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authorPierre Gondois <pierre.gondois@arm.com>2024-10-28 13:56:56 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2024-10-29 12:56:19 +0100
commit1c10941e34c5fdc0357e46a25bd130d9cf40b925 (patch)
tree3aff2fae586d032bf9b95ae7c0396df5ea70587c /drivers/acpi/cppc_acpi.c
parent81983758430957d9a5cb3333fe324fd70cf63e7e (diff)
ACPI: CPPC: Make rmw_lock a raw_spin_lock
The following BUG was triggered: ============================= [ 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 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 and ensure that interrupts will be disabled on the CPU holding it. Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage") Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://patch.msgid.link/20241028125657.1271512-1-pierre.gondois@arm.com [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
-rw-r--r--drivers/acpi/cppc_acpi.c9
1 files changed, 5 insertions, 4 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 = &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;
}