diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index 1ead5ea6c5ce..4b5daa3cc0fe 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -57,6 +57,9 @@
*
* 2006-09-15 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
* Add printing support for MCA/INIT.
+ *
+ * 2007-04-27 Russ Anderson <rja@sgi.com>
+ * Support multiple cpus going through OS_MCA in the same event.
*/
#include <linux/types.h>
#include <linux/init.h>
@@ -96,7 +99,6 @@
#endif
/* Used by mca_asm.S */
-u32 ia64_mca_serialize;
DEFINE_PER_CPU(u64, ia64_mca_data); /* == __per_cpu_mca[smp_processor_id()] */
DEFINE_PER_CPU(u64, ia64_mca_per_cpu_pte); /* PTE to map per-CPU area */
DEFINE_PER_CPU(u64, ia64_mca_pal_pte); /* PTE to map PAL code */
@@ -963,11 +965,12 @@ ia64_mca_modify_original_stack(struct pt_regs *regs,
goto no_mod;
}
+ if (r13 != sos->prev_IA64_KR_CURRENT) {
+ msg = "inconsistent previous current and r13";
+ goto no_mod;
+ }
+
if (!mca_recover_range(ms->pmsa_iip)) {
- if (r13 != sos->prev_IA64_KR_CURRENT) {
- msg = "inconsistent previous current and r13";
- goto no_mod;
- }
if ((r12 - r13) >= KERNEL_STACK_SIZE) {
msg = "inconsistent r12 and r13";
goto no_mod;
@@ -1187,6 +1190,13 @@ all_in:
* further MCA logging is enabled by clearing logs.
* Monarch also has the duty of sending wakeup-IPIs to pull the
* slave processors out of rendezvous spinloop.
+ *
+ * If multiple processors call into OS_MCA, the first will become
+ * the monarch. Subsequent cpus will be recorded in the mca_cpu
+ * bitmask. After the first monarch has processed its MCA, it
+ * will wake up the next cpu in the mca_cpu bitmask and then go
+ * into the rendezvous loop. When all processors have serviced
+ * their MCA, the last monarch frees up the rest of the processors.
*/
void
ia64_mca_handler(struct pt_regs *regs, struct switch_stack *sw,
@@ -1196,16 +1206,32 @@ ia64_mca_handler(struct pt_regs *regs, struct switch_stack *sw,
struct task_struct *previous_current;
struct ia64_mca_notify_die nd =
{ .sos = sos, .monarch_cpu = &monarch_cpu };
+ static atomic_t mca_count;
+ static cpumask_t mca_cpu;
+ if (atomic_add_return(1, &mca_count) == 1) {
+ monarch_cpu = cpu;
+ sos->monarch = 1;
+ } else {
+ cpu_set(cpu, mca_cpu);
+ sos->monarch = 0;
+ }
mprintk(KERN_INFO "Entered OS MCA handler. PSP=%lx cpu=%d "
"monarch=%ld\n", sos->proc_state_param, cpu, sos->monarch);
previous_current = ia64_mca_modify_original_stack(regs, sw, sos, "MCA");
- monarch_cpu = cpu;
+
if (notify_die(DIE_MCA_MONARCH_ENTER, "MCA", regs, (long)&nd, 0, 0)
== NOTIFY_STOP)
ia64_mca_spin(__FUNCTION__);
- ia64_wait_for_slaves(cpu, "MCA");
+ if (sos->monarch) {
+ ia64_wait_for_slaves(cpu, "MCA");
+ } else {
+ ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_CONCURRENT_MCA;
+ while (cpu_isset(cpu, mca_cpu))
+ cpu_relax(); /* spin until monarch wakes us */
+ ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_NOTDONE;
+ }
/* Wakeup all the processors which are spinning in the rendezvous loop.
* They will leave SAL, then spin in the OS with interrupts disabled
@@ -1244,6 +1270,26 @@ ia64_mca_handler(struct pt_regs *regs, struct switch_stack *sw,
== NOTIFY_STOP)
ia64_mca_spin(__FUNCTION__);
+
+ if (atomic_dec_return(&mca_count) > 0) {
+ int i;
+
+ /* wake up the next monarch cpu,
+ * and put this cpu in the rendez loop.
+ */
+ ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_CONCURRENT_MCA;
+ for_each_online_cpu(i) {
+ if (cpu_isset(i, mca_cpu)) {
+ monarch_cpu = i;
+ cpu_clear(i, mca_cpu); /* wake next cpu */
+ while (monarch_cpu != -1)
+ cpu_relax(); /* spin until last cpu leaves */
+ ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_NOTDONE;
+ set_curr_task(cpu, previous_current);
+ return;
+ }
+ }
+ }
set_curr_task(cpu, previous_current);
monarch_cpu = -1;
}
diff --git a/arch/ia64/kernel/mca_asm.S b/arch/ia64/kernel/mca_asm.S
index 8c9c26aa6ae0..0f5965fcdf85 100644
--- a/arch/ia64/kernel/mca_asm.S
+++ b/arch/ia64/kernel/mca_asm.S
@@ -133,14 +133,6 @@ ia64_do_tlb_purge:
//StartMain////////////////////////////////////////////////////////////////////
ia64_os_mca_dispatch:
- // Serialize all MCA processing
- mov r3=1;;
- LOAD_PHYSICAL(p0,r2,ia64_mca_serialize);;
-ia64_os_mca_spin:
- xchg4 r4=[r2],r3;;
- cmp.ne p6,p0=r4,r0
-(p6) br ia64_os_mca_spin
-
mov r3=IA64_MCA_CPU_MCA_STACK_OFFSET // use the MCA stack
LOAD_PHYSICAL(p0,r2,1f) // return address
mov r19=1 // All MCA events are treated as monarch (for now)
@@ -291,10 +283,6 @@ END(ia64_os_mca_virtual_begin)
mov b0=r12 // SAL_CHECK return address
- // release lock
- LOAD_PHYSICAL(p0,r3,ia64_mca_serialize);;
- st4.rel [r3]=r0
-
br b0
//EndMain//////////////////////////////////////////////////////////////////////
diff --git a/include/asm-ia64/mca.h b/include/asm-ia64/mca.h
index 41098f459684..edd5d01028df 100644
--- a/include/asm-ia64/mca.h
+++ b/include/asm-ia64/mca.h
@@ -48,6 +48,7 @@ enum {
IA64_MCA_RENDEZ_CHECKIN_NOTDONE = 0x0,
IA64_MCA_RENDEZ_CHECKIN_DONE = 0x1,
IA64_MCA_RENDEZ_CHECKIN_INIT = 0x2,
+ IA64_MCA_RENDEZ_CHECKIN_CONCURRENT_MCA = 0x3,
};
/* Information maintained by the MC infrastructure */