uintptr_t htif_interrupt(uintptr_t mcause, uintptr_t* regs) {
uintptr_t fromhost = swap_csr(mfromhost, 0);
if (!fromhost)
return 0;
uintptr_t dev = FROMHOST_DEV(fromhost);
uintptr_t cmd = FROMHOST_CMD(fromhost);
uintptr_t data = FROMHOST_DATA(fromhost);
sbi_device_message* m = HLS()->device_request_queue_head;
sbi_device_message* prev = 0x0;
unsigned long i, n;
for (i = 0, n = HLS()->device_request_queue_size; i < n; i++) {
/*
if (!supervisor_paddr_valid(m, sizeof(*m))
&& EXTRACT_FIELD(read_csr(mstatus), MSTATUS_PRV1) != PRV_M)
panic("htif: page fault");
*/
sbi_device_message* next = (void*)m->sbi_private_data;
if (m->dev == dev && m->cmd == cmd) {
m->data = data;
// dequeue from request queue
if (prev)
prev->sbi_private_data = (uintptr_t)next;
else
HLS()->device_request_queue_head = next;
HLS()->device_request_queue_size = n-1;
m->sbi_private_data = 0;
// enqueue to response queue
if (HLS()->device_response_queue_tail)
{
HLS()->device_response_queue_tail->sbi_private_data = (uintptr_t)m;
}
else
{
HLS()->device_response_queue_head = m;
}
HLS()->device_response_queue_tail = m;
// signal software interrupt
set_csr(mip, MIP_SSIP);
return 0;
}
prev = m;
m = (void*)atomic_read(&m->sbi_private_data);
}
//HLT();
return 0;
//panic("htif: no record");
}
static void do_tohost_fromhost(uintptr_t dev, uintptr_t cmd, uintptr_t data)
{
__set_tohost(dev, cmd, data);
while (1) {
uint64_t fh = fromhost;
if (fh) {
if (FROMHOST_DEV(fh) == dev && FROMHOST_CMD(fh) == cmd) {
fromhost = 0;
break;
}
__check_fromhost();
}
}
}
uintptr_t mcall_console_putchar(uint8_t ch)
{
while (swap_csr(mtohost, TOHOST_CMD(1, 1, ch)) != 0);
while (1) {
uintptr_t fromhost = read_csr(mfromhost);
if (FROMHOST_DEV(fromhost) != 1 || FROMHOST_CMD(fromhost) != 1) {
if (fromhost)
htif_interrupt(0, 0);
continue;
}
write_csr(mfromhost, 0);
break;
}
return 0;
}
static void __check_fromhost()
{
uint64_t fh = fromhost;
if (!fh)
return;
fromhost = 0;
// this should be from the console
assert(FROMHOST_DEV(fh) == 1);
switch (FROMHOST_CMD(fh)) {
case 0:
htif_console_buf = 1 + (uint8_t)FROMHOST_DATA(fh);
break;
case 1:
break;
default:
assert(0);
}
}