in kernel/smp_64.c [483:624]
static void cheetah_xcall_deliver(struct trap_per_cpu *tb, int cnt)
{
int nack_busy_id, is_jbus, need_more;
u64 *mondo, pstate, ver, busy_mask;
u16 *cpu_list;
cpu_list = __va(tb->cpu_list_pa);
mondo = __va(tb->cpu_mondo_block_pa);
/* Unfortunately, someone at Sun had the brilliant idea to make the
* busy/nack fields hard-coded by ITID number for this Ultra-III
* derivative processor.
*/
__asm__ ("rdpr %%ver, %0" : "=r" (ver));
is_jbus = ((ver >> 32) == __JALAPENO_ID ||
(ver >> 32) == __SERRANO_ID);
__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
retry:
need_more = 0;
__asm__ __volatile__("wrpr %0, %1, %%pstate\n\t"
: : "r" (pstate), "i" (PSTATE_IE));
/* Setup the dispatch data registers. */
__asm__ __volatile__("stxa %0, [%3] %6\n\t"
"stxa %1, [%4] %6\n\t"
"stxa %2, [%5] %6\n\t"
"membar #Sync\n\t"
: /* no outputs */
: "r" (mondo[0]), "r" (mondo[1]), "r" (mondo[2]),
"r" (0x40), "r" (0x50), "r" (0x60),
"i" (ASI_INTR_W));
nack_busy_id = 0;
busy_mask = 0;
{
int i;
for (i = 0; i < cnt; i++) {
u64 target, nr;
nr = cpu_list[i];
if (nr == 0xffff)
continue;
target = (nr << 14) | 0x70;
if (is_jbus) {
busy_mask |= (0x1UL << (nr * 2));
} else {
target |= (nack_busy_id << 24);
busy_mask |= (0x1UL <<
(nack_busy_id * 2));
}
__asm__ __volatile__(
"stxa %%g0, [%0] %1\n\t"
"membar #Sync\n\t"
: /* no outputs */
: "r" (target), "i" (ASI_INTR_W));
nack_busy_id++;
if (nack_busy_id == 32) {
need_more = 1;
break;
}
}
}
/* Now, poll for completion. */
{
u64 dispatch_stat, nack_mask;
long stuck;
stuck = 100000 * nack_busy_id;
nack_mask = busy_mask << 1;
do {
__asm__ __volatile__("ldxa [%%g0] %1, %0"
: "=r" (dispatch_stat)
: "i" (ASI_INTR_DISPATCH_STAT));
if (!(dispatch_stat & (busy_mask | nack_mask))) {
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
if (unlikely(need_more)) {
int i, this_cnt = 0;
for (i = 0; i < cnt; i++) {
if (cpu_list[i] == 0xffff)
continue;
cpu_list[i] = 0xffff;
this_cnt++;
if (this_cnt == 32)
break;
}
goto retry;
}
return;
}
if (!--stuck)
break;
} while (dispatch_stat & busy_mask);
__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
: : "r" (pstate));
if (dispatch_stat & busy_mask) {
/* Busy bits will not clear, continue instead
* of freezing up on this cpu.
*/
printk("CPU[%d]: mondo stuckage result[%016llx]\n",
smp_processor_id(), dispatch_stat);
} else {
int i, this_busy_nack = 0;
/* Delay some random time with interrupts enabled
* to prevent deadlock.
*/
udelay(2 * nack_busy_id);
/* Clear out the mask bits for cpus which did not
* NACK us.
*/
for (i = 0; i < cnt; i++) {
u64 check_mask, nr;
nr = cpu_list[i];
if (nr == 0xffff)
continue;
if (is_jbus)
check_mask = (0x2UL << (2*nr));
else
check_mask = (0x2UL <<
this_busy_nack);
if ((dispatch_stat & check_mask) == 0)
cpu_list[i] = 0xffff;
this_busy_nack += 2;
if (this_busy_nack == 64)
break;
}
goto retry;
}
}
}