[PATCH] firmware: arm_sdei: Make sdei_list_lock a raw spinlock
Pierre Gondois
pierre.gondois at arm.com
Thu Aug 25 08:25:56 PDT 2022
On an Ampere Altra, running a preemp_rt kernel based on
v5.19-rc3-rt5, the following happens:
[ 15.683141] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
[ 15.683154] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0
[ 15.683157] preempt_count: 0, expected: 0
[ 15.683159] RCU nest depth: 0, expected: 0
[ 15.683163] 3 locks held by cpuhp/0/24:
[ 15.683167] #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248
[ 15.683201] #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248
[ 15.683205] #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130
[ 15.683224] irq event stamp: 36
[ 15.683226] hardirqs last enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0
[ 15.683236] hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248
[ 15.683238] softirqs last enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0
[ 15.683245] softirqs last disabled at (0): [<0000000000000000>] 0x0
[ 15.683258] CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...]
[ 15.683265] Hardware name: WIWYNN Mt.Jade Server System B81.03001.0005/Mt.Jade Motherboard, BIOS 1.08.20220218 (SCP: 1.08.20220218) 2022/02/18
[ 15.683268] Call trace:
[ 15.683271] dump_backtrace+0x114/0x120
[ 15.683277] show_stack+0x20/0x70
[ 15.683279] dump_stack_lvl+0x9c/0xd8
[ 15.683288] dump_stack+0x18/0x34
[ 15.683289] __might_resched+0x188/0x228
[ 15.683292] rt_spin_lock+0x70/0x120
[ 15.683301] sdei_cpuhp_up+0x3c/0x130
[ 15.683303] cpuhp_invoke_callback+0x250/0xf08
[ 15.683305] cpuhp_thread_fun+0x120/0x248
[ 15.683308] smpboot_thread_fn+0x280/0x320
[ 15.683315] kthread+0x130/0x140
[ 15.683321] ret_from_fork+0x10/0x20
sdei_cpuhp_up() is called in the STARTING hotplug section,
which runs whith interrupts disabled. Convert sdei_list_lock
to a raw spinlock to avoid sleeping with interrupt disabled.
Signed-off-by: Pierre Gondois <pierre.gondois at arm.com>
---
drivers/firmware/arm_sdei.c | 46 ++++++++++++++++++-------------------
1 file changed, 23 insertions(+), 23 deletions(-)
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index 1e1a51510e83..d2d596166f03 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -67,7 +67,7 @@ struct sdei_event {
static DEFINE_MUTEX(sdei_events_lock);
/* and then hold this when modifying the list */
-static DEFINE_SPINLOCK(sdei_list_lock);
+static DEFINE_RAW_SPINLOCK(sdei_list_lock);
static LIST_HEAD(sdei_list);
/* Private events are registered/enabled via IPI passing one of these */
@@ -167,14 +167,14 @@ static struct sdei_event *sdei_event_find(u32 event_num)
lockdep_assert_held(&sdei_events_lock);
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_for_each_entry(e, &sdei_list, list) {
if (e->event_num == event_num) {
found = e;
break;
}
}
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
return found;
}
@@ -259,9 +259,9 @@ static struct sdei_event *sdei_event_create(u32 event_num,
event->private_registered = regs;
}
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_add(&event->list, &sdei_list);
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
return event;
@@ -287,9 +287,9 @@ static void sdei_event_destroy_llocked(struct sdei_event *event)
static void sdei_event_destroy(struct sdei_event *event)
{
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
sdei_event_destroy_llocked(event);
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
}
static int sdei_api_get_version(u64 *version)
@@ -416,9 +416,9 @@ int sdei_event_enable(u32 event_num)
err = sdei_do_cross_call(_local_event_enable, event);
if (!err) {
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
event->reenable = true;
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
}
cpus_read_unlock();
mutex_unlock(&sdei_events_lock);
@@ -454,9 +454,9 @@ int sdei_event_disable(u32 event_num)
return -ENOENT;
}
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
event->reenable = false;
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
if (event->type == SDEI_EVENT_TYPE_SHARED)
err = sdei_api_event_disable(event->event_num);
@@ -501,10 +501,10 @@ int sdei_event_unregister(u32 event_num)
goto unlock;
}
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
event->reregister = false;
event->reenable = false;
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
if (event->type == SDEI_EVENT_TYPE_SHARED)
err = sdei_api_event_unregister(event->event_num);
@@ -531,7 +531,7 @@ static int sdei_unregister_shared(void)
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type != SDEI_EVENT_TYPE_SHARED)
continue;
@@ -540,7 +540,7 @@ static int sdei_unregister_shared(void)
if (err)
break;
}
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
mutex_unlock(&sdei_events_lock);
return err;
@@ -609,9 +609,9 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
goto cpu_unlock;
}
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
event->reregister = true;
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
cpu_unlock:
cpus_read_unlock();
unlock:
@@ -625,7 +625,7 @@ static int sdei_reregister_shared(void)
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type != SDEI_EVENT_TYPE_SHARED)
continue;
@@ -651,7 +651,7 @@ static int sdei_reregister_shared(void)
}
}
}
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
mutex_unlock(&sdei_events_lock);
return err;
@@ -663,7 +663,7 @@ static int sdei_cpuhp_down(unsigned int cpu)
int err;
/* un-register private events */
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type == SDEI_EVENT_TYPE_SHARED)
continue;
@@ -674,7 +674,7 @@ static int sdei_cpuhp_down(unsigned int cpu)
event->event_num, err);
}
}
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
return sdei_mask_local_cpu();
}
@@ -685,7 +685,7 @@ static int sdei_cpuhp_up(unsigned int cpu)
int err;
/* re-register/enable private events */
- spin_lock(&sdei_list_lock);
+ raw_spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type == SDEI_EVENT_TYPE_SHARED)
continue;
@@ -706,7 +706,7 @@ static int sdei_cpuhp_up(unsigned int cpu)
}
}
}
- spin_unlock(&sdei_list_lock);
+ raw_spin_unlock(&sdei_list_lock);
return sdei_unmask_local_cpu();
}
--
2.25.1
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