int kt_kernel_idle_task(void)
{
tm_thread_raise_flag(current_thread, THREAD_KERNEL);
kthread_create(&kthread_pager, "[kpager]", 0, __KT_pager, 0);
strncpy((char *)current_process->command, "[kernel]", 128);
/* wait until init has successfully executed, and then remap. */
while(!(kernel_state_flags & KSF_HAVEEXECED)) {
tm_schedule();
}
printk(1, "[kernel]: remapping lower memory with protection flags...\n");
cpu_interrupt_set(0);
for(addr_t addr = MEMMAP_KERNEL_START; addr < MEMMAP_KERNEL_END; addr += PAGE_SIZE)
{
mm_virtual_changeattr(addr, PAGE_PRESENT | PAGE_WRITE, PAGE_SIZE);
}
cpu_interrupt_set(1);
/* Now enter the main idle loop, waiting to do periodic cleanup */
printk(0, "[idle]: entering background loop\n");
for(;;) {
assert(!current_thread->held_locks);
int r=1;
if(__current_cpu->work.count > 0)
r=workqueue_dowork(&__current_cpu->work);
else
tm_schedule();
int status;
int pid = sys_waitpid(-1, &status, WNOHANG);
if(WIFSTOPPED(status)) {
sys_kill(pid, SIGKILL);
}
}
}
/* This gets run when the interrupt hasn't returned yet, but it's now maybe 'safe' to
* do things - specifically, we've been "ack'd", and interrupt_level is now
* decremented */
void cpu_interrupt_post_handling(void)
{
if(!current_thread->interrupt_level && !current_thread->system) {
if(current_thread->flags & THREAD_TICKER_DOWORK) {
ticker_dowork(&__current_cpu->ticker);
}
if(current_thread->flags & THREAD_SCHEDULE)
tm_schedule();
if(current_thread->flags & THREAD_EXIT) {
tm_thread_do_exit();
tm_schedule();
}
}
}
void cpu_handle_ipi_reschedule(struct registers *regs)
{
// We don't allow a reschedule request if this cpu has interrupts disabled.
if(!cpu_interrupt_get_flag())
return;
tm_schedule();
}
void tm_thread_enter_system(int sys)
{
// Check for PTRACE event.
if((current_thread->flags & THREAD_PTRACED) && (current_thread->tracee_flags & TRACEE_STOPON_SYSCALL)) {
current_thread->tracee_flags &= ~TRACEE_STOPON_SYSCALL;
current_thread->orig_syscall = sys;
current_thread->syscall_return = 0;
tm_signal_send_thread(current_thread, SIGTRAP);
tm_schedule();
}
current_thread->system=(!sys ? -1 : sys);
}
void tm_thread_exit_system(long sys, long ret)
{
current_thread->system=0;
// Check for PTRACE event.
if((current_thread->flags & THREAD_PTRACED) && (current_thread->tracee_flags & TRACEE_STOPON_SYSCALL)) {
current_thread->tracee_flags &= ~TRACEE_STOPON_SYSCALL;
current_thread->orig_syscall = sys;
current_thread->syscall_return = ret;
tm_signal_send_thread(current_thread, SIGTRAP);
tm_schedule();
}
// If we have a signal, then we've been ignoring it up until now because we were inside a syscall. Set the schedule flag so we can handle that now.
