summaryrefslogtreecommitdiff
path: root/drivers/iommu/intel/iommu.c
diff options
context:
space:
mode:
authorZhang Rui <rui.zhang@intel.com>2023-09-25 20:04:17 +0800
committerJoerg Roedel <jroedel@suse.de>2023-09-25 16:10:36 +0200
commit59df44bfb0ca4c3ee1f1c3c5d0ee8e314844799e (patch)
tree9788b303e395dbb931b85409d4f8267e5b87ddea /drivers/iommu/intel/iommu.c
parentc7bd8a1f45bada7725d11266df7fd5cb549b3098 (diff)
iommu/vt-d: Avoid memory allocation in iommu_suspend()
The iommu_suspend() syscore suspend callback is invoked with IRQ disabled. Allocating memory with the GFP_KERNEL flag may re-enable IRQs during the suspend callback, which can cause intermittent suspend/hibernation problems with the following kernel traces: Calling iommu_suspend+0x0/0x1d0 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 15 at kernel/time/timekeeping.c:868 ktime_get+0x9b/0xb0 ... CPU: 0 PID: 15 Comm: rcu_preempt Tainted: G U E 6.3-intel #r1 RIP: 0010:ktime_get+0x9b/0xb0 ... Call Trace: <IRQ> tick_sched_timer+0x22/0x90 ? __pfx_tick_sched_timer+0x10/0x10 __hrtimer_run_queues+0x111/0x2b0 hrtimer_interrupt+0xfa/0x230 __sysvec_apic_timer_interrupt+0x63/0x140 sysvec_apic_timer_interrupt+0x7b/0xa0 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1f/0x30 ... ------------[ cut here ]------------ Interrupts enabled after iommu_suspend+0x0/0x1d0 WARNING: CPU: 0 PID: 27420 at drivers/base/syscore.c:68 syscore_suspend+0x147/0x270 CPU: 0 PID: 27420 Comm: rtcwake Tainted: G U W E 6.3-intel #r1 RIP: 0010:syscore_suspend+0x147/0x270 ... Call Trace: <TASK> hibernation_snapshot+0x25b/0x670 hibernate+0xcd/0x390 state_store+0xcf/0xe0 kobj_attr_store+0x13/0x30 sysfs_kf_write+0x3f/0x50 kernfs_fop_write_iter+0x128/0x200 vfs_write+0x1fd/0x3c0 ksys_write+0x6f/0xf0 __x64_sys_write+0x1d/0x30 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Given that only 4 words memory is needed, avoid the memory allocation in iommu_suspend(). CC: stable@kernel.org Fixes: 33e07157105e ("iommu/vt-d: Avoid GFP_ATOMIC where it is not needed") Signed-off-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Ooi, Chin Hao <chin.hao.ooi@intel.com> Link: https://lore.kernel.org/r/20230921093956.234692-1-rui.zhang@intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20230925120417.55977-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel/iommu.c')
-rw-r--r--drivers/iommu/intel/iommu.c16
1 files changed, 0 insertions, 16 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 5db283c17e0d..3685ba90ec88 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2998,13 +2998,6 @@ static int iommu_suspend(void)
struct intel_iommu *iommu = NULL;
unsigned long flag;
- for_each_active_iommu(iommu, drhd) {
- iommu->iommu_state = kcalloc(MAX_SR_DMAR_REGS, sizeof(u32),
- GFP_KERNEL);
- if (!iommu->iommu_state)
- goto nomem;
- }
-
iommu_flush_all();
for_each_active_iommu(iommu, drhd) {
@@ -3024,12 +3017,6 @@ static int iommu_suspend(void)
raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
}
return 0;
-
-nomem:
- for_each_active_iommu(iommu, drhd)
- kfree(iommu->iommu_state);
-
- return -ENOMEM;
}
static void iommu_resume(void)
@@ -3061,9 +3048,6 @@ static void iommu_resume(void)
raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
}
-
- for_each_active_iommu(iommu, drhd)
- kfree(iommu->iommu_state);
}
static struct syscore_ops iommu_syscore_ops = {