The following BUG was triggered. sugov_update_shared() locks a
raw_spinlock while cpc_write() locks a spinlock. To have a correct
wait-type order, update rmw_lock to a raw_spinlock.
Also save irq state.
=============================
[ BUG: Invalid wait context ]
6.12.0-rc2-XXX #406 Not tainted
-----------------------------
kworker/1:1/62 is trying to lock:
ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370
other info that might help us debug this:
context-{5:5}
2 locks held by kworker/1:1/62:
#0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50
#1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280
stack backtrace:
CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406
Workqueue: 0x0 (events)
Call trace:
dump_backtrace+0xa4/0x130
show_stack+0x20/0x38
dump_stack_lvl+0x90/0xd0
dump_stack+0x18/0x28
__lock_acquire+0x480/0x1ad8
lock_acquire+0x114/0x310
_raw_spin_lock+0x50/0x70
cpc_write+0xcc/0x370
cppc_set_perf+0xa0/0x3a8
cppc_cpufreq_fast_switch+0x40/0xc0
cpufreq_driver_fast_switch+0x4c/0x218
sugov_update_shared+0x234/0x280
update_load_avg+0x6ec/0x7b8
dequeue_entities+0x108/0x830
dequeue_task_fair+0x58/0x408
__schedule+0x4f0/0x1070
schedule+0x54/0x130
worker_thread+0xc0/0x2e8
kthread+0x130/0x148
ret_from_fork+0x10/0x20
Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage")
Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
---
Notes:
v2:
- Do the actual changes.
drivers/acpi/cppc_acpi.c | 9 +++++----
include/acpi/cppc_acpi.h | 2 +-
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index c3fc2c05d868..1a40f0514eaa 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -867,7 +867,7 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
/* Store CPU Logical ID */
cpc_ptr->cpu_id = pr->id;
- spin_lock_init(&cpc_ptr->rmw_lock);
+ raw_spin_lock_init(&cpc_ptr->rmw_lock);
/* Parse PSD data for this CPU */
ret = acpi_get_psd(cpc_ptr, handle);
@@ -1087,6 +1087,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
struct cpc_reg *reg = ®_res->cpc_entry.reg;
struct cpc_desc *cpc_desc;
+ unsigned long flags;
size = GET_BIT_WIDTH(reg);
@@ -1126,7 +1127,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
return -ENODEV;
}
- spin_lock(&cpc_desc->rmw_lock);
+ raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags);
switch (size) {
case 8:
prev_val = readb_relaxed(vaddr);
@@ -1141,7 +1142,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
prev_val = readq_relaxed(vaddr);
break;
default:
- spin_unlock(&cpc_desc->rmw_lock);
+ raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
return -EFAULT;
}
val = MASK_VAL_WRITE(reg, prev_val, val);
@@ -1174,7 +1175,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
}
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
- spin_unlock(&cpc_desc->rmw_lock);
+ raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
return ret_val;
}
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 76e44e102780..62d368bcd9ec 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -65,7 +65,7 @@ struct cpc_desc {
int write_cmd_status;
int write_cmd_id;
/* Lock used for RMW operations in cpc_write() */
- spinlock_t rmw_lock;
+ raw_spinlock_t rmw_lock;
struct cpc_register_resource cpc_regs[MAX_CPC_REG_ENT];
struct acpi_psd_package domain_info;
struct kobject kobj;
--
2.25.1