if(tm_thread_got_signal(current_thread))
tm_thread_raise_flag(current_thread, THREAD_SCHEDULE);
}
void __mutex_acquire(struct mutex *m, char *file, int line)
{
assert(m->magic == MUTEX_MAGIC);
if(unlikely(kernel_state_flags & KSF_DEBUGGING))
return;
if(unlikely(current_thread && current_thread->interrupt_level))
panic(PANIC_NOSYNC, "cannot lock a mutex within interrupt context (%s:%d)", file, line);
if(unlikely(kernel_state_flags & KSF_SHUTDOWN)) return;
/* wait until we can set bit 0. once this is done, we have the lock */
#if MUTEX_DEBUG
int timeout = 8000;
#endif
if(unlikely(current_thread && __current_cpu->preempt_disable > 0))
panic(0, "tried to lock schedulable mutex with preempt off");
if(likely(current_thread != NULL))
current_thread->held_locks++;
while(atomic_exchange(&m->lock, true)) {
if(likely(current_thread != NULL)) {
/* are we re-locking ourselves? */
if(m->owner == current_thread)
panic(0, "tried to relock mutex (%s:%d)",
file, line);
/* we can use __current_cpu here, because we're testing if we're the idle
* thread, and the idle thread never migrates. */
if(current_thread != __current_cpu->idle_thread) {
tm_thread_block_confirm(&m->blocklist, THREADSTATE_UNINTERRUPTIBLE,
__confirm, m);
} else {
tm_schedule();
}
}
#if MUTEX_DEBUG
if(--timeout == 0) {
panic(0, "mutex timeout from %s:%d (owned by %d: %s:%d)\n", file, line, m->pid, m->owner_file, m->owner_line);
}
#endif
}
m->owner = current_thread;
m->owner_file = file;
m->owner_line = line;
}
int ahci_port_dma_data_transfer(struct hba_memory *abar, struct hba_port *port, struct ahci_device *dev, int slot, int write, addr_t virt_buffer, int sectors, uint64_t lba)
{
int timeout;
int fis_len = sizeof(struct fis_reg_host_to_device) / 4;
int ne = ahci_write_prdt(abar, port, dev,
slot, 0, ATA_SECTOR_SIZE * sectors, virt_buffer);
struct hba_command_header *h = ahci_initialize_command_header(abar,
port, dev, slot, write, 0, ne, fis_len);
struct fis_reg_host_to_device *fis = ahci_initialize_fis_host_to_device(abar,
port, dev, slot, 1, write ? ATA_CMD_WRITE_DMA_EX : ATA_CMD_READ_DMA_EX);
fis->device = 1<<6;
/* WARNING: assumes little-endian */
fis->count_l = sectors & 0xFF;
fis->count_h = (sectors >> 8) & 0xFF;
fis->lba0 = (unsigned char)( lba & 0xFF);
fis->lba1 = (unsigned char)((lba >> 8) & 0xFF);
fis->lba2 = (unsigned char)((lba >> 16) & 0xFF);
fis->lba3 = (unsigned char)((lba >> 24) & 0xFF);
fis->lba4 = (unsigned char)((lba >> 32) & 0xFF);
fis->lba5 = (unsigned char)((lba >> 40) & 0xFF);
port->sata_error = ~0;
timeout = ATA_TFD_TIMEOUT;
while ((port->task_file_data & (ATA_DEV_BUSY | ATA_DEV_DRQ)) && --timeout)
{
tm_schedule();
}
if(!timeout) goto port_hung;
port->sata_error = ~0;
ahci_send_command(port, slot);
timeout = ATA_TFD_TIMEOUT;
while ((port->task_file_data & (ATA_DEV_BUSY | ATA_DEV_DRQ)) && --timeout)
{
tm_schedule();
}
if(!timeout) goto port_hung;
timeout = AHCI_CMD_TIMEOUT;
while(--timeout)
{
if(!((port->sata_active | port->command_issue) & (1 << slot)))
break;
tm_schedule();
}
if(!timeout) goto port_hung;
if(port->sata_error)
{
printk(KERN_DEBUG, "[ahci]: device %d: ahci error\n", dev->idx);
goto error;
}
if(port->task_file_data & ATA_DEV_ERR)
{
printk(KERN_DEBUG, "[ahci]: device %d: task file data error\n", dev->idx);
goto error;
}
return 1;
port_hung:
printk(KERN_DEBUG, "[ahci]: device %d: port hung\n", dev->idx);
error:
printk(KERN_DEBUG, "[ahci]: device %d: tfd=%x, serr=%x\n",
dev->idx, port->task_file_data, port->sata_error);
ahci_reset_device(abar, port, dev);
return 0;
}