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/*
* core/fs/pxe/isr.c
*
* Stub invoked on return from real mode including from an interrupt.
* Interrupts are locked out on entry.
*/
#include "core.h"
#include "thread.h"
#include "pxe.h"
#include <string.h>
extern uint8_t pxe_irq_pending;
static DECLARE_INIT_SEMAPHORE(pxe_receive_thread_sem, 0);
static struct thread *pxe_thread, *poll_thread;
static bool install_irq_vector(uint8_t irq, void (*isr)(void), far_ptr_t *old)
{
far_ptr_t *entry;
unsigned int vec;
if (irq < 8)
vec = irq + 0x08;
else if (irq < 16)
vec = (irq - 8) + 0x70;
else
return false;
entry = (far_ptr_t *)(vec << 2);
*old = *entry;
entry->ptr = (uint32_t)isr;
printf("UNDI: IRQ %d(0x%02x): %04x:%04x -> %04x:%04x\n", irq, vec,
old->seg, old->offs, entry->seg, entry->offs);
return true;
}
static bool uninstall_irq_vector(uint8_t irq, void (*isr), far_ptr_t *old)
{
far_ptr_t *entry;
unsigned int vec;
if (!irq)
return true; /* Nothing to uninstall */
if (irq < 8)
vec = irq + 0x08;
else if (irq < 16)
vec = (irq - 8) + 0x70;
else
return false;
entry = (far_ptr_t *)(vec << 2);
if (entry->ptr != (uint32_t)isr)
return false;
*entry = *old;
return true;
}
static void pxe_poll_wakeups(void)
{
static jiffies_t last_jiffies = 0;
jiffies_t now = jiffies();
if (now != last_jiffies) {
last_jiffies = now;
__thread_process_timeouts();
}
if (pxe_irq_pending) {
pxe_irq_pending = 0;
sem_up(&pxe_receive_thread_sem);
}
}
static void pxe_process_irq(void)
{
static __lowmem t_PXENV_UNDI_ISR isr;
uint16_t func = PXENV_UNDI_ISR_IN_PROCESS; /* First time */
bool done = false;
while (!done) {
memset(&isr, 0, sizeof isr);
isr.FuncFlag = func;
func = PXENV_UNDI_ISR_IN_GET_NEXT; /* Next time */
pxe_call(PXENV_UNDI_ISR, &isr);
switch (isr.FuncFlag) {
case PXENV_UNDI_ISR_OUT_DONE:
done = true;
break;
case PXENV_UNDI_ISR_OUT_TRANSMIT:
/* Transmit complete - nothing for us to do */
break;
case PXENV_UNDI_ISR_OUT_RECEIVE:
undiif_input(&isr);
break;
case PXENV_UNDI_ISR_OUT_BUSY:
/* ISR busy, this should not happen */
done = true;
break;
default:
/* Invalid return code, this should not happen */
done = true;
break;
}
}
}
static void pxe_receive_thread(void *dummy)
{
(void)dummy;
for (;;) {
sem_down(&pxe_receive_thread_sem, 0);
pxe_process_irq();
}
}
static bool pxe_isr_poll(void)
{
static __lowmem t_PXENV_UNDI_ISR isr;
isr.FuncFlag = PXENV_UNDI_ISR_IN_START;
pxe_call(PXENV_UNDI_ISR, &isr);
return isr.FuncFlag == PXENV_UNDI_ISR_OUT_OURS;
}
static void pxe_poll_thread(void *dummy)
{
(void)dummy;
for (;;) {
thread_yield();
if (pxe_isr_poll())
sem_up(&pxe_receive_thread_sem);
}
}
/*
* This does preparations and enables the PXE thread
*/
void pxe_init_isr(void)
{
start_idle_thread();
sched_hook_func = pxe_poll_wakeups;
/*
* Run the pxe receive thread at elevated priority, since the UNDI
* stack is likely to have very limited memory available; therefore to
* avoid packet loss we need to move it into memory that we ourselves
* manage, as soon as possible.
*/
pxe_thread = start_thread("pxe receive", 16384, -20,
pxe_receive_thread, NULL);
core_pm_hook = __schedule;
}
/*
* Actually start the interrupt routine inside the UNDI stack
*/
void pxe_start_isr(void)
{
pxe_irq_vector = pxe_undi_info.IntNumber; /* Used in 16-bit code */
if (pxe_undi_info.IntNumber)
install_irq_vector(pxe_undi_info.IntNumber, pxe_isr, &pxe_irq_chain);
if (!pxe_undi_info.IntNumber ||
!(pxe_undi_iface.ServiceFlags & PXE_UNDI_IFACE_FLAG_IRQ))
poll_thread = start_thread("pxe poll", 4096, POLL_THREAD_PRIORITY,
pxe_poll_thread, NULL);
}
void pxe_cleanup_isr(void)
{
static __lowmem struct s_PXENV_UNDI_CLOSE undi_close;
sched_hook_func = NULL;
core_pm_hook = core_pm_null_hook;
kill_thread(pxe_thread);
memset(&undi_close, 0, sizeof(undi_close));
pxe_call(PXENV_UNDI_CLOSE, &undi_close);
if (pxe_undi_info.IntNumber)
uninstall_irq_vector(pxe_undi_info.IntNumber, pxe_isr, &pxe_irq_chain);
if (poll_thread)
kill_thread(poll_thread);
}
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