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Diffstat (limited to 'arch/xtensa/kernel')
-rw-r--r--arch/xtensa/kernel/head.S5
-rw-r--r--arch/xtensa/kernel/smp.c41
-rw-r--r--arch/xtensa/kernel/time.c2
3 files changed, 32 insertions, 16 deletions
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index c7b3bedbfffe..e3823b4f9d08 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -286,12 +286,13 @@ should_never_return:
movi a2, cpu_start_ccount
1:
+ memw
l32i a3, a2, 0
beqi a3, 0, 1b
movi a3, 0
s32i a3, a2, 0
- memw
1:
+ memw
l32i a3, a2, 0
beqi a3, 0, 1b
wsr a3, ccount
@@ -328,11 +329,13 @@ ENTRY(cpu_restart)
rsr a0, prid
neg a2, a0
movi a3, cpu_start_id
+ memw
s32i a2, a3, 0
#if XCHAL_DCACHE_IS_WRITEBACK
dhwbi a3, 0
#endif
1:
+ memw
l32i a2, a3, 0
dhi a3, 0
bne a2, a0, 1b
diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 4d02e38514f5..54bb8e0473a0 100644
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -80,7 +80,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned i;
- for (i = 0; i < max_cpus; ++i)
+ for_each_possible_cpu(i)
set_cpu_present(i, true);
}
@@ -93,6 +93,11 @@ void __init smp_init_cpus(void)
pr_info("%s: Core Count = %d\n", __func__, ncpus);
pr_info("%s: Core Id = %d\n", __func__, core_id);
+ if (ncpus > NR_CPUS) {
+ ncpus = NR_CPUS;
+ pr_info("%s: limiting core count by %d\n", __func__, ncpus);
+ }
+
for (i = 0; i < ncpus; ++i)
set_cpu_possible(i, true);
}
@@ -192,9 +197,11 @@ static int boot_secondary(unsigned int cpu, struct task_struct *ts)
int i;
#ifdef CONFIG_HOTPLUG_CPU
- cpu_start_id = cpu;
- system_flush_invalidate_dcache_range(
- (unsigned long)&cpu_start_id, sizeof(cpu_start_id));
+ WRITE_ONCE(cpu_start_id, cpu);
+ /* Pairs with the third memw in the cpu_restart */
+ mb();
+ system_flush_invalidate_dcache_range((unsigned long)&cpu_start_id,
+ sizeof(cpu_start_id));
#endif
smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1);
@@ -203,18 +210,21 @@ static int boot_secondary(unsigned int cpu, struct task_struct *ts)
ccount = get_ccount();
while (!ccount);
- cpu_start_ccount = ccount;
+ WRITE_ONCE(cpu_start_ccount, ccount);
- while (time_before(jiffies, timeout)) {
+ do {
+ /*
+ * Pairs with the first two memws in the
+ * .Lboot_secondary.
+ */
mb();
- if (!cpu_start_ccount)
- break;
- }
+ ccount = READ_ONCE(cpu_start_ccount);
+ } while (ccount && time_before(jiffies, timeout));
- if (cpu_start_ccount) {
+ if (ccount) {
smp_call_function_single(0, mx_cpu_stop,
- (void *)cpu, 1);
- cpu_start_ccount = 0;
+ (void *)cpu, 1);
+ WRITE_ONCE(cpu_start_ccount, 0);
return -EIO;
}
}
@@ -234,6 +244,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
pr_debug("%s: Calling wakeup_secondary(cpu:%d, idle:%p, sp: %08lx)\n",
__func__, cpu, idle, start_info.stack);
+ init_completion(&cpu_running);
ret = boot_secondary(cpu, idle);
if (ret == 0) {
wait_for_completion_timeout(&cpu_running,
@@ -295,8 +306,10 @@ void __cpu_die(unsigned int cpu)
unsigned long timeout = jiffies + msecs_to_jiffies(1000);
while (time_before(jiffies, timeout)) {
system_invalidate_dcache_range((unsigned long)&cpu_start_id,
- sizeof(cpu_start_id));
- if (cpu_start_id == -cpu) {
+ sizeof(cpu_start_id));
+ /* Pairs with the second memw in the cpu_restart */
+ mb();
+ if (READ_ONCE(cpu_start_id) == -cpu) {
platform_cpu_kill(cpu);
return;
}
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index b9ad9feadc2d..a992cb6a47db 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -87,7 +87,7 @@ static int ccount_timer_shutdown(struct clock_event_device *evt)
container_of(evt, struct ccount_timer, evt);
if (timer->irq_enabled) {
- disable_irq(evt->irq);
+ disable_irq_nosync(evt->irq);
timer->irq_enabled = 0;
}
return 0;