p(&fd_reqs))
{
req = (blkreq_t *)fd_reqs.head;
remove_node(&req->node);
}
else
{
load_flags(flags);
return;
}
}
current_req = req;
#if 0
req->retries = 0;
#endif
load_flags(flags);
dev = REQ_FD_DEV(req);
DB(("fd:do_request: req=%p drive=%d block=%d nblocks=%d cmd=%d buf=%p\n",
req, dev->drvno, req->block, req->nblocks, req->command, req->buf));
switch(req->command)
{
case FD_CMD_SEEK: /* We wanna MOVE DA HEAD! */
/* Do da seek. */
if(fdc_seek(dev, req->block) == FALSE)
{
handle_error("FD_CMD_SEEK, seek");
goto top;
break;
}
/* Then Sense Interrupt Status */
if(fdc_sense() == FALSE)
{
handle_error("FD_CMD_SEEK, fdc_sense");
goto top;
break;
}
/* and now we have to Read the ID */
if(fdc_read_id(dev) == FALSE)
{
handle_error("FD_CMD_SEEK, read_id");
goto top;
break;
}
fd_end_request(0);
req = NULL;
goto top;
case FD_CMD_TIMER:
fd_end_request(0);
req = NULL;
goto top;
}
if(req->block >= dev->total_blocks)
{
kprintf("fd: Device %s (%p) doesn't have a block %d!\n",
dev->name, dev, req->block);
fd_end_request(-1);
req = NULL;
goto top;
}
big_sect = req->block;
sects = req->nblocks;
track = big_sect / dev->disk_p->sectors;
sect = big_sect % dev->disk_p->sectors + 1;
head = track % dev->disk_p->heads;
cyl = track / dev->disk_p->heads;
DB(("fd:do_request: cyl=%d sect=%d head=%d sects=%d\n", cyl, sect, head, sects));
switch(req->command)
{
case FD_CMD_READ: /* We wanna READ the floppy! */
#if 0
fd_end_request(0);
req = NULL;
goto top;
#endif
/* We need to seek to the right cylinder. */
if(fdc_seek(dev, cyl) == FALSE)
{
handle_error("FD_CMD_READ, seek");
goto top;
break;
}
/* Then Sense Interrupt Status */
if(fdc_sense() == FALSE)
{
handle_error("FD_CMD_READ, fdc_sense");
goto top;
break;
}
/* and now we have to Read the ID */
if(fdc_read_id(dev) == FALSE)
{
handle_error("FD_CMD_READ, read_id");
goto top;
break;
}
#define TPA(XX) ((u_long)TO_PHYSICAL(XX))
/* Tell the DMA what to do, and hope for the best! */
/* Should move this inside fdc, in fdc_read() i think */
DMAbuf.Buffer = track_buf;
DMAbuf.Page = (u_int8)((TPA(track_buf) >> 16) & 0xff);
DMAbuf.Offset = (u_int16)(TPA(track_buf) & 0xffff);
DMAbuf.Len = (u_int16)(dev->disk_p->sectors * dev->disk_p->heads *
FD_SECTSIZ) - 1;
DMAbuf.Chan = FLOPPY_DMA;
kernel->setup_dma(&DMAbuf, DMA_READ);
/* Now we issue a read command. */
if(fdc_read(dev, cyl) == FALSE)
{
handle_error("FD_CMD_READ, read");
goto top;
break;
}
break;
case FD_CMD_WRITE: /* We wanna WRITE it too! */
fd_end_request(0);
req = NULL;
goto top;
default:
kprintf("fd:do_request: Unknown command in fd_req, %d\n",
req->command);
fd_end_request(-1);
req = NULL;
goto top;
}
}
/* The scheduler; if possible, switch to the next task in the run queue.
Note that the only reason to *ever* call this function is when the current
task has suspended itself and needs to actually stop executing. Otherwise
just set the `need_resched' flag to TRUE and the scheduler will be called
as soon as is safe.
Never ever *ever* call this from an interrupt handler! It should be safe
to be called from an exception handler though.
Also note that there are no `sliding' priority levels; tasks with high
priority levels can totally block lower-priority tasks. */
void
schedule(void)
{
u_long flags;
save_flags(flags);
cli();
#ifdef PARANOID
if(intr_nest_count != 0)
kprintf("schedule: Oops, being called with intr_nest_count=%d\n",
intr_nest_count);
#endif
/* First reclaim any dead processes.. */
while(zombies)
{
struct task *zombie = (struct task *)zombie_tasks.head;
remove_node(&zombie->node);
reclaim_task(zombie);
zombies--;
}
if((current_task->forbid_count > 0)
&& (current_task->flags & TASK_RUNNING))
{
/* Non pre-emptible task. */
load_flags(flags);
return;
}
need_resched = kernel_module.need_resched = FALSE;
/* Now do the scheduling.. */
if(current_task->flags & TASK_RUNNING)
{
/* Task is still runnable so put it onto the end of the run
queue (paying attention to priority levels). */
remove_node(¤t_task->node);
enqueue_task(&running_tasks, current_task);
}
if(!list_empty_p(&running_tasks))
{
struct task *next = (struct task *)running_tasks.head;
if(next->time_left <= 0)
next->time_left = next->quantum;
if(current_task != next)
{
current_task->cpu_time += timer_ticks - current_task->last_sched;
if(current_task->flags & TASK_ZOMBIE)
{
append_node(&zombie_tasks, ¤t_task->node);
zombies++;
}
next->sched_count++;
next->last_sched = timer_ticks;
current_task = next;
kernel_module.current_task = next;
switch_to_task(next);
#if 1
/* Currently we don't handle the math-copro *at all*; clearing
this flag simply stops us getting dna exceptions.. */
asm volatile ("clts");
#endif
}
}
